Fisheries
PERUVIAN FISHERIES and EL NIÑO
One of the world's richest fisheries is off the coast of Peru. In most years winds from the southeast push warm surface water away from the coast. In its place, upwelling brings to the surface cold water rich in nutrients. These provide nourishment for the microscopic plants know as plankton .
Plankton normally provide food for a vast community of anchovies and other fish.The fish in turn supply food for seabirds. Not only is the fish catch economically important, but the harvesting of bird excrement (guano) provides a supply of valuable fertilizer.
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Captured above are the tiny organisms known as plankton.
(Photo courtesy
http://www.paleoweb.net/pal-ges/pal-lebensweise.htm)
Every few years the pattern of air circulation of the equatorial
Pacific changes in a way that affects oceanic upwelling. This weather condition
is known as
El Niño. During El Nino, upwelling brings up warm water
with few nutrients. A serious economic consequences of El Niño is its
devastating effect on the Peruvian anchoveta fisheries. Populations of fish
and seabirds vanish and anchovy catches dwindle during El Niño.
(See our El Niño
page.)
Some biologists fear that the over fishing of the anchoveta by humans, plus
the eating of anchovies by large fish and seabirds, combined with the injurious
effects of an intense El Niño episode, like the one in 1997-98, could
reduce the anchoveta stock to such critically low numbers that recovery could
be difficult. The 1972-73 El Niño caused a serious drop in the fish
catch which took years to recover. Since then, the Peruvian government has
worked hard to regulate fishing in their territorial waters. Fortunately they
have been succesfull, and the fishery has recovered from even severe El Niños
like the one in 1988-1989.
What's a Red Tide?
Go "FORWARD" to find out!
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