Habitat characteristics affecting fish assemblages on a Hawaiian coral reef
Alan M. Friedlandera, * and James D. Parrisha, b
a Hawaii Cooperative Fishery Research Unit, University of Hawaii, 2538 The Mall, Honolulu, Hawaii 96822, USA
b Biological Resources Division, U.S. Geological Survey, Honolulu, Hawaii 96822, USA
Received 6 December 1996;
revised 4 June 1997;
accepted 23 June 1997.
Available online 23 March 1998.
Abstract
Habitat characteristics of a reef were examined as potential influences on fish assemblage structure, using underwater visual census to estimate numbers and biomass of all fishes visible on 42 benthic transects and making quantitative measurements of 13 variables of the corresponding physical habitat and sessile biota. Fish assemblages in the diverse set of benthic habitats were grouped by detrended correspondence analysis, and associated with six major habitat types. Statistical differences were shown between a number of these habitat types for various ensemble variables of the fish assemblages. Overall, both for complete assemblages and for component major trophic and mobility guilds, these variables tended to have higher values where reef substratum was more structurally or topographically complex, and closer to reef edges. When study sites were separately divided into five depth strata, the deeper strata tended to have statistically higher values of ensemble variables for the fish assemblages. Patterns with depth varied among the various trophic and mobility guilds. Multiple linear regression models indicated that for the complete assemblages and for most trophic and mobility guilds, a large part of the variability for most ensemble variables was explained by measures of holes in the substratum, with important contributions from measured substratum rugosity and depth. A strong linear relationship found by regression of mean fish length on mean volume of holes in the reef surface emphasized the importance of shelter for fish assemblages. Results of this study may have practical applications in designing reserve areas as well as theoretical value in helping to explain the organization of reef fish assemblages.
sources: Coral reef fishes; Fish assemblage structure; Habitat complexity; Hawaii
Read More ...
0 comments:
Post a Comment