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Fontes J, Schouten M, Afonso P, Macena B. The return of Scarface: Philopatry in an ocean wandering shark? Ecology 2024; 105:e4234. [PMID: 38228407 DOI: 10.1002/ecy.4234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 10/18/2023] [Accepted: 11/10/2023] [Indexed: 01/18/2024]
Affiliation(s)
- Jorge Fontes
- Institute of Marine Sciences - Okeanos, University of the Azores, Horta, Portugal
| | | | - Pedro Afonso
- Institute of Marine Sciences - Okeanos, University of the Azores, Horta, Portugal
| | - Bruno Macena
- Institute of Marine Sciences - Okeanos, University of the Azores, Horta, Portugal
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2
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Humphries NE, Fuller DW, Schaefer KM, Sims DW. Highly active fish in low oxygen environments: vertical movements and behavioural responses of bigeye and yellowfin tunas to oxygen minimum zones in the eastern Pacific Ocean. MARINE BIOLOGY 2024; 171:55. [PMID: 38226137 PMCID: PMC10787700 DOI: 10.1007/s00227-023-04366-2] [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: 01/24/2023] [Accepted: 11/24/2023] [Indexed: 01/17/2024]
Abstract
Oxygen minimum zones in the open ocean are predicted to significantly increase in volume over the coming decades as a result of anthropogenic climatic warming. The resulting reduction in dissolved oxygen (DO) in the pelagic realm is likely to have detrimental impacts on water-breathing organisms, particularly those with higher metabolic rates, such as billfish, tunas, and sharks. However, little is known about how free-living fish respond to low DO environments, and therefore, the effect increasing OMZs will have cannot be predicted reliably. Here, we compare the responses of two active predators (bigeye tuna Thunnus obesus and yellowfin tuna Thunnus albacares) to DO at depth throughout the eastern Pacific Ocean. Using time-series data from 267 tagged tunas (59,910 days) and 3D maps of modelled DO, we find that yellowfin tuna respond to low DO at depth by spending more time in shallower, more oxygenated waters. By contrast, bigeye tuna, which forage at deeper depths well below the thermocline, show fewer changes in their use of the water column. However, we find that bigeye tuna increased the frequency of brief upward vertical excursions they performed by four times when DO at depth was lower, but with no concomitant significant difference in temperature, suggesting that this behaviour is driven in part by the need to re-oxygenate following time spent in hypoxic waters. These findings suggest that increasing OMZs will impact the behaviour of these commercially important species, and it is therefore likely that other water-breathing predators with higher metabolic rates will face similar pressures. A more comprehensive understanding of the effect of shoaling OMZs on pelagic fish vertical habitat use, which may increase their vulnerability to surface fisheries, will be important to obtain if these effects are to be mitigated by future management actions. Supplementary Information The online version contains supplementary material available at 10.1007/s00227-023-04366-2.
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Affiliation(s)
- Nicolas E. Humphries
- The Laboratory, Marine Biological Association, Citadel Hill, Plymouth, PL1 2PB UK
| | - Daniel W. Fuller
- Inter-American Tropical Tuna Commission, La Jolla, San Diego, CA USA
| | - Kurt M. Schaefer
- Inter-American Tropical Tuna Commission, La Jolla, San Diego, CA USA
| | - David W. Sims
- The Laboratory, Marine Biological Association, Citadel Hill, Plymouth, PL1 2PB UK
- Ocean and Earth Science, University of Southampton, National Oceanography Centre Southampton, Waterfront Campus, Southampton, SO14 3ZH UK
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3
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Correia S, Fernández-Boo S, Magalhães L, de Montaudouin X, Daffe G, Poulin R, Vera M. Trematode genetic patterns at host individual and population scales provide insights about infection mechanisms. Parasitology 2023; 150:1207-1220. [PMID: 38084628 PMCID: PMC10941227 DOI: 10.1017/s0031182023000987] [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: 05/22/2023] [Revised: 10/02/2023] [Accepted: 10/07/2023] [Indexed: 01/10/2024]
Abstract
Multiple parasites can infect a single host, creating a dynamic environment where each parasite must compete over host resources. Such interactions can cause greater harm to the host than single infections and can also have negative consequences for the parasites themselves. In their first intermediate hosts, trematodes multiply asexually and can eventually reach up to 20% of the host's biomass. In most species, it is unclear whether this biomass results from a single infection or co-infection by 2 or more infective stages (miracidia), the latter being more likely a priori in areas where prevalence of infection is high. Using as model system the trematode Bucephalus minimus and its first intermediate host cockles, we examined the genetic diversity of the cytochrome c oxidase subunit I region in B. minimus from 3 distinct geographical areas and performed a phylogeographic study of B. minimus populations along the Northeast Atlantic coast. Within localities, the high genetic variability found across trematodes infecting different individual cockles, compared to the absence of variability within the same host, suggests that infections could be generally originating from a single miracidium. On a large spatial scale, we uncovered significant population structure of B. minimus, specifically between the north and south of Bay of Biscay. Although other explanations are possible, we suggest this pattern may be driven by the population structure of the final host.
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Affiliation(s)
- Simão Correia
- Department of Biology, CESAM, University of Aveiro, 3810-193 Aveiro, Portugal
- Aquatic and Animal Health Group, CIIMAR, University of Porto, 4450-208 Matosinhos, Portugal
- Department of Zoology, Genetics and Physical Anthropology, Campus Terra, University of Santiago de Compostela, 27002 Lugo, Spain
- Department of Zoology, University of Otago, 9054 Dunedin, New Zealand
| | - Sergio Fernández-Boo
- Aquatic and Animal Health Group, CIIMAR, University of Porto, 4450-208 Matosinhos, Portugal
| | - Luísa Magalhães
- Department of Biology, CESAM, University of Aveiro, 3810-193 Aveiro, Portugal
| | | | - Guillemine Daffe
- Université de Bordeaux, CNRS, Observatoire Aquitain des Sciences de l'Univers, F-33615 Pessac, France
| | - Robert Poulin
- Department of Zoology, University of Otago, 9054 Dunedin, New Zealand
| | - Manuel Vera
- Department of Zoology, Genetics and Physical Anthropology, Campus Terra, University of Santiago de Compostela, 27002 Lugo, Spain
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4
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Nikolic N, Devloo-Delva F, Bailleul D, Noskova E, Rougeux C, Delord C, Borsa P, Liautard-Haag C, Hassan M, Marie AD, Feutry P, Grewe P, Davies C, Farley J, Fernando D, Biton-Porsmoguer S, Poisson F, Parker D, Leone A, Aulich J, Lansdell M, Marsac F, Arnaud-Haond S. Stepping up to genome scan allows stock differentiation in the worldwide distributed blue shark Prionace glauca. Mol Ecol 2023; 32:1000-1019. [PMID: 36511846 DOI: 10.1111/mec.16822] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 11/29/2022] [Accepted: 12/01/2022] [Indexed: 12/15/2022]
Abstract
The blue shark Prionace glauca is a top predator with one of the widest geographical distributions of any shark species. It is classified as Critically Endangered in the Mediterranean Sea, and Near Threatened globally. Previous genetic studies did not reject the null hypothesis of a single global population. The blue shark was proposed as a possible archetype of the "grey zone of population differentiation," coined to designate cases where population structure may be too recent or too faint to be detected using a limited set of markers. Here, blue shark samples collected throughout its global range were sequenced using a specific RAD method (DArTseq), which recovered 37,655 genome-wide single nucleotide polymorphisms (SNPs). Two main groups emerged, with Mediterranean Sea and northern Atlantic samples (Northern population) differentiated significantly from the Indo-west Pacific samples (Southern population). Significant pairwise FST values indicated further genetic differentiation within the Atlantic Ocean, and between the Atlantic Ocean and the Mediterranean Sea. Reconstruction of recent demographic history suggested divergence between Northern and Southern populations occurred about 500 generations ago and revealed a drastic reduction in effective population size from a large ancestral population. Our results illustrate the power of genome scans to detect population structure and reconstruct demographic history in highly migratory marine species. Given that the management plans of the blue shark (targeted or bycatch) fisheries currently assume panmictic regional stocks, we strongly recommend that the results presented here be considered in future stock assessments and conservation strategies.
