ALBERT

Description: THE rare deep-sea octopod Cirrothauma murrayi Chun 1910 was first described from a single specimen caught during the Michael Sars Expedition of 1910 (ref. 1). Until now it has been caught only four more times2. We describe here three specimens of this species that were recently caught during biological cruises of RRS Discovery (Fig. 1). All of these animals, including the Discovery ones, have been caught at depths of more than 1,500 m, except one that was dip-netted through the ice of the Arctic Ocean3.

Description: THE Sierra Leone Rise, located in the east equatorial Atlantic, forms a discontinuous chain of seamounts as shallow as 2 km extending with a general NE–SW trend from near the Sierra Leone coast of Africa, to the St Paul fracture zone near the Mid-Atlantic Ridge (Fig. 1). The origin of this feature has remained a topic of discussion. Sheridan et al.1 have hypothesised that the Sierra Leone Rise is a volcanic structure formed at the beginning of the opening of the Atlantic in the early Cretaceous period. The twin features of the Sierra Leone and the Ceara Rises are probably of oceanic origin and were created 80 Myr ago or later in their present-day position with respect to Africa and South America2. The Atlantic ocean exhibits several similar aseismic structures which appear symmetrically oriented with respect to the mid-oceanic ridge, such as the Walvis–Rio Grande Rise and the Iceland Faeroes–Iceland Greenland Ridges. These structures are volcanic edifices having a composition similar to that found in their associated islands3–7. Deep sea drilling of the Ceara Rise8,9 penetrated a basaltic basement of the upper Cretaceous period (Maestrichtian) (Leg 39, Site 354). Similarly, a DSDP hole (Leg 41, Site 366) on the Sierra Leone Rise, penetrated sediments of the same period, without reaching basement10. We report here the discovery of alkali-rich volcanics in an area of the Sierra Leone Rise. The sediment overlying the rock fragments is aged ∼45 Myr.

Description: Projekte: a) Erosionsbeobachtung im Bereich der Veisnäs-Rinne b) Geräteerprobungen für die Reise JASIN

Description: The past 20,000 yr have witnessed tremendous climatic changes, a glacial maximum at about 18,000 yr BP and a climatic optimum centred on about 6,000 yr BP, both of which mark extreme situations for the Quaternary. This paper attempts to show that active sand dunes were extensive 18,000 yr ago. Conversely, it seems that sand dunes were generally dormant 6,000 yr ago. Thus the former textbook concept1,2 of an arid climatic optimum and a pluvially active glacial maximum is reversed.

Description: The intention was to study recruitment of benthic macrofauna to an exposed shore. Two mesh-sizes (1.0 and 0.5 mm) were used. The additional abundance and biomass in the finer sieve show both temporal and spatial variations. Maximum values were found in the autumn and at the shallowest station (5 m). The reasons for this are discussed.

Description: In 1975 and 1976 at two stations in the Arkana and the Bornholm Sea the dynamics of the plankton development were studied. The annual course of the measured biological parameters shows peaks of phytoplankton productivity in spring and summer, and of zooplankton in summer. In spring also the phytoplankton biomass reaches a maximum while in August only low chlorophyll values could be observed. In summertime the pelagic system is characterized by an equilibrium state. In autumn after a possible autumnal bloom of phytoplankton all biological parameters sink down to a winter level.

Description: Nitrogen fixation measurements carried out in 1974 and 1975 in the Baltic Sea showed that heterocyst fixed nitrogen c. 3.5 pg (2)-1. According to our preliminary calculations the amount of nitrogen fixed in 1974 in the northern and central Baltic proper was c. 100000 tons.

Description: In 1970/1971 zooplankton was collected monthly at 33 stations in Kiel Bay by means of a Bongo net equipped with 300 µm gauze. Adult copepods were separated into species and sexes. Eleven species were found of which seven were dominant. A succession between winter-spring species (Temora longicornis, Pseudocalanus sp., Acartia bifilosa) and summer-fall species (Centropages hamatus, Paracalanus parvus, Acartia longiremis, A. tonsa) took place. Total abundance varied considerably between the stations. Usually female copepods were more frequent than mal es (up to 85%), with the exceptions of Temora longicornis and Centropages hamatus, which showed a sex ratio of about 1: 1. The sex ratios of Acartia bifilosa and A. longiremis were related to the concentration of the population.

Description: Solutions of detergent or crude oil of 10 ppm, 50 ppm, and 100 ppm after 48-96 hours of exposure induce significant changes in the ionic composition of the hemolymph of the shrimp Crangon crangon and the crab Rhithropanopeus harrisi. The concentrations of sodium, calcium, and chloride ions decrease, whereas the concentration of potassium increases in both species exposed to both pollutants. - The magnesium ion concentration decreases in the hemolymph of the shrimp incubated in solutions of detergent and in the crab incubated in the water containing crude oil. - lt is suggested that changes of the ionic composition of the hemolymph of the studied shrimps and crabs under influence of both pollutants are possibly brought about by alteration of cell membrane permeability and action on some enzyme activities.

Description: The filtration, feeding and assimilation rates of the zooplankton consisting largely of copepods in a shallow eutrophic bodden south of the Darß-Zingst Peninsula (salinity: 5-7‰) were determined under field conditions with the help of 14 C-labelled phytoplankton. During the zooplankton maximum in May (biomass: 2.13 mg dry weight/l), the feeding rate was up to 53.63% of the primary production. The zooplankton production calculated from the experimentally determined assimilation rates was not more than 6.5% of the primary production. The continuously available substantial amounts of detritus resulted in an extraordinarily low grazing rate. 0.39-3.63% of the seston present were removed from the water body daily by filtration. The studies show that the zooplankton also plays an important role in the ecosystem, at least part of the time, even in severely eutrophic landlocked coastal waters.

Description: Kassari Bay is of a specific character, a relatively isolated, sheltered and shallow sea area where the sediment mainly consists of clay and sandy clay. The main communities are the association of the loose-lying red algae Furcellaria fastigiata and Phyllophora brodiaei f. angustissima and the association Zosteretum marinae and its variant which is rich in red algae. Areas with dense vegetation alternate with areas almost without vegetation, or where only single tufts of red algae or some charophytes and phanerogames are found. The floristic list contains 24 taxa, 5 of them are phanerogames. Sphacelaria radicans is a new taxon for the Estonian flora.

