Keywords
fishing sustainability
overfishing
population simulation
population viability
sexual maturity
fishery management
fishing sustainability
overfishing
population simulation
population viability
sexual maturity
How to Cite
Abstract
The queen conch Strombus gigas represents one of the most important fishery resources of the Caribbean but heavy fishing pressure has led to the depletion of stocks throughout the region, causing the inclusion of this species into CITES Appendix II and IUCN’s Red-List. In Mexico, the queen conch is managed through a minimum fishing size of 200mm shell length and a fishing quota which usually represents 50% of the adult biomass. The objectives of this study were to determine the intrinsic population growth rate of the queen conch population of Xel-Ha, Quintana Roo, Mexico, and to assess the effects of a regulated fishing impact, simulating the extraction of 50% adult biomass on the population density. We used three different minimum size criteria to demonstrate the effects of minimum catch size on the population density and discuss biological implications. Demographic data was obtained through capture-mark-recapture sampling, collecting all animals encountered during three hours, by three divers, at four different sampling sites of the Xel-Ha inlet. The conch population was sampled each month between 2005 and 2006, and bimonthly between 2006 and 2011, tagging a total of 8 292 animals. Shell length and lip thickness were determined for each individual. The average shell length for conch with formed lip in Xel-Ha was 209.39±14.18mm and the median 210mm. Half of the sampled conch with lip ranged between 200mm and 219mm shell length. Assuming that the presence of the lip is an indicator for sexual maturity, it can be concluded that many animals may form their lip at greater shell lengths than 200mm and ought to be considered immature. Estimation of relative adult abundance and densities varied greatly depending on the criteria employed for adult classification. When using a minimum fishing size of 200mm shell length, between 26.2% and up to 54.8% of the population qualified as adults, which represented a simulated fishing impact of almost one third of the population. When conch extraction was simulated using a classification criteria based on lip thickness, it had a much smaller impact on the population density. We concluded that the best management strategy for S. gigas is a minimum fishing size based on a lip thickness, since it has lower impact on the population density, and given that selective fishing pressure based on size may lead to the appearance of small adult individuals with reduced fecundity. Furthermore, based on the reproductive biology and the results of the simulated fishing, we suggest a minimum lip thickness of ≥15mm, which ensures the protection of reproductive stages, reduces the risk of overfishing, leading to non-viable density reduction.
References
Abott, R. T. (1974). American seashells; the marine molluska of the atlantic and pacific coasts of north america. New York: Van Nostrand Reinhold Company.
Acosta, A. C. (2006). Impending trade suspensions of Caribbean queen conch under cites: A case study on fishery impacts and potential for stock recovery. Fisheries, 31, 601-606.
Alcolado, P. M. (1976). Crecimiento, variaciones morfológicas de la concha y algunos datos biológicos del cobo Strombus gigas L. (Mollusca, Mesogastropoda). Academia de Ciencias de Cuba Serie de Oceanología, 34, 1-36.
Aldana-Aranda, D., Sánchez-Crespo, M., Reynaga Alvarez, P., Patiño-Suárez, V., George-Zamora, A., & Baqueiro-Cárdenas, E. R. (2005). Crecimiento y temporada reproductiva del caracol rosa Strombus gigas en el parque Xel-Há, México. Proceedings of the Gulf and Caribbean Fishery Institute, 56, 741-754.
Aldana-Aranda, D. & Frenkiel, L. (2007). Lip thickness of Strombus gigas, Mollusca Gastropoda versus maturity: a management measure. Proceedings of the Gulf and Caribbean Fishery Institute, 58, 431-442.
Appeldoorn, R. S. (1988). Age determination, growth, mortality and age of first reproduction in adult queen conch, Strombus gigas L., off Puerto Rico. Fishery Research, 6, 363-378.
Appeldoorn, R. S. (1994). Spatial variability in the morphology of queen conch and its implication for management regulations. In R. S. Appeldoorn & B. Rodriguez (Eds.), Queen conch biology, fisheries and management (pp. 145-158). Caracas: Fundación Científica Los Roques.
Ávila-Poveda, O. H. & Baqueiro-Cárdenas, E. R. (2006). Size at sexual maturity in the queen conch Strombus gigas from Colombia. Boletín de Investigación Marina y Costera, 35, 223-233.
Baqueiro-Cárdenas, E. R. & Aldana-Aranda, D. (2010). Histories of success for the conservation of populations of queen conch (Strombus gigas). Proceedings of the Gulf and Caribbean Fishery Institute, 62, 306-312.