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Affiliation(s)
- Natacha Nikolic
- UMR MARBEC, University of Montpellier, IRD, Ifremer, CNRS, Sète, France.,INRAE, Ecobiop, AQUA, Saint-Pée-sur-Nivelle, France.,ARBRE, Agence de Recherche pour la Biodiversité à la Réunion, Saint-Gilles, France
| | - Floriaan Devloo-Delva
- CSIRO Environment, Hobart, Tasmania, Australia.,School of Natural Sciences-Quantitative Marine Science, University of Tasmania, Hobart, Tasmania, Australia
| | - Diane Bailleul
- UMR MARBEC, University of Montpellier, IRD, Ifremer, CNRS, Sète, France
| | - Ekaterina Noskova
- Computer Technologies Laboratory, ITMO University, St Petersburg, Russia
| | | | - Chrystelle Delord
- UMR MARBEC, University of Montpellier, IRD, Ifremer, CNRS, Sète, France
| | - Philippe Borsa
- Institut de recherche pour le développement, UMR ENTROPIE, Montpellier, France
| | | | - Mohamad Hassan
- UMR MARBEC, University of Montpellier, IRD, Ifremer, CNRS, Sète, France.,Animal Production Department, Tishreen University, Latakia, Syria
| | - Amandine D Marie
- ARBRE, Agence de Recherche pour la Biodiversité à la Réunion, Saint-Gilles, France
| | | | - Peter Grewe
- CSIRO Environment, Hobart, Tasmania, Australia
| | | | | | | | | | - François Poisson
- UMR MARBEC, University of Montpellier, IRD, Ifremer, CNRS, Sète, France
| | - Denham Parker
- Department of Forestry, Fisheries and the Environment, (DFFE), Cape Town, South Africa.,Department of Biological Sciences, University of Cape Town, Rondebosch, South Africa
| | - Agostino Leone
- UMR MARBEC, University of Montpellier, IRD, Ifremer, CNRS, Sète, France
| | | | | | - Francis Marsac
- UMR MARBEC, University of Montpellier, IRD, Ifremer, CNRS, Sète, France
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5
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Rondon-Medicci M, Cardoso LG, Mourato B, Dalla Rosa L. Blue shark (Prionace glauca) occurrence and relative abundance in the western South Atlantic Ocean influenced by spatiotemporal variability, environmental variables, and oceanographic processes. MARINE ENVIRONMENTAL RESEARCH 2023; 183:105842. [PMID: 36481717 DOI: 10.1016/j.marenvres.2022.105842] [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: 07/31/2022] [Revised: 11/26/2022] [Accepted: 11/29/2022] [Indexed: 06/17/2023]
Abstract
The aim of this study was to evaluate spatiotemporal patterns in the distribution and relative abundance of blue sharks and their relationship with environmental variables and oceanographic processes in the southwestern Atlantic Ocean. We modeled data on catch records from the Brazilian pelagic tuna longline fleet using generalized additive models (GAMs). The distribution of Prionace glauca was influenced by salinity, chlorophyll-a and temperature. Our models showed that both the catch per unit of fishing effort (CPUE) and the probability of presence increased mainly between March and August. The CPUE was also influenced by ocean depth and sea surface height, and the probability of occurrence by ocean fronts and slope. The highest CPUE values and probability of occurrence of blue sharks tended to occur mainly in parts of the continental slope off Brazil and at the Rio Grande Rise, characterized by the presence of seamounts. Such hotspots for P. glauca could potentially be considered in fisheries management plans.
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Affiliation(s)
- Maria Rondon-Medicci
- Laboratório de Ecologia e Conservação de Megafauna Marinha, Universidade Federal do Rio Grande - FURG. Instituto de Oceanografia, Av. Itália km. 8 s/n, Campus Carreiros, CEP 96203-000, Rio Grande, RS, Brazil; Programa de Pós-graduação em Oceanografia Biológica, Universidade Federal do Rio Grande - FURG. Instituto de Oceanografia, Rio Grande, RS, Brazil.
| | - Luis G Cardoso
- Programa de Pós-graduação em Oceanografia Biológica, Universidade Federal do Rio Grande - FURG. Instituto de Oceanografia, Rio Grande, RS, Brazil; Laboratório de Recursos Pesqueiros Demersais e Cefalópodes, Universidade Federal do Rio Grande - FURG. Instituto de Oceanografia, Rio Grande, RS, Brazil
| | - Bruno Mourato
- Instituto do Mar, Universidade Federal de São Paulo - UNIFESP, Santos, SP, Brazil
| | - L Dalla Rosa
- Laboratório de Ecologia e Conservação de Megafauna Marinha, Universidade Federal do Rio Grande - FURG. Instituto de Oceanografia, Av. Itália km. 8 s/n, Campus Carreiros, CEP 96203-000, Rio Grande, RS, Brazil; Programa de Pós-graduação em Oceanografia Biológica, Universidade Federal do Rio Grande - FURG. Instituto de Oceanografia, Rio Grande, RS, Brazil
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6
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Vidal A, Cardador L, Garcia-Barcelona S, Macias D, Druon JN, Coll M, Navarro J. The relative importance of biological and environmental factors on the trophodynamics of a pelagic marine predator, the blue shark (Prionace glauca). MARINE ENVIRONMENTAL RESEARCH 2023; 183:105808. [PMID: 36403409 DOI: 10.1016/j.marenvres.2022.105808] [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: 07/06/2022] [Revised: 11/05/2022] [Accepted: 11/07/2022] [Indexed: 06/16/2023]
Abstract
Marine ecosystems have been significantly altered by the cumulative impacts of human activities. Pelagic sharks have become vulnerable to increases in mortality rates caused by fishing. The decrease in number of these top predators could have substantial cascading effects on wider marine communities. Concerns about these potential impacts, and the critical need for effective management, have led to an increased interest in assessing the trophic ecology of sharks. While stable isotope analyses have been used to provide relevant insights about the trophic ecology of sharks, the causal factors leading to trophic variation between individuals has been largely overlooked. Here, we investigated the relative effect of biological factors, geographic location, and environmental factors on the spatial trophodynamics of the blue shark (Prionace glauca). Specifically, stable isotope values of δ15N and δ13C, and the estimated trophic position (TP) were analysed for 180 blue sharks collected from south of the Canary Islands in the Atlantic Ocean, to the north-western Mediterranean Sea. The results showed that models which included combined variables explained the variation in δ15N, TP and δ13C values better than models which considered only stand-alone predictors. The independent contributions of environmental variables and biological factors seemed to be more important than geographic location for δ15N and TP. δ15N and TP increased in a curvilinear fashion with body size, and TP was higher for females. In the case of δ13C values, only an effect from sex was observed. Among environmental variables, chlorophyll-a, pelagic productivity, and sea-surface temperature proved to be reliable predictors, particularly for δ15N and TP, most likely due to their relationship with productivity and prey availability. This study provides new information on ranking the factors that influence the trophodynamics of the blue shark, namely the environment, the geographic location, and the biological factors of the species.
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Affiliation(s)
- Alba Vidal
- Institut de Ciències Del Mar (ICM), CSIC, Passeig Marítim de la Barceloneta 37, 08003, Barcelona, Spain; Ecological and Forestry Applications Research Centre, Campus de Bellaterra (UAB), Edifici C, 08193, Cerdanyola Del Vallès, Spain
| | - Laura Cardador
- Ecological and Forestry Applications Research Centre, Campus de Bellaterra (UAB), Edifici C, 08193, Cerdanyola Del Vallès, Spain
| | | | - David Macias
- Centro Oceanográfico de Málaga (IEO-CSIC), Puerto Pesquero, s/n, 29640, Fuengirola, Spain
| | - Jean-Noel Druon
- Joint Research Centre (JRC), European Commission, Ispra, Italy
| | - Marta Coll
- Institut de Ciències Del Mar (ICM), CSIC, Passeig Marítim de la Barceloneta 37, 08003, Barcelona, Spain
| | - Joan Navarro
- Institut de Ciències Del Mar (ICM), CSIC, Passeig Marítim de la Barceloneta 37, 08003, Barcelona, Spain.
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7
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Logan JM, Golet W, Smith SC, Neilson J, Van Guelpen L. Broadbill swordfish (Xiphias gladius) foraging and vertical movements in the north-west Atlantic. JOURNAL OF FISH BIOLOGY 2021; 99:557-568. [PMID: 33792926 DOI: 10.1111/jfb.14744] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 03/12/2021] [Accepted: 03/31/2021] [Indexed: 06/12/2023]
Abstract
The northern edge of Georges Bank is an important seasonal foraging habitat for swordfish (Xiphias gladius) in the North Atlantic, where aggregations support commercial pelagic longline and harpoon fisheries. Following a period of overfishing during the 1990s, the North Atlantic X. gladius stock underwent a period of recovery during the early 2000s and was considered rebuilt in 2009. We analysed stomach contents from X. gladius (n = 39) harvested by the Canadian harpoon fishery on Georges Bank in 2007 to characterize diet in this important foraging habitat. We used electronic tagging data from X. gladius (n = 6) on Georges Bank in 2005-2007 to assess vertical habitat preferences and associated prey composition within those zones. We also used stable isotope analysis (δ13 C and δ15 N) of X. gladius liver (n = 2) and common prey types (Paralepididae, Myctophidae, Merluccidae, Ommastrephidae) as a longer-term record of feeding. Stomach contents were co-dominated by Paralepididae [31.9% weight (W)] and Ommastrephidae (36.8%W) with secondary contributions from hake (Merluccidae, 6.5%W), Myctophidae (2.9%W) and Sebastidae (2.1%W). X. gladius displayed diel vertical migrations, descending to depths of 300-400 m during daytime followed by residence in surface waters at night. X. gladius liver δ15 N values were similar to or lower than values of primary stomach contents, likely due to bias of diet consumed in southerly waters with lower nitrogen isotope baselines prior to arrival on Georges Bank. Diet data are similar to results from historical studies from the late 1950s to the early 1980s. This apparent temporal stability to the underlying food web in this region may explain the high X. gladius site fidelity observed in electronic tagging studies and the consistent aggregation of these fish to this region.
