Climate change forcing fish migration

Warmer water forcing tropical fish migration toward poles

October 13, 2014

According to new research, fish are moving towards the earth’s poles in search of cooler water with better oxygenation—water with healthier habitat and more food to eat.

Climate change and warming of the world’s oceans are prompting tropical fish to mover toward cooler waters near the poles, according to a study, which predicts that a large number of fish will disappear from the tropics by 2050, if the current trend of changing temperatures continues.

Scientists at the University of British Columbia in Canada have the strongest evidence yet that climate change is driving hundreds of commercially important fish species to move away from tropics. To conduct the study, researchers used the same climate change scenarios used by the Intergovernmental Panel on Climate Change. They warned that rising temperatures will trigger a large-scale migration of fish and invertebrates to poles.

If the climatologists’ worst-case scenario comes true, and the oceans get three degrees warmer, fish will move toward the poles at an average pace of 16 miles per decade. A best-case scenario of only a single degree increase in ocean temps would see fish moving toward the poles at nine miles per decade.

“The tropics will be the overall losers,” study co-author William Cheung, associate professor at the UBC Fisheries Center, said in a press release. “The area has a high dependence on fish for food, diet and nutrition. We’ll see a loss of fish populations that are important to the fisheries and communities in these regions.”

Scientists said fish migration is more pronounced in the Arctic, which is expected to become a hot spot for species invasion. Many past studies have also showed that rising temperatures will affect the distribution of fish. But Cheung’s study offers the broadest and clearest picture of those effects. However, it’s still unclear how the invasive fish species will interact with existing ones is still unclear.

As climate change triggers the shift in fish stocks to different jurisdictions, it will create problems for international fisheries management. It’s already happening in some parts of the world.

While it is not known how the invasive species will interact with native species and ecosystems, the invasion is likely to create problems for international fisheries management as fish stocks move across currently established boundaries.

Scandinavian nations have been negotiating how they are going to deal with the changing location of Atlantic mackerel stocks.

“They could destabilize existing management agreements between countries. Norwegian fisheries are already changing noticeably,” The Canadian Press quoted Cheung as saying.

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