ALBERT

Description: In Moreton Bay, Queensland, the catch obtained using monofilament polyamide (PA) otter trawl-nets with multifilament polyethylene (PE) cod ends was compared with that obtained using multifilament PE trawl-nets of identical mesh opening (38 mm). Monofilament PA otter trawl-nets retained fewer small prawns ( 〈 24 mm carapace length) than conventional multifilament PE nets, but both nets caught similar quantities of larger prawns ( 〉 24 mm carapace length). The higher retention rate of small prawns by multifilament PE gear was reflected in the greater catch weights of Peraeus plebejus, Metapenaeus bennettae and Metapenaeopsis novaeguineae in those nets. Catch weights of larger prawn species such as Penaeus esculentus and Metapenaeus endeavouri did not differ between nets. Winter whiting (Sillago maculata) and squid (Loligo spp.) were trawled in similar abundance in both nets, although the monofilament retained fewer squid 〈 50 mm mantle length. More marketable ( 〉 15 cm carapace width) sand crabs (Portunus pelagicus) were caught in the monofilament net. There was not significant difference in the trash (noncommercial component) weight caught in both nets. Over the range of towing speeds tested (1.7–2.3 kn), use of monofilament nets significantly reduced total gear drag.

Description: RECENT advances in 40Ar/39Ar dating1,2 have made it possible to date individual K-feldspar grains from Pleistocene tephra, a capability that greatly improves the reliability and temporal resolving power of the method. Here we apply these new techniques to the dating of a phonolite tephra from the East Eifel volcanic field in West Germany, which is sandwiched between loess and palaeosol (alfisol) deposits, and which was therefore erupted during the transition from a glacial to an interglacial period. Our age estimate for this transition is 215±4 kyr (1 σ), which has important implications for the marine δ18O timescale and for models of global climate change during the Pleistocene. The results show that single-grain dating can detect and compensate for the large quantities of xenocrystic contaminants which are found in many tephra deposits. This technique could be used to date the tephra layers found in marine sediment cores and the results could greatly enhance the reliability of the marine δ18O timescale for more rigorous Fourier analysis testing of the Milankovitch hypothesis.

Description: Sediments on high Arctic shelves result from modern processes and the effect of former glaciations. Based on data from the northern Barents Sea, an area with input from large and numerous surging glaciers, we define two principal zones with different environmental regimes and corresponding sedimentary facies: (1) a glacier-proximal zone influenced by grounding-line processes and the immediately adjacent areas affected by glacial sediment input, and (2) a glacier-distal, sea-ice and current-controlled zone, which also includes a wide sediment-starved region dominated by biogenic carbonate accumulation. Characteristic of the glacier-proximal zone are glacial surges which affect sedimentation rates and leave a diagnostic pattern of sea-floor morphologies. Extensive ice gouging causes a homogeneous sediment texture. In the glacier-distal zone, fine-grained mud supplied from sea ice and infrequent coarser material deposited from icebergs is reworked by modern oceanographic processes. On shallow banks, in 30–50 m of water, carbonates accumulate from a prolific bottom fauna formed in response to extensive reworking and nutrient supply.

Description: Marine geophysical surveys employing Seabeam, multi- and single-channel seismic reflection, gravity and magnetic instruments were conducted at two locations along the continental slope of the Peru Trench during the Seaperc cruise of the R/V “Jean Charcot” in July 1986. These areas are centered around 5°30′S and 9°30′S off the coastal towns of Paita and Chimbote respectively. These data indicate that (1) the continental slope off Peru consists of three distinct morpho-structural domains (from west to east are the lower, middle and upper slopes) instead of just two as previously reported; (2) the middle slope has the characteristics of a zone of tectonic collapse at the front of a gently flexured upper slope; (3) the upper half of the lower slope appears to represent the product of mass wasting; (4) thrusting at the foot of the margin produces a continuous morphologic feature representing a deformation front where the products of mass-wasting are overprinted by a compressional tectonic fabric; (5) a change in the tectonic regime from tensional to compressional occurs at the mid-slope-lower slope boundary, the accretionary prism being restricted to the very base of the lower slope in the Paita area. The Andean margin off Peru is an “extensional active margin” or a “collapsing active margin” developing a subordinated accretionary complex induced by massive collapse of the middle slope area.

