Modeling the spatial distribution of commercially important reef fish on the west Florida shelf

This study estimated the spatial autocorrelation between individual population members from five reef fish species on the West Florida Shelf:  gag grouper (Mycteroperca microlepis), mutton snapper (Lutjanus analis ), red grouper (Epinephelus morio), red snapper (Lutjanus campechanus), and vermilion snapper (Rhomboplites aurorubens).  Video observations of reef fish presence, absence, and relative abundance were made by the Southeast Area Monitoring and Assessment Program (SEAMAP) using stratified random sampling from various blocks on reef and hard-bottom habitat in the Gulf of Mexico.  The spherical variogram model used was found to be highly sensitive to initial starting values when fit using non-linear least squares, and a sensitivity analysis was performed to obtain biologically reasonable parameter bounds.  Final model fits found that gag grouper, mutton snapper, and red grouper were spatially autocorrelated on reef or hard-bottom habitats at short ranges of between 0.87 and 0.95 kilometers, while red and vermilion snapper were found to be randomly distributed on reef or hard-bottom habitats.  The lack of observable spatial autocorrelation for red and vermilion snapper may be related to the fact that their dietary and habitat preferences were not well sampled by the SEAMAP methodology in comparison to the other species.