Influence of mussel rafts on spatial and seasonal abundance of crabs in the Ría de Arousa, North-West Spain

✍ Scribed by P. Romero; E. González-Gurriarán; E. Penas

• Publisher: Springer-Verlag
• Year: 1982
• Tongue: English
• Weight: 721 KB
• Volume: 72
• Category: Article
• ISSN: 0025-3162
• DOI: 10.1007/bf00396921

✦ Synopsis

The crab community in the Ria de Arousa, North-West Spain, was studied for 2yr (1974-1975; 1975-1976), firstly to detect any differences due to mussel (Mytilus edulis) raft aquaculture; secondly to study temporal changes in spatial distributions in beach, raft and non-raft areas throughout the ria. Portunid crabs dominated the fauna, the dominant species being Macropipus puber and M. depurator in the raft areas, M. depurator in non-raft subtidal areas, and M. arcuatus in beach stations. No substantial seasonal changes were observed in species composition throughout the ria. In general, the highest densities occurred in fall and winter. Raft stations showed the highest values of abundance, up to 0.47 individual per m 2, and 8.20 g wet wt m -2. The food resource provided by the rich epifauna associated with the mussel rafts, and changes in the sediment due to shell deposits could account for the high density values in raft areas. Raft areas (polygons) cover about 10% of the surface of the Ria de Arousa and, thus, the raft aquaculture of mussels significantly increases crab production.