Description: Subject of the experimental investigations are the effects of chronic toxicity exerted by the following pollutants of industrial origin on some animals from the Bay of Gdańsk: 1. phosphogypsum; 2. some detergents, i.e. a commercial product "SOLO", a mixture of nonionic and anionic surfactants (for household purposes), and an oil-spill remover Gamlen "CW" Solvent; 3. crude Kuwait oil and one of its derivatives, the fuel oil No. III. -The experimental animals are: Crangon crangon L., Rhithropanopeus harrisi (Gould), the crucial carp (Carassius carassius L.), the pike (Esox lucius L.) and the perch (Perca fluviatilis L.). Beside these inhabitants of the Bay of Gdańsk, also carp fry is used in one of the experiments. -The pollutants mentioned above induce sublethal changes in: the enzymic system, the reproductive activity, embryonic and larval development. Additionally, degenerative changes in the ultrastructure of crustacean brain and pathological disturbances in function and structure of isolated mitochondria could be observed. The general conclusion is that chronic sublethal toxicity may severely affect or even destroy some marine ecosystems.

Description: A 30 sample unit soft-bottom monitoring station was compared to corresponding 5 sample unit stations in the Åland archipelago in the northern Baltic Sea. The samples of macrozoobenthos were taken with an Ekman-Birge bottom-sampler (0.03 m2). The dynamics of the species populations were tested by analysis of variance during a period from 1972-1975 at the five-unit stations. Most of the differences in the mean densities were not verified. Estimation of a minimum sample size was made for the species at the 30 unit station. The spatial distribution of Macoma balthica makes it a species that is easy to sample. lts estimated minimum number of samples units needed for recording a 50 % change in population desity is nine. The other species require a larger number of sample units. The results show the low level of precision when measuring gradual changes of the benthic assemblages using a sample size of five units on soft bottom macrofauna.

Description: In coastal areas or estuaries cadmium-contents of water and sediments may be distinctly increased. The acute toxicity of Cd to sensitive organisms is strongly modified by environmental factor combinations occuring in the Baltic. This could be demonstrated with hydroid polyps. In comparison with other species and developmental stages, up to the present, Laomedea loveni proved to be the most sensitive test species to Cd. Within the ecological range the sensitivity to Cd inceases with higher temperatures and lower salinities. At these conditions not only the rate of accumulation of Cd is enhanced, but the protoplasmic sensitivity is increased to internal metal concentration. In longterm experiments with Clava multicornis the modifying effect of temperature and salinity decreases during the course of some weeks. - Contrary to cnidarians, many molluscs are able to accumulate high concentrations of Cd without signs of physiological damage. In many places of the Western Baltic the levels of Cd in Mytilus edulis are higher than in comparable individuals from localities of the North Sea coast. There are also correlations of Cd-contents of mussels with depth of their locality, size and season. Of the mussel's organs especially digestive diverticula and kidney accumulate the metal. Preliminary results with ion exchange - and gel filtration chromatography of the mussel's proteins suggest the occurence of special Cd-binding proteins, e.g. in the hepatopancreas, as a main reason for the high tolerance of M. edulis to cadmium.

Description: This pilot study was carried out to determine the duration of exposure time taking into account the complex interactions in the ecosystem and to test the aptitude of artificial hard substrates as far as surface-texture, size and shape of the substrates are concerned. In depths of 10.0 and 20.0 m concrete tubes 1.0 m long and 0.5 m in diameter were exposed for four years. Colonization was observed by scientific divers and recorded by photography.

Description: A coralline alga from the Baltic (Belt Sea, Samsö) belonging to the genus Phymatolithon has been investigated. The mineral skeleton consists of magnesium calcite and shows the following composition (expressed in percent of the dry weight): 94-96% skeletal carbonates, 4-6% organic matter, 32.1-33.4% Ca, 3.3-3.5% Mg and 0.15-0.17% Sr. MgC03 determined by the peak shift method (X-ray diffraction) is in the region of 10-11 mol % . The kinetics of 45Ca uptake consist of a fast step and a low step. The fast step is due to equilibration of isotope with the soft tissues and spaces between cells. The slow step is attributed to net deposition of calcium in the skeleton. From the rate constant of the slow step calcium net deposition was found to be 5.6 1 μg Ca/g dry weight/h or 14 μg CaC03/g dry weight/h. Pulse chase experiments show that the calcification is the resultant of calcium exchange between the alga and the seawater. Light-dark calcification ratios are in the range of 1.1-1.3. The O2 production amounts to 0.04 mg 02/g dry weight/h at an irradiance of 0.085 KW/m2. When expressed per unit weight of total organic matter, this assimilation rate would fall into the range commonly found for other noncalcifying Rhodophyta. The results form the basis for further work on calcification mechanism and CaC03 production in coralline algae.

Description: Using the mean annual variations in temperature and oxygen content at ten stations in all parts of the open Baltic proper, relations between phytoplankton spring bloom and maximum oxygen content in the near-surface layer are pointed out. By means of the calculated times of the oxygen maxima and the observed times of the spring blooms, regional peculiarities of the three fundamental areas of the Baltic proper - Arkona Sea, Bornholm Sea and Gotland Sea - are explained. - The results show that there is a clear connection between phytoplankton spring bloom and maximum oxygen content. Furthermore, the longer the phase lag between oxygen maximum and temperature minimum, the longer the period of higher oxygen content in spring.

Description: Nitrogen (C2H4)-fixation in planktic heterocystous blue-green algae was measured in the Askö area throughout the summer 1976. -Temporal variations in total number of heterocysts, heterocyst frequency, heterocyst activity, acetylene reduction and primary production are discussed. - The amount of nitrogen fixed is estimated to 0.6 gN/m2 x year.

Description: The level of oxygen consumption of a Baltic population of Mesidothea entomon was determined in salinities of 1,6.5 and 15‰ and at temperatures of 5°C and 15°C using males, ovigerous females and non-ovigerous females. No significant dependence was found between respiration and salinity. The mean oxygen consumption is of the same order of magnitude as or Baltic marine isopods in general. lt decreases towards the autumn. The oxygen consumption remains at the same level independent of the oxygen concentration in the water until this falls below 2 mg per litre.

