Research Shows How Ocean Acidification Affects Wild Salmon

Fisheries scientists studying the impact of ocean acidification on wild salmon will host a panel discussion on Friday, November 17 from 11:45 a.m. to 12:30 p.m. at the 2017 Seattle Pacific Marine Expo to discuss their findings.

Brett Veerhusen of United Fishermen of Alaska Salmon Habitat Information Program will moderate the discussion featuring Washington Sea Grant researcher Chase Williams, NOAA oceanographer Jessica Cross, and commercial salmon harvester Amy Grondin.

Williams has been engaged, with principal investigator Evan Gallagher of the University of Washington Department of Occupational and Health Science, and others, in testing the impact of high ocean carbon dioxide levels on the sense of smell of coho salmon and sablefish, including its effects on feeding and ability to avoid predators.

Their report notes that other studies show that anticipated marine carbon dioxide concentrations can alter vital smell-mediated behaviors in fish – even repelling fish from prey and drawing them to predators. Their project is exposing coho salmon and sablefish to actual and anticipated levels of carbon dioxide and to odorant signals for food, predators and schooling.

Meg Chadsey, an ocean acidification specialist with Washington Sea Grant, is also participating in the study. What Williams is doing, she said, is testing the fish’s sense of smell for many things. He has taken juvenile coho salmon and reared them in the lab’s tanks at different levels of carbon dioxide and run them through mazes to see if they would notice and turn away from the odor of a salmon skin compound within the maze.

When extra carbon dioxide is put in the water, the salmon seemed to lose their ability to smell or respond appropriately to the predator (salmon skin compound). As concentrations of carbon dioxide increased they didn’t seem able to sense the predator or respond appropriately, she explained.