Great Bay Scallop Search

scallop in grassThe Great Bay Scallop Search is a resource- monitoring program where volunteers snorkel along set transect lines in lower Tampa Bay to count scallops and document the population trend. The Great Bay Scallop Search has been conducted since 1993, with coordinating support provided by the Tampa Bay National Estuary Program.

The Great Bay Scallop Search is Tampa Bay Watch's most popular volunteer event each year. Not only does it give us the opportunity to bring attention to the bay's valuable resources, but it also promotes hands-on volunteerism and education to families and residents of the estuary. Many first time as well as "seasoned" scallop searchers comment on the exciting bay wildlife they see under the water during the event. Even if a search team does not find their elusive scallop prey, fun is always had by all!

NOTE: There is a closed harvest on scallops south of the Suwanee River and then only during the scheduled season. In order for scallop restoration efforts to be successful and to allow the population to increase to a point where harvesting may once again be allowed in Tampa Bay, illegal takings of scallops must be thwarted and reported to the proper authorities.

Video credit: Marcia Biggs, from the 2010 Great Bay Scallop Search

To play the video, be sure you have the Windows Media Player plug-in installed, then click the Play button.

 

Some Fast Facts About Bay Scallops (provided by the Tampa Bay Estuary Program):

  • Scientific name: Argopecten irradians
  • Size: About 2 inches
  • Distribution: Throughout Florida's west coast and as far north as West Palm Beach on the east coast
  • Habitat: Sea grass beds and shallow waters of estuaries
  • Although clams may live 40 years, the life span of a bay scallop is a fleeting 12-18 months.
  • An adult bay scallop can pump as much as 14.7 liters of water per hour by funneling water across open pathways on its gill covers. One of these pathways pumps in water containing food and oxygen, while the second expels the "cleansed" water along with waste products. Because scallops are extremely sensitive to pollution, they serve as useful "underwater canaries" to signal changes in water quality.
  • Scallops are a favored food of stone crabs, who have no trouble crushing the scallop's armored shell with their powerful claws. Researchers frequently find the outside of stone crab burrows littered with broken scallop shells.
  • Bay scallops develop male and female sex organs, producing both sperm and eggs. Of the 12-million or so eggs a single scallop releases, only one may survive to adulthood.
  • Tiny blue eyes along the outer rim of the shell detect movement and serve as an early warning system for scallops.
  • The delicious scallop meat so prized by seafood lovers is actually the scallop's adductor muscle, which it uses to close its shell.
  • Bay scallops disappeared from Tampa Bay in the 1960s when the bay was badly polluted. Since implementation of the Clean Water Act (1970), water quality conditions have gradually improved in the bay, and scallops are making a tentative comeback to our bay waters. Stocking efforts by the Florida Marine Research Institute are underway to help boost scallop recovery.
The bay scallop, or Argopecten irradians has virtually disappeared from Tampa Bay.  The scallop population has declined so dramatically that that it is illegal to harvest them in Tampa Bay.  Since scallops are extremely vulnerable to changes in water quality, there are a number of reasons for the dwindling numbers of Argopecten irradians.  Polluted bay water, red tide, and high rainfall events such as hurricanes are contributors to the decline of the scallop population. 

The Great Bay Scallop Search is an opportunity for citizens to assist in a resource monitoring program for the bay scallop.  Tampa Bay Watch and the Tampa Bay Estuary Program partner up each year for this popular event, held in late summer.  Volunteer boaters and snorkelers scour the seagrass beds in Boca Ciega and Middle Tampa Bays, searching for live scallops hidden among the blades of seagrass.  Volunteer participants in the Great Bay Scallop Search provide valuable data to Florida’s Fish and Wildlife Research Institute’s scientists who are working on restoring the scallop population in Tampa Bay. 

The Great Bay Scallop Search gives community volunteers an opportunity to learn about the bay’s valuable resources.  Many first-time as well as long-time scallop searchers comments on the exciting marine life they discover.  Even if a search team does not find a scallop, everyone has fun!  Once the boaters and snorkelers come ashore, Crabby Bills rewards the volunteers with a wonderful lunch. 

Here are some of the Great Bay Scallop Search results:

Year - # of live scallops:

1996 - 75
1997 - 79 
1998 - 27 
1999 - 21
2000 - 18 
2004 - 12 
2005 - 1 
2006 - 17.5  
2007 - 555 
2008 - 624
2009 - 674 (a banner year!)
2010 - 32
 
Searches were not held in 2001-2003 to allow water quality to improve.
  
An interesting feature of the scallop is its ability to filter water.  The bay scallop is a member of the shellfish family know as bivalves (for its two halves, or shells), and grows to about 2 inches in size.  The scallop feeds continuously through its open valves by filtering small particles of algae and organic matter in the water.  Scallops also breathe with their valves open and then close them when predators approach or if the water is too silty.   Silt, or particles of sediment can clog and ultimately harm the delicate gills of the scallop.  Many tiny, blue eyes along the outer rim of the shell detect movement near the animal and function as a warning system.  Scallops can swim backwards by clapping its valves and expelling water rapidly. 

For more information on this event, contact Kevin Misiewicz. Register as a volunteer to be notified of the upcoming Scallop Search events!