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Fraleigh DC, Pallin LJ, Friedlaender AS, Barlow J, Henry AE, Waples DM, Oglesby T, Fleming AH. The influence of biopsy site and pregnancy on stable isotope ratios in humpback whale skin. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2024; 38:e9746. [PMID: 38576213 DOI: 10.1002/rcm.9746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Revised: 02/20/2024] [Accepted: 03/13/2024] [Indexed: 04/06/2024]
Abstract
RATIONALE Stable isotope analysis (SIA) of free-swimming mysticetes using biopsies is often limited in sample size and uses only one sample per individual, failing to capture both intra-individual variability and the influence of demographic and physiological factors on isotope ratios. METHODS We applied SIA of δ13C and δ15N to humpback whale (Megaptera novaeangliae) biopsies taken during the foraging season along the western Antarctic Peninsula to quantify intra-individual variation from repeatedly sampled individuals, as well as to determine the effect of biopsy collection site, sex, and pregnancy on isotope ratios. RESULTS There was substantial variability in δ13C from multiple biopsies taken from the same individuals, though δ15N was much more consistent. Side of the body (left versus right) and biopsy location (dorsal, anterior, ventral, and posterior) did marginally affect the isotopic composition of δ15N but not δ13C. Pregnancy had a significant effect on both δ13C and δ15N, where pregnant females were depleted in both when compared to non-pregnant females and males. CONCLUSIONS These results indicate that isotopic signatures are influenced by multiple endogenous and exogenous factors and emphasize value in accounting for intra-individual variability and pregnancy status within a sampled population. Placed within an ecological context, the endogenous variability in δ13C observed here may be informative for future isotopic analyses.
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Affiliation(s)
- Devin C Fraleigh
- Center for Marine Science, University of North Carolina Wilmington, Wilmington, North Carolina, USA
- Department of Oceanography, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Logan J Pallin
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, California, USA
| | - Ari S Friedlaender
- Institute for Marine Science, University of California Santa Cruz, Santa Cruz, California, USA
- Department of Ocean Sciences, University of California Santa Cruz, Santa Cruz, California, USA
| | - Jay Barlow
- NOAA Southwest Fisheries Science Center, San Diego, California, USA
| | - Annette E Henry
- NOAA Southwest Fisheries Science Center, San Diego, California, USA
| | | | - Teris Oglesby
- Duke University Marine Laboratory, Beaufort, North Carolina, USA
| | - Alyson H Fleming
- Center for Marine Science, University of North Carolina Wilmington, Wilmington, North Carolina, USA
- Department of Forest & Wildlife Ecology, University of Wisconsin-Madison, Madison, Wisconsin, USA
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2
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Storlund RL, Cottrell PE, Cottrell B, Roth M, Lehnhart T, Snyman H, Trites AW, Raverty SA. Aquaculture related humpback whale entanglements in coastal waters of British Columbia from 2008-2021. PLoS One 2024; 19:e0297768. [PMID: 38507405 PMCID: PMC10954164 DOI: 10.1371/journal.pone.0297768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 01/11/2024] [Indexed: 03/22/2024] Open
Abstract
Over the past two decades, increasing numbers of humpback whales have been returning to feed in the inshore waters of British Columbia (BC) where marine aquaculture farms are situated. This has led to growing concerns that the presence of aquaculture farms may pose an entanglement threat to humpback whales. However, it is not known whether aquaculture facilities attract humpback whales, or whether there are factors that increase the likelihood of humpback whale, becoming entangled and dying. We examined eight reports of humpback whales interacting with Atlantic salmon farms in BC from 2008 to 2021 to evaluate the conditions that may have contributed to their entanglements. Of the eight entangled humpbacks, three individuals died and five were successfully disentangled and released. All were young animals (1 calf, 7 subadults). Multiple factors were associated with two or more of the reported incidents. These included facility design, environmental features, seasonality, humpback whale age, and feeding behaviour. We found that humpback whales were most commonly entrapped in the predator nets of the aquaculture facilities (6/8 incidents), and were less often entangled in anchor support lines (2/8). The presence of salmon smolts did not appear to be an attractant for humpback whales given that half of the reported entanglements (4/8) occurred at fallowed salmon farms. Almost all of the entanglements (7/8) occurred in late winter (prior to the seasonal return of humpbacks) and during late fall (after most humpbacks have migrated south). Overall, the number of humpback whales impacted by fish farms was small compared to the numbers that return to BC (> 7,000) and accounted for <6% of all types of reported entanglements in BC. Human intervention was required to release humpback whales at fish farms, which points to the need to have well-established protocols to minimize entanglements and maximize successful releases.
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Affiliation(s)
- Rhea L. Storlund
- Marine Mammal Research Unit, Institute for the Oceans and Fisheries, University of British Columbia, Vancouver, BC, Canada
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
| | - Paul E. Cottrell
- Fisheries and Oceans Canada, Fisheries and Aquaculture Management, Vancouver, BC, Canada
| | - Brendan Cottrell
- Applied Remote Sensing Lab, Department of Geography, McGill University, Montreal, QC, Canada
| | - Myron Roth
- Aquaculture and Marine Fisheries, BC Ministry of Agriculture and Food, Victoria, BC, Canada
| | - Taylor Lehnhart
- Fisheries and Oceans Canada, Fisheries and Aquaculture Management, Vancouver, BC, Canada
| | - Heindrich Snyman
- Animal Health Laboratory, Laboratory Services Division, University of Guelph, Kemptville, ON, Canada
| | - Andrew W. Trites
- Marine Mammal Research Unit, Institute for the Oceans and Fisheries, University of British Columbia, Vancouver, BC, Canada
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
| | - Stephen A. Raverty
- Marine Mammal Research Unit, Institute for the Oceans and Fisheries, University of British Columbia, Vancouver, BC, Canada
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
- Animal Health Center, Ministry of Agriculture, Abbotsford, BC, Canada
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3
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Romero J, Alonso H, Freitas L, Granadeiro JP. Food web of the oceanic region of the archipelago of Madeira: The role of marine megafauna in the subtropical northeast Atlantic ecosystem. MARINE ENVIRONMENTAL RESEARCH 2024; 195:106382. [PMID: 38309039 DOI: 10.1016/j.marenvres.2024.106382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 01/25/2024] [Accepted: 01/26/2024] [Indexed: 02/05/2024]
Abstract
Many oceanic areas are still in need of baseline information on their structure and functioning. This is particularly important due to the ever-increasing impacts of global changes, which have led to the decline of marine life, and top predators in particular. The study of the structure and functioning of food webs can help understand the consequences of the disappearance of this group in marine ecosystems. Here, we develop a mass-balanced model for the marine Exclusive Economic Zone of the archipelago of Madeira, with emphasis on the role of marine megafauna in this ecosystem. A total of 50 functional groups were defined, representing coastal and open ocean areas, and epipelagic and deep-sea levels. The total biomass of the Madeira system was calculated at 52.68 t km-2, with lower trophic level organisms comprising 89.9 % of its biomass. Marine megafauna, namely pelagic sharks and coastal birds had the highest impacts across other trophic levels and were classified as keystone species, together with monk seals. The food web was characterized by a linear-like food chain, with a large proportion of specialized organisms, including dolphins, shearwaters, and large pelagic fish. The low mean trophic level of the system was 2.03, much lower than that of fisheries (4.3) targeting mainly tunas and Black scabbardfish. Considering the importance of marine megafauna in this food web and the threats they are facing; monitoring studies of key species in the region should be a priority. This study can now be used to build a needed ecosystem-based fisheries management and integrate conservation measures to declining species.
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Affiliation(s)
- Joana Romero
- Centre for Environmental and Marine Studies (CESAM), Departamento de Biologia Animal, Faculdade de Ciências da Universidade de Lisboa, Campo Grande, 1749-016, Lisbon, Portugal.
| | - Hany Alonso
- Sociedade Portuguesa para o Estudo das Aves, Av. Alm. Gago Coutinho 46A, 1700-031, Lisbon, Portugal
| | - Luís Freitas
- Museu da Baleia da Madeira, Rua Garcia Moniz 1, 9200-031, Caniçal, Madeira, Portugal
| | - José Pedro Granadeiro
- Centre for Environmental and Marine Studies (CESAM), Departamento de Biologia Animal, Faculdade de Ciências da Universidade de Lisboa, Campo Grande, 1749-016, Lisbon, Portugal
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Cheeseman T, Barlow J, Acebes JM, Audley K, Bejder L, Birdsall C, Bracamontes OS, Bradford AL, Byington J, Calambokidis J, Cartwright R, Cedarleaf J, Chavez AJG, Currie J, De Castro RC, De Weerdt J, Doe N, Doniol-Valcroze T, Dracott K, Filatova O, Finn R, Flynn KR, Ford J, Frisch-Jordán A, Gabriele C, Goodwin B, Hayslip C, Hildering J, Hill MC, Jacobsen JK, Jiménez-López ME, Jones M, Kobayashi N, Lammers M, Lyman E, Malleson M, Mamaev E, Loustalot PM, Masterman A, Matkin CO, McMillan C, Moore J, Moran J, Neilson JL, Newell H, Okabe H, Olio M, Ortega-Ortiz CD, Pack AA, Palacios DM, Pearson H, Quintana-Rizzo E, Barragán RR, Ransome N, Rosales-Nanduca H, Sharpe F, Shaw T, Southerland K, Stack S, Staniland I, Straley J, Szabo A, Teerlink S, Titova O, Urban-Ramirez J, van Aswegen M, Vinicius M, von Ziegesar O, Witteveen B, Wray J, Yano K, Yegin I, Zwiefelhofer D, Clapham P. Bellwethers of change: population modelling of North Pacific humpback whales from 2002 through 2021 reveals shift from recovery to climate response. ROYAL SOCIETY OPEN SCIENCE 2024; 11:231462. [PMID: 38420629 PMCID: PMC10898971 DOI: 10.1098/rsos.231462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 01/15/2024] [Indexed: 03/02/2024]
Abstract
For the 40 years after the end of commercial whaling in 1976, humpback whale populations in the North Pacific Ocean exhibited a prolonged period of recovery. Using mark-recapture methods on the largest individual photo-identification dataset ever assembled for a cetacean, we estimated annual ocean-basin-wide abundance for the species from 2002 through 2021. Trends in annual estimates describe strong post-whaling era population recovery from 16 875 (± 5955) in 2002 to a peak abundance estimate of 33 488 (± 4455) in 2012. An apparent 20% decline from 2012 to 2021, 33 488 (± 4455) to 26 662 (± 4192), suggests the population abruptly reached carrying capacity due to loss of prey resources. This was particularly evident for humpback whales wintering in Hawai'i, where, by 2021, estimated abundance had declined by 34% from a peak in 2013, down to abundance levels previously seen in 2006, and contrasted to an absence of decline in Mainland Mexico breeding humpbacks. The strongest marine heatwave recorded globally to date during the 2014-2016 period appeared to have altered the course of species recovery, with enduring effects. Extending this time series will allow humpback whales to serve as an indicator species for the ecosystem in the face of a changing climate.
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Affiliation(s)
- Ted Cheeseman
- Marine Ecology Research Centre, Southern Cross University, Lismore, New South Wales, Australia
- Happywhale, Santa Cruz, CA, USA
| | - Jay Barlow
- Marine Mammal Institute, Oregon State University, Newport, OR, USA
| | | | | | - Lars Bejder
- Marine Mammal Research Program, Hawai'i Institute of Marine Biology, University of Hawai'i at Manoa, Kaneohe, HI, USA
| | - Caitlin Birdsall
- Marine Education and Research Society, Port McNeill, British Columbia, Canada
| | | | - Amanda L Bradford
- NOAA Fisheries Pacific Islands Fisheries Science Center, Honolulu, HI, USA
| | - Josie Byington
- Pacific Wildlife Foundation Canada, Port Moody, British Columbia, Canada
| | | | - Rachel Cartwright
- The Keiki Kohola Project, Delray Beach, FL, USA
- California State University Channel Islands, Camarillo, CA, USA
| | - Jen Cedarleaf
- University of Alaska Southeast, Sitka Campus, Sitka, AK, USA
| | | | | | | | - Joëlle De Weerdt
- Association ELI-S, Gujan-Mestras, France
- Vrije Universiteit, Brussels, Belgium
| | - Nicole Doe
- Marine Education and Research Society, Port McNeill, British Columbia, Canada
| | - Thomas Doniol-Valcroze
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, British Columbia, Canada
| | | | - Olga Filatova
- Department of Biology, University of Southern Denmark, Odense, Denmark
| | - Rachel Finn
- Hawaiian Islands Humpback Whale National Marine Sanctuary, Kīhei, HI, USA
| | | | - John Ford
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, British Columbia, Canada
| | | | - Chris Gabriele
- Hawai'i Marine Mammal Consortium, Waimea, HI, USA
- Glacier Bay National Park and Preserve, Gustavus, AK, USA
| | - Beth Goodwin
- Eye of the Whale Marine Mammal Research, Kamuela, HI, USA
| | - Craig Hayslip
- Marine Mammal Institute, Oregon State University, Newport, OR, USA
| | - Jackie Hildering
- Marine Education and Research Society, Port McNeill, British Columbia, Canada
| | - Marie C Hill
- NOAA Fisheries Pacific Islands Fisheries Science Center, Honolulu, HI, USA
- Cooperative Institute for Marine and Atmospheric Research, Research Corporation of the University of Hawai'i, Honolulu, HI, USA
| | | | - M Esther Jiménez-López
- Departamento Académico de Ingeniería en Pesquerías, Universidad Autónoma de Baja California Sur, La Paz, BCS, Mexico
| | | | | | - Marc Lammers
- Hawaiian Islands Humpback Whale National Marine Sanctuary, Kīhei, HI, USA
| | - Edward Lyman
- Hawaiian Islands Humpback Whale National Marine Sanctuary, Kīhei, HI, USA
| | | | - Evgeny Mamaev
- FGBU Gosudarstvennyj zapovednik Komandorskij, Commander Islands, Kamchatka Krai, Russia
| | | | - Annie Masterman
- National Marine Fisheries Service, NOAA, Auke Bay Laboratories, Alaska Fisheries Science Center, Juneau, AK, USA
| | | | - Christie McMillan
- Marine Education and Research Society, Port McNeill, British Columbia, Canada
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, British Columbia, Canada
| | - Jeff Moore
- NOAA Fisheries Southwest Fisheries Science Center, La Jolla, CA, USA
| | - John Moran
- National Marine Fisheries Service, NOAA, Auke Bay Laboratories, Alaska Fisheries Science Center, Juneau, AK, USA
| | | | | | | | | | | | - Adam A Pack
- Department of Psychology, University of Hawai'i at Hilo, Hilo, HI, USA
- The Dolphin Institute, Hilo, HI, USA
| | | | | | | | | | - Nicola Ransome
- College of Sustainable Aquatic Ecosystems, Harry Butler Institute, Murdoch University, Western Australia, Australia
| | - Hiram Rosales-Nanduca
- Departamento Académico de Ingeniería en Pesquerías, Universidad Autónoma de Baja California Sur, La Paz, BCS, Mexico
| | - Fred Sharpe
- McCowan Lab, University of California Davis, Davis, CA, USA
| | - Tasli Shaw
- Humpback Whales of the Salish Sea, Duncan, British Columbia, Canada
| | | | | | | | | | | | - Suzie Teerlink
- Juneau Flukes, Juneau, AK, USA
- NOAA Fisheries Alaska Regional Office, Juneau, AK, USA
| | - Olga Titova
- A. N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences, Moscow, Russia
| | | | - Martin van Aswegen
- Marine Mammal Research Program, Hawai'i Institute of Marine Biology, University of Hawai'i at Manoa, Kaneohe, HI, USA
| | | | | | - Briana Witteveen
- University of Alaska Fairbanks College of Fisheries and Ocean Sciences, Fairbanks, AK, USA
| | - Janie Wray
- North Coast Cetacean Society, Alert Bay, British Columbia, Canada
| | - Kymberly Yano
- NOAA Fisheries Pacific Islands Fisheries Science Center, Honolulu, HI, USA
- Cooperative Institute for Marine and Atmospheric Research, Research Corporation of the University of Hawai'i, Honolulu, HI, USA
| | - Igor Yegin
- Happywhale, Santa Cruz, CA, USA
- University of Stirling, Stirling, UK
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5
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Read AJ. The ecology of whales in a changing climate. Science 2023; 382:159-160. [PMID: 37824636 DOI: 10.1126/science.adk4244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2023]
Abstract
Some whale populations are exhibiting unexpected cycles of boom and bust.
