According to the forecast of a new study, the future of cod fishing looks uncertain because the warming of the oceans is killing young fish and making the remaining populations smaller and smaller.
It is estimated that 60% less than is expected to reach key fishing areas around Iceland and Norway if greenhouse gas emissions continue at the current level, said a group of researchers from the Alfred Wegener Institute in Bremerhaven (Germany).
Since these cold-loving fish will move further north, they will also be affected by the oceans becoming acidic, because the excess CO2 from the atmosphere dissolves in water, they wrote in their conclusions published in the journal Scientific achievements,
After warning the United Nations (UN) that world leaders should strengthen their climate commitments, scientists behind the latest research say that only the most stringent global warming targets will maintain a stable cod population.
Until recently, the cod stocks of the North Sea could have been destroyed after the number of people in four decades had fallen by more than 80 percent.
Since then, efforts to combat overfishing have resulted in a gradual recovery.
Last year, the fish was noted as stable by the Marine Stewardship Council last year for 20 years.
However, climate change is currently another major problem for global fish stocks, and it is expected that hundreds of species will be forced northward in search of cooler waters.
Cod, in particular, must appear at temperatures approaching freezing, so that their eggs develop properly.
By combining their experience in the development of fish with models of climatic conditions, the scientists behind this latest study predicted the survival rate of hatching cod.
“They show that for the“ as usual ”scenario, conditions for young Atlantic cod will especially worsen in the North Atlantic at the end of this century,” said lead author Flemming Dalkke. "In areas around Iceland and Norway, up to 60 percent less cod larvae hatch on their eggs."
Fish are especially sensitive in these early stages, and even small changes in temperature can lead to egg death or deformation in the larvae.
Polar cod is particularly prone to temperature changes. They already live in the extreme north and therefore will not be able to migrate, as the oceans are warm. Meanwhile, their Atlantic cousins will no longer be able to appear north of the Arctic Circle by 2100.
Despite their gloomy predictions, scientists found that if global warming is limited to 1.5 ° C above the pre-industrial level, the more ambitious goal set by the Paris Climate Agreement, most of the harmful effects on cod can be avoided.