Alister Doyle, PlanetArk 13 Feb 09;
OSLO - Global warming will push fish stocks more than 200 km (125 miles) toward the poles by mid-century in a dislocation of ocean life, a study of more than 1,000 marine species projected.
Tropical nations were likely to suffer most as commercial fish stocks swam north or south to escape warming waters, the report said. Alaska, Greenland and Nordic nations would be among those to benefit from more fish.
"We'll see a major redistribution of many species because of climate change," said William Cheung of the University of British Columbia in Canada and the University of East Anglia in England who was lead author of the study.
"On average, fish will change their distribution by more than 40 km (25 miles) per decade in the next 50 years," he told Reuters of the report in the journal Fish and Fisheries, to be presented at a meeting in Chicago on Friday.
He said the report, written with scientists in the United States and projecting average shifts of more than 200 km over five decades, was the first to model climate impacts for more than 1,000 species such as herring, tuna, sharks or prawns.
Stocks of many species are already under pressure from over-fishing or pollution.
In the North Sea, a northward shift of cod could cut numbers by 20 percent. At the same time, North Sea stocks of the more southerly European plaice might rise by more than 10 percent.
And some cod populations off the east coast of the United States might decline by half by 2050, the report said.
TROPICS TOO HOT
"Countries in the tropics will suffer most from reductions in catches," Cheung said. The U.N. Climate Panel says emissions of greenhouse gases, mainly from burning fossil fuels, are stoking climate change such as droughts or rising seas.
Overall, Cheung said total fish catches from the world's oceans would be little changed by mid-century despite the shifts. "It's more about reshuffling the catch," he said.
The study made computer models for the movements of 1,066 species -- 836 types of fish and 230 invertebrates, such as crabs and lobsters.
Some species could die off, such as fish that thrive in cold waters and would have nowhere to go if the oceans warmed.
"Some species will face a high risk of extinction, including Striped Rock Cod in the Antarctic and St Paul Rock Lobster in the Southern Ocean," the University of East Anglia said.
Cheung said shifts were under way. Trawlers off the Western United States, for instance, were having to travel further north to catch the same fish. That led to problems, for instance, of coping with currents or rocks in unfamiliar waters.
Cheung said he hoped the study would help governments plan ways to manage fisheries. More than 190 governments plan to agree by the end of 2009 a new U.N. pact for fighting climate change to succeed the existing Kyoto Protocol.
Tropical fish swimming north because of global warming
Tropical fish are heading towards the cooler waters of the North pole, according to the results of a new study on the impact of climate change on fish.
Louise Gray, The Telegraph 12 Feb 09;
Scientists looked at the likely impact of a warming climate on the distribution of more than 1,000 species of fish around the globe.
They found fish will shift their distribution by an average of more than 40km each decade. While some fishing grounds will become richer, many species in cooler climates will go extinct.
Developing countries in the tropics will suffer the biggest loss as their fish swim north to cooler waters with Nordic countries, such as Norway, ending up with the lion's share.
The study, published in the journal Fish and Fisheries, found by 2050 the North Sea will see a 10 per cent increase in the number of plaice from Southern Europe – but will lose 20 per cent of the current Atlantic cod population.
Dr William Cheung, of the University of East Anglia, based the model on the predictions of the Intergovernmental Panel on Climate Change for temperature rises over the next century.
"Our research shows that the impact of climate change on marine biodiversity and fisheries is going to be huge," he said.
"We must act now to adapt our fisheries management and conservation policies to minimise harm to marine life and to our society.
"For example, we can use our knowledge to improve the design of marine protected areas which are adaptable to changes in distribution of the species."
Climate Change And Fisheries: US Atlantic Cod Population To Drop By Half By 2050
ScienceDaily 12 Feb 09;
Scientists have for the first time calculated the likely impact of climate change on the distribution of more than 1,000 species of fish around the globe.
The new research was carried out by scientists at the University of East Anglia (UEA), the Sea Around Us project at the University of British Columbia (UBC) and Princeton University.*
It has long been known that ocean conditions such as temperature and current patterns are changing due to climate change, and that these changes directly affect the numbers and locations of different species of fish.
Dr Cheung and his team have developed a new computer model that predicts for the first time exactly what might happen under different climate scenarios to the distribution of commercially important species – including cod, herring, sharks, groupers and prawns.
Current conservation and fisheries management measures do not account for climate-driven species distribution shifts and it is hoped this research will change this.
The disturbing results demonstrate for the first time:
* There will be a large-scale re-distribution of species, with most moving towards the Pole
* On average, fish are likely to shift their distribution by more than 40km per decade and there will be an increasing abundance of more southern species
* Developing countries in the tropics will suffer the biggest loss in catch
* Nordic countries such as Norway will gain with increased catch
* In the North Sea, the northward shift of Atlantic Cod may reduce its abundance by more than 20 per cent, while European plaice - a more southerly fish - may increase by more than 10 per cent
* In the US, there may be a 50 per cent reduction in the number of some cod populations on the east coast by 2050
* Some species will face a high risk of extinction, including Striped Rock Cod in the Antarctic and St Paul Rock Lobster in the Southern Ocean
* The invasion and local extinction of species may disrupt marine ecosystems and biodiversity
"Our research shows that the impact of climate change on marine biodiversity and fisheries is going to be huge," said Dr Cheung. "We must act now to adapt our fisheries management and conservation policies to minimise harm to marine life and to our society.
"For example, we can use our knowledge to improve the design of marine protected areas which are adaptable to changes in distribution of the species."
He said the next step would be for the research to focus on the socio-economic impact of the predicted scenarios.
*The findings were presented at the AAAS Annual Meeting in Chicago on February 13 by the paper's lead author Dr William Cheung of UEA's School of Environmental Sciences.