Basurto, M., Espinosa, J. M., Cob, E., & Escobedo, G. (2009). Dictámen Técnico: Estimación de biomasa explotable de Strombus gigas en los bancos abiertos a la pesca en Quintana Roo, México: Banco Chinchorro y Banco de Cozumel. Temporada de Captura 2009-2010.
Berg, C. J. & Glazer, R. A. (1991). Current research on queen conch (Strombus gigas) in Florida waters. Proceedings of the Gulf and Caribbean Fishery Institute, 40, 303-306.
Birch, L. C. (1948). The intrinsic rate of natural increase of an insect population. Journal of Animal Ecology, 17, 15-26.
Brownell, W. N. & Stevely, J. M. (1981). The biology, fisheries and management of the queen conch Strombus gigas. Marine Fishery Review, US Department of Commerce, 43(7), 1-12.
Cala, Y. R., Jesús de Navarrete, A., Ocaña, F. A., & Oliva Rivera, J. (2013). Densidad, estructura de tallas y actividad reproductive del caracol rosado Eustrombus gigas (Mesogastropoda: Strombidae) en Banco Chinchorro, México. Revista de Biología Tropical, 61(4), 1657-1669.
Chakalall, B. & Cochrane, K. L. (1996). The queen conch fisheries in the Caribbean – An approach to responsible fishery management. In J. M. Posada & G. Garcia-Moliner (Eds.), Proceedings of the First International Queen conch Conference, San Juan, Puerto Rico, 29-31 July 1996 (pp. 60-76). San Juan: Caribbean Fisheries Management Council.
Chávez-Villegas, J. F. (2011). Abundancia espacio-temporal de larvas de Strombus gigas (Linnaeus, 1758) en el sistema arrecifal mesoamericano (Master's thesis). CINVESTAV-IPN, Mérida.
Clerveaux, W., Danylchuk, A. J., & Clerveaux, V. (2005). Variation in queen conch shell morphology: management implications in the Turks and Caicos Islands, BWI. Procedings of the Gulf Caribean Fishery Institute, 56, 715-724.
Davis, M., Mitchell, B. A., & Brown, J. L. (1984). Breeding behavior of the queen conch S. gigas held in natural and enclosed habitat. Journal of Shellfish Research, 4(1), 17-21.
De Jesús-Navarrete, A., González, E., Oliva, J., Pelayo, A., & Medina, G. (1992). Advances over some ecological aspects of queen conch Strombus gigas, L. in the southern Quintana Roo, Mexico. Proceedings of the Gulf and Caribbean Fishery Institute, 45, 18-24.
De Jesús-Navarrete, A. & Valencia-Beltrán, V. (2003). Abundance of Strombus gigas zero-year class juveniles at Banco Chinchorro Biosphere Reserve, Quintana Roo, Mexico. Bulletin of Marine Science, 73, 232-240.
De Jesús-Navarrete, A., & Valencia-Hernández, A. (2013). Declining densities and reproductive activities of the queen conch Strombus gigas (Mesogastropoda: Strombidae) in Banco Chinchorro, eastern Caribbean, Mexico. Journal of Tropical Biology, 61(4), 1671-1679.
Eikeset, A. M., Richter, A. Dunlop, E. S., Dieckmann, U., & Stenseth, N. C. (2013). Economic repercussions of fisheries-induced evolution. PNAS, 110(30), 12259-12264.
Friedlander, A., Appeldoorn, R. S., & Beets, J. (1994). Spatial and temporal variations in stock abundance of queen conch, Strombus gigas, in the U.S. Virgin Islands. In R. S. Appeldoorn & B. Rodriguez (Eds.), Queen conch biology, fisheries and management (pp. 51-60). Caracas: Fundación Científica Los Roques.
Gotelli, N. J. (1959). A primer of ecological statistics. Sunderland, Massachusetts: Sinauer Associates, Inc.
Krebs, C. J. (1999). Ecological Methodology, 2nd ed. Vancouver: Addison-Wesley Educational Publishers, Inc.
Marshall, C. T., Needle, C. L., Yaragina, N. A., Ajiad, A. M., & Gusev, E. (2004) Deriving condition indices from standard fisheries databases and evaluating their sensitivity to variation in stored energy reserves. Canadian Journal of Fishery and Aquatic Science, 61(10), 1900-1917.
Peel, J. R. (2012). Dinámica poblacional y utilización ontogénica del hábitat por el Caracol rosa (Strombus gigas), en el parque Xel-Há, Quintana Roo, México (Master's thesis). Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Mérida.
Peel, J. R. & Aldana-Aranda, D. (2012). Size related distribution and mobility of the queen conch Strombus gigas in the Xel-Há Park, Mexican Caribbean. Book of Abstracts of the Proceedings of the Gulf and Caribbean Fishery Institute, 65, 154.
