Community structure of coralline algae and its relationship with environment in Sanya reefs, China

Abstract

Coralline algae are an important functional group in coral reef ecosystems. Despite the importance of coralline algae, little is known about their abundance and community structure, especially within Sanya reefs. It was fundamental to study coralline algae species abundance and distribution, and evaluate the effects of environmental factors on the species composition and abundance in Sanya reefs. A total of 24 species in 10 genera were identified based on 11 sampling stations, with the family Corallinaceae being dominant within the study area. The 7 dominant species, which constituted 62.4% of the overall collection, were Amphiroa ephedraea (16.8%), Mesophyllum simulans (11.1%), Porolithon onkodes (9.8%), Neogoniolithon fosliei (7.5%), Mesophyllum mesomorphum (6.6%), Pneophyllum conicum (6.6%) and Hydrolithon boergesenii (4.0%). There was significant spatial variability in the species composition and abundance of coralline algae (ANOSIM: R = 0.356, P = 0.013). The correlation analysis between biotic and abiotic variables indicated that the turbidity had a negative effect and salinity had a positive correlation on the pattern of coralline algae assemblages (global ρ = 0.486, BIOENV analysis). The living cover of coralline algae was greater in deep water than in shallow water at the same sites. This suggests that physical disturbance, either natural or anthropogenic, is more important in regulating the coralline algae community structure in Sanya reefs.