Spiny Lobster Recruitment in South Florida: Quantitative Experiments and Management Implications

Understanding recruitment and identifying factors critical to that process are imperative if adult spiny lobster Panulirus argus stocks are to be conserved and properly managed. The goal of our research has been to obtain ecological infonnation linking inshore postlarval spiny lobster recruiunent to later life stages, lhereby providing the basic framework for assessing and predicting adult stock. Since 1983, we have investigaled various aspects of spiny lobster recruitment including: postlarval lime-lO-metamorphosis, postlarval/juvenile habitat selection and selection cues, posllarval/juvenile crypticity and susceptibility to predation, juvenile food preference and emigration, juvenile sociality, and lhe effect of habitat degradation (le., siltation) on postlarval/juvenile habitat selection and mortality. From this research we have established many of the basic biological and ecological determinants of the so-called ''missing stage" of the spiny lobster (i.e., settlement through first 3-4 months of benthic life). Currently, we are conducting quantitative field experiments evaluating: 1. The relalionship between surface collector catch (a standard measure of recruitment), postlarval settlement in algal clumps, and benthic juvenile abundance.and 2. The relative importance of settlement versus habitat carrying capacity in determining local lobster abundances. This research is ongoing, but preliminary results suggest that in Florida Bay: I. Settlement is patchy and highest near lhe keys. 2. Surface collectors are poor indicators of local settlement or recruiunent. 3. Suitable habitat may limit recruilment to the postalgal juvenile stage more than settlement