Resumen

GOVENDER, Yogani. Long-term monitoring of crab Cardisoma guanhumi (Decapoda: Gecarcinidae) captures in Jobos Bay Estuary, Puerto Rico. Rev. biol. trop [online]. 2019, vol.67, n.4, pp.879-887. ISSN 0034-7744.  http://dx.doi.org/10.15517/rbt.v67i4.35124.

The densities of the land crab Cardisoma guanhumi has been declining due to overfishing, habitat degradation and loss, and continued capture in Natural Protected Areas (NPA). Numerous management strategies and regulations have been developed to monitor and reduce population declines. In Puerto Rico, an administrative order of 1999, regulates a closed season, prohibited the capture of crabs through the year from NPA’s and below a minimum size for capture (64 mm). The goal of this research was to monitor spatial-temporal dynamics of crab captures after the implementation of the administrative order. Crabs captured in the Jobos Bay Estuary (JBE) were studied over a 15-year period. The size (carapace width) (CW), sex, and color were documented for 1 531 crabs from 31 crab hunters. Significant temporal difference in crab size was observed (Kruskal Wallis = 46.82, P < 6.187e-9), the smallest crabs were captured in 2004 and the largest crabs were captured in 2013. Crab size varied by color (Kruskal Wallis = 86.54, P < 2.2e-16), larger crabs were blue, medium sized crabs were brown and smallest crabs were orange. Since color is related to development stage and market value, color can be used as an educational and enforcement tool. There was significant spatial difference in the size of crabs captured (Kruskal Wallis = 252.54, P < 2.2 e-16), smaller crabs were captured in smaller hunting areas. Only three percent of crabs captured from 2009 to 2018 were below the legal-size limit. Temperature had a weak significant positive relationship with crab size and in years when rainfall was lower smaller crabs were captured. Increases in crab size from 2004 to 2013 coincided with mangrove recovery and the current decrease of crab size coincides with droughts of 2015. Management plans in the Caribbean must include local actions to reduce hunting and climate variability impacts on crab habitat and food availability.

Palabras clave : spatial and temporal dynamics; climate variability; land crab fishery.

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