SUMMARY UPDATE OF THE FLORIDA GULF COAST STONE CRAB FISHERY FROM 1962 TO 1993 by Stephania K. Bolden September 1994 National oceanic and Atmospheric Administration National Marine Fisheries Service Southeast Fishery Science Center 75 Virginia Beach Drive Miami, Florida Contribution: MIA-93/94-81 INTRODUCTION The Florida stone crab (Menippe mercenaria, IL._ adina and their hybrid) commercial f ishery has been steadily increasing in both landings and economic value. From 1990 through 1992, the stone crab consistently ranked as the third most valuable marine species landed on Florida's west coast being surpassed only by pink shrimp, and spiny lobster. The 1993 value of stone crab landed on the Florida Gulf coast equalled that of spiny lobster. The stone crab fishery continues to increase in landings and value. The annual stone crab ex-vessel value landed at Florida Gulf ports ranged from $7.9 million to $16.5 million from 1985 - 1993 and averaged $12.6 million. stone crabs are principally caught by commercial trap fishermen in the Gulf of Mexico waters off southwestern Florida. Until the 19601s, the Florida stone crab fishing area was mostly in the shallow waters of Monroe, Collier, Manatee and Pinellas Counties. In more recent years, the fishery area has expanded to include deeper waters for most Gulf of Mexico coastal counties from Monroe to Franklin. The original market for stone crab was consumers in the immediate fishing area. The current market is broader and is still mostly composed of seafood restaurants, local retail outlets, hotels and specialty food stores. There is no known foreign fishing for stone crabs within the US. The most-productive habitat and the largest producer of stone crab landings is the Everglades-Florida Bay area. This area is I characterized by a shoreline of mangrove swamp, extensive oyster reef development (Hoffneister, 1974), and broad turtle grass flats. The center of stone crab abundance is the Everglades National Park (GMFMC, 1986). The stone crab population was predicted to remain stable and productive (GMFMC, 1986), however the forecast was based on the Parks ecological stability. Because of the recent habitat degradation in Florida Bay due to lack of freshwater flow, the stability and productivity of the stone crab fishery may be threatened (McIvor et al., 1994). Larval stone crab (zoea) are extremely susceptible to salinity and temperature (Ong and Costlow, 1970), and in areas of shallow waters (i.e., Everglades National Park) fluctuating salinity and temperature may cause high larval mortality rates (Bert et al., 1978). Adult stone crab are much more hardy than the larvae and can tolerate most environmental extremes within their distribution range. The Everglades Forever Act requires the South Florida Water Management District to substantially increase water flows into Florida Bay. Meanwhile, interim projects like the Taylor Slough/Florida Bay Demonstration Project (Underwood, 1994) will alleviate the lack of natural freshwater flow. Freshwater influx into the stressed area will hopefully aid in preserving stone crab habitat and yield. Joint regulation between the Gulf of Mexico Fisheries Management Council and Florida Marine Fisheries Commission requires that only claws larger than 7 Cm (2.75 inches) in propodus length (claw length from the tip of the lower finger to the elbow) can be legally harvested and that live, declawed crabs be returned to the 2 water. Based on age/growth results of Lindberg and Marshall (1983), this minimum claw size regulation ensures at least one reproductive season before the crab enters the fishery. Although there is high mortality associated with declawed crabs (Davis et al., 1979), some survive and regenerate new claws. Mortality of declawed stone crabs was further discussed in prior reports (Bolden and Harper, 1992). Other management regulations intended to provide for stock conservation include: 1) prohibiting the harvest of egg bearing females, 2) moistening and shading captured crabs prior to claw removal in order to enhance survival of released crabs, and 3) closing the fishing season (May 16 to October 14) during the time of peak spawning activity. A moratorium on the issuance of Federal numbers and color codes for use in the Gulf of Mexico stone crab fishery is currently pending approval by the Secretary of Commerce. The moratorium (Amendment 5 to the Fishery Management Plan for the stone crab Fishery in the Gulf of Mexico) intends to discourage entry into the fishery based on economic speculation. During the moratorium (4- years) the State of Florida's Marine Fisheries Commission will develop alterative provisions to limit effort in the stone crab fishery. The Southeast Fisheries Science Center has periodically summarized commercial stone crab landings along Florida's Gulf Coast (Zuboy and Snell, 1980, 1982; Phares, 1982, 1985, Sutherland, 1988, 1989; Powers, 1990; Harper et al. , 