Description: The macrofauna of the red algal zone of Kiel Bay is quantitatively investigated for the first time. 109 species were found of which 68 can be considered as genuine inhabitants of the phytal zone. The classification of the phytal fauna according to locomotory and feeding type, their abundance and biomass relative to water depth and their value as fish food were investigated in more detail.

Description: The Baltic Sea is one of the largest brackish water areas in the world, and osmotic stress has severely reduced the number of species in its benthic macro-and meiofauna. This leads to an almost uniquety simple benthic ecosystem. - The benthic macrofauna shows a steep north to south increase in biomass, from mean values of about 1 gm-2 wet weight in the Bothnian Bay, to over 100gm-2 above the halocline in the northern Baltic proper, and even higher values in the southwestern Baltic. Meiofauna biomass is much less variable, and increases only from about 2 gm-2 wet weight to about 6 gm-2 along the same gradient. There is also a north-south gradient in phytoplankton primary production, with an increase by a factor of about 3 to 6. Very low salinities (2-3‰S) exclude filter-feeding bivalves from most of the Bothnian Bay, explaining in part the extremely low biomasses in the north. When filter-feeders are substracted, the benthos-feeding macrofauna biomass still increases more from north to south than the primary production, while the meiofauna biomass, on the other hand' increases less. Calculations are presented which indicate that the total resource use by benthos-feeding macro + meiofauna increases rounghly in proportion to the primary production. The observed shift in dominance from meiofauna to macrofauna is attributed to meiofauna being competitively superior in low food environments (Bothnian Bay), while in richer environments predation by macrofauna limits meiofauna populations (Bothnian Sea, Baltic proper). -Most of the Baltic shows strong salinity stratification, with little or no oxygen present below the primary halocline. This leads to an oxygen-dependent zonation of the fauna, with macrofauna disappearing at higher oxygen levels than some of the meiofauna. Nematodes in low numbers persist even in areas which have been anoxic for long periods. -The secondary productivity of the widely distributed Pontoporeia community is described, and it is concluded that the Pontoporeia populations are primarily food limited, and that the benthic system is intimately coupled to the pelagic system, and may respond to events in the plankton within weeks. -Attempts to estimate the energy flow through the benthos of the Askö-Landort area (N. Baltic proper) indicate that 40 -60gCm to fuel the benthos. - Finally, direct interactions between macro- and meiofauna are discussed. The evidence for control of meiofauna populations by macrofauna predation is suggestive, but not yet conclusive. Examples are also given of more positive interactions between macro- and meiofauna, and it is proposed that a proper balance between different size classes of benthos may be necessary for efficient remineralization.

Description: In summer the effects of ferry traffic in the southern Åland archipelago on animal number and biomass is less pronounced in the Fucus zone than in the Cladophora zone. - In the autumn the combined effects of wave action and low temperature are shown to cause a differentiated effect in exposed and unexposed sites, the number of macroscopic animals beeing reduced at an earlier stage in the former. On a qualitative basis Gammarus sp. and ldotea baltica in addition to Mytilus edulis best endure the mechanical stress induced.

Description: Dynamics of Baltic ecosystems and causes of their variability are discussed and special attention is paid to the use of ecological models as a tool for research and management. - The causes of the observed changes in salinity, temperature, and oxygen of the deep water of the Baltic Sea are reviewed and discussed. - The work has led to the formulation of a hypothesis by which it appears possible to explain the oxygen development and the long-term development of other hydrographic components. The analyses indicate that the change of the level of the interface from - 80 m at the beginning of the century to about - 60 m today has increased the quantity of dead organic matter sinking down through the halocline as a consequence of the increased area of contact between the surface water and the deep water. The increased contact area has led to a corresponding increase in all fluxes through the halocline driven by turbulent gradient diffusion including an increase in the upward flux of nutrients. This has led to a fertilization of the surface water which has increased organic production in the surface zone. This in turn increases the amount of dead organic matter supplied to the deep water. At the same time the temperature increase has increased the rate of oxygen consumption. The net result is that oxygen in the deep water is being consumed at a much higher rate today than previously. lt is estimated that the rate of consumption has increased about 110% since the end of the last century. This implies an increase in the primary production of about 40%. - The supply of oxygen to the deep water has increased primarily as a consequence of the increase in the area of contact between the surface water and the deep water, and secondly as a consequence of an increase in the vertical oxygen concentration gradient. However, the rate of increase of supply has been smaller than the rate of increase of the consumption. The relative difference between the consumption and the supply has increased from 0 at equilibrium conditions at the end of the last century to about 10% today. Although this change in the balance between supply and consumption appears to be marginal, it is nevertheless sufficient to bring about the dramatic decrease of the oxygen concentration in the deep water from about 3 ml/l at the end of the last century to close to O ml/l today. - The model introduced represents a preliminary step towards a Baltic model, which necessarily must take the changing position of the halocline and related effects into account.

Description: The study describes the results of zooplankton sampling during a short period of the International Baltic Year at station F 81 (BY 15 A) in the Gotland Deep. An analysis has been made of the abundance at different depths of the commonest species belonging to the groups: Copepoda, Cladocera, Rotifera, and "others". A clear diurnal pattern could be distinguished mainly for the copepods, which were strongly dominant. Their vertical distribution showed both interspecific differences and intraspecific differences between developmental stages. The cladocerans were still very rare at that time of the summer, their numbers being too low for any definite conclusions.

Description: In the individual parts of the Baltic Sea the vernal bloom of phytoplankton starts at different times. An attempt is made to explain these temporal differences by means of the hydrographical differences of the regions. lt is shown that in the western Baltic and in coastal areas the start of the bloom depends on the increasing radiation when sufficient nutrients are available. In the deeper parts of the Baltic, however, the reduction of the vertical convection together with sufficient light and nutrient supplies is the necessary condition for the outburst of phytoplankton. This lessening of vertical convection is indicated by a decrease of the ratio depth of mixed layer to depth of euphotic zone. The mass development, that means the rapid growth of phytoplankton biomass, is possible when the mixed layer tends to be equal to or less than the euphotic layer. For this thesis examples from different regions of the Baltic and of the North Sea are given.

