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Scridel D, Anderle M, Capelli F, Forti A, Bettega C, Alessandrini C, Del Mar Delgado M, Pedrotti L, Partel P, Bogliani G, Pedrini P, Brambilla M. Coping with unpredictable environments: fine-tune foraging microhabitat use in relation to prey availability in an alpine species. Oecologia 2024; 204:845-860. [PMID: 38594420 PMCID: PMC11062978 DOI: 10.1007/s00442-024-05530-1] [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: 08/27/2023] [Accepted: 02/18/2024] [Indexed: 04/11/2024]
Abstract
Microhabitat utilisation holds a pivotal role in shaping a species' ecological dynamics and stands as a crucial concern for effective conservation strategies. Despite its critical importance, microhabitat use has frequently been addressed as static, centering on microhabitat preference. Yet, a dynamic microhabitat use that allows individuals to adjust to fine-scale spatio-temporal prey fluctuations, becomes imperative for species thriving in challenging environments. High-elevation ecosystems, marked by brief growing seasons and distinct abiotic processes like snowmelt, winds, and solar radiation, feature an ephemeral distribution of key resources. To better understand species' strategies in coping with these rapidly changing environments, we delved into the foraging behaviour of the white-winged snowfinch Montifringilla nivalis, an emblematic high-elevation passerine. Through studying microhabitat preferences during breeding while assessing invertebrate prey availability, we unveiled a highly flexible microhabitat use process. Notably, snowfinches exhibited specific microhabitat preferences, favoring grass and melting snow margins, while also responding to local invertebrate availability. This behaviour was particularly evident in snow-associated microhabitats and less pronounced amid tall grass. Moreover, our investigation underscored snowfinches' fidelity to foraging sites, with over half located within 10 m of previous spots. This consistent use prevailed in snow-associated microhabitats and high-prey-density zones. These findings provide the first evidence of dynamic microhabitat use in high-elevation ecosystems and offer further insights into the crucial role of microhabitats for climate-sensitive species. They call for multi-faceted conservation strategies that go beyond identifying and protecting optimal thermal buffering areas in the face of global warming to also encompass locations hosting high invertebrate densities.
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Affiliation(s)
- Davide Scridel
- Department of Life Sciences, University of Trieste, via L. Giorgieri 10, 34127, Trieste, Italy.
- Museo delle Scienze di Trento (MUSE), Ufficio Ricerca e Collezioni, Corso del Lavoro e della Scienza 3, 38122, Trento, Italy.
| | - Matteo Anderle
- Museo delle Scienze di Trento (MUSE), Ufficio Ricerca e Collezioni, Corso del Lavoro e della Scienza 3, 38122, Trento, Italy
- Institute for Alpine Environment, Eurac Research, viale Druso 1, 39100, Drususallee Bolzano/Bozen, Italy
- Department of Environmental Science and Policy, Milan University, via Celoria 26, 20123, Milan, Italy
- Department of Ecology, University of Innsbruck, Sternwartestrasse 15/Technikerstrasse 25, 6020, Innsbruck, Austria
| | - Federico Capelli
- Museo delle Scienze di Trento (MUSE), Ufficio Ricerca e Collezioni, Corso del Lavoro e della Scienza 3, 38122, Trento, Italy
| | - Alessandro Forti
- Museo delle Scienze di Trento (MUSE), Ufficio Ricerca e Collezioni, Corso del Lavoro e della Scienza 3, 38122, Trento, Italy
| | - Chiara Bettega
- Museo delle Scienze di Trento (MUSE), Ufficio Ricerca e Collezioni, Corso del Lavoro e della Scienza 3, 38122, Trento, Italy
| | - Corrado Alessandrini
- Department of Environmental Science and Policy, Milan University, via Celoria 26, 20123, Milan, Italy
| | - Maria Del Mar Delgado
- Biodiversity Research Institute (IMIB, CSIC-Oviedo University, Principality of Asturias), Campus Mieres, Mieres (Asturias), Spain
| | - Luca Pedrotti
- Stelvio National Park, via de Simoni 42, 23032, Bormio, Italy
| | - Piergiovanni Partel
- Ente Parco Naturale Paneveggio-Pale di San Martino, località Castelpietra 2, 38054, Primiero San Martino di Castrozza, Trento, Italy
| | - Giuseppe Bogliani
- Department of Earth and Environmental Sciences, University of Pavia, via Ferrata 1, 27100, Pavia, Italy
| | - Paolo Pedrini
- Museo delle Scienze di Trento (MUSE), Ufficio Ricerca e Collezioni, Corso del Lavoro e della Scienza 3, 38122, Trento, Italy
| | - Mattia Brambilla
- Department of Environmental Science and Policy, Milan University, via Celoria 26, 20123, Milan, Italy
- CRC Ge.S.Di.Mont, Milan University, sede di Edolo, via Morino 8, 25048, Edolo, BS, Italy
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Silva MP, Oliveira C, Prieto R, Silva MA, New L, Pérez‐Jorge S. Bioenergetic modelling of a marine top predator's responses to changes in prey structure. Ecol Evol 2024; 14:e11135. [PMID: 38529024 PMCID: PMC10961477 DOI: 10.1002/ece3.11135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 02/21/2024] [Accepted: 02/28/2024] [Indexed: 03/27/2024] Open
Abstract
Determining how animals allocate energy, and how external factors influence this allocation, is crucial to understand species' life history requirements and response to disturbance. This response is driven in part by individuals' energy balance, prey characteristics, foraging behaviour and energy required for essential functions. We developed a bioenergetic model to estimate minimum foraging success rate (FSR), that is, the lowest possible prey capture rate for individuals to obtain the minimum energy intake needed to meet daily metabolic requirements, for female sperm whale (Physeter macrocephalus). The model was based on whales' theoretical energetic requirements using foraging and prey characteristics from animal-borne tags and stomach contents, respectively. We used this model to simulate two prey structure change scenarios: (1) decrease in mean prey size, thus lower prey energy content and (2) decrease in prey size variability, reducing the variability in prey energy content. We estimate the whales need minimum of ~14% FSR to meet their energetic requirements, and energy intake is more sensitive to energy content changes than a decrease in energy variability. To estimate vulnerability to prey structure changes, we evaluated the compensation level required to meet bioenergetic demands. Considering a minimum 14% FSR, whales would need to increase energy intake by 21% (5-35%) and 49% (27-67%) to compensate for a 15% and 30% decrease in energy content, respectively. For a 30% and 50% decrease in energy variability, whales would need to increase energy intake by 13% (0-23%) and 24% (10-35%) to meet energetic demands, respectively. Our model demonstrates how foraging and prey characteristics can be used to estimate impact of changing prey structure in top predator energetics, which can help inform bottom-up effects on marine ecosystems. We showed the importance of considering different FSR in bioenergetics models, as it can have decisive implications on estimates of energy acquired and affect the conclusions about top predator's vulnerability to possible environmental fluctuations.
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Affiliation(s)
- Mariana P. Silva
- Institute of Marine Sciences – OKEANOSUniversity of the AzoresHortaPortugal
- Institute of Marine Research – IMARHortaPortugal
| | - Cláudia Oliveira
- Institute of Marine Sciences – OKEANOSUniversity of the AzoresHortaPortugal
- Institute of Marine Research – IMARHortaPortugal
| | - Rui Prieto
- Institute of Marine Sciences – OKEANOSUniversity of the AzoresHortaPortugal
- Institute of Marine Research – IMARHortaPortugal
| | - Mónica A. Silva
- Institute of Marine Sciences – OKEANOSUniversity of the AzoresHortaPortugal
- Institute of Marine Research – IMARHortaPortugal
| | - Leslie New
- Department of Mathematics and Computer ScienceUrsinus CollegeCollegevillePennsylvaniaUSA
| | - Sergi Pérez‐Jorge
- Institute of Marine Sciences – OKEANOSUniversity of the AzoresHortaPortugal
- Institute of Marine Research – IMARHortaPortugal
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3
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Fahlbusch JA, Cade DE, Hazen EL, Elliott ML, Saenz BT, Goldbogen JA, Jahncke J. Submesoscale coupling of krill and whales revealed by aggregative Lagrangian coherent structures. Proc Biol Sci 2024; 291:20232461. [PMID: 38378145 PMCID: PMC10878820 DOI: 10.1098/rspb.2023.2461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Accepted: 01/24/2024] [Indexed: 02/22/2024] Open
Abstract
In the marine environment, dynamic physical processes shape biological productivity and predator-prey interactions across multiple scales. Identifying pathways of physical-biological coupling is fundamental to understand the functioning of marine ecosystems yet it is challenging because the interactions are difficult to measure. We examined submesoscale (less than 100 km) surface current features using remote sensing techniques alongside ship-based surveys of krill and baleen whale distributions in the California Current System. We found that aggregative surface current features, represented by Lagrangian coherent structures (LCS) integrated over temporal scales between 2 and 10 days, were associated with increased (a) krill density (up to 2.6 times more dense), (b) baleen whale presence (up to 8.3 times more likely) and (c) subsurface seawater density (at depths up to 10 m). The link between physical oceanography, krill density and krill-predator distributions suggests that LCS are important features that drive the flux of energy and nutrients across trophic levels. Our results may help inform dynamic management strategies aimed at reducing large whales ship strikes and help assess the potential impacts of environmental change on this critical ecosystem.
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Grants
- Funding for ACCESS was provided in part by the Angell Family Foundation, Bently Foundation, Bonnell Cove Foundation, Boring Family Foundation, California Sea Grant, Elinor Patterson Baker Trust, Faucett Catalyst Fund, Firedoll Foundation, Hellman Family Foundation, Moore Family Foundation, National Fish and Wildlife Foundation, Office of National Marine Sanctuaries, Pacific Life Foundation, Resources Legacy Fund, Thelma Doelger Trust for Animals and Point Blue donors.
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Affiliation(s)
- James A. Fahlbusch
- Hopkins Marine Station, Oceans Department, Stanford University, Pacific Grove, CA, USA
- Cascadia Research Collective, Olympia, WA, USA
| | - David E. Cade
- Hopkins Marine Station, Oceans Department, Stanford University, Pacific Grove, CA, USA
| | - Elliott L. Hazen
- Hopkins Marine Station, Oceans Department, Stanford University, Pacific Grove, CA, USA
- Ecosystem Science Division, NOAA Southwest Fisheries Science Center, Monterey, CA, USA
| | - Meredith L. Elliott
- California Current Group, Point Blue Conservation Science, Petaluma, CA, USA
| | | | - Jeremy A. Goldbogen
- Hopkins Marine Station, Oceans Department, Stanford University, Pacific Grove, CA, USA
| | - Jaime Jahncke
- California Current Group, Point Blue Conservation Science, Petaluma, CA, USA
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D'Antonio B, Ferreira LC, Meekan M, Thomson PG, Lieber L, Virtue P, Power C, Pattiaratchi CB, Brierley AS, Sequeira AMM, Thums M. Links between the three-dimensional movements of whale sharks (Rhincodon typus) and the bio-physical environment off a coral reef. MOVEMENT ECOLOGY 2024; 12:10. [PMID: 38297368 PMCID: PMC10829290 DOI: 10.1186/s40462-024-00452-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Accepted: 01/17/2024] [Indexed: 02/02/2024]
Abstract
BACKGROUND Measuring coastal-pelagic prey fields at scales relevant to the movements of marine predators is challenging due to the dynamic and ephemeral nature of these environments. Whale sharks (Rhincodon typus) are thought to aggregate in nearshore tropical waters due to seasonally enhanced foraging opportunities. This implies that the three-dimensional movements of these animals may be associated with bio-physical properties that enhance prey availability. To date, few studies have tested this hypothesis. METHODS Here, we conducted ship-based acoustic surveys, net tows and water column profiling (salinity, temperature, chlorophyll fluorescence) to determine the volumetric density, distribution and community composition of mesozooplankton (predominantly euphausiids and copepods) and oceanographic properties of the water column in the vicinity of whale sharks that were tracked simultaneously using satellite-linked tags at Ningaloo Reef, Western Australia. Generalised linear mixed effect models were used to explore relationships between the 3-dimensional movement behaviours of tracked sharks and surrounding prey fields at a spatial scale of ~ 1 km. RESULTS We identified prey density as a significant driver of horizontal space use, with sharks occupying areas along the reef edge where densities were highest. These areas were characterised by complex bathymetry such as reef gutters and pinnacles. Temperature and salinity profiles revealed a well-mixed water column above the height of the bathymetry (top 40 m of the water column). Regions of stronger stratification were associated with reef gutters and pinnacles that concentrated prey near the seabed, and entrained productivity at local scales (~ 1 km). We found no quantitative relationship between the depth use of sharks and vertical distributions of horizontally averaged prey density. Whale sharks repeatedly dove to depths where spatially averaged prey concentration was highest but did not extend the time spent at these depth layers. CONCLUSIONS Our work reveals previously unrecognized complexity in interactions between whale sharks and their zooplankton prey.
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Affiliation(s)
- Ben D'Antonio
- Oceans Graduate School and the UWA Oceans Institute, The University of Western Australia, 35 Stirling Highway, Perth, WA, 6009, Australia.
