ALBERT

Description: The pollen record of three marine late Quaternary cores off Senegal shows a juxtaposition of Mediterranean, Northern Saharan, Central Saharan elements, which are considered transported by the trade winds from a winter-rainfall area, and Sahelian, Soudanese, Soudano-Guinean elements, considered transported both by winds and mostly by the Senegal River, and coming from the monsoonal, summer tropical rainfall area of southern West Africa. Littoral vegetation is either the edaphically dry and saline Chenopodiaceae from sebkhas at the time of the main regression, or the warm tropical humid mangrove with Rhizophora during the humid optimum period. Four stratigraphic zones reflect, from basis to top: Zone 4. A semi-arid period with a balanced pollen input. Zone 3. A very arid period with the disappearance of monsoonal pollen, probably from the disappearance of the Senegal River, a very saline littoral plain with Chenopodiaceae, a larger input of northern Saharan pollen from intensified trade winds. Zone 2. A quite humid period, much more so than today, very suddenly established, with a northward extension of the monsoonal areas, a rich littoral mangrove, and weakening of the trade winds. Zone 1. A slow and steady evolution toward the present semi-humid conditions with regression of the mangrove, and of the monsoonal areas toward the south. Tentative datations and correlations with the Tchad area suggested: zone 4: 22,500 to 19,000 years BP; zone 3: 19,000 to 12,500 years BP; zone 2: 12,500 to 5,500 years BP; zone l: 5,500 years BP to top of core. Dinoflagellate cysts display a tropical assemblage wwith mostly estuarine neritic elements and also a weak oceanic component, mostly in the lower slope core 47. Cosmopolitan taxa dominate the assemblage and only a few species point to more specialized environments. Quantitative variations of the assemblage are the basis of stratigraphy which is not similar to the pollen stratigraphy, and an inshore-outshore gradient has to be taken into account to correlate the three cores.

Description: Surface sediments from 5 profiles between 30 and 3000 m water depth off W Africa (12-19° N) have been studied for their sand fraction composition and their total calcium carbonate and organic matter contents to evaluate the effect of climatic and hydrographic factors on actual sedimentation. On the shelf and upper slope (〈 500 m), currents prevent the deposition of significant amounts of finegrained material. The sediments forming here are characterized by high sand contents (〉 60 % ; in most samples 〉 80 %), low organic carbon contents (in most samples 〈 0.8 %), high median diameters of the sand fraction (120-500 μm), and by a predominance of quartz and biogenic relict shells (most abundant: molluscs and bryozoans) in the sand fraction. Median diameters of total sand fraction and of major biogenic sand fraction components (biogenic relict material, benthonic molluscs, benthonic and planktonic foraminifers) co-vary to some extent and show maximum values in 100-300 m water depth, reflecting the sorting effect of currents (perhaps the northward flowing undercurrent; MITTELSTAEDT 1976). In this water depth, biogenic relict material is considerably enriched relative to quartz, the second dominating sand fraction component on the shelf and upper slope, resulting in distinct calcium carbonate maxima of the bulk sediments. The influence of the undercurrent is also reflected in a northward transport of finegrained river load and perhaps in the distribution of the red stained, coarse silt and sand-sized clay aggregates, which show maxima in 300-500 m water depth. They probably originate from tropical soils. Abundant coarse red-stained quartz on the shelf off Cape Roxo (12-13° N) suggests a southward extension of last glacial dune fields to this latitude. Below about 500 m water depth, current influence becomes negligible - as indicated by a strong decrease in sand content, a concomitant increase in sedimentary organic carbon contents (up to 2.5-3.5 %), and the occurrence of high mica/quartz ratios in the sand fraction. Downslope transport, presumably due to the bioturbation mechanism proposed by BEIN & FüTTERER (1977), is indicated by the presence of coarse shelfborne particles (glauconite, relict shells) down to about 1000 m water depth. The fine/coarse ratio (clay + silt/sand) of the sediments from water depths 〉 500 m never exceeds a value of 11 in northern latitudes (19°-26° N), but shows distinct maxima, ranging from 50 to 120, at latitudes 18°, 17°, 15° 30', and 14° N in about 2000 m water depth. This distribution is attributed to the deposition of fine-grained river load at the continental slope between 18° and 14° N, brought into the sea by the Senegal and southern rivers and transported northward by the undercurrent. Strang calcium carbonate dissolution is indicated by the complete disappearance of pteropods (aragonite) and high fragmentation of planktonic foraminifers (calcite) in sediments from water depths 〉 300-600 m. Fragmentation ratios of planktonic foraminifers were found to depend on the organic carbon/carbonate ratio of the sediment suggesting that calcite dissolution at the sea bottom may also be significant in shelf and continental slope water depths if the organic matter/carbonate ratio of the surface sediment is high and the tests remain long enough within the oxidizing layer on top of the sulfate reduction zone. The fact that in the region under study intensity and annual duration of upwelling decrease from north to south is neither reflected in the composition of the sand fraction (i. e. radiolarian and fish debris contents, radiolarian/planktonic foraminiferal ratios, benthos/plankton ratios of foraminifers), nor in the sedimentary organic carbon distribution. On the contrary, these parameters even show in comparable water depths a tendency for highest values in the south, partly because primaty production rates remain high in the whole region, particularly on the shelf, due to the nutrient input by rivers in the south (SCHEMAINDA et al. 1975). In addition, several hydrographic, sedimentological and climatic factors severely affect their distribution - for example currents, dissolution, grain size composition, deposition of river load, and bulk sedimentation rates.