Description: Phallodrilus monospermathecus, a typical interstitial oligochaete from Baltic and North Sea beaches, shows a characteristic microdistribution preferring the moist layers usually slightly above ground water which are sufficiently supplied with water and oxygen, protected against wave action and devoid of hydrogen sulfide. - Ecophysiological experiments testing the resistance against temperature, salinity, alcalinity, and hypoxia proved the populations to be extremely euryecous tolerating single factors far beyond their natural range. However, combinations of adverse factors reduced the tolerable limits, especially those of salinity, considerably. - In boreal climate, the habitat fluctuations for many physiographical factors apparently lie well within the tolerable range of the populations. Hence, the distributional pattern of Ph. monospermathecus from Baltic and North Sea beaches must be ascribed mainly to long-term and preference reactions and probably also to biotic factors (food supply, competition), and is less definable by short-term tolerances. This is in contrast to conspecific populations from Bermuda beaches. Here, the subtropical climate shifts the maximal oscillations of physiographical parameters close to the tolerance limits which makes the field distribution of the population explicable already by short-term survival tests (GIERE, 1977a). - Considering the differing distributional limits of Ph. monospermathecus in their climatically diverse habitats, the nature ot ecophysiological adaptation in this ubiquitous meiobenthic species is discussed.

Description: A working group of the Delta Institute at Yerseke, The Netherlands, studies the ecosystem of saline lake Grevelingen, a former estuary. The theme of the group is the cycling of organic matter in the two phases of the Grevelingen. The pool of particulate organic matter in the Grevelingen estuary (385 g C m-2 yr-1) was fed from various sources. The amount of organic carbon from the North Sea, entering the estuary as detritus equalled the in situ primary production. After the closure of the estuary the import of organic matter from the North Sea was completely cut off. Overall yearly production of the phytoplankton was not notably influenced by the closure, notwithstanding the large changes in environmental conditions. The significance of the phytobenthos production increased considerably. The total amount of organic matter available for consumers, decreased by roughly 40% to a level of 235 g C m-2 yr- 1. In the estuary net production of macrozoobenthos was estimated at 28 g C m- 2 yr-1. This production was almost divided by a factor two after the closure, just as the amount of food available. Changes in the feeding habits of birds may reflect the often less striking changes in the lower parts of the foodchains. Herbivore bird consumption has increased more than 20 fold after the closure. Consumption of zoobenthos showed a threefold decrease whereas the predation by fish-feeding birds increased about a 30 fold after the closure. The change from an estuarine into a stagnant saline ecosystem, bordering the North Sea, resulted in a sharp decrease in the amount of organic matter available as food, and a shift in the relative significance of predominant species.

Description: The distribution of the polychaete genus Nephtys in Kiel Bay was investigated using the 'stratified random sampling' method. The results revealed a distinct distribution pattern of the three occurring species according to sediment type. The inflowing North Sea water acts as an additional factor affecting the distribution. Niche separation of the genus Nephtys takes place by the combined action of two different mechanisms: preference for certain sediment types and tolerances to hydrographic factors such as reduced salinity and oxygen concentration.

Description: A respirometer for small benthic marine invertebrates is presented. The advantages of this construction are: compactness and easy transport of the equipment, small respiration chamber, entrance and exit electrodes close to respiration chamber, exact temperature control and equilibration of the experimental medium, exact regulation of the flow-through speed, digital display of consumed O2 values. The equipment is suitable for long-term measurement of O2 consumption by benthos organisms in low oxygen conditions and for a rapid picture of the reaction of experimental animals to abrupt changes in their environment (e.g. temperature, salinity, composition of the medium). Procedure for experiments involving a lowering of the O2 content of the medium is explained.

Description: The concept of grain size is critically reviewed and it is demonstrated that the conventional sieve method has some serious, system-inherent shortcomings. Sieve diameters do in many cases not reflect the requirements set by the theory on which they are based. The advantages of an alternative method of size analysis are discussed, in which the settling velocities of sedimentary particles in water are measured. These are then converted into standardized size equivalents and it is argued that the hydraulic nature of settling diameters provides more meaningful results for the study of depositional processess and animal-sediment relationships. A low-cost settling tube system, that is easy to build and simple to operate, is presented. lt is extremely fast when compared to conventional sieving and provides a significantly higher resolution of grain size distributions. The data is ideally suited for the application of moment measures for the computation of grain size statistics.

Description: Plankton samples were taken nearly every month in the years 1970/71. The neuston net sampled the surface plankton and the bongo net the rest of the water column. In total 32 species were found, most were numerically insignificant. The most abundant species were gobiids (more than 51 % ot total) followed by herring, sandeel, Onos and Pholis. Commercial species e.g. plaice, flounder or cod were rare. The majority of the fish larvae did not show a preference for the surface. Only Belone, Gasterosteus and Cyclopterus were caught almost exclusively in the surface layer.

Description: The material for this paper was collected from Gdansk Bay in November 1976 and January and March 1977. Hauls were taken from depths of about 5 metres, then every 10 metres from 20 to 100 metres. The frequency with which particular items of food occurred was calculated from the results of analyses of gut contents. The extent of digestion of food and amount of empty guts in the fish investigated formed the basis for estimation of feeding intensity of P. minutus. The greatest number of empty stomachs was found in January 1977 and the greatest quantity of food sampled during that period was found in fish taken from a depth of about 5 metres. The feeding intensity was about half this at greater depths (30-100 m). - The composition of food taken by P. minutus changed distinctly with depth, Neomysis integer and Nereis diversicolor predominated at smaller depths, whereas Antinoella sarsi was most numerous at greater depths. During the period in question, the diet of P. minutus was found to have a steady composition in fish taken from 70-100 metres and to be most varied at intermediate depths of 30-60 metres. The greatest number of empty stomachs was noted in smaller fish. Qualitative differences in food intake were not found to depend upon the size of the fish investigated.

