Mass Migration of Juvenile Queen Conch (Strombus gigas) in the Bahamas

We summarize the available information for a mass migration of juvenile queen conch in the Bahamas. The migration was observed from April through June, 1987 over a large seagrass meadow and adjacent sand-algal plain at 1-5 m depths. Component aggregations ranged from 40-190 m in length and 1-6 m in width, with a maximum density of 319 conch/m2. Migrants averaged 101 mm in shell length, which ranged from 67-145 mm, and were of a similar size as non-migrants in the area The migration was directional towards ebb tidal flow and moved approximately 250 m, at rates of 2.7 - 4.8 m/d, from April until its dissociation in June. Given the characteristics of the migrants and aggregations, we conclude that a key function of the mass migration was as a dispersal mechanism for asynchronously emerged l+ year class of juvenile queen conch; other potential functions include reduction of predation-induced mortality and efficient utilization of food resources