October 17, 2016 — Marine fisheries have been estimated to support the livelihoods of 10 to 12 percent of the world’s population and generate an average of $100 billion in revenue every year. But global fisheries are facing a number of challenges: changes in markets, demographics, and over-exploitation will significantly impact global fisheries in the near future, while climate change is expected to pose a major challenge over the longer term.
A study published last month in the journal Scientific Reports explores the potential economic impacts of climate change as it affects the amount and composition of fish in marine fisheries and leads to decreased catches. Previous research has shown that global warming will cause changes in ocean temperatures, sea ice extent, salinity, and oxygen levels, among other impacts, that are likely to lead to significant shifts in the distribution range and productivity of marine species, the study notes.
“Warmer temperatures may also lead to decreases in maximum body sizes of marine fishes,” write the authors of the study, a team of scientists from the University of British Columbia (UBC). These changes will be regionally specific, as predicted species distributional shifts and changes in ocean productivity due to climate change are expected to result in increases in maximum catch potential in high latitudinal regions but decreases in the tropics. The researchers add that “These changes have large implications for people who depend on fish for food and income, and thus the contribution of fisheries to the global economy.”
In all, the UBC researchers found that global fisheries could lose approximately $10 billion in annual revenue by 2050 if climate change continues unchecked — a 10 percent decrease, which is 35 percent more than has been previously estimated.
Countries that are most dependent on fisheries to feed their populations will experience the biggest impacts, according to the study. The largest average decrease in maximum catch potential will occur in small island countries like Tuvalu, which is expected to see a 79 percent drop in annual catches in its waters, and Kiribati, which is projected to see a 70 percent decrease.
“Developing countries most dependent on fisheries for food and revenue will be hardest hit,” Vicky Lam, a postdoctoral fellow at UBC’s Institute for the Oceans and Fisheries and the study’s lead author, said in a statement. “It is necessary to implement better marine resource management plans to increase stock resilience to climate change.”
On the other hand, some developed countries, such as Greenland and Iceland, could see revenue increases as fish move into cooler waters.