Description: Arylsulphatase A and B were isolated from the hepatopancreas of the shrimp Crangon crangon L. after 7 days incubation in 50 ppm of detergent "SOLO". Arylsulphatase A, B-1 and B-2 were isolated from the hepatopancreas of the shrimp C. crangon L. incubated in pure brackish water (salinity 7‰). - Heavy and light fuel oil added to the enzyme in vitro in conc. of 2.0% inhibit the activity of arylsulphatase A in greater degree than arylsulphatase B (14.4% and 5.5% respectively). - Detergent "SOLO" (mixture of nonionic and anionic detergents) in the conc. of 0.5% inhibits for 58% arylsulphatase A and for 91% arylsulphatase B, whereas in conc. of 2.0% it inhibits arylsulphatase A for 91.7% and arylsulphatase B for 100%.

Description: Phytoplankton production was measured 19-25 times at three stations in the Sound during 1972 and 1973. The annual production in 1972 was about the same at all stations, 70- 77 g C m-2 yr-1. In 1973 a considerable difference was obtained, 73, 148 and 183 g C m-2 yr-1 for the three stations. The most obvious difference between the two years was observed during spring and summer in the north and central part of the Sound. The production in 1972 was about twice as high, and in 1973 4-5 times as high as previously reported for the Sound. The increased production in the Sound is to a large degree a result of eutrophication, but the natural changes in the unstable area must be considered important. A comparison with production values from adjacent waters and a discussion of factors controlling primary production in the Sound is presented.

Description: The influence of different temperatures and salinities on the toxicity of cadmium has been studied in short- and long-term experiments, using the colonial hydroid Clava multicornis as test organism. Clones were subcultured under prospective T/S-test conditions, applying 12 l recirculating seawater systems with biological water conditioning, glass plates for substratum, and Artemia nauplii for food. The inability of C. multicornis to catch and swallow prey induced by heavy metals was chosen as lethal criterion. - High temperature and low salinity within the ecological range of the species increased the acute toxicity of cadmium, while low temperature and high salinity enabled C. multicornic to resist higher metal concentrations in the water or delayed the appearance of reactions on pollution, respectively. The long-term sublethal threshold concentration of some 200 μg Cd · 1-1 was not affected by combinations of temperature from 5 to 20°C and salinity from 10 to 25‰.

Description: The energy flow of the pelagic part of a shallow water ecosystem is quantified using measurements of global incident radiation, particulate organic carbon, caloric content of the particulate matter, data from other authors on primary production, zooplankton secondary net production and zooplankton tertiary net production as well as several conversion factors from the literature. - The total potential radiant energy in 1973 amounted to 3.46 · 105 kcal m-2 y-1, the phytoplankton net production to 2.66 · 103 kcal m-2 y-1, with an average transfer efficiency of 0.77%. The zooplankton secondary and tertiary net production were 3.58 · 102 and 5.49 · 101 kcal m-2 y-1 respectively. More than 40% of the phytoplankton net production (1.08 · 103 kcal m-2 y-1) was remineralised within the water column, 35% of the phytoplankton net production (9.25 · 102 kcal m-2 y-1) sedimented directly to the bottom. The total transfer to the sediment amounted to 1.55 · 103 kcal m-2 y-1 (corresponding to 58.3% of the phytoplankton primary production), the further transfer to higher trophic levels was 4.34 · 101 kcal m-2 y-1 or 1.6% of the phytoplankton primary production.

Description: An attempt is made to describe the large-scale changes in the benthic soft bottom macrofauna in the deep parts of the Bornholm Basin, the Gulf of Gdansk, the Central Basin and the Gulf of Finland, from the beginning of Baltic zoobenthos research to the present day. The authors also try to correlate these changes with fluctuations in the oxygen content and salinity in near-bottom water layers. The paper surveys the literature and presents recent, earlier unpublished results. During the later part of last century and the first decades of the twentieth century no area of the Baltic Sea seems to have been total ly devoid of macrofauna. Unfortunately there are considerable gaps in our knowledge of the time before the middle of this century. The most striking decline has taken place, generally speaking, after the exceptionally great inflow in 1951-1952, and the subsequent prolonged stagnation. The first records of "dead" bottoms in the Bornholm Basin are from 1948, when no macrofauna was recorded below 80 m. Records from 1954 show that the deepest parts of the Eastern Gotland Basin and the deep area between Öland and Gotland were devoid of macrofauna at that time, but that the deep areas of the northernmost Baltic proper and the Gulf of Finland were still populated. The change continued, and during the 1960s the communities dominated by lamellibranchs in the Bornholm and Gdansk Deeps disappeared, and were subsequently replaced by polychaete cummunities. These have been wiped out during periods of bad oxygen conditions, but quickly re-established when conditions had improved. The lamellibranch community has not been restored. In the Northern Central Basin and the Gulf of Finland the depopulation of the deep bottoms probably began later, in the late 50s. In the 70s practically no macrofauna has been recorded below the permanent halocline in the Central Basin (except the southernmost parts of it) and the Gulf of Finland. During the 60s and 70s the area with periodically unfavourable oxygen conditions has covered about 100000 km2, which is c. 25 % of the total area of the Baltic Sea.

Description: The primary production of two of the most commonly distributed benthic algae in the Baltic proper was measured using different in situ methods (bottles, plastic bags, 14C and O2) during summer. Results on exudation and heterotrophic activity of these exudates have been worked out for Fucus. Low primary production and exudation values are found, while the total bacterial activity seems to be high compared to the net primary production.

Description: Feeding rate in juvenile flounder was measured at different experimental densities of Nereis diversicolor. The results are treated by means of a mathematical model that describes feeding rate as a function of prey density, prey size, fish size and temperature. Feeding rate increases with increasing prey density but at a decellerating rate until a level is reached. The position of the level is lowered with decreasing temperature and fish size and increasing prey size.

Description: This data volume presents a series of planktological observations carried out over a 19-year-period in Kiel Bight in the Western Baltic Sea. Three fixed stations (Boknis Eck: 1957 - 1975, Fehmarnbalt: 1951 - 1960, Breitgrund: 1960 - 1971) were visited at monthly intervals, and the plankton standing stock was investigated in relation to depth and environmental factors, employing a standard observation programme. This consisted in the measurement of temperature, salinity, (density), oxygen, (oxygen saturation), total phosphorus, PO4-phosphorus, seston, protein and chlorophyll a. Additional measurements comprised the caloric content of seston, particulate organic carbon and nitrogen (Boknis Eck: 1973 - 75), as well at dry weight and organic matter of p1ankton, sampled by vertical hauls of three plankton nets of different mesh size: 55 µm, 100 µm and 300 µm {Boknis Eck: 1963 - 75).

