Abstract

The macrofauna and its distribution in the sheltered, rocky intertidal zone of Helgoland (North Sea) was studied at 9 vertically and/or morphologically different stations from March to September in 1984. Seasonal variations in the communities were described based on each species' “conspicuousness”. A total of 172 species was found. The macrofauna shows a zoned pattern, but also the different substrata, for example, affect its distribution. The number of species increases from the upper intertidal to the upper sublittoral zone from 23 to 133 species. The upper intertidal is characterized byLittorina saxatilis, Chaetogrammarus marinus andHyale nilssonii. Typical and abundant species of the middle and lower intertidal areFlustrellidra hispida, Littorina mariae/obtusata, Littorina littorea, Mytilus edulis andSpirorbis spirorbis. The upper sublittoral zone is characterized byGibbula cineraria and increasing species numbers of Bryozoa, Nemertini and Opisthobranchia. Only few species (e.g.Dynamena pumila, Laomedea flexuosa, Polydora ciliata, Fabricia sabella, Jaera albifrons, Carcinus maenas) occur in the entire intertidal zone. In comparison to other very sheltered shores in Great Britain, which are also dominated by Fucaceae, the macrofauna in the Helgoland intertidal zone lacks several littoral species, such asPatella spp.,Monodonta lineata, Gibbula umbilicalis, Littorina neritoides, Chthamalus spp., whereasLittorina littorea andGibbula cineraria are highly abundant.

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