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Affiliation(s)
- Andrew J Read
- Duke University Marine Laboratory, Nicholas School of the Environment, Duke University, Beaufort, NC, USA
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6
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Hallam J, Harris NC. What's going to be on the menu with global environmental changes? GLOBAL CHANGE BIOLOGY 2023; 29:5744-5759. [PMID: 37458101 DOI: 10.1111/gcb.16866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 05/13/2023] [Indexed: 07/18/2023]
Abstract
Ongoing anthropogenic change is altering the planet at an unprecedented rate, threatening biodiversity, and ecosystem functioning. Species are responding to abiotic pressures at both individual and population levels, with changes affecting trophic interactions through consumptive pathways. Collectively, these impacts alter the goods and services that natural ecosystems will provide to society, as well as the persistence of all species. Here, we describe the physiological and behavioral responses of species to global changes on individual and population levels that result in detectable changes in diet across terrestrial and marine ecosystems. We illustrate shifts in the dynamics of food webs with implications for animal communities. Additionally, we highlight the myriad of tools available for researchers to investigate the dynamics of consumption patterns and trophic interactions, arguing that diet data are a crucial component of ecological studies on global change. We suggest that a holistic approach integrating the complexities of diet choice and trophic interactions with environmental drivers may be more robust at resolving trends in biodiversity, predicting food web responses, and potentially identifying early warning signs of diversity loss. Ultimately, despite the growing body of long-term ecological datasets, there remains a dearth of diet ecology studies across temporal scales, a shortcoming that must be resolved to elucidate vulnerabilities to changing biophysical conditions.
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Affiliation(s)
- Jane Hallam
- Applied Wildlife Ecology Lab, Yale School of the Environment, Yale University, New Haven, Connecticut, USA
| | - Nyeema C Harris
- Applied Wildlife Ecology Lab, Yale School of the Environment, Yale University, New Haven, Connecticut, USA
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7
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Li P, Zhang H, Yang D, Gong C, Wu D, Sun Y, Liu Y, Tang J, Hu H, Zhaxi Q, Xu W, Su L, Li Y, Wu X. Vigilance behaviour during the calving season in female Tibetan antelopes ( Pantholopshodgsonii). Biodivers Data J 2023; 11:e107957. [PMID: 37711367 PMCID: PMC10498271 DOI: 10.3897/bdj.11.e107957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 08/22/2023] [Indexed: 09/16/2023] Open
Abstract
Tibetan antelopes (Pantholopshodgsonii) migrate great distances to specific delivery and calving areas. In the current study, we investigated calving site selection and vigilance behaviour during delivery and nursing in migratory female Tibetan antelopes at Zonag Lake. According to observations and analysis, the females were distributed south of Zonag Lake, where vegetation was abundant. We determined their dates of migration (crossing the Qinghai-Tibet Highway observation site), showing a shift of one month during the period from June in 2008 to May 2021. Results also showed that 81.4% of females expressed high vigilance behaviour during calving and nursing compared to those without calves (7.1%). From delivery until calf standing, females were highly vigilant and spent considerable time scanning, with 96% of females showing vigilance behaviour. Females with calves (average 9.94 ± 0.62 s) spent more time on vigilance behaviour than females without calves (average 6.25 ± 1.38 s). Females with newborns spent the greatest amount of time being vigilant (average 51.63 ± 4.24 s). These results not only identify basic Tibetan antelope calving behaviour, but also provide scientific analysis and evidence for further ethological research on female Tibetan antelopes.
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Affiliation(s)
- Peiwei Li
- Shaanxi Institute of Zoology, xi'an, ChinaShaanxi Institute of Zoologyxi'anChina
| | - Hongfeng Zhang
- Shaanxi Institute of Zoology, xi'an, ChinaShaanxi Institute of Zoologyxi'anChina
| | - Dongdong Yang
- Shaanxi Institute of Zoology, xi'an, ChinaShaanxi Institute of Zoologyxi'anChina
| | - Congran Gong
- Shaanxi Institute of Zoology, xi'an, ChinaShaanxi Institute of Zoologyxi'anChina
| | - Dong Wu
- Shaanxi Institute of Zoology, xi'an, ChinaShaanxi Institute of Zoologyxi'anChina
| | - Yuting Sun
- Shaanxi Institute of Zoology, xi'an, ChinaShaanxi Institute of Zoologyxi'anChina
| | - Yan Liu
- Shaanxi Institute of Zoology, xi'an, ChinaShaanxi Institute of Zoologyxi'anChina
| | - Junqing Tang
- School of Urban Planning and Design, Shenzhen Graduate School, Peking University, Shenzhen, ChinaSchool of Urban Planning and Design, Shenzhen Graduate School, Peking UniversityShenzhenChina
| | - Han Hu
- Shaanxi Institute of Zoology, xi'an, ChinaShaanxi Institute of Zoologyxi'anChina
| | - Qiupei Zhaxi
- Hoh Xil Nature Reserve service, Golmud, ChinaHoh Xil Nature Reserve serviceGolmudChina
| | - Wei Xu
- Three-River-Source National Park Service, Xining, ChinaThree-River-Source National Park ServiceXiningChina
| | - Lina Su
- Shaanxi Institute of Zoology, xi'an, ChinaShaanxi Institute of Zoologyxi'anChina
| | - Yinhu Li
- Shaanxi Institute of Zoology, xi'an, ChinaShaanxi Institute of Zoologyxi'anChina
| | - Xiaomin Wu
- Shaanxi Institute of Zoology, xi'an, ChinaShaanxi Institute of Zoologyxi'anChina
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8
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Fraleigh DC, Archer FI, Williard AS, Hückstädt LA, Fleming AH. Possible niche compression and individual specialization in Pacific Arctic beluga ( Delphinapterus leucas) from the 19th to 20th century. Ecol Evol 2023; 13:e10230. [PMID: 37408623 PMCID: PMC10318618 DOI: 10.1002/ece3.10230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 06/08/2023] [Accepted: 06/14/2023] [Indexed: 07/07/2023] Open
Abstract
Cetaceans have shown a potential to be used as sentinel species for tracking environmental change in marine ecosystems, yet our assessment of change is typically limited to recent decades and lacks ecological baselines. Using historical museum specimens, we compared community niche metrics and degree of individual dietary specialization in groups of Pacific Arctic beluga (Delphinapterus leucas) from the 1800s (n = 5) to 1900s (n = 10) using stable carbon and nitrogen isotopes drilled from teeth. Beluga occupied a broader trophic niche and demonstrated a higher degree of individual specialization in the 1800s than in the 1900s. The cause of this shift is difficult to confirm given long timescales and constraints of specimen-based research but could indicate changes in the prey base or competition. The scale and nature of this detected shift provide perspective for continued research on these climate-vulnerable species.
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Affiliation(s)
- Devin C. Fraleigh
- Center for Marine ScienceUniversity of North Carolina WilmingtonWilmingtonNorth CarolinaUSA
| | - Frederick I. Archer
- Southwest Fisheries Science CenterNational Marine Fisheries Service, National Oceanic and Atmospheric AdministrationLa JollaCaliforniaUSA
| | - Amanda S. Williard
- Department of Biology and Marine BiologyUniversity of North Carolina WilmingtonWilmingtonNorth CarolinaUSA
| | - Luis A. Hückstädt
- Department of Biology and Marine BiologyUniversity of North Carolina WilmingtonWilmingtonNorth CarolinaUSA
- Centre for Ecology and ConservationUniversity of ExeterCornwallUK
| | - Alyson H. Fleming
- Center for Marine ScienceUniversity of North Carolina WilmingtonWilmingtonNorth CarolinaUSA
- Department of Forest & Wildlife EcologyUniversity of Wisconsin‐MadisonMadisonWisconsinUSA
- National Museum of Natural HistorySmithsonian InstitutionWashingtonDistrict of ColumbiaUSA
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9
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Pallin LJ, Kellar NM, Steel D, Botero-Acosta N, Baker CS, Conroy JA, Costa DP, Johnson CM, Johnston DW, Nichols RC, Nowacek DP, Read AJ, Savenko O, Schofield OM, Stammerjohn SE, Steinberg DK, Friedlaender AS. A surplus no more? Variation in krill availability impacts reproductive rates of Antarctic baleen whales. GLOBAL CHANGE BIOLOGY 2023; 29:2108-2121. [PMID: 36644792 DOI: 10.1111/gcb.16559] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 12/01/2022] [Indexed: 05/28/2023]
Abstract
The krill surplus hypothesis of unlimited prey resources available for Antarctic predators due to commercial whaling in the 20th century has remained largely untested since the 1970s. Rapid warming of the Western Antarctic Peninsula (WAP) over the past 50 years has resulted in decreased seasonal ice cover and a reduction of krill. The latter is being exacerbated by a commercial krill fishery in the region. Despite this, humpback whale populations have increased but may be at a threshold for growth based on these human-induced changes. Understanding how climate-mediated variation in prey availability influences humpback whale population dynamics is critical for focused management and conservation actions. Using an 8-year dataset (2013-2020), we show that inter-annual humpback whale pregnancy rates, as determined from skin-blubber biopsy samples (n = 616), are positively correlated with krill availability and fluctuations in ice cover in the previous year. Pregnancy rates showed significant inter-annual variability, between 29% and 86%. Our results indicate that krill availability is in fact limiting and affecting reproductive rates, in contrast to the krill surplus hypothesis. This suggests that this population of humpback whales may be at a threshold for population growth due to prey limitations. As a result, continued warming and increased fishing along the WAP, which continue to reduce krill stocks, will likely impact this humpback whale population and other krill predators in the region. Humpback whales are sentinel species of ecosystem health, and changes in pregnancy rates can provide quantifiable signals of the impact of environmental change at the population level. Our findings must be considered paramount in developing new and more restrictive conservation and management plans for the Antarctic marine ecosystem and minimizing the negative impacts of human activities in the region.
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Affiliation(s)
- Logan J Pallin
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, California, USA
| | - Nick M Kellar
- Marine Mammal and Turtle Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, La Jolla, California, USA
| | - Debbie Steel
- Department of Fisheries, Wildlife & Conservation Sciences, Marine Mammal Institute, Oregon State University, Hatfield Marine Science Center, Newport, Oregon, USA
| | - Natalia Botero-Acosta
- Fundación Macuáticos Colombia, Medellín, Colombia
- Programa Antártico Colombiano, Edificio World Business Center - WBC, Bogotá, Colombia
| | - C Scott Baker
- Department of Fisheries, Wildlife & Conservation Sciences, Marine Mammal Institute, Oregon State University, Hatfield Marine Science Center, Newport, Oregon, USA
| | - Jack A Conroy
- Virginia Institute of Marine Science, William & Mary, Gloucester Point, Virginia, USA
| | - Daniel P Costa
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, California, USA
| | - Chris M Johnson
- World Wide Fund for Nature (WWF), Melbourne, Australia
- Centre for Marine Science & Technology, Curtin University, Perth, Australia
| | - David W Johnston
- Division of Marine Science and Conservation, Nicholas School of the Environment, Duke University Marine Laboratory, Beaufort, North Carolina, USA
| | - Ross C Nichols
- Institute for Marine Science, University of California Santa Cruz, Santa Cruz, California, USA
| | - Doug P Nowacek
- Division of Marine Science and Conservation, Nicholas School of the Environment, Duke University Marine Laboratory, Beaufort, North Carolina, USA
| | - Andrew J Read
- Division of Marine Science and Conservation, Nicholas School of the Environment, Duke University Marine Laboratory, Beaufort, North Carolina, USA
| | - Oksana Savenko
- National Antarctic Scientific Center of Ukraine, Kyiv, Ukraine
- Ukrainian Scientific Center of Ecology of the Sea, Odesa, Ukraine
| | - Oscar M Schofield
- Center of Ocean Observing Leadership, Rutgers University, New Brunswick, New Jersey, USA
| | - Sharon E Stammerjohn
- Institute of Arctic and Alpine Research, University of Colorado, Boulder, Colorado, USA
| | - Deborah K Steinberg
- Virginia Institute of Marine Science, William & Mary, Gloucester Point, Virginia, USA
| | - Ari S Friedlaender
- Institute for Marine Science, University of California Santa Cruz, Santa Cruz, California, USA
- Department of Ocean Sciences, University of California Santa Cruz, Santa Cruz, California, USA
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10
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Cerini F, Childs DZ, Clements CF. A predictive timeline of wildlife population collapse. Nat Ecol Evol 2023; 7:320-331. [PMID: 36702859 DOI: 10.1038/s41559-023-01985-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 01/06/2023] [Indexed: 01/27/2023]
Abstract
Contemporary rates of biodiversity decline emphasize the need for reliable ecological forecasting, but current methods vary in their ability to predict the declines of real-world populations. Acknowledging that stressor effects start at the individual level, and that it is the sum of these individual-level effects that drives populations to collapse, shifts the focus of predictive ecology away from using predominantly abundance data. Doing so opens new opportunities to develop predictive frameworks that utilize increasingly available multi-dimensional data, which have previously been overlooked for ecological forecasting. Here, we propose that stressed populations will exhibit a predictable sequence of observable changes through time: changes in individuals' behaviour will occur as the first sign of increasing stress, followed by changes in fitness-related morphological traits, shifts in the dynamics (for example, birth rates) of populations and finally abundance declines. We discuss how monitoring the sequential appearance of these signals may allow us to discern whether a population is increasingly at risk of collapse, or is adapting in the face of environmental change, providing a conceptual framework to develop new forecasting methods that combine multi-dimensional (for example, behaviour, morphology, life history and abundance) data.
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Affiliation(s)
- Francesco Cerini
- School of Biological Sciences, University of Bristol, Bristol, UK.
| | - Dylan Z Childs
- School of Biosciences, University of Sheffield, Sheffield, UK
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11
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Szesciorka AR, Demer DA, Santora JA, Forney KA, Moore JE. Multiscale relationships between humpback whales and forage species hotspots within a large marine ecosystem. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2023; 33:e2794. [PMID: 36484787 DOI: 10.1002/eap.2794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 09/22/2022] [Accepted: 09/27/2022] [Indexed: 06/17/2023]
Abstract
Fluctuations in prey abundance, composition, and distribution can impact predators, and when predators and fisheries target the same species, predators become essential to ecosystem-based management. Because of the difficulty in collecting concomitant predator-prey data at appropriate scales in patchy environments, few studies have identified strong linkages between cetaceans and prey, especially across large geographic areas. During summer 2018, a line-transect survey for cetaceans and coastal pelagic species was conducted over the continental shelf and slope of British Columbia, Canada, and the US West Coast, allowing for a large-scale investigation of predator-prey spatial relationships. We report on a case study of humpback whales (Megaptera novaeangliae) and their primary prey-Pacific herring (Clupea pallasii), northern anchovy (Engraulis mordax), and krill-using generalized additive models to explore the relationships between whale abundance on 10-km transect segments and prey metrics. Prey metrics included direct measures of biomass densities on segments and an original hotspot metric. For each prey species, segments in the upper fifth percentile for biomass density (across all segments) were designated hotspots, and whale counts on a segment were evaluated for their relationship to number of hotspot segments (species-specific and multispecies) within 25, 50, or 100 km. Whale abundance was not strongly related to direct measures of biomass densities, whereas models using hotspot metrics were more effective at describing variation in whale abundance, underscoring that evaluating prey at relevant and measurable scales is critical in patchy, dynamic marine environments. Our analysis highlighted differences in the distribution and prey availability for three humpback whale distinct population segments (DPSs) as defined under the US Endangered Species Act, including threatened and endangered DPSs that forage within the California Current Large Marine Ecosystem. These linkages provide insights into which prey species whales may be targeting in different regions and across multiple scales and, consequently, how climatic variability and anthropogenic risks may differentially impact these distinct predator-prey assemblages. By identifying scale-appropriate prey hotspots that co-occur with humpback whale aggregations, and with targeted, consistent prey sampling and estimations of potential consumption rates by whales, these findings can help inform the conservation and management of humpback whales within an ecosystem-based management framework.
