Mollusken-Gemeinschaften der Bahía de Nenguange (Karibik, Kolumbien)

Abstract

The Bahía de Nenguange is one of the largest bays (5 km2) east of Santa Marta. The shore of the U-shaped bay is made up of steep slate rocks, interrupted by sandy beaches. The waters within the bay are rather shallow but get deeper to the north; in the western part, which is 10-12 m deep, a platform is situated. The western shore is subject to strong exposure of waves; the eastern half is calmer. On the eastern beach a small stand of mangroves is located. Altogether, 491 species of molluscs were found, belonging to 100 families and 259 genera. 12 molluscan assemblages have been documented: 4 distributed in the intertidal, and 8 in the sublittoral zone. The distribution of the sublittoral coenoses depends on the distribution of the substrates. Numerous microgastropods occur in coarse-grained sediments. Highest diversity was observed on fine and mixed sands. Variations documented in the diversity of the Thalassia-coenosis and of the fine sand-mixed sand coenoses are due to changes in numbers of species, whereas the diversity on ooze is due likewise to modifications in the number of species and to evenness. © 1986 Biologische Anstalt Helgoland.