THE CUMACEAN COMMUNITY ASSOCIATED WITH A SEAWEED AS A BIOINDICATOR OFENVIRONMENTAL-CONDITIONS IN THE ALGECIRAS BAY (STRAIT OF GIBRALTAR)

In order to know the spatio-temporal distribution of a cumacean commun ity and its role as a bioindicator of different environmental conditio ns, a representative seaweed (Halopteris scoparin), with which cumacea ns are associated, was sampled in different stations in Algeciras Bay during one year.:Five stations were sampled seasonally, and eight envi ronmental factors were tested (temperature, hydrodynamism, silting, di ssolved organic matter, organic matter in silt, suspended solids, comp actness index, and interstitial volume). The physico-chemical study sh owed that the bay comprised an internal and an external areas, while t he spatio-temporal study revealed the presence of three cumacean speci es, Cumella limicola, Nannastacus unguiculatus and Scherocumella longi rostris. There was a clear difference in the distribution and the abun dance of these species. In fact, C. limicola was more abundant in the inner area of the bay, whereas N. unguiculatus was more abundant in th e outer area. Multivariate analyses were performed to explain the stru cture of this community along the different stations of the bay. The s egregation was significantly related to hydrodynamism and algal parame ters (interstitial volume and compactness index).