Shrimp could be 'canary' of climate change
Fishery
HALIFAX
RICHARD FOOT
Canwest News Service
The survival of northern shrimp -one of the most important players in the food web of the North Atlantic - could be jeopardized by climate change, says a group of Canadian scientists that has discovered an extraordinary link between shrimp and the planet's changing seasons.
In an article to be published today in the journal Science, federal biologists from Canada, along with partners in the United States and Europe, reveal North Atlantic shrimp have developed the ability to expertly time the hatching of their eggs to coincide with the release of springtime ocean algae blooms baby shrimp feed on.
What makes this such an exquisite feat of nature is that the egg hatching - which occurs, on average, within days of the algae bloom - is not triggered by the bloom itself, but by ocean temperatures that dictate the incubation period of the eggs.
Shrimp populations in different Atlantic climatic zones have adapted their reproductive cycles to cope with longer or shorter incubation periods - but in each case the periods are timed to coincide with algae blooms.
In warmer parts of the ocean, off the coast of Maine for example, shrimp lay their eggs only a few months before the annual spring algae bloom. In colder parts, such as the waters off Iceland, where eggs need more time to incubate, shrimp eggs are laid almost a year before the bloom.
Yet in every zone the eggs hatch in the spring, just when the best food source for the shrimp larvae - the algae, or phytoplankton - is spreading across the sea.
"Over evolutionary time periods they've adapted to local temperatures," said Peter Koeller, one of the study's principle researchers and a biologist in Halifax with the Department of Fisheries and Oceans. "Using genetic adaptation, they have geared their mating cycle to local temperature conditions."
So important is ocean temperature to the shrimp's survival that Koeller says the species is extremely vulnerable to climate change, which could play havoc with egg incubation times.
If the surface of the North Atlantic warms up, for example, the algae may bloom earlier. But because adult shrimp mate and incubate their eggs near the ocean floor, where water temperatures may remain cold, their eggs could hatch long after their food supply has come and gone.
Koeller says climate change hasn't affected northern shrimp stocks yet, but if it it does, it would have serious consequences for the fishery.
Fishery
HALIFAX
RICHARD FOOT
Canwest News Service
The survival of northern shrimp -one of the most important players in the food web of the North Atlantic - could be jeopardized by climate change, says a group of Canadian scientists that has discovered an extraordinary link between shrimp and the planet's changing seasons.
In an article to be published today in the journal Science, federal biologists from Canada, along with partners in the United States and Europe, reveal North Atlantic shrimp have developed the ability to expertly time the hatching of their eggs to coincide with the release of springtime ocean algae blooms baby shrimp feed on.
What makes this such an exquisite feat of nature is that the egg hatching - which occurs, on average, within days of the algae bloom - is not triggered by the bloom itself, but by ocean temperatures that dictate the incubation period of the eggs.
Shrimp populations in different Atlantic climatic zones have adapted their reproductive cycles to cope with longer or shorter incubation periods - but in each case the periods are timed to coincide with algae blooms.
In warmer parts of the ocean, off the coast of Maine for example, shrimp lay their eggs only a few months before the annual spring algae bloom. In colder parts, such as the waters off Iceland, where eggs need more time to incubate, shrimp eggs are laid almost a year before the bloom.
Yet in every zone the eggs hatch in the spring, just when the best food source for the shrimp larvae - the algae, or phytoplankton - is spreading across the sea.
"Over evolutionary time periods they've adapted to local temperatures," said Peter Koeller, one of the study's principle researchers and a biologist in Halifax with the Department of Fisheries and Oceans. "Using genetic adaptation, they have geared their mating cycle to local temperature conditions."
So important is ocean temperature to the shrimp's survival that Koeller says the species is extremely vulnerable to climate change, which could play havoc with egg incubation times.
If the surface of the North Atlantic warms up, for example, the algae may bloom earlier. But because adult shrimp mate and incubate their eggs near the ocean floor, where water temperatures may remain cold, their eggs could hatch long after their food supply has come and gone.
Koeller says climate change hasn't affected northern shrimp stocks yet, but if it it does, it would have serious consequences for the fishery.
