Seasonal variation in the lipid content of Fraser River Chinook Salmon (Oncorhynchus tshawytscha) and its implications for Southern Resident Killer Whale (Orcinus orca) prey quality
Abstract In Southern British Columbia (BC), Canada, declines in southern resident killer whale (SRKW—Orcinus orca) populations have been linked to declines in numbers and average size of their preferred prey, Chinook salmon (Oncorhynchus tshawytscha). However, the life history diversity of Chinook s...
Published in: | Scientific Reports |
---|---|
Main Authors: | , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Nature Portfolio
2023
|
Subjects: | |
Online Access: | https://doi.org/10.1038/s41598-023-28321-9 https://doaj.org/article/aba68ec23ade4aa9aec43d274df34f3f |
id |
ftdoajarticles:oai:doaj.org/article:aba68ec23ade4aa9aec43d274df34f3f |
---|---|
record_format |
openpolar |
spelling |
ftdoajarticles:oai:doaj.org/article:aba68ec23ade4aa9aec43d274df34f3f 2023-05-15T17:03:32+02:00 Seasonal variation in the lipid content of Fraser River Chinook Salmon (Oncorhynchus tshawytscha) and its implications for Southern Resident Killer Whale (Orcinus orca) prey quality Jacob E. Lerner Brian P. V. Hunt 2023-02-01T00:00:00Z https://doi.org/10.1038/s41598-023-28321-9 https://doaj.org/article/aba68ec23ade4aa9aec43d274df34f3f EN eng Nature Portfolio https://doi.org/10.1038/s41598-023-28321-9 https://doaj.org/toc/2045-2322 doi:10.1038/s41598-023-28321-9 2045-2322 https://doaj.org/article/aba68ec23ade4aa9aec43d274df34f3f Scientific Reports, Vol 13, Iss 1, Pp 1-14 (2023) Medicine R Science Q article 2023 ftdoajarticles https://doi.org/10.1038/s41598-023-28321-9 2023-03-26T01:33:13Z Abstract In Southern British Columbia (BC), Canada, declines in southern resident killer whale (SRKW—Orcinus orca) populations have been linked to declines in numbers and average size of their preferred prey, Chinook salmon (Oncorhynchus tshawytscha). However, the life history diversity of Chinook suggests that there is a need to assess stock-specific differences in energy density to evaluate prey quality as a factor in SRKW declines. In this study, we calibrated a Distell fat meter to estimate Chinook whole-body lipid content, a proxy for energy density. The fat meter was deployed at the Fraser River, BC, Chinook test fishery during 2020, collecting lipid, weight, and length measurements from 1566 genetically stock identified individuals encompassing all major Fraser River Chinook population units (management units, MUs) at river entry. We found that MU-specific lipid content increased with distance and elevation to spawning grounds and was highest in the Spring-52 (12.8%) and Summer-52 (12.7%) MUs, intermediate in the Summer-41 MU (10.8%), and lowest in the Fall-41 MU (7.3%). Lipid content also decreased by up to 6 percentage points within MUs from the beginning to end of their migration period. Our data revealed SRKWs’ most endangered prey sources, the Spring-52 and Summer-52 MUs, are also its most energy rich. It also indicated SRKWs have access to progressively lower energy density Chinook through the year, requiring up to ~ 30% more fish to meet energy demands in the fall than in the spring. Article in Journal/Newspaper Killer Whale Orca Orcinus orca Killer whale Directory of Open Access Journals: DOAJ Articles Canada British Columbia ENVELOPE(-125.003,-125.003,54.000,54.000) Fraser River ENVELOPE(-62.243,-62.243,56.619,56.619) Scientific Reports 13 1 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Medicine R Science Q |
spellingShingle |
Medicine R Science Q Jacob E. Lerner Brian P. V. Hunt Seasonal variation in the lipid content of Fraser River Chinook Salmon (Oncorhynchus tshawytscha) and its implications for Southern Resident Killer Whale (Orcinus orca) prey quality |
topic_facet |