Description: A SIMPLE model for continental basement structures at rifted continental margins comprises large fault blocks which trend approximately parallel to, and step down towards, the continental–ocean boundary (for example, see ref. 1). These blocks may be cut by faults which strike across the margin, and, in many theoretical discussions, are shown as being separated from the true oceanic crust by an intermediate zone (see transitional crust of Fig. 3, ref. 2). On many rifted margins these features are deeply buried by young sediments and cannot be stutied in detail. On Goban Spur (Fig. 1), a marginal plateau south-west of Ireland, the young sediment cover is abnormally thin, however, and we have been able to map in detail a 150 km wide continental basement fracture pattern of horsts and grabens using a simple seismic reflection system (160 inch3 air-gun and two-channel hydrophone array). We also suggest a location for the continent–ocean boundary between the Spur and Porcupine Abyssal Plain. There are few previously published data from Goban Spur relevant to our study, although valuable sampling3 and geophysical3–5 results have been obtained north and south of the area.

Description: Es wird eine Unterwasserfernsehanlage beschrieben, die aus Fernsehkamera, Mikrophon und Video-Recorder besteht, die jeweils in entsprechende Gehäuse eingebaut sind. Damit sind Aufnahmen von 20 min Dauer bis zu Tiefen von 50 m möglich. An underwater TV-set is described which consists of TV-camera, microphone and Videorecorder in separate housings. 20 min-recordings down to 50 m are possible.

Description: In the scope of our investigations on the basic processes in a soft-bottom macrobenthos community, as a preliminary test, a series of five 1 m2 metal boxes filled with sterilized sediment from the surrounding habitat was exposed in an enclosed area in the western Kiel Bight at a depth of 20 m from September 1972 until July 1975. The establishment and succession of the soft bottom association in the boxes was followed and compared to the association on the surrounding sea floor by monthly to bimonthly sampling by the diving group of SFB 95. While the number of species increases continuously until a final level of about 20 per 0.1 m2 is reached in January 1974, the values of total biomass (the starfish excluded) fluctuate seasonally being high in autumn and early winter and low in March and April. In a late experimental stage in January 1975, before or just in the beginning period of the regression of the bivalve populations, the association in the boxes (80g wet wt./m2) has only reached 50% of the biomass of the assemblage outside where large long-lived and slowly growing bivalve species contribute 75% of macrobenthos weight. The data of total specimen number fluctuate widely due to oxygen deficiency in late 1973 followed by a high colonization activity by opportunistic spionid species immediately after. According to the dominance in specimen numbers of the major taxononomic groups, three phases can be distinguisted: crustacea (mainly Diastylis rathkei) - sedentary polychaetes (spionids, Pectinaria koreni) - bivalves (Abra alba) together with errant polychaetes (Nepthys spp.). In terms of biomass, however, there is an additional phase of echinoderm prevalence (Asterias rubens) during the last five months. The starfish obviously utilize the bivalve production to a high extent: between 94 and 75 % mortality for the three most abundant bivalve species within six months. For the last six months of the experiment, the net production of all bivalve species is calculated as 24g wet wt./m2, i.e. 0.61 g organic carbon of living tissue, most of which is produced by only three species (Abra alba, Cardium fasciatum and Mya truncata: 22g wet wt/m2.) lt is suggested that predators are of eminent importance in controlling succession and production of the new association. The effects of the experimental conditions on the findings is discussed, and a design for extended interdisciplinary in situ experiments to be carried out from 1976 on, based on the experiences of this first test, is presented.

Description: Zur Simulation des Energieflusses im pelagischen Kreislauf des Flachwasserökosystems bei Boknis Eck wurde ein Differentialgleichungssystem erstellt, mit dem die Parameter Phosphat, Silikat, Diatomeen, sonstiges Phytoplankton, herbivores Zooplankton, carnivores Zooplankton, Fische und Sediment im zeitlichen Verlauf dargestellt werden konnten. Silikat, Phosphat und Sediment wurden als Kohlenstoffäquivalente betrachtet. Im Modell sind Silikat und Phosphat bei den Diatomeen limitierend und für das sonstige Phytoplankton nur Phosphat. Das System enthält 13 Raten, die entweder aus Messungen der Planktongruppe im SFB 95 an der Universität Kiel in den Jahren 1972/73, aus Literaturdaten oder durch „curve fitting" ermittelt wurden. U.a. wurde die Sterberate der Diatomeen und der sonstigen Phytoplankter in Beziehung zur Phosphatkonzentration in der Wassersäule gebracht. Die Geschwindigkeit des Recyclings der Kohlenstoffäquivalente Silikat und Phosphat aus dem Sediment hängt von der Konzentrationsdifferenz der jeweiligen Nährstoffe zwischen Sediment und Wassersäule ab.

Description: Von Juni 1974 bis September 1975 wurde die Besiedlung des sekundären Hartbodens in der Kieler Förde untersucht. Chemische und bakterielle Parameter zeigen eine Zunahme der Verschmutzung des Fördewassers im Innern der Förde. Exemplarisch werden die Artenassoziationen für Falkenstein Düsternbrook und Dietrichsdorf ermittelt. Die Komplexität der Artenassoziationen ist mit dem Grad der Verschmutzung an den einzelnen Stationen negativ korreliert. Die Kieler Förde läßt sich zur Zeit in vier, durch den Grad der Verschmutzung gekennzeichnete Bereiche unterteilen: 1. Einflußgebiet der Schwentine, 2. Düsternbrook, 3. Einflußgebiet des Nord-Ostsee-Kanals, 4. Außenförde. Die Situation in der Kieler Förde ist als „Hafensituation" zu charakterisieren, bedingt insbesondere durch Überdüngung (= erhöhte Produktion) und starke Sedimentation. From June 1974 to September 1975 fouling organisms in the Kiel Fjord were investigated. Chemical and bacteriological parameters show an increase in water pollution inside the Fjord. Interspecific associations are calculated exemplarily for Falkenstein, Düsternbrook and Dietrichsdorf. The result is that there is a negative correlation between the complexity of the interspecific associations and the degree of pollution at the places of investigation. At present the Kiel Fjord is divided into four trophic levels: 1. the area of influence of the Schwentine River, 2. Düsternbrook, 3. the area of influence of the Kiel Canal, 4. the outer Fjord. The ecological situation in the Kiel Fjord may be characterized as a "Hafensituation", especially because of eutrophication and strong sedimentation.

