A Predictive Habitat Model for the Reef Fish, Rainbow Parrotfish Scarus guacamaia

The rainbow parrotfish, Scarus guacamaia is a prominent teleost herbivore in the coastal waters of southeastern Florida whose life history is strongly linked to a dependence on both mangrove and coral reef habitats. Ecologically, the species serves a role in maintaining the health of coral reefs by controlling algal growth. Using NOAA Fisheries data from the Biscayne Bay and the Upper Florida Bay Mangrove Visual Census (1999-2007) and the Reef Visual Census (1979-2006) programs in combination, this study examined the different factors that affect the presence and absence of adult rainbow parrotfish and the ontogenetic shifts present in this species between juvenile and adult stages. Logistic regression was used to predict abundance and occurrence using environmental variables gathered contemporaneously during the studies of temperature, dissolved oxygen, salinity, average depth. A variable for the distance of each site from the nearest channel openings was later calculated using ArcGIS. Presence and absence were also measured against mangrove cover, bottom substrate type, and shoreline development based on available maps and literature. Salinity, average depth, and distance from channel openings were significant in predicting the occurrence of this species, while temperature and dissolved oxygen were not, showing the importance of specific habitat sites. Future research should examine larval dispersal patterns and utilize site fidelity research methods to provide a more accurate picture of occupancy. The health of this and other parrotfish species may be useful in determining the management breadth and priorities of coral reef communities across the greater Caribbean Sea region. Conservation efforts for this and similar parrotfish species, listed as vulnerable by the IUCN, need to be given greater consideration, along with including the ecologically important mangrove coverage within coral reef community conservation plans.