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Affiliation(s)
- Angela R Szesciorka
- Environmental Assessment Services, LLC. Under Contract to NOAA Southwest Fisheries Science Center, Richland, Washington, USA
- Marine Mammal Institute, Hatfield Marine Science Center, Oregon State University, Newport, Oregon, USA
| | - David A Demer
- Fisheries Resources Division, Southwest Fisheries Science Center, NOAA, La Jolla, California, USA
| | - Jarrod A Santora
- Fisheries Ecology Division, Southwest Fisheries Science Center, NOAA, La Jolla, California, USA
- Department of Applied Math, University of California Santa Cruz, Santa Cruz, California, USA
| | - Karin A Forney
- Marine Mammal and Turtle Division, Southwest Fisheries Science Center, NOAA, Moss Landing, California, USA
- Moss Landing Marine Laboratories, San Jose State University, Moss Landing, California, USA
| | - Jeff E Moore
- Marine Mammal and Turtle Division, Southwest Fisheries Science Center, NOAA, La Jolla, California, USA
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12
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Reidy R, Gauthier S, Doniol-Valcroze T, Lemay MA, Clemente-Carvalho RBG, Cowen LLE, Juanes F. Integrating technologies provides insight into the subsurface foraging behaviour of a humpback whale (Megaptera novaeangliae) feeding on walleye pollock (Gadus chalcogrammus) in Juan de Fuca Strait, Canada. PLoS One 2023; 18:e0282651. [PMID: 36877706 PMCID: PMC9987809 DOI: 10.1371/journal.pone.0282651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Accepted: 02/19/2023] [Indexed: 03/07/2023] Open
Abstract
Subsurface foraging is an important proportion of the activity budget of rorqual whales, yet information on their behaviour underwater remains challenging to obtain. Rorquals are assumed to feed throughout the water column and to select prey as a function of depth, availability and density, but there remain limitations in the precise identification of targeted prey. Current data on rorqual foraging in western Canadian waters have thus been limited to observations of prey species amenable to surface feeding, such as euphausiids and Pacific herring (Clupea pallasii), with no information on deeper alternative prey sources. We measured the foraging behaviour of a humpback whale (Megaptera novaeangliae) in Juan de Fuca Strait, British Columbia, using three complimentary methods: whale-borne tag data, acoustic prey mapping, and fecal sub-sampling. Acoustically detected prey layers were near the seafloor and consistent with dense schools of walleye pollock (Gadus chalcogrammus) distributed above more diffuse aggregations of pollock. Analysis of a fecal sample from the tagged whale confirmed that it had been feeding on pollock. Integrating the dive profile with the prey data revealed that the whale's foraging effort followed the general pattern of areal prey density, wherein the whale had a higher lunge-feeding rate at the highest prey abundance and stopped feeding when prey became limited. Our findings of a humpback whale feeding on seasonally energy-dense fish like walleye pollock, which are potentially abundant in British Columbia, suggests that pollock may be an important prey source for this rapidly growing whale population. This result is informative when assessing regional fishing activities for semi-pelagic species as well as the whales' vulnerability to fishing gear entanglements and feeding disturbances during a narrow window of prey acquisition.
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Affiliation(s)
- Rhonda Reidy
- Department of Biology, University of Victoria, Victoria, British Columbia, Canada
- * E-mail:
| | - Stéphane Gauthier
- Department of Biology, University of Victoria, Victoria, British Columbia, Canada
- Institute of Ocean Sciences, Fisheries and Oceans Canada, Sidney, British Columbia, Canada
| | - Thomas Doniol-Valcroze
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, British Columbia, Canada
| | - Matthew A. Lemay
- Hakai Institute Genomics Laboratory, Quadra Island, British Columbia, Canada
| | | | - Laura L. E. Cowen
- Department of Mathematics and Statistics, University of Victoria, Victoria, British Columbia, Canada
| | - Francis Juanes
- Department of Biology, University of Victoria, Victoria, British Columbia, Canada
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13
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Reidy RD, Lemay MA, Innes KG, Clemente‐Carvalho RBG, Janusson C, Dower JF, Cowen LLE, Juanes F. Fine-scale diversity of prey detected in humpback whale feces. Ecol Evol 2022; 12:e9680. [PMID: 36619710 PMCID: PMC9797768 DOI: 10.1002/ece3.9680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Revised: 12/09/2022] [Accepted: 12/10/2022] [Indexed: 12/30/2022] Open
Abstract
Predator diets are largely influenced by prey availability and abundance. Yet, in heterogenous marine environments, identifying the prey species consumed by diving mammals remains a fundamental challenge. For rorqual whales, the energetic constraints of prey engulfment require that the whales seek areas of high prey abundance and execute discrete lunge feeding events on patches of high-density prey. Prey occurrences in feces should therefore provide meaningful insight into the dominant taxa in food patches selected by the animal. We investigated the prey consumed by humpback whales in three regions in southern British Columbia (BC), Canada, using opportunistic fecal sampling, microscopy, and DNA metabarcoding of 14 fecal samples. Fish including Pacific herring (Clupea pallasii), hake (Merluccius productus), and eulachon (Thaleichthys pacificus) were the most common fish species potentially targeted by humpback whales in two regions. The krill Euphausia pacifica was the most prevalent invertebrate DNA detected in all three regions, while sergestid and mysid shrimp may also be important. High DNA read abundances from walleye pollock (Gadus chalcogrammus) and sablefish (Anoplopoma fimbria) were also recovered in one sample each, suggesting that juveniles of these semi-pelagic species may occasionally be targeted. In general, we observed heavily digested fecal material that drove substantial dissimilarities in taxonomic resolution between polymerase chain reaction-based and morphological analyses of the feces. Pacific herring and walleye pollock were the only prey species confirmed by both methods. Our results highlight that molecular and visual analyses of fecal samples provide a complementary approach to diet analysis, with each method providing unique insight into prey diversity.
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Affiliation(s)
- Rhonda D. Reidy
- Department of BiologyUniversity of VictoriaVictoriaBritish ColumbiaCanada
| | - Matthew A. Lemay
- Hakai Institute Genomics LaboratoryQuadra IslandBritish ColumbiaCanada
| | - Katie G. Innes
- Department of BiologyUniversity of VictoriaVictoriaBritish ColumbiaCanada
| | | | - Carly Janusson
- Hakai Institute Genomics LaboratoryQuadra IslandBritish ColumbiaCanada
| | - John F. Dower
- Department of BiologyUniversity of VictoriaVictoriaBritish ColumbiaCanada
| | - Laura L. E. Cowen
- Department of Mathematics and StatisticsUniversity of VictoriaVictoriaBritish ColumbiaCanada
| | - Francis Juanes
- Department of BiologyUniversity of VictoriaVictoriaBritish ColumbiaCanada
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14
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Field measurements reveal exposure risk to microplastic ingestion by filter-feeding megafauna. Nat Commun 2022; 13:6327. [PMID: 36319629 PMCID: PMC9626449 DOI: 10.1038/s41467-022-33334-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 09/13/2022] [Indexed: 11/08/2022] Open
Abstract
Microparticles, such as microplastics and microfibers, are ubiquitous in marine food webs. Filter-feeding megafauna may be at extreme risk of exposure to microplastics, but neither the amount nor pathway of microplastic ingestion are well understood. Here, we combine depth-integrated microplastic data from the California Current Ecosystem with high-resolution foraging measurements from 191 tag deployments on blue, fin, and humpback whales to quantify plastic ingestion rates and routes of exposure. We find that baleen whales predominantly feed at depths of 50-250 m, coinciding with the highest measured microplastic concentrations in the pelagic ecosystem. Nearly all (99%) microplastic ingestion is predicted to occur via trophic transfer. We predict that fish-feeding whales are less exposed to microplastic ingestion than krill-feeding whales. Per day, a krill-obligate blue whale may ingest 10 million pieces of microplastic, while a fish-feeding humpback whale likely ingests 200,000 pieces of microplastic. For species struggling to recover from historical whaling alongside other anthropogenic pressures, our findings suggest that the cumulative impacts of multiple stressors require further attention.
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15
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Carroll EL, Riekkola L, Andrews-Goff V, Baker CS, Constantine R, Cole R, Goetz K, Harcourt R, Lundquist D, Meyer C, Ogle M, O’Rorke R, Patenaude N, Russ R, Stuck E, van der Reis AL, Zerbini AN, Childerhouse S. New Zealand southern right whale (Eubalaena australis; Tohorā nō Aotearoa) behavioural phenology, demographic composition, and habitat use in Port Ross, Auckland Islands over three decades: 1998–2021. Polar Biol 2022. [DOI: 10.1007/s00300-022-03076-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AbstractChanges in habitat availability and prey abundance are predicted to adversely influence survival and reproduction of wildlife in the Southern Ocean. Some populations of southern right whale (SRW; Eubalaena australis) are showing dramatic changes in habitat use. Surveys were undertaken in the austral winters of 2020 and 2021 at the key nursery and socialising ground for New Zealand SRWs: Port Ross, Auckland Islands, with 548 encounters and 599 skin biopsy samples collected. Data from these two surveys spanned peak periods of use and were used to test the hypothesis there have been shifts in the phenology, demographic composition and behaviour of SRWs using the Auckland Islands over the past three decades. The behavioural phenology and demographic composition of SRW resembles that observed in the 1990s. In contrast, the proportion of groups containing cow-calf pairs increased from 20% in the 1998 survey to 50% in 2020/21. These changes are consistent with a growing population undergoing strong recruitment, not limited by food resources. Continued use of Port Ross by all SRW demographic classes confirms this as key habitat for SRW in New Zealand waters, and we support increased enforcement of existing management measures to reduce whale-vessel interactions in this remote subantarctic archipelago.
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16
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Turner Tomaszewicz CN, Liles MJ, Avens L, Seminoff JA. Tracking movements and growth of post-hatchling to adult hawksbill sea turtles using skeleto+iso. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.983260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
In the eastern Pacific Ocean, hawksbill sea turtles (Eretmochelys imbricata) are adapted to use coastal habitats and ecosystems uncharacteristic of most other sea turtles. Once considered extirpated from this region, hawksbills had sought refuge in estuaries, nesting on muddy banks among the tangles of mangrove roots. This population is at high risk of bycatch during fishing efforts in the estuaries (blast fishing) and adjacent coastal rocky reefs (gillnets), and is further impacted by habitat degradation from coastal development and climate change. The conservation and population recovery of hawksbills in this region is highly dependent on management actions (e.g., nest relocation, habitat protection, bycatch mitigation), and a better understanding of how hawksbills use and move between distinct habitats will help prioritize conservation efforts. To identify multi-year habitat use and movement patterns, we used stable carbon (δ13C) and nitrogen (δ15N) isotope analysis of skin and bone growth layers to recreate movements between two isotopically distinct habitats, a nearshore rocky reef and a mangrove estuary, the latter distinguishable by low δ13C and δ15N values characteristic of a mangrove-based foodweb. We applied skeletochronology with sequential δ13C and δ15N analysis of annual growth layers, “skeleto+iso,” to a dataset of 70 hawksbill humeri collected from coastal El Salvador. The results revealed at least two unique habitat-use patterns. All turtles, regardless of stranding location, spent time outside of the mangrove estuaries during their early juvenile years (< 35 cm curved carapace length, CCL, age 0–5), showing that an oceanic juvenile stage is likely for this population. Juveniles ca. > 35 cm then began to recruit to nearshore areas, but showed divergent habitat-use as some of turtles occupied the coastal rocky reefs, while others settled into the mangrove estuaries. For turtles recruiting to the estuaries, settlement age and size ranged from 3 to 13 years and 35–65 cm CCL. For the adult turtles, age-at-sexual-maturity ranged from 16 to 26 years, and the maximum reproductive longevity observed was 33 years. The skeleto+iso also showed that adult hawksbills have long-term habitat fidelity, and the results demonstrate the importance of both mangrove estuary and nearshore rocky reefs to the conservation of hawksbills in the eastern Pacific.
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17
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Ogilvy C, Constantine R, Bury SJ, Carroll EL. Diet variation in a critically endangered marine predator revealed with stable isotope analysis. ROYAL SOCIETY OPEN SCIENCE 2022; 9:220470. [PMID: 35991335 PMCID: PMC9382206 DOI: 10.1098/rsos.220470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Accepted: 07/20/2022] [Indexed: 06/15/2023]
Abstract
Understanding the foraging ecology of animals gives insights into their trophic relationships and habitat use. We used stable isotope analysis to understand the foraging ecology of a critically endangered marine predator, the Māui dolphin. We analysed carbon and nitrogen isotope ratios of skin samples (n = 101) collected from 1993 to 2021 to investigate temporal changes in diet and niche space. Genetic monitoring associated each sample with a DNA profile which allowed us to assess individual and population level changes in diet. Potential prey and trophic level indicator samples were also collected (n = 166; 15 species) and incorporated in Bayesian mixing models to estimate importance of prey types to Māui dolphin diet. We found isotopic niche space had decreased over time, particularly since the 2008 implementation of a Marine Mammal Sanctuary. We observed a decreasing trend in ∂13C and ∂15N values, but this was not linear and several fluctuations in isotope values occurred over time. The largest variation in isotope values occurred during an El Niño event, suggesting that prey is influenced by climate-driven oceanographic variables. Mixing models indicated relative importance of prey remained constant since 2008. The isotopic variability observed here is not consistent with individual specialization, rather it occurs at the population level.
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Affiliation(s)
- Courtney Ogilvy
- School of Biological Sciences, University of Auckland, Auckland 1010, New Zealand
| | - Rochelle Constantine
- School of Biological Sciences, University of Auckland, Auckland 1010, New Zealand
- Institute of Marine Science, University of Auckland, Auckland 1010, New Zealand
| | - Sarah J. Bury
- National Institute of Water and Atmospheric Research, Greta Point, Wellington 6021, New Zealand
| | - Emma L. Carroll
- School of Biological Sciences, University of Auckland, Auckland 1010, New Zealand
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18
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Bedriñana-Romano L, Zerbini AN, Andriolo A, Danilewicz D, Sucunza F. Individual and joint estimation of humpback whale migratory patterns and their environmental drivers in the Southwest Atlantic Ocean. Sci Rep 2022; 12:7487. [PMID: 35523932 PMCID: PMC9076679 DOI: 10.1038/s41598-022-11536-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 04/18/2022] [Indexed: 02/05/2023] Open
Abstract
Humpback whales (Megaptera novaeangliae) perform seasonal migrations from high latitude feeding grounds to low latitude breeding and calving grounds. Feeding grounds at polar regions are currently experiencing major ecosystem modifications, therefore, quantitatively assessing species responses to habitat characteristics is crucial for understanding how whales might respond to such modifications. We analyzed satellite telemetry data from 22 individual humpback whales in the Southwest Atlantic Ocean (SWA). Tagging effort was divided in two periods, 2003-2012 and 2016-2019. Correlations between whale's movement parameters and environmental variables were used as proxy for inferring behavioral responses to environmental variation. Two versions of a covariate-driven continuous-time correlated random-walk state-space model, were fitted to the data: i) Population-level models (P-models), which assess correlation parameters pooling data across all individuals or groups, and ii) individual-level models (I-models), fitted independently for each tagged whale. Area of Restricted Search behavior (slower and less directionally persistent movement, ARS) was concentrated at cold waters south of the Polar Front (~ 50°S). The best model showed that ARS was expected to occur in coastal areas and over ridges and seamounts. Ice coverage during August of each year was a consistent predictor of ARS across models. Wind stress curl and sea surface temperature anomalies were also correlated with movement parameters but elicited larger inter-individual variation. I-models were consistent with P-models' predictions for the case of females accompanied by calves (mothers), while males and those of undetermined sex (males +) presented more variability as a group. Spatial predictions of humpback whale behavioral responses showed that feeding grounds for this population are concentrated in the complex system of islands, ridges, and rises of the Scotia Sea and the northern Weddell Ridge. More southernly incursions were observed in recent years, suggesting a potential response to increased temperature and large ice coverage reduction observed in the late 2010s. Although, small sample size and differences in tracking duration precluded appropriately testing predictions for such a distributional shift, our modelling framework showed the efficiency of borrowing statistical strength during data pooling, while pinpointing where more complexity should be added in the future as additional data become available.
