Scientists announced on Monday that increasingly warmer oceans are the reason why thousands of marine species have migrated from the equator to the poles of the earth, which threatens marine ecosystems and the survival of people who depend on them.
They wrote in a paper published in the journal PNAS that a comparison of the data of nearly 50,000 species over three 20-year periods until 2015 showed that the outflow of tropical oceans has accelerated.
The authors of the study warned that tropical oceans have long been a disproportionate habitat for marine life, but if climate change is not stopped, this diversity will disappear.
Mark Costello, professor of marine biology at the University of Auckland, told AFP: “Global warming has changed the life of the ocean for at least 60 years.”
He added: “Our analysis shows that the number of species on the equator has fallen by about 1,500.” “This situation will continue throughout the century, but the pace will depend on whether we want to limit greenhouse gas emissions.”
The migration to the poles is much faster north of the equator than in the southern hemisphere. North of the equator, the ocean warms faster than in the southern hemisphere.
This phenomenon is more pronounced in fish than in species on the seabed.
Costello explained: “Sedentary species can only move during their floating life stages, so migration to gender needs to be passed on from generation to generation.”
In contrast, species that live on the high seas “can live with water all their lives.”
The study found that when the annual average sea temperature rises above 20-25 degrees Celsius, marine life in the tropical ocean will decrease.
The co-author of the study, David Schumann, a professor of ecology at Nelson Mandela University in Port Elizabeth, South Africa, said: “As tropical and subtropical waters warm up, species that have become extinct in tropical oceans are likely to follow their temperature. From the habitat.”
Fossil remains indicate that the same thing happened 140,000 years ago, which is the last time the global surface temperature has reached its current highest level.
According to data from the Open Marine Biodiversity Information System, statistical research has not studied how individual species will adapt to the new environment.
Previous studies have shown that, overall, species that live on the high seas have better prospects.
The impact on commercial fish in tropical oceans has not been analyzed, but it is clear which region of the world will be most affected.