Brown University researchers say heavy rains and hot weather in the summer of 2001 led to the deaths of an estimated 4.5 billion mussels.

01:00 AM EDT on Wednesday, April 12, 2006

BY PETER B. LORD
Journal Environment Writer

Summer after summer, algae blooms and fish kills in Narragansett Bay line beaches with dead marine life and taint the coast with foul odors. Now, a Brown University study has detailed more damage: the loss of billions of mussels that died largely out of sight, on the Bay's bottom.

Researchers estimate 4.5 billion mussels were killed in nine reefs in the middle of Narragansett Bay. The mussels had been so prevalent they could filter all the waters of the Bay in 20 days, but after the die-off, the filtering capacity dropped by 75 percent.

The mussel deaths occurred in the summer of 2001, when heavy rains and hot weather caused algae blooms more prolific than some observers had seen in years. Oxygen is drawn from the water when algae dies off, creating low oxygen or hypoxic conditions that kill additional marine life.

The obvious results in 2001 were foamy, brown, sludge-like material washing ashore around the Bay and fish kills in Greenwich Bay and off Cranston. Most of the dead mussels did not wash ashore.

The loss of mussels was made public yesterday, following publication of a paper on the die-off in Ecology, the scientific journal of the Ecological Society of America. Authors are Andrew H. Altieri, a recent graduate with a doctorate from Brown's department of ecology and evolutionary biology, and Jon D. Witman, an associate professor in the department.

The study coincides with renewed efforts by the Carcieri administration to revive a new Narragansett Bay management program that was kick-started by a massive fish kill in Greenwich Bay in 2003.

The fish kill prompted studies that led both houses of the General Assembly to endorse legislation mandating new ecosystem-based management protocols. New committees were set up to advise on science, water quality monitoring and economics.

But in the last year, progress stalled for two reasons: the Senate did not ratify Governor Carcieri's appointment of a chairman for the new Bay coordination team, and it cut the $1 million proposed for water-quality monitoring that is considered critical to managing the Bay.

"My understanding is the process has been plagued by the fact that there is no chair," said Robert Ballou, chief of staff at the state Department of Environmental Management. "Pending that appointment, the process has been stalled."

Last week, DEM officials and others working on Bay management made a presentation to the House Finance Committee in support of a budget amendment that would provide $1.3 million for monitoring.

Richard C. Ribb, head of the DEM's Narragansett Bay Estuary Program, was Carcieri's nominee to head the Bay coordination team. He said yesterday he never heard why his nomination was not confirmed by the Senate.

He said the 2003 fish kill brought a lot of attention to Bay issues and since then, some of the focus has been lost.

The governor is looking for a new nominee, said his spokesman, Jeff Neal. "When the Senate won't even review a nominee, it's hard to find qualified applicants. But we are looking."

Neal said the governor has proposed millions of dollars in bond issues to pay for continuing the cleanup and restoration of the Bay and the Bay's future remains a big issue for the governor.

Altieri had no idea he would swim into an historic pollution event when he began his research in the fall of 2000. He wanted to study the ecology of mussel beds.

Typically mussels attach themselves to rocks or pilings. But Altieri found vast "reefs" of mussels on the Bay floor, holding themselves up by attaching to each other with their golden byssal threads.

He found more than 250 acres of mussel reefs. The biggest covered about 64 acres at the north end of Prudence Island. He also found sizable reefs just south of Warwick Point, at the north end of Jamestown, just off Hog and Hope islands, and at other places around Prudence Island.

"It was pretty impressive," said Altieri. "They were living reefs."

He found the mussel reefs provided habitat for other animals, served as a food resource for other animals such as starfish, and played a critical role in filtering algae from the water.

Altieri stopped diving for a few weeks during the summer of 2001 because of an ear infection.

When he got back underwater in August, he said, "It was immediately obvious that something catastrophic had happened."

The mussels had fallen into piles of dead shells, many covered with white bacteria. The starfish were gone.

Altieri and Witman estimated that 80 percent of the mussels were dead. (Quahogs can tolerate much lower oxygen levels.)

When they returned to study the reefs in the fall of 2001 and a year later, they found one reef gone and seven others dramatically depleted.

Without the mussels filtering algae from the water, future algae blooms could be worse, in turn causing more problems for other marine life, Altieri said.

"This mussel story is a great indication of what can happen in the Bay," Altieri said. "The mussels were canaries in the coal mine. Hundreds of other estuaries have the exact same problem."

plord@projo.com/ (401) 277-8036