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Affiliation(s)
- Luis Bedriñana-Romano
- Instituto de Ciencias Marinas y Limnológicas, Facultad de Ciencias, Universidad Austral de Chile, Casilla 567, Valdivia, Chile. .,NGO Centro Ballena Azul, Valdivia, Chile. .,Centro de Investigación Oceanográfica COPAS Coastal, Universidad de Concepción, Región del Bio Bio, 4070043, Concepción, Chile.
| | - Alexandre N Zerbini
- Cooperative Institute for Climate, Ocean and Ecosystem Studies, University of Washington and Marine Mammal Laboratory Alaska Fisheries Science Center/NOAA, 7600 Sand Point Way NE, Seattle, WA, USA.,Marine Ecology and Telemetry Research, 2468 Camp McKenzie Tr NW, Seabeck, WA, 98380, USA.,Instituto Aqualie, Av. Dr. Paulo Japiassú Coelho, 714, Sala 206, Juiz de Fora, MG, 36033-310, Brazil
| | - Artur Andriolo
- Instituto Aqualie, Av. Dr. Paulo Japiassú Coelho, 714, Sala 206, Juiz de Fora, MG, 36033-310, Brazil.,Laboratório de Ecologia Comportamental e Bioacústica, LABEC, Departamento de Zoologia, Instituto de Ciências Biológicas, Universidade Federal de Juiz de Fora, Juiz de Fora, Minas Gerais, Brazil
| | - Daniel Danilewicz
- Instituto Aqualie, Av. Dr. Paulo Japiassú Coelho, 714, Sala 206, Juiz de Fora, MG, 36033-310, Brazil.,Grupo de Estudos de Mamíferos Aquáticos do Rio Grande do Sul (GEMARS), Porto Alegre, RS, Brazil
| | - Federico Sucunza
- Instituto Aqualie, Av. Dr. Paulo Japiassú Coelho, 714, Sala 206, Juiz de Fora, MG, 36033-310, Brazil.,Grupo de Estudos de Mamíferos Aquáticos do Rio Grande do Sul (GEMARS), Porto Alegre, RS, Brazil
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19
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Cabrera AA, Schall E, Bérubé M, Anderwald P, Bachmann L, Berrow S, Best PB, Clapham PJ, Cunha H, Dalla Rosa L, Dias C, Findlay K, Haug T, Heide‐Jørgensen MP, Hoelzel A, Kovacs KM, Landry S, Larsen F, Lopes XM, Lydersen C, Mattila DK, Oosting T, Pace RM, Papetti C, Paspati A, Pastene LA, Prieto R, Ramp C, Robbins J, Sears R, Secchi ER, Silva MA, Simon M, Víkingsson G, Wiig Ø, Øien N, Palsbøll PJ. Strong and lasting impacts of past global warming on baleen whales and their prey. GLOBAL CHANGE BIOLOGY 2022; 28:2657-2677. [PMID: 35106859 PMCID: PMC9305191 DOI: 10.1111/gcb.16085] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 11/01/2021] [Accepted: 11/03/2021] [Indexed: 05/14/2023]
Abstract
Global warming is affecting the population dynamics and trophic interactions across a wide range of ecosystems and habitats. Translating these real-time effects into their long-term consequences remains a challenge. The rapid and extreme warming period that occurred after the Last Glacial Maximum (LGM) during the Pleistocene-Holocene transition (7-12 thousand years ago) provides an opportunity to gain insights into the long-term responses of natural populations to periods with global warming. The effects of this post-LGM warming period have been assessed in many terrestrial taxa, whereas insights into the impacts of rapid global warming on marine taxa remain limited, especially for megafauna. In order to understand how large-scale climate fluctuations during the post-LGM affected baleen whales and their prey, we conducted an extensive, large-scale analysis of the long-term effects of the post-LGM warming on abundance and inter-ocean connectivity in eight baleen whale and seven prey (fish and invertebrates) species across the Southern and the North Atlantic Ocean; two ocean basins that differ in key oceanographic features. The analysis was based upon 7032 mitochondrial DNA sequences as well as genome-wide DNA sequence variation in 100 individuals. The estimated temporal changes in genetic diversity during the last 30,000 years indicated that most baleen whale populations underwent post-LGM expansions in both ocean basins. The increase in baleen whale abundance during the Holocene was associated with simultaneous changes in their prey and climate. Highly correlated, synchronized and exponential increases in abundance in both baleen whales and their prey in the Southern Ocean were indicative of a dramatic increase in ocean productivity. In contrast, the demographic fluctuations observed in baleen whales and their prey in the North Atlantic Ocean were subtle, varying across taxa and time. Perhaps most important was the observation that the ocean-wide expansions and decreases in abundance that were initiated by the post-LGM global warming, continued for millennia after global temperatures stabilized, reflecting persistent, long-lasting impacts of global warming on marine fauna.
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Affiliation(s)
- Andrea A. Cabrera
- Groningen Institute for Evolutionary Life SciencesUniversity of GroningenGroningenThe Netherlands
- GLOBE InstituteUniversity of CopenhagenCopenhagenDenmark
| | - Elena Schall
- Groningen Institute for Evolutionary Life SciencesUniversity of GroningenGroningenThe Netherlands
| | - Martine Bérubé
- Groningen Institute for Evolutionary Life SciencesUniversity of GroningenGroningenThe Netherlands
- Center for Coastal StudiesProvincetownMassachusettsUSA
| | - Pia Anderwald
- Swiss National ParkChastè Planta‐WildenbergZernezSwitzerland
| | | | - Simon Berrow
- Marine and Freshwater Research CentreGalway‐Mayo Institute of TechnologyGalwayIreland
- Irish Whale and Dolphin GroupMerchants QuayKilrushCounty ClareIreland
| | - Peter B. Best
- Department of Zoology and EntomologyMammal Research InstituteUniversity of PretoriaHatfieldSouth Africa
| | | | - Haydée A. Cunha
- Aquatic Mammals and Bioindicators Laboratory (MAQUA)Faculty of OceanographyState University of Rio de Janeiro ‐ UERJMaracanãRio de JaneiroBrazil
- Genetics Department of the Biology InstituteState University of Rio de Janeiro ‐ UERJMaracanãRio de JaneiroBrazil
| | - Luciano Dalla Rosa
- Laboratory of Ecology and Conservation of Marine MegafaunaInstitute of OceanographyFederal University of Rio Grande‐FURGRio GrandeRio Grande do SulBrazil
| | - Carolina Dias
- Aquatic Mammals and Bioindicators Laboratory (MAQUA)Faculty of OceanographyState University of Rio de Janeiro ‐ UERJMaracanãRio de JaneiroBrazil
| | - Kenneth P. Findlay
- Department of Zoology and EntomologyMammal Research InstituteUniversity of PretoriaHatfieldSouth Africa
- Department Conservation and Marine SciencesCentre for Sustainable Oceans EconomyCape Peninsula University of TechnologyCape TownSouth Africa
| | - Tore Haug
- Research Group Marine MammalsInstitute of Marine ResearchTromsøNorway
| | | | | | | | - Scott Landry
- Center for Coastal StudiesProvincetownMassachusettsUSA
| | - Finn Larsen
- Section for Ecosystem based Marine ManagementNational Institute of Aquatic ResourcesTechnical University of DenmarkKongens LyngbyDenmark
| | - Xênia M. Lopes
- Groningen Institute for Evolutionary Life SciencesUniversity of GroningenGroningenThe Netherlands
| | | | | | - Tom Oosting
- Groningen Institute for Evolutionary Life SciencesUniversity of GroningenGroningenThe Netherlands
- School of Biological SciencesVictoria University of WellingtonWellingtonNew Zealand
| | - Richard M. Pace
- Northeast Fisheries Science CenterNational Marine Fisheries ServiceWoods HoleMassachusettsUSA
| | | | - Angeliki Paspati
- Groningen Institute for Evolutionary Life SciencesUniversity of GroningenGroningenThe Netherlands
- Hellenic Agricultural Organisation‐“DIMITRA”HerakleionCreteGreece
| | | | - Rui Prieto
- Institute of Marine Sciences – Okeanos & Institute of Marine Research ‐ IMARUniversity of the AzoresHortaPortugal
| | - Christian Ramp
- Sea Mammal Research UnitScottish Oceans InstituteUniversity of St. AndrewsScotlandUK
- Mingan Island Cetacean StudySaint LambertQuébecCanada
| | - Jooke Robbins
- Center for Coastal StudiesProvincetownMassachusettsUSA
| | - Richard Sears
- Greenland Climate Research CentreGreenland Institute of Natural ResourcesNuukGreenland
| | - Eduardo R. Secchi
- Laboratory of Ecology and Conservation of Marine MegafaunaInstitute of OceanographyFederal University of Rio Grande‐FURGRio GrandeRio Grande do SulBrazil
| | - Mónica A. Silva
- Institute of Marine Sciences – Okeanos & Institute of Marine Research ‐ IMARUniversity of the AzoresHortaPortugal
| | - Malene Simon
- Greenland Climate Research CentreGreenland Institute of Natural ResourcesNuukGreenland
| | | | - Øystein Wiig
- Natural History MuseumUniversity of OsloOsloNorway
| | - Nils Øien
- Marine Mammal DivisionInstitute of Marine ResearchBergenNorway
| | - Per J. Palsbøll
- Groningen Institute for Evolutionary Life SciencesUniversity of GroningenGroningenThe Netherlands
- Center for Coastal StudiesProvincetownMassachusettsUSA
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20
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Burford BP, Williams RR, Demetras NJ, Carey N, Goldbogen J, Gilly WF, Harding J, Denny MW. The limits of convergence in the collective behavior of competing marine taxa. Ecol Evol 2022; 12:e8747. [PMID: 35356556 PMCID: PMC8939367 DOI: 10.1002/ece3.8747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 01/31/2022] [Accepted: 02/24/2022] [Indexed: 11/23/2022] Open
Abstract
Collective behaviors in biological systems such as coordinated movements have important ecological and evolutionary consequences. While many studies examine within‐species variation in collective behavior, explicit comparisons between functionally similar species from different taxonomic groups are rare. Therefore, a fundamental question remains: how do collective behaviors compare between taxa with morphological and physiological convergence, and how might this relate to functional ecology and niche partitioning? We examined the collective motion of two ecologically similar species from unrelated clades that have competed for pelagic predatory niches for over 500 million years—California market squid, Doryteuthis opalescens (Mollusca) and Pacific sardine, Sardinops sagax (Chordata). We (1) found similarities in how groups of individuals from each species collectively aligned, measured by angular deviation, the difference between individual orientation and average group heading. We also (2) show that conspecific attraction, which we approximated using nearest neighbor distance, was greater in sardine than squid. Finally, we (3) found that individuals of each species explicitly matched the orientation of groupmates, but that these matching responses were less rapid in squid than sardine. Based on these results, we hypothesize that information sharing is a comparably important function of social grouping for both taxa. On the other hand, some capabilities, including hydrodynamically conferred energy savings and defense against predators, could stem from taxon‐specific biology.
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Affiliation(s)
- Benjamin P. Burford
- Hopkins Marine Station of Stanford University Pacific Grove California USA
- Institute of Marine Sciences, affiliated with the National Oceanic and Atmospheric Administration National Marine Fisheries Service Southwest Fisheries Science Center University of California Santa Cruz Santa Cruz California USA
| | | | - Nicholas J. Demetras
- Institute of Marine Sciences, affiliated with the National Oceanic and Atmospheric Administration National Marine Fisheries Service Southwest Fisheries Science Center University of California Santa Cruz Santa Cruz California USA
| | - Nicholas Carey
- Hopkins Marine Station of Stanford University Pacific Grove California USA
- Marine Scotland Science Aberdeen UK
| | - Jeremy Goldbogen
- Hopkins Marine Station of Stanford University Pacific Grove California USA
| | - William F. Gilly
- Hopkins Marine Station of Stanford University Pacific Grove California USA
| | - Jeffrey Harding
- National Oceanic and Atmospheric Administration National Marine Fisheries Service Southwest Fisheries Science Center Santa Cruz California USA
| | - Mark W. Denny
- Hopkins Marine Station of Stanford University Pacific Grove California USA
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21
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Sharp decline in humpback whale (Megaptera novaeangliae) survival and reproductive success in southeastern Alaska during and after the 2014–2016 Northeast Pacific marine heatwave. Mamm Biol 2022. [DOI: 10.1007/s42991-021-00187-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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22
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Savoca MS, Czapanskiy MF, Kahane-Rapport SR, Gough WT, Fahlbusch JA, Bierlich KC, Segre PS, Di Clemente J, Penry GS, Wiley DN, Calambokidis J, Nowacek DP, Johnston DW, Pyenson ND, Friedlaender AS, Hazen EL, Goldbogen JA. Baleen whale prey consumption based on high-resolution foraging measurements. Nature 2021; 599:85-90. [PMID: 34732868 DOI: 10.1038/s41586-021-03991-5] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Accepted: 09/01/2021] [Indexed: 11/09/2022]
Abstract
Baleen whales influence their ecosystems through immense prey consumption and nutrient recycling1-3. It is difficult to accurately gauge the magnitude of their current or historic ecosystem role without measuring feeding rates and prey consumed. To date, prey consumption of the largest species has been estimated using metabolic models3-9 based on extrapolations that lack empirical validation. Here, we used tags deployed on seven baleen whale (Mysticeti) species (n = 321 tag deployments) in conjunction with acoustic measurements of prey density to calculate prey consumption at daily to annual scales from the Atlantic, Pacific, and Southern Oceans. Our results suggest that previous studies3-9 have underestimated baleen whale prey consumption by threefold or more in some ecosystems. In the Southern Ocean alone, we calculate that pre-whaling populations of mysticetes annually consumed 430 million tonnes of Antarctic krill (Euphausia superba), twice the current estimated total biomass of E. superba10, and more than twice the global catch of marine fisheries today11. Larger whale populations may have supported higher productivity in large marine regions through enhanced nutrient recycling: our findings suggest mysticetes recycled 1.2 × 104 tonnes iron yr-1 in the Southern Ocean before whaling compared to 1.2 × 103 tonnes iron yr-1 recycled by whales today. The recovery of baleen whales and their nutrient recycling services2,3,7 could augment productivity and restore ecosystem function lost during 20th century whaling12,13.