Description: The Baie du Lévrier (some 800 km2, 〈 20 m deep) lies at about 21° N. The climate is arid. Hydrographie conditions are controlled by (1) Trade winds, which largely determine wave base, (2) tidal currents, and (3) upwelling on the shelf nearby. Sediments range from carbonate-poor silty muds to carbonate-rich sands. Below wa ve base sediments characteristically have 〈 30% sand, sand medians 〈 125 μm and 55-80% silt, whereas wave-washed sediments have 〉 70% sand with medians 〉 400 μm. Other dynamic factors, notably tidal currents, may blur the distinction between these two populations. Sources for the terrigenous components are (1) modern aeolian dunes whose sands enter the sea to form a prograding coastal sediment wedge; (2) wind dust deposited as silty muds below wave base; (3) sub-Recent relict material on the seafloor; ( 4) cliff and bank erosion (local); (5) sea bed-load, significant in current-washed areas. Non-terrigenous components include pellets, ooids and skeletal debris. Pellets, incompletely indurated and mainly faecal, form up to 2/3 of the sand fraction in muds below wave base. Relict pellets are rare. Superficial ooids occur in trace quantities in some beach and nearshore samples. Skeletal debris accounts for most of the carbonate sand and also contributes significant quantities of biogenic opal and phosphatic material. Relict and mineralized (goethite and Fe-silicates) skeletal grains are locally important. Like the modern skeletals they are of foramol type. In the modern skeletal sand molluscan material is ubiquitous ( 〈 20% to 〉 90% of skeletal sand) but, as little can be identified further, molluscs as a whole have little interpretative value. Other skeletals form two groups: ( 1) typical of the banks and flanks of the bay, includes barnacles, worm tubes, calcareous red algae, bryozoans and alcyonarian spicules (the two lattcr tend to occur close to rather than on the banks and to lie below wave base rather than in the wave zone as the others do); (2) found in "basinal" sediments below wave base, includes calcarcous, opalinc and phosphatic forms: foraminifers (benthonic and planktonic), echinoderms, ostracodes, sponge spicules, diatoms (planktonic and benthonic) and fish remains. From the relationships between the bank and "basinal" groups five skeletal grain assemblages are recognized and shown to be related to sedimentary facies (ranging from carbonate-poor, silty mud facies with foraminifers, sponge spicules, diatoms and fish remains, to carbonate-rich sand facies characterized by bank group skeletals, particularly barnacles). Within some of the assemblages there are marked and systematic lateral shifts in relative importance of skeletal components. All these features can be interpreted in terms of source and transportability of the grains, some (e.g. barnacle) being moved principally as bed load, while others are carried in suspension. Laterally graded suspensions are proposed to explain the distribution of the components of the "basinal" group and also, near banks (or flanks), of alcyonarian spicules and bryozoans. Proximity to oceanic influences is expressed particularly in fine-grained "basinal" sediments by relative increase of echinoderms, ostracodes and molluscs (particularly Pinna needles) as well as of planktonic foraminifers and diatoms relative to benthonic ones. Significant regional environmental features are expressed in the sediments as follows: Aridity limits terrigenous sediments to a coastal wedge of dune-derived sands, aeolian dust in silty muds below wave base, and products of local cliff erosion. By precluding freshwater "dilution" it allows evaporation to increase salinity and a few ooids form. Combination of offshore upwelling and the Canary Current accounts for the presence of the foramol skeletal association in the tropics, and for the unusually high percentage of biogenic opal (up to 〉 12% of total sample), (cool-water) planktonic foraminifers (up to 〉 25% of total foraminifers), fish debris, and perhaps also of ostracodes. The general water temperature and salinity regime is such that the Baie du Lévrier lies in a critical position on or near the boundaries between major provinces of carbonate sedimentation both for skeletal (foramol, but chloralgal known 150 km to south) and non-skeletal components (normally pellet, but oolithaggregate locally reached).

