TIERRA VERDE — Organizers don't know what to expect when hundreds of snorkelers hit the water Saturday to look for scallops.
"We have had some really good years, and others … they have been hard to find," said Peter Clark, president of Tampa Bay Watch, sponsor of the Great Bay Scallop Search. "But one thing is for sure. The water quality in the bay is the best it's been since the 1950s."
Tampa Bay once had a thriving bay scallop fishery. That was before decades of habitat destruction and unregulated pollution nearly wiped out the population. But thanks to strict water quality regulations and the efforts of nonprofit groups such as Tampa Bay Watch, scallops have made a dramatic comeback.
"They are often likened to the canary in the coal mine," said Clark, who organized the first scallop search in 1993. "They are the first organism that will tell you something is wrong with an estuary."
In 1994, with scallop stocks declining, state officials shut down the commercial season everywhere and shut down the recreational season south of the Suwannee River. That included Crystal River and Homosassa, once among the state's best scallop spots.
But in 2001, state officials reopened the area between the Suwannee and the Pasco-Hernando county line because stocks had recovered. Scalloping, however, was still prohibited south of the Pasco-Hernando county line, which included Tampa Bay.
Researchers from USF and the Florida Fish and Wildlife Conservation Commission's research institute in St. Petersburg have had aggressive restocking, or "seeding," programs in place for more than a decade. The only way to find out if they were working was to send volunteer snorkelers into the bay to count scallops. That is where Tampa Bay Watch comes in.
"In 2009, we had a banner year with volunteers counting 674 scallops," Clark said. "But in 2013, they found only 51, and we aren't quite sure why."
Scallops need a mixture of saltwater and freshwater to survive. If rains are heavy — for example, when hurricanes strike — too much freshwater can flood the bay and wipe out a crop. If the water is too salty, they won't survive either.
Scallops do best in water with a salinity of 20 parts per thousand. The Gulf of Mexico is about 35 parts per thousand. If too much freshwater gets bottled up in the bay, they won't survive. That is why most scallops are found west of the Skyway.
"Things are really looking up for the bay," Clark said. "Between 1999 and 2008, we gained about 5,000 acres of seas grasses back. Then between 2008 and 2012 we gained another 5,000."
That is good news not only for scallop lovers, but anglers. The same habitat scallops need is ideal for snook, redfish and trout.
While the harvest of scallops is still prohibited in Tampa Bay, the waters off Homosassa, Crystal River and Steinhatchee are still open. The season runs through Sept. 24.