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Affiliation(s)
- Matthew S Savoca
- Hopkins Marine Station, Stanford University, Pacific Grove, CA, USA.
| | - Max F Czapanskiy
- Hopkins Marine Station, Stanford University, Pacific Grove, CA, USA
| | | | - William T Gough
- Hopkins Marine Station, Stanford University, Pacific Grove, CA, USA
| | - James A Fahlbusch
- Hopkins Marine Station, Stanford University, Pacific Grove, CA, USA.,Cascadia Research Collective, Olympia, WA, USA
| | - K C Bierlich
- Duke University Marine Laboratory, Duke University, Beaufort, NC, USA.,Marine Mammal Institute, Hatfield Marine Science Center, Oregon State University, Newport, OR, USA
| | - Paolo S Segre
- Hopkins Marine Station, Stanford University, Pacific Grove, CA, USA
| | - Jacopo Di Clemente
- Department of Biology, University of Copenhagen, Copenhagen, Denmark.,Department of Biology, University of Southern Denmark, Odense, Denmark.,Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - Gwenith S Penry
- Institute for Coastal and Marine Research, Nelson Mandela University, Port Elizabeth, South Africa
| | - David N Wiley
- Stellwagen Bank National Marine Sanctuary, NOAA National Ocean Service, Scituate, MA, USA
| | | | - Douglas P Nowacek
- Duke University Marine Laboratory, Duke University, Beaufort, NC, USA
| | - David W Johnston
- Duke University Marine Laboratory, Duke University, Beaufort, NC, USA
| | - Nicholas D Pyenson
- Department of Paleobiology, National Museum of Natural History, Washington, DC, USA.,Department of Paleontology and Geology, Burke Museum of Natural History and Culture, Seattle, WA, USA
| | - Ari S Friedlaender
- Long Marine Laboratory, University of California, Santa Cruz, Santa Cruz, CA, USA
| | - Elliott L Hazen
- Hopkins Marine Station, Stanford University, Pacific Grove, CA, USA.,Long Marine Laboratory, University of California, Santa Cruz, Santa Cruz, CA, USA.,Environmental Research Division, NOAA Southwest Fisheries Science Center, Monterey, CA, USA
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23
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Complementary use of stable isotopes and fatty acids for quantitative diet estimation of sympatric predators, the Antarctic pack-ice seals. Oecologia 2021; 197:729-742. [PMID: 34626270 PMCID: PMC8585811 DOI: 10.1007/s00442-021-05045-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Accepted: 09/20/2021] [Indexed: 11/18/2022]
Abstract
The quantitative use of stable isotopes (SIs) for trophic studies has seen a rapid growth whereas fatty acid (FA) studies remain mostly qualitative. We apply the Bayesian tool MixSIAR to both SI and FA data to estimate the diet of three sympatric predators: the crabeater (Lobodon carcinophaga), Weddell (Leptonychotes weddellii) and leopard seal (Hydrurga leptonyx). We used SI data of their vibrissae and FA data of their outer blubber to produce comparable diet estimates for the same individuals. Both SI and FA models predicted the same main diet components, although the predicted proportions differed. For the crabeater seal, both methods identified krill, Euphausia superba, as the main, and almost exclusive, food item, although the FA model estimated a slightly lower proportion, potentially due to the low lipid content of krill compared to the fish species used in the model. For the Weddell seal the FA model identified the fish Pleuragramma antarcticum as the most important prey, whereas the SI model was not able to distinguish among prey species, identifying a ‘fish-squid’ group as the main diet component. For the leopard seal, both models identified krill as the main contributor; however, the predicted proportions for the secondary sources differed. Although vibrissae and outer blubber may not represent the same timeframe, the use of MixSIAR with FA data provides diet estimates comparable to those obtained with SI data, thus, both approaches were complimentary. The use of both biotracers offers a feasible option to study diets of wild animals in a quantitative manner.
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24
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Chenoweth EM, Boswell KM, Friedlaender AS, McPhee MV, Burrows JA, Heintz RA, Straley JM. Confronting assumptions about prey selection by lunge‐feeding whales using a process‐based model. Funct Ecol 2021. [DOI: 10.1111/1365-2435.13852] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ellen M. Chenoweth
- University of Alaska Fairbanks Fairbanks AK USA
- University of Alaska Southeast Sitka AK USA
| | | | - Ari S. Friedlaender
- University of California Santa Cruz Santa Cruz CA USA
- Oregon State University Newport OR USA
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25
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Modeling changes in baleen whale seasonal abundance, timing of migration, and environmental variables to explain the sudden rise in entanglements in California. PLoS One 2021; 16:e0248557. [PMID: 33857163 PMCID: PMC8049321 DOI: 10.1371/journal.pone.0248557] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 03/01/2021] [Indexed: 11/19/2022] Open
Abstract
We document changes in the number of sightings and timing of humpback (Megaptera novaeangliae), blue (Balaenoptera musculus), and gray (Eschrichtius robustus) whale migratory phases in the vicinity of the Farallon Islands, California. We hypothesized that changes in the timing of migration off central California were driven by local oceanography, regional upwelling, and basin-scale climate conditions. Using 24 years of daily whale counts collected from Southeast Farallon Island, we developed negative binomial regression models to evaluate trends in local whale sightings over time. We then used linear models to assess trends in the timing of migration, and to identify potential environmental drivers. These drivers included local, regional and basin-scale patterns; the latter included the El Niño Southern Oscillation, the Pacific Decadal Oscillation, and the North Pacific Gyre Oscillation, which influence, wind-driven upwelling, and overall productivity in the California Current System. We then created a forecast model to predict the timing of migration. Humpback whale sightings significantly increased over the study period, but blue and gray whale counts did not, though there was variability across the time series. Date of breeding migration (departure) for all species showed little to no change, whereas date of migration towards feeding areas (arrival) occurred earlier for humpback and blue whales. Timing was significantly influenced by a mix of local oceanography, regional, and basin-scale climate variables. Earlier arrival time without concomitant earlier departure time results in longer periods when blue and humpback whales are at risk of entanglement in the Gulf of the Farallones. We maintain that these changes have increased whale exposure to pot and trap fishery gear off the central California coast during the spring, elevating the risk of entanglements. Humpback entanglement rates were significantly associated with increased counts and early arrival in central California. Actions to decrease the temporal overlap between whales and pot/trap fishing gear, particularly when whales arrive earlier in warm water years, would likely decrease the risk of entanglements.
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26
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Abrahms B, Aikens EO, Armstrong JB, Deacy WW, Kauffman MJ, Merkle JA. Emerging Perspectives on Resource Tracking and Animal Movement Ecology. Trends Ecol Evol 2021; 36:308-320. [DOI: 10.1016/j.tree.2020.10.018] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 10/14/2020] [Accepted: 10/23/2020] [Indexed: 12/26/2022]
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27
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Mansouri F, Winfield ZC, Crain DD, Morris B, Charapata P, Sabin R, Potter CW, Hering AS, Fulton J, Trumble SJ, Usenko S. Evidence of multi-decadal behavior and ecosystem-level changes revealed by reconstructed lifetime stable isotope profiles of baleen whale earplugs. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 757:143985. [PMID: 33321341 DOI: 10.1016/j.scitotenv.2020.143985] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 11/11/2020] [Accepted: 11/14/2020] [Indexed: 06/12/2023]
Abstract
Biological time series datasets provide an unparalleled opportunity to investigate regional and global changes in the marine environment. Baleen whales are long-lived sentinel species and an integral part of the marine ecosystem. Increasing anthropogenic terrestrial and marine activities alter ocean systems, and such alterations could change foraging and feeding behavior of baleen whales. In this study, we analyzed δ13C and δ15N of baleen whale earplugs from three different species (N = 6 earplugs, n = 337 laminae) to reconstruct the first continuous stable isotope profiles with a six-month resolution. Results of our study provide an unprecedented opportunity to assess behavioral as well as ecological changes. Abrupt shifts and temporal variability observed in δ13C and δ15N profiles could be indicative of behavior change such as shift in foraging location and/or trophic level in response to natural or anthropogenic disturbances. Additionally, five out of six individuals demonstrated long-term declining trends in δ13C profiles, which could suggest influence of emission of depleted 13CO2 from fossil fuel combustion referred to as the Suess effect. After adjusting the δ13C values of earplugs for the estimated Suess effect and re-evaluating δ13C profiles, significant decline in δ13C values as well as different rate of depletion suggest contribution of other sources that could impact δ13C values at the base of the food web.
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Affiliation(s)
- Farzaneh Mansouri
- Department of Environmental Science, Baylor University, Waco, TX 76706, USA
| | - Zach C Winfield
- Department of Chemistry and Biochemistry, Baylor University, Waco, TX 76706, USA
| | | | - Brooke Morris
- Department of Biology, Baylor University, Waco, TX 76706, USA
| | | | - Richard Sabin
- Division of Vertebrates, Department of Life Sciences, Natural History Museum, London SW7 5BD, UK
| | - Charles W Potter
- Department of Vertebrate Zoology, Smithsonian Institution National Museum of Natural History, Washington, DC 20013, USA
| | - Amanda S Hering
- Department of Statistical Science, Baylor University, Waco, TX 76706, USA
| | - James Fulton
- Department of Geoscience, Baylor University, Waco, TX 76706, USA
| | | | - Sascha Usenko
- Department of Environmental Science, Baylor University, Waco, TX 76706, USA; Department of Chemistry and Biochemistry, Baylor University, Waco, TX 76706, USA; Department of Biology, Baylor University, Waco, TX 76706, USA.
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28
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Busquets-Vass G, Newsome SD, Pardo MA, Calambokidis J, Aguíñiga-García S, Páez-Rosas D, Gómez-Gutiérrez J, Enríquez-Paredes LM, Gendron D. Isotope-based inferences of the seasonal foraging and migratory strategies of blue whales in the eastern Pacific Ocean. MARINE ENVIRONMENTAL RESEARCH 2021; 163:105201. [PMID: 33162117 DOI: 10.1016/j.marenvres.2020.105201] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 10/15/2020] [Accepted: 10/24/2020] [Indexed: 06/11/2023]
Abstract
Migratory marine megafauna generally move vast distances between productive foraging grounds and environmentally stable breeding grounds, but characterizing how they use these habitats to maintain homeostasis and reproduce is difficult. We used isotope analysis of blue whale skin strata (n = 621) and potential prey (n = 300) to examine their migratory and foraging strategies in the eastern Pacific Ocean. Our results suggest that most whales in the northeast Pacific use a mixed income and capital breeding strategy, and use the California Current Ecosystem as their primary summer-fall foraging ground. A subset of individuals exhibited migratory plasticity and spend most of the year in the Gulf of California or Costa Rica Dome, two regions believed to be their primary winter-spring breeding grounds. Isotope data also revealed that whales in the southern Eastern Tropical Pacific generally do not forage in the northeast Pacific, which suggests a north-south population structure with a boundary near the equator.
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Affiliation(s)
- Geraldine Busquets-Vass
- Centro de Investigación Científica y Educación Superior de Ensenada, Unidad La Paz, Laboratorio de Macroecología Marina, Baja California Sur, Mexico; University of New Mexico, Biology Department, Albuquerque, NM, USA
| | - Seth D Newsome
- University of New Mexico, Biology Department, Albuquerque, NM, USA
| | - Mario A Pardo
- Consejo Nacional de Ciencia y Tecnología - Centro de Investigación Científica y Educación Superior de Ensenada, Unidad La Paz, Laboratorio de Macroecología Marina, Baja California Sur, Mexico
| | | | - Sergio Aguíñiga-García
- Instituto Politécnico Nacional, Centro Interdisciplinario de Ciencias Marinas, La Paz, Baja California Sur, Mexico
| | - Diego Páez-Rosas
- Universidad San Francisco de Quito, Galapagos Science Center, Av. Alsacio Northía, Isla San Cristóbal, Galápagos, Ecuador; Dirección del Parque Nacional Galápagos, Unidad Técnica Operativa San Cristóbal, Av. Perimetral, Isla San Cristóbal, Galápagos, Ecuador
| | - Jaime Gómez-Gutiérrez
- Instituto Politécnico Nacional, Centro Interdisciplinario de Ciencias Marinas, La Paz, Baja California Sur, Mexico
| | - Luis M Enríquez-Paredes
- Facultad de Ciencias Marinas, Universidad Autónoma de Baja California, Baja California, Mexico
| | - Diane Gendron
- Instituto Politécnico Nacional, Centro Interdisciplinario de Ciencias Marinas, La Paz, Baja California Sur, Mexico.
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29
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Kershaw JL, Ramp CA, Sears R, Plourde S, Brosset P, Miller PJO, Hall AJ. Declining reproductive success in the Gulf of St. Lawrence's humpback whales (Megaptera novaeangliae) reflects ecosystem shifts on their feeding grounds. GLOBAL CHANGE BIOLOGY 2020; 27:1027-1041. [PMID: 33368899 DOI: 10.1111/gcb.15466] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 11/17/2020] [Accepted: 11/17/2020] [Indexed: 06/12/2023]
Abstract
Climate change has resulted in physical and biological changes in the world's oceans. How the effects of these changes are buffered by top predator populations, and therefore how much plasticity lies at the highest trophic levels, are largely unknown. Here endocrine profiling, longitudinal observations of known individuals over 15 years between 2004 and 2018, and environmental data are combined to examine how the reproductive success of a top marine predator is being affected by ecosystem change. The Gulf of St. Lawrence, Canada, is a major summer feeding ground for humpback whales (Megaptera novaeangliae) in the North Atlantic. Blubber biopsy samples (n = 185) of female humpback whales were used to investigate variation in pregnancy rates through the quantification of progesterone. Annual pregnancy rates showed considerable variability, with no overall change detected over the study. However, a total of 457 photo-identified adult female sightings records with/without calves were collated, and showed that annual calving rates declined significantly. The probability of observing cow-calf pairs was related to favourable environmental conditions in the previous year; measured by herring spawning stock biomass, Calanus spp. abundance, overall copepod abundance and phytoplankton bloom magnitude. Approximately 39% of identified pregnancies were unsuccessful over the 15 years, and the average annual pregnancy rate was higher than the average annual calving rate at ~37% and ~23% respectively. Together, these data suggest that the declines in reproductive success could be, at least in part, the result of females being unable to accumulate the energy reserves necessary to maintain pregnancy and/or meet the energetic demands of lactation in years of poorer prey availability rather than solely an inability to become pregnant. The decline in calving rates over a period of major environmental variability may suggest that this population has limited resilience to such ecosystem change.
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Affiliation(s)
- Joanna L Kershaw
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews, UK
- Mingan Island Cetacean Study, Saint Lambert, QC, Canada
| | - Christian A Ramp
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews, UK
- Mingan Island Cetacean Study, Saint Lambert, QC, Canada
| | - Richard Sears
- Mingan Island Cetacean Study, Saint Lambert, QC, Canada
| | - Stéphane Plourde
- Department of Fisheries and Oceans Canada, Maurice Lamontagne Institute, Mont-Joli, QC, Canada
| | - Pablo Brosset
- Department of Fisheries and Oceans Canada, Maurice Lamontagne Institute, Mont-Joli, QC, Canada
- Laboratoire de Biologie Halieutique, Ifremer, Plouzané, France
- Laboratoire des Sciences de l'Environnement Marin - IUEM, Université de Brest - UMR 6539 CNRS/UBO/IRD/Ifremer, Plouzané, France
| | - Patrick J O Miller
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews, UK
| | - Ailsa J Hall
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews, UK
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30
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van den Berg GL, Vermeulen E, Valenzuela LO, Bérubé M, Ganswindt A, Gröcke DR, Hall G, Hulva P, Neveceralova P, Palsbøll PJ, Carroll EL. Decadal shift in foraging strategy of a migratory southern ocean predator. GLOBAL CHANGE BIOLOGY 2020; 27:1052-1067. [PMID: 33319502 DOI: 10.1111/gcb.15465] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 11/17/2020] [Accepted: 11/18/2020] [Indexed: 06/12/2023]
Abstract
Rapid anthropogenic environmental change is expected to impact a host of ecological parameters in Southern Ocean ecosystems. Of critical concern are the consequences of these changes on the range of species that show fidelity to migratory destinations, as philopatry is hypothesized to help or hinder adaptation to climate change depending on the circumstances. Many baleen whales show philopatry to feeding grounds and are also capital breeders that meet migratory and reproductive costs through seasonal energy intake. Southern right whales (Eubalaena australis, SRWs) are capital breeders that have a strong relationship between reproductive output and foraging success. The population dynamics of South Africa's population of SRWs are characterized by two distinct periods: the 1990s, a period of high calving rates; and the late 2010s, a period associated with lowered calving rates. Here we use analyses of stable carbon (δ13 C) and nitrogen (δ15 N) isotope values from SRW biopsy samples (n = 122) collected during these two distinct periods to investigate foraging ecology of the South African population of SRWs over a time period coincident with the demographic shift. We show that South African SRWs underwent a dramatic northward shift, and diversification, in foraging strategy from 1990s to 2010s. Bayesian mixing model results suggest that during the 1990s, South African SRWs foraged on prey isotopically similar to South Georgia/Islas Georgias del Sur krill. In contrast, in the 2010s, South African SRWs foraged on prey isotopically consistent with the waters of the Subtropical Convergence, Polar Front and Marion Island. We hypothesize that this shift represents a response to changes in preferred habitat or prey, for example, the decrease in abundance and southward range contraction of Antarctic krill. By linking reproductive decline to changing foraging strategies for the first time in SRWs, we show that altering foraging strategies may not be sufficient to adapt to a changing ocean.
