Abstract

Since 1996, queen conch (Strombus gigas) density, distribution by benthic habitats, and size frequency distribution have been monitored in Parque Nacional del Este (PNE), southeastern Hispaniola. Delgado (1999) reported that queen conch are significantly more abundant in communities with sparse to modera te seagrass benthic coverage (<30%). He also reported a marked decline in overrall queen conch abundance from 1996 to 1997. As a recommendation from his findings, the government of the Dominican Republic declared Canal de Catuano as a permanent closeed area for conch fishing as of 1999 and additionally implement a closed season for the fishery between 1 July and 31 October for the country.\The purpose of this study was to continue ongoing studies of annual changes in queen conch population structure in a large marine lagoon within the park, using a stratified sampling design based upon benthic community type distribution. Annual surveys have focused on the density and location of juvenile aggregations, and the presence of adults as potential spawning stock by habitat available in the lagoon. The results obtained since 1996 to 2000 are part of a database that also contains information from historical conch populations (Torres et al. in prep) that once lived in the shallow waters of PNE. Shell length, width, and lip thickness (adults only) were collected along 50m x 5m transects located in different community types of the park, to determine if there are significant differences in conch densities during the study. These estimates also provide a baseline for evaluating future changes in population abundance and size structure relative to the recent closure of the park's lagoon. An annual evaluation of conch populations in PNE will serve as performance measures for PNE's managers.\Annual surveys conducted by Delgado (1999) in 1996 and 1997 showed significant declines (orders of magnitude) in the densities of both juvenile and adult concho Data collected during 2000 illustmte a continued decline injuvenile and adult densities, but less dramatically than in previous surveys. Conch density and size frequency distribution showed a significant difference among benthic community types inall years. There is no evidence of the effect of the closure of the lagoon from fishing or from the closed season. Continuation of annual surveys will help to evaluate the biological effects of the spatial and seasonal closures on queen conch in PNE, dependent, in part, on the ability of park managers to effectively implement the new regulations

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