Highly-venomous jelly fish closer to British waters as global warming causes biggest shift of marine life in two million years


Moving closer: The highly venomous Portuguese Man o' War jellyfish is increasingly being found in UK waters

Moving closer: The highly venomous Portuguese Man o' War jellyfish is increasingly being found in UK waters

The global warming of sea waters is causing the biggest movement of marine species in two million years, according to a huge new international study by 17 different science institutes

Among the changes recorded by scientists contributing to Project Clamer is the fact that huge blooms of a venomous warm-water species of jellyfish are massing in the North Atlantic.

The Pelagia noctiluca 'dominates in many areas and outbreaks have become an annual event, forcing the closing of beaches,' says the report.

'This form of jellyfish is a gluttonous predator of juvenile fish, so researchers consider its spread a harmful trend.'

However, there was further bad news as the report also warned that the highly-venomous Portuguese Man O'War is also moving closer.  

Physalia physalis, a jellyfish-like creature usually found in subtropical waters, is more regularly being discovered in northern Atlantic waters.

The research is to be published this year by Project Clamer, a major collaboration between 17 institutes on climate change and the oceans.

Among the other discoveries in worldwide waters, it was noted that aa 43-foot gray whale was spotted off the Israeli town of Herzliya last year.

Scientists came to a startling conclusion that it must have wandered across the normally icebound route above Canada, where warm weather had briefly opened a clear channel three years earlier.

On a microscopic level, scientists also have found plankton in the North Atlantic where it had not existed for at least 800,000 years.

GLOBAL WARNING: MORE FINDINGS FROM PROJECT CLAMER 

The cod population has plummeted throughout the North Atlantic, largely due to over-fishing so far, but rising sea temperatures will prevent stocks from replenishing.

• In the North Sea, several fish species - including sea bass, mullet, solenette and scaldfish - are moving northward and increasing in numbers as the water warms. This 'will affect the North Sea food chain.

• Changes in temperature and other conditions mean some prey species are no longer available when their predators need them.

• The Baltic Sea is expected to become less salty, which would reduce the number of fish species.

• In enclosed seas, species that require cooler conditions might have nowhere to go when the waters warm. Researchers predict that by 2060, as the Mediterranean warms, one-third of its 75 fish species will be threatened and six will be extinct.

• A toxic form of phytoplankton, known as dinoflagellates, is rising in abundance and moving steadily eastward across the Atlantic toward Scandinavia.

• Warmer temperatures and stratification of the water are allowing microscopic organic matter to form massive blobs in the Mediterranean Sea. This noxious material harbours bacteria and viruses that could kill fish.

The whale's odyssey and the surprising appearance of the plankton indicates a migration of species through the Northwest Passage, a worrying sign of how global warming is affecting animals and plants in the oceans as well as on land.

'The implications are enormous. It's a threshold that has been crossed,' said Philip C. Reid, of the Alister Hardy Foundation for Ocean Science in Plymouth.

'It's an indication of the speed of change that is taking place in our world in the present day because of climate change.'

Mr Reid said the last time the world witnessed such a major incursion from the Pacific was two million years ago, which had 'a huge impact on the North Atlantic,' driving some species to extinction as the newcomers dominated the competition for food.

Mr Reid's study of plankton and the research on the whale, co-authored by Aviad Scheinin of the Israel Marine Mammal Research and Assistance Center, are among nearly 300 scientific papers written over the last 13 years that are being synthesized and published this year by Project Clamer.

The Northwest Passage, the route through the frigid archipelago from Alaska across northern Canada, has been ice-free from one end to the other only twice in recorded history, in 1998 and 2007.

But the ice pack is retreating farther and more frequently during the summers.

Plankton that had previously been found only in Atlantic sea bed cores from 800,000 years ago appeared in the Labrador Sea in 1999 - and then in massive numbers in the Gulf of St. Lawrence two years later.

Now it has established itself as far south as the New York coast, said Mr Reid.

The highly endangered gray whale sighted off the Israeli coast in May 2010 belonged to a species that was hunted to extinction in the Atlantic by the mid-1700s.

The same animal - identified by unique markings on its fluke, or tail fin - appeared off the Spanish coast 22 days later, and has not been reported seen since.

Though it was difficult to draw conclusions from one whale, the researchers said its presence in the Mediterranean 'coincides with a shrinking of Arctic Sea ice due to climate change and suggests that climate change may allow gray whales to re-colonize the North Atlantic.'

That may be good for the whales, but other aspects of the ice melt could be harmful to the oceans' biosystems, the scientists warn.

Plankton is normally the bottom of the marine food chain, but some are more nutritious than others.

Plankton changes have been blamed for the collapse of some fish stocks and threats to fish-eating birds in the North Sea, the studies show.

The migration of a solitary whale and two species of plankton is not of much concern so far, Reid said.

'It's the potential for further ones to come through if the Arctic opens. That's the key message.'

Washed up: A Portuguese Man o'War - Physalia physalis - lies on the sand in the Belize Caribbean Sea, where it is more often at home

Washed up: A Portuguese Man o'War - Physalia physalis - lies on the sand in the Belize Caribbean Sea, where it is more often at home