Academics at the University of Alaska have discovered evidence for genetic change in pink salmon populations as a response to the environmental pressures of climate change.
In 2010, spawning pink salmon in Auke Creek, Alaska, swam upstream nearly two weeks earlier than they did forty years ago. During this time, the average temperature of the water rose by more than one degree.
The research indicates a genetic basis for this behavioural change. It appears that natural selection has acted against late-migrating individuals in the population, resulting in earlier overall migration as well as fewer late-migrating salmon.
The research provides rare evidence in support of an evolutionary response to climate change.
Fred Pribac
logged in via email @internode.on.net
Lovely! Evolution "and" climate change ... what conniptions this will inspire!
Blair Donaldson
logged in via Twitter
I'm amazed there is no comment from the climate change denial industry
Thomas Campbell
Investor
Water temperature is critical for successful salmonid egg survival. However, to confuse the issue southern hemisphere salmonid spawning is predominantly later in New Zealand (compared to 30 years ago), while there has been no trend either way in Tasmania.
Directly to the article, there is significant variation season to season on the timing of salmonid spawning, with factors including drought, flood and water temperature being key. It is critical not to take one obversation (here 2010 spawning on one stream) and suggest a trend that doesn't exist; and even worse to then link this to some cause when there is no existing trend.
Simply, if spawning stream temperatures were to rise sufficiently and quickly enough, several and eventually all salmonids would disappear. Fortunately there is no trend evidence that this is the case.
Fred Pribac
logged in via email @internode.on.net
This is not the first reported instance of observations of selection operating in an economically targetted species. My understanding is that there are other reported selective pressures due to fisheries operations particularly for gauntlet fisheries. If fish are size selected, by for instance gill net mesh size as in Australia's southern shark fishery, then there is observational evidence suggesting that growth rates through the sucseptible ages increase. The less time the fish spend growing through the gauntlet phase the more survive to breed and so the process can select for fish with altered length-at-age characteristics.