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https://theconversation.com/as-chinook-salmon-get-thinner-and-fewer-southern-resident-killer-whales-struggle-to-find-enough-food-186866>
"As marine species continue to decline worldwide, the southern resident killer
whale population — which now stands at 75 individuals — along the west coast of
North America, has baffled scientists who are trying to understand why this
population is struggling.
Studied extensively since the mid-1970s, these whales are considered endangered
today. Food shortage, vessel traffic and water pollutants have affected their
fertility, body condition and social behaviour. In fact, food shortage is said
to be one of the primary causes of the declining whale population, which feed
primarily on chinook salmon. This salmon species can constitute up to 90 per
cent of the southern resident killer whale’s diet during summer.
In the late 1980s, the Canadian government applied restrictive fishing
regulations for chinook salmon to protect the population, leading to a drastic
decline in commercial fisheries. However, the chinook salmon stocks of the
Salish Sea continued to decline. Today, most chinook salmon stocks that the
southern resident killer whales feed upon are at very low levels.
As a researcher in ecosystem modelling, I have studied the predator and prey
interactions between the southern resident killer whales and their favourite
salmon preys since 2019. The declining salmon and whale numbers raised a
critical question: Is the southern resident killer whale population solely
reliant on the abundance of salmon? And, if so, since when?"
Cheers,
*** Xanni ***
--
mailto:xanni@xanadu.net Andrew Pam
http://xanadu.com.au/ Chief Scientist, Xanadu
https://glasswings.com.au/ Partner, Glass Wings
https://sericyb.com.au/ Manager, Serious Cybernetics
