A groundwater-fed coastal inlet as habitat for the Caribbean queen conch Lobatus gigas-an acoustic telemetry and space use analysis

摘要

The queen conch Lobatus (Strombus) gigas, a marine snail, is among the most important fisheries resources of the Caribbean region. To provide effective protection in marine reserves, a good understanding of its habitat usage is essential. Queen conches commonly inhabit marine habitats. In this study, its activity space in a marginal estuarine-like habitat, the groundwater-fed inlet of Xel-Ha (Mexico) was determined using high-resolution acoustic telemetry (VEMCO Positioning System). Thirty-eight animals with syphonal lengths ranging from 80 to 200 mm were tagged, 1 of them with an accelerometer tag. Their trajectories were recorded for 20 mo at 5 m resolution in a closely spaced array of 12 receivers. Space-time kernel home ranges ranged from 1000 to 18 500 m(2) with an ontogenetically increasing trend. Juveniles, subadults and most adults displayed continuous, non-patchy home ranges consistent with the typical intensive feeding activity by this fast-growing gastropod. In some adults, Levy flight-like fragmentation of home ranges was observed that may be related to feeding range expansion or other ecological drivers such as the breeding cycle. The observed small home ranges indicate that the space use of queen conch in this estuarine-like habitat is not conditioned by food availability, and despite environmental stress due to daily low-oxygen conditions, space use is comparable to that observed in more typical marine habitats. In a marine reserve context, the groundwater-fed inlet provides adequate protection of this inshore queen conch population. Such marginal habitats may play an increasingly important role in conservation management as pressure on populations increase.