Spatial synchrony in the recruitment of intertidal invertebrates along the coast of central Chile

Abstract

Recruitment is among the processes that most directly influence spatio-temporal pat- terns of abundance, productivity, and persistence in marine populations. Understanding the connec- tion between patterns of recruitment and environmental forcing has major implications for the con- servation and management of marine ecosystems. Theoretical and empirical studies have shown that dispersal and regional variability in environmental conditions may synchronize distant populations and generate patterns of spatial synchrony (i.e. decay in synchrony with distance). Here, we submit that recruitment synchrony patterns may be used to identify processes shaping the distribution of marine populations. We used artificial substrates to estimate patterns of spatial synchrony in recruit- ment for 15 intertidal invertebrates at 16 exposed rocky platforms spanning 120 km of the central coast of Chile. Clear and significant synchrony patterns were found for only 4 species: the barnacles Jehlius cirratus, Notochthamalus scabrosus, and Notobalanus flosculus, and the bivalve Perumytilus purpuratus, all of which occur at comparatively high abundance across the study region. The strength of synchrony decayed with distance, from positively correlated fluctuations for sites separated by 40 km apart. Patterns of spatial synchrony in recruitment resembled those of fluctuations in sea surface temperature, suggesting that mesoscale processes such as coastal upwelling may shape recruitment patterns by way of modulating larval dispersal. A lack of clear synchrony patterns in the remaining species could be ascribed to their low abundance, or, for those with potentially limited larval dispersal (e.g. direct development), it could indicate our lack of adequate spatio-temporal resolution to detect recruitment variability at small scales.