10.5061/DRYAD.SN02V6X35
Ford, Michael
0000-0002-3517-1534
Northwest Fisheries Science Center
Hanson, M. Bradley
Northwest Fisheries Science Center
Emmons, Candice
Northwest Fisheries Science Center
Everett, Meredith
Northwest Fisheries Science Center
Parsons, Kim
Northwest Fisheries Science Center
Park, Linda
Northwest Fisheries Science Center
Hempelmann, Jennifer
Northwest Fisheries Science Center
Van Doornik, Donald
Northwest Fisheries Science Center
Schorr, Gregory
Marine Ecology and Telemetry Research
Jacobsen, Jeffrey
Bio-Waves, Inc.
Sears, Mark
Northwest Fisheries Science Center
Sears, Maya
Northwest Fisheries Science Center
Sneva, John
Washington Department of Fish and Wildlife
Baird, Robin
Cascadia Research
Barre, Lynne
National Marine Fisheries Service
Endangered predators and endangered prey: seasonal diet of Southern
Resident killer whales
Dryad
dataset
2021
FOS: Biological sciences
2021-01-12T00:00:00Z
2021-01-12T00:00:00Z
en
https://doi.org/10.5061/dryad.ds6gc
https://doi.org/10.1371/journal.pone.0144956
6877670041 bytes
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CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
Understanding diet is critical for conservation of endangered
predators. The Southern Resident killer whales (SRKW) (Orcinus orca) are
an endangered population occurring primarily in the west coast and inland
waters of Washington and British Columbia. Insufficient prey has been
identified as a factor limiting their recovery, so a clear understanding
of the whales’ seasonal diet is a high conservation priority. Previous
studies have shown that their summer diet in inland waters consists
primarily of Chinook salmon (Oncorhynchus tshawytscha), despite this
species’ rarity compared to some other salmonids. During other times of
year, when ranging patterns include the U.S. and Canadian west coast and
the northern and southern portions of the Salish Sea, their diet is
largely unknown. To address this data gap, we collected feces and prey
remains from October to May 2004-2017 in both the Salish Sea and U.S. west
coast waters. Using visual and genetic species identification for prey
remains and genetic approaches for fecal samples, we characterized the
diet of the SRKWs in fall, winter, and spring. Chinook salmon were
identified as an important prey item year-round, averaging ~50% of their
diet in the fall, increasing to 70-80% in the late winter/early spring,
and returning to nearly 100% in the late spring. Other salmon species and
non-salmonid fishes, also made substantial dietary contributions. The
relatively high species diversity in winter suggested a possible lack of
Chinook salmon, probably due to seasonally lower densities, based on their
proclivity to selectively consume this species in other seasons. A wide
diversity of Chinook salmon stocks were consumed, many of which are also
at risk. Although west coast samples consisted of 14 stocks, four rivers
systems accounted for 90% of the samples, predominantly the Columbia
River. Increasing the abundance of Chinook salmon stocks that inhabit the
whales’ winter range may be an effective conservation strategy for this
population.
There are 52 fasta files containing DNA sequences from a ~330bp fragment
of the mitochondrial 16s ribosomal RNA gene. These sequences were
amplified from killer whale feces collected from the wild. The file names
correspond to the sample pools described in Table S5 of the associated
publication which contains sampling information (time, location, whale ID
if known). In addition to the experimental samples, there are 9 control
samples, as described in Table S4 of the publication. Methodological
details including primers and sequencing methods are described in the
associated publication.