Harvesting and population status of Hexaplex trunculus (Gastropoda: Muricidae) in intertidal areas along the Gulf of Gabès (southern Tunisia)

Abstract

Although the banded murex (Hexaplex trunculus) is extensively exploited by hand harvesting in intertidal areas along the Gulf of Gabes (southern Tunisia), there is scarce information available on this fishing activity and on the population status of this muricid gastropod species. In this context, the present study aimed to characterise the harvesting activity and analyse the spatial distribution, abundance, biomass, population structure and mortality of H. trunculus. Sampling surveys were performed during March–August 2009 using quadrats (100 m2) in 721 sampling stations distributed along 157 transects perpendicular to the coastline. Overall, 6608 H. trunculus were collected with broad ranges in both shell length (13.6–78.5 mm) and total weight (0.2–63.8 g). GIS-produced maps were employed to illustrate the species spatial distribution, by extrapolating the estimated abundance, biomass and mortality to the total intertidal area surveyed in the Gulf of Gabes. This study provides baseline data on the local populations of H. trunculus, which constitutes valuable information for proposing conservation and management measures aiming ultimately to achieve the sustainable exploitation and long-term preservation of this coastal fishing resource from the Gulf of Gabes.