INCREASED REGIONAL STABILITY OF BAY SCALLOPS IN SOUTHWEST FLORIDA.

Florida bay scallops persist in discrete populations along the Gulf Coast principally in near-shore, shallow-water seagrass beds in both bays and coastal waters.  Fish & Wildlife Research Institute (FWRI) biologists have assessed population trends since 1994 to assist in management of the recreational fishery. Commercial harvest has been prohibited since 1994.  Benchmarks include adult abundance (collapsed, < 0.01/m²; vulnerable, 0.01 - 0.1 / m²; stable, >0.1 / m²), adult distribution (sparse, < 25% of stations occupied; patchy 25-50%; dense, > 50%) and juvenile settlement (low, 0-0.1 settlers d^-1; moderate, 0.1-0.5 d^-1; high, > 0.5 d^-1).  

Collapsed local populations in the central and southwest Gulf Coast prompted a closure of the recreational fishery and attempts at active restoration.  Portions of the Nature Coast rebounded and were reopened in 2002, but the southwest estuaries did not recover.  In particular, average density in Pine Island from 1994 - 2003 was 0.003 / m² and scallops were found at only 34% of survey stations.    Community based restoration projects have been conducted by Mote Marine Laboratory, Sarasota Bay Watch, Florida Sea Grant, Sanibel-Captiva Conservation Foundation and commercial aquaculture facility Bay Shellfish in collaboration with FWRI since 2003.  

Average abundance in Pine Island Sound from 2004 - 2015 has increased to vulnerable (0.045 / m²) and dense (63 % of stations had scallops) with low but detectable settlement (0.016 d^-1).  The two other bay scallop populations in the region, Sarasota Bay (moderate, patchy) and Tampa Bay (moderate, dense), both have contributed to regional stability.  The modest recovery of SW FL scallop populations has occurred in spite of almost annual red tides in the region suggesting a renewed regional resiliency.  In addition, the southernmost portion of the nature coast population may serve as an important conduit between stable populations to the north and those described here.  Concerns include the relatively small area of available habitat, dense human population in surrounding counties, continued probability of major red tides, and highly managed water supply to the estuaries.  Until the three populations achieve stable and dense status, resilient to years of decline, with high settlement rates, all four should remain protected from harvest.