Abundance and Distribution of Phyllosoma in Southern Cuban Waters

Abstract

Introduction: The lobster industry is one of the biggest contributors to the Cuban economy. The Caribbean spiny lobster, Panulirus argus is the primary species harvested in Cuban waters and their numbers have decreased due to overfishing. Steps to replenish the industry and conserve the resource include implementing marine protected areas (MPAs), prohibiting female landings, and shortening the season. A large knowledge gap in the successful management of lobster is the variability and uncertainty of its early life history and recruitment. The larval (phyllosoma) stage can last 6-12 months in the plankton potentially providing a mechanism for the connectivity of lobster populations in the Caribbean region. It is important to understand these patterns to properly manage the lobster fishery. Objective: Assess the density and abundance of phyllosoma in Southern Cuban waters in relation to marine protected areas. Identify regions of interest using spatial analysis.

Methods: An oceanographic survey aboard the NOAA Ship Nancy Foster in southern Cuban waters took place 29 April to 19 May, 2015. A plankton net (1 x 2 m, 505 µ mesh) was towed from the surface to 50 m depth; samples were preserved in 95% ethanol. Phyllosoma were removed and densities at a subset of stations were calculated using the volume filtered (m3) at each tow. Phyllosoma abundance and densities were plotted using ArcGIS Pro. A Getis-Ord hot spot analysis was used to identify clusters of high densities. The hot spot analysis utilized z-scores to determine significance. Results: Phyllosoma abundance ranged from 0 to 2,523 Density and abundance showed variable results (Fig. 2), with high values found outside of MPAs (Table 1). One area of interest was identified using spatial analysis, with a significant (>99%) hot spot (Fig. 3).

Conclusions: The density and hot spot analysis showed uneven distribution of phyllosoma across the region, with a significant hot spot located 26 km west of the Isla de Juventud. The patchiness observed in the area did not coincide with MPAs indicating that complementary tools to preserve the fishery are needed. The next step is to create species-specific data and compare densities on a regional scale. However, due to limited access to this portion of the Caribbean, information on phyllosoma distribution is unknown but essential to improve our understanding of the early life history of lobster in the North Atlantic Ocean. Understanding connectivity is needed as human populations continue to grow, demanding increased harvesting of adult lobster in local and international markets.