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Ni L, Jiang C, Guo Q, Chi H, Fan C, Shi J, Lin N, Liu Z, Chen S. Metabolomics analysis of physicochemical properties associated with freshness degradation in frozen Antarctic krill (Euphausia superba). Food Res Int 2024; 183:114190. [PMID: 38760127 DOI: 10.1016/j.foodres.2024.114190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 02/25/2024] [Accepted: 02/28/2024] [Indexed: 05/19/2024]
Abstract
This study aimed to determine the effect of different frozen temperatures during storage on the quality of Antarctic krill (Euphausia superba) and assess the change at the metabolite level via a combination of physicochemical property analysis, liquid chromatography-tandem mass spectrometry (LC-MS) based non-targeted metabolomics profiling. Regarding samples stored at -20 °C, the expressions of 7055 metabolites were elevated, while 2313 were downregulated. Lipids and lipid molecules had the highest proportion of differential metabolites. A total of 432 discriminatory metabolites with Kyoto Encyclopedia of Genes and Genomes (KEGG) IDs was obtained. We also observed that the concentrations of differential bitter free amino acids (FAAs) and oxidation products of arachidonic and linoleic acid increased. Moreover, as the storage temperature increased, the freshness, umami, and sweetness components were considerably reduced. Furthermore, results indicated that the color, pH and water-holding capacity (WHC) were potential indicators of quality deterioration, while inosinic acid was a probable biomarker for umami degradation of frozen Antarctic krill. In conclusion, this study demonstrates that storage at lower temperatures can be beneficial for maintaining the freshness of Antarctic krill from macro and micro perspectives.
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Affiliation(s)
- Ling Ni
- East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai 200090, China
| | - Chaojun Jiang
- East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai 200090, China
| | - Quanyou Guo
- East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai 200090, China
| | - Hai Chi
- East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai 200090, China
| | - Chengqi Fan
- East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai 200090, China
| | - Jiangao Shi
- East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai 200090, China
| | - Na Lin
- East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai 200090, China
| | - Zhidong Liu
- East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai 200090, China.
| | - Shengjun Chen
- Key Laboratory of Aquatic Product Processing, Ministry of Agriculture and Rural Affairs, National Research and Development Center for Aquatic Product Processing, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, China.
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2
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Biuw M, Lindstrøm U, Jackson JA, Baines M, Kelly N, McCallum G, Skaret G, Krafft BA. Estimated summer abundance and krill consumption of fin whales throughout the Scotia Sea during the 2018/2019 summer season. Sci Rep 2024; 14:7493. [PMID: 38553485 PMCID: PMC10980806 DOI: 10.1038/s41598-024-57378-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Accepted: 03/18/2024] [Indexed: 04/02/2024] Open
Abstract
Among large cetaceans in the Southern Hemisphere, fin whales were the most heavily exploited in terms of numbers taken during the period of intense industrial whaling. Recent studies suggest that, whilst some humpback whale populations in the Southern Hemisphere appears to have almost completely recovered to their estimated pre-whaling abundance, much less is known about the status of Southern Hemisphere fin whales. Circumpolar estimates in the 1990s suggest an abundance of about 5500 animals south of 60° S, while the IDCR/SOWER-2000 survey for the Scotia Sea and Antarctic Peninsula areas estimated 4670 fin whales within this region in the year 2000. More recent studies in smaller regions indicate higher densities, suggesting that previous estimates are overly conservative and/or that fin whales are undergoing a substantial increase. Here we report findings from a recent multi-vessel single-platform sightings survey carried out as part of the 2019 Area 48 Survey for Antarctic krill. While fin whales were encountered throughout the entire survey area, which covered the majority of CCAMLR Management Area 48, they were particularly abundant around the South Orkney Islands and the eastern Bransfield Strait. Large feeding aggregations were also encountered within the central Scotia Sea between South Orkney Islands and South Georgia. Distance sampling analyses suggest an average fin whale density throughout the Scotia Sea of 0.0256 ( CV = 0.149 ) whales per km2, which agrees well with recent density estimates reported from smaller sub-regions within the Scotia Sea. Design-based distance sampling analyses resulted in an estimated total fin whale abundance of 53,873 (CV = 0.15, 95% CI 40,233-72,138), while a density surface model resulted in a slightly lower estimate of 50,837 (CV: 0.136, 95% CI 38,966-66,324). These estimates are at least an order of magnitude greater than the previous estimate from the same region based on the IDCR/SOWER-2000 data, suggesting that fin whales are undergoing a substantial abundance increase in the South Atlantic. This may have important implications for the assessment of cetacean population trends, but also for CCAMLRs spatial overlap analysis process and efforts to implement a Feedback Management system for Antarctic krill. Our abundance estimate suggests an annual summer krill consumption by fin whales in the Antarctic Peninsula and Scotia Sea area of 7.97 (95% CI 4.94-11.91) million tonnes, which would represent around 20 times the total krill catch taken by the commercial fishery in Area 48 in the same season, or about 12.7% of the 2019 summer krill standing stock estimated from data collected during the same survey. This highlights the crucial importance of including cetacean krill predators in assessment and management efforts for living marine resources in the Southern Ocean, and particularly stresses the urgent need for a re-appraisal of abundance, distribution and ecological role of Southern Hemisphere fin whales.
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Affiliation(s)
- Martin Biuw
- Institute of Marine Research, Fram Centre, P.O. Box 6606, Stakkevollan, NO-9296, Tromsø, Norway.
| | - Ulf Lindstrøm
- Institute of Marine Research, Fram Centre, P.O. Box 6606, Stakkevollan, NO-9296, Tromsø, Norway
| | | | - Mick Baines
- Wildscope, Los Helechos 49, El Cuartón, Tarifa, Cádiz, Spain
| | - Nat Kelly
- Australian Antarctic Division, Department of Agriculture, Water and the Environment, Kingston, TAS, 7050, Australia
| | - George McCallum
- Whalephoto Marine Photography, Grünheiderstrasse 7, 17291, Oberuckersee, Germany
| | - Georg Skaret
- Institute of Marine Research, Nordnes, Bergen, P.O. Box 1870, Norway
| | - Bjørn A Krafft
- Institute of Marine Research, Nordnes, Bergen, P.O. Box 1870, Norway
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3
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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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4
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Åsvestad L, Ahonen H, Menze S, Lowther A, Lindstrøm U, Krafft BA. Seasonal acoustic presence of marine mammals at the South Orkney Islands, Scotia Sea. ROYAL SOCIETY OPEN SCIENCE 2024; 11:230233. [PMID: 38179083 PMCID: PMC10762438 DOI: 10.1098/rsos.230233] [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: 03/03/2023] [Accepted: 11/30/2023] [Indexed: 01/06/2024]
Abstract
Increased knowledge about marine mammal seasonal distribution and species assemblage from the South Orkney Islands waters is needed for the development of management regulations of the commercial fishery for Antarctic krill (Euphausia superba) in this region. Passive acoustic monitoring (PAM) data were collected during the autumn and winter seasons in two consecutive years (2016, 2017), which represented highly contrasting environmental conditions due to the 2016 El Niño event. We explored differences in seasonal patterns in marine mammal acoustic presence between the two years in context of environmental cues and climate variability. Acoustic signals from five baleen whale species, two pinniped species and odontocete species were detected and separated into guilds. Although species diversity remained stable over time, the ice-avoiding and ice-affiliated species dominated before and after the onset of winter, respectively, and thus demonstrating a shift in guild composition related to season. Herein, we provide novel information about local marine mammal species diversity, community structure and residency times in a krill hotspot. Our study also demonstrates the utility of PAM data and its usefulness in providing new insights into the marine mammal habitat use and responses to environmental conditions, which are essential knowledge for the future development of a sustainable fishery management in a changing ecosystem.
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Affiliation(s)
| | | | | | | | - Ulf Lindstrøm
- University of Tromsø, 9037 Tromsø, Norway
- Institute of Marine Research, 9296 Tromsø Norway
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5
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Forcada J, Hoffman JI, Gimenez O, Staniland IJ, Bucktrout P, Wood AG. Ninety years of change, from commercial extinction to recovery, range expansion and decline for Antarctic fur seals at South Georgia. GLOBAL CHANGE BIOLOGY 2023; 29:6867-6887. [PMID: 37839801 DOI: 10.1111/gcb.16947] [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: 07/13/2023] [Revised: 09/04/2023] [Accepted: 09/05/2023] [Indexed: 10/17/2023]
Abstract
With environmental change, understanding how species recover from overharvesting and maintain viable populations is central to ecosystem restoration. Here, we reconstruct 90 years of recovery trajectory of the Antarctic fur seal at South Georgia (S.W. Atlantic), a key indicator species in the krill-based food webs of the Southern Ocean. After being harvested to commercial extinction by 1907, this population rebounded and now constitutes the most abundant otariid in the World. However, its status remains uncertain due to insufficient and conflicting data, and anthropogenic pressures affecting Antarctic krill, an essential staple for millions of fur seals and other predators. Using integrated population models, we estimated simultaneously the long-term abundance for Bird Island, northwest South Georgia, epicentre of recovery of the species after sealing, and population adjustments for survey counts with spatiotemporal applicability. Applied to the latest comprehensive survey data, we estimated the population at South Georgia in 2007-2009 as 3,510,283 fur seals [95% CI: 3,140,548-3,919,604] (ca. 98% of global population), after 40 years of maximum growth and range expansion owing to an abundant krill supply. At Bird Island, after 50 years of exponential growth followed by 25 years of slow stable growth, the population collapsed in 2009 and has thereafter declined by -7.2% [-5.2, -9.1] per annum, to levels of the 1970s. For the instrumental record, this trajectory correlates with a time-varying relationship between coupled climate and sea surface temperature cycles associated with low regional krill availability, although the effects of increasing krill extraction by commercial fishing and natural competitors remain uncertain. Since 2015, fur seal longevity and recruitment have dropped, sexual maturation has retarded, and population growth is expected to remain mostly negative and highly variable. Our analysis documents the rise and fall of a key Southern Ocean predator over a century of profound environmental and ecosystem change.
