Die Makrofauna und ihre Verteilung im Nordost-Felswatt von Helgoland

Abstract

Macrofauna and its distribution in the northeastern rocky intertidal zone of the island of Helgoland. 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 subhttoral zone from 23 to 133 species. The upper intertidal is characterized by Littonna saxatilis, Chaetogammarus marinus and Hyale nilssonii. Typical and abundant species of the middle and lower intertidal are Flustrellidra hispida, Littorina mariae/obtusata, Littorina Iittorea, Mytilus edutis and Spirorbis spirorbis. The upper sublittorat zone is characterized by Gibbula cineraria and increasing species numbers of Bryozoa, Nemertini and Opisthobranchia. Only few species (e.g. Dynamena pumila, Laomedea flexuosa, Polydora ciliata, Pabricia 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 as Patella spp., Monodonta lineata, Gibbula umbilicalis, Littorina neritoides, Chthamalus spp., whereas Littorina littorea and Cibbula cineraria are highly abundant. EINLEITUNG

Seasonal occurrence and abundance of caridean shrimp larvae at Helgoland, German Bight

“…In contrast, larvae of these species can'be easily distinguished by a pair of lateral spines on the 5th abdominal somite, which occurs only in T. cranchii larvae (Lebour, 1936;Pike & Williamson, 1961b). Recently, Janke (1986) provided the first information of adult E. occultus from the rocky intertidal at Helgoland. This record can be supported by four adultspecimens which were collected by other investigators during the sample period from test panels at Helgoland Harbour as well as by the presence of their larvae.…”

“…Tambs-Lyche (1962) explained the distribution of adult A. nitescens in Scandinavian waters as a possible transportation from the Enghsh Channel along the continental coast by the general current patterns; this may also be true for their larvae. However, Schellenberg (1928) and more recently Janke (1986), reported adult A. nitescens from Helgoland.…”

“…The comparatively high number of species of shrimp larvae at Helgoland is based on the special biotope around this island: Helgoland is surrounded by the only rocky intertidal zone in the German Bight with its typical flora and fauna (Liining, 1970;Janke, 1986). Pucus and Laminaria species represent the preferred habitat for many different shrimps, e.g.E, pusiolus, E. occultus, H. varians and A. nitescens (Smaldon, 1979), which could explain the larval occurrence of these four species in the studied area.…”

“…However, there have been historical (Dallafc~ Biologische Anstalt Helgoland, Hamburg Torre, 1889;Schellenberg, 1928;Caspers, 1939) and recent studies (Janke, 1986) on shrimps that inhabit the Helgoland region which is the only rocky island in the Southern North Sea. Other studies concerning the biology of these decapods have been conducted along the Dutch coast (Holthuis, 1950;Adema et al,, 1982).…”

Check list of species (algae, invertebrates and vertebrates) found in the vicinity of the island of helgoland (North Sea, German Bight) — a review of recent records

“…Table 1. Literature used for the survey, and explanations of the symbols used in Tables 2-4 Origin of data A: K. Janke (1985Janke ( , 1986 Samples from the eulittoral zone, Samples from the subtidaI zone, Fouling species on Laminaria digitata, Fouling species on Laminaria hyperborea Species of the "Tiefe Rinne" Species of the "Steingrund" {gravel fields}, "Steingrund", additional species on nearby sandy bottoms.…”