Seaweed diversity associated with a Brazilian tropical rhodolith bed

Abstract

This study describes the predominantly tropical, subtidal seaweed populations growing on rhodoliths between 4 and 18 m depth in the southern part of Espírito Santo State (Brazil). Qualitative and quantitative sampling revealed species-rich algal communities, comprising 167 species. Three species of rhodophytes represent new records for the Brazilian marine flora (Lithothamnion muelleri, Scinaia aborealis, and Mesophyllum engelhartii). Marked seasonal differences in fleshy algal species composition and abundance were related to seasonal instabilities caused by winter-storm disturbance over the rhodolith beds. In relation to depth, rhodolith density appears to be an important factor for the variation in the abundance of fleshy algae. The rhodolith community is composed of at least seven nongeniculate crustose coralline algal species. Rhodolith beds in southern Espírito Santo State, in an area of 150 km2, provide an important habitat for epibenthic communities, supporting 25% of the known macroalgal species richness along the Brazilian coast.