Medicine R Science Q |
description |
Abstract In Southern British Columbia (BC), Canada, declines in southern resident killer whale (SRKW—Orcinus orca) populations have been linked to declines in numbers and average size of their preferred prey, Chinook salmon (Oncorhynchus tshawytscha). However, the life history diversity of Chinook suggests that there is a need to assess stock-specific differences in energy density to evaluate prey quality as a factor in SRKW declines. In this study, we calibrated a Distell fat meter to estimate Chinook whole-body lipid content, a proxy for energy density. The fat meter was deployed at the Fraser River, BC, Chinook test fishery during 2020, collecting lipid, weight, and length measurements from 1566 genetically stock identified individuals encompassing all major Fraser River Chinook population units (management units, MUs) at river entry. We found that MU-specific lipid content increased with distance and elevation to spawning grounds and was highest in the Spring-52 (12.8%) and Summer-52 (12.7%) MUs, intermediate in the Summer-41 MU (10.8%), and lowest in the Fall-41 MU (7.3%). Lipid content also decreased by up to 6 percentage points within MUs from the beginning to end of their migration period. Our data revealed SRKWs’ most endangered prey sources, the Spring-52 and Summer-52 MUs, are also its most energy rich. It also indicated SRKWs have access to progressively lower energy density Chinook through the year, requiring up to ~ 30% more fish to meet energy demands in the fall than in the spring. |
format |
Article in Journal/Newspaper |
author |
Jacob E. Lerner Brian P. V. Hunt |
author_facet |
Jacob E. Lerner Brian P. V. Hunt |
author_sort |
Jacob E. Lerner |
title |
Seasonal variation in the lipid content of Fraser River Chinook Salmon (Oncorhynchus tshawytscha) and its implications for Southern Resident Killer Whale (Orcinus orca) prey quality |
title_short |
Seasonal variation in the lipid content of Fraser River Chinook Salmon (Oncorhynchus tshawytscha) and its implications for Southern Resident Killer Whale (Orcinus orca) prey quality |
title_full |
Seasonal variation in the lipid content of Fraser River Chinook Salmon (Oncorhynchus tshawytscha) and its implications for Southern Resident Killer Whale (Orcinus orca) prey quality |
title_fullStr |
Seasonal variation in the lipid content of Fraser River Chinook Salmon (Oncorhynchus tshawytscha) and its implications for Southern Resident Killer Whale (Orcinus orca) prey quality |
title_full_unstemmed |
Seasonal variation in the lipid content of Fraser River Chinook Salmon (Oncorhynchus tshawytscha) and its implications for Southern Resident Killer Whale (Orcinus orca) prey quality |
title_sort |
seasonal variation in the lipid content of fraser river chinook salmon (oncorhynchus tshawytscha) and its implications for southern resident killer whale (orcinus orca) prey quality |
publisher |
Nature Portfolio |
publishDate |
2023 |
url |
https://doi.org/10.1038/s41598-023-28321-9 https://doaj.org/article/aba68ec23ade4aa9aec43d274df34f3f |
long_lat |
ENVELOPE(-125.003,-125.003,54.000,54.000) ENVELOPE(-62.243,-62.243,56.619,56.619) |
geographic |
Canada British Columbia Fraser River |
geographic_facet |
Canada British Columbia Fraser River |
genre |
Killer Whale Orca Orcinus orca Killer whale |
genre_facet |
Killer Whale Orca Orcinus orca Killer whale |
op_source |
Scientific Reports, Vol 13, Iss 1, Pp 1-14 (2023) |
op_relation |
https://doi.org/10.1038/s41598-023-28321-9 https://doaj.org/toc/2045-2322 doi:10.1038/s41598-023-28321-9 2045-2322 https://doaj.org/article/aba68ec23ade4aa9aec43d274df34f3f |
op_doi |
https://doi.org/10.1038/s41598-023-28321-9 |
container_title |
Scientific Reports |
container_volume |
13 |
container_issue |
1 |
_version_ |
1766057419646959616 |