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Affiliation(s)
- John M Logan
- Massachusetts Division of Marine Fisheries, New Bedford, Massachusetts, USA
| | - Walt Golet
- The School of Marine Sciences, The University of Maine, Orono, The Gulf of Maine Research Institute, Portland, Maine, USA
| | - Sean C Smith
- Department of Fisheries and Oceans Canada, Bedford Institute of Oceanography, Dartmouth, Nova Scotia, Canada
| | | | - Lou Van Guelpen
- Atlantic Reference Centre, Huntsman Marine Science Centre, St. Andrews, New Brunswick, Canada
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8
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Vedor M, Queiroz N, Mucientes G, Couto A, Costa ID, Santos AD, Vandeperre F, Fontes J, Afonso P, Rosa R, Humphries NE, Sims DW. Climate-driven deoxygenation elevates fishing vulnerability for the ocean's widest ranging shark. eLife 2021; 10:62508. [PMID: 33461659 PMCID: PMC7815312 DOI: 10.7554/elife.62508] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Accepted: 12/17/2020] [Indexed: 12/24/2022] Open
Abstract
Climate-driven expansions of ocean hypoxic zones are predicted to concentrate pelagic fish in oxygenated surface layers, but how expanding hypoxia and fisheries will interact to affect threatened pelagic sharks remains unknown. Here, analysis of satellite-tracked blue sharks and environmental modelling in the eastern tropical Atlantic oxygen minimum zone (OMZ) shows shark maximum dive depths decreased due to combined effects of decreasing dissolved oxygen (DO) at depth, high sea surface temperatures, and increased surface-layer net primary production. Multiple factors associated with climate-driven deoxygenation contributed to blue shark vertical habitat compression, potentially increasing their vulnerability to surface fisheries. Greater intensity of longline fishing effort occurred above the OMZ compared to adjacent waters. Higher shark catches were associated with strong DO gradients, suggesting potential aggregation along suitable DO gradients contributed to habitat compression and higher fishing-induced mortality. Fisheries controls to counteract deoxygenation effects on shark catches will be needed as oceans continue warming.
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Affiliation(s)
- Marisa Vedor
- CIBIO/InBIO, Universidade do Porto, Campus Agrário de Vairão, Vairão, Portugal.,MARE, Laboratório Marítimo da Guia, Faculdade de Ciências da Universidade de Lisboa, Av. Nossa Senhora do Cabo, Cascais, Portugal
| | - Nuno Queiroz
- CIBIO/InBIO, Universidade do Porto, Campus Agrário de Vairão, Vairão, Portugal.,Marine Biological Association of the United Kingdom, The Laboratory, Citadel Hill, Plymouth, United Kingdom
| | - Gonzalo Mucientes
- CIBIO/InBIO, Universidade do Porto, Campus Agrário de Vairão, Vairão, Portugal.,Instituto de Investigaciones Marinas, Consejo Superior de Investigaciones Científicas (IIM-CSIC), Vigo, Spain
| | - Ana Couto
- CIBIO/InBIO, Universidade do Porto, Campus Agrário de Vairão, Vairão, Portugal
| | - Ivo da Costa
- CIBIO/InBIO, Universidade do Porto, Campus Agrário de Vairão, Vairão, Portugal
| | - António Dos Santos
- CIBIO/InBIO, Universidade do Porto, Campus Agrário de Vairão, Vairão, Portugal
| | - Frederic Vandeperre
- IMAR - Institute of Marine Research, Departamento de Oceanografia e Pescas, Universidade dos Açores, Horta, Portugal.,MARE - Marine and Environmental Sciences Centre, Faculdade de Ciências da Universidade de Lisboa, Lisbon, Portugal.,Okeanos - Departamento de Oceanografia e Pescas, Universidade dos Açores, Horta, Portugal
| | - Jorge Fontes
- IMAR - Institute of Marine Research, Departamento de Oceanografia e Pescas, Universidade dos Açores, Horta, Portugal.,Okeanos - Departamento de Oceanografia e Pescas, Universidade dos Açores, Horta, Portugal
| | - Pedro Afonso
- IMAR - Institute of Marine Research, Departamento de Oceanografia e Pescas, Universidade dos Açores, Horta, Portugal.,Okeanos - Departamento de Oceanografia e Pescas, Universidade dos Açores, Horta, Portugal
| | - Rui Rosa
- MARE, Laboratório Marítimo da Guia, Faculdade de Ciências da Universidade de Lisboa, Av. Nossa Senhora do Cabo, Cascais, Portugal
| | - Nicolas E Humphries
- Marine Biological Association of the United Kingdom, The Laboratory, Citadel Hill, Plymouth, United Kingdom
| | - David W Sims
- Marine Biological Association of the United Kingdom, The Laboratory, Citadel Hill, Plymouth, United Kingdom.,Centre for Biological Sciences, Highfield Campus, University of Southampton, Southampton, United Kingdom.,Ocean and Earth Science, National Oceanography Centre Southampton, Waterfront Campus, University of Southampton, Southampton, United Kingdom
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9
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Watanabe YY, Nakamura I, Chiang WC. Behavioural thermoregulation linked to foraging in blue sharks. MARINE BIOLOGY 2021; 168:161. [PMID: 34703062 PMCID: PMC8530795 DOI: 10.1007/s00227-021-03971-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 09/17/2021] [Indexed: 05/14/2023]
Abstract
UNLABELLED Large pelagic fishes often dive and surface repeatedly as if they were airbreathers, raising a question about the functions of these movements. Some species (e.g., bigeye tuna, ocean sunfish) apparently alternate foraging in deep cold waters and rewarming in shallow warm waters. However, it is unclear how prevalent this pattern is among species. Blue sharks are the widest-ranging pelagic shark with expanded vertical niches, providing a model for studying foraging-thermoregulation associations. We used electronic tags, including video cameras, to record the diving behaviour, muscle temperature, and foraging events of two blue sharks. During repeated deep dives (max. 422 m), muscle temperature changed more slowly than ambient water temperature. Sharks shifted between descents and ascents before muscle temperature reached ambient temperature, leading to a narrower range (8 °C) of muscle temperature than ambient temperature (20 °C). 2.5-h video footage showed a shark catching a squid, during which a burst swimming event was recorded. Similar swimming events, detected from the entire tag data (20 - 22 h), occurred over a wide depth range (5 - 293 m). We conclude that, instead of alternating foraging and rewarming, blue sharks at our study site forage and thermoregulate continuously in the water column. Furthermore, our comparative analyses showed that the heat exchange rates of blue sharks during the warming and cooling process were not exceptional among fishes for their body size. Thus, behavioural thermoregulation linked to foraging, rather than enhanced abilities to control heat exchange rates, is likely key to the expanded thermal niches of this ectothermic species. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s00227-021-03971-3.