Description: Geophysical and geological surveys by R.V. "Meteor" (1967, 1975, 1977) and R.V. "Vema" (1973) revealed new information on the seismic stratigraphy and geological evolution of the Mazagan Marginal Plateau. Fragments of a light-colored, mylonitic granite were recovered from the base of the escarpment and interpreted as slivers of foundered continental basement, pushed upwards along landward dipping thrust faults. The upbuilding of a 〉 2 km thick carbonate platform during (? pre-)Oxfordian to middle Cretaceous times kept pace with its fast subsidence (up to 80 m/m.y.). At the foot of the 27-38° steep escarpment we dredged an Oxfordian well sorted algal and foraminiferal limestone which is devoid of any terrigenous components and full of shallow-water organisms; it indicates an euphotic, sublittoral, perireefal environment. Upslope on the escarpment, we infer outcrops of middle Aptian to early Albian quartzose, calcareous and siliceous nanno claystones which reflect an outer shelf setting. Below the outer Mazagan Plateau, seismic evidence suggests that individual reefal bioherms continued to grow above a mid-Cretaceous unconformity, while the underlying carbonate platform subsided below wave base and was covered by Late Cretaceous pelagic sediments. A Paleogene (? Paleocene) and an Oligocene unconformity can be distinguished on seismic records and correlated to Cretaceous and Tertiary outcrops on the shelf off EI Jadida. Paleogene glauconitic marls and thin Neogene hemipelagic sediments top the plateau and represent a slope environment of deposition.

Description: Taxonomical study of the Bryozoa collected during the cruises of R. V. "Meteor" near the French coast (Atlantic and Channel) and the coastline of Mauritania. First indications of Arachnoidea annosciae n'HONDT and GERACI, 1976, Onychocella antiqua (BUSK, 1858) and Cribrilaria flabellifera (KIRKPATRICK, 1888) in the temperate region of the North Atlantic.