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Affiliation(s)
- Jaume Forcada
- British Antarctic Survey, Natural Environment Research Council, UKRI, Cambridge, UK
| | - Joseph I Hoffman
- British Antarctic Survey, Natural Environment Research Council, UKRI, Cambridge, UK
- Department of Animal Behavior, University of Bielefeld, Bielefeld, Germany
| | - Olivier Gimenez
- CEFE, CNRS, Univ Montpellier, EPHE, IRD, Montpellier, France
| | | | - Pete Bucktrout
- British Antarctic Survey, Natural Environment Research Council, UKRI, Cambridge, UK
| | - Andrew G Wood
- British Antarctic Survey, Natural Environment Research Council, UKRI, Cambridge, UK
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6
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Sremba AL, Martin AR, Wilson P, Cypriano-Souza AL, Buss DL, Hart T, Engel MH, Bonatto SL, Rosenbaum H, Collins T, Olavarría C, Archer FI, Steel D, Jackson JA, Baker CS. Diversity of mitochondrial DNA in 3 species of great whales before and after modern whaling. J Hered 2023; 114:587-597. [PMID: 37578073 DOI: 10.1093/jhered/esad048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Accepted: 08/11/2023] [Indexed: 08/15/2023] Open
Abstract
The 20th century commercial whaling industry severely reduced populations of great whales throughout the Southern Hemisphere. The effect of this exploitation on genetic diversity and population structure remains largely undescribed. Here, we compare pre- and post-whaling diversity of mitochondrial DNA (mtDNA) control region sequences for 3 great whales in the South Atlantic, such as the blue, humpback, and fin whale. Pre-whaling diversity is described from mtDNA extracted from bones collected near abandoned whaling stations, primarily from the South Atlantic island of South Georgia. These bones are known to represent the first stage of 20th century whaling and thus pre-whaling diversity of these populations. Post-whaling diversity is described from previously published studies reporting large-scale sampling of living whales in the Southern Hemisphere. Despite relatively high levels of surviving genetic diversity in the post-whaling populations, we found evidence of a probable loss of mtDNA lineages in all 3 species. This is evidenced by the detection of a large number of haplotypes found in the pre-whaling samples that are not present in the post-whaling samples. A rarefaction analysis further supports a loss of haplotypes in the South Atlantic humpback and Antarctic blue whale populations. The bones from former whaling stations in the South Atlantic represent a remarkable molecular archive for further investigation of the decline and ongoing recovery in the great whales of the Southern Hemisphere.
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Affiliation(s)
- Angela L Sremba
- Cooperative Institute for Marine Ecosystem and Resource Studies, Oregon State University, Newport, OR, United States
- Marine Mammal Institute, Oregon State University, Newport, OR, United States
| | - Anthony R Martin
- Centre for Remote Environments, University of Dundee, Dundee, United Kingdom
| | | | - Ana Lúcia Cypriano-Souza
- Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil
- Projeto Baleia Jubarte/Instituto Baleia Jubarte Caravelas, Caravelas, BA, Brazil
| | - Danielle L Buss
- British Antarctic Survey, Cambridge, United Kingdom
- Department of Archaeology, University of Cambridge, Cambridge, United Kingdom
| | - Tom Hart
- Department of Zoology, University of Oxford, Oxford, United Kingdom
| | - Marcia H Engel
- Projeto Baleia Jubarte/Instituto Baleia Jubarte Caravelas, Caravelas, BA, Brazil
| | - Sandro L Bonatto
- Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Howard Rosenbaum
- Wildlife Conservation Society, Ocean Giants Program, Bronx, NY, United States
- American Museum of Natural History, Sackler Institute, New York, NY, United States
| | - Tim Collins
- American Museum of Natural History, Sackler Institute, New York, NY, United States
| | - Carlos Olavarría
- Centro de Estudios Avanzados en Zonas Áridas (CEAZA), La Serena, Chile
| | | | - Debbie Steel
- Marine Mammal Institute, Oregon State University, Newport, OR, United States
| | | | - C Scott Baker
- Marine Mammal Institute, Oregon State University, Newport, OR, United States
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7
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Kettemer LE, Ramm T, Broms F, Biuw M, Blanchet MA, Bourgeon S, Dubourg P, Ellendersen ACJ, Horaud M, Kershaw J, Miller PJO, Øien N, Pallin LJ, Rikardsen AH. Don't mind if I do: Arctic humpback whales respond to winter foraging opportunities before migration. ROYAL SOCIETY OPEN SCIENCE 2023; 10:230069. [PMID: 37680501 PMCID: PMC10480701 DOI: 10.1098/rsos.230069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 07/24/2023] [Indexed: 09/09/2023]
Abstract
Migration patterns are fundamentally linked to the spatio-temporal distributions of prey. How migrating animals can respond to changes in their prey's distribution and abundance remains largely unclear. During the last decade, humpback whales (Megaptera novaeangliae) used specific winter foraging sites in fjords of northern Norway, outside of their main summer foraging season, to feed on herring that started overwintering in the area. We used photographic matching to show that whales sighted during summer in the Barents Sea foraged in northern Norway from late October to February, staying up to three months and showing high inter-annual return rates (up to 82%). The number of identified whales in northern Norway totalled 866 individuals by 2019. Genetic sexing and hormone profiling in both areas demonstrate a female bias in northern Norway and suggest higher proportions of pregnancy in northern Norway. This may indicate that the fjord-based winter feeding is important for pregnant females before migration. Our results suggest that humpback whales can respond to foraging opportunities along their migration pathways, in some cases by continuing their feeding season well into winter. This provides an important reminder to implement dynamic ecosystem management that can account for changes in the spatio-temporal distribution of migrating marine mammals.
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Affiliation(s)
- Lisa Elena Kettemer
- UiT—The Arctic University of Norway, Faculty of Bioscience, Fisheries and Economics, 9037 Tromsø, Norway
| | - Theresia Ramm
- UiT—The Arctic University of Norway, Faculty of Bioscience, Fisheries and Economics, 9037 Tromsø, Norway
| | - Fredrik Broms
- North Norwegian Humpback Whale Catalogue (NNHWC), Straumsvegen 238, 9109 Kvaløya, Norway
| | - Martin Biuw
- IMR Institute of Marine Research, FRAM—High North Research Centre for Climate and the Environment, 9007 Tromsø, Norway
| | - Marie-Anne Blanchet
- UiT—The Arctic University of Norway, Faculty of Bioscience, Fisheries and Economics, 9037 Tromsø, Norway
- Norwegian Polar Institute, FRAM—High North Research Centre for Climate and the Environment, 9007 Tromsø, Norway
| | - Sophie Bourgeon
- UiT—The Arctic University of Norway, Faculty of Bioscience, Fisheries and Economics, 9037 Tromsø, Norway
| | - Paul Dubourg
- UiT—The Arctic University of Norway, Faculty of Bioscience, Fisheries and Economics, 9037 Tromsø, Norway
| | - Anna C. J. Ellendersen
- UiT—The Arctic University of Norway, Faculty of Bioscience, Fisheries and Economics, 9037 Tromsø, Norway
| | - Mathilde Horaud
- UiT—The Arctic University of Norway, Faculty of Bioscience, Fisheries and Economics, 9037 Tromsø, Norway
| | - Joanna Kershaw
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, KY16 9ST St Andrews, UK
| | - Patrick J. O. Miller
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, KY16 9ST St Andrews, UK
| | - Nils Øien
- IMR Institute of Marine Research, Nordnes, PO Box 1870, 5817 Bergen, Norway
| | - Logan J. Pallin
- Department of Ecology and Evolutionary Biology, UC Santa Cruz, Santa Cruz, CA 95060, USA
| | - Audun H. Rikardsen
- UiT—The Arctic University of Norway, Faculty of Bioscience, Fisheries and Economics, 9037 Tromsø, Norway
- Norwegian Institute for Nature Research, FRAM—High North Research Centre for Climate and the Environment, 9007 Tromsø, Norway
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8
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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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9
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Ramos EA, Cheeseman T, Marcondes MCC, Olio M, Vogel A, Elwen S, de Melo THM, Facchola C, Cipolotti S, Southerland K, Findlay K, Seyboth E, McCue SA, Kotze PGH, Seakamela SM. Interchange of Southern Hemisphere humpback whales across the South Atlantic Ocean. Sci Rep 2023; 13:4621. [PMID: 36944685 PMCID: PMC10030900 DOI: 10.1038/s41598-023-31358-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Accepted: 03/10/2023] [Indexed: 03/23/2023] Open
Abstract
The cosmopolitan distribution of humpback whales (Megaptera novaeangliae) is largely driven by migrations between winter low-latitude breeding grounds and summer high-latitude feeding grounds. Southern Hemisphere humpback whales faced intensive exploitation during the whaling eras and recently show evidence of population recovery. Gene flow and shared song indicate overlap between the western (A) and eastern (B1, B2) Breeding Stocks in the South Atlantic and Indian Oceans (C1). Here, we investigated photo-identification evidence of population interchange using images of individuals photographed during boat-based tourism and research in Brazil and South Africa from 1989 to 2022. Fluke images were uploaded to Happywhale, a global digital database for marine mammal identification. Six whales were recaptured between countries from 2002 to 2021 with resighting intervals ranging from 0.76 to 12.92 years. Four whales originally photographed off Abrolhos Bank, Brazil were photographed off the Western Cape, South Africa (feeding grounds for B2). Two whales originally photographed off the Western Cape were photographed off Brazil, one traveling to the Eastern Cape in the Southwestern Indian Ocean (a migration corridor for C1) before migrating westward to Brazil. These findings photographically confirm interchange of humpback whales across the South Atlantic and Indian Oceans and the importance of international collaboration to understand population boundaries.