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Affiliation(s)
- Yuuki Y. Watanabe
- National Institute of Polar Research, Tachikawa, Tokyo 190-8518 Japan
- Department of Polar Science, The Graduate University for Advanced Studies, SOKENDAI, Tachikawa, Tokyo 190-8518 Japan
| | - Itsumi Nakamura
- Organization for Marine Science and Technology, Nagasaki University, Nagasaki City, Nagasaki 851-2213 Japan
| | - Wei-Chuan Chiang
- Eastern Marine Biology Research Center, Fisheries Research Institute, Chenggong, Taitung County 961 Taiwan
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10
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O'Toole M, Queiroz N, Humphries NE, Sims DW, Sequeira AMM. Quantifying effects of tracking data bias on species distribution models. Methods Ecol Evol 2020. [DOI: 10.1111/2041-210x.13507] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Malcolm O'Toole
- UWA Oceans Institute and School of Biological Sciences University of Western Australia Crawley WA Australia
| | - Nuno Queiroz
- CIBIO/InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos/Research Network in Biodiversity and Evolutionary Biology Campus Agrário de Vairão Universidade do Porto Vairão Portugal
| | - Nicolas E. Humphries
- Marine Biological Association of the United KingdomThe Laboratory, Citadell Hill Plymouth UK
| | - David W. Sims
- Marine Biological Association of the United KingdomThe Laboratory, Citadell Hill Plymouth UK
- Ocean and Earth Science National Oceanography Centre Southampton Waterfront Campus University of Southampton Southampton UK
| | - Ana M. M. Sequeira
- UWA Oceans Institute and School of Biological Sciences University of Western Australia Crawley WA Australia
- Indian Ocean Marine Research Centre The University of Western Australia Crawley WA Australia
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11
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Maxwell SM, Scales KL, Bograd SJ, Briscoe DK, Dewar H, Hazen EL, Lewison RL, Welch H, Crowder LB. Seasonal spatial segregation in blue sharks (
Prionace glauca
) by sex and size class in the Northeast Pacific Ocean. DIVERS DISTRIB 2019. [DOI: 10.1111/ddi.12941] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Affiliation(s)
- Sara M. Maxwell
- School of Interdisciplinary Arts and Sciences University of Washington Bothell Washington
- Department of Biological Sciences Old Dominion University Norfolk Virginia
| | - Kylie L. Scales
- Global Change Ecology Research Group University of the Sunshine Coast Maroochydore Australia
| | - Steven J. Bograd
- NOAA Southwest Fisheries Science Center, Environmental Research Division Monterey California
- Institute of Marine Sciences University of California Santa Cruz Santa Cruz California
| | - Dana K. Briscoe
- Hopkins Marine Station Stanford University Pacific Grove California
- National Institute of Water and Atmospheric Research Nelson New Zealand
| | - Heidi Dewar
- NOAA Southwest Fisheries Science Center La Jolla California
| | - Elliott L. Hazen
- NOAA Southwest Fisheries Science Center, Environmental Research Division Monterey California
- Institute of Marine Sciences University of California Santa Cruz Santa Cruz California
| | | | - Heather Welch
- NOAA Southwest Fisheries Science Center, Environmental Research Division Monterey California
- Institute of Marine Sciences University of California Santa Cruz Santa Cruz California
| | - Larry B. Crowder
- Hopkins Marine Station Stanford University Pacific Grove California
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12
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Nykänen M, Jessopp M, Doyle TK, Harman LA, Cañadas A, Breen P, Hunt W, Mackey M, Cadhla OÓ, Reid D, Rogan E. Using tagging data and aerial surveys to incorporate availability bias in the abundance estimation of blue sharks (Prionace glauca). PLoS One 2018; 13:e0203122. [PMID: 30204764 PMCID: PMC6133345 DOI: 10.1371/journal.pone.0203122] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 08/15/2018] [Indexed: 01/08/2023] Open
Abstract
There is worldwide concern about the status of elasmobranchs, primarily as a result of overfishing and bycatch with subsequent ecosystem effects following the removal of top predators. Whilst abundant and wide-ranging, blue sharks (Prionace glauca) are the most heavily exploited shark species having suffered marked declines over the past decades, and there is a call for robust abundance estimates. In this study, we utilized depth data collected from two blue sharks using pop-up satellite archival tags, and modelled the proportion of time the sharks were swimming in the top 1-meter layer and could therefore be detected by observers conducting aerial surveys. The availability models indicated that the tagged sharks preferred surface waters whilst swimming over the continental shelf and during daytime, with a model-predicted average proportion of time spent at the surface of 0.633 (SD = 0.094) for on-shelf, and 0.136 (SD = 0.075) for off-shelf. These predicted values were then used to account for availability bias in abundance estimates for the species over a large area in the Northeast Atlantic, derived through distance sampling using aerial survey data collected in 2015 and 2016 and modelled with density surface models. Further, we compared abundance estimates corrected with model-predicted availability to uncorrected estimates and to estimates that incorporated the average time the sharks were available for detection. The mean abundance (number of individuals) corrected with modelled availability was 15,320 (CV = 0.28) in 2015 and 11,001 (CV = 0.27) in 2016. Depending on the year, these estimates were ~7 times higher compared to estimates without the bias correction, and ~3 times higher compared to the abundances corrected with average availability. When the survey area contains habitat heterogeneity that may affect surfacing patterns of animals, modelling animals' availability provides a robust alternative to correcting for availability bias and highlights the need for caution when applying "average" correction factors.
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Affiliation(s)
- Milaja Nykänen
- School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland
- Aquaculture & Fisheries Development Centre, University College Cork, Cork, Ireland
| | - Mark Jessopp
- School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland
- MaREI Centre, Environmental Research Institute, University College Cork, Cork, Ireland
| | - Thomas K. Doyle
- School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland
- Aquaculture & Fisheries Development Centre, University College Cork, Cork, Ireland
| | - Luke A. Harman
- School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland
- Aquaculture & Fisheries Development Centre, University College Cork, Cork, Ireland
| | - Ana Cañadas
- ALNILAM Research and Conservation Ltd, Madrid, Spain
| | - Patricia Breen
- School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland
- School of Geography, National University of Ireland, Galway, Ireland
| | - William Hunt
- School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland
- Aquaculture & Fisheries Development Centre, University College Cork, Cork, Ireland
| | - Mick Mackey
- School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland
- Aquaculture & Fisheries Development Centre, University College Cork, Cork, Ireland
| | - Oliver Ó Cadhla
- National Parks and Wildlife Service, Department of Culture, Heritage and the Gaeltacht, Galway, Ireland
| | - David Reid
- Marine Institute, Oranmore, Galway, Ireland
| | - Emer Rogan
- School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland
- Aquaculture & Fisheries Development Centre, University College Cork, Cork, Ireland
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13
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Santos CC, Coelho R. Migrations and habitat use of the smooth hammerhead shark (Sphyrna zygaena) in the Atlantic Ocean. PLoS One 2018; 13:e0198664. [PMID: 29874297 PMCID: PMC5991395 DOI: 10.1371/journal.pone.0198664] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Accepted: 05/23/2018] [Indexed: 11/18/2022] Open
Abstract
The smooth hammerhead shark, Sphyrna zygaena, is a cosmopolitan semipelagic shark captured as bycatch in pelagic oceanic fisheries, especially pelagic longlines targeting swordfish and/or tunas. From 2012 to 2016, eight smooth hammerheads were tagged with Pop-up Satellite Archival Tags in the inter-tropical region of the Northeast Atlantic Ocean, with successful transmissions received from seven tags (total of 319 tracking days). Results confirmed the smooth hammerhead is a highly mobile species, as the longest migration ever documented for this species (> 6600 km) was recorded. An absence of a diel vertical movement behavior was noted, with the sharks spending most of their time at surface waters (0–50 m) above 23°C. The operating depth of the pelagic longline gear was measured with Minilog Temperature and Depth Recorders, and the overlap with the species vertical distribution was calculated. The overlap is taking place mainly during the night and is higher for juveniles (~40% of overlap time). The novel information presented can now be used to contribute to the provision of sustainable management tools and serve as input for Ecological Risk Assessments for smooth hammerheads caught in Atlantic pelagic longline fisheries.
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Affiliation(s)
- Catarina C. Santos
- Portuguese Institute for the Ocean and Atmosphere, I.P., Olhão, Portugal
- * E-mail:
| | - Rui Coelho
- Portuguese Institute for the Ocean and Atmosphere, I.P., Olhão, Portugal
- Center of Marine Sciences (CCMAR), University of Algarve, Faro, Portugal
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14
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Bailleul D, Mackenzie A, Sacchi O, Poisson F, Bierne N, Arnaud‐Haond S. Large-scale genetic panmixia in the blue shark ( Prionace glauca): A single worldwide population, or a genetic lag-time effect of the "grey zone" of differentiation? Evol Appl 2018; 11:614-630. [PMID: 29875806 PMCID: PMC5978958 DOI: 10.1111/eva.12591] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Accepted: 12/12/2017] [Indexed: 12/31/2022] Open
Abstract
The blue shark Prionace glauca, among the most common and widely studied pelagic sharks, is a top predator, exhibiting the widest distribution range. However, little is known about its population structure and spatial dynamics. With an estimated removal of 10-20 million individuals per year by fisheries, the species is classified as "Near Threatened" by International Union for Conservation of Nature. We lack the knowledge to forecast the long-term consequences of such a huge removal on this top predator itself and on its trophic network. The genetic analysis of more than 200 samples collected at broad scale (from Mediterranean Sea, North Atlantic and Pacific Oceans) using mtDNA and nine microsatellite markers allowed to detect signatures of genetic bottlenecks but a nearly complete genetic homogeneity across the entire studied range. This apparent panmixia could be explained by a genetic lag-time effect illustrated by simulations of demographic changes that were not detectable through standard genetic analysis before a long transitional phase here introduced as the "population grey zone." The results presented here can thus encompass distinct explanatory scenarios spanning from a single demographic population to several independent populations. This limitation prevents the genetic-based delineation of stocks and thus the ability to anticipate the consequences of severe depletions at all scales. More information is required for the conservation of population(s) and management of stocks, which may be provided by large-scale sampling not only of individuals worldwide, but also of loci genomewide.
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Affiliation(s)
- Diane Bailleul
- IFREMER, UMR MARBEC, Station de SèteSèteFrance
- OREME – Station MarineUniversité MontpellierSèteFrance
| | - Alicia Mackenzie
- IFREMER, UMR MARBEC, Station de SèteSèteFrance
- OREME – Station MarineUniversité MontpellierSèteFrance
| | - Olivier Sacchi
- IFREMER, UMR MARBEC, Station de SèteSèteFrance
- OREME – Station MarineUniversité MontpellierSèteFrance
| | | | - Nicolas Bierne
- OREME – Station MarineUniversité MontpellierSèteFrance
- CNRS, Institut des Sciences de l'EvolutionUniversité MontpellierMontpellierFrance
| | - Sophie Arnaud‐Haond
- IFREMER, UMR MARBEC, Station de SèteSèteFrance
- OREME – Station MarineUniversité MontpellierSèteFrance
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15
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De novo assembly of the kidney and spleen transcriptomes of the cosmopolitan blue shark, Prionace glauca. Mar Genomics 2018; 37:50-53. [PMID: 33250128 DOI: 10.1016/j.margen.2017.11.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 11/23/2017] [Accepted: 11/23/2017] [Indexed: 11/23/2022]
Abstract
Cartilaginous fishes (sharks, rays and chimaeras) comprise a highly diversified group of basal vertebrates occupying a plethora of ecological aquatic niches. They represent critical components of marine ecosystems and food webs, although numerous species are threatened and almost half are poorly known. Genomic resources emerging from this basal jawed vertebrate group have offered valuable insights into the evolution of vertebrate-specific traits. Yet, the taxon remains largely understudied. Here, we generated the first high-quality de novo assembly of kidney and spleen transcriptomes of the blue shark (Prionace glauca). A total of 32,917,412 and 52,666,542 reads were obtained for spleen and kidney, respectively, using RNA-Seq Illumina technology. De novo multi-tissue assembly resulted in 97,317 unigenes with an N50 of 1975bp, in which 87,571 were assigned to a particular tissue or combination of tissues based on the sequencing read mapping. Functional annotation generated 28,564 and 19,854 open reading frames in spleen and kidney, respectively. This dataset provides a significant resource for physiological and evolutionary studies, namely into the unique osmoregulatory system of Chondrichthyes and the evolution of the immune system in vertebrates.
