Helgoland Marine Research

https://hmr.biomedcentral.com

List of Papers (Total 2,053)

Pollution effects on fisheries — potential management activities

Management of ocean pollution must be based on the best available scientific information, with adequate consideration of economic, social, and political realities. Unfortunately, the best available scientific information about pollution effects on fisheries is often fragmentary, and often conjectural; therefore a primary concern of management should be a critical review and...

Multispecies resource management of economically important marine plant communites of eastern Canada

The annual 45,000 t harvest of six marine plant taxa, consisting principally of the algaChondrus crispus, is worth $ 5 million annually to maritime fishermen. The harvesting techniques enable capture of associated biota and alter the abiotic structure of the habitat. Methods developed to assess ecological impact include permanent transects which are sampled for vegetation...

Die Cnidogenese der Octocorallia (Anthozoa, Cnidaria): I. Sekretionund Differenzierung von Kapsel und Schlauch

The ultrastructural differentiation of capsule and its relation to tube development is described in several Octocorallia species(Alcyonaria: Alcyonium digitatum, Parerythropodium coralloides, Cornularia cornucopiae, Paralcyonium elegans; Pennatularia: Pteroeides spinosum, Veretillum cynomorium; Gorgonaria: Pseudopterogorgia aerosa), all of which have only one type nematocyst. In...

Comparison of electrophoretic and meristic characters of 0-group eel larvae from the Sargasso Sea

Marked differences between continental samples of American and European eels have been detected electrophoretically in allele frequencies at the MDH-2 locus. Starch gel electrophoresis carried out on board F. R. V. “Anton Dohrn” during the eel expedition to the Sargasso Sea in 1979 revealed a similar clear-cut genetic difference in a sample of 0-groupAnguilla leptocephali, thus...

Sewage, green algal mats anchored by lugworms, and the effects on Turbellaria and small Polychaeta

On sandy tidal flats at the Island of Sylt (North Sea) ephemeral mats of green algae covered wide areas in the vicinity of sewage outflows. Algae became anchored in the feeding funnels of lugworms (Arenicola marina) and thus were able to resist displacement by tidal currents. Below the algal mats anoxic conditions extend to the sediment surface. After about one month a rough sea...

Alterations in patterns of excretion and other metabolic functions in developing fish embryos exposed to benzo(a)pyrene

Steelhead trout(Salmo gairdneri) embryos were used as a model to study some of the physiological and biochemical changes which occur following exposure to sublethal levels of benzo(a)pyrene B(a)P, a known environmental contaminant. Embryos were exposed to B(a)P on day 1, 15, or 25 post fertilization, corresponding to the pre-blastula, eyed stage and late organogenesis stage of...

A review of methods for estimating mortality due to parasites in wild fish populations

Six methods are described for detecting mortality due to parasitic infections in natural fish populations. They are: (a) through autopsies; (b) by determining the frequency of infections known to be eventually lethal; (c) by observing a decrease in the prevalence of a long-lived parasite (or permanent scar from a parasite) with host age; (d) by observing a decrease in the...

Seepocken der deutschen Küstengewässer

Barnacles of German coastal waters. An attempt is made to provide a guide for the identification of seven barnacle species occurring in German coastal waters of the western Baltic and the North Sea. Variations in morphological characters observed in sessile adults are described, and figures drawn to differentiate the larvae of the nauplius and cypris stage. The information...

Frequency distribution studies of epipelic diatoms along an intertidal shore

Live and dead cell counts of epipelic diatoms were analysed at 16 sites along a transect crossing a saltmarsh, sandflat, and mudflat at Berrow Flats, Somerset, U.K. Replicate monthly samples were taken from January 1982 to June 1984. The ratio of dead to live cells varied according to position along the transect. Temporal changes of the ratios did not display a cyclic seasonal...

Developmental defects in pelagic fish embryos from the western Baltic

In February/March 1983 and 1984 a survey of pelagic fish eggs was conducted in the western Baltic (Kiel Bight), employing a horizontally towed plankton net (1 m Ø and 300 μm mesh). Maximum egg numbers in the upper meter of the S=21×10−3 salinity layer were 200·100 m−3. The most abundant eggs were cod (up to 142 eggs·100 m−3), followed by plaice (up to 74 eggs·100 m−3) and...

