Postlarval settlement of the spiny lobster Panulirus argus along the Caribbean coast of Mexico: Patterns, influence of physical factors, and possible sources of origin

Abstract

We analyzed and compared 17 yr of monthly settlement indices of postlarvae of the Caribbean spiny lobster, Panulirus argus, at two locations on the Mexican Caribbean coast. Along this coast, the shelf is very narrow and the local circulation is driven by waves overtopping subtidal coral reef crests. Settlement occurred year‐round, but both locations showed annual rhythmicity, average seasonal maxima during the autumn, and similar interannual variation, reflecting the influence of mesoscale oceanographic processes on settlement. Significant correlations between settlement indices and a number of interrelated physical factors indicate that sea‐level variation is the main factor influencing settlement. There was further association between extreme settlement pulses and extreme weather events (tropical storms and hurricanes) during the late summer‐autumn. The autumn settlement peak indicates that large hurricane waves enhance the onshore transport of postlarvae that originated during the spring spawning peak. The geographic range of potential sources of larvae that settle along this coast during the periods of March‐April and September‐October, 5‐9 months after hatching (the estimated larval duration for P. argus), was investigated by stochastic simulations integrating passive trajectories backward in time using 6 yr of stable outputs from a well‐established numerical model for the entire Atlantic Ocean. Trajectories from the model indicate that the local population of P. argus depends to a large extent on larval supply from many potential source regions across and outside the Caribbean but that some larvae follow pathways that permit selfrecruitment.