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Affiliation(s)
- Eric Angel Ramos
- Fundación Internacional para la Naturaleza y la Sustentabilidad, Chetumal, Quintana Roo, Mexico.
| | - Ted Cheeseman
- Happywhale, Santa Cruz, CA, USA.
- Marine Ecology Research Centre, Southern Cross University, Lismore, Australia.
| | | | | | | | - Simon Elwen
- Department of Botany and Zoology, Stellenbosch University, Sea Search Research and Conservation, Cape Town, South Africa
| | | | | | | | | | - Ken Findlay
- Faculty of Applied Sciences, Centre for Sustainable Oceans, Cape Peninsula University of Technology, Cape Town, South Africa
| | - Elisa Seyboth
- Faculty of Applied Sciences, Centre for Sustainable Oceans, Cape Peninsula University of Technology, Cape Town, South Africa
| | - Steven A McCue
- Department of Forestry, Fisheries and the Environment, Branch Oceans and Coasts, V& A Waterfront, Cape Town, South Africa
| | - Pieter G H Kotze
- Department of Forestry, Fisheries and the Environment, Branch Oceans and Coasts, V& A Waterfront, Cape Town, South Africa
| | - S Mduduzi Seakamela
- Department of Forestry, Fisheries and the Environment, Branch Oceans and Coasts, V& A Waterfront, Cape Town, South Africa
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10
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Ryan C, Santangelo M, Stephenson B, Branch TA, Wilson EA, Savoca MS. Commercial krill fishing within a foraging supergroup of fin whales in the Southern Ocean. Ecology 2023; 104:e4002. [PMID: 36807151 DOI: 10.1002/ecy.4002] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 12/26/2022] [Accepted: 12/28/2022] [Indexed: 02/22/2023]
Affiliation(s)
| | - Maya Santangelo
- Lindblad Expeditions, Seattle, WA, USA.,Institute for Marine & Antarctic Studies, Hobart, TAS, Australia
| | - Brent Stephenson
- Lindblad Expeditions, Seattle, WA, USA.,Eco-Vista: Photography & Research, Napier, New Zealand
| | - Trevor A Branch
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, WA, USA
| | - Earle A Wilson
- Department of Earth System Science, Stanford University, Stanford, CA, USA
| | - Matthew S Savoca
- Hopkins Marine Station, Stanford University, Pacific Grove, CA, USA
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11
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Dickson I, Butchart SHM, Catalano A, Gibbons D, Jones JPG, Lee‐Brooks K, Oldfield T, Noble D, Paterson S, Roy S, Semelin J, Tinsley‐Marshall P, Trevelyan R, Wauchope H, Wicander S, Sutherland WJ. Introducing a common taxonomy to support learning from failure in conservation. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2023; 37:e13967. [PMID: 35694785 PMCID: PMC10107954 DOI: 10.1111/cobi.13967] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 02/28/2022] [Accepted: 05/30/2022] [Indexed: 06/15/2023]
Abstract
Although some sectors have made significant progress in learning from failure, there is currently limited consensus on how a similar transition could best be achieved in conservation and what is required to facilitate this. One of the key enabling conditions for other sectors is a widely accepted and standardized classification system for identifying and analyzing root causes of failure. We devised a comprehensive taxonomy of root causes of failure affecting conservation projects. To develop this, we solicited examples of real-life conservation efforts that were deemed to have failed in some way, identified their underlying root causes of failure, and used these to develop a generic, 3-tier taxonomy of the ways in which projects fail, at the top of which are 6 overarching cause categories that are further divided into midlevel cause categories and specific root causes. We tested the taxonomy by asking conservation practitioners to use it to classify the causes of failure for conservation efforts they had been involved in. No significant gaps or redundancies were identified during this testing phase. We then analyzed the frequency that particular root causes were encountered by projects within this test sample, which suggested that some root causes were more likely to be encountered than others and that a small number of root causes were more likely to be encountered by projects implementing particular types of conservation action. Our taxonomy could be used to improve identification, analysis, and subsequent learning from failed conservation efforts, address some of the barriers that currently limit the ability of conservation practitioners to learn from failure, and contribute to establishing an effective culture of learning from failure within conservation.
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Affiliation(s)
| | - Stuart H. M. Butchart
- BirdLife InternationalCambridgeUK
- Department of ZoologyCambridge UniversityCambridgeUK
| | | | - David Gibbons
- RSPB Centre for Conservation ScienceRoyal Society for the Protection of Birds, The LodgeSandyUK
| | - Julia P. G. Jones
- College of Environmental Sciences and EngineeringBangor UniversityBangorUK
| | | | | | - David Noble
- The British Trust for Ornithology, The NunneryThetfordUK
| | - Stuart Paterson
- Fauna & Flora InternationalCambridgeUK
- Conservation Leadership ProgrammeCambridgeUK
| | | | | | | | | | - Hannah Wauchope
- Centre for Ecology and Conservation, College of Life and Environmental SciencesUniversity of ExeterPenrynUK
- Conservation Science Group, Department of ZoologyCambridge UniversityCambridgeUK
| | - Sylvia Wicander
- United Nations Environment Programme World Conservation Monitoring CentreCambridgeUK
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12
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Convey P, Hughes KA. Untangling unexpected terrestrial conservation challenges arising from the historical human exploitation of marine mammals in the Atlantic sector of the Southern Ocean. AMBIO 2023; 52:357-375. [PMID: 36048407 PMCID: PMC9755428 DOI: 10.1007/s13280-022-01782-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 07/06/2022] [Accepted: 08/08/2022] [Indexed: 06/15/2023]
Abstract
Intensive human exploitation of the Antarctic fur seal (Arctocephalus gazella) in its primary population centre on sub-Antarctic South Georgia, as well as on other sub-Antarctic islands and parts of the South Shetland Islands, in the eighteenth and nineteenth centuries rapidly brought populations to the brink of extinction. The species has now recovered throughout its original distribution. Non-breeding and yearling seals, almost entirely males, from the South Georgia population now disperse in the summer months far more widely and in higher numbers than there is evidence for taking place in the pre-exploitation era. Large numbers now haul out in coastal terrestrial habitats in the South Orkney Islands and also along the north-east and west coast of the Antarctic Peninsula to at least Marguerite Bay. In these previously less- or non-visited areas, the seals cause levels of damage likely never to have been experienced previously to fragile terrestrial habitats through trampling and over-fertilisation, as well as eutrophication of sensitive freshwater ecosystems. This increased area of summer impact is likely to have further synergies with aspects of regional climate change, including reduction in extent and duration of sea ice permitting seals access farther south, and changes in krill abundance and distribution. The extent and conservation value of terrestrial habitats and biodiversity now threatened by fur seal distribution expansion, and the multiple anthropogenic factors acting in synergy both historically and to the present day, present a new and as yet unaddressed challenge to the agencies charged with ensuring the protection and conservation of Antarctica's unique ecosystems.
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Affiliation(s)
- Peter Convey
- British Antarctic Survey, NERC, High Cross, Madingley Road, Cambridge, CB3 0ET, UK.
