A critical assessment of marine predator isoscapes within the southern Indian Ocean
A critical assessment of marine predator isoscapes within the southern Indian Ocean
Background: Precise and accurate retrospective geolocation of marine predators via their tissues' isotopic composition relies on quality reference maps of relevant isotopic gradients ("isoscapes"). Additionally, a good working knowledge of any discrimination factors that may offset a marine predator's isotopic composition from baseline isotopic values, as well as tissue specific retention rates, are imperative. We provide a critical assessment of inter-specific differences among marine predator-level isoscapes within the Indian Sector of the Southern Ocean. Methods: We combined fine-scale GPS tracking data and concurrent blood plasma δ13C and δ15N values of eight seabird species (three albatross, two giant petrel and three penguin species) breeding at Marion Island to produce species- and guild-specific isoscapes. Results: Overall, our study revealed latitudinal spatial gradients in both δ13C and δ15N for far-ranging seabirds (albatrosses and giant petrels) as well as inshore-offshore gradients for near-ranging seabirds (penguins). However, at the species level, latitudinal spatial gradients were not reflected in the δ13C and δ15N isoscapes of two and three, respectively, of the five far-ranging species studied. It is therefore important when possible to estimate and apply species-specific isoscapes or have a good understanding of any factors and pathways affecting marine predators' isotopic composition when estimating the foraging distribution of marine predators via their tissues' stable isotope compositions. Conclusions: Using a multi-species approach, we provide evidence of large and regional scale systematic spatial variability of δ13C and δ15N at the base of the marine food web that propagates through trophic levels and is reflected in the isotopic composition of top predators' tissues.
Geolocation, Penguins, Procellariiformes, Seabirds, Southern Ocean, Stable isotope ecology
Carpenter-Kling, Tegan
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Pistorius, Pierre
5a585272-2721-45dd-9384-56a05a477b36
Reisinger, Ryan
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Cherel, Yves
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Connan, Maëlle
96e55fc2-588e-47ef-87d2-ae8c9a09e529
29 June 2020
Carpenter-Kling, Tegan
1d35fc56-1e0f-4d27-ab94-41bd2b876a91
Pistorius, Pierre
5a585272-2721-45dd-9384-56a05a477b36
Reisinger, Ryan
4eaf9440-48e5-41fa-853f-d46457e5444e
Cherel, Yves
be0d991b-2bda-418b-9753-bcd637d96f28
Connan, Maëlle
96e55fc2-588e-47ef-87d2-ae8c9a09e529
Carpenter-Kling, Tegan, Pistorius, Pierre, Reisinger, Ryan, Cherel, Yves and Connan, Maëlle
(2020)
A critical assessment of marine predator isoscapes within the southern Indian Ocean.
Movement Ecology, 8 (1), [29].
(doi:10.1186/s40462-020-00208-8).
Abstract
Background: Precise and accurate retrospective geolocation of marine predators via their tissues' isotopic composition relies on quality reference maps of relevant isotopic gradients ("isoscapes"). Additionally, a good working knowledge of any discrimination factors that may offset a marine predator's isotopic composition from baseline isotopic values, as well as tissue specific retention rates, are imperative. We provide a critical assessment of inter-specific differences among marine predator-level isoscapes within the Indian Sector of the Southern Ocean. Methods: We combined fine-scale GPS tracking data and concurrent blood plasma δ13C and δ15N values of eight seabird species (three albatross, two giant petrel and three penguin species) breeding at Marion Island to produce species- and guild-specific isoscapes. Results: Overall, our study revealed latitudinal spatial gradients in both δ13C and δ15N for far-ranging seabirds (albatrosses and giant petrels) as well as inshore-offshore gradients for near-ranging seabirds (penguins). However, at the species level, latitudinal spatial gradients were not reflected in the δ13C and δ15N isoscapes of two and three, respectively, of the five far-ranging species studied. It is therefore important when possible to estimate and apply species-specific isoscapes or have a good understanding of any factors and pathways affecting marine predators' isotopic composition when estimating the foraging distribution of marine predators via their tissues' stable isotope compositions. Conclusions: Using a multi-species approach, we provide evidence of large and regional scale systematic spatial variability of δ13C and δ15N at the base of the marine food web that propagates through trophic levels and is reflected in the isotopic composition of top predators' tissues.
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s40462-020-00208-8
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Accepted/In Press date: 5 May 2020
Published date: 29 June 2020
Keywords:
Geolocation, Penguins, Procellariiformes, Seabirds, Southern Ocean, Stable isotope ecology
Identifiers
Local EPrints ID: 455503
URI: http://eprints.soton.ac.uk/id/eprint/455503
PURE UUID: 8cc59cb1-2167-4ebb-988e-d59700cdda45
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Date deposited: 23 Mar 2022 17:42
Last modified: 18 Mar 2024 04:03
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Author:
Tegan Carpenter-Kling
Author:
Pierre Pistorius
Author:
Yves Cherel
Author:
Maëlle Connan
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