Description: A study of recent publications on ichthyoneuston of subtropical seas showed that this fauna is neither regionally nor seasonally uniform. Available material of abundant and characteristic species off Northwest Africa was re-examined under this aspect. This material was collected during five German expeditions (1967-1973) between 20° and 36° N and between the coast and 30° W. It includes 366 hauls that could be utilized for qualitative analysis; out of these 333 hauls yielded quantitative information. Based upon variation in geographical and hydrographical factors, distribution of sampling locations and zoogeographical considerations, the study area was divided into five subregions (two neritic and three oceanic), each represented by a different number of samples. A clear faunistic boundary appears between neritic and oceanic subregions. This boundary is related to water depth and distance from shore. It is sharp for neritic species. It is also sharp for mesopelagic fishes as they do not occur in water shallower than the slope, whereas oceanic-epipelagic taxa are less affected by this boundary. Latitudinal zonation is also evident as it is a function of hydrographic factors, especially temperature, probably showing seasonal variations. The latitudinal boundary is less pronounced than the neriticoceanic one; simplified it is assumed as running through the Canary Islands region. In all subregions, ichthyoneuston abundances appear to be highest during winter months. Maximum of abundance is produced by spawning that is restricted in many species to this season. The five most common species constituted more than 80% of the total catch during winter. Their proportion decreased to less than 60% in warmer months due to the immigration of less common (largely tropical) species and the mortality and ontogenetic emigration of animals born during winter. Seasonal differences in diversity did not prove significant as species number in ichthyoneuston catches is generally high. Seasonal trends are conspicuous for typical species only and are discussed. The northwest African current system probably causes considerable drift in ichthyoplankton. This raises the question as to how stocks survive despite drift of early life stages. This problem is discussed for characteristic taxa. Depending on the species, several mechanisms acting either singly or in combination are possible: 1. Adults of tropical neustonic forms actively migrate into the study area in summer, passive southward transport of early stages being a necessary condition for survival during other seasons. 2. Southward transport of species performing diurnal vertical migrations may, in certain areas, be reduced if such species reach the poleward undercurrent and remain in it during part of the day. 3. South of Cape Blanc, inshore eddies and the temporary surface countercurrent may permit a longer stay or return transport. This mechanism is probably effective for neritic euneustonic animals.

Description: This paper deals with the presence and distribution of Thecosomatous Pteropods in the Indian Ocean. 122 plankton-samples, taken by R.V. "Meteor" during the International Indian Ocean Expedition (IIOE) in 1964-65 were investigated. They contain a total number of about 45000 Thecosomata, belonging to 22 species and 5 families. Some species (e.g. Creseis acicula and Limacina inflata) are common in the entire area, others (e.g. Creseis chierchiae and Desmopterus gardinieri) show a quite distinct distribution. From several species only one single specimen was captured, others are completely lacking in the collection though they have been reported frequently from the same area by other expeditions. This may be due to seasonal variations and to the fact that to bathial tows were taken. In spite of these restrictions the extensive material from a relatively small area offers the possibility to compare specific and nonspecific features in related species and to question their taxonomic value.

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

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: Oceanographic measurements by groups from the Federal Republic of Germany contributed mainly to the C-Scale Experiment (centered at 9° N, 23° W) and the Equatoria1 Experiment. In this paper the data are presented that were obtained from the moorings F 1 and F 2 in the C-area. After a short discussion of instrument problems, data processing and statistical analysis, the data are presented graphically as time series, progressive vector diagrams, frequency distributions and spectra of horizontal kinetic energy and of temperature variance.

Description: The results of measurements on currents and stratification obtained by FRV "Anton Dohrn" during the GATE-Equatorial Experiment are presented in graphical form. Remarks on data processing arid errors involved are made accordingly.

Description: We report, numerically and in graphical form, measured tritium concentrations from five hydrographic stations in the North Atlantic. Fairly homogeneous concentrations are observed in a surface layer typically 400 m deep. In the thermocline, concentrations decrease steadily down to the a σθ = 27.3 density horizon, and are more variable further down. The tritium in the lower part of the thermocline originates from the Subarctic Intermediate Water and the Mediterranean Water. There is a relative tritium maximum associated with the Mediterranean Water on the easternmost station of the section. In the deep water (σθ 〉 27.8), concentrations east of the Midatlantic Ridge are close to the limit of detection down to 2500 m, and undetectable further down, while west of the ridge tritium is found throughout the water column. The deep water tritium is associated with the deep-water advective cores of Arctic origin. The present tritium data can serve as northern boundary values in attempts to use tritium in studies of the North Atlantic main thermocline dynamics. The present data together with data from the literature point to a general division of the North Atlantic main thermocline into two layers separated by an isopycnal surface near σθ = 27.3.

