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Date: | Sun, 9 May 1999 13:53:43 -0500 |
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Elevated water temperature is not the only problem associated with el nino. In
Ecuador, heavy rainfall along the coast (about ten times the normal average
precipitation during the 97/98 event) produced massive outwash of sediments
into estuaries and coastal waters suffocating all sedentary mollusks in some
areas. More than 6 meters of sediments were deposited in some parts of the
Chone Estuary; the commercial harvest of concha prieta (Anadara tuberculosa)
was wiped out there. Along the entire coast, the water has been turbid for over
2 years now. Even though we have supposedly entered a nina phase, rainfall
has been greater than normal in 1999 and the deposition of sediments has
continued. To a large extent this erosion is a result of recent deforestation
along the coastal plain, but in several locations I have found large beds of
Ostrea corteziensis beneath stands of mangrove vegetation. They appear to
have been buried during el nino events during prehistory. In fact, I have never
found living O. corteziensis in Ecuador and since they disappear abruptly from
archaeological deposits (about 1000 years ago) having previously been
abundant, I wonder if this species was not eliminated from Ecuador by some
combination of over exploitation and el nino effects.
kate
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