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This paper describes the construction, validation and application of a mathematical ecosystem model of the western Wadden Sea. This model is based upon the Ems-Dollard ecosystem model, but also includes a two-...
A general simulation model developed for the Ems estuary (a part of the Wadden Sea), to describe the main carbon flow through the foodweb, was applied for monitoring purposes. In this model, the estuary is div...
The mean values on hydrographical parameters in the Wadden Sea of Sylt taken weekly over a period of seven years (1975, 1976 and 1984 to 1988) were compared in order to detect trends in concentrations of nutri...
Results are presented of an on-going monitoring program, started in 1970, of the demersal fish population in the Wadden Sea, Scheldt estuary, and along the continental coast between the Belgian-French border a...
In monitoring, it is of utmost importance to carefully define the purpose, the sampling strategy, as well as the analytical chemical and statistical requirements. Surveys are appropriate for describing the geo...
The situation regarding the distribution and abundance of seagrass, macroalgae and benthic fauna near the island of Sylt in the south-eastern North Sea during the period 1923 to 1940 is compared with that of t...
In the 1980s, significant regional, interspecific and annual differences in contamination with toxic chemicals were found in eggs of breeding birds along the German North Sea coast. In some regions residue lev...
Over the past 20 years, a tradition has developed in western Europe of carrying out shorebird surveys in estuaries. These counts are mostly conducted by amateur ornithologists, usually well acquainted with the...
Monitoring of the marine environment requires considerable resources. Effective programs providing information tailored to needs are essential. The design of monitoring programs should follow from a clear stra...
Interest in using remote sensing techniques, principally those involving satellite, in Wadden Sea research has centred on attempting a classification of the various sediment surface types present. Unlike most ...
Normal development ofAscidiella aspersa was studied over a period of approx. 24 h at 20°C from egg insemination through metamorphosis of the tadpole larva using Nomarski-optics. Records were made of spermatozoa a...
Larvae of the spider crabHyas araneus were reared in the laboratory at constant conditions (12°C; 32‰S), and their feeding rate (F), oxygen consumption (R), nitrogen excretion (U), and growth were measured in reg...
Variations in haemolymph protein composition and concentration, in copper content and copper distribution in the tissue of decapod crustaceans are reviewed. Haemocyanin is the major haemolymph constituent (> 6...
Reproduction was studied inPseudolithoderma extensum (Crouan et Crouan) Lund (Lithodermataceae, Phaeophyceae) from Helgoland. Both gametophytes and sporophytes are crustose. Fertile gametophytes were found in nat...
Isolates ofStypocaulon scoparium Kütz. were collected from the Gulf of St. Lawrence, Canada and compared in culture to isolates collected from the Atlantic and Mediterranean coasts of Europe. The Canadian isolate...
Experiments were conducted in order to observe the effect of five diets on the population development of the rotiferBrachionus plicatilis Müller under laboratory conditions. Diets were based on baker’s yeast (Sac...
The polychaeteNephtys hombergi has an annual cycle of reproduction. Ovaries were fixed for electron microscopy during the gametogenic phase from September to March, and during the breeding and post-breeding perio...
The morphology of the slender, filiform spermatozoa of 13Protodrilus species of 22 different populations is investigated by light and transmission electron microscopy. All species have two types of spermatoza: fe...
Plankton samples were collected from January 1985 to January 1986 three times per week at Helgoland to study seasonal occurrence and abundance of caridean shrimp larvae. A total of eleven species were obtained...
In the summer months of 1984, 1986, 1987 und 1988, several stations off the west coast of Schleswig-Holstein were investigated with regard to the situation of dissolved inorganic nitrogen. An increase in nutri...
The chemical composition of the ctenophorePleurobrachia pileus was investigated in March, May and July 1981 in Kiel Bight, western Baltic. The results of all determinations yielded low values compared with other ...
The estuarine red alga,Bostrychia radicans, was subjected to osmotic stresses ranging from hypo-osmotic (9.9‰) to hyperosmotic conditions (37.4‰). The growth rate decreased with increasing salinities and showed a...
Artificially inseminated eggs of feral North Sea whiting (Merlangius merlangus) were incubated in the laboratory in order to determine reproductive success. After incubation, two measures for reproductive success...
Field studies on the occurrence of meiobenthos in the water column above intertidal sandflats have been performed near the Island of Sylt in the northern Wadden Sea. Swimming meiobenthos was strongly dominated...
Stage 1 of spermatogenesis in the protandrous polychaetePlatynereis massiliensis is represented by clusters of about 60 spermatogonia which appear in the coelomic cavity. There are no testes inP. massiliensis. Th...
