Is seagrass an important nursery habitat for the Caribbean spiny lobster, Panulirus argus, in Florida?

Caribbean spiny lobster (Panulirus argus) settle preferentially in macroalgal-covered hard-bottom habitat, but seagrass is more prevalent in Florida (United States) and the Caribbean, so even low settlement of lobsters within seagrass could contribute substantially to recruitment if post-settlement survival and growth were high. We tested the role of seagrass and hard-bottom habitats for P. argus recruitment in three ways. We first explored possible density-dependent regulation of early benthic juvenile lobster survival within cages deployed in seagrass and hard-bottom habitats. Second, we compared settlement and survival of P. argus in both habitats, by comparing the recovery of microwire-tagged early benthic juveniles from patches of seagrass and hard-bottom. Finally, we assessed the relative abundance of juvenile lobsters in each habitat by deploying artificial structures in seagrass sites and compared these data with data from similar deployments of artificial structures in hard-bottom habitat in other years. More early benthic juvenile lobsters were recovered from cages placed in hard-bottom than in seagrass, but mortality of the early benthic life stage was high in both habitats. In regional surveys, the mean number of lobsters recovered from artificial shelters deployed within seagrass was lower than in any year that we sampled hard-bottom, indicating that fewer lobsters reside naturally in seagrass, particularly large juveniles >40 mm carapace length. The greater abundance (and likely survival) of juvenile P argus that we observed in hard-bottom habitat as opposed to seagrass, combined with previous studies demonstrating that postlarval P. argus are attracted to, settle in, and metamorphose more quickly in red macroalgae, confirm that macroalgae-dominated hard-bottom habitat appears to be the preferred and more optimal nursery for Caribbean spiny lobster.