Description: During the international "Overflow-Expedition" 1973 on R.V. "Meteor" oxygen concentrations in surface layers were measured in order to determine the oxygen gradients within the First two meters and to add some informations to the mechanisms of oxygen exchange at the air-sea interface. These investigations may be interesting also with regard to long-term-observations of the oxygen distribution in the Atlantic, especially the problem of the A.O.U. (apparent oxygen utilization) determination. To measure oxygen gradients a special sampler was built which is able to take water samples each 20 cm of the First 2 meters. These data were supplemented by further samples down to 150 m, taken by conventional water samplers, from which samples were also taken to measure N2/02-relations. By comparing these relations with theoretical relations in air-saturated water the influence of biological production and consumption on the oxygen contents in water could be estimated. A simple glass apparatus was built to extract gas from the water samples, and hereafter the N2/02-relations were determined by mass spectrometry. Most distributions of the oxygen anomaly show a negative oxygen balance which varies largely, probably due to strong mixing processes in the Iceland-Färö ridge area. The distribution of surface oxygen saturation values are of two different types. The values of the stations 260, 262 and 270 stem from mixed water and show homogeneous supersaturations, as can be found instantly when whitecaps appear. The values of 9 other stations are from water, sampled during calm periods which has been mixed and supersaturated before. They show a decreasing oxygen saturation towards the sea surface and often undersaturation in the upper decimeters up to 98% and even 91%. So at the air-sea interface even less initial oxygen saturation than 100% can be found after supersaturation during heavy weather periods.

Description: Records of currents and temperature on the upper edge of the continental slope off Sierra Leone show a significant energy peak between 0.3 and 2 cph in the bottom near layer. The fluctuations of temperature and velocity are interpreted as internal waves over a critical bottom slope. Since they seem to receive their energy mainly from the barotropic tide, the phenomenon is of interest in the dissipation cascade of tidal waves. The high frequency current amplitudes are occasionally strong enough to affect sediment deposition and related benthic processes. Inspection of current meter records from other regions of the NW-African continental slope reveal the similar effect of intensified bottom current fluctuations.

Description: This paper presents a compilation of the data sets obtained by CTDs and profiling current meters on board the ships "Meteor" and "Planet" during GATE in the B- and C-Scale Areas (7°-10 °N, 22°-25°W, June 17 to September 24, 1974). The bulk of the CTD data is displayed in the form of isopleths. Selected sets of profiles, outlining special phenomena observed, and profiles of the mean and standard deviation of temperature and salinity are given additionally. Besides examples of actual current profiles, isopleths of the 25 hour mean current components, and isopleths of the vertical shear are presented. The mean current components and their standard deviations are also displayed. Time series presented are suitable for comparison with moored current measurements. The presentation of the data is preceded by a summary of the editing procedures and by a discussion of the data quality.

Description: One main point of our atmospheric-electric measurements over the Atlantic Ocean 1973 was the investigation of the air-earth current density above the sea. In addition to direct measurements at the water surface with a floating net, we calculated the air-earth current density from the electric field and the air conductivity measured simultaneously on board of the ship and during particular ascents in the free atmosphere. During all five ascents the air-earth current density did not change with altitude. For pure maritime air-conditions, the mean air-earth current density was found to be 2.9 pA/m2. The mean hourly air-earth current density over the Atlantic shows nearly the same 24-hour pattern as measured by COBB (1977) at the South Pole at the same time. When dust-loaden air masses of African origin reached the ship as well as under continental influence the mean air-earth current density was reduced to 2.1pA/m2. The global 24-hour pattern was modified by this continental influences. Finally, it is shown that the values of the air conductivity measured on board R. V. "Meteor" during our earlier expeditions have been influenced by the exhaust of the ship and must therefore be corrected. With this correction, our new mean values of the air-earth current density over the Atlantic are 2.6 pA/m2 in 1965 and 2.0 pA/m2 in 1969. From all measurements, the global air-earth current is estimated to be about 1250 A.

Description: The fluxes of momentum, heat, and water vapour have been obtained by the aerodynamic profile method. Within the frame work of GATE variation of fluxes with disturbed conditions are of special interest. The time traces of surface layer parameters repeatedly showed definite instationarities marked by a sudden drop of temperature by a few degrees centigrade. For these pronounced instationarities, equilibrium state of the profiles was regained after a few minutes, in agreement with scale considerations. For fluxes properly nondimensionalized in terms of surface layer parameters, no systematic deviations have been found under disturbed conditions compared with undisturbed conditions. Due to systematic variations of parameters, the energy exchange between sea and atmosphere was enhanced by about 30 % under disturbed conditions. From the above evidence it is concluded that for larger scale investigations reliable determination of fluxes from surface layer mean variables is possible.

