Maritime life could be drained by 17%, with nearly a fifth of all living creatures in the ocean expected to disappear by the end of the century as the world will heat up three to four degree Celsius due to climate change, researchers warned.

The rising temperatures will completely wipe out shallow-water corals harboring 30% of marine life, as scientists warned that the ocean biomass will shrink by five percent with every heating degree.

Even in a "best-case" scenario of limiting warming to 2C, the ocean's biomass will drop off by five percent.

"The future of marine ecosystems will depend heavily on climate change. Measures to protect biodiversity and fisheries management will need to be revisited," a biologist at the French Institute for Development Research and one 35 experts from a dozen countries contributing to the study, Junne-Jai Shin, explained.

The study also indicated that some regions will be affected more than others, noting that marine biomass will be reduced by 40 to 50 percent in tropical zones while the concentration of life at the poles would likely rise providing new sources of food.

A recent study in Nature Climate Change noted that the number of harmful marine heatwave instances have increased by more than half since the mid-20th century.

"Up to now, the biggest threat has been overexploitation and the use of destructive fishing gear. But now, the biggest impact is switching over to climate change, and that is playing out in the sea," a marine conservation biologist and oceanographer at the University of York in England, Callum Roberts, said.

"Just as atmospheric heatwaves can destroy crops, forests and animal populations, marine heatwaves can devastate ocean ecosystems," a researcher at the Marine Biological Association in Plymouth, England, lead author Dan Smale, told AFP.

Global warming will result in the condensation of the ocean's top layer leading to warmer water and oxygen-depleted zones become deprived of life, Roberts explained.

These "dead zones" are also caused by nitrogen-rich overflow from agriculture around estuaries and along coastal areas.