Scientists say warming waters reshuffling location of marine speciesThe Canadian Press: Some marine species are migrating to oceans where they were once extinct because of warming temperatures and polar melt, according to scientists who say the shakeup poses risks to entire ecosystems...
Chris Reid, a professor of oceanography at the University of Plymouth in England, said they discovered the presence of a microscopic plankton in the North Atlantic 800,000 years after it had disappeared from that area. It would be the first evidence of a trans-Arctic migration for plankton in modern times and one of the first times in tens of thousands of years that water has flown freely between the two oceans after ice retreated from the Alaska coastline... 'They are a marker of a major transition because the last time we had an opening between the Pacific and the Atlantic was about two to three million years ago,' Reid said. 'This could have big impacts on living marine resources as well as fisheries and aquaculture.'...
He said the species shuffle could shake up the marine food web and transform the biodiversity of the Arctic and North Atlantic ecosystems... Some changes in plankton life have been linked to the collapse of some fish stocks, as well as declines in fish-eating North Sea birds, the researchers report. Changes in tiny animals called copepods are threatening the food supply for fish such as cod, herring and mackerel... Some of the tiny creatures, which are rich in oil, are being replaced by smaller and less nutritious varieties because of warming waters...
Reid said species will extend their ranges if water continues to warm and could flourish, increasing the risk of algal blooms that involve harmful phytoplankton or species like jellyfish overtaking other marine life. 'Most of the impacts are so clearly negative and the scope of change so potentially huge that, taken together, they constitute brightly flashing warning signals,' said Carlo Help, director general of the Royal Netherlands Institute for Sea Research...
Researchers predict that by 2060, as the Mediterranean warms, one-third of its 75 fish species will be threatened and six will be extinct. The findings also raise alarms about chemical cycling in the Atlantic, one of the most crucial oceans in the world for climate change and the absorption of carbon dioxide.
