Northern Shrimp Stocks Face Collapse If Warming Alters Shrimp Hatch/Algae Bloom Cycle - BBC

[hatrack]

Stocks of northern shrimp, the essential ingredient in the ubiquitous prawn cocktail, could be badly affected if ocean temperatures rise. Researchers report, in the journal Science, that shrimp eggs hatch within days of each spring phytoplankton bloom - the main food source for the larvae.

They conclude that shrimp are adapted to local temperature, which determines how long eggs take to develop. If seas warm, as predicted, shrimp stocks could collapse, the team says. The international team of scientists found that, throughout the north Atlantic - from Cape Cod in the US to to Svalbard in Norway - northern shrimp (Pandalus borealis ) eggs hatched, on average, in time with the bloom.

This is the period when food is abundant, so the larvae have a far better chance of survival. But to get the timing right, the shrimp must mate during exactly the right period during the previous year.

"They don't do this on a year by year basis - deciding to mate a week later because the algal bloom will be a week later," said Peter Koeller, a researcher from the Bedford Institute of Oceanography, who led the study. "This is on evolutionary time scales - they have adapted to local conditions."

EDIT

http://news.bbc.co.uk/2/hi/science/nature/8037888.stm