- Australian Institute of Marine Science, Indian Ocean Marine Research Centre, University of Western Australia, Perth, WA, Australia.
| | - Luciana C Ferreira
- Australian Institute of Marine Science, Indian Ocean Marine Research Centre, University of Western Australia, Perth, WA, Australia
| | - Mark Meekan
- The Oceans Institute, University of Western Australia, Perth, WA, Australia
| | - Paul G Thomson
- Oceans Graduate School and the UWA Oceans Institute, The University of Western Australia, 35 Stirling Highway, Perth, WA, 6009, Australia
| | - Lilian Lieber
- Marine Biological Association of the United Kingdom, The Laboratory, Citadel Hill, Plymouth, PL1 2PB, UK
| | - Patti Virtue
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS, Australia
- CSIRO Environment, Battery Point, TAS, 7004, Australia
| | - Chloe Power
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS, Australia
| | - Charitha B Pattiaratchi
- Oceans Graduate School and the UWA Oceans Institute, The University of Western Australia, 35 Stirling Highway, Perth, WA, 6009, Australia
| | - Andrew S Brierley
- Pelagic Ecology Research Group, Scottish Oceans Institute, Gatty Marine Laboratory, School of Biology, University of St. Andrews, St Andrews, KY16 8LB, Scotland, UK
| | - Ana M M Sequeira
- The Oceans Institute, University of Western Australia, Perth, WA, Australia
- Research School of Biology, Division of Ecology and Evolution, The Australian National University, 46 Sullivans Creek Road, Canberra, ACT, 2600, Australia
| | - Michele Thums
- Australian Institute of Marine Science, Indian Ocean Marine Research Centre, University of Western Australia, Perth, WA, Australia
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Park JH, Jeong IY, Lee SH, Yoo JC, Lee WS. Changes in Flight Altitude of Black-Tailed Gulls According to Temporal and Environmental Differences. Animals (Basel) 2024; 14:202. [PMID: 38254371 PMCID: PMC10812393 DOI: 10.3390/ani14020202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2023] [Revised: 01/03/2024] [Accepted: 01/03/2024] [Indexed: 01/24/2024] Open
Abstract
In this study, GPS trackers were attached to black-tailed gulls (Larus crassirostris) breeding on five islands in Republic of Korea during April and May 2021, and their flight frequency, behavioral range, and flight altitude were compared during and after the breeding season. During the breeding season, the flight frequency was lowest on Dongman Island (28.7%), where mudflats were distributed nearby, and the range of activity was narrow. In contrast, it tended to be high on Gungsi Island (52%), where the breeding colony was far from land, resulting in a wider range of activity. Although the flight frequency on Dongman Island increased post-breeding season (42.7%), it decreased on other islands. The mean flight altitude during the breeding season was lowest on Dongman Island and highest on Napdaegi Island. In most breeding areas, the mean flight altitude during the post-breeding season was higher than that during the breeding season. However, the lead flight altitude was lower during the non-breeding season compared to that in the breeding season. The home range expanded after the breeding season, with no significant difference in lead time between the breeding and non-breeding seasons. Our findings reveal that black-tailed gulls exhibit varying home ranges and flight altitudes depending on season and geographical location. As generalists, gulls display flexible responses to environmental changes, indicating that flight behavior adapts to the evolving environment over time and across regions.
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Affiliation(s)
- Jong-Hyun Park
- HAE-IN Ecological Research Institute, Busan 48304, Republic of Korea; (J.-H.P.); (I.-Y.J.); (J.-C.Y.)
| | - In-Yong Jeong
- HAE-IN Ecological Research Institute, Busan 48304, Republic of Korea; (J.-H.P.); (I.-Y.J.); (J.-C.Y.)
- Department of Biology, Kyung Hee University, Seoul 02447, Republic of Korea;
| | - Seung-Hae Lee
- Department of Biology, Kyung Hee University, Seoul 02447, Republic of Korea;
| | - Jeong-Chil Yoo
- HAE-IN Ecological Research Institute, Busan 48304, Republic of Korea; (J.-H.P.); (I.-Y.J.); (J.-C.Y.)
- Department of Biology, Kyung Hee University, Seoul 02447, Republic of Korea;
| | - Who-Seung Lee
- Environment Assessment Group, Korea Environment Institute, Sejong 30147, Republic of Korea
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Benoit-Bird KJ. Resource Patchiness as a Resolution to the Food Paradox in the Sea. Am Nat 2024; 203:1-13. [PMID: 38207143 DOI: 10.1086/727473] [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] [Indexed: 01/13/2024]
Abstract
AbstractAverage concentrations of biota in the ocean are low, presenting a critical problem for ocean consumers. High-resolution sampling, however, demonstrates that the ocean is peppered with narrow hot spots of organism activity. To determine whether these resource aggregations could provide a significant solution to the ocean's food paradox, a conceptual graphical model was developed that facilitates comparisons of the role of patchiness in predator-prey interactions across taxa, size scales, and ecosystems. The model predicts that predators are more reliant on aggregated resources for foraging success when the average concentrations of resources is low, the size discrepancy between predator and prey is great, the predator has a high metabolic rate, and/or the predator's foraging time is limited. Size structure differences between marine and terrestrial food webs and a vast disparity in the overall mean density of their resources lead to the conclusion that high-density aggregations of prey are much more important to the survival of oceanic predators than their terrestrial counterparts, shaping the foraging decisions that are available to an individual and setting the stage on which evolutionary pressures can act. Patches of plenty may be rare, but they play an outsized role in behavioral, ecological, and evolutionary processes, particularly in the sea.
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Arostegui MC, Muhling B, Culhane E, Dewar H, Koch SS, Braun CD. A shallow scattering layer structures the energy seascape of an open ocean predator. SCIENCE ADVANCES 2023; 9:eadi8200. [PMID: 37792940 PMCID: PMC10550225 DOI: 10.1126/sciadv.adi8200] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Accepted: 09/01/2023] [Indexed: 10/06/2023]
Abstract
Large predators frequent the open ocean where subsurface light drives visually based trophic interactions. However, we lack knowledge on how predators achieve energy balance in the unproductive open ocean where prey biomass is minimal in well-lit surface waters but high in dim midwaters in the form of scattering layers. We use an interdisciplinary approach to assess how the bioenergetics of scattering layer forays by a model predator vary across biomes. We show that the mean metabolic cost rate of daytime deep foraging dives to scattering layers decreases as much as 26% from coastal to pelagic biomes. The more favorable energetics offshore are enabled by the addition of a shallow scattering layer that, if not present, would otherwise necessitate costlier dives to deeper layers. The unprecedented importance of this shallow scattering layer challenges assumptions that the globally ubiquitous primary deep scattering layer constitutes the only mesopelagic resource regularly targeted by apex predators.
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Affiliation(s)
- Martin C. Arostegui
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA, USA
| | - Barbara Muhling
- Institute of Marine Sciences, University of California, Santa Cruz, Santa Cruz, CA, USA
- Fisheries Resources Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, La Jolla, CA, USA
| | - Emmett Culhane
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA, USA
| | - Heidi Dewar
- Fisheries Resources Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, La Jolla, CA, USA
| | - Stephanie S. Koch
- Department of Biological Sciences, Thomas More University, Crestview Hills, KY, USA
| | - Camrin D. Braun
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA, USA
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Portner EJ, Mowatt-Larssen T, Carretero ACL, Contreras EA, Woodworth-Jefcoats PA, Frable BW, Choy CA. Harnessing a mesopelagic predator as a biological sampler reveals taxonomic and vertical resource partitioning among three poorly known deep-sea fishes. Sci Rep 2023; 13:16078. [PMID: 37752192 PMCID: PMC10522621 DOI: 10.1038/s41598-023-41298-9] [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: 05/03/2023] [Accepted: 08/24/2023] [Indexed: 09/28/2023] Open
Abstract
Pelagic predators are effective biological samplers of midtrophic taxa and are especially useful in deep-sea habitats where relatively mobile taxa frequently avoid observation with conventional methods. We examined specimens sampled from the stomachs of longnose lancetfish, Alepisaurus ferox, to describe the diets and foraging behaviors of three common, but poorly known deep-sea fishes: the hammerjaw (Omosudis lowii, n = 79, 0.3-92 g), juvenile common fangtooth (Anoplogaster cornuta, n = 91, 0.6-22 g), and juvenile Al. ferox (n = 138, 0.3-744 g). Diet overlap among the three species was high, with five shared prey families accounting for 63 ± 11% of the total prey mass per species. However, distinct differences in foraging strategies and prey sizes were evident. Resource partitioning was greatest between An. cornuta that specialized on small (mean = 0.13 ± 0.11 g), shallow-living hyperiid amphipods and O. lowii that specialized on large (mean = 0.97 ± 0.45 g), deep-dwelling hatchetfishes. Juvenile Al. ferox foraged on a high diversity of prey from both shallow and deep habitats. We describe the foraging ecologies of three midtrophic fish competitors and demonstrate the potential for biological samplers to improve our understanding of deep-sea food webs.
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Affiliation(s)
- Elan J Portner
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA.
| | - Tor Mowatt-Larssen
- Virginia Institute of Marine Science, William & Mary, Gloucester Point, VA, USA
| | | | - Emily A Contreras
- Cooperative Institute for Marine and Atmospheric Research, University of Hawai'i, Honolulu, HI, USA
| | - Phoebe A Woodworth-Jefcoats
- Pacific Islands Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Honolulu, HI, USA
| | - Benjamin W Frable
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA
| | - C Anela Choy
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA
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Goetsch C, Gulka J, Friedland KD, Winship AJ, Clerc J, Gilbert A, Goyert HF, Stenhouse IJ, Williams KA, Willmott JR, Rekdahl ML, Rosenbaum HC, Adams EM. Surface and subsurface oceanographic features drive forage fish distributions and aggregations: Implications for prey availability to top predators in the US Northeast Shelf ecosystem. Ecol Evol 2023; 13:e10226. [PMID: 37441097 PMCID: PMC10334121 DOI: 10.1002/ece3.10226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 06/03/2023] [Accepted: 06/07/2023] [Indexed: 07/15/2023] Open
Abstract
Forage fishes are a critical food web link in marine ecosystems, aggregating in a hierarchical patch structure over multiple spatial and temporal scales. Surface-level forage fish aggregations (FFAs) represent a concentrated source of prey available to surface- and shallow-foraging marine predators. Existing survey and analysis methods are often imperfect for studying forage fishes at scales appropriate to foraging predators, making it difficult to quantify predator-prey interactions. In many cases, general distributions of forage fish species are known; however, these may not represent surface-level prey availability to predators. Likewise, we lack an understanding of the oceanographic drivers of spatial patterns of prey aggregation and availability or forage fish community patterns. Specifically, we applied Bayesian joint species distribution models to bottom trawl survey data to assess species- and community-level forage fish distribution patterns across the US Northeast Continental Shelf (NES) ecosystem. Aerial digital surveys gathered data on surface FFAs at two project sites within the NES, which we used in a spatially explicit hierarchical Bayesian model to estimate the abundance and size of surface FFAs. We used these models to examine the oceanographic drivers of forage fish distributions and aggregations. Our results suggest that, in the NES, regions of high community species richness are spatially consistent with regions of high surface FFA abundance. Bathymetric depth drove both patterns, while subsurface features, such as mixed layer depth, primarily influenced aggregation behavior and surface features, such as sea surface temperature, sub-mesoscale eddies, and fronts influenced forage fish diversity. In combination, these models help quantify the availability of forage fishes to marine predators and represent a novel application of spatial models to aerial digital survey data.
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Affiliation(s)
| | - Julia Gulka
- Biodiversity Research InstitutePortlandMaineUSA
| | | | - Arliss J. Winship
- CSS, Inc.FairfaxVirginiaUSA
- National Centers for Coastal Ocean ScienceNOAASilver SpringMarylandUSA
| | - Jeff Clerc
- Normandeau AssociatesGainesvilleFloridaUSA
| | | | - Holly F. Goyert
- CSS, Inc.FairfaxVirginiaUSA
- National Centers for Coastal Ocean ScienceNOAASilver SpringMarylandUSA
| | | | | | | | - Melinda L. Rekdahl
- Wildlife Conservation Society, Ocean Giants Program, Bronx ZooBronxNew YorkUSA
| | - Howard C. Rosenbaum
- Wildlife Conservation Society, Ocean Giants Program, Bronx ZooBronxNew YorkUSA
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The influence of prey availability on behavioral decisions and reproductive success of a central-place forager during lactation. J Theor Biol 2023; 560:111392. [PMID: 36572092 DOI: 10.1016/j.jtbi.2022.111392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 12/14/2022] [Accepted: 12/19/2022] [Indexed: 12/24/2022]
Abstract
Marine central-place foragers are increasingly faced with altered prey landscapes, necessitating predictions of the impact of such changes on behavior, reproductive success, and population dynamics. We used state-dependent behavioral life history theory implemented via Stochastic Dynamic Programming (SDP) to explore the influence of changes in prey distribution and energy gain from foraging on the behavior and reproductive success of a central place forager during lactation. Our work is motivated by northern fur seals (Callorhinus ursinus) because of the ongoing population decline of the Eastern Pacific stock and projected declines in biomass of walleye pollock (Gadus chalcogrammus), a key fur seal prey species in the eastern Bering Sea. We also explored how changes in female and pup metabolic rates, body size, and lactation duration affected model output to provide insight into traits that might experience selective pressure in response to reductions in prey availability. Simulated females adopted a central-place foraging strategy after an initial extended period spent on land (4.7-8.3 days). Trip durations increased as the high energy prey patch moved farther from land or when the energy gain from foraging decreased. Increases in trip duration adversely affected pup growth rates and wean mass despite attempts to compensate by increasing land durations. Metabolic rate changes had the largest impacts on pup wean mass, with reductions in a pup's metabolic rate allowing females to successfully forage at distances of 600+ km from land for up to 15+ days. Our results indicate that without physiological adaptations, a rookery is unlikely to be viable if the primary foraging grounds are 400 km or farther from the rookery. To achieve pup growth rates characteristic of a population experiencing rapid growth, model results indicate the primary foraging grounds need to be <150 km from the rookery.
