In hot water? Study says warming may reduce sea life by 17%

Every degree Celsius that the world’s oceans warm, the total mass of sea animals is projected to drop by 5 per cent

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 degree Celsius 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.

Much of the world relies on the oceans for food or livelihood, scientists say.

READ MORE: Canada to ban single-use plastics in 2021

“The potential ramifications of these predicted losses are huge, not just for ocean biodiversity, but because people around the world rely on ocean resources,” said University of Victoria biology professor Julia Baum, who wasn’t part of the study but says it makes sense. “Climate change has the potential to cause serious new conflicts over ocean resource use and global food security, particularly as human population continues to grow this century.”

The biggest animals in the oceans are going to be hit hardest, said study co-author Derek Tittensor, a marine ecologist at the United Nations World Conservation Monitoring Center in England.

“The good news here is that the main building blocks of marine life, plankton and bacteria may decline less heavily, the bad news is that those marine animals that we use directly, and care about most deeply, are predicted to suffer the most as climate change is working its way up the food chain,” co-author Boris Worm, a marine biologist at Dalhousie University in Canada, said in an email.

Tropical areas, already warm, will also see the biggest losses, Cheung said.

Scientists had already thought that climate change will likely reduce future ocean life, but past computer simulations looked at only part of the picture or used only one model. This study uses six different state-of-the-artcomputer models thatgive the best big picture look yet, Cheung said.

It is hard to separate past climate change impacts from those of fishing, but past studies have shown places where observed fish loss can be attributed to human-caused climate change, Chung added.

Tittensor pointed to lobsters off Maine and North Atlantic right whales as examples of creatures already being hurt by global warming hitting the ocean.

University of Georgia marine biologist Samantha Joye, who wasn’t part of the research, praised the study as meticulous and said it is also “an urgent call for action.”

“Healthy oceans are required for planetary stability,” Joye said in an email. “Aggressive global action to slow climate change is a moral imperative.”

Seth Borenstein, The Associated Press

Like us on Facebook and follow us on Twitter.

Just Posted

Body found believed to be missing Chilliwack senior with dementia

Police says case is now in the hands of the coroner

Mammoth sturgeon catch was ‘a fish of a lifetime’ for Chilliwack guide

Sturgeon was so enormous it tied for largest specimen every tagged and released in the Fraser

Chilliwack’s Riley Ashley unstoppable as Team BC wins baseball gold

Ashley clubbed six homeruns at the U-13 National Western Championships in Cloverdale.

Chilliwack’s Jude Hall selected for T12 baseball tournament

The Toronto Blue Jays Baseball Academy hosts the annual showcase event at Rogers Centre in Toronto.

Motorists urged to use caution as Ride to Conquer Cancer rolls through Chilliwack

Thousands of cyclists will be heading through Chilliwack this weekend as part of cancer fundraiser

Pickle me this: All the outrageous foods at this year’s PNE

Pickled cotton candy, deep-fried chicken skins, and ramen corndogs are just a start

New study suggests autism overdiagnosed: Canadian expert

Laurent Mottron: ‘Autistic people we test now are less and less different than typical people’

B.C. father tells judge he did not kill his young daughters

Andrew Berry pleaded not guilty to the December 2017 deaths

Trans Mountain gives contractors 30 days to get workers, supplies ready for pipeline

Crown corporation believes the expansion project could be in service by mid-2022

Fraser River sea bus proposed to hook into TransLink system

Maple Ridge councillor just wants to start discussion

Rosemount cooked diced chicken linked to listeria case in B.C.

The symptoms of listeria include vomiting, nausea, fever, muscle aches

B.C. seniors allowed more choice to stay in assisted living

Province doesn’t need to wait for a complaint to investigate care, Adrian Dix says

Retired B.C. fisherman wins record $60M Lotto Max jackpot

Joseph Katalinic won the biggest Lotto Max prize ever awarded

Most Read