CHARLOTTE AMALIE, U.S. Virgin Islands — Fish populations in the underwater national monument around St. John and elsewhere in the U.S. Virgin Islands are so sparse that they may not be sustainable, marine biologists said.

U.S. National Oceanic and Atmospheric Administration (NOAA) researchers concluded two weeks of study last weekend at the Virgin Islands Coral Reef National Monument in St. John and the Buck Island Reef National Monument off St. Croix.

On Monday, they reported finding fish size and population to be about the same as the previous year: dangerously small.

"They're so low in the first place, its hard for them to go anywhere," said Mark Monaco, NOAA's chief scientist for the recent expedition. "There's not a lot of fish out there. You seldom see a fish larger than a clipboard."

The relatively low number of fish has been caused by overfishing and destruction of habitat, including coral reefs, Monaco said.

It was for that reason that President Bill Clinton expanded the Virgin Islands Coral Reef National Monument from 800 acres (320 hectares) to 1,900 acres (760 hectares) in 2001.

During the study, the NOAA team saw just one Nassau grouper, a fish once common to the area which scientists say was nearly fished out of existence in the 1970s and 1980s before receiving federally protection.

A candidate for the endangered species list, the Nassau grouper and the similar yellow fin grouper spawn during full winter moons at an area known as the Grammanik Bank, about 3 miles (about 5 kilometers) south of St. Thomas.

It is a relatively new spawning ground for the Nassau grouper, and scientists believe that their original spawning sites were so heavily overfished that they lost their memory of where they were and started following the yellow fin.

Rick Nemeth, director of the center for marine and environmental studies at the University of the Virgin Islands, said he wants officials to close the Grammanik Bank to fishing during grouping spawning season.

Nemeth has petitioned the Caribbean Fisheries Management Council, which regulates fisheries in this U.S. territory and Puerto Rico. But the group has not agreed to close it during the season, which runs from January through March.

Many fishers oppose any measure that limits the areas they can fish.

"Every time the fishermen find an area where the fish come to spawn, the government wants to close it down indefinitely," said fisher Neville Smith, who has fished in the U.S. Virgin Islands for more than 30 years.