Credit: Cassiano Psomas/Unsplash
Extremely hot years will wipe out hundreds of thousands of tonnes of fish available for catch in a country’s waters in this century, on top of projected decreases to fish stocks from long-term climate change, a new UBC study projects.
Researchers from the UBC Institute for the Oceans and Fisheries (IOF) used a complex model incorporating extreme annual ocean temperatures in Exclusive Economic Zones, where the majority of global fish catches occur, into climate-related projections for fish, fisheries and their dependent human communities.
Modelling a worst-case scenario where no action is taken to mitigate greenhouse gas emissions they projected a six per cent drop in the amount of potential catches per year and 77 per cent of exploited species are projected to decrease in biomass, or the amount of fish by weight in a given area, due to extremely hot years. These decreases are on top of those projected due to long-term decadal-scale climate change.
- In Pacific Canada, Sockeye salmon catches are projected to decrease by 26 per cent on average during a high temperature event between 2000 and 2050, an annual loss of 260 to 520 tonnes of fish. With losses due to climate change, when a temperature extreme occurs in the 2050s, the total decrease in annual catch would be more than 50 per cent or 530 to 1060 tonnes of fish.
- Peruvian anchoveta catches are projected to decline by 34 per cent during an extreme high temperature event between 2000 and 2050, or more than 900,000 tonnes per year. With climate change, a temperature extreme is projected to cost Peruvian anchoveta fisheries more than5 million tonnes of their potential catch.
- Overall, a high temperature extreme event is projected to cause a 25 per cent drop in annual revenue for Peruvian anchoveta fisheries, or a loss of around US$600 million
- Nearly three million jobs in the Indonesian fisheries-related sector are projected to be lost when a high temperature extreme occurs in their waters between 2000 and 2050.
- Some stocks are projected to increase due to these extreme events, and climate change, but not enough to mitigate the losses
During extreme ocean temperature events and on top of projected temperature changes each decade, researchers projected that fisheries’ revenues would be cut by an average of three per cent globally, and employment by two percent; a potential loss of millions of jobs.
“These extreme annual temperatures will be an additional shock to an overloaded system,” said lead author Dr. William Cheung, professor and director of UBC’s Institute for the Oceans and Fisheries (IOF). “We see that in the countries where fisheries are already weakened by long-term changes, like ocean warming and deoxygenation, adding the shock of temperature extremes will exacerbate the impacts to a point that will likely exceed the capacity for these fisheries to adapt. It’s not unlike how COVID-19 stresses the healthcare system by adding an extra burden.”
Extreme temperature events are projected to occur more frequently in the future, says co-author Dr. Thomas Frölicher, professor at the climate and environmental physics division of the University of Bern. “Today’s marine heatwaves and their severe impacts on fisheries are bellwethers of the future as these events are generating environmental conditions that long-term global warming will not create for decades.”
Some areas will be worse hit than others, the researchers found, including EEZs in the Indo-Pacific region, particularly waters around South and Southeast Asia, and Pacific Islands; the Eastern Tropical Pacific, and area which runs along the Pacific coast of the Americas; and some countries in the West African region.
In Bangladesh, where fisheries-related sectors employ one-third of the country’s workforce, an extreme marine heat event is expected to cut two per cent — about one million — of the country’s fisheries jobs, in addition to the more than six million jobs that will be lost by 2050 due to long-term climate change.
The situation is similarly grim for Ecuador, where extreme high temperature events are projected to adversely impact an additional 10 per cent, or around US$100 million, of the country’s fisheries revenue on top of the 25 per cent reduction expected by the mid-21st century.
“This study really highlights the need to develop ways to deal with marine temperature extremes, and soon,” Cheung said. “These temperature extremes are often difficult to predict in terms of when and where they occur, particularly in the hot spots with limited capacity to provide robust scientific predictions for their fisheries. We need to consider that unpredictability when we plan for adaptations to long-term climate change.”
