Hydrological, Diel and Lunar Factors Affecting Fishes on Artificial Reefs off Panama City, Florida

Ichthyofaunal surveys were conducted at two artificial reefs offshore Panama City, Florida from August 1979 to August 1980. Temperature, visibility and current speed of bottom waters, time of day, absolute time from noon (ATFN) and moon phase were tested via multiple regression to determine which factor(s) affected reef fish community structure and abundance of common taxa. Water temperature had the greatest influence on fish populations. Number of taxa (In S) and individuals (In N) of most common reef taxa was linearly related to water temperature. In N and abundance of several common reef taxa increased with increasing visibility. Moon phase was not an important factor in community index models; however, it did exert mixed influences on some common taxa's abundance. Current speed had a negative influence on In N, In S and number of taxa of fishes present in midwater censuses, and on two of the three common taxa's significant regression models. Time, expressed as time of census and ATFN, generally exerted negative influences on some common taxa's abundance. Except for evenness, all community indices exhibited highest values during summer–fall periods.