Diversity, structure and functioning of rocky coastal ecosystems in northern Chile Diversidad, estructura y funcionamiento de ecosistemas costeros rocosos del norte de Chile
Vasquez, J.A.; Camus, P.A.; Ojeda, P.F.
Revista Chilena de Historia Natural. Diciembre; 714: 479-499
1998
Document Number: 529552
This study, among others of the Fondecyt Sectorial Program directed toward the study of biodiversity of Antofagasta, was carried out in three rocky areas on the exposed coast of northern Chile selected for their representation of varying upwelling regimes: (a) Caleta Constitucion (Mejillones-Antofagasta Peninsula) located in a stable focus of coastal upwelling; (b) Carrizal Bajo (Huasco), a reference zone without permanent coastal upwelling; and (c) San Lorenzo (Punta Lengua de Vaca), a reference zone of contrast, on a focus of stable upwelling. The general objectives of our study were: (1) characterize the taxonomic composition and community structure, as a function of categories or trophic levels in subtidal and intertidal habitats; (2) characterize the spatio-temporal dynamics of the diversity and abundance of species in the communities studied, relating these to variations in productivity and sea surface temperature (obtained by remote sensing); and (3) evaluate the effects of upwelling on community attributes in relation to similar comparisons between areas with and without upwelling. Our results show that the frequency of upwelling was not a determining factor in the diversity of the rocky littoral communities which were studied. Although the species richness of the subtidal benthos and ichthyofauna is greater in Caleta Constitucion (permanent upwelling) than in Carrizal Bajo (seasonal upwelling), these values were lowest for San Lorenzo (permanent upwelling). In contrast, the species richness of intertidal habitats did not show evident differences among the communities studied. There was no relationship evident between the diversity of primary producer and benthic herbivores with the frequency of coastal enrichment. However, patterns of abundance and diversity of some producers groups (eg. Chlorophytes) showed that the importance of coastal upwelling cannot be discarded in specific cases, although the changes may not be observed at the community level.