- Department of Zoology, University of Johannesburg, Auckland Park 2006, South Africa.
| | - Kevin A Hughes
- British Antarctic Survey, NERC, High Cross, Madingley Road, Cambridge, CB3 0ET, UK
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13
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Linsky JMJ, Dunlop RA, Noad MJ, McMichael LA. A mammalian messenger RNA sex determination method from humpback whale ( Megaptera novaeangliae) blubber biopsies. ROYAL SOCIETY OPEN SCIENCE 2022; 9:220556. [PMID: 36016912 PMCID: PMC9399696 DOI: 10.1098/rsos.220556] [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: 04/27/2022] [Accepted: 08/01/2022] [Indexed: 06/15/2023]
Abstract
The large size of free-ranging mysticetes, such as humpback whales (Megaptera novaeangliae), make capture and release health assessments unfeasible for conservation research. However, individual energetic condition or reproductive health may be assessed from the gene expression of remotely biopsied tissue. To do this, researchers must reliably extract RNA and interpret gene expression measurements within the context of an individual's sex. Here, we outline an RNA extraction protocol from blubber tissue and describe a novel mammalian RNA sex determination method. Our method consists of a duplex reverse transcription-quantitative (real-time) polymerase chain reaction (RT-qPCR) with primer sets for a control gene (ACTB) and the X-chromosome inactivation gene (XIST). Products of each RT-qPCR had distinct melting temperature profiles based on the presence (female) or absence (male) of the XIST transcript. Using high-resolution melt analysis, reactions were sorted into one of two clusters (male/female) based on their melting profiles. We validated the XIST method by comparing results with a standard DNA-based method. With adequate quantities of RNA (minimum of approx. 9 ng µl-1), the XIST sex determination method shows 100% agreement with traditional DNA sex determination. Using the XIST method, future cetacean health studies can interpret gene expression within the context of an individual's sex, all from a single extraction.
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Affiliation(s)
- Jacob M. J. Linsky
- School of Biological Sciences The University of Queensland, St Lucia, Queensland 4072, Australia
- Centre for Marine Science, The University of Queensland, St Lucia, Queensland 4072, Australia
| | - Rebecca A. Dunlop
- School of Biological Sciences The University of Queensland, St Lucia, Queensland 4072, Australia
- Centre for Marine Science, The University of Queensland, St Lucia, Queensland 4072, Australia
| | - Michael J. Noad
- Centre for Marine Science, The University of Queensland, St Lucia, Queensland 4072, Australia
- School of Veterinary Science, The University of Queensland, Gatton, Queensland 4343, Australia
| | - Lee A. McMichael
- School of Veterinary Science, The University of Queensland, Gatton, Queensland 4343, Australia
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14
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Herr H, Viquerat S, Devas F, Lees A, Wells L, Gregory B, Giffords T, Beecham D, Meyer B. Return of large fin whale feeding aggregations to historical whaling grounds in the Southern Ocean. Sci Rep 2022; 12:9458. [PMID: 35798799 PMCID: PMC9262878 DOI: 10.1038/s41598-022-13798-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 05/27/2022] [Indexed: 11/26/2022] Open
Abstract
Fin whales (Balaenoptera physalus quoyi) of the Southern Hemisphere were brought to near extinction by twentieth century industrial whaling. For decades, they had all but disappeared from previously highly frequented feeding grounds in Antarctic waters. Our dedicated surveys now confirm their return to ancestral feeding grounds, gathering at the Antarctic Peninsula in large aggregations to feed. We report on the results of an abundance survey and present the first scientific documentation of large fin whale feeding aggregations at Elephant Island, Antarctica, including the first ever video documentation. We interpret high densities, re-establishment of historical behaviours and the return to ancestral feeding grounds as signs for a recovering population. Recovery of a large whale population has the potential to augment primary productivity at their feeding grounds through the effects of nutrient recycling, known as 'the whale pump'. The recovery of fin whales in that area could thus restore ecosystem functions crucial for atmospheric carbon regulation in the world's most important ocean region for the uptake of anthropogenic CO2.
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Affiliation(s)
- Helena Herr
- Institute of Marine Ecosystem and Fishery Science, Center for Earth System Research and Sustainability, University of Hamburg, Große Elbstraße 133, 22767, Hamburg, Germany. .,Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570, Bremerhaven, Germany.
| | - Sacha Viquerat
- Institute of Marine Ecosystem and Fishery Science, Center for Earth System Research and Sustainability, University of Hamburg, Große Elbstraße 133, 22767, Hamburg, Germany.,Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570, Bremerhaven, Germany
| | - Fredi Devas
- BBC Studios, Natural History Unit, Bridgewaterhouse, Counterslip, Bristol, UK
| | - Abigail Lees
- BBC Studios, Natural History Unit, Bridgewaterhouse, Counterslip, Bristol, UK
| | - Lucy Wells
- BBC Studios, Natural History Unit, Bridgewaterhouse, Counterslip, Bristol, UK
| | - Bertie Gregory
- BBC Studios, Natural History Unit, Bridgewaterhouse, Counterslip, Bristol, UK
| | - Ted Giffords
- BBC Studios, Natural History Unit, Bridgewaterhouse, Counterslip, Bristol, UK
| | - Dan Beecham
- BBC Studios, Natural History Unit, Bridgewaterhouse, Counterslip, Bristol, UK
| | - Bettina Meyer
- Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570, Bremerhaven, Germany.,Institute for Chemistry and Biology of the Marine Environment, Carl von Ossietzky University of Oldenburg, Carl-von-Ossietzky-Straße 9-11, 26111, Oldenburg, Germany.,Helmholtz Institute for Functional Marine Biodiversity at the University of Oldenburg (HIFMB), Ammerländer Heerstraße 231, 26129, Oldenburg, Germany
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15
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Johnston NM, Murphy EJ, Atkinson A, Constable AJ, Cotté C, Cox M, Daly KL, Driscoll R, Flores H, Halfter S, Henschke N, Hill SL, Höfer J, Hunt BPV, Kawaguchi S, Lindsay D, Liszka C, Loeb V, Manno C, Meyer B, Pakhomov EA, Pinkerton MH, Reiss CS, Richerson K, Jr. WOS, Steinberg DK, Swadling KM, Tarling GA, Thorpe SE, Veytia D, Ward P, Weldrick CK, Yang G. Status, Change, and Futures of Zooplankton in the Southern Ocean. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2021.624692] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
In the Southern Ocean, several zooplankton taxonomic groups, euphausiids, copepods, salps and pteropods, are notable because of their biomass and abundance and their roles in maintaining food webs and ecosystem structure and function, including the provision of globally important ecosystem services. These groups are consumers of microbes, primary and secondary producers, and are prey for fishes, cephalopods, seabirds, and marine mammals. In providing the link between microbes, primary production, and higher trophic levels these taxa influence energy flows, biological production and biomass, biogeochemical cycles, carbon flux and food web interactions thereby modulating the structure and functioning of ecosystems. Additionally, Antarctic krill (Euphausia superba) and various fish species are harvested by international fisheries. Global and local drivers of change are expected to affect the dynamics of key zooplankton species, which may have potentially profound and wide-ranging implications for Southern Ocean ecosystems and the services they provide. Here we assess the current understanding of the dominant metazoan zooplankton within the Southern Ocean, including Antarctic krill and other key euphausiid, copepod, salp and pteropod species. We provide a systematic overview of observed and potential future responses of these taxa to a changing Southern Ocean and the functional relationships by which drivers may impact them. To support future ecosystem assessments and conservation and management strategies, we also identify priorities for Southern Ocean zooplankton research.