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Szesciorka AR, Demer DA, Santora JA, Forney KA, Moore JE. Multiscale relationships between humpback whales and forage species hotspots within a large marine ecosystem. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2023; 33:e2794. [PMID: 36484787 DOI: 10.1002/eap.2794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 09/22/2022] [Accepted: 09/27/2022] [Indexed: 06/17/2023]
Abstract
Fluctuations in prey abundance, composition, and distribution can impact predators, and when predators and fisheries target the same species, predators become essential to ecosystem-based management. Because of the difficulty in collecting concomitant predator-prey data at appropriate scales in patchy environments, few studies have identified strong linkages between cetaceans and prey, especially across large geographic areas. During summer 2018, a line-transect survey for cetaceans and coastal pelagic species was conducted over the continental shelf and slope of British Columbia, Canada, and the US West Coast, allowing for a large-scale investigation of predator-prey spatial relationships. We report on a case study of humpback whales (Megaptera novaeangliae) and their primary prey-Pacific herring (Clupea pallasii), northern anchovy (Engraulis mordax), and krill-using generalized additive models to explore the relationships between whale abundance on 10-km transect segments and prey metrics. Prey metrics included direct measures of biomass densities on segments and an original hotspot metric. For each prey species, segments in the upper fifth percentile for biomass density (across all segments) were designated hotspots, and whale counts on a segment were evaluated for their relationship to number of hotspot segments (species-specific and multispecies) within 25, 50, or 100 km. Whale abundance was not strongly related to direct measures of biomass densities, whereas models using hotspot metrics were more effective at describing variation in whale abundance, underscoring that evaluating prey at relevant and measurable scales is critical in patchy, dynamic marine environments. Our analysis highlighted differences in the distribution and prey availability for three humpback whale distinct population segments (DPSs) as defined under the US Endangered Species Act, including threatened and endangered DPSs that forage within the California Current Large Marine Ecosystem. These linkages provide insights into which prey species whales may be targeting in different regions and across multiple scales and, consequently, how climatic variability and anthropogenic risks may differentially impact these distinct predator-prey assemblages. By identifying scale-appropriate prey hotspots that co-occur with humpback whale aggregations, and with targeted, consistent prey sampling and estimations of potential consumption rates by whales, these findings can help inform the conservation and management of humpback whales within an ecosystem-based management framework.
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Affiliation(s)
- Angela R Szesciorka
- Environmental Assessment Services, LLC. Under Contract to NOAA Southwest Fisheries Science Center, Richland, Washington, USA
- Marine Mammal Institute, Hatfield Marine Science Center, Oregon State University, Newport, Oregon, USA
| | - David A Demer
- Fisheries Resources Division, Southwest Fisheries Science Center, NOAA, La Jolla, California, USA
| | - Jarrod A Santora
- Fisheries Ecology Division, Southwest Fisheries Science Center, NOAA, La Jolla, California, USA
- Department of Applied Math, University of California Santa Cruz, Santa Cruz, California, USA
| | - Karin A Forney
- Marine Mammal and Turtle Division, Southwest Fisheries Science Center, NOAA, Moss Landing, California, USA
- Moss Landing Marine Laboratories, San Jose State University, Moss Landing, California, USA
| | - Jeff E Moore
- Marine Mammal and Turtle Division, Southwest Fisheries Science Center, NOAA, La Jolla, California, USA
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12
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Pinti J, Shatley M, Carlisle A, Block BA, Oliver MJ. Using pseudo-absence models to test for environmental selection in marine movement ecology: the importance of sample size and selection strength. MOVEMENT ECOLOGY 2022; 10:60. [PMID: 36581885 PMCID: PMC9798696 DOI: 10.1186/s40462-022-00362-1] [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: 08/26/2022] [Accepted: 12/19/2022] [Indexed: 06/17/2023]
Abstract
BACKGROUND Understanding the selection of environmental conditions by animals requires knowledge of where they are, but also of where they could have been. Presence data can be accurately estimated by direct sampling, sightings, or through electronic tag deployments. However, absence data are harder to determine because absences are challenging to measure in an uncontrolled setting. To address this problem, ecologists have developed different methods for generating pseudo-absence data relying on theoretical movement models. These null models represent the movement of environmentally naive individuals, creating a set of locations that animals could have been if they were not exhibiting environmental selection. METHODS Here, we use four different kinds of null animal movement models-Brownian motion, Lévy walks, Correlated random walks, and Joint correlated random walks to test the ability and power of each of these null movement models to serve as appropriate animal absence models. We use Kolmogorov-Smirnov tests to detect environmental selection using two data sets, one of simulated animal tracks biased towards warmer sea surface temperatures, and one of 57 observed blue shark tracks of unknown sea surface temperature selection. RESULTS The four different types of movement models showed minimal difference in the ability to serve as appropriate null models for environmental selection studies. Selection strength and sample size were more important in detecting true environmental selection. We show that this method can suffer from high false positive rates, especially in the case where animals are not selecting for specific environments. We provide estimates of test accuracy at different sample sizes and selection strengths to avoid false positives when using this method. CONCLUSION We show how movement models can be used to generate pseudo-absences and test for habitat selection in marine organisms. While this approach efficiently detects environmental selection in marine organisms, it cannot detect the underlying mechanisms driving this selection.
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Affiliation(s)
- Jérôme Pinti
- College of Earth, Ocean, and Environment, University of Delaware, Lewes, DE, 19958, USA.
| | - Matthew Shatley
- College of Earth, Ocean, and Environment, University of Delaware, Lewes, DE, 19958, USA
| | - Aaron Carlisle
- College of Earth, Ocean, and Environment, University of Delaware, Lewes, DE, 19958, USA
| | - Barbara A Block
- Hopkins Marine Station, Biology Department, Stanford University, Pacific Grove, CA, 93950, USA
| | - Matthew J Oliver
- College of Earth, Ocean, and Environment, University of Delaware, Lewes, DE, 19958, USA
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13
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Grouping behavior in a Triassic marine apex predator. Curr Biol 2022; 32:5398-5405.e3. [PMID: 36538877 DOI: 10.1016/j.cub.2022.11.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 10/05/2022] [Accepted: 11/02/2022] [Indexed: 12/23/2022]
Abstract
Marine tetrapods occupy important roles in modern marine ecosystems and often gather in large aggregations driven by patchy prey distribution,1,2 social or reproductive behaviors,3,4 or oceanographic factors.5 Here, we show that similar grouping behaviors evolved in an early marine tetrapod lineage, documented by dozens of specimens of the giant ichthyosaur Shonisaurus in the Luning Formation in West Union Canyon, Nevada, USA.6,7 A concentration of at least seven skeletons closely preserved on a single bedding plane received the bulk of previous attention. However, many more specimens are preserved across ∼106 square meters and ∼200 stratigraphic meters of outcrop representing an estimated >105-6 years. Unlike other marine-tetrapod-rich deposits, this assemblage is essentially monotaxic; other vertebrate fossils are exceptionally scarce. Large individuals are disproportionately abundant, with the exception of multiple neonatal or embryonic specimens, indicating an unusual demographic composition apparently lacking intermediate-sized juveniles or subadults. Combined with geological evidence, our data suggest that dense aggregations of Shonisaurus inhabited this moderately deep, low-diversity, tropical marine environment for millennia during the latest Carnian Stage of the Late Triassic Period (237-227 Ma). Thus, philopatric grouping behavior in marine tetrapods, potentially linked to reproductive activity, has an antiquity of at least 230 million years.
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14
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Ryan JP, Benoit‐Bird KJ, Oestreich WK, Leary P, Smith KB, Waluk CM, Cade DE, Fahlbusch JA, Southall BL, Joseph JE, Margolina T, Calambokidis J, DeVogelaere A, Goldbogen JA. Oceanic giants dance to atmospheric rhythms: Ephemeral wind-driven resource tracking by blue whales. Ecol Lett 2022; 25:2435-2447. [PMID: 36197736 PMCID: PMC9827854 DOI: 10.1111/ele.14116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 08/04/2022] [Accepted: 08/14/2022] [Indexed: 01/12/2023]
Abstract
Trophic transfer of energy through marine food webs is strongly influenced by prey aggregation and its exploitation by predators. Rapid aggregation of some marine fish and crustacean forage species during wind-driven coastal upwelling has recently been discovered, motivating the hypothesis that predators of these forage species track the upwelling circulation in which prey aggregation occurs. We examine this hypothesis in the central California Current Ecosystem using integrative observations of upwelling dynamics, forage species' aggregation, and blue whale movement. Directional origins of blue whale calls repeatedly tracked upwelling plume circulation when wind-driven upwelling intensified and aggregation of forage species was heightened. Our findings illustrate a resource tracking strategy by which blue whales may maximize energy gain amid ephemeral foraging opportunities. These findings have implications for the ecology and conservation of diverse predators that are sustained by forage populations whose behaviour is responsive to episodic environmental dynamics.
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Affiliation(s)
- John P. Ryan
- Monterey Bay Aquarium Research InstituteMoss LandingCaliforniaUSA
| | | | - William K. Oestreich
- Monterey Bay Aquarium Research InstituteMoss LandingCaliforniaUSA,Hopkins Marine StationStanford UniversityStanfordCaliforniaUSA
| | - Paul Leary
- Naval Postgraduate SchoolMontereyCaliforniaUSA
| | | | - Chad M. Waluk
- Monterey Bay Aquarium Research InstituteMoss LandingCaliforniaUSA
| | - David E. Cade
- Hopkins Marine StationStanford UniversityStanfordCaliforniaUSA
| | - James A. Fahlbusch
- Hopkins Marine StationStanford UniversityStanfordCaliforniaUSA,Cascadia Research CollectiveOlympiaWashingtonUSA
| | - Brandon L. Southall
- Southall Environmental Associates, Inc.AptosCaliforniaUSA,University of CaliforniaSanta CruzCaliforniaUSA
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15
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Phillips LR, Carroll G, Jonsen I, Harcourt R, Brierley AS, Wilkins A, Cox M. Variability in prey field structure drives inter-annual differences in prey encounter by a marine predator, the little penguin. ROYAL SOCIETY OPEN SCIENCE 2022; 9:220028. [PMID: 36117863 PMCID: PMC9470263 DOI: 10.1098/rsos.220028] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 08/26/2022] [Indexed: 06/15/2023]
Abstract
Understanding how marine predators encounter prey across patchy landscapes remains challenging due to difficulties in measuring the three-dimensional structure of pelagic prey fields at scales relevant to animal movement. We measured at-sea behaviour of a central-place forager, the little penguin (Eudyptula minor), over 5 years (2015-2019) using GPS and dive loggers. We made contemporaneous measurements of the prey field within the penguins' foraging range via boat-based acoustic surveys. We developed a prey encounter index by comparing estimates of acoustic prey density encountered along actual penguin tracks to those encountered along simulated penguin tracks with the same characteristics as real tracks but that moved randomly through the prey field. In most years, penguin tracks encountered prey better than simulated random movements greater than 99% of the time, and penguin dive depths matched peaks in the vertical distribution of prey. However, when prey was unusually sparse and/or deep, penguins had worse than random prey encounter indices, exhibited dives that mismatched depth of maximum prey density, and females had abnormally low body mass (5.3% lower than average). Reductions in prey encounters owing to decreases in the density or accessibility of prey may ultimately lead to reduced fitness and population declines in central-place foraging marine predators.
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Affiliation(s)
| | - Gemma Carroll
- School of Aquatic and Fisheries Sciences, University of Washington, WA, USA
- Resource Ecology and Fisheries Management Division, NOAA Alaska Fisheries Science Center, Seattle, WA USA
| | - Ian Jonsen
- Macquarie University, Sydney, NSW, Australia
| | | | - Andrew S. Brierley
- Pelagic Ecology Research Group, Scottish Oceans Institute, Gatty Marine Laboratory, School of Biology, University of St. Andrews, St Andrews, Scotland KY16 8LB, UK
| | - Adam Wilkins
- Field Friendly, 203 Channel Highway, Kingston, Tasmania 7050, Australia
| | - Martin Cox
- Pelagic Ecology Research Group, Scottish Oceans Institute, Gatty Marine Laboratory, School of Biology, University of St. Andrews, St Andrews, Scotland KY16 8LB, UK
- Australian Antarctic Division, 203 Channel Highway, Kingston, Tasmania 7050, Australia
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16
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Fahlbusch JA, Czapanskiy MF, Calambokidis J, Cade DE, Abrahms B, Hazen EL, Goldbogen JA. Blue whales increase feeding rates at fine-scale ocean features. Proc Biol Sci 2022; 289:20221180. [PMID: 35975432 PMCID: PMC9382224 DOI: 10.1098/rspb.2022.1180] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Marine predators face the challenge of reliably finding prey that is patchily distributed in space and time. Predators make movement decisions at multiple spatial and temporal scales, yet we have a limited understanding of how habitat selection at multiple scales translates into foraging performance. In the ocean, there is mounting evidence that submesoscale (i.e. less than 100 km) processes drive the formation of dense prey patches that should hypothetically provide feeding hot spots and increase predator foraging success. Here, we integrated environmental remote-sensing with high-resolution animal-borne biologging data to evaluate submesoscale surface current features in relation to the habitat selection and foraging performance of blue whales in the California Current System. Our study revealed a consistent functional relationship in which blue whales disproportionately foraged within dynamic aggregative submesoscale features at both the regional and feeding site scales across seasons, regions and years. Moreover, we found that blue whale feeding rates increased in areas with stronger aggregative features, suggesting that these features indicate areas of higher prey density. The use of fine-scale, dynamic features by foraging blue whales underscores the need to take these features into account when designating critical habitat and may help inform strategies to mitigate the impacts of human activities for the species.
