Abstract

To better understand the habitat requirements of juvenile queen conch, we conducted visual surveys in a variety of habitats within East Harbour Lobster and Conch Reserve (EHLCR) from July 2000 to August 2001. Visual surveys were carried out using integrated line and beIt transects at randomly selected sites within the reserve every three to four months. All juvenile conch encountered were enumerated and categorized as small (< 150 mm), medium (150 - 200 mm), or large (> 200 mm), and the habitat type recorded to determine whether onto genetic shifts in habitat use were evident. The siphonallength of small juveniles was also measured to determine whether habitat use was size-dependent within this category. In addition, because small juveniles often remain in the substrate during the day, we conducted paired diurnal-nocturnal visual surveys in different habitats within the reserve to monitor their emergence. Our results indicate that small, medium, and large juveniles were most abundant in a unique, densety vegetated coral rubble habitat Algal plain habitat also contained arelatively high number of small juveniles, with the highest densities occurring within a small area (< 5 ha) believed to be a nursery ground. The majority of smaller juveniles (55-90 mm) observed during our surveys were found in this area, primarily at night. From these results we conclude that juvenile queen conch occupy a variety of habitats in EHLCR and that use of these different habitats is size-dependent. Our results also suggest that algal plain habitat may be important for small, post-settlement juveniles, although the generality of this finding remains to be tested.

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