Canadian Study Focuses on Climate Change Effects on Fisheries

A new Canadian study on the effects of climate change on fisheries predicts that fisheries in the far north may benefit from climate change, while many other regions, particularly in the tropics, can expect revenue losses.

The University of British Columbia study quotes Rashid Sumaila, principal investigator of the Fisheries Economics Research unit at UBC, saying fisheries are already providing fewer fish and making less money than they could if overfishing was curbed. Sumaila also predicts that climate change likely will cause more losses unless such practices are curbed.

The study offers a broad view of the impact of climate changes on fisheries and their profitability. It was published on Nov. 20 online in the journal Nature Climate Change, (www.nature.com/nclimate), based in London.

Over the last century, oceans have become warmer and more acidic. Other factors, such as pollution and overfishing, have also had adverse impacts on marine species. With ocean warming, many species will move further toward the poles and into deeper water, the study said.

While fisheries in a few regions, such as the far north, may benefit from climate change, many other regions, particularly those in the tropics, can expect losses in revenue, UBC scientists said.

UBC fisheries biologist William Cheung said changes in temperature and ocean chemistry directly affect the physiology, growth, reproduction and distribution of these organisms.

“Fish in warmer waters will probably have a smaller body size, be smaller at first maturity, with higher mortality rates and be caught in different areas,” he said.

The study also found that biologically, maintaining more abundant populations can help increase the capacity of fish to adapt to environmental change. Curbing overfishing is crucial to making marine systems more robust and ready for changes that are already underway, the study found. Fish stocks will also be more robust to climate change if the combined stresses from overfishing, habitat degradation, pollution runoff, land-use transformation, competing aquatic resource uses and other anthropogenic factors are minimized, researchers said.