1. Species composition and sampling methodology
Fish assemblages associated with our artificial reefs varied
significantly with sampling technique (visual censuses× gillnets)
and seasonal period (dry × rainy). Further, sampling technique
contributed more than season to data variability in fish surveys.
Many authors have argued on the importance of sampling program to
characterize the fish assemblages associated with artificial reefs
(Bohnsack and Sutherland, 1985; Bortone and Kimmel, 1991; Seaman,
2000). Here, comparisons with previous studies on artificial reefs
performed on the north coast of Rio de Janeiro provided an
opportunity to check the precision of our data.
Zalmon et al. (2002) recorded, through a 2-year gillnet monthly
samplings at concrete and tire reefs located ca. 5 km away from our
experiment, 45 fish species, of which 14 species were common in both
studies and 10 species were exclusive of our reefs. Taking into account
the differences between reef systems (materials, structural complexity
and size) and sampling effort (24 monthly samples of Zalmon et al.