Relative importance of temperature and other factors in determining geographic boundaries of seaweeds: Experimental and phenological evidence

Experimentally determined ranges of thermal tolerance and requirements for completion of the life history of some 60 seaweed species from the North Atlantic Ocean were compared with annual temperature regimes at their geographic boundaries. In all but a few species, thermal responses accounted for the location of boundaries. Distribution was restricted by: (a) lethal effects of...

Some changes in the flora and vegetation of algae in freshwater environments

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 one group of algae over some decades (examples: desmids of two nature reserves between 1925 and 1980, and charophytes in the region of Berlin since 1800) or over longer...

Haemolymph protein composition and copper levels in decapod crustaceans

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 (> 60%); the remaining proteins (in order of concentration) include coagulogen, apohaemocyanin, hormones and antisomes. Moulting, nutritional state, infection, hypoxia and...

Variations in the mussel population of the Dutch Wadden Sea in relation to monitoring of other ecological parameters

The pattern of distribution of intertidal mussel beds is relatively constant over a number of years although their surface area can vary greatly. The abundance of mussels shows much greater fluctuations. In the western part of the Dutch Wadden Sea, west of the Terschelling tidal divide, the amount of mussels on natural beds fluctuated between 1 and 24 million kg fresh weight...

Atmospheric input of inorganic nitrogen species to the Kiel Bight

The atmospheric input of inorganic nitrogen species to the Kiel Bight (south-west Baltic Sea) is characterized. This characterization is based on marine precipitation samples collected at Kiel Lighthouse in weekly intervals during a whole year, using wet-only and bulk-sample methods. The temporal patterns of nitrate and ammonium concentrations are highly variable, with less...

Feeding activities of two euryhaline small-sized fish in a western Baltic brackish fjord

The daily food intake and feeding activities of the common gobyPomatoschistus microps (Krøyer) and the nine-spined sticklebackPungitius pungitius (L.) were investigated in the brackish Schlei fjord. At the investigation site of Olpenitz, salinities varied between 11 and 15‰, and water temperatures between 5 and 18°C during the period of in-situ experiments in 1981 and 1982...

Comparative studies on the thermal properties of a trypsin-like protease intwo hermit crabs

The thermal characteristics of a trypsin-like protease were surveyed comparatively in two hermit crabs,Pagurus bernhardus (Linné) 1758 from the German Bight, andClibanarius striolatus Dana 1852 from the Western Indo-Pacific. In both enzymes, activity is maximal at a temperature around 50°C. Compared withPagurus, the protease inClibanarius is characterized by a considerably higher...

Parasite transfer from crustacean to fish hosts in the Lübeck Bight, SW Baltic Sea

Four helminth parasites out of 19 species found in the Lübeck Bight, Baltic Sea, were chosen for investigations on the transfer from invertebrate to small-sized fish hosts: larvae of the tapewormsSchistocephalus sp. andBothriocephalus sp. (Cestoda) living in planktonic copepods as primary hosts;Podocotyle atomon (Digenea) andHysterothylacium sp. (Nematoda) were found in benthic...

Turnover of postlarval bivalves in sediments of tidal flats in Königshafen (German Wadden sea)

After larval settlement, juvenile bivalves may rapidly re-enter the water column and attain secondary dispersal by byssus-drifting. In order to estimate the quantitative importance of byssus-drifting, the abundance of drifters in the water column, their re-entry into the sediment, and their density in the ambient sediment were measured simultaneously over 3 months on a tidal flat...

A North Adriatic centenarian: The marine research station at Rovinj

The institute in Rovinj was founded in 1891 as the field station of the Berlin Aquarium. It soon gained in scientific importance. From 1911, it was governed by various scientific bodies, such as the ‘Kaiser-Wilhelm-Gesellschaft zur Förderung der Wissenschaften’, the ‘Reale Comitato Talassografico Italiano’, and the ‘Jugoslavenska Akademija znanosti i umjetnosti’. At present, it...

A century of oceanographic and fisheries exploration on the continental shelf off Argentina

A detailed analysis is presented of the main contributions, both local and international, to the fields of oceanography and fishery sciences resulting from exploratory cruises carried out on the continental shelf off Argentina over the last 100 years. The end of the 19th century is chosen as a starting point for this analysis as it marks the beginning of active marine research by...