The Alister Hardy Foundation for Ocean Science (SAHFOS) is documenting the change in plankton through the Continuous Plankton Recorder Survey, the longest and most geographically extensive marine biological survey in the world.
SAHFOS scientists say that, in addition to the return of Neodenticula seminae, populations of tiny animals called copepods are changing too, threatening the food supply of fish such as cod, herring and mackerel, as well the many marine mammals that, in turn, prey on fish.
As the waters of the Atlantic and the North Sea warm, a valuable member of the copepod family known as Calanus finmarchicus, a rich and crucial source of oil, is being replaced by varieties that are smaller and less nutritious.
The consequences are already evident. The changes in plankton life have "been related to the collapse of some fish stocks" as well as declines in fish-eating North Sea birds, the researchers report. Harbour porpoises migrated from the northern North Sea when sand eels, a mainstay of their diet, moved poleward with the nutritious copepods.
Overall, studies show that re-arrangements of marine life composition is likely to be mixed some species could, in fact, thrive and parts of the ocean gain in biodiversity and productivity.
"But 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," says Dr. Heip.
Other findings from the project:
|Contact: Terry Collins|
Flanders Marine Institute (VLIZ)