Habitat Characteristics as determinants of shelf edge fish communities, with emphasis on Scarid populations, off La Parguera, PR

Shelf edge reefs provide valuable habitat to a wide variety of marine organisms. Yet, because of their depth and highly sloping bottom these areas are not understood with respect to fish habitat relationships and even the way these environments can be characterized and mapped. In order to investigate the relationship between habitat complexity and fish utilization, this study has concentrated on the factors affecting Scaridae abundance at the shelf edge off of La Parguera, Puerto Rico. For remotely sensed data sets as well as in situ measurements, rugosity was classified using new techniques, developed for this study, that minimize bias associated with the slope of the substratum. An empirical orthogonal function analysis showed that parrotfish abundance on the shelf was associated primarily with structural variables. The results obtained from this study provide a novel approach to data interpretation that can be used in determining critical habitat to sensitive fish species.