October 16, 2008

Clam Found to Thrive in ‘Dead Zone’ Water

A U.S. ecologist says he's found a commercially valuable species of clam thriving in oxygen-depleted waters of a so-called "dead zone" off the East Coast.

Andrew Altieri, a post-doctoral researcher at Brown University, discovered the population of quahog clams increased in hypoxic zones, defined as areas in which dissolved oxygen in the water has been depleted.

He said he determined whether quahog clams have a natural capacity to survive in oxygen-starved waters, but their predators cannot.

Altieri planted quahogs, soft-shell clams and blue mussels at four locations in Narragansett Bay. Three of the locations become oxygen-depleted during the summer and early fall.

After monitoring the quahogs, clams and mussels in 2003 and 2004, he found all three bivalve species tolerated mild hypoxic conditions, but only the quahog survived severe hypoxia.

The survival of the quahogs "was not something that we would have predicted from the conventional wisdom on dead zones or laboratory experiments alone," said Altieri, adding "you just can't say that dead zones are simply doom and gloom. Ultimately, it's a silver lining on a very dark cloud."

The research appears in the journal Ecology.