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16
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Coffey DM, Carlisle AB, Hazen EL, Block BA. Oceanographic drivers of the vertical distribution of a highly migratory, endothermic shark. Sci Rep 2017; 7:10434. [PMID: 28874881 PMCID: PMC5585177 DOI: 10.1038/s41598-017-11059-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Accepted: 08/17/2017] [Indexed: 12/02/2022] Open
Abstract
Salmon sharks Lamna ditropis are highly migratory, upper trophic level predators in North Pacific ecosystems. We analysed a multi-year satellite tag dataset to investigate the habitat use of female salmon sharks across their broad range in the eastern North Pacific (NEP) and identified key environmental factors that influence vertical distribution. Salmon sharks displayed remarkable plasticity in habitat use across disparate oceanographic regions in the NEP and increased utilization of deeper waters in offshore habitats. Diel shifts in vertical distribution and behaviour were consistently observed across their range and likely reflect shifts in their foraging ecology. Salmon sharks utilized a broad thermal niche and exhibited submergence behaviour, possibly for thermal refuge, when encountering sea surface temperatures outside their preferred temperature distribution. Moreover, the vertical distribution of salmon sharks indicates they were able to exploit low dissolved oxygen environments (<1–3 ml l−1), occasionally for extended periods of time in offshore habitats. However, salmon sharks generally reduced their use of deeper waters when encountering the combination of cold temperatures (<6 °C) and low dissolved oxygen concentrations (<1–3 ml l−1). Combining vertical distribution with high-resolution horizontal movements furthers our understanding of the ecological and environmental drivers of movement across short (diel) and long-term (migratory) scales.
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Affiliation(s)
- Daniel M Coffey
- Tuna Research and Conservation Center, Monterey Bay Aquarium, 886 Cannery Row, Monterey, CA, 93940, USA. .,Hawaii Institute of Marine Biology, University of Hawaii at Manoa, PO Box 1346, Kaneohe, HI, 96744, USA.
| | - Aaron B Carlisle
- Hopkins Marine Station, Stanford University, 120 Oceanview Boulevard, Pacific Grove, CA, 93950, USA
| | - Elliott L Hazen
- Environmental Research Division, Southwest Fisheries Science Center, National Oceanic and Atmospheric Administration, 99 Pacific Street, Suite 255A, Monterey, CA, 93940, USA
| | - Barbara A Block
- Hopkins Marine Station, Stanford University, 120 Oceanview Boulevard, Pacific Grove, CA, 93950, USA
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17
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Howey LA, Wetherbee BM, Tolentino ER, Shivji MS. Biogeophysical and physiological processes drive movement patterns in a marine predator. MOVEMENT ECOLOGY 2017; 5:16. [PMID: 28725435 PMCID: PMC5514520 DOI: 10.1186/s40462-017-0107-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 06/11/2017] [Indexed: 06/07/2023]
Abstract
BACKGROUND Blue sharks (Prionace glauca) are among the most abundant and widely distributed of oceanic elasmobranchs. Millions are taken annually in pelagic longline fisheries and comprise the highest component of auctioned fin weight in the international shark fin trade. Though studies of blue sharks outnumber those of other large pelagic sharks, the species' complicated and sexually segregated life history still confound current understanding of Atlantic movement patterns. Lack of detailed information regarding movement and vertical behavior continues to limit management efforts that require such data for stock assessment and sustainable catch modeling. Therefore, this study aims to describe behavioral and ecological patterns distinct to aggregating and migrating blue sharks, and compare the findings to existing Atlantic movement models. RESULTS Data collected from 23 blue sharks instrumented with pop-up satellite archival tags were used in statistical predictive regression models to investigate habitat use during a localized aggregation in the northwest Atlantic, while undergoing seasonal migrations, and with respect to environmental variables. Deployment durations ranged from 4 to 273 days, with sharks inhabiting both productive coastal waters and the open ocean, and exhibiting long-distance seasonal movements exceeding 3700 km. While aggregating on the continental shelf of the northwest Atlantic, blue sharks displayed consistent depth use independent of sex and life stage, and exhibited varied response to environmental (temperature and chlorophyll a) factors. As sharks dispersed from the aggregation site, depth use was influenced by bathymetry, latitude, demography, and presence in the Gulf Stream. Mature females were not observed at the New England tagging site, however, two mature females with recent mating wounds were captured and tagged opportunistically in The Bahamas, one of which migrated to the Mid-Atlantic Ridge. CONCLUSIONS Vertical behaviors displayed by blue sharks varied greatly among locales; depth use off the continental shelf was significantly greater, and individuals exhibited a greater frequency of deep-diving behavior, compared to periods of aggregation on the continental shelf. Sexual segregation was evident, suggesting mature and immature males, and immature females may be subjected to high levels of anthropogenic exploitation in this region during periods of aggregation. Analysis of the spatio-temporal tracks revealed that nine individuals traveled beyond the United States EEZ, including a mature female captured in The Bahamas that migrated to the Mid-Atlantic Ridge. These results reflect and augment existing Atlantic migration models, and highlight the complex, synergistic nature of factors affecting blue shark ecology and the need for a cooperative management approach in the North Atlantic.
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Affiliation(s)
- Lucy A. Howey
- Save Our Seas Shark Research Center and Guy Harvey Research Institute, Nova Southeastern University, Fort Lauderdale, Florida, USA
- Microwave Telemetry, Inc., 8835 Columbia 100 Parkway, Suites K & L, Columbia, MD USA
| | | | - Emily R. Tolentino
- Microwave Telemetry, Inc., 8835 Columbia 100 Parkway, Suites K & L, Columbia, MD USA
| | - Mahmood S. Shivji
- Save Our Seas Shark Research Center and Guy Harvey Research Institute, Nova Southeastern University, Fort Lauderdale, Florida, USA
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18
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Veríssimo A, Sampaio Í, McDowell JR, Alexandrino P, Mucientes G, Queiroz N, da Silva C, Jones CS, Noble LR. World without borders-genetic population structure of a highly migratory marine predator, the blue shark ( Prionace glauca). Ecol Evol 2017; 7:4768-4781. [PMID: 28690806 PMCID: PMC5496551 DOI: 10.1002/ece3.2987] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Revised: 03/10/2017] [Accepted: 03/21/2017] [Indexed: 01/21/2023] Open
Abstract
Highly migratory, cosmopolitan oceanic sharks often exhibit complex movement patterns influenced by ontogeny, reproduction, and feeding. These elusive species are particularly challenging to population genetic studies, as representative samples suitable for inferring genetic structure are difficult to obtain. Our study provides insights into the genetic population structure one of the most abundant and wide-ranging oceanic shark species, the blue shark Prionace glauca, by sampling the least mobile component of the populations, i.e., young-of-year and small juveniles (<2 year; N = 348 individuals), at three reported nursery areas, namely, western Iberia, Azores, and South Africa. Samples were collected in two different time periods (2002-2008 and 2012-2015) and were screened at 12 nuclear microsatellites and at a 899-bp fragment of the mitochondrial control region. Our results show temporally stable genetic homogeneity among the three Atlantic nurseries at both nuclear and mitochondrial markers, suggesting basin-wide panmixia. In addition, comparison of mtDNA CR sequences from Atlantic and Indo-Pacific locations also indicated genetic homogeneity and unrestricted female-mediated gene flow between ocean basins. These results are discussed in light of the species' life history and ecology, but suggest that blue shark populations may be connected by gene flow at the global scale. The implications of the present findings to the management of this important fisheries resource are also discussed.
