MENU CHANGES: Warm water species such as sea bass are beginning to be caught in places like the North Sea.
Image: Wikimedia Commons/Tomasz Sienicki
LONDON -- The seas around Britain are starting to teem with fish species once deemed exotic as climate change raises water temperatures, forcing the former dominant occupants to flee northward toward the Arctic and opening the way for those from the hotter south, according to marine and fisheries scientists.
Such is the extent of the migration already observed, which is expected to grow in coming decades and could even force a change in the country's fish menus. Once-local species are moving farther afield and therefore becoming more expensive to catch, while formerly foreign ones become plentiful locally and therefore presumably cheaper and easier to harvest.
"People have started calling the North Sea the crucible of climate change. It has warmed by about a degree Celsius over the last 50 to 100 years, which is something like six times faster than pretty much any marine area around the world," John Pinnegar, program director of the Marine Climate Change Centre at the government's Centre for Environment, Fisheries and Aquaculture Science, told ClimateWire.
"We have seen quite a lot of warm-water fish becoming more abundant -- things like anchovy, red mullet, sea bass -- all of which are actually quite nice to eat," he said. "Species that we traditionally got in the Bay of Biscay area are now showing up in the Irish Sea and into the North Sea. At the same time, things like cod, a cold-water fish, seem to be suffering and moving northward.
"The British have very traditional fish eating habits -- historically consuming predominantly cod in the south and haddock in the north. Not many people are used to eating red mullet and sea bass. But eating habits can change, and that is partly what adapting to climate change could mean," he added.
Pinnegar said sea bass not only has quadrupled in quantity in the seas off southern England in the past 20 years, but is now being found by anglers as far north as Scotland and is being commercially fished off the coast of Yorkshire, 250 miles north of its former northernmost range.
The chips remain, but the fish are foreigners
Pinnegar was lead author of the marine and fisheries section of a vast U.K. government report earlier this year on all aspects of the risks associated with climate change. Among other findings, the report shows significant warming of waters around the United Kingdom in studies from 1961 to 1990 across all seasons but particularly marked in autumn and winter.
Although the picture is complicated by factors such as the impact of commercial fishing, water-based recreational activities and the growth of human coastal populations, scientists say the rising acidity of the seas due to absorption of carbon dioxide from the atmosphere and changing salinity and oxygenation is having an effect on fish and shellfish.
"Sea temperatures are rising -- although it is hard to say whether this is a blip in geological terms or evidence of global warming. But with it we would expect to see some changes in the species distribution of fish," said Richard Handy, director of the Ecotoxicology Research and Innovation Centre at Plymouth University's School of Biomedical and Biological Sciences.
"As the seas warm, we would expect to see some of the species of fish we more usually associate with the warmer waters off Spain to start appearing in the U.K. There have even been reports of fishermen catching barracuda and types of shark they haven't seen before," he added.
Fish food moves north, too
While some of the colder-water species will move north to escape the heat, the rising water temperatures could also have an impact on those that remain as their metabolisms speed up with the warmth and they need to eat more. Meanwhile, the plankton and other species lower down the food chain have already moved on and so become scarcer.
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9 Comments
Add CommentI went swimming at Skegness last week and I can assure you that the Noth Sea is cold enough to freeze your nuts off.
Reply | Report Abuse | Link to thisI once read that the ocean temperatures would lag earth temps by about 6000 years, if so, did our ancestors cause that temp change way back then? Pokerplyer has a good argument.
Reply | Report Abuse | Link to thisOcean turnover is a gradual process; it is not the case that it waits however long and then flips all at once. There is also no reason to believe that every basin has the same turnover rate. Also, obviously, warming at the surface is measurable at the surface before it is measurable in the depths.
Reply | Report Abuse | Link to thisHaving said that, either what you read or what you remember is off; 6000 years is too long. You are also falling into the logic mistake of thinking that one effect can only have one cause. A -> B can be true without B -> A being true.
Plyer apparently thinks that differences in temperature and salinity have nothing to do with ocean currents. They are dependent on each other. As far as that goes, ocean heat content is rising.
http://www.skepticalscience.com/gleckler-human-fingerprint-ocean-warming.html
(Poker, Feel free to read the references for that article and let us know what the author(s) got wrong.)
Please see http://en.wikipedia.org/wiki/Thermohaline_circulation#Effects_on_global_climate
Reply | Report Abuse | Link to this[references omitted below]
"The thermohaline circulation plays an important role in supplying heat to the polar regions, and thus in regulating the amount of sea ice in these regions, although poleward heat transport outside the tropics is considerably larger in the atmosphere than in the ocean. Changes in the thermohaline circulation are thought to have significant impacts on the Earth's radiation budget. Insofar as the thermohaline circulation governs the rate at which deep waters are exposed to the surface, it may also play an important role in determining the concentration of carbon dioxide in the atmosphere. While it is often stated that the thermohaline circulation is the primary reason that Western Europe is so temperate, it has been suggested that this is largely incorrect, and that Europe is warm mostly because it lies downwind of an ocean basin, and because of the effect of atmospheric waves bringing warm air north from the subtropics. However, the underlying assumptions of this particular analysis have likewise been challenged."
You are basing your conclusion on wishful thinking. Changes in the currents are a result of cause and effect just like anything else. You injected the term 'overall' to qualify an argument that is inherently flawed. Temperature rise in one region can effect currents in another. Melting ice can cool water in one current and cause warmer water to up-well in another. It is all interrelated to temperature change and currently the trend is rising temperatures that are greater in number then falling temperatures.
Reply | Report Abuse | Link to thisEventually you are going to have to face the fact that you can't rationalize your make believe science with flawed logic. Just ask the deniers in the eastern half of the country how their denial is working out.
Apparently one of the ocean currents around the readers of this article is not the Gulf Stream but De Nial.
Reply | Report Abuse | Link to this"People have started calling the North Sea the crucible of climate change"
Reply | Report Abuse | Link to thisThen that' silly. Britain, a mote on a dot has no significance ecologically over any other mote on a dot in the world.
It's cherry picking evidence at it's most anthropological prejudice. Species ranges are shifting constantly and whether it has an impact on fish and chip consumption is ridiculous as science.
Regarding the North Sea and CO2:
Reply | Report Abuse | Link to thishttp://www.nwo.nl/nwohome.nsf/pages/NWOP_6GMG9Z_Eng
Not all seas are equal.
And anyway a crucible would be a small test area wouldn't it? If the Pacific ocean were 1°C hotter then life would be(and will be) very different.
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