Description: Die vorliegende Arbeit beschreibt ein Meßverfahren, mit dessen Hilfe die Tiefe der Redoxcliskontinuität im marinen Sediment über lange Zeit verfolgt werden kann. Labormessungen haben gezeigt, daß Eh Werte, die mit stationären Elektroden bei einem Langzeiteinsatz gemessen werden, zwar mit einem großen Fehler behaftet sind, aber trotzdem für eine Tiefenbestimmung der RD-Schicht ausreichen. Während der Meßzeit (4 Monate) konnte keine zeitliche Begrenzung der Anwendbarkeit dieses Meßverfahrens durch Verschmutzung oder eine bleibende Vergiftung der stationären Elektroden nachgewiesen werden. The present paper describes a measurement procedure with which the depth of the redox discontinuity in marine sediments can be measured over a long period of time. Laboratory measurements have shown that the Eh values which where arrived at by permanently placed electrodes contained a large degree of error. The method is however, adequate to determine the depth of the RD layer. During the time of measurement (4 months) no temporal limits were evident due to pollution or to permanent poisoning of the stationary electrodes.

Description: Die Stoffwechselgröße von drei bestandsbildenden Muschelarten aus der Westlichen Ostsee - Macoma balthica (L.), M. calcarea (CHEMNITZ), Abra alba (Wood) - wurde in Abhängigkeit von der Sauerstoffspannung vergleichend untersucht. Auch der Reservestoffabbau während der exposition in sauerstofffreiem Wasser sowie die Erholungsatmung nach Sauerstoffmangelperioden wurden gemessen. Die untersuchten Muscheln weisen eine unterschiedliche Temperaturabhängigkeit ihrer Respirationsraten auf. Die Stoffwechselgrößen und Fähigkeiten zur Atemregulation werden im Zusammenhang mit dem Vorkommen der Arten in unterschiedlichen Lebensgemeinschaften der Ostsee diskutiert. Bei Fehlen von Sauerstoff sind die Glykogenreserven der Hauptenergielieferant. Dabei ist der Glykogenabbau deutlich temperaturabhängig. Auch Protein wird abgebaut. Reservestoffspeicherung und -abbau lassen Beziehungen zur unterschiedlichen Anaerobioseresistenz der untersuchten Arten erkennen. Das gilt auch für die Erholungsatmung nach Exposition bei 02-Mangel. Diese zeigt außerdem von Art zu Art eine unterschiedliche Abhängigkeit von der Expositionsdauer sowie von der Expositions- und Meßtemperatur.

Description: In der vorliegenden Arbeit wird anhand von Kohlenstoffkomponenten partikulären Materials versucht, aufgrund des Unterschieds zwischen Seston aus Schöpferproben und Material aus Sedimentfallen qualitative Aussagen über Abbauprozesse zu machen, die bei Sedimentationsvorgängen auftreten. Frerner werden aus dem unterschiedlichen Gehalt an Kohlenstoff in fixierten und nicht fixierten Sedimentfallen Abbauraten berechnet. Die Sinkstoffe weisen gegenüber dem Seston des freien Wassers einen niedrigeren Gehalt an Lipiden und einen erhöhten Gehalt an Humusstoffen und wasserlöslichen Kohlenhydraten auf. Die Sedimentationsrate beträgt in 10 m Tiefe 15 gC m-2 Jahr-2, in 20 m 31 gC m-2 Jahr-1. Die Abbauraten liegen im Jahresdurchschnitt bei 17% (10 m) und bei 9% (20 m) des sedimentierenden Gesamt-Kohlenstoffs, wobei jedoch jahreszeitlich starke Schwankungen auftreten. Mit Hilfe der Abbauraten können turn-over Zeiten für den sedimentierenden Kohlenstoff berechnet werden, die im Jahresdurchschnitt bei 15 Tagen (10 m) bzw. 35 Tagen (20 m) liegen. In this paper the different content of particulate organic carbon compounds in seston and in material from sediment traps is taken as an indication for decomposition processes, which take place during sedimentation of organic matter. Further, a decomposition-rate of particulate organic material is calculated from the different amounts of carbon collected in sediment traps with and without chloroform. Material from sediment traps contains relatively less lipid and more humic acids and water-soluble carbohydrates than does seston from water samples. The rate of sedimentation is 15 gC m-2y-1 in a depth of 10 m, and 31 gC m-2y-1 in 20 m. As an average per year, decomposition rates reach about 17% (in 10 m) and 9% (in 20 m) (of the collected total carbon), but they may vary during the annual cycle. The turn-over time of the sedimented carbon can be calculated from the decomposition rates (the annual average is 15 days in 10 m and 35 days in 20 m).

Description: Von Januar 1973 bis Februar 1974 wurde von den dominierenden Zooplanktonarten der westlichen Kieler Bucht das Trockengewicht sowie ihr Gehalt an organischem Kohlenstoff, Stickstoff und Kalorien im jahreszeitlichen Verlauf untersucht. Zwischen diesen Parametern bestand eine auf dem 0,1 %-Niveau signifikante Korrelation. Zwischen der Fruchtbarkeit der Copepoden ausgedrückt durch den Quotienten Nauplius/Copepode und dem Kohlenstoffgehalt der Copepoden bestand eine auf dem 0,1 %-Niveau signifikante Korrelation. Die kurzfristigen starken Schwankungen im Kohlenstoffgehalt, Stickstoffgehalt und Trockengewicht der Copepoden werden somit durch Perioden erhöhter Eibildung erklärt. Die Sekundär- und Tertiärproduktion wurde berechnet unter Berücksichtigung der natürlichen Sterblichkeit der Plankter und des Wegfraßes durch carnivore Arten. Bei einer Sekundärproduktion von durchschnittlich 33,8 gC m-2 Jahr-1 (V = 33,3) und einer mittleren Tertiärproduktion von 5,2 gC m-2 Jahr-1 (V = 3,0) betrug das Verhältnis von Primär- zu Sekundär- zu Tertiärproduktion bei einer Primärproduktion von 158 gC m-2 Jahr -1 100 : 21,4 : 3,3. The dry weight, organic carbon, nitrogen and caloric content of the dominating zooplankton species of the Western Kiel Bight were analyzed from January 1973 to February 1974. There was a highly significant correlation between these parameters. Between the fecundity of the copepods expressed as ratio nauplii / copepods and the carbon content of the copepods was a highly significant correlation. The great fluctuations within short time intervalls in organic carbon and nitrogen content are thus defined to periods of higher egg-production. The secondary and tertiary production was calculated in regard to the natural mortality and predation by carnivorous zooplankton species. The mean secondary production was 33,8 gC m-2 year-1 (Range R 33,3) and the mean tertiary production 5,2 gC m-2 year-1 (R = 3,0). With a primary production of 158 gC m-2 year-1 the ratio of primary to secondary to tertiary production was 100 : 21,4 : 3,3.