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16
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Warwick‐Evans V, Kelly N, Dalla Rosa L, Friedlaender A, Hinke JT, Kim JH, Kokubun N, Santora JA, Secchi ER, Seyboth E, Trathan PN. Using seabird and whale distribution models to estimate spatial consumption of krill to inform fishery management. Ecosphere 2022. [DOI: 10.1002/ecs2.4083] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
| | - N. Kelly
- Department of Agriculture, Water and the Environment Australian Antarctic Division Kingston Tasmania Australia
| | - L. Dalla Rosa
- Laboratório de Ecologia e Conservação da Megafauna Marinha Instituto de Oceanografia, Universidade Federal de Rio Grande—FURG Rio Grande Brazil
| | - A. Friedlaender
- Institute for Marine Sciences University of California Santa Cruz Santa Cruz California USA
| | - J. T. Hinke
- Antarctic Ecosystem Research Division, Southwest Fisheries Science Center, National Marine Fisheries Service National Oceanic and Atmospheric Administration La Jolla California USA
| | - J. H. Kim
- Korea Polar Research Institute Incheon South Korea
| | - N. Kokubun
- National Institute of Polar Research Tokyo Japan
| | - J. A. Santora
- Fisheries Ecology Division, Southwest Fisheries Science Center, National Marine Fisheries Service National Oceanic and Atmospheric Administration Santa Cruz California USA
- Department of Applied Mathematics University of California Santa Cruz Santa Cruz California USA
| | - E. R. Secchi
- Laboratório de Ecologia e Conservação da Megafauna Marinha Instituto de Oceanografia, Universidade Federal de Rio Grande—FURG Rio Grande Brazil
| | - E. Seyboth
- Laboratório de Ecologia e Conservação da Megafauna Marinha Instituto de Oceanografia, Universidade Federal de Rio Grande—FURG Rio Grande Brazil
- Centre for Sustainable Oceans, Faculty of Applied Sciences Cape Peninsula University of Cape Town Cape Town South Africa
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17
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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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18
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Estimating the average distribution of Antarctic krill Euphausia superba at the northern Antarctic Peninsula during austral summer and winter. Polar Biol 2022; 45:857-871. [PMID: 35673679 PMCID: PMC9165435 DOI: 10.1007/s00300-022-03039-y] [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: 07/07/2021] [Revised: 03/18/2022] [Accepted: 03/21/2022] [Indexed: 11/03/2022]
Abstract
This study was performed to aid the management of the fishery for Antarctic krill Euphausia superba. Krill are an important component of the Antarctic marine ecosystem, providing a key food source for many marine predators. Additionally, krill are the target of the largest commercial fishery in the Southern Ocean, for which annual catches have been increasing and concentrating in recent years. The krill fishery is managed by the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR), which has endorsed a new management framework that requires information about the spatial distribution and biomass of krill. Here, we use krill density estimates from acoustic surveys and a GAMM framework to model habitat properties associated with high krill biomass during summer and winter in the northern Antarctic Peninsula region, an area important to the commercial fishery. Our models show elevated krill density associated with the shelf break, increased sea surface temperature, moderate chlorophyll-a concentration and increased salinity. During winter, our models show associations with shallow waters (< 1500 m) with low sea-ice concentration, medium sea-level anomaly and medium current speed. Our models predict temporal averages of the distribution and density of krill, which can be used to aid CCAMLR’s revised ecosystem approach to fisheries management. Our models have the potential to help in the spatial and temporal design of future acoustic surveys that would preclude the need for modelled extrapolations. We highlight that the ecosystem approach to fisheries management of krill critically depends upon such field observations at relevant spatial and temporal scales.
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19
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Historical reconstruction of the population dynamics of southern right whales in the southwestern Atlantic Ocean. Sci Rep 2022; 12:3324. [PMID: 35228635 PMCID: PMC8885757 DOI: 10.1038/s41598-022-07370-6] [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: 06/30/2020] [Accepted: 02/17/2022] [Indexed: 11/09/2022] Open
Abstract
Understanding the recovery of whale populations is critical for developing population-management and conservation strategies. The southern right whale (SRW) Eubalena australis was one of the baleen whale species that has experienced centuries of exploitation. We assess here for the first time the population dynamics of the SRW from the southwestern Atlantic Ocean at the regional level to measure numerically the effect of whaling and estimate the population trend and recovery level after depletion. We reconstructed the catch history of whaling for the period 1670-1973 by an extensive review of different literature sources and developed a Bayesian state-space model to estimate the demographic parameters. The population trajectory indicated that the pre-exploitation abundance was close to 58,000 individuals (median = 58,212; 95% CI = 33,329-100,920). The abundance dropped to its lowest abundance levels in the 1830s when fewer than 2,000 individuals remained. The current median population abundance was estimated at 4,742 whales (95% CI = 3,853-6,013), suggesting that the SRW population remains small relative to its pre-exploitation abundance (median depletion P2021 8.7%). We estimated that close to 36% of the SRW population visits the waters of the Península Valdés, the main breeding ground, every year. Our results provide insights into the severity of the whaling operation in the southwestern Atlantic along with the population´s response at low densities, thus contributing to understand the observed differences in population trends over the distributional range of the species worldwide.
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20
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Johannessen JED, Biuw M, Lindstrøm U, Ollus VMS, Martín López LM, Gkikopoulou KC, Oosthuizen WC, Lowther A. Intra-season variations in distribution and abundance of humpback whales in the West Antarctic Peninsula using cruise vessels as opportunistic platforms. Ecol Evol 2022; 12:e8571. [PMID: 35154653 PMCID: PMC8826076 DOI: 10.1002/ece3.8571] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 12/27/2021] [Accepted: 01/06/2022] [Indexed: 11/20/2022] Open
Abstract
Fine-scale knowledge of spatiotemporal dynamics in cetacean distribution and abundance throughout the Western Antarctic Peninsula (WAP) is sparse yet essential for effective ecosystem-based management (EBM). Cruise vessels were used as platforms of opportunity to collect data on the distribution and abundance of humpback whales (Megaptera novaeangliae) during the austral summer of 2019/2020 in a region that is also important for the Antarctic krill (Euphausia superba) fishery, to assess potential spatiotemporal interactions for future use in EBM. Data were analyzed using traditional design-based line transect methodology and spatial density surface hurdle models fitted using a set of physical environmental covariates to estimate the abundance and distribution of whales in the area, and to describe their temporal dynamics. Our results indicate a rapid increase in humpback whale abundance in the Bransfield and Gerlache Straits through December, reaching a stable abundance by mid-January. The distribution of humpback whales appeared to change from a patchier distribution in the northern Gerlache Strait to a significantly concentrated presence in the central Gerlache and southern Bransfield Straits, followed by a subsequent dispersion throughout the area. Abundance estimates agreed well with previous literature, increasing from approximately 7000 individuals in 2000 to a peak of 19,107 in 2020. Based on these estimates, we project a total krill consumption of between 1.4 and 3.7 million tons based on traditional and contemporary literature on per capita krill consumption of whales, respectively. When taken in the context of krill fishery catch data in the study area, we conclude that there is minimal spatiotemporal overlap between humpback whales and fishery activity during our study period of November-January. However, there is potential for significant interaction between the two later in the feeding season, but cetacean survey efforts need to be extended into late season in order to fully characterize this potential overlap.
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Affiliation(s)
| | | | - Ulf Lindstrøm
- Department of Arctic BiologyThe Arctic University of TromsøTromsøNorway
- Institute of Marine ResearchTromsøNorway
| | | | | | - Kalliopi C. Gkikopoulou
- Sea Mammal Research UnitSchool of BiologyScottish Ocean InstituteUniversity of St AndrewsSt AndrewsUK
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21
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The Southern Ocean Exchange: porous boundaries between humpback whale breeding populations in southern polar waters. Sci Rep 2021; 11:23618. [PMID: 34880273 PMCID: PMC8654993 DOI: 10.1038/s41598-021-02612-5] [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: 07/23/2021] [Accepted: 11/17/2021] [Indexed: 11/10/2022] Open
Abstract
Humpback whales (Megaptera novaeangliae) are a cosmopolitan species and perform long annual migrations between low-latitude breeding areas and high-latitude feeding areas. Their breeding populations appear to be spatially and genetically segregated due to long-term, maternally inherited fidelity to natal breeding areas. In the Southern Hemisphere, some humpback whale breeding populations mix in Southern Ocean waters in summer, but very little movement between Pacific and Atlantic waters has been identified to date, suggesting these waters constituted an oceanic boundary between genetically distinct populations. Here, we present new evidence of summer co-occurrence in the West Antarctic Peninsula feeding area of two recovering humpback whale breeding populations from the Atlantic (Brazil) and Pacific (Central and South America). As humpback whale populations recover, observations like this point to the need to revise our perceptions of boundaries between stocks, particularly on high latitude feeding grounds. We suggest that this “Southern Ocean Exchange” may become more frequent as populations recover from commercial whaling and climate change modifies environmental dynamics and humpback whale prey availability.
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22
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Williams R, Lacy RC, Ashe E, Hall A, Plourde S, McQuinn IH, Lesage V. Climate change complicates efforts to ensure survival and recovery of St. Lawrence Estuary beluga. MARINE POLLUTION BULLETIN 2021; 173:113096. [PMID: 34744013 DOI: 10.1016/j.marpolbul.2021.113096] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 10/19/2021] [Accepted: 10/21/2021] [Indexed: 06/13/2023]
Abstract
Decades after a ban on hunting, and despite focused management interventions, the endangered St. Lawrence Estuary (SLE) beluga (Delphinapterus leucas) population has failed to recover. We applied a population viability analysis to simulate the responses of the SLE beluga population across a wide range of variability and uncertainty under current and projected changes in environmental and climate-mediated conditions. Three proximate threats to recovery were explored: ocean noise; contaminants; and prey limitation. Even the most optimistic scenarios failed to achieve the reliable positive population growth needed to meet current recovery targets. Here we show that predicted effects of climate change may be a more significant driver of SLE beluga population dynamics than the proximate threats we considered. Aggressive mitigation of all three proximate threats will be needed to build the population's resilience and allow the population to persist long enough for global actions to mitigate climate change to take effect.
