Trophic ecology and coastal niche partitioning of two sympatric shark species in the Azores (mid-Atlantic)
The exploitation of marine resources has caused drastic declines of many large predatory fishes. Amongst these, sharks are of major conservation concern due to their high vulnerability to overfishing and their ecological role as top predators. The 2 protected and endangered shark species tope Galeor...
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Inter Research
2024
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Online Access: | https://oceanrep.geomar.de/id/eprint/60211/ https://oceanrep.geomar.de/id/eprint/60211/1/m726p113.pdf https://www.int-res.com/abstracts/meps/v726/p113-130/ https://doi.org/10.3354/meps14487 |
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ftoceanrep:oai:oceanrep.geomar.de:60211 2024-05-12T08:08:12+00:00 Trophic ecology and coastal niche partitioning of two sympatric shark species in the Azores (mid-Atlantic) Priester, C. Robert Dierking, Jan Hansen, Thomas Abecasis, David Fontes, Jorge M. Afonso, Pedro 2024-01-11 text https://oceanrep.geomar.de/id/eprint/60211/ https://oceanrep.geomar.de/id/eprint/60211/1/m726p113.pdf https://www.int-res.com/abstracts/meps/v726/p113-130/ https://doi.org/10.3354/meps14487 en eng Inter Research https://oceanrep.geomar.de/id/eprint/60211/1/m726p113.pdf Priester, C. R., Dierking, J. , Hansen, T., Abecasis, D., Fontes, J. M. and Afonso, P. (2024) Trophic ecology and coastal niche partitioning of two sympatric shark species in the Azores (mid-Atlantic). Open Access Marine Ecology Progress Series, 726 . pp. 113-130. DOI 10.3354/meps14487 <https://doi.org/10.3354/meps14487>. doi:10.3354/meps14487 cc_by_4.0 info:eu-repo/semantics/openAccess Article PeerReviewed info:eu-repo/semantics/article 2024 ftoceanrep https://doi.org/10.3354/meps14487 2024-04-17T14:28:26Z The exploitation of marine resources has caused drastic declines of many large predatory fishes. Amongst these, sharks are of major conservation concern due to their high vulnerability to overfishing and their ecological role as top predators. The 2 protected and endangered shark species tope Galeorhinus galeus and smooth hammerhead Sphyrna zygaena use overlapping coastal areas around the globe as essential fish habitats, but data to assess their trophic ecology and niche partitioning are scarce. We provide the first comparative assessment of the trophic ecology, ontogenetic shifts, and niche partitioning of the co-occurring tope and juvenile smooth hammerhead around the Azores Islands, mid-north Atlantic, based on delta 13C, delta 15N, and delta 34S (CNS) stable isotope analysis of muscle tissue of the sharks and their putative prey species. Overall, isotopic niches of both species indicated a reliance on similar resources throughout the sampled sizes (tope: 35-190; smooth hammerhead 54-159 cm total length), with significant ontogenetic shifts. Topes displayed a gradual shift to higher trophic levels and a more generalist diet with increasing size (increasing delta 15N values and isotopic niche volumes, respectively), whereas smooth hammerhead diet shifted towards prey with lower delta 34S at a constant trophic level and a more specialized diet than tope of comparable body size (decreasing delta 34S and constant delta 15N and delta 13C values, respectively). Our results indicate contrasting ontogenetic shifts in delta 13C and delta 34S along with pronounced differences between niche overlap of life stages pointing to intra- and interspecific niche partitioning of habitat and prey. Article in Journal/Newspaper North Atlantic OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Marine Ecology Progress Series 726 113 130 |
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Open Polar |
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OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
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ftoceanrep |
language |
English |
description |
The exploitation of marine resources has caused drastic declines of many large predatory fishes. Amongst these, sharks are of major conservation concern due to their high vulnerability to overfishing and their ecological role as top predators. The 2 protected and endangered shark species tope Galeorhinus galeus and smooth hammerhead Sphyrna zygaena use overlapping coastal areas around the globe as essential fish habitats, but data to assess their trophic ecology and niche partitioning are scarce. We provide the first comparative assessment of the trophic ecology, ontogenetic shifts, and niche partitioning of the co-occurring tope and juvenile smooth hammerhead around the Azores Islands, mid-north Atlantic, based on delta 13C, delta 15N, and delta 34S (CNS) stable isotope analysis of muscle tissue of the sharks and their putative prey species. Overall, isotopic niches of both species indicated a reliance on similar resources throughout the sampled sizes (tope: 35-190; smooth hammerhead 54-159 cm total length), with significant ontogenetic shifts. Topes displayed a gradual shift to higher trophic levels and a more generalist diet with increasing size (increasing delta 15N values and isotopic niche volumes, respectively), whereas smooth hammerhead diet shifted towards prey with lower delta 34S at a constant trophic level and a more specialized diet than tope of comparable body size (decreasing delta 34S and constant delta 15N and delta 13C values, respectively). Our results indicate contrasting ontogenetic shifts in delta 13C and delta 34S along with pronounced differences between niche overlap of life stages pointing to intra- and interspecific niche partitioning of habitat and prey. |
format |
Article in Journal/Newspaper |
author |
Priester, C. Robert Dierking, Jan Hansen, Thomas Abecasis, David Fontes, Jorge M. Afonso, Pedro |
spellingShingle |
Priester, C. Robert Dierking, Jan Hansen, Thomas Abecasis, David Fontes, Jorge M. Afonso, Pedro Trophic ecology and coastal niche partitioning of two sympatric shark species in the Azores (mid-Atlantic) |
author_facet |
Priester, C. Robert Dierking, Jan Hansen, Thomas Abecasis, David Fontes, Jorge M. Afonso, Pedro |
author_sort |
Priester, C. Robert |
title |
Trophic ecology and coastal niche partitioning of two sympatric shark species in the Azores (mid-Atlantic) |
title_short |
Trophic ecology and coastal niche partitioning of two sympatric shark species in the Azores (mid-Atlantic) |
title_full |
Trophic ecology and coastal niche partitioning of two sympatric shark species in the Azores (mid-Atlantic) |
title_fullStr |
Trophic ecology and coastal niche partitioning of two sympatric shark species in the Azores (mid-Atlantic) |
title_full_unstemmed |
Trophic ecology and coastal niche partitioning of two sympatric shark species in the Azores (mid-Atlantic) |
title_sort |
trophic ecology and coastal niche partitioning of two sympatric shark species in the azores (mid-atlantic) |
publisher |
Inter Research |
publishDate |
2024 |
url |
https://oceanrep.geomar.de/id/eprint/60211/ https://oceanrep.geomar.de/id/eprint/60211/1/m726p113.pdf https://www.int-res.com/abstracts/meps/v726/p113-130/ https://doi.org/10.3354/meps14487 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
https://oceanrep.geomar.de/id/eprint/60211/1/m726p113.pdf Priester, C. R., Dierking, J. , Hansen, T., Abecasis, D., Fontes, J. M. and Afonso, P. (2024) Trophic ecology and coastal niche partitioning of two sympatric shark species in the Azores (mid-Atlantic). Open Access Marine Ecology Progress Series, 726 . pp. 113-130. DOI 10.3354/meps14487 <https://doi.org/10.3354/meps14487>. doi:10.3354/meps14487 |
op_rights |
cc_by_4.0 info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.3354/meps14487 |
container_title |
Marine Ecology Progress Series |
container_volume |
726 |
container_start_page |
113 |
op_container_end_page |
130 |
_version_ |
1798851127016423424 |