Distribuzione dei policheti nello stagno di Calich (Sardegna nord-occidentale): evoluzione a medio termine (1988-1995)

Polychaete distribution on soft bottoms of the Calich Lagoon has been studied. Medium term variations have been analyzed with samples carried out to distance of 7 years (1988-1995). From a situation enough diversified, but gradual, along the gradient external inside of the lagoon in 1988, the polychaete community shows a wider homogeneity in 1995 when the inside stations, colonized by a typical brackish and organically enriched water fauna appears clearly separate from the external ones.