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Affiliation(s)
- James A. Fahlbusch
- Hopkins Marine Station, Department of Biology, Stanford University, Pacific Grove, CA, USA,Cascadia Research Collective, Olympia, WA, USA
| | - Max F. Czapanskiy
- Hopkins Marine Station, Department of Biology, Stanford University, Pacific Grove, CA, USA
| | | | - David E. Cade
- Hopkins Marine Station, Department of Biology, Stanford University, Pacific Grove, CA, USA
| | - Briana Abrahms
- Center for Ecosystem Sentinels, Department of Biology, University of Washington, Seattle, WA, USA
| | - Elliott L. Hazen
- Hopkins Marine Station, Department of Biology, Stanford University, Pacific Grove, CA, USA,Environmental Research Division, NOAA Southwest Fisheries Science Center, Monterey, CA, USA
| | - Jeremy A. Goldbogen
- Hopkins Marine Station, Department of Biology, Stanford University, Pacific Grove, CA, USA
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17
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Griffin LP, Casselberry GA, Lowerre-Barbieri SK, Acosta A, Adams AJ, Cooke SJ, Filous A, Friess C, Guttridge TL, Hammerschlag N, Heim V, Morley D, Rider MJ, Skomal GB, Smukall MJ, Danylchuk AJ, Brownscombe JW. Predator-prey landscapes of large sharks and game fishes in the Florida Keys. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2022; 32:e2584. [PMID: 35333436 DOI: 10.1002/eap.2584] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 06/24/2021] [Indexed: 06/14/2023]
Abstract
Interspecific interactions can play an essential role in shaping wildlife populations and communities. To date, assessments of interspecific interactions, and more specifically predator-prey dynamics, in aquatic systems over broad spatial and temporal scales (i.e., hundreds of kilometers and multiple years) are rare due to constraints on our abilities to measure effectively at those scales. We applied new methods to identify space-use overlap and potential predation risk to Atlantic tarpon (Megalops atlanticus) and permit (Trachinotus falcatus) from two known predators, great hammerhead (Sphyrna mokarran) and bull (Carcharhinus leucas) sharks, over a 3-year period using acoustic telemetry in the coastal region of the Florida Keys (USA). By examining spatiotemporal overlap, as well as the timing and order of arrival at specific locations compared to random chance, we show that potential predation risk from great hammerhead and bull sharks to Atlantic tarpon and permit are heterogeneous across the Florida Keys. Additionally, we find that predator encounter rates with these game fishes are elevated at specific locations and times, including a prespawning aggregation site in the case of Atlantic tarpon. Further, using machine learning algorithms, we identify environmental variability in overlap between predators and their potential prey, including location, habitat, time of year, lunar cycle, depth, and water temperature. These predator-prey landscapes provide insights into fundamental ecosystem function and biological conservation, especially in the context of emerging fishery-related depredation issues in coastal marine ecosystems.
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Affiliation(s)
- Lucas P Griffin
- Department of Environmental Conservation, University of Massachusetts Amherst, Amherst, Massachusetts, USA
| | - Grace A Casselberry
- Department of Environmental Conservation, University of Massachusetts Amherst, Amherst, Massachusetts, USA
| | - Susan K Lowerre-Barbieri
- Florida Fish and Wildlife Conservation Commission, Florida Fish and Wildlife Research Institute, St. Petersburg, Florida, USA
| | - Alejandro Acosta
- South Florida Regional Lab, Florida Fish and Wildlife Conservation Commission, Marathon, Florida, USA
| | - Aaron J Adams
- Bonefish & Tarpon Trust, Miami, Florida, USA
- Florida Atlantic University, Harbor Branch Oceanographic Institute, Fort Pierce, Florida, USA
| | - Steven J Cooke
- Department of Biology, Carleton University, Ottawa, Ontario, Canada
| | - Alex Filous
- Department of Environmental Conservation, University of Massachusetts Amherst, Amherst, Massachusetts, USA
| | - Claudia Friess
- Florida Fish and Wildlife Conservation Commission, Florida Fish and Wildlife Research Institute, St. Petersburg, Florida, USA
| | | | - Neil Hammerschlag
- Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, Florida, USA
| | - Vital Heim
- Bimini Biological Field Station Foundation, Bimini, The Bahamas
- Department of Environmental Sciences, Zoology, University of Basel, Basel, Switzerland
| | - Danielle Morley
- Department of Environmental Conservation, University of Massachusetts Amherst, Amherst, Massachusetts, USA
- South Florida Regional Lab, Florida Fish and Wildlife Conservation Commission, Marathon, Florida, USA
| | - Mitchell J Rider
- Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, Florida, USA
| | - Gregory B Skomal
- Massachusetts Division of Marine Fisheries, New Bedford, Massachusetts, USA
| | | | - Andy J Danylchuk
- Department of Environmental Conservation, University of Massachusetts Amherst, Amherst, Massachusetts, USA
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18
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Urmy SS, Cramer AN, Rogers TL, Sullivan‐Stack J, Schmidt M, Stewart SD, Symons CC. When are bacteria really gazelles? Comparing patchy ecologies with dimensionless numbers. Ecol Lett 2022; 25:1323-1341. [PMID: 35315562 PMCID: PMC9545138 DOI: 10.1111/ele.13987] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 01/04/2022] [Accepted: 02/05/2022] [Indexed: 12/01/2022]
Abstract
From micro to planetary scales, spatial heterogeneity-patchiness-is ubiquitous in ecosystems, defining the environments in which organisms move and interact. However, most large-scale models still use spatially averaged 'mean fields' to represent natural populations, while fine-scale spatially explicit models are mostly restricted to particular organisms or systems. In a conceptual paper, Grünbaum (2012, Interface Focus 2: 150-155) introduced a heuristic, based on three dimensionless ratios quantifying movement, reproduction and resource consumption, to characterise patchy ecological interactions and identify when mean-field assumptions are justifiable. We calculated these dimensionless numbers for 33 interactions between consumers and their resource patches in terrestrial, aquatic and aerial environments. Consumers ranged in size from bacteria to whales, and patches lasted from minutes to millennia, with separation scales from mm to hundreds of km. No interactions could be accurately represented by naive mean-field models, though 19 (58%) could be partially simplified by averaging out movement, reproductive or consumption dynamics. Clustering interactions by their non-dimensional ratios revealed several unexpected dynamic similarities. For example, bacterial Pseudoalteromonas exploit nutrient plumes similarly to Mongolian gazelles grazing on ephemeral steppe vegetation. We argue that dimensional analysis is valuable for characterising ecological patchiness and can link widely different systems into a single quantitative framework.
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Affiliation(s)
- Samuel S. Urmy
- Monterey Bay Aquarium Research InstituteMoss LandingCaliforniaUSA
- Present address:
NOAA Alaska Fisheries Science CenterSeattleWashingtonUSA
| | - Alli N. Cramer
- School of the EnvironmentWashington State UniversityPullmanWashingtonUSA
- Present address:
University of Washington Friday Harbor LaboratoriesFriday HarborWashingtonUSA
| | - Tanya L. Rogers
- NOAA Southwest Fisheries Science CenterSanta CruzCaliforniaUSA
| | | | - Marian Schmidt
- Department of MicrobiologyCornell UniversityIthacaNew YorkUSA
| | | | - Celia C. Symons
- Department of Ecology and Evolutionary BiologyUniversity of CaliforniaIrvineCaliforniaUSA
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19
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Arce F, Hindell MA, McMahon CR, Wotherspoon SJ, Guinet C, Harcourt RG, Bestley S. Elephant seal foraging success is enhanced in Antarctic coastal polynyas. Proc Biol Sci 2022; 289:20212452. [PMID: 35078353 PMCID: PMC8790345 DOI: 10.1098/rspb.2021.2452] [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: 11/09/2021] [Accepted: 12/02/2021] [Indexed: 01/28/2023] Open
Abstract
Antarctic polynyas are persistent open water areas which enable early and large seasonal phytoplankton blooms. This high primary productivity, boosted by iron supply from coastal glaciers, attracts organisms from all trophic levels to form a rich and diverse community. How the ecological benefit of polynya productivity is translated to the highest trophic levels remains poorly resolved. We studied 119 southern elephant seals feeding over the Antarctic shelf and demonstrated that: (i) 96% of seals foraging here used polynyas, with individuals spending on average 62% of their time there; (ii) the seals exhibited more area-restricted search behaviour when in polynyas; and (iii) these seals gained more energy (indicated by increased buoyancy from greater fat stores) when inside polynyas. This higher-quality foraging existed even when ice was not present in the study area, indicating that these are important and predictable foraging grounds year-round. Despite these energetic advantages from using polynyas, not all the seals used them extensively. Factors other than food supply may influence an individual's choice in their use of feeding grounds, such as exposure to predation or the probability of being able to return to distant sub-Antarctic breeding sites.
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Affiliation(s)
- Fernando Arce
- Institute for Marine and Antarctic Studies, University of Tasmania, Private Bag 129 Hobart, TAS 7001, Australia
- Australian Antarctic Division, 203 Channel Highway, Kingston, TAS 7050, Australia
| | - Mark A. Hindell
- Institute for Marine and Antarctic Studies, University of Tasmania, Private Bag 129 Hobart, TAS 7001, Australia
| | - Clive R. McMahon
- Institute for Marine and Antarctic Studies, University of Tasmania, Private Bag 129 Hobart, TAS 7001, Australia
- IMOS Animal Tagging, Sydney Institute of Marine Science, Mosman, NSW 2088, Australia
- Department of Biological Sciences, Macquarie University, North Ryde, NSW 2113, Australia
| | - Simon J. Wotherspoon
- Institute for Marine and Antarctic Studies, University of Tasmania, Private Bag 129 Hobart, TAS 7001, Australia
- Australian Antarctic Division, 203 Channel Highway, Kingston, TAS 7050, Australia
| | - Christophe Guinet
- Centre d'Etudes Biologiques de Chizé, CNRS, Villiers en Bois 79360, France
| | - Robert G. Harcourt
- Department of Biological Sciences, Macquarie University, North Ryde, NSW 2113, Australia
| | - Sophie Bestley
- Institute for Marine and Antarctic Studies, University of Tasmania, Private Bag 129 Hobart, TAS 7001, Australia
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20
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Benoit-Bird KJ, Waluk CM. Remote acoustic detection and characterization of fish schooling behavior. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2021; 150:4329. [PMID: 34972277 DOI: 10.1121/10.0007485] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 11/08/2021] [Indexed: 06/14/2023]
Abstract
Many fish species form social aggregations or shoals. Understanding the conditions under which these groups sometimes coordinate their behavior in space and time, or "school," is important for understanding their ecology, their effects on the ecosystem, and effective management of their stocks. An automated approach to isolate acoustic aggregations in echosounder data relative to the local background scattering is introduced. Aggregations were then identified and characterized in a large dataset acquired from an autonomous platform and a research vessel. Fish schools were statistically distinct from other aggregations of fish, with differences in their geometry, frequency response, scattering intensity, and scattering distribution. The statistical distribution of acoustic scattering from fish shoals generally followed a Rayleigh distribution as predicted for a randomly organized aggregation of homogenous scatterers. Within fish schools, however, the distribution was distinct from Rayleigh, showing a consistent pattern with most values at low relative scattering levels followed by a sharp roll-off and long right tail. These differences in distribution provide the ability to remotely observe the polarized, organized behavior that defines schooling, a difficult to observe response to environmental and internal conditions, which has large implications for our understanding and management of schooling fish.
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Affiliation(s)
- Kelly J Benoit-Bird
- Monterey Bay Aquarium Research Institute, 7700 Sandholdt Road, Moss Landing, California 95039, USA
| | - Chad M Waluk
- Monterey Bay Aquarium Research Institute, 7700 Sandholdt Road, Moss Landing, California 95039, USA
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21
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Fine-scale spatial segregation in a pelagic seabird driven by differential use of tidewater glacier fronts. Sci Rep 2021; 11:22109. [PMID: 34764330 PMCID: PMC8586018 DOI: 10.1038/s41598-021-01404-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Accepted: 10/26/2021] [Indexed: 11/23/2022] Open
Abstract
In colonially breeding marine predators, individual movements and colonial segregation are influenced by seascape characteristics. Tidewater glacier fronts are important features of the Arctic seascape and are often described as foraging hotspots. Albeit their documented importance for wildlife, little is known about their structuring effect on Arctic predator movements and space use. In this study, we tested the hypothesis that tidewater glacier fronts can influence marine bird foraging patterns and drive spatial segregation among adjacent colonies. We analysed movements of black-legged kittiwakes (Rissa tridactyla) in a glacial fjord by tracking breeding individuals from five colonies. Although breeding kittiwakes were observed to travel up to ca. 280 km from the colony, individuals were more likely to use glacier fronts located closer to their colony and rarely used glacier fronts located farther away than 18 km. Such variation in the use of glacier fronts created fine-scale spatial segregation among the four closest (ca. 7 km distance on average) kittiwake colonies. Overall, our results support the hypothesis that spatially predictable foraging patches like glacier fronts can have strong structuring effects on predator movements and can modulate the magnitude of intercolonial spatial segregation in central-place foragers.
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22
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Gallagher CA, Chimienti M, Grimm V, Nabe-Nielsen J. Energy-mediated responses to changing prey size and distribution in marine top predator movements and population dynamics. J Anim Ecol 2021; 91:241-254. [PMID: 34739086 DOI: 10.1111/1365-2656.13627] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Accepted: 10/27/2021] [Indexed: 11/26/2022]
Abstract
Climate change is modifying the structure of marine ecosystems, including that of fish communities. Alterations in abiotic and biotic conditions can decrease fish size and change community spatial arrangement, ultimately impacting predator species which rely on these communities. To conserve predators and understand the drivers of observed changes in their population dynamics, we must advance our understanding of how shifting environmental conditions can impact populations by limiting food available to individuals. To investigate the impacts of changing fish size and spatial aggregation on a top predator population, we applied an existing agent-based model parameterized for harbour porpoises Phocoena phocoena which represents animal energetics and movements in high detail. We used this framework to quantify the impacts of shifting prey size and spatial aggregation on porpoise movement, space use, energetics and population dynamics. Simulated individuals were more likely to switch from area-restricted search to transit behaviour with increasing prey size, particularly when starving, due to elevated resource competition. In simulations with highly aggregated prey, higher prey encounter rates counteracted resource competition, resulting in no impacts of prey spatial aggregation on movement behaviour. Reduced energy intake with decreasing prey size and aggregation level caused population decline, with a 15% decrease in fish length resulting in total population collapse Increasing prey consumption rates by 42.8 ± 4.5% could offset population declines; however, this increase was 21.3 ± 12.7% higher than needed to account for changes in total energy availability alone. This suggests that animals in realistic seascapes require additional energy to locate smaller prey which should be considered when assessing the impacts of decreased energy availability. Changes in prey size and aggregation influenced movements and population dynamics of simulated harbour porpoises, revealing that climate-induced changes in prey structure, not only prey abundance, may threaten predator populations. We demonstrate how a population model with realistic animal movements and process-based energetics can be used to investigate population consequences of shifting food availability, such as those mediated by climate change, and provide a mechanistic explanation for how changes in prey structure can impact energetics, behaviour and ultimately viability of predator populations.