Description: The Aitken particle size distribution in background aerosols was measured with a newly developed Diffusion Analyzer System. The measuring system and the inversion method is discussed critically. The several hundreds of measurements indicate that several maxima in the size distribution are present. Particles as small as 10-3 µm in radius are constantly observed. Measurements of other authors indicate similar results.

Description: Size distributions of Aitken nuclei were measured in the middle and western part of the North Atlantic between 38 through 22° N and 36 through 63° W. The apparatus comprised diffusion batteries and an especially designed condensation nuclei counter. The measurements cover the size range from about 3·10-1 through to 1·10-5 cm aerodynamically equivalent particle radius. There are some indications on the trend of particle numbers above 1·10-5 cm but no reliable number distributions. The size spectra were bimodal in the north eastern part of the cruise. Closer to the Caribbean the contribution of very small particles was enhanced and the peaks shifted to larger sizes to a certain extent.

Description: On board of the German research vessels "Meteor" and "Anton Dohrn" the components of shortwave and longwave radiation budgets have been measured over the Fladenground area during a short period in 1975 (13.-19. August) and the Fladenground-Experiment (FLEX, 25 March 1976-13 June 1976). The data show that in spring and in the beginning of summer, when the ocean water is still cool, the daily incident solar radiation exceeds the net thermal radiation loss of the water to the atmosphere. In August, however, the water emission has increased to such a level that on disturbed days the daily mean radiation balance is negative. The monthly averages of the radiation budget and the global radiation derived from the shipborn measurements agree surprisingly well with those derived by several authors from climatological data. A simple scheme has been developed to parameterize the global radiation with respect to the observed cloudiness.

Description: The Th content of the sediment samples from "Meteor" core 12310 (3080 m water depth, off NW Africa) on a carbonate-free basis lies around the average of 12.4 ppm and is similar to the average content of the earth crust. On the contrary, uranium was found to be up to 3.5-fold enriched in the core section between 60 and 330 cm (within the Würm Glacial) where reducing conditions occur, due to deposition of authigenic uranium (9 µg/cm2 1000 yrs.). The authigenic uranium content is correlated to the organic matter content (U/Corg ratio = 6 · 10-4). On the basis of the uranium content of the oxidized section uranium was split into a detritic and an authigenic component and the amount of supported ionium was calculated. From the profile of the specific I0.excess act1v1ty Io-total - Io-supported) with depth, average sedimentation rates of 3.3 ± 0.6 cm/1000 yrs. for the warmer stages and of 5 ± 1 cm/1000 yrs. for the cooler periods were estimated.

Description: A rapid procedure for Io (Th230) dating of sediments with accumulation rates in the range of several cm/1000 years is described. Studying of large sample populations with very small Io-excess activity is possible as the counting time (around 1500 min/sample) are 2 to 5 times shorter than with the standard Io-excess method. Improved sensitivity of the Io-excess measurement is achieved by: 1) extraction (~90%) of the authigenic Io-excess with EDTA, with minor leaching (~30%) of the allogenic Th232 and Io-supported, 2) processing samples as large as 10 g or more. The procedure was applied to sediments from the Caribbean (V 12-122) and from the Ionian Sea (22M48 and 17M17). In the case of the standard core V 12-122 our results are in good agreement with previous time-consuming Io determinations. The resulting average accumulation rates of 2.0 ± 0.3 cm/1000 years for the Ionian Sea cores are close to the average derived from magnetic reversal studies of a nearby core.

Description: A preliminary study was carried out on the ostracode fauna obtained from marine sediments off the Sahara Desert. The ostracodes are divided into two distinct associations: Association A - shallow water (100-483 m); Association B - deep water (470-2859 m). The deep water association differs from that of the shallow water by its low diversity and by the predominance of somewhat larger "blind" ostracodes in it. The depth of the boundary between the two associations corresponds closely to the general universally recognized 500 m boundary, below which psychrospheric conditions prevail and dictate the appearance of typical deepwater ostracode fauna.

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).