Matching spatial scales of variation in mussel recruitment and adult densities across southwestern Atlantic rocky shores

LORENA P. ARRIBAS; MARÍA BAGUR; JORGE L. GUTIÉRREZ; MARIA GABRIELA PALOMO

JOURNAL OF SEA RESEARCH

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2015 vol. 95 p. 16 - 21

1385-1101

The recruitment of aquatic invertebrate larvae often differs in space and time thus contributing to variation in theabundance of adults. In the present study, we examined spatial scales of variation in mussel (Brachidontes spp.)recruitment and adult abundance across rocky intertidal areas in the Southwestern Atlantic. Recruitment andadult densities were compared between two regions separated ca. 700 km from each other, two locations (10?20 km from each other) within each region, and two sites (100?500 m from each other) within each location.Variance components analysis indicates that most variation in mussel recruitment and adult densities occursat the scale of locations, irrespective of ifmussel recruitment is quantified onmussel bed samples or artificial substrates(plastic mesh collectors). Increased mussel recruitment and adult densities at this scale are associatedwith higher time-averaged chlorophyll a concentration andwave exposure,which can potentially affect the supplyof larvae to rocky shores by increasing their survival and delivery rates. There was close correspondence betweenthe spatial patterns of variation in cumulative recruitment on natural substrates during the study periodand the density of adults at its end. This suggests that differences in mussel abundance along Southwestern Atlanticrocky shores could be primarily determined by larval recruitment.