Description: The biomass (weight of protoplasm) and production of the major species of benthic Foraminifera was calculated for the "Hausgarten" area of Sonderforschungsbereich 95. Data from 440 samples collected between 1971 and 1975 were used for these calculations. Biomass production of Foraminifera is 10-90 mg wet weight/m2/y in the turbulent zone and up to 5411 mg/m2/y in the basins. Epiphytic species produce 13-26 mg wet weight/m2/y. These values are higher than those recorded in the literature with the exception of the subarctic. The foraminiferal proportion of total meiobenthos biomass ranges between 6% in the turbulent zone and 63% in the basin.

Description: Ein in situ-Meßsystem für Untersuchungen zum Stoff- und Energiefluß in isolierten benthischen Flachwassergemeinschaften wird beschrieben. Die Messung des Gaswechsels sowie anorganischer und organischer gelöster Substanzen erfolgt in geschlossenen (Säcke) oder offenen (Durchflußsystem) Meßeinrichtungen, die unter Verwendung von flexiblen Plastikfolien konstruiert wurden, um möglichst ungestörte Turbulenzverhältnisse zu gewährleisten. Die Anwendung der Meßeinrichtungen wird anhand von Meßbeispielen erläutert. A measuring system is described for in situ investigations on the flow of energy and matter in isolated benthos communities in shallow waters. Measurements of gas exchange and inorganic as well as organic dissolved matter are carried out either in closed (bags) or open (flow through) devices. Flexible plastic film is used for the construction of the devices in order to obtain favourable turbulence conditions in the systems. Practical application is illustrated by examples of measurements.

Description: Die Beobachtung von Barnea-Populationen auf den Schwebesubstraten (verankerte Unterwasserversuchsplattformen) und vor Boknis Eck (Kieler Bucht) erbrachte, daß isolierte Substratflächen von frei schwimmenden Barnea-Larven besiedelt werden, die Bohrmuschel bei geeignetem Substrat auch in größeren Tiefen zu finden ist und auch dort gutes Wachstum zeigt (durchschnittlich 54,2 mm/30 Monate im Experiment). Bei einer Siedlungsdichte von 162 Exempl./m2 ergibt sich auf den Schwebesubstraten in 19 m Wassertiefe ein Flächenabtrag von 5,2 mm/m2/30 Monate. Aufgrund der weit größeren lndividuenzahl im Flachwasser dürfte der Betrag dort um das 3-6fache höher liegen. Ihr Vorkommen scheint in der Ostsee an besondere Küstenformen gebunden zu sein (Kliff mit submariner Abrasionsplattform mit freiliegendem Geschiebemergel oder Ton). Observations of Barnea populations on submerged substrate platforms and off Boknis Eck (Kiel Bight) showed that isolated substrate patches are colonized by free swimming Barnea larvae. This boring clam is also found in deeper regions when suitable substrate is available, and it also shows good growth (mean 54,2 mm/30 months under experimental conditions). There is an abrasion of 5.2 mm2 30 months on the 19 m depth substrate platforms accompanied by a density of 162 individuals/m2. Due to a far denser population in shallower water the abrasion might be 3-6 times larger than in 19 m depth. In the Baltic the occurrence of Barnea candida seems to be linked to certain features of the coast (cliffs with free patches of till or clay on their submarine abrasion platforms).

Description: Der Salzgehalt der Wassersäule und des Porenwassers in 2-5 cm und 8-12 cm Sedimenttiefe wurden von Juni 1972 bis Oktober 1973 monatlich auf drei Stationen der Kieler Bucht bestimmt. An Hand der Salzgehaltsveräanderungen in Sediment und Bodenwasser wird der Austausch des Porenwassers untersucht. In den beiden ufernahen, in Förden gelegenen Stationen nimmt der Salzgehalt wenige Zentimeter unterhalb der Sedimentoberfläche rasch ab. Dies wird auf Grundwassereinflüsse in den unter dem Meeresboden liegenden Sedimentschichten zurückgeführt. Die Lage der Grenzfläche Meer-/Grundwasser verändert sich mehrmals im Jahr. Dabei verursacht sie einen Verdrängungsaustausch des Porenwassers. Die dritte Station, Eckernförder Bucht/Rinne ist typisch für die Tiefengebiete der Kieler Bucht. Hier steht der Salzgehalt des oberflächennahen Interstitials in enger Beziehung zu dem des Tiefenwassers. Die Auswirkungen des Einstroms salzreichen Kattegatwassers im Sommer 1972 auf die Salzgehalte des Interstitials werden dargestellt. Ein Ansteigen der Salinität war bis in 10 cm Sedimenttiefe festzustellen. Annähernd gleiche Zeiten für Zu- und Abnahme der Porenwassersalinität im Gefolge des Tiefenwassereinstroms schlieBen einen Verdrängungsaustausch durch spezifisch schweres Wasser hier aus. Die bioturbate Aktivität im Sediment der Eckernförder Bucht/Rinne wird dargestellt und ihr Einfluß auf die Austauschvorgänge zwischen Interstitial und Tiefenwasser erörtert. Für den Stofftransport werden die Alternativen des Austausches durch Diffusion von Ionen und durch Vermischen von Lösungen diskutiert. Der Bezug zu den untersuchten Sedimenten und den Auswirkungen auf die Wassersäule wird hergestellt.