MUSSEL (MYTILUS-GALLOPROVINCIALIS LAMARCK) SETTLEMENT IN THE RIA-DE-VIGO (NW SPAIN) DURING A TIDAL CYCLE

The settlement of mussel was determined during a tidal cycle in an exp osed rocky shore in the Ria de Vigo (northwestern Spain) and 300 m awa y from it. In the exposed rocky shore, mussel settlement was recorded throughout the intertidal profile during the tidal cycle. Settlement w as more abundant in the lower than in the upper intertidal zone. The s ize of settled mussels varied from 0.250 to 11 mm. The largest mussels were found in the lower intertidal zone. Maximum densities were recor ded during the high tide, and the minimum were recorded during the low tide. Three hundred meters away from the mussel bed, settlement occur red during the complete tidal cycle. A light increase in the number of settled mussels during high tide was recorded. Settlement was more ab undant at 2- than at 5- and at 8-m depth. The size of settled mussels varied from 0.225 to 0.375 mm and was similar at all depths studied.