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Affiliation(s)
- Rob Williams
- Oceans Initiative, Pearse Island, Box 193, Alert Bay, BC, V0N 1A0, Canada and 117 E. Louisa Street #135 Seattle, WA 98102 USA.
| | - Robert C Lacy
- Species Conservation Toolkit Initiative, Chicago Zoological Society, Brookfield, IL 60513, USA
| | - Erin Ashe
- Oceans Initiative, Pearse Island, Box 193, Alert Bay, BC, V0N 1A0, Canada and 117 E. Louisa Street #135 Seattle, WA 98102 USA
| | - Ailsa Hall
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St. Andrews, St. Andrews, Fife, Scotland KY16 8LB, UK
| | - Stéphane Plourde
- Maurice Lamontagne Institute, Fisheries and Oceans Canada, Box 1000, 850 Route de la Mer, Mont-Joli, Quebec G5H 3Z4, Canada
| | - Ian H McQuinn
- Maurice Lamontagne Institute, Fisheries and Oceans Canada, Box 1000, 850 Route de la Mer, Mont-Joli, Quebec G5H 3Z4, Canada
| | - Véronique Lesage
- Maurice Lamontagne Institute, Fisheries and Oceans Canada, Box 1000, 850 Route de la Mer, Mont-Joli, Quebec G5H 3Z4, Canada
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23
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Bortolotto GA, Thomas L, Hammond P, Zerbini AN. Alternative method for assessment of southwestern Atlantic humpback whale population status. PLoS One 2021; 16:e0259541. [PMID: 34788309 PMCID: PMC8598017 DOI: 10.1371/journal.pone.0259541] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 10/20/2021] [Indexed: 11/19/2022] Open
Abstract
The population of humpback whales (Megaptera novaeangliae) wintering off eastern South America was exploited by commercial whaling almost to the point of extinction in the mid-twentieth century. Since cessation of whaling in the 1970s it is recovering, but the timing and level of recovery is uncertain. We implemented a Bayesian population dynamics model describing the population's trajectory from 1901 and projecting it to 2040 to revise a previous population status assessment that used Sampling-Importance-Resampling in a Bayesian framework. Using our alternative method for model fitting (Markov chain Monte Carlo), which is more widely accessible to ecologists, we replicate a "base case scenario" to verify the effect on model results, and introduce additional data to update the status assessment. Our approach allowed us to widen the previous informative prior on carrying capacity to better reflect scientific uncertainty around historical population levels. The updated model provided more precise estimates for population sizes over the period considered (1901-2040) and suggests that carrying capacity (K: median 22,882, mean 22,948, 95% credible interval [CI] 22,711-23,545) and minimum population size (N1958: median 305, mean 319, 95% CI 271-444) might be lower than previously estimated (K: median 24,558, mean 25,110, 95% CI 22,791-31,118; N1958: median 503, mean 850, 95% CI 159-3,943). However, posterior 95% credible intervals of parameters in the updated model overlap those of the previous study. Our approach provides an accessible framework for investigating the status of depleted animal populations for which information is available on historical mortality (e.g., catches) and intermittent estimates of population size and/or trend.
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Affiliation(s)
- Guilherme A. Bortolotto
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews, Fife, United Kingdom
- Centre for Research into Ecological and Environment Modelling, University of St Andrews, St Andrews, Fife, United Kingdom
- Instituto Aqualie, Juiz de Fora, Minas Gerais, Brazil
- * E-mail:
| | - Len Thomas
- Centre for Research into Ecological and Environment Modelling, University of St Andrews, St Andrews, Fife, United Kingdom
| | - Philip Hammond
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews, Fife, United Kingdom
- Centre for Research into Ecological and Environment Modelling, University of St Andrews, St Andrews, Fife, United Kingdom
| | - Alexandre N. Zerbini
- Instituto Aqualie, Juiz de Fora, Minas Gerais, Brazil
- Cooperative Institute for Climate, Ocean and Ecosystem Studies, University of Washington and Marine Mammal Laboratory, Alaska Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Seattle, Washington State, United States of America
- Marine Ecology and Telemetry Research, Seabeck, Washington State, United States of America
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24
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Murphy EJ, Johnston NM, Hofmann EE, Phillips RA, Jackson JA, Constable AJ, Henley SF, Melbourne-Thomas J, Trebilco R, Cavanagh RD, Tarling GA, Saunders RA, Barnes DKA, Costa DP, Corney SP, Fraser CI, Höfer J, Hughes KA, Sands CJ, Thorpe SE, Trathan PN, Xavier JC. Global Connectivity of Southern Ocean Ecosystems. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.624451] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Southern Ocean ecosystems are globally important. Processes in the Antarctic atmosphere, cryosphere, and the Southern Ocean directly influence global atmospheric and oceanic systems. Southern Ocean biogeochemistry has also been shown to have global importance. In contrast, ocean ecological processes are often seen as largely separate from the rest of the global system. In this paper, we consider the degree of ecological connectivity at different trophic levels, linking Southern Ocean ecosystems with the global ocean, and their importance not only for the regional ecosystem but also the wider Earth system. We also consider the human system connections, including the role of Southern Ocean ecosystems in supporting society, culture, and economy in many nations, influencing public and political views and hence policy. Rather than Southern Ocean ecosystems being defined by barriers at particular oceanic fronts, ecological changes are gradual due to cross-front exchanges involving oceanographic processes and organism movement. Millions of seabirds and hundreds of thousands of cetaceans move north out of polar waters in the austral autumn interacting in food webs across the Southern Hemisphere, and a few species cross the equator. A number of species migrate into the east and west ocean-basin boundary current and continental shelf regions of the major southern continents. Human travel in and out of the Southern Ocean region includes fisheries, tourism, and scientific vessels in all ocean sectors. These operations arise from many nations, particularly in the Northern Hemisphere, and are important in local communities as well as national economic, scientific, and political activities. As a result of the extensive connectivity, future changes in Southern Ocean ecosystems will have consequences throughout the Earth system, affecting ecosystem services with socio-economic impacts throughout the world. The high level of connectivity also means that changes and policy decisions in marine ecosystems outside the Southern Ocean have consequences for ecosystems south of the Antarctic Polar Front. Knowledge of Southern Ocean ecosystems and their global connectivity is critical for interpreting current change, projecting future change impacts, and identifying integrated strategies for conserving and managing both the Southern Ocean and the broader Earth system.
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25
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McClelland CJ, Denny CK, Larsen TA, Stenhouse GB, Nielsen SE. Landscape estimates of carrying capacity for grizzly bears using nutritional energy supply for management and conservation planning. J Nat Conserv 2021. [DOI: 10.1016/j.jnc.2021.126018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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26
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Grant SM, Waller CL, Morley SA, Barnes DKA, Brasier MJ, Double MC, Griffiths HJ, Hughes KA, Jackson JA, Waluda CM, Constable AJ. Local Drivers of Change in Southern Ocean Ecosystems: Human Activities and Policy Implications. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.624518] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Local drivers are human activities or processes that occur in specific locations, and cause physical or ecological change at the local or regional scale. Here, we consider marine and land-derived pollution, non-indigenous species, tourism and other human visits, exploitation of marine resources, recovery of marine mammals, and coastal change as a result of ice loss, in terms of their historic and current extent, and their interactions with the Southern Ocean environment. We summarise projected increases or decreases in the influence of local drivers, and projected changes to their geographic range, concluding that the influence of non-indigenous species, fishing, and the recovery of marine mammals are predicted to increase in the future across the Southern Ocean. Local drivers can be managed regionally, and we identify existing governance frameworks as part of the Antarctic Treaty System and other instruments which may be employed to mitigate or limit their impacts on Southern Ocean ecosystems.
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27
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Carroll EL, Ott PH, McMillan LF, Galletti Vernazzani B, Neveceralova P, Vermeulen E, Gaggiotti OE, Andriolo A, Baker CS, Bamford C, Best P, Cabrera E, Calderan S, Chirife A, Fewster RM, Flores PAC, Frasier T, Freitas TRO, Groch K, Hulva P, Kennedy A, Leaper R, Leslie MS, Moore M, Oliveira L, Seger J, Stepien EN, Valenzuela LO, Zerbini A, Jackson JA. Genetic Diversity and Connectivity of Southern Right Whales (Eubalaena australis) Found in the Brazil and Chile-Peru Wintering Grounds and the South Georgia (Islas Georgias del Sur) Feeding Ground. J Hered 2021; 111:263-276. [PMID: 32347944 PMCID: PMC7238439 DOI: 10.1093/jhered/esaa010] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Accepted: 04/21/2020] [Indexed: 01/05/2023] Open
Abstract
As species recover from exploitation, continued assessments of connectivity and population structure are warranted to provide information for conservation and management. This is particularly true in species with high dispersal capacity, such as migratory whales, where patterns of connectivity could change rapidly. Here we build on a previous long-term, large-scale collaboration on southern right whales (Eubalaena australis) to combine new (nnew) and published (npub) mitochondrial (mtDNA) and microsatellite genetic data from all major wintering grounds and, uniquely, the South Georgia (Islas Georgias del Sur: SG) feeding grounds. Specifically, we include data from Argentina (npub mtDNA/microsatellite = 208/46), Brazil (nnew mtDNA/microsatellite = 50/50), South Africa (nnew mtDNA/microsatellite = 66/77, npub mtDNA/microsatellite = 350/47), Chile-Peru (nnew mtDNA/microsatellite = 1/1), the Indo-Pacific (npub mtDNA/microsatellite = 769/126), and SG (npub mtDNA/microsatellite = 8/0, nnew mtDNA/microsatellite = 3/11) to investigate the position of previously unstudied habitats in the migratory network: Brazil, SG, and Chile-Peru. These new genetic data show connectivity between Brazil and Argentina, exemplified by weak genetic differentiation and the movement of 1 genetically identified individual between the South American grounds. The single sample from Chile-Peru had an mtDNA haplotype previously only observed in the Indo-Pacific and had a nuclear genotype that appeared admixed between the Indo-Pacific and South Atlantic, based on genetic clustering and assignment algorithms. The SG samples were clearly South Atlantic and were more similar to the South American than the South African wintering grounds. This study highlights how international collaborations are critical to provide context for emerging or recovering regions, like the SG feeding ground, as well as those that remain critically endangered, such as Chile-Peru.
