As climate change causes more extreme temperature events, heat waves have the potential to hit marine environments especially hard. The impacts could be especially dire for humans, as we increasingly turn to aquaculture as the best hope to feed a global population speeding toward 10 billion people.
Researchers at Vancouver Island University are leading an investigation to study the effects of heatwaves on farmed finfish and shellfish to learn how farmers can improve crop security in an uncertain future.
“The world is changing, and we must make informed decisions to change with it successfully,” Dr. Dan Baker, a VIU Fisheries and Aquaculture Professor said. “British Columbia has a crucial part to play in providing food to Canada and the rest of the world in this future, and we believe we can help by addressing challenges in aquaculture industries hit hard by problems created by climate change and other anthropogenic activities.”
Baker, along with two other lead researchers, VIU professors Dr. Spencer Russel and Dr. Timothy Green, are designing research projects with $549,000 in funding from the Canada Foundation for Innovation and BC Knowledge Development Fund.
Green is investigating how marine heat waves can cause death in farmed oysters. Baker will examine how heat waves may alter how wild and farmed salmon and sturgeon respond and adapt to higher summer temperatures. Russell is investigating the impact on gill health of farmed salmonids.
The professors said many previous studies have focused on higher average seawater temperatures, but this general approach doesn't improve understanding on impacts to food security. By looking at aquaculture specifically, the professors hope to provide information on how different species can adapt to climate change.
The United Nations' Food and Agriculture Organization places a high value on aquaculture for the global food supply. The agency found that of the 156-million tonnes of fish products the world ate in 2018, 52 per cent already comes from aquaculture.
In B.C., just 17,500 metric tonnes of wild salmon was harvested for human consumption, compared to 87,000 metric tonnes of farmed salmon.
Provincial shellfish farming is also on the rise, but is among the first to experience impacts of climate change. In recent years harmful algae blooms and marine biotoxin incidents have spiked in frequency, while ocean acidification, caused by an increase of carbon dioxide in the environment, devastated the industry in the Pacific Northwest as young shellfish were unable to form shells.
Going forward, heatwaves lasting between a few days to a few months are expected to increase in frequency.
“By identifying how marine heatwaves alter finfish and shellfish behaviour, physiology and immune responses, we will improve our knowledge on how these warm water events increase the susceptibility of aquatic animals to disease and make significant advances in the management of finfish and shellfish health and welfare,” Russell said.