Abstract

The queen conch Aliger gigas (Linnaeus, 1758) is one of the most important fishery resources in the Caribbean. However, due to its biological characteristics and its high commercial demand, its populations have been overexploited. In Mexico, Chinchorro Bank is the only site where extraction of this resource is allowed through catch quotas, however, due to its drastic population decline and fishing pressure, in 2012 a temporary ban was established that ended in 2017. This study describes and compare the artisanal fishing of the queen conch for the last catch season in 2011 and the second catch season after the ban in 2018. A total of 14 fishing sites were identified, the fishermen preferred the sites located in the central zone of Chinchorro Bank. An increase in CPUE was observed between fishing seasons, probably due to the queen conch recovery for the five-year ban; however, the volume of queen conch that has been allowed for each fishing season was analysed and reflected a historical decrease for the last 30 years, which may be attributed to a decrease in population densities. Using shell length (SL) and lip thickness (LT) from a total of 4805 organisms a decrease in the mean size and size structure of queen conch is observed between fishing seasons, however, there was an increase in lip thickness due to population growth. The results indicate that the queen conch population dynamics at Chinchorro Bank has been affected due to the overexploitation of the resource. The fishermen have increased their catches of sublegal conchs and conchs that have not reached sexual maturity, due general decrease in SL. For the implemented ban to have the expected results, an increase in surveillance as well as an integrated management between stakeholders (fishers, consumers, authorities among others) is recommended.

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