New Study Finds That Warming Oceans Stop Fish From Spawning

According to a new study, there is now a clear reason why a lot of fish are declining in numbers and it has a lot to do with the warming of our oceans due to global warming.

Warming Oceans Deter Fish Species From Spawning

It seems like global warming isn’t just affecting us humans since a new study shows that the global heating provided by climate change poses a clear danger to fish species in the ocean during the most critical time of their lives, which is whenever they spawn.

“Our findings show that, both as embryos in eggs and as adults ready to mate, fish are far more sensitive to heat than in their larval stage or as sexually mature adults outside the mating season. On the global average, for example, adults outside the mating season can survive in water that’s up to 10°C warmer than adults ready to mate, or fish eggs, can,” Flemming Dahlke, who is a marine biologist that’s working with the Alfred Wegener Institute at Bremerhaven in Germany, said.

Once confirmed by other research, these findings should help clear up some of puzzles that are associated with the numbers of fish, as well as provide clear evidence that fish are responding to global warming.

For example, fish that are in temperate zones already go through seasonal water temperatures. This is why cod shifting near the Arctic and sardines migrating to the North Sea have confused researchers in the past. And now, the latest findings made by Dr. Dahlke and his team provide another answer: Alot of fishes are already living near the limit of their heat tolerance. Simply put, the ocean is now too warm for these animals.

This is because through hundreds of thousands of years of evolution, marine and freshwater species have worked out the temperature margins that would help the process of spawning embryos. Unfortunately, the rapid warming of our waters is upsetting this balance and so fishes are looking for better waters.

As such, the study states that the reproduction of 60 percent of all fish species is likely to be affected if global warming continues.

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A “puffed up” puffer fish. Photo by Pixabay (CC0)