Climate change will force 45% of fish stocks to move by 2100: study


As climate change increases and the oceans warm, it could have a huge impact on the fishing industry due to the displacement of fish populations from one country’s waters to another, according to a new Canadian study. .

In a study published Tuesday in the journal Global Change Biology, researchers from the University of British Columbia found that 45% of fish stocks that already cross two or more exclusive economic zones will be forced by climate change to alter their migration patterns by 2100.

And 23% of these fish stocks will have already changed their habitat by 2030.

The researchers warned in a press release that this could cause international conflict in the future.

“It’s not just a question of stocks going or arriving to new [exclusive economic zones], but stocks that are shared between countries, completely changing their dynamics,” said lead author Dr Juliano Palacios-Abrantes, who led the study at the Institute for Oceans and Fisheries (IOF) in UBC, in the release.

“We will see even more dramatic changes by 2030 and beyond, given current emission rates. Many fisheries management agreements to regulate shared stocks have been established over the past decades, with rules that apply to a world situation that is not the same as today.

Fish stock is a term for sub-populations within a species – for example, a group of salmon that have traveled the same migration path for years and passed it on to new fish born to that group is a fish stock. separate fish.

The United Nations Convention on the Law of the Sea, which was introduced in 1982, prescribes which country has rights to specific areas of the sea around them, known as an exclusive economic zone (EEZ).

Canada’s EEZ is the seventh largest in the world. An EEZ means that the country in question has exclusive rights to use the resources in those waters, including wind or water power generation, as well as fishing and exploration rights.

However, fish do not know if they are swimming in international waters or in a country’s EEZ, and if the waters they have lived in for generations become uninhabitable for them due to climate change, they will swim elsewhere. So what if a country’s fishing industry has depended on a certain species for decades, and then that species moves to a neighboring country with colder waters?

There could be tensions, the researchers warn.

In the 1980s and 1990s, the release explains, shifting salmon stocks caused conflict between the United States and Canada, contributing to the overfishing of salmon in the areas in question.

The UBC study tracked over 9,000 transboundary fish stocks that account for 80% of EEZ catches worldwide. They started tracking in 2006 and looked at how climate change had already altered their movements, extrapolating how they might still change until 2100 based on the current progression of climate change.

Although tropical waters are first affected by the migration of fish stocks, this does not mean that northern waters can rest easy. The study found that 10 stocks shared by Canada and the United States in the Pacific Ocean could change by 2033, according to projections.

“By providing estimates of the magnitude and timing of projected changes, our study offers tangible reference points around which to examine the impacts of climate change and negotiate equitable policies for sustainable management” Dr. Colette Wabnitz, senior scientist at the Center for Ocean Solutions from Stanford and co-author of the study, said in the release.

The researchers suggest that to move with the times, countries might consider developing new agreements relating to EEZ rights, such as allowing other countries to fish specific stocks in their waters if they offer a share of the benefits. Existing catch quota agreements may also need to be redesigned.

“We must accept that climate change is happening and then act quickly enough to adapt fisheries management regulations to take it into account,” said Dr Gabriel Reygondeau, co-author and associate researcher at IOF, in the press release. .

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