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Affiliation(s)
- Cara A Gallagher
- Department of Ecoscience, Aarhus University, Roskilde, Denmark.,Plant Ecology and Nature Conservation, University of Potsdam, Potsdam, Germany
| | - Marianna Chimienti
- Department of Ecoscience, Aarhus University, Roskilde, Denmark.,Centre d'Etudes Biologiques de Chizé, Villiers-en-Bois, France
| | - Volker Grimm
- Plant Ecology and Nature Conservation, University of Potsdam, Potsdam, Germany.,Department of Ecological Modelling, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
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Martín B, González–Arias J, Vicente–Vírseda JA. Machine learning as a successful approach for predicting complex spatio–temporal patterns in animal species abundance. ANIMAL BIODIVERSITY AND CONSERVATION 2021. [DOI: 10.32800/abc.2021.44.0289] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Our aim was to identify an optimal analytical approach for accurately predicting complex spatio–temporal patterns in animal species distribution. We compared the performance of eight modelling techniques (generalized additive models, regression trees, bagged CART, k–nearest neighbors, stochastic gradient boosting, support vector machines, neural network, and random forest –enhanced form of bootstrap. We also performed extreme gradient boosting –an enhanced form of radiant boosting– to predict spatial patterns in abundance of migrating Balearic shearwaters based on data gathered within eBird. Derived from open–source datasets, proxies of frontal systems and ocean productivity domains that have been previously used to characterize the oceanographic habitats of seabirds were quantified, and then used as predictors in the models. The random
forest model showed the best performance according to the parameters assessed (RMSE value and R2). The correlation between observed and predicted abundance with this model was also considerably high. This study shows that the combination of machine learning techniques and massive data provided by open data sources is a useful approach for identifying the long–term spatial–temporal distribution of species at regional spatial scales.
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24
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Evans R, Lea MA, Hindell MA. Predicting the distribution of foraging seabirds during a period of heightened environmental variability. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2021; 31:e02343. [PMID: 33817895 DOI: 10.1002/eap.2343] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 11/26/2020] [Accepted: 12/06/2020] [Indexed: 06/12/2023]
Abstract
Quantifying the links between the marine environment, prey occurrence, and predator distribution is the first step towards identifying areas of biological importance for marine spatial planning. Events such as marine heatwaves result in an anomalous change in the physical environment, which can lead to shifts in the structure, biomass, and distribution of lower trophic levels. As central-place foragers, seabirds are vulnerable to changes in their foraging grounds during the breeding season. We first quantified spatiotemporal variability in the occurrence and biomass of prey in response to an abrupt change in oceanography as a result of a marine heatwave event. Secondly, using multivariate techniques and machine learning, we investigated if differences in the foraging technique and prey of seabirds resulted in varying responses to changes in prey occurrence and the environment over a 2.5-yr period. We found that the main variables correlated with seabird distribution were also important in structuring the occurrence and biomass of prey; sea-surface temperature (SST), current speed, mixed-layer depth, and bathymetry. Both zooplankton biomass and the occurrence of fish schools exhibited negative relationships with temperature, and temperature was subsequently an important variable in determining seabird distribution. We were able to establish correlations between the distribution of prey and the spatiotemporal distribution of albatross, little penguins and common-diving petrels. We were unable to find a correlation between the distribution of prey and that of short-tailed shearwaters and fairy prions. For high-use coastal areas, the delineation of important foraging regions is essential to balance human use of an area with the needs of marine predators, particularly seabirds.
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Affiliation(s)
- Rhian Evans
- Institute for Marine and Antarctic Studies, University of Tasmania, Private Bag 129, Hobart, Tasmania, 7001, Australia
| | - Mary-Anne Lea
- Institute for Marine and Antarctic Studies, University of Tasmania, Private Bag 129, Hobart, Tasmania, 7001, Australia
- Antarctic Climate and Ecosystems CRC, University of Tasmania, Private Bag 80, Hobart Tasmania, 7001, Australia
| | - Mark A Hindell
- Institute for Marine and Antarctic Studies, University of Tasmania, Private Bag 129, Hobart, Tasmania, 7001, Australia
- Antarctic Climate and Ecosystems CRC, University of Tasmania, Private Bag 80, Hobart Tasmania, 7001, Australia
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25
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Factors affecting the seasonal distribution and biomass of E. pacifica and T. spinifera along the Pacific coast of Canada: A spatiotemporal modelling approach. PLoS One 2021; 16:e0249818. [PMID: 33989288 PMCID: PMC8121349 DOI: 10.1371/journal.pone.0249818] [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: 01/22/2021] [Accepted: 03/26/2021] [Indexed: 11/19/2022] Open
Abstract
Euphausiids are a keystone species in coastal food webs due to their high lipid content and seasonally high biomass. Understanding the habitat and environmental drivers that lead to areas of high biomass, or ‘hotspots’, and their seasonal persistence, will support the identification of important foraging regions for mid- and upper- trophic level predators. We quantify the distribution of hotspots of the two dominant species of euphausiid in the north-east Pacific Ocean: Euphausia pacifica and Thysanoessa spinifera, as well as euphausiid larvae (mixed species). The Canadian coast encompasses the northern California Current Ecosystem and the transition zone to the Alaska current, and is a highly productive region for fisheries, marine mammals, and seabirds. We used spatiotemporal modelling to predict the distribution of these three euphausiid groups in relation to geomorphic and environmental variables during the important spring-summer months (April through September) when euphausiid biomass is highest. We quantified the area, intensity, and persistence of biomass hotspots across months according to specific oceanographic ecosections developed for marine spatial planning purposes. Persistent hotspots of both adult species were predicted to occur along the 200 m depth contour of the continental slope; however, differences were predicted on the shallower Dixon shelf, which was a key area for T. spinifera, and within the Juan de Fuca Eddy system where E. pacifica hotspots occurred. The continental slope along the west coast of Vancouver Island was the only persistent hotspot region common between both adult species and euphausiid larvae. Larval distribution was more correlated with T. spinifera than E. pacifica biomass. Hotspots of adults were more persistent across months than hotspots of euphausiid larvae, which were seasonally patchy. The persistence of biomass hotspots of forage species through periods of low overall biomass could maintain trophic connectivity through perturbation events and increase ecosystem resilience to climate change.
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Forrest JAH, Bouchet PJ, Barley SC, McLennan AG, Meeuwig JJ. True blue: Temporal and spatial stability of pelagic wildlife at a submarine canyon. Ecosphere 2021. [DOI: 10.1002/ecs2.3423] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Affiliation(s)
- J. A. H. Forrest
- School of Biological Sciences University of Western Australia 35 Stirling Hwy Crawley Perth6009Australia
| | - P. J. Bouchet
- School of Biological Sciences University of Western Australia 35 Stirling Hwy Crawley Perth6009Australia
- School of Ocean Sciences Bangor University LL59 5AB Menai Bridge BangorUK
| | - S. C. Barley
- School of Biological Sciences University of Western Australia 35 Stirling Hwy Crawley Perth6009Australia
| | - A. G. McLennan
- School of Biological Sciences University of Western Australia 35 Stirling Hwy Crawley Perth6009Australia
| | - J. J. Meeuwig
- School of Biological Sciences University of Western Australia 35 Stirling Hwy Crawley Perth6009Australia
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27
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Cade DE, Seakamela SM, Findlay KP, Fukunaga J, Kahane‐Rapport SR, Warren JD, Calambokidis J, Fahlbusch JA, Friedlaender AS, Hazen EL, Kotze D, McCue S, Meÿer M, Oestreich WK, Oudejans MG, Wilke C, Goldbogen JA. Predator‐scale spatial analysis of intra‐patch prey distribution reveals the energetic drivers of rorqual whale super‐group formation. Funct Ecol 2021. [DOI: 10.1111/1365-2435.13763] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- David E. Cade
- Hopkins Marine Station Stanford University Pacific Grove CA USA
- Institute of Marine Science University of California, Santa Cruz Santa Cruz CA USA
| | - S. Mduduzi Seakamela
- Department of Environment, Forestry and Fisheries, Branch: Oceans and Coasts, Victoria & Alfred Waterfront Cape Town South Africa
| | - Ken P. Findlay
- Oceans Economy Cape Peninsula University of Technology Cape Town South Africa
- MRI Whale Unit Department of Zoology and Entomology University of Pretoria Hatfield South Africa
| | - Julie Fukunaga
- Hopkins Marine Station Stanford University Pacific Grove CA USA
| | | | - Joseph D. Warren
- School of Marine and Atmospheric Sciences Stony Brook University Southampton NY USA
| | | | - James A. Fahlbusch
- Hopkins Marine Station Stanford University Pacific Grove CA USA
- Cascadia Research Collective Olympia WA USA
| | - Ari S. Friedlaender
- Institute of Marine Science University of California, Santa Cruz Santa Cruz CA USA
| | - Elliott L. Hazen
- Environmental Research Division/Southwest Fisheries Science Center/National Marine Fisheries Service/National Oceanic and Atmospheric Administration Monterey CA USA
| | - Deon Kotze
- Department of Environment, Forestry and Fisheries, Branch: Oceans and Coasts, Victoria & Alfred Waterfront Cape Town South Africa
| | - Steven McCue
- Department of Environment, Forestry and Fisheries, Branch: Oceans and Coasts, Victoria & Alfred Waterfront Cape Town South Africa
| | - Michael Meÿer
- Department of Environment, Forestry and Fisheries, Branch: Oceans and Coasts, Victoria & Alfred Waterfront Cape Town South Africa
| | | | | | - Christopher Wilke
- Department of Environment, Forestry and Fisheries, Branch: Fisheries Management Cape Town South Africa
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Hunt TN, Allen SJ, Bejder L, Parra GJ. Identifying priority habitat for conservation and management of Australian humpback dolphins within a marine protected area. Sci Rep 2020; 10:14366. [PMID: 32873830 PMCID: PMC7463025 DOI: 10.1038/s41598-020-69863-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 06/29/2020] [Indexed: 11/27/2022] Open
Abstract
Increasing human activity along the coast has amplified the extinction risk of inshore delphinids. Informed selection and prioritisation of areas for the conservation of inshore delphinids requires a comprehensive understanding of their distribution and habitat use. In this study, we applied an ensemble species distribution modelling approach, combining results of six modelling algorithms to identify areas of high probability of occurrence of the globally Vulnerable Australian humpback dolphin in northern Ningaloo Marine Park (NMP), north-western Australia. Model outputs were based on sighting data collected during systematic, boat-based surveys between 2013 and 2015, and in relation to various ecogeographic variables. Water depth and distance to coast were identified as the most important variables influencing dolphin presence, with dolphins showing a preference for shallow waters (5-15 m) less than 2 km from the coast. Areas of high probability (> 0.6) of dolphin occurrence were primarily (90%) in multiple use areas where extractive human activities are permitted, and were poorly represented in sanctuary (no-take) zones. This spatial mismatch emphasises the need to reassess for future spatial planning and marine park management plan reviews for NMP. Shallow, coastal waters identified here should be considered priority areas for the conservation of this Vulnerable species.
