Climate change has halved number of species in tropical waters, new study finds

The total number of open-water species living in tropical marine zones has halved in the last four decades, new research finds. The study, published on April 5, claims that climate change-driven factors increased the sea surface temperatures in the tropics by nearly 0.2 degree Celsius.

Many other factors including overfishing have impacted the ocean inhabitants but scientists in the study published in the Proceedings of the National Academy of Sciences found a strong correlation between decline of species and increasing temperature.

The researchers also found that species of fish plateau or decline at or above 20 degree Celsius.

Previous studies have shed light on how high temperatures are driving species of fish to cooler waters. But the new study is broader in scope, for it analysed data from 48,661 marine species that include fish, birds, mollusks, and corals that have been widely seen since 1955.

The number of species that remain attached to the seabed, including corals and sponges showed stability in the tropics between the 1970s and 2010. In fact, many of these species were found beyond the tropics, suggesting that they were able to spread out.

Essentially, species capable of physical movement are huddling to get close to cooler waters, while those attached to the seafloor are simply awaiting death.

As species of fish move away from the tropics, the coral ecosystems could perish, along with industries that rely on corals.