Spatio-temporal variation in surf zone fish communities at Ilha do Cardoso State Park, São Paulo, Brazil
Menegassi del Favero,Jana
In order to analyze the time-space variation of the fish fauna in the surf zone fish communities at Ilha do Cardoso State Park, São Paulo, Brazil, four consecutive hauls were done over a year on three beaches with different degrees of exposure, at low and high tide. To evaluate the influence of each abiotic variable over the fish community, a Canonical Correspondence Analysis was conducted. We identified 7.286 individuals belonging to 20 families and 47 species, most specimens collected were juveniles. At low tide, the highest diversity and richness values were calculated while the highest dominance was obtained at high tide. As for the number of species collected at the three beaches, stood out for the lower values the cooler months, between June and September. Abiotic variables explained 41.3% of the variability of biological data, where 11.4% corresponds to the spatial variation. Meanwhile the temporal variables accounted for 31.9% of the variation in abundance, where 26.3% of the variance explained nycthemeral variation. Additionally two groups were clearly observed between months with low and high temperature. However in this variable, the tidal variation, excluding the seasonal effect, explained 6.2%, while seasonality, excluding tide effect, explained 26.3%. Although the main measurable seasonal changes were related to temperature, water temperature showed a low percentage of explanation in the fish fauna variability (2.7%). Finally, it is emphasized that the seasonal changes in surf zone fish community primarily reflect patterns of recruitment determined by the reproductive activity and coastal circulation.