Nearshore fish assemblages along the central west coast of Florida

Fish assemblages and their relationship to oceanographic variables off the central west coast of Florida in the spring seasons from 1994 to 1997 are described. Samples were collected using a 19.8-m bottom trawl at 24 to 35 stations each year between 26° and 29° north latitudes in 6- to 27-m depths. Three general species assemblages were identified from cluster dendrograms: offshore (A), inshore (B), and northern inshore (C); however these assemblages had many species in common. The offshore assemblages were composed of reef and forage fish species that included sparids, haemulids, serranids, and lutjanids and of small coastal pelagics species, generally Decapterus punctatus and Sardinella aurita. The inshore assemblage was mostly composed of small coastal pelagics species such as S. aurita, Opisthonema oglinum, Harengula jaguana, Chloroscombrus chrysurus and forage fish such as Lagodon rhomboides, and Eucinostomus spp. Calamus arctifrons and Diplodus holbrooki characterized the northern inshore assemblage, although other forage species were also collected. Species group 1 (Aluterus schoepfi, Calamus proridens, Diplectrum formosum, D. punctatus, Equetus lanceolatus, Haemulon aurolineatum, Lactophrys quadricornis, and Synodus foetens) had the highest constancy for assemblage A and species group 2 (Caranx crysos, Eucinostomus spp., L. rhomboides, H. jaguana, O. oglinum, and Orthopristis chrysoptera) had the highest constancy for assemblage B. Low fidelity values occurred for all species groups over all fish assemblages except for species group 3. Species group 3, which included C. arctifrons and D. holbrooki, had high fidelity in the northern inshore assemblage. Ordination of oceanographic variables by principal component analysis (PCA) indicated that 80% of the variation between stations would be explained by the first two principal components with depth, salinity, and chl a having nearly equal loadings in the first principal component. Temperature had the greatest loading in the second principal component. A weighted Spearman's rank correlation between biotic and abiotic similarity matrices suggested that the environmental similarity matrix containing depth and salinity most closely matched the biotic matrix. However, the correlations between the biotic and abiotic matrices were low (