Efficacy of an established marine protected area at sustaining a queen conch Lobatus gigas population during three decades of monitoring

Marine ecology progress series

*, Heather Cronin¹  , Rachel Skubel²  , Carolyn A. Belak³  Andrew S. Kough⁴ 

[1] AIS Inc., 14 Barnabas Road, Marion, MA 02738, USA;Abess Center for Ecosystem Science and Policy, University of Miami, Miami, FL 33146, USA;California Department of Fish and Wildlife, Stockton, CA 95206, USA;Daniel P. Haerther Center for Conservation and Research, John G. Shedd Aquarium, Chicago, IL 60605, USA

关键词: Queen conch;    Marine protected area;    Benthic survey;    Senescence;    Size;    Age;   

DOI  :  10.3354/meps12163

学科分类：海洋学与技术

来源: Inter-Research

【 摘 要 】

Marine Protected Areas (MPAs) are designed to conserve and preserve the ecosystems and cultural resources of the ocean. In theory, protected populations flourish, replenish adjacent regions, and are self-sustaining. However, describing the efficacy of MPAs requires long-term monitoring. Queen conch Lobatus gigas are iconic Caribbean denizens with populations that have been decimated by overfishing and are slow to rebound due to density-dependent breeding. The Exuma Cays Land and Sea Park (ECLSP) is a well-enforced, no-take, old, and large MPA. Surveys in 1994, 2011, and 2016 were used to track changes in the abundance, size, and age structure of conch within the park. Statistical models suggested that abundances of adults in 50 km of repeated towed-observer surveys had declined by 71% in 2016 relative to 2011. Further, the remaining conch populations were associated with tidal channels, and these model results agreed with independent observations in 40 km of expanded survey area. Measurements of shell lip thickness, an estimator of relative age, showed an increase relative to 1994 with the greatest effect in 2016, indicating senescence. The ECLSP population appears to be slowly dying of old age, and an early life history process has been altered. Upstream populations have been heavily fished while habitats within the park remain productive, suggesting that low local retention and a lack of exogenous larval sources are driving the decline. A network of MPAs encompassing the entire life cycle and dispersal envelope of targeted organisms is needed for proper conch conservation. Surveys focused on tidal channels could locate candidate upstream populations of conch.

【 授权许可】

Unknown