Cheung said that active fisheries management is vital. Potential adaptations include adjusting catch quotas in years when fish stocks are suffering from extreme temperature events, or, in severe cases, shuttering fisheries so that stocks can rebuild. “We need to have mechanisms in place to deal with it,” said Cheung.
It will be important to work with those affected by such adaptation options when developing them, as some decisions could exacerbate impacts on communities’ livelihoods, as well as food and nutrition security, said co-author Dr. Colette Wabnitz, an IOF research associate and lead scientist at the Stanford Center for Ocean Solutions. “Stakeholders are diverse, and include not only industry, but also Indigenous communities, small-scale fisheries and others. They should be involved in discussions about the effects of climate change and marine heatwaves as well as the design and implementation of solutions.”
Original Article: Marine heatwaves could wipe out an extra six per cent of a country’s fish catches, costing millions their jobs
More from: University of British Columbia | University of Bern | Stanford University
The Latest Updates from Bing News & Google News
Go deeper with Bing News on:
- New study uncovers unprecedented declines in iconic kelp forests along Monterey Peninsulaon March 23, 2023 at 1:50 pm
A new study published in PLOS ONE provides novel documentation of kelp forest decline along the west coast of the U.S. and Mexico in response to the 2014–2016 record-breaking marine heatwave, along ...
- The Great Southern Reef is in more trouble than the Great Barrier Reef, find researcherson March 23, 2023 at 9:00 am
Marine heat waves are damaging reef ecosystems around Australia, but while the tropical north has received the lion's share of the attention to date, we equally need to worry about the temperate south ...
- In hot water: Ocean warming impacts growth, metabolic rate and gene activity of newly hatched clownfishon March 21, 2023 at 2:28 pm
Future ocean warming and marine heatwaves could impact the growth and development of clownfish during their earliest life stages, suggests a new study.
- Southeast humpback populations are improving, but the fallout of the Pacific marine heat wave lingerson March 21, 2023 at 11:55 am
A Glacier Bay National Park biologist says things are looking up for Southeast Alaska’s humpback whales, nearly a decade after a Pacific Ocean heat wave.
- 'The Blob' deep below may be triggered by intense seafloor heatwaveson March 20, 2023 at 1:02 pm
The first comprehensive assessment of 'bottom marine heat waves' reveals that they can be more powerful and persist longer than hot spells at the surface.
Go deeper with Google Headlines on:
[google_news title=”” keyword=”marine heatwaves” num_posts=”5″ blurb_length=”0″ show_thumb=”left”]
Go deeper with Bing News on:
Active fisheries management
- UAPB appoints new professor to aquaculture departmenton March 24, 2023 at 12:39 am
Thayer has been appointed assistant professor of aquatic habitat restoration and management for the University of Arkansas at Pine Bluff Department of Aquaculture and Fisheries ... Arkansas is very ...
- Mississippi has invested millions of dollars to save oysters. They’re disappearing anyway.on March 23, 2023 at 8:41 am
By 2015, it was clear that Mississippi oysters were in crisis. It was a devastating development for the state: As late as 2009, the oyster industry had contributed an estimated ...
- No salmon this year: California shuts down fisheryon March 22, 2023 at 5:36 pm
But this year, Davis and other salmon anglers won’t be fishing for salmon at all. In response to crashing Chinook populations, a council of West Coast fishery managers plans to cancel this year’s ...
- Tangled up in crab: Whales studied along Oregon coaston March 21, 2023 at 8:30 am
Researchers from a team led by Oregon State University have geographically located areas where whales are more likely to become entangled in fishing gear on the Oregon coast.
- Unraveling whale entanglement risk factors off Oregon Coaston March 20, 2023 at 1:42 pm
New research is beginning to unravel the times of year and locations where whales are at greatest danger of entanglement in fishing gear on the Oregon Coast.
Go deeper with Google Headlines on:
Active fisheries management
[google_news title=”” keyword=”active fisheries management” num_posts=”5″ blurb_length=”0″ show_thumb=”left”]