Tuesday February 13, 2024
Eos —
For decades, notebooks with fish facts and scale samples sat in a basement. The government of British Columbia had commissioned the collection of scales from commercially caught sockeye salmon in the Skeena River watershed from 1912 to 1947. Conservation concerns were already cropping up at that time, and the effort sought to study the animals’ life histories.
Those samples, rediscovered around 2000, show patterns of population decline in the watershed, according to a 2019 study. Now, the same team has pried yet more information from the scales—revealing that juvenile salmon in the area have gotten about 20% larger over the past century as the climate has warmed.
“We’ve been using fish scales as our window into the past,” said Michael Price, a biologist at Simon Fraser University in Burnaby, B.C., Canada. The scale collection had gone missing for 50 years. Skip McKinnell, one of the study’s coauthors, knew about the scale catalog and went looking for it. After a year of “intensive searching,” McKinnell found it at the Pacific Salmon Commission’s building in Vancouver, Price said.