| Popis: |
Seas and oceans are impacted by multiple human activities such as urban spills, maritime transport and tourism, among others. These human-generated pressures are directly impacting marine ecosystems, generating pollution, loss of habitat or introduction of exotic species. The objective of this work was to evaluate the environmental health of different beaches belonging to four coastal districts of the Province of Buenos Aires: Necochea, General Alvarado, General Pueyrredon and Mar Chiquita. The study was approached from the variability in the community structure (richness, evenness and diversity), as well as characterizing this structure from the analysis of functional traits and functional diversity indexes (functional features and indexes of functional diversity: functional richness, functional evenness, functional divergence, functional dispersion, functional specialization and quadratic entropy) and environmental quality indexes (AMBI and M-AMBI) in response to different pollution scenarios due to anthropogenic impact (sewage effluent, streams, submarine outfall and beaches for recreational use with no contribution from other sources). Results showed that both the structure and composition of the species assemblage varied significantly between sites. The AMBI and M-AMBI index reflected good environmental health at all beaches, categorizing all sites as ‘good’ (or slightly disturbed), except Quequen site which was categorized as ‘poor’ (or heavily disturbed). This site also presented a composition of the assembly of functional features characteristic of areas that present contamination by organic matter (low relative mobility, deposit feeders, tubular and/or gallery inhabitants and 1st order opportunistic species). The traditional approach reflected the differences in the community structure of the different beaches and the functional approach complemented this result by showing that the functional traits covered by the different species of the benthic communities are mainly related to the contribution of organic matter that each beach receives (streams, rainwater, effluents or submarine emissaries). |
