Project Report: June 2005
The aim of this project was to identify areas of high priority for the conservation of benthic biodiversity of the rocky intertidal systems of Uruguay. Nine sites were sampled along the Uruguayan coast. Within each site, 7 to 10 transects were placed. Along the transect, a sampling quadrate (1 m2) was placed randomly in the intermediate (barnacle fringe) and low (mussels fringe) intertidal zone. The species richness (invertebrates and algae) was measured as the number of species present in each locality. In all the cases the final richness was evaluated from a cumulative species-sampling effort curve.
The main results were:
Species richness (S) increased significantly from the freshwater to the marine region. Within the freshwater zone S was lower than the other sites sampled with one exception. Within the marine region, S ranged from 25 to 33 species, while in the estuarine zone S ranged from15 to 28 species.
A classification analysis, using similarity matrix identified three major groups; the first one is composed by the two westernmost sites of the gradient studied, the second group is formed by Punta Espinillo and the remaining sites were grouped into a third one (see figure below).
|Regions identifiable as targets for conservation
The complementarity index suggested an increase in the similarity of species composition from the freshwater to the marine extreme. In other words, differences between sites of the freshwater were more conspicuous than the differences among sites that formed the marine extreme.
In order to protect and conserve the biodiversity harboured in the rocky intertidal zone of Uruguay it is necessary to distribute protected areas within the different regions, in order to ensure protection to a fully representative sample of regional diversity.
The description of the spatial variability of species richness and composition of the rocky intertidal systems of Uruguay will allow identifying areas of high conservation priority. Furthermore, coastal areas with environmental risks could be detected and environmental impacts could be evaluated due to the existence of baseline data herein provided. The results will be of great utility for the development of conservation and management plans for marine coastal ecosystems. In Uruguay, baseline data on benthic biodiversity is scarce or lacking, making selection of areas or habitats to protect very difficult.
The Uruguayan committee of the IUCN has started working in local meetings about marine issues. In this context, the main objective of the IUCN is "to contribute to the design, creation and management of Protected Areas in Uruguay". The high priority areas identified in this project will be of great relevance for the UICN initiative. Therefore, these results will be presented in local meetings with the Uruguayan committee of the IUCN and all the people implicated in coastal management.
Additionally, the results of this project have been disseminated through local meetings and presentations in regional or local congresses. In particular, a presentation was made in Argentina (in the "Jornadas de Ciencias del Mar, Universidad Nacional de Mar del Plata, Argentina") and a second one in Uruguay (in the "I Encuentro de Ecología del Uruguay en VII Jornadas de Zoología del Uruguay").