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Affiliation(s)
- Gideon L van den Berg
- Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, Pretoria, South Africa
| | - Els Vermeulen
- Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, Pretoria, South Africa
| | - Luciano O Valenzuela
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Laboratorio de Ecología Evolutiva Humana (LEEH, Facultad de Ciencias Sociales, Unidad de Enseñanza Universitaria Quequén, UNCPBA, Buenos Aires, Argentina
- School of Biological Sciences, University of Utah, Salt Lake City, UT, USA
- Instituto de Conservación de Ballenas, Buenos Aires, Argentina
| | - Martine Bérubé
- Marine Evolution and Conservation Group, Groningen Institute of Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
- Centre for Coastal Studies, Provincetown, MA, USA
| | - Andre Ganswindt
- Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, Pretoria, South Africa
| | - Darren R Gröcke
- Stable Isotope Biogeochemistry Laboratory (SIBL), Department of Earth Sciences, Durham University, Durham, UK
| | - Grant Hall
- Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, Pretoria, South Africa
| | - Pavel Hulva
- Department of Zoology, Faculty of Science, Charles University, Prague, Czech Republic
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Ostrava, Czech Republic
| | - Petra Neveceralova
- Department of Zoology, Faculty of Science, Charles University, Prague, Czech Republic
- Ivanhoe Sea Safaris, Gansbaai, South Africa
- Dyer Island Conservation Trust, Great White House, Kleinbaai, South Africa
| | - Per J Palsbøll
- Marine Evolution and Conservation Group, Groningen Institute of Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
- Centre for Coastal Studies, Provincetown, MA, USA
| | - Emma L Carroll
- School of Biological Sciences, University of Auckland, Auckland, New Zealand
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31
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Interannual variability in the lipid and fatty acid profiles of east Australia-migrating humpback whales (Megaptera novaeangliae) across a 10-year timeline. Sci Rep 2020; 10:18274. [PMID: 33106590 PMCID: PMC7589506 DOI: 10.1038/s41598-020-75370-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Accepted: 10/12/2020] [Indexed: 02/02/2023] Open
Abstract
Southern hemisphere humpback whales are classified as high-fidelity Antarctic krill consumers and as such are vulnerable to variability and long-term changes in krill biomass. Evidence of heterogeneous feeding patterns of east coast of Australia migrating humpback whales has been observed, warranting a comprehensive assessment of interannual variability in their diet. We examined the lipid and fatty acid profiles of individuals of the east coast of Australia migrating stock sampled between 2008 and 2018. The use of live-sampled blubber biopsies showed that fatty acid profiles varied significantly among all years. The two trophic indicator fatty acids for Antarctic krill, 20:5ω3 and 22:6ω3 remained largely unchanged across the 10-year period, suggesting that Antarctic krill is the principal prey item. A distance-based linear model showed that 33% of the total variation in fatty acid profiles was explained by environmental variables and climate indices. Most of the variation was explained by the Southern Annular Mode (23.7%). The high degree of variability observed in this study was unexpected for a species that is thought to feed primarily on one prey item. We propose that the observed variability likely arises from changes in the diet of Antarctic krill rather than changes in the whale’s diet.
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Kahane-Rapport SR, Savoca MS, Cade DE, Segre PS, Bierlich KC, Calambokidis J, Dale J, Fahlbusch JA, Friedlaender AS, Johnston DW, Werth AJ, Goldbogen JA. Lunge filter feeding biomechanics constrain rorqual foraging ecology across scale. J Exp Biol 2020; 223:jeb224196. [PMID: 32820028 DOI: 10.1242/jeb.224196] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 08/13/2020] [Indexed: 10/23/2022]
Abstract
Fundamental scaling relationships influence the physiology of vital rates, which in turn shape the ecology and evolution of organisms. For diving mammals, benefits conferred by large body size include reduced transport costs and enhanced breath-holding capacity, thereby increasing overall foraging efficiency. Rorqual whales feed by engulfing a large mass of prey-laden water at high speed and filtering it through baleen plates. However, as engulfment capacity increases with body length (engulfment volume∝body length3.57), the surface area of the baleen filter does not increase proportionally (baleen area∝body length1.82), and thus the filtration time of larger rorquals predictably increases as the baleen surface area must filter a disproportionally large amount of water. We predicted that filtration time should scale with body length to the power of 1.75 (filter time∝body length1.75). We tested this hypothesis on four rorqual species using multi-sensor tags with corresponding unoccupied aircraft systems-based body length estimates. We found that filter time scales with body length to the power of 1.79 (95% CI: 1.61-1.97). This result highlights a scale-dependent trade-off between engulfment capacity and baleen area that creates a biomechanical constraint to foraging through increased filtration time. Consequently, larger whales must target high-density prey patches commensurate to the gulp size to meet their increased energetic demands. If these optimal patches are absent, larger rorquals may experience reduced foraging efficiency compared with smaller whales if they do not match their engulfment capacity to the size of targeted prey aggregations.
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Affiliation(s)
- S R Kahane-Rapport
- Department of Biology, Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA
| | - M S Savoca
- Department of Biology, Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA
| | - D E Cade
- Department of Biology, Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA
- Institute of Marine Sciences, University of California, Santa Cruz, Santa Cruz, CA, USA
| | - P S Segre
- Department of Biology, Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA
| | - K C Bierlich
- Nicholas School of the Environment, Duke University Marine Laboratory, Beaufort, NC 27710, USA
| | - J Calambokidis
- Cascadia Research Collective, 218 W. 4th Ave., Olympia, WA 98501, USA
| | - J Dale
- Nicholas School of the Environment, Duke University Marine Laboratory, Beaufort, NC 27710, USA
| | - J A Fahlbusch
- Department of Biology, Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA
| | - A S Friedlaender
- Institute of Marine Sciences, University of California, Santa Cruz, Santa Cruz, CA, USA
| | - D W Johnston
- Nicholas School of the Environment, Duke University Marine Laboratory, Beaufort, NC 27710, USA
| | - A J Werth
- Department of Biology, Hampden-Sydney College, Hampden-Sydney, VA 23943, USA
| | - J A Goldbogen
- Department of Biology, Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA
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Davis GE, Baumgartner MF, Corkeron PJ, Bell J, Berchok C, Bonnell JM, Bort Thornton J, Brault S, Buchanan GA, Cholewiak DM, Clark CW, Delarue J, Hatch LT, Klinck H, Kraus SD, Martin B, Mellinger DK, Moors‐Murphy H, Nieukirk S, Nowacek DP, Parks SE, Parry D, Pegg N, Read AJ, Rice AN, Risch D, Scott A, Soldevilla MS, Stafford KM, Stanistreet JE, Summers E, Todd S, Van Parijs SM. Exploring movement patterns and changing distributions of baleen whales in the western North Atlantic using a decade of passive acoustic data. GLOBAL CHANGE BIOLOGY 2020; 26:4812-4840. [PMID: 32450009 PMCID: PMC7496396 DOI: 10.1111/gcb.15191] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 04/13/2020] [Indexed: 05/13/2023]
Abstract
Six baleen whale species are found in the temperate western North Atlantic Ocean, with limited information existing on the distribution and movement patterns for most. There is mounting evidence of distributional shifts in many species, including marine mammals, likely because of climate-driven changes in ocean temperature and circulation. Previous acoustic studies examined the occurrence of minke (Balaenoptera acutorostrata) and North Atlantic right whales (NARW; Eubalaena glacialis). This study assesses the acoustic presence of humpback (Megaptera novaeangliae), sei (B. borealis), fin (B. physalus), and blue whales (B. musculus) over a decade, based on daily detections of their vocalizations. Data collected from 2004 to 2014 on 281 bottom-mounted recorders, totaling 35,033 days, were processed using automated detection software and screened for each species' presence. A published study on NARW acoustics revealed significant changes in occurrence patterns between the periods of 2004-2010 and 2011-2014; therefore, these same time periods were examined here. All four species were present from the Southeast United States to Greenland; humpback whales were also present in the Caribbean. All species occurred throughout all regions in the winter, suggesting that baleen whales are widely distributed during these months. Each of the species showed significant changes in acoustic occurrence after 2010. Similar to NARWs, sei whales had higher acoustic occurrence in mid-Atlantic regions after 2010. Fin, blue, and sei whales were more frequently detected in the northern latitudes of the study area after 2010. Despite this general northward shift, all four species were detected less on the Scotian Shelf area after 2010, matching documented shifts in prey availability in this region. A decade of acoustic observations have shown important distributional changes over the range of baleen whales, mirroring known climatic shifts and identifying new habitats that will require further protection from anthropogenic threats like fixed fishing gear, shipping, and noise pollution.
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Affiliation(s)
- Genevieve E. Davis
- NOAA Northeast Fisheries Science CenterWoods HoleMAUSA
- University of Massachusetts BostonBostonMAUSA
| | | | | | - Joel Bell
- Naval Facilities Engineering Command AtlanticNorfolkVAUSA
| | | | - Julianne M. Bonnell
- Integrated Statistics, Under contract to the NOAA Northeast Fisheries Science CenterWoods HoleMAUSA
| | | | | | | | | | - Christopher W. Clark
- Center for Conservation BioacousticsCornell Lab of OrnithologyCornell UniversityIthacaNYUSA
| | | | - Leila T. Hatch
- NOAA Stellwagen Bank National Marine SanctuaryScituateMAUSA
| | - Holger Klinck
- Center for Conservation BioacousticsCornell Lab of OrnithologyCornell UniversityIthacaNYUSA
| | - Scott D. Kraus
- Anderson Cabot Center for Ocean LifeNew England AquariumBostonMAUSA
| | | | - David K. Mellinger
- Oregon State University and NOAA Pacific Marine Environmental LaboratoryNewportORUSA
| | - Hilary Moors‐Murphy
- Fisheries and Oceans CanadaBedford Institute of OceanographyDartmouthNSCanada
| | - Sharon Nieukirk
- Oregon State University and NOAA Pacific Marine Environmental LaboratoryNewportORUSA
| | - Douglas P. Nowacek
- Nicholas School of the EnvironmentDuke University Marine LaboratoryBeaufortNCUSA
- Pratt School of EngineeringDuke UniversityDurhamNCUSA
| | | | - Dawn Parry
- Center for Conservation BioacousticsCornell Lab of OrnithologyCornell UniversityIthacaNYUSA
| | - Nicole Pegg
- Integrated Statistics, Under contract to the NOAA Northeast Fisheries Science CenterWoods HoleMAUSA
| | - Andrew J. Read
- Nicholas School of the EnvironmentDuke University Marine LaboratoryBeaufortNCUSA
| | - Aaron N. Rice
- Center for Conservation BioacousticsCornell Lab of OrnithologyCornell UniversityIthacaNYUSA
| | - Denise Risch
- The Scottish Association for Marine Science (SAMS)ObanUK
| | - Alyssa Scott
- Integrated Statistics, Under contract to the NOAA Northeast Fisheries Science CenterWoods HoleMAUSA
| | | | | | - Joy E. Stanistreet
- Fisheries and Oceans CanadaBedford Institute of OceanographyDartmouthNSCanada
| | - Erin Summers
- Maine Department of Marine ResourcesWest Boothbay HarborMEUSA
| | - Sean Todd
- Allied WhaleCollege of the AtlanticBar HarborMEUSA
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Fiechter J, Santora JA, Chavez F, Northcott D, Messié M. Krill Hotspot Formation and Phenology in the California Current Ecosystem. GEOPHYSICAL RESEARCH LETTERS 2020; 47:e2020GL088039. [PMID: 32728303 PMCID: PMC7380319 DOI: 10.1029/2020gl088039] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Revised: 05/28/2020] [Accepted: 06/04/2020] [Indexed: 06/11/2023]
Abstract
In the California Current Ecosystem, krill represent a key link between primary production and higher trophic level species owing to their central position in the food web and tendency to form dense aggregations. However, the strongly advective circulation associated with coastal upwelling may decouple the timing, occurrence, and persistence of krill hotspots from phytoplankton biomass and nutrient sources. Results from a coupled physical-biological model provide insights into fundamental mechanisms controlling the phenology of krill hotspots in the California Current Ecosystem, and their sensitivity to alongshore changes in coastal upwelling intensity. The simulation indicates that dynamics controlling krill hotspot formation, intensity, and persistence on seasonal and interannual timescales are strongly heterogeneous and related to alongshore variations in upwelling-favorable winds, primary production, and ocean currents. Furthermore, regions promoting persistent krill hotspot formation coincide with increased observed abundance of top predators, indicating that the model resolves important ecosystem complexity and function.
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Affiliation(s)
- Jerome Fiechter
- Ocean Sciences DepartmentUniversity of CaliforniaSanta CruzCAUSA
| | - Jarrod A. Santora
- Fisheries Ecology Division, Southwest Fisheries Science Center, National Marine Fisheries ServiceNational Oceanic and Atmospheric AdministrationSanta CruzCAUSA
- Department of Applied MathematicsUniversity of CaliforniaSanta CruzCAUSA
| | | | - Devon Northcott
- Monterey Bay Aquarium Research InstituteMoss LandingCAUSA
- Now at Scripps Institution of OceanographyUniversity of California, San DiegoLa JollaCAUSA
| | - Monique Messié
- Monterey Bay Aquarium Research InstituteMoss LandingCAUSA
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Rockwood RC, Elliott ML, Saenz B, Nur N, Jahncke J. Modeling predator and prey hotspots: Management implications of baleen whale co-occurrence with krill in Central California. PLoS One 2020; 15:e0235603. [PMID: 32634142 PMCID: PMC7340285 DOI: 10.1371/journal.pone.0235603] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 06/19/2020] [Indexed: 11/19/2022] Open
Abstract
As global ocean-bound commerce increases, managing human activities has become important in reducing conflict with threatened wildlife. This study investigates environmental factors determining abundance and distribution of blue whales (Balaenoptera musculus), humpback whales (Megaptera novaeangliae) and their prey (Euphausia pacifica and Thysanoessa spinifera) in central California. We provide insights into environmental drivers of the ecology and distribution of these species, model whale distributions and determine coincident hotspots of whales and their prey that will help decrease human threats to whales and protect critical feeding habitat. We developed separate predictive models of whale abundances (using negative binomial regression on count data) and krill abundance (using a two-part hurdlemodel combining logistic and negative binomial regressions) over a 14 year period (2004-2017). Variables included in situ surface and midwater oceanographic measures (temperature, salinity, and fluorescence), basin-scale climate indices, and bathymetric- and distance-related data. Predictions were applied to 1 km2 cells spanning the study area for May, June, July, and September during each of the 14 years of surveys to identify persistent distribution patterns. Both whales and krill were found to consistently use the northeast region of Cordell Bank, the Farallon Escarpment, and the shelf-break waters. The main identified blue whale hotspots were also krill hotspots, while co-occurrence was more limited and varied seasonally for humpback whales and krill. These results are valuable in identifying patterns in important areas of ecological interaction to assist management of whales. Areas north of Cordell Bank are of particular management concern since they overlap with the end of the San Francisco Bay northern shipping lane. Our findings can help decrease threats to whales, particularly in important foraging areas, by supporting implementation of vessel management and informing potential conflicts with other human uses.
