Stark Warning on Health of Oceans
Author: Tim Radford | Published: May 4, 2017
Ocean acidification and global warming between them could severely damage the health of the oceans.
They could block the biological process that delivers nitrogen in the seawater to nourish micro-organisms. They could spark growth among the invertebrates but cause stress higher up the food web to destabilise the balance of marine life. And they could even create conditions that would make great stretches of oceans toxic.
Toxic oceans
The first two are possibilities based on laboratory experiments and warn of what could happen as the world warms, the climates change and the chemistry of the oceans continues to become more acidic. But the third may already be happening.
Marine scientists from Stony Brook University in New York state report in the Proceedings of the National Academy of Sciences that they looked at ocean temperature data and the growth of two of the most toxic algae in the North Atlantic and North Pacific oceans.
They have found that, since 1982, areas of these oceans have warmed and become more hospitable to Alexandrium and Dinophysis, two genera of micro-organism with species that manufacture neurotoxins that can cause paralytic and diarrhoetic shellfish poisoning in humans.