The different secretions of the mouth, the vestibular organs, and the vestibular pits of chaetognaths are shown on scanning electron micrographs of the head ofSagitta setosa. The secreting organs are described an...
Larvae ofTubiluchus corallicola van der Land 1968 were investigated by scanning and transmission electron microscopy. The scalids are sensory organs, each has a bipolar receptor cell with a single apical cilium s...
Changes in the flora and vegetation of algae are discussed with regard to the following aspects: (1) Changes in the distribution of an individual taxon (new colonizations and extinctions); (2) Changes within o...
From the Elbe estuary and the adjacent North Sea coast, 19 species ofVaucheria are on record. Their horizontal and vertical distribution pattern as well as their association with macrophyte communities are descri...
The ultrastructure of the cell covering (amphiesma) of vegetative cells ofNoctiluca miliaris (Dinophyceae) was studied in detail using thin sections. The amphiesma is typically amphidinoid and contains the follow...
During the Polarstern-cruise ARK IV/2 June 1987, in the Fram Strait, dinophytes parasitizing copepod eggs were observed. In the laboratory on board, vegetative reproduction was documented and re-infection ofCalan...
Syltodinium listii is described as a new marine ectoparasitic dinoflagellate. In culture experiments the species was found feeding on eggs of planktonic copepods and rotifers. The dinospore penetrates the host b...
All members of the dinophytePaulsenella are ectoparasites on marine planktonic diatoms. At present three species are known, two of which are described here for the first time. The taxonomy of the type species,P. ...
Young, crustose plants ofDumontia contorta grown in the laboratory from carpospores were transferred in September 1983 to their natural habitat in Lake Grevelingen (SW Netherlands). The number of upright fronds p...
Bonnemaisonia hamifera Hariot (Rhodophyceae, Bonnemaisoniales) from Galway Bay, Ireland has been studied in the field and in laboratory culture. The reproductive behaviour of tetrasporophytes and gametophytes in...
A reassessment of theHypoglossum group (Delesseriaceae, Rhodophyta), with a critique of its genera. Eight genera are assigned to theHypoglossum Kützing,Phitymophora J. Agardh,Pseudobranchioglossum Bodard, andZell...
In coralline algae, anatomy has long been used for generic definition, in addition to reproductive structures. Coralline anatomy is here analysed according to its two main components: cell behaviour and morpho...
The success ofElachista fucicola as an epiphyte ofFucus vesiculosus is partly due to its ability to grow on most parts of the host thallus. Its ability to reach reproductive maturity quickly ensures its fitness, ...
Clonal isolates of the brown algaEctocarpus siliculosus (Ectocarpales) originating from Naples (Mediterranean Sea) and southern Chile were compared in laboratory culture studies. The two isolates showed distinctl...
During recent decades, phytoplankton stock on the one hand and inorganic nutrients (P and bound N) on the other have increased considerably in the southern North Sea, as demonstrated at a permanent station (si...
Thirty two isolates ofStromatella monostromatica (Dangeard) Kornmann were studied in unialgal culture; extensive morphological variation was documented. The shape of bicellular germlings and development of young ...
Early phycological research on the island of Helgoland was performed by amateur phycologists from the adjacent coastal regions of Germany (Bremen, Hamburg, Lower Saxony and Schleswig-Holstein). These pioneers ...
In traditional chlorophytan systems the organizational level was the primary character for the distinction of main groups (classes and orders). For instance, in Fott (1971), the flagellate level corresponds wi...
The faunal colonization of the leaves and inflorescences of intertidalZostera marina L. and of the ambient water has been studied at the Island of Sylt (North Sea). The abundance of the snailLittorina littorea L....
During summer 1982 and 1983, measurements on the chemical composition and biomass parameters ofAurelia aurita from Kiel Fjord, Western Baltic, were made. The relationships between size vs. wet weight and wet weig...
The salinity tolerances of Baltic and Atlantic populations ofFucus vesiculosus andChorda filum have been measured using net photosynthesis as an index of tissue damage. AtlanticFucus proved to have a broader sali...
Ordination by Reciprocal Averaging (RA) and Detrended Correspondence Analysis (DECORANA) have been applied to problems of distribution of marine algal floras. The limitations and effectiveness of such methods ...
189 species of seaweeds have been recorded for the Atlantic archipelago of the Azores (114 Rhodophyceae, 41 Phaeophyceae and 34 Chlorophyceae). Ten of these have been described as endemic algae. The taxonomic ...
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