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Affiliation(s)
- Tim N Hunt
- Cetacean Ecology, Behaviour and Evolution Lab, College of Science and Engineering, Flinders University, Sturt Road, Adelaide, SA, 5042, Australia.
| | - Simon J Allen
- School of Biological Sciences, University of Western Australia, Stirling Highway, Perth, WA, 6109, Australia
- School of Biological Sciences, University of Bristol, Tyndall Avenue, Bristol, BS8 1TQ, UK
- Department of Anthropology, University of Zurich, Rämistrasse 71, 8006, Zurich, Switzerland
| | - Lars Bejder
- Aquatic Megafauna Research Unit, Centre for Sustainable Aquatic Ecosystems, Harry Butler Institute, Murdoch University, South Street, Perth, WA, 6150, Australia
- Marine Mammal Research Program, Hawaii Institute of Marine Biology, University of Hawaii at Manoa, Manoa, HI, 96734, USA
| | - Guido J Parra
- Cetacean Ecology, Behaviour and Evolution Lab, College of Science and Engineering, Flinders University, Sturt Road, Adelaide, SA, 5042, Australia
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29
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Disentangling the biotic and abiotic drivers of emergent migratory behavior using individual-based models. Ecol Modell 2020. [DOI: 10.1016/j.ecolmodel.2020.109225] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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30
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Pérez‐Jorge S, Tobeña M, Prieto R, Vandeperre F, Calmettes B, Lehodey P, Silva MA. Environmental drivers of large‐scale movements of baleen whales in the mid‐North Atlantic Ocean. DIVERS DISTRIB 2020. [DOI: 10.1111/ddi.13038] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Affiliation(s)
- Sergi Pérez‐Jorge
- Okeanos R&D Centre Institute of Marine Research University of the Azores Horta Portugal
- Marine and Environmental Sciences Centre Faculty of Sciences of the University of Lisbon Lisbon Portugal
| | - Marta Tobeña
- Okeanos R&D Centre Institute of Marine Research University of the Azores Horta Portugal
- Marine and Environmental Sciences Centre Faculty of Sciences of the University of Lisbon Lisbon Portugal
| | - Rui Prieto
- Okeanos R&D Centre Institute of Marine Research University of the Azores Horta Portugal
- Marine and Environmental Sciences Centre Faculty of Sciences of the University of Lisbon Lisbon Portugal
| | - Frederic Vandeperre
- Okeanos R&D Centre Institute of Marine Research University of the Azores Horta Portugal
- Marine and Environmental Sciences Centre Faculty of Sciences of the University of Lisbon Lisbon Portugal
| | - Beatriz Calmettes
- Marine Ecosystems Modeling and Monitoring by Satellites CLS Ramonville France
| | - Patrick Lehodey
- Marine Ecosystems Modeling and Monitoring by Satellites CLS Ramonville France
| | - Mónica A. Silva
- Okeanos R&D Centre Institute of Marine Research University of the Azores Horta Portugal
- Marine and Environmental Sciences Centre Faculty of Sciences of the University of Lisbon Lisbon Portugal
- Biology Department Woods Hole Oceanographic Institution Woods Hole MA USA
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31
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Cascão I, Lammers MO, Prieto R, Santos RS, Silva MA. Temporal patterns in acoustic presence and foraging activity of oceanic dolphins at seamounts in the Azores. Sci Rep 2020; 10:3610. [PMID: 32107405 PMCID: PMC7046721 DOI: 10.1038/s41598-020-60441-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Accepted: 02/12/2020] [Indexed: 11/09/2022] Open
Abstract
Several seamounts have been identified as hotspots of marine life in the Azores, acting as feeding stations for top predators, including cetaceans. Passive acoustic monitoring is an efficient tool to study temporal variations in the occurrence and behaviour of vocalizing cetacean species. We deployed bottom-moored Ecological Acoustic Recorders (EARs) to investigate the temporal patterns in acoustic presence and foraging activity of oceanic dolphins at two seamounts (Condor and Gigante) in the Azores. Data were collected in March-May 2008 and April 2010-February 2011. Dolphins were present year round and nearly every day at both seamounts. Foraging signals (buzzes and bray calls) were recorded in >87% of the days dolphin were present. There was a strong diel pattern in dolphin acoustic occurrence and behaviour, with higher detections of foraging and echolocation vocalizations during the night and of social signals during daylight hours. Acoustic data demonstrate that small dolphins consistently use Condor and Gigante seamounts to forage at night. These results suggest that these seamounts likely are important feeding areas for dolphins. This study contributes to a better understanding of the feeding ecology of oceanic dolphins and provides new insights into the role of seamount habitats for top predators.
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Affiliation(s)
- Irma Cascão
- Marine and Environmental Sciences Centre (MARE), Institute of Marine Research (IMAR) and Okeanos R&D Centre, University of the Azores, Rua Frederico Machado 4, 9901-862, Horta, Portugal.
| | - Marc O Lammers
- Hawaiian Islands Humpback Whale National Marine Sanctuary, National Oceanic and Atmospheric Administration (NOAA), Kihei, HI, 96753, USA
- Oceanwide Science Institute (OSI), PO Box 61692, Honolulu, HI, 96744, USA
| | - Rui Prieto
- Marine and Environmental Sciences Centre (MARE), Institute of Marine Research (IMAR) and Okeanos R&D Centre, University of the Azores, Rua Frederico Machado 4, 9901-862, Horta, Portugal
| | - Ricardo S Santos
- Marine and Environmental Sciences Centre (MARE), Institute of Marine Research (IMAR) and Okeanos R&D Centre, University of the Azores, Rua Frederico Machado 4, 9901-862, Horta, Portugal
| | - Mónica A Silva
- Marine and Environmental Sciences Centre (MARE), Institute of Marine Research (IMAR) and Okeanos R&D Centre, University of the Azores, Rua Frederico Machado 4, 9901-862, Horta, Portugal
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA, 02543, USA
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32
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Fritz L, Brost B, Laman E, Luxa K, Sweeney K, Thomason J, Tollit D, Walker W, Zeppelin T. A re-examination of the relationship between Steller sea lion (Eumetopias jubatus) diet and population trend using data from the Aleutian Islands. CAN J ZOOL 2019. [DOI: 10.1139/cjz-2018-0329] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Prey diversity and energy density have been linked to each other and to population trends in many studies of bird and mammal diets. We re-examined these relationships in Steller sea lions (Eumetopias jubatus (Schreber, 1776)) using data collected from the Aleutian Islands, where there has been a strong longitudinal gradient in population trend. Diet diversity and energy density metrics were similar in the western Aleutians, where sea lion counts declined consistently, and in the easternmost Aleutian area, where population trends improved significantly. We compared traditional deterministic diet diversity metrics with diversity scores based on an occupancy model that accounts for differences in sample size and uncertainty in prey group detection. This analysis indicated that there was no significant change in diet diversity over the 23-year study period or any significant differences across the Aleutian Islands. These results are consistent with prey abundance data from nine groundfish bottom trawl surveys conducted over the same period. While diet studies detail what Steller sea lions eat and provide an estimate of their energy intake, they provide only limited information on the energy expended to obtain their food or the consequences of their diet and foraging ecology on individual or population fitness.
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Affiliation(s)
- L. Fritz
- NOAA Fisheries, Alaska Fisheries Science Center, 7600 Sand Point Way NE, Seattle, WA 98115, USA
| | - B. Brost
- NOAA Fisheries, Alaska Fisheries Science Center, 7600 Sand Point Way NE, Seattle, WA 98115, USA
| | - E. Laman
- NOAA Fisheries, Alaska Fisheries Science Center, 7600 Sand Point Way NE, Seattle, WA 98115, USA
| | - K. Luxa
- NOAA Fisheries, Alaska Fisheries Science Center, 7600 Sand Point Way NE, Seattle, WA 98115, USA
| | - K. Sweeney
- NOAA Fisheries, Alaska Fisheries Science Center, 7600 Sand Point Way NE, Seattle, WA 98115, USA
| | - J. Thomason
- NOAA Fisheries, Alaska Fisheries Science Center, 7600 Sand Point Way NE, Seattle, WA 98115, USA
| | - D. Tollit
- SMRU Consulting North America, 55 Water Street, Suite 604, Vancouver, BC V6V 1A1, Canada
| | - W. Walker
- NOAA Fisheries, Alaska Fisheries Science Center, 7600 Sand Point Way NE, Seattle, WA 98115, USA
| | - T. Zeppelin
- NOAA Fisheries, Alaska Fisheries Science Center, 7600 Sand Point Way NE, Seattle, WA 98115, USA
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Waggitt JJ, Cazenave PW, Howarth LM, Evans PGH, van der Kooij J, Hiddink JG. Combined measurements of prey availability explain habitat selection in foraging seabirds. Biol Lett 2019; 14:rsbl.2018.0348. [PMID: 30068542 DOI: 10.1098/rsbl.2018.0348] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2018] [Accepted: 07/10/2018] [Indexed: 11/12/2022] Open
Abstract
Understanding links between habitat characteristics and foraging efficiency helps predict how environmental changes influence populations of top predators. This study examines whether measurements of prey (clupeids) availability varied over stratification gradients, and determined if any of those measurements coincided with aggregations of foraging seabirds (common guillemot Uria aalge and Manx shearwater Puffinus puffinus) in the Celtic Sea, UK. The probability of encountering foraging seabirds was highest around fronts between mixed and stratified water. Prey were denser and shallower in mixed water, whilst encounters with prey were most frequent in stratified water. Therefore, no single measurement of increased prey availability coincided with the location of fronts. However, when considered in combination, overall prey availability was highest in these areas. These results show that top predators may select foraging habitats by trading-off several measurements of prey availability. By showing that top predators select areas where prey switch between behaviours, these results also identify a mechanism that could explain the wider importance of edge habitats for these taxa. As offshore developments (e.g. marine renewable energy installations) change patterns of stratification, their construction may have consequences on the foraging efficiency of seabirds.
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Affiliation(s)
- James J Waggitt
- School of Ocean Sciences, Bangor University, Menai Bridge LL59 5AB, UK
| | | | - Leigh M Howarth
- School of Ocean Sciences, Bangor University, Menai Bridge LL59 5AB, UK
| | - Peter G H Evans
- School of Ocean Sciences, Bangor University, Menai Bridge LL59 5AB, UK.,Sea Watch Foundation, Ewyn Y Don, Bull Bay, Amlwch LL68 9SD, UK
| | - Jeroen van der Kooij
- Centre for Environment, Fisheries and Aquaculture Science, Lowestoft NR33 0HT, UK
| | - Jan G Hiddink
- School of Ocean Sciences, Bangor University, Menai Bridge LL59 5AB, UK
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34
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Using a recreational grade echosounder to quantify the potential prey field of coastal predators. PLoS One 2019; 14:e0217013. [PMID: 31116761 PMCID: PMC6530895 DOI: 10.1371/journal.pone.0217013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Accepted: 05/02/2019] [Indexed: 11/19/2022] Open
Abstract
Quantifying the distribution of prey greatly improves models of habitat use by marine predators and can assist in determining threats to both predators and prey. Small epipelagic fishes are important prey for many predators yet their distribution is difficult to quantify due to extreme patchiness. This study explores the use of recreational grade echosounders (RGE) to quantify school characteristics of epipelagic fish and link their distribution to that of their predators at Banks Peninsula, New Zealand. The hydro-acoustic system was ground-truthed with 259 schools of epipelagic fish. During 2015 and 2016, 136 hydro-acoustic surveys were conducted with concurrent observations of Hector's dolphin (Cephalorhynchus hectori) and little penguins (Eudyptula minor). The relative abundance of the two predator species during surveys was modelled according to the relative abundance of potential prey using generalised additive mixed models. Schools of epipelagic fish were readily detected by the RGE system and were more abundant in summer compared to winter. The models performed well, explaining 43% and 37% of the deviance in relative abundances of dolphins and penguins respectively. This is the first study to link the distribution of Hector's dolphin to that of their epipelagic prey and confirms the utility of RGE in studies of habitat use in marine predators. Limitations associated with a lack of formal acoustic calibration and data formatting can be overcome and would make RGE valuable, inexpensive tools for investigating variability in populations of small pelagic fishes.
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35
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Campbell KJ, Steinfurth A, Underhill LG, Coetzee JC, Dyer BM, Ludynia K, Makhado AB, Merkle D, Rademan J, Upfold L, Sherley RB. Local forage fish abundance influences foraging effort and offspring condition in an endangered marine predator. J Appl Ecol 2019. [DOI: 10.1111/1365-2664.13409] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Kate J. Campbell
- Animal Demography Unit, Department of Biological Sciences University of Cape Town Cape Town South Africa
- Marine Research (MA‐RE) Institute University of Cape Town Cape Town South Africa
| | - Antje Steinfurth
- FitzPatrick Institute of African Ornithology, DST‐NRF Centre of Excellence University of Cape Town Cape Town South Africa
| | - Les G. Underhill
- Animal Demography Unit, Department of Biological Sciences University of Cape Town Cape Town South Africa
| | - Janet C. Coetzee
- Fisheries Management Branch Department of Agriculture, Forestry and Fisheries Cape Town South Africa
| | - Bruce M. Dyer
- Oceans and Coasts Branch Department of Environmental Affairs Cape Town South Africa
| | - Katrin Ludynia
- Marine Research (MA‐RE) Institute University of Cape Town Cape Town South Africa
- Southern African Foundation for the Conservation of Coastal Birds (SANCCOB) Cape Town South Africa
| | - Azwianewi B. Makhado
- FitzPatrick Institute of African Ornithology, DST‐NRF Centre of Excellence University of Cape Town Cape Town South Africa
- Oceans and Coasts Branch Department of Environmental Affairs Cape Town South Africa
| | - Dagmar Merkle
- Fisheries Management Branch Department of Agriculture, Forestry and Fisheries Cape Town South Africa
| | - Johan Rademan
- Fisheries Management Branch Department of Agriculture, Forestry and Fisheries Cape Town South Africa
| | - Leshia Upfold
- Oceans and Coasts Branch Department of Environmental Affairs Cape Town South Africa
| | - Richard B. Sherley
- Environment and Sustainability Institute University of Exeter Exeter UK
- Bristol Zoological Society Bristol UK
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36
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Smith A, Hofner B, Lamb JS, Osenkowski J, Allison T, Sadoti G, McWilliams SR, Paton P. Modeling spatiotemporal abundance of mobile wildlife in highly variable environments using boosted GAMLSS hurdle models. Ecol Evol 2019; 9:2346-2364. [PMID: 30891185 PMCID: PMC6405508 DOI: 10.1002/ece3.4738] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 10/11/2018] [Accepted: 10/30/2018] [Indexed: 11/07/2022] Open
Abstract
Modeling organism distributions from survey data involves numerous statistical challenges, including accounting for zero-inflation, overdispersion, and selection and incorporation of environmental covariates. In environments with high spatial and temporal variability, addressing these challenges often requires numerous assumptions regarding organism distributions and their relationships to biophysical features. These assumptions may limit the resolution or accuracy of predictions resulting from survey-based distribution models. We propose an iterative modeling approach that incorporates a negative binomial hurdle, followed by modeling of the relationship of organism distribution and abundance to environmental covariates using generalized additive models (GAM) and generalized additive models for location, scale, and shape (GAMLSS). Our approach accounts for key features of survey data by separating binary (presence-absence) from count (abundance) data, separately modeling the mean and dispersion of count data, and incorporating selection of appropriate covariates and response functions from a suite of potential covariates while avoiding overfitting. We apply our modeling approach to surveys of sea duck abundance and distribution in Nantucket Sound (Massachusetts, USA), which has been proposed as a location for offshore wind energy development. Our model results highlight the importance of spatiotemporal variation in this system, as well as identifying key habitat features including distance to shore, sediment grain size, and seafloor topographic variation. Our work provides a powerful, flexible, and highly repeatable modeling framework with minimal assumptions that can be broadly applied to the modeling of survey data with high spatiotemporal variability. Applying GAMLSS models to the count portion of survey data allows us to incorporate potential overdispersion, which can dramatically affect model results in highly dynamic systems. Our approach is particularly relevant to systems in which little a priori knowledge is available regarding relationships between organism distributions and biophysical features, since it incorporates simultaneous selection of covariates and their functional relationships with organism responses.
