June 12, 2019 — The world’s oceans will likely lose about one-sixth of their fish and other marine life by the end of the century if climate change continues on its current path, a new study says.
Every 1.8 degrees Fahrenheit that the world’s oceans warm, the total mass of sea animals is projected to drop by 5%, according to a comprehensive computer-based study by an international team of marine biologists. And that does not include effects of fishing.
If the world’s greenhouse gas emissions stay at the present rate, that means a 17% loss of biomass — the total weight of all the marine animal life — by the year 2100, according to Tuesday’s study in the Proceedings of the National Academy of Sciences. But if the world reduces carbon pollution, losses can be limited to only about 5%, the study said.
“We will see a large decrease in the biomass of the oceans,” if the world doesn’t slow climate change, said study co-author William Cheung, a marine ecologist at the University of British Columbia. “There are already changes that have been observed.”
While warmer water is the biggest factor, climate change also produces oceans that are more acidic and have less oxygen, which also harms sea life, Cheung said.