Loss of Ostracoda biodiversity in Western Mediterranean wetlands

Abstract

Abstract The coastal area of Valencia (Spain) in the Western Mediterranean is rich in freshwater and brackish wetlands. These areas are mostly protected for bird conservation but are also highly affected by human impacts. Six shallow lakes located in Ramsar wetland sites of this area were studied in order to assess past and present ostracod biodiversity and relate it to the status of the lakes, taking into consideration the indicator value of these easily fossilizable crustaceans. In all the wetlands studied, ostracod taphocoenoses showed much higher species richness than the corresponding biocoenoses. This is expected from the time accumulative character of the taphocoenosis, but the trend is clearly evident in the most disturbed sites which indicated loss of ostracod diversity owing to human impacts. By considering the ecology of most frequent species, multivariate ordination of both tapho‐ and biocoenoses showed trends within and between lakes in their limnological status, which were related mainly to water chemistry, and also to temporality and eutrophication to a certain extent. Some lakes have apparently lost most of their past ostracod community owing to an increasing trophic status in some cases and to modifications of the hydrological regime in others. Copyright © 2007 John Wiley & Sons, Ltd.