Volume 58

Characterization of a Reproductively Active Queen Conch, Strombus gigas, Aggregation in the Nearshore Waters of South Florida

Bryan, D.R., B.K. Walker
Download PDF Open PDF in Browser

Other Information

Date: November, 2005

Pages: 490

Event: Proceedings of the Fifty Eighth Annual Gulf and Caribbean Fisheries Institute

City: San Andres

Country: Colombia


An aggregation of reproductively active queen conch, Strombus gigas, was observed August 2004 near Dania Beach, Florida, USA. S. gigas naturally occurs throughout the nearshore sand, seagrass and colonized pavements throughout south Florida in low abundance. However, a high concentration of individuals has been identified 40 m south of the Port Everglades inlet and 300 m east of the John U. Lloyd State Park beach in 5 m depth. Three surveys were conducted in December 2004, February 2005, and May 2005 to determine the density and distribution of the aggregation. The mean aggregation size during this six month period was 1915 individuals (SD = 707) associated with an average area of 3.01 ha (SD = 0.36). The mean shell length along four transects conducted during the May 2005 survey was 24.4 cm (SD = 1.68, n = 61). The distribution of the shell lengths within the aggregation is unimodal and suggests a distinct adult breeding aggregation that may have been the result of a single recruitment event. However, south of the adult aggregation along the nearshore habitat, numerous juvenile to young adult conch have been observed, signifying other recruitment pulses. During three of the four surveys, several conch were seen either mating or laying eggs and a few solitary egg masses were found. To our knowledge this is the first report of a reproductively active nearshore queen conch aggregation in southeast Florida as the nearshore conch population in the Florida Keys appears to be reproductively inactive. Currently, a permanent monitoring program is being established to determine if local beach renourishment will have any effect on the aggregation’s abundance, distribution, and fecundity.

PDF Preview