1991; Bolden and Harper, 1992; Bolden, 1993). In addition, Restrepo (1990) produced a simulation model of f ishing on yield per recruit and egg production for the stone crab fishery. The estimates and precautions of the simulation model were addressed by Bolden and Harper (1992). The objective of the current review is to provide preliminary updated catch and effort data for the 1993-1994 stone crab season, verify 1992-1993 catch and effort data, compare recent landings by size categories and catch/trip, and depict historical trends in catch and effort. METHODS Commercial stone crab landings at ports on Florida's Gulf Coast extending from Monroe County in the south to Escambia County to the north were summarized. "Landings" refer to the pounds of stone crab claws that are sold by commercial fishermen to licensed wholesale dealers. Whole (live) weights of stone crabs can be obtained by multiplying claw weights by two. Although only claws are landed, most commercial statistics report stone crab landings as whole weights. Stone crabs caught by recreational fishermen or ones that are not sold to wholesale dealers are not reported and, therefore, not landings data. The General Canvas Landing System (GCLS) database maintained by NMFS and the Florida Marine Trip Ticket System database maintained by the Florida Department of Environmental Protection (FDEP, previously Florida Department of Natural Resources - FDNR) were analyzed to provide information contained within this report. Data prior to October 1985 were obtained from NMFS, GCLS database, 4 while those for the period of October 1985 to May 1994 wer;^ provided courtesy of FDEP. The October 1993 - May 1994 landings are preliminary and subject to change. Caution must be exercised when comparing landing trends before and after October 1985 due to differences between the two data collection programs. The differences between the two databases were discussed by Harper et al. (1991). Estimates of annual and monthly catch per trap were calculated by dividing landings by the estimated number of traps reported in the commercial fishery. The number of stone crab traps used in calculations is the estimated maximum number used at any time during the calendar year. The estimate is made by MMFS personnel each year and is based upon data obtained during an annual canvas of seafood dealers. Data deadlines are not compatible to allow comparison of the FDEP Saltwater Products License database and port sampler estimates to verify trap number. FDEP Marine Trip Ticket System data were also examined to determine monthly mean landings and number of traps hauled per trip. Mean landings/trip was calculated only for stone crab trips, (trips in which stone crabs constituted >=75% of the total landings); i.e. they do not include trips in which stone crabs were caught and landed incidentally by other fishing gears such as lobster traps, fish traps, or shrimp trawls. Mean number of trap hauls per trip was calculated by summing the number of trap hauls greater than 0 on trip tickets and dividing by the number of trips. Total trap fishing effort (number of trap hauls) was obtained by 5 :aultiplying the number of f ishing trips per month where stone crabs were the primary species caught, by the mean number of traps hauled per trip for that month. The stone crab fishing season extends from October 16 to May 14. Fishing season will be referred to by the year beginning the season (eg. 1980 season encompasses the period between October 16, 1980 through May 14, 1981). Stone crab landings for the months of June through September were presumed to be late reports. These data were included with annual totals for the previous season but were eliminated from graphic presentations of monthly landings, mean trap hauls per month, and catch-per-unit-ef fort (CPUE) because the actual landing date was not known. RESULTS AND DISCUSSION Stone crab landings at Florida Gulf coast ports for 1985 through 1993 are summarized by season, month, and claw size (Table 1). Landings for the 1993 fishing season are preliminary and subject to change. During the 1985-1993 period, about 47% of the landed claw weight was classified as large, 31% medium, 7% small, 4% jumbo and 12% ungraded by claw size. The commercial landings and ex-vessel value of stone crabs are presented in Figure 1. Ex-vessel price has steadily increased from $196,100 in 1962 to $16.5 million in 1993 with the exception of 1991 when the ex-vessel value plummeted to $12.4 million, a decrease of $3.6 million over one year. Market saturation during the first few months of the season was a cause suggested for the 6 1991 low ex-vesoel value as pounds landed remained relatively stable (Bolden, 1993). 1993 has the largest ex-vessel value, however 1992 was the bumper year in pounds of claws landed. Therefore, considering only pounds landed and ex-vessel value, I stone crab were more valuable in 1993 than in 1992.