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Affiliation(s)
| | | | | | - Nadav Nur
- Point Blue Conservation Science, Petaluma, CA, United States of America
| | - Jaime Jahncke
- Point Blue Conservation Science, Petaluma, CA, United States of America
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36
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Habitat compression and ecosystem shifts as potential links between marine heatwave and record whale entanglements. Nat Commun 2020; 11:536. [PMID: 31988285 PMCID: PMC6985238 DOI: 10.1038/s41467-019-14215-w] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Accepted: 12/13/2019] [Indexed: 12/03/2022] Open
Abstract
Climate change and increased variability and intensity of climate events, in combination with recovering protected species populations and highly capitalized fisheries, are posing new challenges for fisheries management. We examine socio-ecological features of the unprecedented 2014–2016 northeast Pacific marine heatwave to understand the potential causes for record numbers of whale entanglements in the central California Current crab fishery. We observed habitat compression of coastal upwelling, changes in availability of forage species (krill and anchovy), and shoreward distribution shift of foraging whales. We propose that these ecosystem changes, combined with recovering whale populations, contributed to the exacerbation of entanglements throughout the marine heatwave. In 2016, domoic acid contamination prompted an unprecedented delay in the opening of California’s Dungeness crab fishery that inadvertently intensified the spatial overlap between whales and crab fishery gear. We present a retroactive assessment of entanglements to demonstrate that cooperation of fishers, resource managers, and scientists could mitigate future entanglement risk by developing climate-ready fisheries approaches, while supporting thriving fishing communities. Climate-driven extreme events may have strong local impacts on marine organisms and fisheries. Here the authors report increased whale entanglements in the northeast Pacific following a marine heatwave, and propose compression of coastal upwelling habitat as the potential driver.
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Cade DE, Carey N, Domenici P, Potvin J, Goldbogen JA. Predator-informed looming stimulus experiments reveal how large filter feeding whales capture highly maneuverable forage fish. Proc Natl Acad Sci U S A 2020; 117:472-478. [PMID: 31871184 PMCID: PMC6955359 DOI: 10.1073/pnas.1911099116] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The unique engulfment filtration strategy of microphagous rorqual whales has evolved relatively recently (<5 Ma) and exploits extreme predator/prey size ratios to overcome the maneuverability advantages of swarms of small prey, such as krill. Forage fish, in contrast, have been engaged in evolutionary arms races with their predators for more than 100 million years and have performance capabilities that suggest they should easily evade whale-sized predators, yet they are regularly hunted by some species of rorqual whales. To explore this phenomenon, we determined, in a laboratory setting, when individual anchovies initiated escape from virtually approaching whales, then used these results along with in situ humpback whale attack data to model how predator speed and engulfment timing affected capture rates. Anchovies were found to respond to approaching visual looming stimuli at expansion rates that give ample chance to escape from a sea lion-sized predator, but humpback whales could capture as much as 30-60% of a school at once because the increase in their apparent (visual) size does not cross their prey's response threshold until after rapid jaw expansion. Humpback whales are, thus, incentivized to delay engulfment until they are very close to a prey school, even if this results in higher hydrodynamic drag. This potential exaptation of a microphagous filter feeding strategy for fish foraging enables humpback whales to achieve 7× the energetic efficiency (per lunge) of krill foraging, allowing for flexible foraging strategies that may underlie their ecological success in fluctuating oceanic conditions.
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Affiliation(s)
- David E Cade
- Hopkins Marine Station, Department of Biology, Stanford University, Pacific Grove, CA 93950;
| | - Nicholas Carey
- Hopkins Marine Station, Department of Biology, Stanford University, Pacific Grove, CA 93950
| | - Paolo Domenici
- Istituto per lo studio degli impatti Antropici e Sostenibilità in ambiente marino, Consiglio Nazionale delle Ricerche, IAS-CNR, 09170, Torregrande, Oristano, Italy
| | - Jean Potvin
- Department of Physics, Saint Louis University, St. Louis, MO 63103
| | - Jeremy A Goldbogen
- Hopkins Marine Station, Department of Biology, Stanford University, Pacific Grove, CA 93950
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St. John Glew K, Wanless S, Harris MP, Daunt F, Erikstad KE, Strøm H, Speakman JR, Kürten B, Trueman CN. Sympatric Atlantic puffins and razorbills show contrasting responses to adverse marine conditions during winter foraging within the North Sea. MOVEMENT ECOLOGY 2019; 7:33. [PMID: 31695919 PMCID: PMC6824136 DOI: 10.1186/s40462-019-0174-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 09/20/2019] [Indexed: 06/10/2023]
Abstract
BACKGROUND Natural environments are dynamic systems with conditions varying across years. Higher trophic level consumers may respond to changes in the distribution and quality of available prey by moving to locate new resources or by switching diets. In order to persist, sympatric species with similar ecological niches may show contrasting foraging responses to changes in environmental conditions. However, in marine environments this assertion remains largely untested for highly mobile predators outside the breeding season because of the challenges of quantifying foraging location and trophic position under contrasting conditions. METHOD Differences in overwinter survival rates of two populations of North Sea seabirds (Atlantic puffins (Fratercula arctica) and razorbills (Alca torda)) indicated that environmental conditions differed between 2007/08 (low survival and thus poor conditions) and 2014/15 (higher survival, favourable conditions). We used a combination of bird-borne data loggers and stable isotope analyses to test 1) whether these sympatric species showed consistent responses with respect to foraging location and trophic position to these contrasting winter conditions during periods when body and cheek feathers were being grown (moult) and 2) whether any observed changes in moult locations and diet could be related to the abundance and distribution of potential prey species of differing energetic quality. RESULTS Puffins and razorbills showed divergent foraging responses to contrasting winter conditions. Puffins foraging in the North Sea used broadly similar foraging locations during moult in both winters. However, puffin diet significantly differed, with a lower average trophic position in the winter characterised by lower survival rates. By contrast, razorbills' trophic position increased in the poor survival winter and the population foraged in more distant southerly waters of the North Sea. CONCLUSIONS Populations of North Sea puffins and razorbills showed contrasting foraging responses when environmental conditions, as indicated by overwinter survival differed. Conservation of mobile predators, many of which are in sharp decline, may benefit from dynamic spatial based management approaches focusing on behavioural changes in response to changing environmental conditions, particularly during life history stages associated with increased mortality.
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Affiliation(s)
- Katie St. John Glew
- Ocean and Earth Science, University of Southampton, Waterfront Campus, Southampton, SO143ZH UK
| | - Sarah Wanless
- Centre for Ecology & Hydrology, Bush Estate, Penicuik, EH26 0QB UK
| | | | - Francis Daunt
- Centre for Ecology & Hydrology, Bush Estate, Penicuik, EH26 0QB UK
| | - Kjell Einar Erikstad
- Norwegian Institute for Nature Research, Fram Centre, N-9296 Tromsø, Norway
- Norwegian University of Science &Technology (NTNU), Centre for Biodiversity Dynamics, Department of Biology, N-7491 Trondheim, Norway
| | - Hallvard Strøm
- Norwegian Polar Institute, Fram Centre, Postbox 6606, Langnes, NO-9296 Tromsø, Norway
| | - John R. Speakman
- Institute of Genetics and developmental Biology, Chinese Academy of Sciences, Beijing, China
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, Scotland, UK
| | - Benjamin Kürten
- School of Natural and Environmental Sciences, University of Newcastle, Newcastle-upon-Tyne, NE1 7RU UK
- Present address: King Abdullah University of Science and Technology (KAUST), Red Sea Research Center (RSRC), Biological and Environmental Sciences & Engineering Division (BESE), Thuwal, 23955-6900 Saudi Arabia
| | - Clive N. Trueman
- Ocean and Earth Science, University of Southampton, Waterfront Campus, Southampton, SO143ZH UK
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Kosma MM, Werth AJ, Szabo AR, Straley JM. Pectoral herding: an innovative tactic for humpback whale foraging. ROYAL SOCIETY OPEN SCIENCE 2019; 6:191104. [PMID: 31824717 PMCID: PMC6837203 DOI: 10.1098/rsos.191104] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/22/2019] [Accepted: 09/23/2019] [Indexed: 06/10/2023]
Abstract
Humpback whales (Megaptera novaeangliae) have exceptionally long pectorals (i.e. flippers) that aid in shallow water navigation, rapid acceleration and increased manoeuvrability. The use of pectorals to herd or manipulate prey has been hypothesized since the 1930s. We combined new technology and a unique viewing platform to document the additional use of pectorals to aggregate prey during foraging events. Here, we provide a description of 'pectoral herding' and explore the conditions that may promote this innovative foraging behaviour. Specifically, we analysed aerial videos and photographic sequences to assess the function of pectorals during feeding events near salmon hatchery release sites in Southeast Alaska (2016-2018). We observed the use of solo bubble-nets to initially corral prey, followed by calculated movements to establish a secondary boundary with the pectorals-further condensing prey and increasing foraging efficiency. We found three ways in which humpback whales use pectorals to herd prey: (i) create a physical barrier to prevent evasion, (ii) cause water motion to guide prey towards the mouth, and (iii) position the ventral side to reflect light and alter prey movement. Our findings suggest that behavioural plasticity may aid foraging in changing environments and shifts in prey availability. Further study would clarify if 'pectoral herding' is used as a principal foraging tool by the broader humpback whale population and the conditions that promote its use.
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Affiliation(s)
- Madison M. Kosma
- College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Juneau, AK 99801, USA
| | - Alexander J. Werth
- Department of Biology, Hampden-Sydney College, Hampden-Sydney, VA 23943, USA
| | | | - Janice M. Straley
- Department of Natural Sciences, University of Alaska Southeast, Sitka, AK 99835, USA
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Ryan JP, Cline DE, Joseph JE, Margolina T, Santora JA, Kudela RM, Chavez FP, Pennington JT, Wahl C, Michisaki R, Benoit-Bird K, Forney KA, Stimpert AK, DeVogelaere A, Black N, Fischer M. Humpback whale song occurrence reflects ecosystem variability in feeding and migratory habitat of the northeast Pacific. PLoS One 2019; 14:e0222456. [PMID: 31525231 PMCID: PMC6746543 DOI: 10.1371/journal.pone.0222456] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2019] [Accepted: 08/30/2019] [Indexed: 11/20/2022] Open
Abstract
This study examines the occurrence of humpback whale (Megaptera novaeangliae) song in the northeast Pacific from three years of continuous recordings off central California (36.713°N, 122.186°W). Song is prevalent in this feeding and migratory habitat, spanning nine months of the year (September-May), peaking in winter (November-January), and reaching a maximum of 86% temporal coverage (during November 2017). From the rise of song in fall through the end of peak occurrence in winter, song length increases significantly from month to month. The seasonal peak in song coincides with the seasonal trough in day length and sighting-based evidence of whales leaving Monterey Bay, consistent with seasonal migration. During the seasonal song peak, diel variation shows maximum occurrence at night (69% of the time), decreasing during dawn and dusk (52%), and further decreasing with increasing solar elevation during the day, reaching a minimum near solar noon (30%). Song occurrence increased 44% and 55% between successive years. Sighting data within the acoustic detection range of the hydrophone indicate that variation in local population density was an unlikely cause of this large interannual variation. Hydrographic data and modeling of acoustic transmission indicate that changes in neither habitat occupancy nor acoustic transmission were probable causes. Conversely, the positive interannual trend in song paralleled major ecosystem variations, including similarly large positive trends in wind-driven upwelling, primary productivity, and krill abundance. Further, the lowest song occurrence during the first year coincided with anomalously warm ocean temperatures and an extremely toxic harmful algal bloom that affected whales and other marine mammals in the region. These major ecosystem variations may have influenced the health and behavior of humpback whales during the study period.
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Affiliation(s)
- John P. Ryan
- Monterey Bay Aquarium Research Institute, Moss Landing, California, United States of America
| | - Danelle E. Cline
- Monterey Bay Aquarium Research Institute, Moss Landing, California, United States of America
| | - John E. Joseph
- Department of Oceanography, Naval Postgraduate School, Monterey, California, United States of America
| | - Tetyana Margolina
- Department of Oceanography, Naval Postgraduate School, Monterey, California, United States of America
| | - Jarrod A. Santora
- Department of Applied Mathematics, University of California Santa Cruz, Santa Cruz, California, United States of America
| | - Raphael M. Kudela
- Ocean Sciences Department, University of California Santa Cruz, Santa Cruz, California, United States of America
| | - Francisco P. Chavez
- Monterey Bay Aquarium Research Institute, Moss Landing, California, United States of America
| | - J. Timothy Pennington
- Monterey Bay Aquarium Research Institute, Moss Landing, California, United States of America
| | - Christopher Wahl
- Monterey Bay Aquarium Research Institute, Moss Landing, California, United States of America
| | - Reiko Michisaki
- Monterey Bay Aquarium Research Institute, Moss Landing, California, United States of America
| | - Kelly Benoit-Bird
- Monterey Bay Aquarium Research Institute, Moss Landing, California, United States of America
| | - Karin A. Forney
- Marine Mammal & Turtle Division, Southwest Fisheries Science Center, National Marine Fisheries Service, NOAA, Moss Landing, California, United States of America
- Moss Landing Marine Laboratories, San Jose State University, Moss Landing, California, United States of America
| | - Alison K. Stimpert
- Bioacoustics/Vertebrate Ecology, San Jose State University, Moss Landing Marine Laboratories, Moss Landing, California, United States of America
| | - Andrew DeVogelaere
- Monterey Bay National Marine Sanctuary, National Ocean Service, National Oceanic and Atmospheric Administration, Monterey, California, United States of America
| | - Nancy Black
- Monterey Bay Whale Watch, Monterey, California, United States of America
| | - Mark Fischer
- Aguasonic Acoustics, Santa Clara, California, United States of America
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Friedman WR, Martin BT, Wells BK, Warzybok P, Michel CJ, Danner EM, Lindley ST. Modeling composite effects of marine and freshwater processes on migratory species. Ecosphere 2019. [DOI: 10.1002/ecs2.2743] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Affiliation(s)
- Whitney R. Friedman
- Institute of Marine Sciences University of California 100 McAllister Way Santa Cruz California USA
- Fisheries Ecology Division Southwest Fisheries Science Center National Marine Fisheries Service National Oceanic Atmospheric Administration 110 McAllister Way Santa Cruz California USA
| | - Benjamin T. Martin
- Fisheries Ecology Division Southwest Fisheries Science Center National Marine Fisheries Service National Oceanic Atmospheric Administration 110 McAllister Way Santa Cruz California USA
| | - Brian K. Wells
- Fisheries Ecology Division Southwest Fisheries Science Center National Marine Fisheries Service National Oceanic Atmospheric Administration 110 McAllister Way Santa Cruz California USA
| | - Pete Warzybok
- Point Blue Conservation Science Petaluma California USA
| | - Cyril J. Michel
- Institute of Marine Sciences University of California 100 McAllister Way Santa Cruz California USA
- Fisheries Ecology Division Southwest Fisheries Science Center National Marine Fisheries Service National Oceanic Atmospheric Administration 110 McAllister Way Santa Cruz California USA
| | - Eric M. Danner
- Fisheries Ecology Division Southwest Fisheries Science Center National Marine Fisheries Service National Oceanic Atmospheric Administration 110 McAllister Way Santa Cruz California USA
| | - Steven T. Lindley
- Fisheries Ecology Division Southwest Fisheries Science Center National Marine Fisheries Service National Oceanic Atmospheric Administration 110 McAllister Way Santa Cruz California USA
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42
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Merkens KP, Simonis AE, Oleson EM. Geographic and temporal patterns in the acoustic detection of sperm whales Physeter macrocephalus in the central and western North Pacific Ocean. ENDANGER SPECIES RES 2019. [DOI: 10.3354/esr00960] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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43
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Cartwright R, Venema A, Hernandez V, Wyels C, Cesere J, Cesere D. Fluctuating reproductive rates in Hawaii's humpback whales, Megaptera novaeangliae, reflect recent climate anomalies in the North Pacific. ROYAL SOCIETY OPEN SCIENCE 2019; 6:181463. [PMID: 31032006 PMCID: PMC6458358 DOI: 10.1098/rsos.181463] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 02/20/2019] [Indexed: 06/01/2023]
Abstract
Alongside changing ocean temperatures and ocean chemistry, anthropogenic climate change is now impacting the fundamental processes that support marine systems. However, where natural climate aberrations mask or amplify the impacts of anthropogenic climate change, identifying key detrimental changes is challenging. In these situations, long-term, systematic field studies allow the consequences of anthropogenically driven climate change to be distinguished from the expected fluctuations in natural resources. In this study, we describe fluctuations in encounter rates for humpback whales, Megaptera novaeangliae, between 2008 and 2018. Encounter rates were assessed during transect surveys of the Au'Au Channel, Maui, Hawaii. Initially, rates increased, tracking projected growth rates for this population segment. Rates reached a peak in 2013, then declined through 2018. Specifically, between 2013 and 2018, mother-calf encounter rates dropped by 76.5%, suggesting a rapid reduction in the reproductive rate of the newly designated Hawaii Distinct Population Segment of humpback whales during this time. As this decline coincided with changes in the Pacific decadal oscillation, the development of the NE Pacific marine heat wave and the evolution of the 2016 El Niño, this may be another example of the impact of this potent trifecta of climatic events within the North Pacific.