Pérez-Pérez, M. & Aldana-Aranda, D. (1998). Análisis preliminar de la densidad del caracol rosado (Strombus gigas) en el arrecife Alacranes Yucatán, México. Proceedings of the Gulf and Caribbean Fishery Institute, 50, 49-65.
Pérez-Pérez, M. & Aldana-Aranda, D. (2000). Distribución, abundancia, densidad y morfometría de Strombus gigas (Mesogastropoda: Strombidae) en el Arrecife Alacranes Yucatán, México. Revista de Biología Tropical, 48, 51-57.
Pérez-Pérez, M. & Aldana-Aranda, D. (2003). Actividad de Strombus gigas (Mesogastropoda: Strombidae) en diferentes hábitats del arrecife Alacranes, Yucatán. Revista de Biología Tropical, 51, 119-126.
Phillips, M., Bissada-Gooding, C., & Oxenford, H. A. (2010). Preliminary investigation of the movements, density, and growth of juvenile queen conch in a nursery area in Barbados. Proceedings of the Gulf and Caribbean Fishery Institute, 63, 427-434.
Randall, J. E. (1964). Contribution to the biology of the queen conch Strombus gigas. Bulletin of Marine Science, 14, 246-295.
Ray, M. & Stoner, A. W. (1994). Experimental analysis of growth and survivorship in a marine gastropod aggregation: balancing growth with safety in numbers. Marine Ecology Progress Serie, 105, 47-59.
Ríos-Lara, G. V., Cervera-Cervera, K., Espinoza-Méndez, J. C., Pérez-Pérez, M., Zetina-Moguel, C., & Chable Ek, F. (1998). Estimación de las densidades de langosta espinosa (Panulirus argus) y caracol rosa (Strombus gigas) en el área central del Arrecife Alacranes, Yucatán, México. Proceedings of the Gulf and Caribbean Fishery Institute, 50, 104-127.
Sánchez-Crespo, M. & Aldana-Aranda, D. (2012). Caracterización del periodo reproductivo y desove del caracol rosa Strombus gigas en el parque Xel-Há, Quintana Roo, México. Book of Abstracts of the Proceedings of the Gulf and Caribbean Fishery Institute, 65, 154.
Stoner, A. W. (1989). Density-dependent growth and grazing effects of juvenile queen conch Strombus gigas L. in a tropical seagrass meadow. Journal of Experimental Marine Biology and Ecology, 130(2), 119-133.
Stoner, A. W. (1997). The status of queen conch Strombus gigas research in the Caribbean. Marine Fishery Research, 59(3), 14-22.
Stoner, A. W., Glazer, R. A., & Barile, P. J. (1996). Larval supply to queen conch nurseries: Relationships with recruitment process and population size in Florida and the Bahamas. Journal of Shellfish Research, 15(2), 407-420.
Stoner, A. W. & Ray-Culp, M. (2000). Evidence for Allee effects in an over-harvested marine gastropod: density-dependent mating and egg production. Marine Ecology Progress Series, 202, 297-302.
Stoner, A. W., Mueller, K. W., Brown-Peterson, N. J., Davis, M. H., & Booker, C. J. (2012a). Maturation and age in queen conch (Strombus gigas): Urgent need for changes in harvest criteria. Fishery Research, 131-133, 76-84.
Stoner, A. W., Davis, M. H., & Brooker, C. J. (2012b). Negative consequences of Allee effect are compounded by fishing pressure: comparison of queen conch reproduction in fishing grounds and marine protected area. Bulletin of Marine Science, 88(1), 89-104.
Stoner, A.W. & Ray, M. (1993). Aggregation dynamics in juvenile queen conch (Strombus gigas): population structure, mortality, growth and migration. Marine Biology, 116, 571-582.
Stoner, A. W., & Sandt, V. J. (1992). Population structure, seasonal movements and feeding of queen conch, Strombus gigas, in deep water habitats of the Bahamas. Bulletin of Marine Science, 51, 287-300.
Stoner, A. W. & Schwarte, K. C. (1994). Queen conch, Strombus gigas, reproductive stocks in the central Bahamas: distribution and probable sources. Fishery Bulletin, 92, 171-179.
Thiele, S. (2001). Queen conch fisheries and their management in the Caribbean. (Technical Report to the CITES Secretariat in Completion of Contract A 2000/01). Traffic Europe.
Comments
This work is licensed under a Creative Commons Attribution 4.0 International License.
Copyright (c) 2014 Revista de Biología Tropical