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Affiliation(s)
- Ana Veríssimo
- CIBIO – U.P. – Research Center for Biodiversity and Genetic ResourcesVairãoPortugal
- Virginia Institute of Marine ScienceCollege of William and MaryGloucester PointVAUSA
| | - Íris Sampaio
- CIBIO – U.P. – Research Center for Biodiversity and Genetic ResourcesVairãoPortugal
| | - Jan R. McDowell
- Virginia Institute of Marine ScienceCollege of William and MaryGloucester PointVAUSA
| | - Paulo Alexandrino
- CIBIO – U.P. – Research Center for Biodiversity and Genetic ResourcesVairãoPortugal
| | - Gonzalo Mucientes
- CIBIO – U.P. – Research Center for Biodiversity and Genetic ResourcesVairãoPortugal
- Centro Tecnológico del MarFundación CETMARVigoSpain
| | - Nuno Queiroz
- CIBIO – U.P. – Research Center for Biodiversity and Genetic ResourcesVairãoPortugal
| | - Charlene da Silva
- Department of Agriculture, Forestry and FisheriesBranch FisheriesRogge BaySouth Africa
| | - Catherine S. Jones
- Institute of Biological and Environmental SciencesSchool of Biological SciencesUniversity of AberdeenAberdeenUK
| | - Leslie R. Noble
- Institute of Biological and Environmental SciencesSchool of Biological SciencesUniversity of AberdeenAberdeenUK
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19
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Sousa LL, López-Castejón F, Gilabert J, Relvas P, Couto A, Queiroz N, Caldas R, Dias PS, Dias H, Faria M, Ferreira F, Ferreira AS, Fortuna J, Gomes RJ, Loureiro B, Martins R, Madureira L, Neiva J, Oliveira M, Pereira J, Pinto J, Py F, Queirós H, Silva D, Sujit PB, Zolich A, Johansen TA, de Sousa JB, Rajan K. Integrated Monitoring of Mola mola Behaviour in Space and Time. PLoS One 2016; 11:e0160404. [PMID: 27494028 PMCID: PMC4975458 DOI: 10.1371/journal.pone.0160404] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Accepted: 07/19/2016] [Indexed: 11/18/2022] Open
Abstract
Over the last decade, ocean sunfish movements have been monitored worldwide using various satellite tracking methods. This study reports the near-real time monitoring of fine-scale (< 10 m) behaviour of sunfish. The study was conducted in southern Portugal in May 2014 and involved satellite tags and underwater and surface robotic vehicles to measure both the movements and the contextual environment of the fish. A total of four individuals were tracked using custom-made GPS satellite tags providing geolocation estimates of fine-scale resolution. These accurate positions further informed sunfish areas of restricted search (ARS), which were directly correlated to steep thermal frontal zones. Simultaneously, and for two different occasions, an Autonomous Underwater Vehicle (AUV) video-recorded the path of the tracked fish and detected buoyant particles in the water column. Importantly, the densities of these particles were also directly correlated to steep thermal gradients. Thus, both sunfish foraging behaviour (ARS) and possibly prey densities, were found to be influenced by analogous environmental conditions. In addition, the dynamic structure of the water transited by the tracked individuals was described by a Lagrangian modelling approach. The model informed the distribution of zooplankton in the region, both horizontally and in the water column, and the resultant simulated densities positively correlated with sunfish ARS behaviour estimator (rs = 0.184, p<0.001). The model also revealed that tracked fish opportunistically displace with respect to subsurface current flow. Thus, we show how physical forcing and current structure provide a rationale for a predator’s fine-scale behaviour observed over a two weeks in May 2014.
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Affiliation(s)
- Lara L. Sousa
- CIBIO-InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Campus Agrário de Vairão, Universidade do Porto, 4485-661 Vairão, Portugal
- Marine Biological Association of the United Kingdom, The Laboratory, Citadel Hill, Plymouth PL1 2PB, United Kingdom
| | - Francisco López-Castejón
- Department of Chemical & Environmental Engineering/Underwater Vehicles Laboratory, Universidad Politécnica de Cartagena (UPCT), Alfonso XIII, 52, E-30203, Cartagena, Spain
| | - Javier Gilabert
- Department of Chemical & Environmental Engineering/Underwater Vehicles Laboratory, Universidad Politécnica de Cartagena (UPCT), Alfonso XIII, 52, E-30203, Cartagena, Spain
| | - Paulo Relvas
- Centre for Marine Sciences (CCMAR), University of Algarve, 8005-139 Faro, Portugal
| | - Ana Couto
- CIBIO-InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Campus Agrário de Vairão, Universidade do Porto, 4485-661 Vairão, Portugal
| | - Nuno Queiroz
- CIBIO-InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Campus Agrário de Vairão, Universidade do Porto, 4485-661 Vairão, Portugal
| | - Renato Caldas
- Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Paulo Sousa Dias
- Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Hugo Dias
- Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Margarida Faria
- Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Filipe Ferreira
- Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - António Sérgio Ferreira
- Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - João Fortuna
- Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Ricardo Joel Gomes
- Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Bruno Loureiro
- Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Ricardo Martins
- Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Luis Madureira
- Oceanscan-MST, Avenida Liberdade, Polo Mar UPTEC, 4450-718 Matosinhos, Portugal
| | - Jorge Neiva
- Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Marina Oliveira
- Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - João Pereira
- Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - José Pinto
- Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Frederic Py
- Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Hugo Queirós
- Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Daniel Silva
- Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - P. B. Sujit
- Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
- IIIT Delhi, New Delhi, 110020, India
| | - Artur Zolich
- Center for Autonomous Marine Operations and Systems, Department of Engineering Cybernetics, Norwegian University of Science and Technology, Gløshaugen, Trondheim, Norway
| | - Tor Arne Johansen
- Center for Autonomous Marine Operations and Systems, Department of Engineering Cybernetics, Norwegian University of Science and Technology, Gløshaugen, Trondheim, Norway
| | - João Borges de Sousa
- Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Kanna Rajan
- Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
- Center for Autonomous Marine Operations and Systems, Department of Engineering Cybernetics, Norwegian University of Science and Technology, Gløshaugen, Trondheim, Norway
- * E-mail:
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20
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Barnes CJ, Butcher PA, Macbeth WG, Mandelman JW, Smith SDA, Peddemors VM. Movements and mortality of two commercially exploited carcharhinid sharks following longline capture and release off eastern Australia. ENDANGER SPECIES RES 2016. [DOI: 10.3354/esr00730] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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21
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Scale-dependent to scale-free: daily behavioural switching and optimized searching in a marine predator. Anim Behav 2016. [DOI: 10.1016/j.anbehav.2015.12.029] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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22
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Ocean-wide tracking of pelagic sharks reveals extent of overlap with longline fishing hotspots. Proc Natl Acad Sci U S A 2016; 113:1582-7. [PMID: 26811467 DOI: 10.1073/pnas.1510090113] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Overfishing is arguably the greatest ecological threat facing the oceans, yet catches of many highly migratory fishes including oceanic sharks remain largely unregulated with poor monitoring and data reporting. Oceanic shark conservation is hampered by basic knowledge gaps about where sharks aggregate across population ranges and precisely where they overlap with fishers. Using satellite tracking data from six shark species across the North Atlantic, we show that pelagic sharks occupy predictable habitat hotspots of high space use. Movement modeling showed sharks preferred habitats characterized by strong sea surface-temperature gradients (fronts) over other available habitats. However, simultaneous Global Positioning System (GPS) tracking of the entire Spanish and Portuguese longline-vessel fishing fleets show an 80% overlap of fished areas with hotspots, potentially increasing shark susceptibility to fishing exploitation. Regions of high overlap between oceanic tagged sharks and longliners included the North Atlantic Current/Labrador Current convergence zone and the Mid-Atlantic Ridge southwest of the Azores. In these main regions, and subareas within them, shark/vessel co-occurrence was spatially and temporally persistent between years, highlighting how broadly the fishing exploitation efficiently "tracks" oceanic sharks within their space-use hotspots year-round. Given this intense focus of longliners on shark hotspots, our study argues the need for international catch limits for pelagic sharks and identifies a future role of combining fine-scale fish and vessel telemetry to inform the ocean-scale management of fisheries.
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Letessier TB, Bouchet PJ, Meeuwig JJ. Sampling mobile oceanic fishes and sharks: implications for fisheries and conservation planning. Biol Rev Camb Philos Soc 2015; 92:627-646. [PMID: 26680116 DOI: 10.1111/brv.12246] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Revised: 11/10/2015] [Accepted: 11/12/2015] [Indexed: 11/29/2022]
Abstract
Tuna, billfish, and oceanic sharks [hereafter referred to as 'mobile oceanic fishes and sharks' (MOFS)] are characterised by conservative life-history strategies and highly migratory behaviour across large, transnational ranges. Intense exploitation over the past 65 years by a rapidly expanding high-seas fishing fleet has left many populations depleted, with consequences at the ecosystem level due to top-down control and trophic cascades. Despite increases in both CITES and IUCN Red Listings, the demographic trajectories of oceanic sharks and billfish are poorly quantified and resolved at geographic and population levels. Amongst MOFS trajectories, those of tunas are generally considered better understood, yet several populations remain either overfished or of unknown status. MOFS population trends and declines therefore remain contentious, partly due to challenges in deriving accurate abundance and biomass indices. Two major management strategies are currently recognised to address conservation issues surrounding MOFS: (i) internationally ratified legal frameworks and their associated regional fisheries management organisations (RFMOs); and (ii) spatio-temporal fishery closures, including no-take marine protected areas (MPAs). In this context, we first review fishery-dependent studies relying on data derived from catch records and from material accessible through fishing extraction, under the umbrella of RFMO-administrated management. Challenges in interpreting catch statistics notwithstanding, we find that fishery-dependent studies have enhanced the accuracy of biomass indices and the management strategies they inform, by addressing biases in reporting and non-random effort, and predicting drivers of spatial variability across meso- and oceanic scales in order to inform stock assessments. By contrast and motivated by the increase in global MPA coverage restricting extractive activities, we then detail ways in which fishery-independent methods are increasingly improving and steering management by exploring facets of MOFS ecology thus far poorly grasped. Advances in telemetry are increasingly used to explore ontogenic and seasonal movements, and provide means to consider MOFS migration corridors and residency patterns. The characterisation of trophic relationships and prey distribution through biochemical analysis and hydro-acoustics surveys has enabled the tracking of dietary shifts and mapping of high-quality foraging grounds. We conclude that while a scientific framework is available to inform initial design and subsequent implementation of MPAs, there is a shortage in the capacity to answer basic but critical questions about MOFS ecology (who, when, where?) required to track populations non-extractively, thereby presenting a barrier to assessing empirically the performance of MPA-based management for MOFS. This sampling gap is exacerbated by the increased establishment of large (>10000 km2 ) and very large MPAs (VLMPAs, >100000 km2 ) - great expanses of ocean lacking effective monitoring strategies and survey regimes appropriate to those scales. To address this shortcoming, we demonstrate the use of a non-extractive protocol to measure MOFS population recovery and MPA efficiency. We further identify technological avenues for monitoring at the VLMPA scale, through the use of spotter planes, drones, satellite technology, and horizontal acoustics, and highlight their relevance to the ecosystem-based framework of MOFS management.