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Affiliation(s)
- Emma L Carroll
- School of Biological Sciences, University of Auckland, Auckland, New Zealand.,School of Biology, University of St Andrews, St Andrews, UK
| | - Paulo H Ott
- Grupo de Estudos de Mamíferos Aquáticos do Rio Grande do Sul, Torres, RS, Brazil.,Universidade Estadual do Rio Grande do Sul, Osório, RS, Brazil
| | - Louise F McMillan
- School of Mathematics and Statistics, Victoria University of Wellington, Wellington, New Zealand
| | | | - 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, Gansbaai, South Africa
| | - Els Vermeulen
- Mammal Research Institute Whale Unit, Department of Zoology and Entomology, University of Pretoria, Hatfield, South Africa
| | | | - Artur Andriolo
- Departamento de Zoologia, Instituto de Ciências Biológicas, Universidade Federal de Juiz de Fora, Campus Universitário, Juiz de Fora, MG, Brazil.,Instituto Aqualie, Juiz de Fora, MG, Brazil
| | - C Scott Baker
- Marine Mammal Institute and Department of Fisheries and Wildlife, Oregon State University, Newport, OR
| | - Connor Bamford
- British Antarctic Survey, Cambridge, UK.,University of Southampton, Southampton, UK
| | | | - Elsa Cabrera
- Centro de Conservación Cetacea-Casilla 19178 Correo 19, Santiago, Chile
| | | | - Andrea Chirife
- Instituto de Ciencias Biomédicas (ICB), Universidad Andrés Bello, Chile
| | - Rachel M Fewster
- Department of Statistics, University of Auckland, Auckland, New Zealand
| | - Paulo A C Flores
- Área de Proteção Ambiental (Environmental Protection Area) Anhatomirim, ICMBio, MMA, Florianópolis, SC, Brazil
| | - Timothy Frasier
- Department of Biology, Saint Mary's University, Halifax, Nova Scotia, Canada
| | - Thales R O Freitas
- Programa de Pós-Graduação em Genética e Biologia Molecular- Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
| | - Karina Groch
- Instituto Australis, Imbituba, Santa Catarina, Brazil
| | - Pavel Hulva
- Department of Zoology, Faculty of Science, Charles University, Prague, Czech Republic.,Department of Biology and Ecology, University of Ostrava, Ostrava, Czech Republic
| | - Amy Kennedy
- Marine Mammal Laboratory, Alaska Fisheries Science Center, National Marine Fisheries Service, NOAA, Seattle, WA
| | | | | | - Michael Moore
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA
| | - Larissa Oliveira
- Universidade Estadual do Rio Grande do Sul, Osório, RS, Brazil.,Laboratório de Ecologia de Mamíferos, Universidade do Vale do Rio dos Sinos, Centro de Ciências da Saúde, Sao Leopoldo, RS, Brazil
| | - Jon Seger
- School of Biological Sciences, University of Utah, Salt Lake City, UT
| | - Emilie N Stepien
- Section of Marine Mammal Research, Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - Luciano O Valenzuela
- School of Biological Sciences, University of Utah, Salt Lake City, UT.,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Laboratorio de Ecología Evolutiva Humana, UNCPBA, Quequén, Buenos Aires Province, Argentina.,Instituto de Conservación de Ballenas, Ciudad Autónoma de Buenos Aires, Argentina
| | - Alexandre Zerbini
- Marine Mammal Laboratory, Alaska Fisheries Science Center, National Marine Fisheries Service, NOAA, Seattle, WA.,Marine Ecology and Telemetry Research, Seabeck, WA.,Joint Institute for the Study of the Atmosphere and Ocean (JISAO), University of Washington, Seattle, WA
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28
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Calderan SV, Leaper RC, Miller BS, Andriolo A, Buss DL, Carroll EL, Kennedy AS, Stepien EN, Jackson JA. Southern right whale vocalizations on foraging grounds in South Georgia. JASA EXPRESS LETTERS 2021; 1:061202. [PMID: 36154373 DOI: 10.1121/10.0005433] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Southern right whale vocalizations were recorded concurrently with visual observations off the sub-Antarctic Island of South Georgia, and the characteristics of these calls were described. Calls were also compared to those of humpback whales at South Georgia, to determine how the two species might reliably be distinguished acoustically. The southern right whale calls measured (which were all upcalls) had lower frequency with peak energy and were mostly shorter in duration than the calls measured from humpback whales. The frequency upsweep and the lack of harmonics of southern right whale calls were also diagnostic characteristics.
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Affiliation(s)
- Susannah V Calderan
- Scottish Association for Marine Science (SAMS), Argyll PA37 1QA, United Kingdom
| | - Russell C Leaper
- International Fund for Animal Welfare, London SE1 8NL, United Kingdom
| | - Brian S Miller
- Australian Antarctic Division, Department of Agriculture, Water and the Environment, Kingston, Tasmania 7050, Australia
| | - Artur Andriolo
- Instituto de Ciências Biológicas, Universidade Federal de Juiz de Fora, Juiz de Fora, Minas Gerais, Brasil
| | - Danielle L Buss
- British Antarctic Survey, NERC, High Cross, Cambridge CB3 0ET, United Kingdom
| | - Emma L Carroll
- School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - Amy S Kennedy
- Cooperative Institute for Climate, Ocean, and Ecosystem Studies (CICOES), University of Washington, Seattle, Washington 98105, USA
| | - Emilie N Stepien
- Department of Bioscience, Aarhus University, Aarhus, Denmark , , , , , , , ,
| | - Jennifer A Jackson
- British Antarctic Survey, NERC, High Cross, Cambridge CB3 0ET, United Kingdom
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29
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Prado-Cabrero A, Nolan JM. Omega-3 nutraceuticals, climate change and threats to the environment: The cases of Antarctic krill and Calanus finmarchicus. AMBIO 2021; 50:1184-1199. [PMID: 33502683 PMCID: PMC8068752 DOI: 10.1007/s13280-020-01472-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 11/20/2020] [Accepted: 12/09/2020] [Indexed: 06/12/2023]
Abstract
The nutraceutical market for EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) is promoting fishing for Euphasia superba (Antarctic krill) in the Southern Ocean and Calanus finmarchicus in Norwegian waters. This industry argues that these species are underexploited, but they are essential in their ecosystems, and climate change is altering their geographical distribution. In this perspective, we advocate the cessation of fishing for these species to produce nutraceuticals with EPA and DHA. We argue that this is possible because, contrary to what this industry promotes, the benefits of these fatty acids only seem significant to specific population groups, and not for the general population. Next, we explain that this is desirable because there is evidence that these fisheries may interact with the impact of climate change. Greener sources of EPA and DHA are already available on the market, and their reasonable use would ease pressure on the Arctic and Antarctic ecosystems.
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Affiliation(s)
- Alfonso Prado-Cabrero
- Nutrition Research Centre Ireland, School of Health Science, Carriganore House, Waterford Institute of Technology, West Campus, Carriganore, Waterford, Ireland
| | - John M. Nolan
- Nutrition Research Centre Ireland, School of Health Science, Carriganore House, Waterford Institute of Technology, West Campus, Carriganore, Waterford, Ireland
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30
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Jackson JA, Kennedy A, Moore M, Andriolo A, Bamford CCG, Calderan S, Cheeseman T, Gittins G, Groch K, Kelly N, Leaper R, Leslie MS, Lurcock S, Miller BS, Richardson J, Rowntree V, Smith P, Stepien E, Stowasser G, Trathan P, Vermeulen E, Zerbini AN, Carroll EL. Have whales returned to a historical hotspot of industrial whaling? The pattern of southern right whale Eubalaena australis recovery at South Georgia. ENDANGER SPECIES RES 2020. [DOI: 10.3354/esr01072] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Around 176500 whales were killed in the sub-Antarctic waters off South Georgia (South Atlantic) between 1904 and 1965. In recent decades, whales have once again become summer visitors, with the southern right whale (SRW) the most commonly reported species until 2011. Here, we assess the distribution, temporal pattern, health status and likely prey of SRWs in these waters, combining observations from a summertime vessel-based expedition to South Georgia, stable isotope data collected from SRWs and putative prey and sightings reports collated by the South Georgia Museum. The expedition used directional acoustics and visual surveys to localise whales and collected skin biopsies and photo-IDs. During 76 h of visual observation effort over 19 expedition days, SRWs were encountered 15 times (~31 individuals). Photo-IDs, combined with publicly contributed images from commercial vessels, were reconciled and quality-controlled to form a catalogue of 6 fully (i.e. both sides) identified SRWs and 26 SRWs identified by either left or right sides. No photo-ID matches were found with lower-latitude calving grounds, but 3 whales had gull lesions supporting a direct link with Península Valdés, Argentina. The isotopic position of SRWs in the South Georgia food web suggests feeding on a combination of copepod and krill species. Opportunistic reports of SRW sightings and associated group sizes remain steady over time, while humpback whales provide a strong contrast, with increased sighting rates and group sizes seen since 2013. These data suggest a plateau in SRWs and an increasing humpback whale presence in South Georgia waters following the cessation of whaling.