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Affiliation(s)
- Adam Smith
- Department of Natural Resources ScienceUniversity of Rhode IslandKingstonRhode Island
- Present address:
United States Fish and Wildlife Service, National Wildlife Refuge SystemInventory and Monitoring BranchAthensGeorgia
| | - Benjamin Hofner
- Department of Medical Informatics, Biometry and EpidemiologyFriedrich‐Alexander‐University Erlangen‐NurembergErlangenGermany
- Present address:
Section BiostatisticsPaul‐Ehrlich‐InstitutLangenGermany
| | - Juliet S. Lamb
- Department of Natural Resources ScienceUniversity of Rhode IslandKingstonRhode Island
| | - Jason Osenkowski
- Rhode Island Department of Environmental ManagementWest KingstonRhode Island
| | - Taber Allison
- American Wind Wildlife InstituteWashingtonDistrict of Columbia
| | | | - Scott R. McWilliams
- Department of Natural Resources ScienceUniversity of Rhode IslandKingstonRhode Island
| | - Peter Paton
- Department of Natural Resources ScienceUniversity of Rhode IslandKingstonRhode Island
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Heerah K, Cox SL, Blevin P, Guinet C, Charrassin JB. Validation of Dive Foraging Indices Using Archived and Transmitted Acceleration Data: The Case of the Weddell Seal. Front Ecol Evol 2019. [DOI: 10.3389/fevo.2019.00030] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
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38
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Southall BL, Benoit‐Bird KJ, Moline MA, Moretti D. Quantifying deep‐sea predator–prey dynamics: Implications of biological heterogeneity for beaked whale conservation. J Appl Ecol 2019. [DOI: 10.1111/1365-2664.13334] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Brandon L. Southall
- Southall Environmental Associates, Inc. Aptos California
- Long Marine LaboratoryUniversity of California, Santa Cruz Santa Cruz California
| | - Kelly J. Benoit‐Bird
- College of Earth, Ocean, and Atmospheric SciencesOregon State University Corvallis Oregon
- Monterey Bay Aquarium Research Institute Moss Landing California
| | - Mark A. Moline
- College of Earth, Ocean, and EnvironmentUniversity of Delaware Lewes Delaware
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Basedow SL, McKee D, Lefering I, Gislason A, Daase M, Trudnowska E, Egeland ES, Choquet M, Falk-Petersen S. Remote sensing of zooplankton swarms. Sci Rep 2019; 9:686. [PMID: 30679810 PMCID: PMC6346024 DOI: 10.1038/s41598-018-37129-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2018] [Accepted: 12/04/2018] [Indexed: 11/15/2022] Open
Abstract
Zooplankton provide the key link between primary production and higher levels of the marine food web and they play an important role in mediating carbon sequestration in the ocean. All commercially harvested fish species depend on zooplankton populations. However, spatio-temporal distributions of zooplankton are notoriously difficult to quantify from ships. We know that zooplankton can form large aggregations that visibly change the color of the sea, but the scale and mechanisms producing these features are poorly known. Here we show that large surface patches (>1000 km2) of the red colored copepod Calanus finmarchicus can be identified from satellite observations of ocean color. Such observations provide the most comprehensive view of the distribution of a zooplankton species to date, and alter our understanding of the behavior of this key zooplankton species. Moreover, our findings suggest that high concentrations of astaxanthin-rich zooplankton can degrade the performance of standard blue-green reflectance ratio algorithms in operational use for retrieving chlorophyll concentrations from ocean color remote sensing.
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Affiliation(s)
- Sünnje L Basedow
- Department of Arctic and Marine Biology, UiT The Arctic University of Norway, Tromsø, Norway.
| | - David McKee
- Physics Department, University of Strathclyde, Glasgow, United Kingdom
| | - Ina Lefering
- Physics Department, University of Strathclyde, Glasgow, United Kingdom
| | | | - Malin Daase
- Department of Arctic and Marine Biology, UiT The Arctic University of Norway, Tromsø, Norway
| | - Emilia Trudnowska
- Marine Ecology Department, Institute of Oceanology, Polish Academy of Sciences, Sopot, Poland
| | | | - Marvin Choquet
- Faculty of Biosciences and Aquaculture, Nord University, Bodø, Norway
| | - Stig Falk-Petersen
- Department of Arctic and Marine Biology, UiT The Arctic University of Norway, Tromsø, Norway.,Akvaplan-niva AS, Tromsø, Norway
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40
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The role of submesoscale currents in structuring marine ecosystems. Nat Commun 2018; 9:4758. [PMID: 30420651 PMCID: PMC6232172 DOI: 10.1038/s41467-018-07059-3] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 10/10/2018] [Indexed: 11/16/2022] Open
Abstract
From microbes to large predators, there is increasing evidence that marine life is shaped by short-lived submesoscales currents that are difficult to observe, model, and explain theoretically. Whether and how these intense three-dimensional currents structure the productivity and diversity of marine ecosystems is a subject of active debate. Our synthesis of observations and models suggests that the shallow penetration of submesoscale vertical currents might limit their impact on productivity, though ecological interactions at the submesoscale may be important in structuring oceanic biodiversity. Short-lived three-dimensional submesoscale currents, responsible for swirling ocean color chlorophyll filaments, have long been thought to affect productivity. Current research suggests they may not be effective in enhancing phytoplankton growth, but may have important contributions to biodiversity.
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41
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Björnsson B, Karlsson H, Macrander A. Food searching behaviour in adult Atlantic cod Gadus morhua during acoustic training: social learning and leadership within a school. JOURNAL OF FISH BIOLOGY 2018; 93:814-829. [PMID: 30141190 DOI: 10.1111/jfb.13783] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 08/15/2018] [Indexed: 06/08/2023]
Abstract
Food searching behaviour in a group of individually tagged 1-5 kg Atlantic cod Gadus morhua was studied in a set of three experiments in a sea cage with two underwater platforms, where restricted amounts of food was delivered several times per day during an acoustic training period. It took c. 1 week to train 20 naïve cod to associate low frequency (250 Hz) sound with food, whereas the training time was reduced to less than 2 days when 19 naïve G. morhua were accompanied with one trained fish. The fish formed a school that cruised between the platforms in search of food. Usually, there was one leader in the school, a fish that swam faster, arrived first at the platforms and visited the platforms more frequently than other members of the school. The leader spent more energy on swimming but also received more food and grew faster than the rest of the fish. At the start of the experiments, the leaders were not larger than the average fish but always among the leanest ones in the group. The study reveals how social learning can facilitate the acoustic training in adult G. morhua, information that may be useful in finding ways to aggregate valuable fish species for environmentally friendly fishing and ranching.
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Affiliation(s)
- Björn Björnsson
- Marine and Freshwater Research Institute, Aquaculture Division, Reykjavík, Iceland
| | - Hjalti Karlsson
- Marine and Freshwater Research Institute, Aquaculture Division, Reykjavík, Iceland
| | - Andreas Macrander
- Marine and Freshwater Research Institute, Aquaculture Division, Reykjavík, Iceland
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42
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Keen EM, Wray J, Pilkington JF, Thompson KL, Picard CR. Distinct habitat use strategies of sympatric rorqual whales within a fjord system. MARINE ENVIRONMENTAL RESEARCH 2018; 140:180-189. [PMID: 29937199 DOI: 10.1016/j.marenvres.2018.06.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2018] [Revised: 05/31/2018] [Accepted: 06/14/2018] [Indexed: 06/08/2023]
Abstract
We used ecosystem sampling during systematic surveys and opportunistic focal follows, comparison tests, and random forest models to evaluate fin whale (Balaenoptera physalus) and humpback whale (Megaptera novaeangliae) habitat associations within an inland feeding ground (Kitimat Fjord System, British Columbia, Canada). Though these species are sympatric and share a common prey source, they were attuned to different aspects of the local habitat. The fin whales were associated with habitat properties reminiscent of the open ocean. Humpback whales, in contrast, were associated with features more commonly associated with the inland waters of fjords. Fixed habitat features, such as seafloor depth and distance from the fjord mouth, were the most important predictors of fin whale presence, but fixed and dynamic variables, such as surface properties, predicted humpback whale presence with equal (moderate) success. With the exception of strong salinity gradients for humpback whales, habitat conditions were poor predictors of feeding state. Fin whales practiced a spatially confined, seasonally stable, and thus more predictable use of certain channels within the fjord system. These findings are compatible with site loyal behavior, which is interesting in light of the species' historical, unique use of this fjord system. The relatively lackluster performance of humpback-habitat models, coupled with the importance of oceanographic properties, makes the humpback's habitat use strategy more uncertain. The fact that two sympatric species sharing a common prey source exhibited different habitat use strategies suggests that at least one species was informed by something in addition to prey. Given that the two species are attuned to different aspects of the fjord habitat, their responses to habitat changes, including anthropogenic impacts, would likely be different in both nature and degree. Our findings highlight the value of comparative studies and the complexity of rorqual habitat use, which must be understood in order for critical habitat to be identified and protected.
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Affiliation(s)
- E M Keen
- Scripps Institution of Oceanography, La Jolla, CA, USA; North Coast Cetacean Society, Hartley Bay, British Columbia, Canada.
| | - J Wray
- North Coast Cetacean Society, Hartley Bay, British Columbia, Canada.
| | - J F Pilkington
- Cetacean Research Program, Pacific Biological Station, Nanaimo, British Columbia, Canada.
| | - K L Thompson
- Gitga'at Oceans and Lands Department, Hartley Bay, British Columbia, Canada.
| | - C R Picard
- Gitga'at Oceans and Lands Department, Hartley Bay, British Columbia, Canada.
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43
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Carroll G, Harcourt R, Pitcher BJ, Slip D, Jonsen I. Recent prey capture experience and dynamic habitat quality mediate short-term foraging site fidelity in a seabird. Proc Biol Sci 2018; 285:rspb.2018.0788. [PMID: 30051866 DOI: 10.1098/rspb.2018.0788] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 06/28/2018] [Indexed: 11/12/2022] Open
Abstract
Foraging site fidelity allows animals to increase their efficiency by returning to profitable feeding areas. However, the mechanisms underpinning why animals 'stay' or 'switch' sites have rarely been investigated. Here, we explore how habitat quality and prior prey capture experience influence short-term site fidelity by the little penguin (Eudyptula minor). Using 88 consecutive foraging trips by 20 brooding penguins, we found that site fidelity was higher after foraging trips where environmental conditions were favourable, and after trips where prey capture success was high. When penguins exhibited lower site fidelity, the number of prey captures relative to the previous trip increased, suggesting that switches in foraging location were an adaptive strategy in response to low prey capture rates. Penguins foraged closer to where other penguins foraged on the same day than they did to the location of their own previous foraging site, and caught more prey when they foraged close together. This suggests that penguins aggregated flexibly when prey was abundant and accessible. Our results illustrate how foraging predators can integrate information about prior experience with contemporary information such as social cues. This gives insight into how animals combine information adaptively to exploit changing prey distribution in a dynamic environment.
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Affiliation(s)
- Gemma Carroll
- Department of Biological Sciences, Faculty of Science and Engineering, Macquarie University, Herring Rd, North Ryde, New South Wales 2109, Australia .,Institute of Marine Science, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Robert Harcourt
- Department of Biological Sciences, Faculty of Science and Engineering, Macquarie University, Herring Rd, North Ryde, New South Wales 2109, Australia
| | - Benjamin J Pitcher
- Department of Biological Sciences, Faculty of Science and Engineering, Macquarie University, Herring Rd, North Ryde, New South Wales 2109, Australia.,Taronga Conservation Society Australia, Bradley's Head Rd, Mosman, New South Wales 2088, Australia
| | - David Slip
- Taronga Conservation Society Australia, Bradley's Head Rd, Mosman, New South Wales 2088, Australia
| | - Ian Jonsen
- Department of Biological Sciences, Faculty of Science and Engineering, Macquarie University, Herring Rd, North Ryde, New South Wales 2109, Australia
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44
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van Beest FM, Teilmann J, Dietz R, Galatius A, Mikkelsen L, Stalder D, Sveegaard S, Nabe-Nielsen J. Environmental drivers of harbour porpoise fine-scale movements. MARINE BIOLOGY 2018; 165:95. [PMID: 29725140 PMCID: PMC5924767 DOI: 10.1007/s00227-018-3346-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Accepted: 04/04/2018] [Indexed: 06/08/2023]
Abstract
Quantifying intraspecific variation in movement behaviour of marine predators and the underlying environmental drivers is important to inform conservation management of protected species. Here, we provide the first empirical data on fine-scale movements of free-ranging harbour porpoises (Phocoena phocoena) in their natural habitat. Data were obtained from six individuals, tagged in two areas of the Danish North Sea, that were equipped with Global Positioning System (GPS) and dive recorder units (V-tags). We used multi-model inference and model averaging to evaluate the relative importance of various static and dynamic environmental conditions on the movement characteristics: speed, turning angle, dive duration, dive depth, dive wiggliness (a proxy for prey chasing behaviour), and post-dive duration. Despite substantial individual differences in horizontal and vertical movement patterns, we found that all the tracked porpoises responded similar to variation in environmental conditions and displayed movements that indicate a higher likelihood of foraging behaviour in shallower and more saline waters. Our study contributes to the identification of important feeding areas for porpoises and can be used to improve existing movement-based simulation models that aim to assess the impact of anthropogenic disturbance on harbour porpoise populations.