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Affiliation(s)
- Tom B Letessier
- Centre for Marine Futures, Oceans Institute, The University of Western Australia (M470), 35 Stirling Highway, Crawley, Western Australia, 6009, Australia.,Institute of Zoology, Zoological Society of London, Regent's Park, London, NW1 4RY, UK
| | - Phil J Bouchet
- Centre for Marine Futures, Oceans Institute, The University of Western Australia (M470), 35 Stirling Highway, Crawley, Western Australia, 6009, Australia.,School of Animal Biology, The University of Western Australia (M470), 35 Stirling Highway, Crawley, Western Australia, 6009, Australia
| | - Jessica J Meeuwig
- Centre for Marine Futures, Oceans Institute, The University of Western Australia (M470), 35 Stirling Highway, Crawley, Western Australia, 6009, Australia.,School of Animal Biology, The University of Western Australia (M470), 35 Stirling Highway, Crawley, Western Australia, 6009, Australia
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24
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Lea JSE, Wetherbee BM, Queiroz N, Burnie N, Aming C, Sousa LL, Mucientes GR, Humphries NE, Harvey GM, Sims DW, Shivji MS. Repeated, long-distance migrations by a philopatric predator targeting highly contrasting ecosystems. Sci Rep 2015; 5:11202. [PMID: 26057337 PMCID: PMC4460898 DOI: 10.1038/srep11202] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Accepted: 03/23/2015] [Indexed: 11/09/2022] Open
Abstract
Long-distance movements of animals are an important driver of population spatial dynamics and determine the extent of overlap with area-focused human activities, such as fishing. Despite global concerns of declining shark populations, a major limitation in assessments of population trends or spatial management options is the lack of information on their long-term migratory behaviour. For a large marine predator, the tiger shark Galeocerdo cuvier, we show from individuals satellite-tracked for multiple years (up to 1101 days) that adult males undertake annually repeated, round-trip migrations of over 7,500 km in the northwest Atlantic. Notably, these migrations occurred between the highly disparate ecosystems of Caribbean coral reef regions in winter and high latitude oceanic areas in summer, with strong, repeated philopatry to specific overwintering insular habitat. Partial migration also occurred, with smaller, immature individuals displaying reduced migration propensity. Foraging may be a putative motivation for these oceanic migrations, with summer behaviour showing higher path tortuosity at the oceanic range extremes. The predictable migratory patterns and use of highly divergent ecosystems shown by male tiger sharks appear broadly similar to migrations seen in birds, reptiles and mammals, and highlight opportunities for dynamic spatial management and conservation measures of highly mobile sharks.
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Affiliation(s)
- James S E Lea
- 1] The Guy Harvey Research Institute, Nova Southeastern University Oceanographic Center, 8000 North Ocean Drive, Dania Beach, Florida 33004, United States of America [2] Marine Biological Association of the United Kingdom, The Laboratory, Citadel Hill, Plymouth PL1 2PB, UK [3] Danah Divers, Marine Research Facility, PO Box 10646, Jeddah, 21443, Saudi Arabia [4] University of Plymouth, Drake Circus, Plymouth, Devon, PL4 8AA, UK
| | - Bradley M Wetherbee
- 1] The Guy Harvey Research Institute, Nova Southeastern University Oceanographic Center, 8000 North Ocean Drive, Dania Beach, Florida 33004, United States of America [2] Department of Biological Sciences, University of Rhode Island, Kingston, Rhode Island, United States of America
| | - Nuno Queiroz
- 1] Marine Biological Association of the United Kingdom, The Laboratory, Citadel Hill, Plymouth PL1 2PB, UK [2] CIBIO - Universidade do Porto, Centro de Investigação em Biodiversidade e Recursos Genéticos, Campus Agrário de Vairão, Rua Padre Armando Quintas, 4485-668 Vairão, Portugal
| | | | | | - Lara L Sousa
- 1] Marine Biological Association of the United Kingdom, The Laboratory, Citadel Hill, Plymouth PL1 2PB, UK [2] CIBIO - Universidade do Porto, Centro de Investigação em Biodiversidade e Recursos Genéticos, Campus Agrário de Vairão, Rua Padre Armando Quintas, 4485-668 Vairão, Portugal [3] Ocean and Earth Science, National Oceanography Centre Southampton, University of Southampton, Waterfront Campus, European Way, Southampton SO14 3ZH, UK
| | - Gonzalo R Mucientes
- 1] Marine Biological Association of the United Kingdom, The Laboratory, Citadel Hill, Plymouth PL1 2PB, UK [2] Instituto de Investigaciones Marinas, CSIC, Eduardo Cabello 6, 36208, Vigo, Spain [3] CETMAR, Eduardo Cabello 6, 36208, Vigo, Spain
| | - Nicolas E Humphries
- Marine Biological Association of the United Kingdom, The Laboratory, Citadel Hill, Plymouth PL1 2PB, UK
| | - Guy M Harvey
- The Guy Harvey Research Institute, Nova Southeastern University Oceanographic Center, 8000 North Ocean Drive, Dania Beach, Florida 33004, United States of America
| | - David W Sims
- 1] Marine Biological Association of the United Kingdom, The Laboratory, Citadel Hill, Plymouth PL1 2PB, UK [2] Ocean and Earth Science, National Oceanography Centre Southampton, University of Southampton, Waterfront Campus, European Way, Southampton SO14 3ZH, UK [3] Centre for Biological Sciences, Building 85, University of Southampton, Highfield Campus, Southampton SO17 1BJ, UK
| | - Mahmood S Shivji
- The Guy Harvey Research Institute, Nova Southeastern University Oceanographic Center, 8000 North Ocean Drive, Dania Beach, Florida 33004, United States of America
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25
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Comparative analyses of animal-tracking data reveal ecological significance of endothermy in fishes. Proc Natl Acad Sci U S A 2015; 112:6104-9. [PMID: 25902489 DOI: 10.1073/pnas.1500316112] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Despite long evolutionary separations, several sharks and tunas share the ability to maintain slow-twitch, aerobic red muscle (RM) warmer than ambient water. Proximate causes of RM endothermy are well understood, but ultimate causes are unclear. Two advantages often proposed are thermal niche expansion and elevated cruising speeds. The thermal niche hypothesis is generally supported, because fishes with RM endothermy often exhibit greater tolerance to broad temperature ranges. In contrast, whether fishes with RM endothermy cruise faster, and achieve any ecological benefits from doing so, remains unclear. Here, we compiled data recorded by modern animal-tracking tools for a variety of free-swimming marine vertebrates. Using phylogenetically informed allometry, we show that both cruising speeds and maximum annual migration ranges of fishes with RM endothermy are 2-3 times greater than fishes without it, and comparable to nonfish endotherms (i.e., penguins and marine mammals). The estimated cost of transport of fishes with RM endothermy is twice that of fishes without it. We suggest that the high energetic cost of RM endothermy in fishes is offset by the benefit of elevated cruising speeds, which not only increase prey encounter rates, but also enable larger-scale annual migrations and potentially greater access to seasonally available resources.
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26
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Nakamura I, Goto Y, Sato K. Ocean sunfish rewarm at the surface after deep excursions to forage for siphonophores. J Anim Ecol 2015; 84:590-603. [PMID: 25643743 DOI: 10.1111/1365-2656.12346] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Accepted: 01/22/2015] [Indexed: 11/28/2022]
Abstract
Ocean sunfish (Mola mola) were believed to be inactive jellyfish feeders because they are often observed lying motionless at the sea surface. Recent tracking studies revealed that they are actually deep divers, but there has been no evidence of foraging in deep water. Furthermore, the surfacing behaviour of ocean sunfish was thought to be related to behavioural thermoregulation, but there was no record of sunfish body temperature. Evidence of ocean sunfish feeding in deep water was obtained using a combination of an animal-borne accelerometer and camera with a light source. Siphonophores were the most abundant prey items captured by ocean sunfish and were typically located at a depth of 50-200 m where the water temperature was <12 °C. Ocean sunfish were diurnally active, made frequently deep excursions and foraged mainly at 100-200 m depths during the day. Ocean sunfish body temperatures were measured under natural conditions. The body temperatures decreased during deep excursions and recovered during subsequent surfacing periods. Heat-budget models indicated that the whole-body heat-transfer coefficient between sunfish and the surrounding water during warming was 3-7 times greater than that during cooling. These results suggest that the main function of surfacing is the recovery of body temperature, and the fish might be able to increase heat gain from the warm surface water by physiological regulation. The thermal environment of ocean sunfish foraging depths was lower than their thermal preference (c. 16-17 °C). The behavioural and physiological thermoregulation enables the fish to increase foraging time in deep, cold water. Feeding rate during deep excursions was not related to duration or depth of the deep excursions. Cycles of deep foraging and surface warming were explained by a foraging strategy, to maximize foraging time with maintaining body temperature by vertical temperature environment.
