A newly published study has produced the most evidence yet that valuable fish species are being forced north and south towards both of the Earth’s poles by climate change and the continuous rising of ocean temperatures. The study predicts that many numbers of fish species will be affected if temperature increases are allowed to continue at current rates and that a large percentage of fish species may disappear from warmer tropical waters as early as 2050.
During the study, researchers from the University of British Columbia (UBC) utilized climate change scenarios previously used by the Intergovernmental Panel of Climate Change (IPCC) in order to predict the likelihood of dramatic changes in the habitat of fish and invertebrate species. According to the results, the current best-case scenario which assumes ocean temperatures will warm one degree Celsius by 2100, will result in fish species retreating to cooler waters at around nine miles every decade. The worst-case scenario, an ocean temperature increase of three degrees by the end of the century, will cause fish species to shift as much as 16 miles every decade.
The results of the study show in either scenario that the warmer tropical waters will suffer as valuable fish species shift their habitats further from the equator with continuing climate change. This could spell disaster for the many poorer subtropical nations that rely heavily on fisheries for food and nutrition, as well as commercial export.
While disaster looms for the tropics, the Arctic and Antarctic regions could see an increase in harvestable fish species as the ocean continues to warm, generating new opportunities for fisheries in North America and Europe. While it isn’t yet clear what impact a host of new fish species could have on the cooler water, some researchers have suggested that the migration of foreign species into the area could threaten existing populations as species begin to compete for resources.
Other possible problems may arise as migrating fish populations cross existing jurisdictional lines between countries. This has already occurred in Scandinavia, where authorities from several countries are attempting to negotiate ways to handle the shifting habitats of Atlantic Mackerel.
The study, which examined over 800 commercially harvested fish species, including tuna, cod, herring and halibut, is among the first to provide serious evidence of fish movements as a result of climate change. William Cheung, the co-author of the study, stated that the research has helped to show how the increased effects of climate change on fisheries and other natural resources needs to be addressed immediately.
Cheung also expressed the need for governments to allow scientists to study the effects of new fish stocks in cooler waters before rushing to exploit them. According to Cheung, the environmental effects of shifting fish stocks due to climate change are still unknown and a conservative and cautious approach is needed to ensure there is no danger of collapse to the fisheries industry. He praised a United States decision which enacted a moratorium on any new commercial fishing in Arctic waters. As of yet there is no similar ban enacted in nearby Canadian waters.
By Mathew Channer