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Affiliation(s)
- Floris M. van Beest
- Department of Bioscience, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark
| | - Jonas Teilmann
- Department of Bioscience, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark
| | - Rune Dietz
- Department of Bioscience, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark
| | - Anders Galatius
- Department of Bioscience, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark
| | - Lonnie Mikkelsen
- Department of Bioscience, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark
| | - Dominique Stalder
- Department of Bioscience, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark
| | - Signe Sveegaard
- Department of Bioscience, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark
| | - Jacob Nabe-Nielsen
- Department of Bioscience, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark
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45
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Gagne TO, Hyrenbach KD, Hagemann ME, Van Houtan KS. Trophic signatures of seabirds suggest shifts in oceanic ecosystems. SCIENCE ADVANCES 2018; 4:eaao3946. [PMID: 29457134 PMCID: PMC5812733 DOI: 10.1126/sciadv.aao3946] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 01/12/2018] [Indexed: 06/08/2023]
Abstract
Pelagic ecosystems are dynamic ocean regions whose immense natural capital is affected by climate change, pollution, and commercial fisheries. Trophic level-based indicators derived from fishery catch data may reveal the food web status of these systems, but the utility of these metrics has been debated because of targeting bias in fisheries catch. We analyze a unique, fishery-independent data set of North Pacific seabird tissues to inform ecosystem trends over 13 decades (1890s to 2010s). Trophic position declined broadly in five of eight species sampled, indicating a long-term shift from higher-trophic level to lower-trophic level prey. No species increased their trophic position. Given species prey preferences, Bayesian diet reconstructions suggest a shift from fishes to squids, a result consistent with both catch reports and ecosystem models. Machine learning models further reveal that trophic position trends have a complex set of drivers including climate, commercial fisheries, and ecomorphology. Our results show that multiple species of fish-consuming seabirds may track the complex changes occurring in marine ecosystems.
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Affiliation(s)
- Tyler O. Gagne
- Monterey Bay Aquarium, 886 Cannery Row, Monterey, CA 93940, USA
| | - K. David Hyrenbach
- Hawaii Pacific University, 45-045 Kamehameha Highway, Kaneohe, HI 96744, USA
| | - Molly E. Hagemann
- Vertebrate Zoology Collections, Bernice Pauahi Bishop Museum, 1525 Bernice Street, Honolulu, HI 96817, USA
| | - Kyle S. Van Houtan
- Monterey Bay Aquarium, 886 Cannery Row, Monterey, CA 93940, USA
- Nicholas School of the Environment, Duke University, Box 90328, Durham, NC 27708, USA
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46
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Respiratory behaviors in sympatric rorqual whales: the influence of prey depth and implications for temporal access to prey. J Mammal 2017. [DOI: 10.1093/jmammal/gyx170] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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47
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Scales KL, Hazen EL, Maxwell SM, Dewar H, Kohin S, Jacox MG, Edwards CA, Briscoe DK, Crowder LB, Lewison RL, Bograd SJ. Fit to predict? Eco-informatics for predicting the catchability of a pelagic fish in near real time. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2017; 27:2313-2329. [PMID: 28833890 DOI: 10.1002/eap.1610] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 05/24/2017] [Accepted: 07/11/2017] [Indexed: 06/07/2023]
Abstract
The ocean is a dynamic environment inhabited by a diverse array of highly migratory species, many of which are under direct exploitation in targeted fisheries. The timescales of variability in the marine realm coupled with the extreme mobility of ocean-wandering species such as tuna and billfish complicates fisheries management. Developing eco-informatics solutions that allow for near real-time prediction of the distributions of highly mobile marine species is an important step towards the maturation of dynamic ocean management and ecological forecasting. Using 25 yr (1990-2014) of NOAA fisheries' observer data from the California drift gillnet fishery, we model relative probability of occurrence (presence-absence) and catchability (total catch per gillnet set) of broadbill swordfish Xiphias gladius in the California Current System. Using freely available environmental data sets and open source software, we explore the physical drivers of regional swordfish distribution. Comparing models built upon remotely sensed data sets with those built upon a data-assimilative configuration of the Regional Ocean Modelling System (ROMS), we explore trade-offs in model construction, and address how physical data can affect predictive performance and operational capacity. Swordfish catchability was found to be highest in deeper waters (>1,500 m) with surface temperatures in the 14-20°C range, isothermal layer depth (ILD) of 20-40 m, positive sea surface height (SSH) anomalies, and during the new moon (<20% lunar illumination). We observed a greater influence of mesoscale variability (SSH, wind speed, isothermal layer depth, eddy kinetic energy) in driving swordfish catchability (total catch) than was evident in predicting the relative probability of presence (presence-absence), confirming the utility of generating spatiotemporally dynamic predictions. Data-assimilative ROMS circumvent the limitations of satellite remote sensing in providing physical data fields for species distribution models (e.g., cloud cover, variable resolution, subsurface data), and facilitate broad-scale prediction of dynamic species distributions in near real time.
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Affiliation(s)
- Kylie L Scales
- Institute of Marine Science, University of California Santa Cruz, Santa Cruz, California, 95064, USA
- Environmental Research Division, NOAA Southwest Fisheries Science Center, 99 Pacific Street, Suite #255A, Monterey, California, 93940, USA
- University of the Sunshine Coast, Maroochydore, Queensland, 4556, Australia
| | - Elliott L Hazen
- Institute of Marine Science, University of California Santa Cruz, Santa Cruz, California, 95064, USA
- Environmental Research Division, NOAA Southwest Fisheries Science Center, 99 Pacific Street, Suite #255A, Monterey, California, 93940, USA
| | - Sara M Maxwell
- Old Dominion University, 5115 Hampton Boulevard, Norfolk, Virginia, 23529, USA
| | - Heidi Dewar
- NOAA Southwest Fisheries Science Center, 8901 La Jolla Shores Drive, La Jolla, California, 92037, USA
| | - Suzanne Kohin
- NOAA Southwest Fisheries Science Center, 8901 La Jolla Shores Drive, La Jolla, California, 92037, USA
| | - Michael G Jacox
- Institute of Marine Science, University of California Santa Cruz, Santa Cruz, California, 95064, USA
- Environmental Research Division, NOAA Southwest Fisheries Science Center, 99 Pacific Street, Suite #255A, Monterey, California, 93940, USA
| | - Christopher A Edwards
- Institute of Marine Science, University of California Santa Cruz, Santa Cruz, California, 95064, USA
| | - Dana K Briscoe
- Hopkins Marine Station of Stanford University, 120 Ocean View Boulevard, Pacific Grove, California, 93950, USA
| | - Larry B Crowder
- Hopkins Marine Station of Stanford University, 120 Ocean View Boulevard, Pacific Grove, California, 93950, USA
| | - Rebecca L Lewison
- San Diego State University, 5500 Campanile Drive, San Diego, California, 92182, USA
| | - Steven J Bograd
- Environmental Research Division, NOAA Southwest Fisheries Science Center, 99 Pacific Street, Suite #255A, Monterey, California, 93940, USA
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48
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Chimienti M, Cornulier T, Owen E, Bolton M, Davies IM, Travis JMJ, Scott BE. Taking movement data to new depths: Inferring prey availability and patch profitability from seabird foraging behavior. Ecol Evol 2017; 7:10252-10265. [PMID: 29238552 PMCID: PMC5723613 DOI: 10.1002/ece3.3551] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 09/21/2017] [Accepted: 09/22/2017] [Indexed: 11/17/2022] Open
Abstract
Detailed information acquired using tracking technology has the potential to provide accurate pictures of the types of movements and behaviors performed by animals. To date, such data have not been widely exploited to provide inferred information about the foraging habitat. We collected data using multiple sensors (GPS, time depth recorders, and accelerometers) from two species of diving seabirds, razorbills (Alca torda, N = 5, from Fair Isle, UK) and common guillemots (Uria aalge, N = 2 from Fair Isle and N = 2 from Colonsay, UK). We used a clustering algorithm to identify pursuit and catching events and the time spent pursuing and catching underwater, which we then used as indicators for inferring prey encounters throughout the water column and responses to changes in prey availability of the areas visited at two levels: individual dives and groups of dives. For each individual dive (N = 661 for guillemots, 6214 for razorbills), we modeled the number of pursuit and catching events, in relation to dive depth, duration, and type of dive performed (benthic vs. pelagic). For groups of dives (N = 58 for guillemots, 156 for razorbills), we modeled the total time spent pursuing and catching in relation to time spent underwater. Razorbills performed only pelagic dives, most likely exploiting prey available at shallow depths as indicated by the vertical distribution of pursuit and catching events. In contrast, guillemots were more flexible in their behavior, switching between benthic and pelagic dives. Capture attempt rates indicated that they were exploiting deep prey aggregations. The study highlights how novel analysis of movement data can give new insights into how animals exploit food patches, offering a unique opportunity to comprehend the behavioral ecology behind different movement patterns and understand how animals might respond to changes in prey distributions.
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Affiliation(s)
- Marianna Chimienti
- School of Biological Sciences University of Aberdeen Aberdeen UK.,Marine Scotland Science Marine Laboratory Scottish Government Aberdeen UK
| | - Thomas Cornulier
- School of Biological Sciences University of Aberdeen Aberdeen UK
| | - Ellie Owen
- RSPB Centre for Conservation Science North Scotland Office Inverness UK
| | - Mark Bolton
- RSPB Centre for Conservation Science The Lodge Sandy Bedfordshire UK
| | - Ian M Davies
- Marine Scotland Science Marine Laboratory Scottish Government Aberdeen UK
| | | | - Beth E Scott
- School of Biological Sciences University of Aberdeen Aberdeen UK
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49
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Seabird distribution patterns observed with fishing vessel's radar reveal previously undescribed sub-meso-scale clusters. Sci Rep 2017; 7:7364. [PMID: 28779100 PMCID: PMC5544669 DOI: 10.1038/s41598-017-07480-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Accepted: 06/29/2017] [Indexed: 11/16/2022] Open
Abstract
Seabirds are known to concentrate on prey patches or at predators aggregations standing for potential feeding opportunities. They may search for prey using olfaction or by detecting visually feeding con-specifics and sub-surface predators, or even boats. Thus, they might form a foraging network. We hypothesized that conditionally to the existence of a foraging network, the visual detection ability of seabirds should have a bearing on their medium-scale distribution at sea. Using a fishing-boat radar to catch the instantaneous distribution of seabirds groups within 30 km around the vessel, we conducted a spatial clustering of the seabird-echoes. We found 7,657 clusters (i.e. aggregations of echoes), lasting less than 15 minutes and measuring 9.2 km in maximum length (median). Distances between seabirds groups within clusters showed little variation (median: 2.1 km; CV: 0.5), while area varied largely (median: 21.9 km2; CV: 0.8). Given existing data on seabirds’ reaction distances to boats or other marine predators, we suggest that these structures may represent active foraging sequences of seabirds spreading themselves in space such as to possibly cue on each others. These seabird clusters were not previously described and are size compatible with the existence of a foraging network.
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Tickler DM, Letessier TB, Koldewey HJ, Meeuwig JJ. Drivers of abundance and spatial distribution of reef-associated sharks in an isolated atoll reef system. PLoS One 2017; 12:e0177374. [PMID: 28562602 PMCID: PMC5451018 DOI: 10.1371/journal.pone.0177374] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Accepted: 04/26/2017] [Indexed: 11/18/2022] Open
Abstract
We investigated drivers of reef shark demography across a large and isolated marine protected area, the British Indian Ocean Territory Marine Reserve, using stereo baited remote underwater video systems. We modelled shark abundance against biotic and abiotic variables at 35 sites across the reserve and found that the biomass of low trophic order fish (specifically planktivores) had the greatest effect on shark abundance, although models also included habitat variables (depth, coral cover and site type). There was significant variation in the composition of the shark assemblage at different atolls within the reserve. In particular, the deepest habitat sampled (a seamount at 70-80m visited for the first time in this study) recorded large numbers of scalloped hammerhead sharks (Sphyrna lewini) not observed elsewhere. Size structure of the most abundant and common species, grey reef sharks (Carcharhinus amblyrhynchos), varied with location. Individuals at an isolated bank were 30% smaller than those at the main atolls, with size structure significantly biased towards the size range for young of year (YOY). The 18 individuals judged to be YOY represented the offspring of between four and six females, so, whilst inconclusive, these data suggest the possible use of a common pupping site by grey reef sharks. The importance of low trophic order fish biomass (i.e. potential prey) in predicting spatial variation in shark abundance is consistent with other studies both in marine and terrestrial systems which suggest that prey availability may be a more important predictor of predator distribution than habitat suitability. This result supports the need for ecosystem level rather than species-specific conservation measures to support shark recovery. The observed spatial partitioning amongst sites for species and life-stages also implies the need to include a diversity of habitats and reef types within a protected area for adequate protection of reef-associated shark assemblages.
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Affiliation(s)
- David M. Tickler
- Oceans Institute: Centre for Marine Futures, University of Western Australia, 35 Stirling Highway, Crawley, Perth, WA, Australia
- * E-mail:
| | - Tom B. Letessier
- Oceans Institute: Centre for Marine Futures, University of Western Australia, 35 Stirling Highway, Crawley, Perth, WA, Australia
- Zoological Society of London, Regents Park, London, United Kingdom
| | - Heather J. Koldewey
- Zoological Society of London, Regents Park, London, United Kingdom
- Centre for Ecology & Conservation, University of Exeter, Cornwall Campus, United Kingdom
| | - Jessica J. Meeuwig
- Oceans Institute: Centre for Marine Futures, University of Western Australia, 35 Stirling Highway, Crawley, Perth, WA, Australia
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