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Affiliation(s)
- Itsumi Nakamura
- Atmosphere and Ocean Research Institute, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8564, Japan
| | - Yusuke Goto
- Atmosphere and Ocean Research Institute, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8564, Japan
| | - Katsufumi Sato
- Atmosphere and Ocean Research Institute, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8564, Japan
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27
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Miller PI, Scales KL, Ingram SN, Southall EJ, Sims DW. Basking sharks and oceanographic fronts: quantifying associations in the north‐east Atlantic. Funct Ecol 2015. [DOI: 10.1111/1365-2435.12423] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Peter I. Miller
- Plymouth Marine Laboratory Prospect Place Plymouth PL1 3DH UK
| | - Kylie L. Scales
- Plymouth Marine Laboratory Prospect Place Plymouth PL1 3DH UK
- Institute of Marine Sciences University of California Santa Cruz CA 95064 USA
| | - Simon N. Ingram
- Marine Biology and Ecology Research Centre Plymouth University Plymouth PL4 8AA UK
| | - Emily J. Southall
- The Laboratory Marine Biological Association of the United Kingdom Citadel Hill Plymouth PL1 2PB UK
| | - David W. Sims
- The Laboratory Marine Biological Association of the United Kingdom Citadel Hill Plymouth PL1 2PB UK
- Ocean and Earth Science National Oceanography Centre Southampton Waterfront Campus University of Southampton Southampton SO14 3ZH UK
- Centre for Biological Sciences Building 85 Highfield Campus University of Southampton Southampton SO17 1BJ UK
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28
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Mitchell JD, Collins KJ, Miller PI, Suberg LA. Quantifying the impact of environmental variables upon catch per unit effort of the blue shark Prionace glauca in the western English Channel. JOURNAL OF FISH BIOLOGY 2014; 85:657-670. [PMID: 24961758 DOI: 10.1111/jfb.12448] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Accepted: 05/15/2014] [Indexed: 06/03/2023]
Abstract
The effect of environmental variables on blue shark Prionace glauca catch per unit effort (CPUE) in a recreational fishery in the western English Channel, between June and September 1998-2011, was quantified using generalized additive models (GAMs). Sea surface temperature (SST) explained 1·4% of GAM deviance, and highest CPUE occurred at 16·7° C, reflecting the optimal thermal preferences of this species. Surface chlorophyll a concentration (CHL) significantly affected CPUE and caused 27·5% of GAM deviance. Additionally, increasing CHL led to rising CPUE, probably due to higher productivity supporting greater prey biomass. The density of shelf-sea tidal mixing fronts explained 5% of GAM deviance, but was non-significant, with increasing front density negatively affecting CPUE. Time-lagged frontal density significantly affected CPUE, however, causing 12·6% of the deviance in a second GAM and displayed a positive correlation. This outcome suggested a delay between the evolution of frontal features and the subsequent accumulation of productivity and attraction of higher trophic level predators, such as P. glauca.
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Affiliation(s)
- J D Mitchell
- National Oceanography Centre, University of Southampton, Waterfront Campus, European Way, Southampton SO14 3ZH, U.K
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29
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Vandeperre F, Aires-da-Silva A, Fontes J, Santos M, Serrão Santos R, Afonso P. Movements of blue sharks (Prionace glauca) across their life history. PLoS One 2014; 9:e103538. [PMID: 25119716 PMCID: PMC4131881 DOI: 10.1371/journal.pone.0103538] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Accepted: 07/04/2014] [Indexed: 11/30/2022] Open
Abstract
Spatial structuring and segregation by sex and size is considered to be an intrinsic attribute of shark populations. These spatial patterns remain poorly understood, particularly for oceanic species such as blue shark (Prionace glauca), despite its importance for the management and conservation of this highly migratory species. This study presents the results of a long-term electronic tagging experiment to investigate the migratory patterns of blue shark, to elucidate how these patterns change across its life history and to assess the existence of a nursery area in the central North Atlantic. Blue sharks belonging to different life stages (n = 34) were tracked for periods up to 952 days during which they moved extensively (up to an estimated 28.139 km), occupying large parts of the oceanic basin. Notwithstanding a large individual variability, there were pronounced differences in movements and space use across the species' life history. The study provides strong evidence for the existence of a discrete central North Atlantic nursery, where juveniles can reside for up to at least 2 years. In contrast with previously described nurseries of coastal and semi-pelagic sharks, this oceanic nursery is comparatively vast and open suggesting that shelter from predators is not its main function. Subsequently, male and female blue sharks spatially segregate. Females engage in seasonal latitudinal migrations until approaching maturity, when they undergo an ontogenic habitat shift towards tropical latitudes. In contrast, juvenile males generally expanded their range southward and apparently displayed a higher degree of behavioural polymorphism. These results provide important insights into the spatial ecology of pelagic sharks, with implications for the sustainable management of this heavily exploited shark, especially in the central North Atlantic where the presence of a nursery and the seasonal overlap and alternation of different life stages coincides with a high fishing mortality.
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Affiliation(s)
- Frederic Vandeperre
- Centre of IMAR of the University of the Azores; Department of Oceanography and Fisheries, Horta, Portugal
- LARSyS Associated Laboratory, Lisboa, Portugal
- * E-mail:
| | | | - Jorge Fontes
- Centre of IMAR of the University of the Azores; Department of Oceanography and Fisheries, Horta, Portugal
- LARSyS Associated Laboratory, Lisboa, Portugal
| | - Marco Santos
- Centre of IMAR of the University of the Azores; Department of Oceanography and Fisheries, Horta, Portugal
- LARSyS Associated Laboratory, Lisboa, Portugal
| | - Ricardo Serrão Santos
- Centre of IMAR of the University of the Azores; Department of Oceanography and Fisheries, Horta, Portugal
- LARSyS Associated Laboratory, Lisboa, Portugal
| | - Pedro Afonso
- Centre of IMAR of the University of the Azores; Department of Oceanography and Fisheries, Horta, Portugal
- LARSyS Associated Laboratory, Lisboa, Portugal
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30
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Vaudo JJ, Wetherbee BM, Harvey G, Nemeth RS, Aming C, Burnie N, Howey-Jordan LA, Shivji MS. Intraspecific variation in vertical habitat use by tiger sharks (Galeocerdo cuvier) in the western North Atlantic. Ecol Evol 2014; 4:1768-86. [PMID: 24963376 PMCID: PMC4063475 DOI: 10.1002/ece3.1053] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2013] [Revised: 03/03/2014] [Accepted: 03/11/2014] [Indexed: 11/13/2022] Open
Abstract
Tiger sharks (Galeocerdo cuvier) are a wide ranging, potentially keystone predator species that display a variety of horizontal movement patterns, making use of coastal and pelagic waters. Far less, however, is known about their vertical movements and use of the water column. We used pop-up satellite archival tags with two data sampling rates (high rate and standard rate tags) to investigate the vertical habitat use and diving behavior of tiger sharks tagged on the Puerto Rico–Virgin Islands platform and off Bermuda between 2008 and 2009. Useable data were received from nine of 14 sharks tagged, tracked over a total of 529 days. Sharks spent the majority of their time making yo-yo dives within the upper 50 m of the water column and considerable time within the upper 5 m of the water column. As a result, sharks typically occupied a narrow daily temperature range (∼2°C). Dives to greater than 200 m were common, and all sharks made dives to at least 250 m, with one shark reaching a depth of 828 m. Despite some similarities among individuals, a great deal of intraspecific variability in vertical habit use was observed. Four distinct depth distributions that were not related to tagging location, horizontal movements, sex, or size were detected. In addition, similar depth distributions did not necessitate similar dive patterns among sharks. Recognition of intraspecific variability in habitat use of top predators can be crucial for effective management of these species and for understanding their influence on ecosystem dynamics.
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Affiliation(s)
- Jeremy J Vaudo
- The Guy Harvey Research Institute, Nova Southeastern University Oceanographic Center Dania Beach, Florida
| | - Bradley M Wetherbee
- The Guy Harvey Research Institute, Nova Southeastern University Oceanographic Center Dania Beach, Florida ; Department of Biological Sciences, University of Rhode Island Kingston, Rhode Island
| | - Guy Harvey
- The Guy Harvey Research Institute, Nova Southeastern University Oceanographic Center Dania Beach, Florida
| | - Richard S Nemeth
- Center for Marine and Environmental Studies, University of the Virgin Islands Charlotte Amalie, St. Thomas, US Virgin Islands
| | - Choy Aming
- The Bermuda Shark Project Flatts, Bermuda
| | | | | | - Mahmood S Shivji
- The Guy Harvey Research Institute, Nova Southeastern University Oceanographic Center Dania Beach, Florida
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