| Queen Conch Hatchery Project |
| Staff Contact: Steve Canty |
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Conchs live in seagrass beds and sandy areas in close proximity to coral reefs. |
The Queen Conch, Strombus gigas, is the largest and longest lived of all marine gastropod snails in the Caribbean, growing to 30cm and living for up to 40 years. Their feeding behaviour, the consumption of, algae, detritus, and algal films makes them extremely important to the overall health of coral reef systems. More recently the harvesting of conch for international markets has placed increasing strain on conch populations and in 1992 CITES Convention of International Trade of Endangered Species placed it on their Appendix II list to increase control of trade. |
In 1994 the IUCN International Union for the Conservation of Nature recognised conch as commercially vulnerable to extinction. Honduras, which provided over 40% of the total conch exported from the Caribbean to the United States in 2001, has been particularly prone to export induced over harvesting. Serious concerns over the conch populations and the lack of fisheries management or enforcement lead to CITES placing a ban on imports from Honduras (and two other states in the Caribbean) in 2003 (Acosta, 2006) which lead to a government imposed ban on all commercial conch fishing in Honduras that remains in effect today. |
| Stock Recovery |
Even with a fishing ban, the ability for these populations to recover naturally would be a very long process.
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The main problem in the recovery of conch populations even when there is a ban on fishing is that Queen Conch must aggregate to reproduce. Males and females lock together to copulate, after which a fertilised egg sac is laid by the female in the sand. Therefore the density of individuals within an area is crucial to their reproductive success as they have to be able to find each other. Investigations by Stoner & Ray-Culp (2000) determined that a minimum of 56 sexually mature conch per hectare are required for mating to be triggered within the population, and a minimum of 200 sexually mature conch per hectare are estimated to be needed in order to have sufficient recruitment per year to form a stable population. |
Recent surveys including those conducted by UCME survey teams, suggest that Conch populations in the shallow near shore waters around the Bay Islands are very low with just a few individuals per hectare. |
| Our Approach |
Due to the ecological and economic importance of this species UCME has investigated ways to facilitate the rebuilding of the conch population by enhancing the survival rate of the initial stages of conch development. Naturally, only around 1 in 400,000 eggs survive to become a 2 cm length juvenile. The UCME conch development project aims to increase that survival success using a contained, small scale aquaculture facility that takes fertilised conch eggs from around Utila, nurtures them through hatching, then a pelagic larval stage and through settlement and growth into to a juvenile stage of approximately 2 cm. |
This project uses simple technology and a low cost set up. |
Working with the Cayan fishing community the aim of the project is to release over 1 million competent larvae and 75,000 juvenile conch per year into the shallow seagrass areas that are known conch nurseries around the cays and island of Utila. The project aims to increase the developmental survival rate to 20,000 competent juveniles per 400,000 eggs. Local members of the community are involved within the process of rearing the conch and releasing them to the nursery areas. This creates a focal point for education and awareness about resource stewardship which is an integral part of future sustainable use of the conch fishery. This project uses simple technology and a low cost set up and is forming the research and development phase for a larger aim of duplicating these facilities in similar communities across the north shore of Honduras to expand the rebuilding of conch populations at a local level. |
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The Queen Conch has been historically important within the Caribbean region as a traditional food product and important protein source for coastal communities. |
Key References
Acosta, C.A. (2006). Impending Trade Suspensions of Caribbean Queen Conch under CITES: A Case Study on Fisheries Impacts and Potential for Stock Recovery. Fisheries; 31, 601-606.
Stoner, A.W., and Ray-Culp, M. (2000). Evidence for Allee effect in an over-harvested marine gastropod: density-dependent mating and egg production. Marine Ecology Progress Series; 202, 297-302.
Tewfik, A., Guzmán, H.M., and Jácome, G. (1998). Assessment of the Queen Conch Strombus gigas (Gastropoda: Strombidae) population in Cayos Cochinos, Honduras. Rev. Biol. Trop; 46, 137-150. |