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Affiliation(s)
- JA Jackson
- British Antarctic Survey, High Cross, Cambridge CB3 0ET, UK For a full list of affiliations see Supplement 1 at www.int-res.com/articles/suppl/n043p323_supp1.pdf
| | | | | | | | - CCG Bamford
- British Antarctic Survey, High Cross, Cambridge CB3 0ET, UK For a full list of affiliations see Supplement 1 at www.int-res.com/articles/suppl/n043p323_supp1.pdf
| | | | | | | | | | | | | | | | | | | | | | | | | | | | - G Stowasser
- British Antarctic Survey, High Cross, Cambridge CB3 0ET, UK For a full list of affiliations see Supplement 1 at www.int-res.com/articles/suppl/n043p323_supp1.pdf
| | - P Trathan
- British Antarctic Survey, High Cross, Cambridge CB3 0ET, UK For a full list of affiliations see Supplement 1 at www.int-res.com/articles/suppl/n043p323_supp1.pdf
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Bestley S, Ropert-Coudert Y, Bengtson Nash S, Brooks CM, Cotté C, Dewar M, Friedlaender AS, Jackson JA, Labrousse S, Lowther AD, McMahon CR, Phillips RA, Pistorius P, Puskic PS, Reis AODA, Reisinger RR, Santos M, Tarszisz E, Tixier P, Trathan PN, Wege M, Wienecke B. Marine Ecosystem Assessment for the Southern Ocean: Birds and Marine Mammals in a Changing Climate. Front Ecol Evol 2020. [DOI: 10.3389/fevo.2020.566936] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
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Groch KR, Blazquez DNH, Marcondes MCC, Santos J, Colosio A, Díaz Delgado J, Catão-Dias JL. Cetacean morbillivirus in Humpback whales' exhaled breath. Transbound Emerg Dis 2020; 68:1736-1743. [PMID: 33070446 DOI: 10.1111/tbed.13883] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Revised: 10/10/2020] [Accepted: 10/13/2020] [Indexed: 12/21/2022]
Abstract
The humpback whale (HW; Megaptera novaeangliae) population that seasonally resides along the Brazilian coast concentrates in the Abrolhos Bank (Bahia and Espírito Santo states) for breeding during austral winter and spring. Cetacean morbillivirus (CeMV, Paramyxoviridae family) is currently one of the most significant biological threats to cetaceans worldwide with high infection and mortality rates. CeMV is pleiotropic yet it has special tropism for the respiratory, lymphoid and nervous system and is primarily transmitted by the aerogenous route. A new lineage of CeMV, the Guiana dolphin morbillivirus (GDMV), is known to affect cetaceans off Brazil. GDMV was first detected in a Guiana dolphin (Sotalia guianensis) stranded in the Abrolhos Bank region, in 2010. In addition to pathologic examinations on stranded HW, pathogen survey of free-ranging HW may provide valuable insight into the epidemiology of diseases. We hypothesized that HW in the Brazilian breeding ground could be exposed to CeMV. Thus, in the present study, we investigated the presence of CeMV in exhaled breath condensates (EBC) of HW in the Abrolhos Bank. Overall, 73 samples of EBC from 48 groups of HW were collected during the breeding seasons of 2011 (n = 16) and 2012 (n = 57). One sample failed to have the reference gene amplified and was excluded from the study. CeMV was detected by a RT-qPCR method in 2 EBC samples, representing 2 whale groups. Phylogenetic analysis of partial morbillivirus phosphoprotein gene showed 100% homology to GDMV. Our results show that HW in Brazil are infected by CeMV with a relative prevalence of 4.3% (2/47) and demonstrate the suitability of using EBC and RT-qPCR as a non-invasive tool for CeMV survey in free-ranging whales. This pioneer study provides scientific basis for non-invasive CeMV monitoring of HW, suggests HW may play a role in the dynamics of CeMV and raises concern for potential conservation implications for this species.
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Biodiversity Conservation and the Earth System: Mind the Gap. Trends Ecol Evol 2020; 35:919-926. [PMID: 32650985 PMCID: PMC7340394 DOI: 10.1016/j.tree.2020.06.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 06/17/2020] [Accepted: 06/19/2020] [Indexed: 01/18/2023]
Abstract
One of the most striking human impacts on global biodiversity is the ongoing depletion of large vertebrates from terrestrial and aquatic ecosystems. Recent work suggests this loss of megafauna can affect processes at biome or Earth system scales with potentially serious impacts on ecosystem structure and function, ecosystem services, and biogeochemical cycles. We argue that our contemporary approach to biodiversity conservation focuses on spatial scales that are too small to adequately address these impacts. We advocate a new global approach to address this conservation gap, which must enable megafaunal populations to recover to functionally relevant densities. We conclude that re-establishing biome and Earth system functions needs to become an urgent global priority for conservation science and policy.
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Handley JM, Pearmain EJ, Oppel S, Carneiro APB, Hazin C, Phillips RA, Ratcliffe N, Staniland IJ, Clay TA, Hall J, Scheffer A, Fedak M, Boehme L, Pütz K, Belchier M, Boyd IL, Trathan PN, Dias MP. Evaluating the effectiveness of a large multi‐use MPA in protecting Key Biodiversity Areas for marine predators. DIVERS DISTRIB 2020. [DOI: 10.1111/ddi.13041] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Affiliation(s)
| | | | - Steffen Oppel
- RSPB Centre for Conservation Science Royal Society for the Protection of Birds Sandy UK
| | | | | | | | - Norman Ratcliffe
- British Antarctic Survey Natural Environment Research Council Cambridge UK
| | - Iain J. Staniland
- British Antarctic Survey Natural Environment Research Council Cambridge UK
| | - Thomas A. Clay
- School of Environmental Sciences University of Liverpool Liverpool UK
| | - Jonathan Hall
- RSPB Centre for Conservation Science Royal Society for the Protection of Birds Sandy UK
| | - Annette Scheffer
- AS, Marine Stewardship Council London UK
- Okeanos Centre University of the Azores 9901‐862 Horta Portugal
| | | | | | | | - Mark Belchier
- British Antarctic Survey Natural Environment Research Council Cambridge UK
| | | | - Phil N. Trathan
- School of Environmental Sciences University of Liverpool Liverpool UK
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Watters GM, Hinke JT, Reiss CS. Long-term observations from Antarctica demonstrate that mismatched scales of fisheries management and predator-prey interaction lead to erroneous conclusions about precaution. Sci Rep 2020; 10:2314. [PMID: 32047241 PMCID: PMC7012885 DOI: 10.1038/s41598-020-59223-9] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 01/22/2020] [Indexed: 11/11/2022] Open
Abstract
Low catch limits for forage species are often considered to be precautionary measures that can help conserve marine predators. Difficulties measuring the impacts of fisheries removals on dependent predators maintain this perspective, but consideration of the spatio-temporal scales over which forage species, their predators, and fisheries interact can aid assessment of whether low catch limits are as precautionary as presumed. Antarctic krill are targeted by the largest fishery in the Southern Ocean and are key forage for numerous predators. Current krill removals are considered precautionary and have not been previously observed to affect krill-dependent predators, like penguins. Using a hierarchical model and 30+ years of monitoring data, we show that expected penguin performance was reduced when local harvest rates of krill were ≥0.1, and this effect was similar in magnitude to that of poor environmental conditions. With continued climate warming and high local harvest rates, future observations of penguin performance are predicted to be below the long-term mean with a probability of 0.77. Catch limits that are considered precautionary for forage species simply because the limit is a small proportion of the species’ standing biomass may not be precautionary for their predators.
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Affiliation(s)
- George M Watters
- Antarctic Ecosystem Research Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, La Jolla, California, 92037, USA.
| | - Jefferson T Hinke
- Antarctic Ecosystem Research Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, La Jolla, California, 92037, USA
| | - Christian S Reiss
- Antarctic Ecosystem Research Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, La Jolla, California, 92037, USA
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