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Affiliation(s)
- R. Cartwright
- The Keiki Kohola Project, Kihei, HI 96753, USA
- Department of Environmental Science and Resource Management, California State University Channel Islands, One University Drive, Camarillo, CA 93012, USA
| | - A. Venema
- The Keiki Kohola Project, Kihei, HI 96753, USA
| | | | - C. Wyels
- The Keiki Kohola Project, Kihei, HI 96753, USA
- Department of Mathematics, California State University Channel Islands, One University Drive, Camarillo, CA 93012, USA
| | - J. Cesere
- The Keiki Kohola Project, Kihei, HI 96753, USA
- Fine Art Photography, Paia, HI 96779, USA
| | - D. Cesere
- The Keiki Kohola Project, Kihei, HI 96753, USA
- Fine Art Photography, Paia, HI 96779, USA
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44
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Abstract
In terrestrial systems, the green wave hypothesis posits that migrating animals can enhance foraging opportunities by tracking phenological variation in high-quality forage across space (i.e., "resource waves"). To track resource waves, animals may rely on proximate cues and/or memory of long-term average phenologies. Although there is growing evidence of resource tracking in terrestrial migrants, such drivers remain unevaluated in migratory marine megafauna. Here we present a test of the green wave hypothesis in a marine system. We compare 10 years of blue whale movement data with the timing of the spring phytoplankton bloom resulting in increased prey availability in the California Current Ecosystem, allowing us to investigate resource tracking both contemporaneously (response to proximate cues) and based on climatological conditions (memory) during migrations. Blue whales closely tracked the long-term average phenology of the spring bloom, but did not track contemporaneous green-up. In addition, blue whale foraging locations were characterized by low long-term habitat variability and high long-term productivity compared with contemporaneous measurements. Results indicate that memory of long-term average conditions may have a previously underappreciated role in driving migratory movements of long-lived species in marine systems, and suggest that these animals may struggle to respond to rapid deviations from historical mean environmental conditions. Results further highlight that an ecological theory of migration is conserved across marine and terrestrial systems. Understanding the drivers of animal migration is critical for assessing how environmental changes will affect highly mobile fauna at a global scale.
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45
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Becker EA, Forney KA, Redfern JV, Barlow J, Jacox MG, Roberts JJ, Palacios DM. Predicting cetacean abundance and distribution in a changing climate. DIVERS DISTRIB 2018. [DOI: 10.1111/ddi.12867] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Affiliation(s)
- Elizabeth A. Becker
- Marine Mammal and Turtle Division, Southwest Fisheries Science Center, National Marine Fisheries Service National Oceanic and Atmospheric Administration La Jolla California
- ManTech International Corporation Solana Beach California
| | - Karin A. Forney
- Marine Mammal and Turtle Division, Southwest Fisheries Science Center, National Marine Fisheries Service National Oceanic and Atmospheric Administration Moss Landing California
- Moss Landing Marine Laboratories Moss Landing California
| | - Jessica V. Redfern
- Marine Mammal and Turtle Division, Southwest Fisheries Science Center, National Marine Fisheries Service National Oceanic and Atmospheric Administration La Jolla California
| | - Jay Barlow
- Marine Mammal and Turtle Division, Southwest Fisheries Science Center, National Marine Fisheries Service National Oceanic and Atmospheric Administration La Jolla California
| | - Michael G. Jacox
- Environmental Research Division Southwest Fisheries Science Center Monterey California
- Physical Sciences Division Earth System Research Laboratory Boulder Colorado
| | - Jason J. Roberts
- Marine Geospatial Ecology Laboratory, Nicholas School of the Environment Duke University Durham North Carolina
| | - Daniel M. Palacios
- Marine Mammal Institute and Department of Fisheries and Wildlife, Hatfield Marine Science Center Oregon State University Newport Oregon
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46
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Wild LA, Chenoweth EM, Mueter FJ, Straley JM. Evidence for dietary time series in layers of cetacean skin using stable carbon and nitrogen isotope ratios. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2018; 32:1425-1438. [PMID: 29777550 PMCID: PMC6097889 DOI: 10.1002/rcm.8168] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2018] [Revised: 05/05/2018] [Accepted: 05/06/2018] [Indexed: 05/22/2023]
Abstract
RATIONALE Stable isotope analysis integrates diet information over a time period specific to the type of tissue sampled. For metabolically active skin of free-ranging cetaceans, cells are generated at the basal layer of the skin and migrate outward until they eventually slough off, suggesting potential for a dietary time series. METHODS Skin samples from cetaceans were analyzed using continuous-flow elemental analyzer isotope ratio mass spectrometry. We used ANOVAs to compare the variability of δ13 C and δ15 N values within and among layers and columns ("cores") of the skin of a fin, humpback, and sperm whale. We then used mixed-effects models to analyze isotopic variability among layers of 28 sperm whale skin samples, over the course of a season and among years. RESULTS We found layer to be a significant predictor of δ13 C values in the sperm whale's skin, and δ15 N values in the humpback whale's skin. There was no evidence for significant differences in δ15 N or δ13 C values among cores for any species. Mixed-effects models selected layer and day of the year as significant predictors of δ13 C and δ15 N values in sperm whale skin across individuals sampled during the summer months in the Gulf of Alaska. CONCLUSIONS These results suggest that skin samples from cetaceans may be subsampled to reflect diet during a narrower time period; specifically different layers of skin may contain a dietary time series. This underscores the importance of selecting an appropriate portion of skin to analyze based on the species and objectives of the study.
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Affiliation(s)
- Lauren A. Wild
- University of Alaska Fairbanks, Juneau, AK 99801 USA
- Corresponding author;
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47
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Goldbogen JA, Madsen PT. The evolution of foraging capacity and gigantism in cetaceans. ACTA ACUST UNITED AC 2018; 221:221/11/jeb166033. [PMID: 29895582 DOI: 10.1242/jeb.166033] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The extant diversity and rich fossil record of cetaceans provides an extraordinary evolutionary context for investigating the relationship between form, function and ecology. The transition from terrestrial to marine ecosystems is associated with a complex suite of morphological and physiological adaptations that were required for a fully aquatic mammalian life history. Two specific functional innovations that characterize the two great clades of cetaceans, echolocation in toothed whales (Odontoceti) and filter feeding in baleen whales (Mysticeti), provide a powerful comparative framework for integrative studies. Both clades exhibit gigantism in multiple species, but we posit that large body size may have evolved for different reasons and in response to different ecosystem conditions. Although these foraging adaptations have been studied using a combination of experimental and tagging studies, the precise functional drivers and consequences of morphological change within and among these lineages remain less understood. Future studies that focus at the interface of physiology, ecology and paleontology will help elucidate how cetaceans became the largest predators in aquatic ecosystems worldwide.
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Affiliation(s)
- J A Goldbogen
- Department of Biology, Hopkins Marine Station, Stanford University, 120 Ocean View Boulevard, Pacific Grove, CA 93950, USA
| | - P T Madsen
- Zoophysiology, Department of Bioscience, Aarhus University, C.F. Møllers Allé 3, 8000 Aarhus C, Denmark.,Aarhus Institute of Advanced Studies, Høegh-Guldbergs Gade 6B, DK-8000 Aarhus C, Denmark
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48
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Pyenson ND, Vermeij GJ. The rise of ocean giants: maximum body size in Cenozoic marine mammals as an indicator for productivity in the Pacific and Atlantic Oceans. Biol Lett 2017; 12:rsbl.2016.0186. [PMID: 27381883 PMCID: PMC4971165 DOI: 10.1098/rsbl.2016.0186] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 06/13/2016] [Indexed: 11/12/2022] Open
Abstract
Large consumers have ecological influence disproportionate to their abundance, although this influence in food webs depends directly on productivity. Evolutionary patterns at geologic timescales inform expectations about the relationship between consumers and productivity, but it is very difficult to track productivity through time with direct, quantitative measures. Based on previous work that used the maximum body size of Cenozoic marine invertebrate assemblages as a proxy for benthic productivity, we investigated how the maximum body size of Cenozoic marine mammals, in two feeding guilds, evolved over comparable temporal and geographical scales. First, maximal size in marine herbivores remains mostly stable and occupied by two different groups (desmostylians and sirenians) over separate timeframes in the North Pacific Ocean, while sirenians exclusively dominated this ecological mode in the North Atlantic. Second, mysticete whales, which are the largest Cenozoic consumers in the filter-feeding guild, remained in the same size range until a Mio-Pliocene onset of cetacean gigantism. Both vertebrate guilds achieved very large size only recently, suggesting that different trophic mechanisms promoting gigantism in the oceans have operated in the Cenozoic than in previous eras.
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Affiliation(s)
- Nicholas D Pyenson
- Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, PO Box 37012, Washington, DC 20013-7013, USA Department of Paleontology, Burke Museum of Natural History and Culture, Seattle, WA 98195, USA
| | - Geerat J Vermeij
- Department of Earth and Planetary Sciences, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA
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49
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Abrahms B, Hazen EL, Bograd SJ, Brashares JS, Robinson PW, Scales KL, Crocker DE, Costa DP. Climate mediates the success of migration strategies in a marine predator. Ecol Lett 2017; 21:63-71. [PMID: 29096419 DOI: 10.1111/ele.12871] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Revised: 06/30/2017] [Accepted: 09/25/2017] [Indexed: 12/25/2022]
Abstract
Individual behavioural specialisation has far-reaching effects on fitness and population persistence. Theory predicts that unconditional site fidelity, that is fidelity to a site independent of past outcome, provides a fitness advantage in unpredictable environments. However, the benefits of alternative site fidelity strategies driving intraspecific variation remain poorly understood and have not been evaluated in different environmental contexts. We show that contrary to expectation, strong and weak site fidelity strategies in migratory northern elephant seals performed similarly over 10 years, but the success of each strategy varied interannually and was strongly mediated by climate conditions. Strong fidelity facilitated stable energetic rewards and low risk, while weak fidelity facilitated high rewards and high risk. Weak fidelity outperformed strong fidelity in anomalous climate conditions, suggesting that the evolutionary benefits of site fidelity may be upended by increasing environmental variability. We highlight how individual behavioural specialisation may modulate the adaptive capacity of species to climate change.
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Affiliation(s)
- Briana Abrahms
- NOAA Southwest Fisheries Science Center, Environmental Research Division, 99 Pacific St. #255A, Monterey, CA, 93940, USA.,Department of Ecology and Evolutionary Biology, University of California Santa Cruz, 115 McAllister Way, Santa Cruz, CA, 95060, USA
| | - Elliott L Hazen
- NOAA Southwest Fisheries Science Center, Environmental Research Division, 99 Pacific St. #255A, Monterey, CA, 93940, USA.,Department of Ecology and Evolutionary Biology, University of California Santa Cruz, 115 McAllister Way, Santa Cruz, CA, 95060, USA
| | - Steven J Bograd
- NOAA Southwest Fisheries Science Center, Environmental Research Division, 99 Pacific St. #255A, Monterey, CA, 93940, USA
| | - Justin S Brashares
- Department of Environmental Science, Policy, and Management, University of California Berkeley, 130 Mulford Hall #3114, Berkeley, CA, 94720, USA
| | - Patrick W Robinson
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, 115 McAllister Way, Santa Cruz, CA, 95060, USA
| | - Kylie L Scales
- University of the Sunshine Coast, 90 Sippy Downs Drive, Sippy Downs, Qld, Australia
| | - Daniel E Crocker
- Department of Biology, Sonoma State University, 1801 East Cotati Avenue, Rohnert Park, CA, 94928, USA
| | - Daniel P Costa
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, 115 McAllister Way, Santa Cruz, CA, 95060, USA
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50
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Extensive Core Microbiome in Drone-Captured Whale Blow Supports a Framework for Health Monitoring. mSystems 2017; 2:mSystems00119-17. [PMID: 29034331 PMCID: PMC5634792 DOI: 10.1128/msystems.00119-17] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 09/13/2017] [Indexed: 01/21/2023] Open
Abstract
The pulmonary system is a common site for bacterial infections in cetaceans, but very little is known about their respiratory microbiome. We used a small, unmanned hexacopter to collect exhaled breath condensate (blow) from two geographically distinct populations of apparently healthy humpback whales (Megaptera novaeangliae), sampled in the Massachusetts coastal waters off Cape Cod (n = 17) and coastal waters around Vancouver Island (n = 9). Bacterial and archaeal small-subunit rRNA genes were amplified and sequenced from blow samples, including many of sparse volume, as well as seawater and other controls, to characterize the associated microbial community. The blow microbiomes were distinct from the seawater microbiomes and included 25 phylogenetically diverse bacteria common to all sampled whales. This core assemblage comprised on average 36% of the microbiome, making it one of the more consistent animal microbiomes studied to date. The closest phylogenetic relatives of 20 of these core microbes were previously detected in marine mammals, suggesting that this core microbiome assemblage is specialized for marine mammals and may indicate a healthy, noninfected pulmonary system. Pathogen screening was conducted on the microbiomes at the genus level, which showed that all blow and few seawater microbiomes contained relatives of bacterial pathogens; no known cetacean respiratory pathogens were detected in the blow. Overall, the discovery of a shared large core microbiome in humpback whales is an important advancement for health and disease monitoring of this species and of other large whales. IMPORTANCE The conservation and management of large whales rely in part upon health monitoring of individuals and populations, and methods generally necessitate invasive sampling. Here, we used a small, unmanned hexacopter drone to noninvasively fly above humpback whales from two populations, capture their exhaled breath (blow), and examine the associated microbiome. In the first extensive examination of the large-whale blow microbiome, we present surprising results about the discovery of a large core microbiome that was shared across individual whales from geographically separated populations in two ocean basins. We suggest that this core microbiome, in addition to other microbiome characteristics, could be a useful feature for health monitoring of large whales worldwide.
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