Description: Clay- and silt-size mineral assemblages are described from eight piston cores from the fiords and shelf on the western margin of Baffin Bay, Arctic Canada. Radiocarbon dates indicate that all the cores extend back in time to the last local glacial/interglacial transition (i.e. 8–10 ka); four extend back to between 10 and 12 ka, and HU77-021-156, located on the Southeast Baffin Island shelf, includes the entire late Foxe glacial stage. Silt- and clay-size particles constitute ca 40 and 55%, respectively, by weight of the bulk sediment. The clay-size fraction is dominated by mica; feldspars and quartz are the main constituents of the silt fraction. The fiord sediments are mainly composed of local mineralogies, but on the shelf, and at times in the fiords, exotic mineral species occur. The most important of these are detrital carbonates, derived from erosion of the Paleozoic basins in Arctic Canada and/or northwest Greenland. Both calcite and dolomite occur; calcite is the major carbonate mineral in the “southern” cores, whereas dolomite is the most abundant in cores north of 66°N. Higher inputs of carbonate species occur during regional deglaciation, 7–10 ka, and during the last 5 ka (probably reflecting increased iceberg production from northwest Greenland). Thus variations in the precentages of the carbonate minerals indicate significant shifts in Late Quaternary glacial-sediment source areas and oceanographic regimes.

Description: Changes in composition of modern benthic ostracod faunas across the continental margin of southwestern Africa occur at boundaries between and within major water masses: a Mixed Layer-Antarctic Intermediate Water (AAIW) boundary at 200 m, an AAIW salinity minimum zone at 650 m, an AAIW bathyal thermocline at 1000 m, and the AAIW/North Atlantic Deep Water (NADW) boundary at 1500 m. In addition, two population changes occur within the NADW at 1.8–2.0 km and 2.0–3.0 km. The Antarctic Bottom Water assemblage is sparse and poorly preserved.

Description: In ecological studies, especially in those dealing with energy circulation in nature, determinations of the energy content of organisms are inevitable. Energy determinations are, however, laborious and time-consuming. Average conversion factors based on different species form various areas and seasons may often be a shortcut for overcoming this problem. To establish general energy conversion factors for aquatic invertebrate groups, we used 376 values of J · mg−1 DW and 255 values of J · mg−1 AFDW, representing 308 and 229 species, respectively. The dry-weight-to-energy factors were highly variable both within and between taxonomic groups, e.g.: Porifera, 6.1 J · mg−1 DW; insect larvae, 22.4 J · mg−1 DW (median values). The energy-conversion factors related to AFDW showed a much smaller dispersion with a minimum median value of 19.7 J · mg−1 AFDW (Ascidiacea) and a maximum of 23.8 J · mg−1 AFDW (insect larvae). Within taxonomic groups, the 95% confidence intervals (AFDW) were only a few percent of the median values. The use of energy-conversion factors based on AFDW is preferable due to their lower dispersion. For aquatic macrobenthic invertebrates, a general conversion factor of 23 J · mg−1 AFDW can be used.

Description: Paleoceanographic and stratigraphic methods, based on high-resolution compressional wave (p-wave) velocity measurements, have been applied to the studies of late Quaternary deep-sea carbonates in the western and eastern equatorial Atlantic. The measurements provide sonostratigraphic records in which changes in p-wave velocity parallel the changes from a glacial to an interglacial climate: Maxima in p-wave velocity (greater than 1540 m/s) occur during interglacial oxygen isotope stages 1, 5 and 7. Minima (1490 m/s) occur during glacial oxygen isotope stages 2, 4 and 6. Changes in p-wave velocity parallel past changes in carbonate accumulation and sediment coarse fraction, and allow a detailed core to core correlation. From these results two main patterns emerge: (1) In cores from shallower than 4300 m and from well above the present lysocline, large temporal changes in p-wave velocity parallel the production of planktonic foraminifera and the climatic history recorded in the sediments, and (2) below 4300 m, the position of the foraminiferal lysocline in the western equatorial Atlantic, large downcore p-wave velocity fluctuations gradually disappear due to dissolution of carbonate sediments. Dissolution also causes a distinct decrease in p-wave velocity and acoustic reflectivity in surface sediments across the present foraminiferal lysocline. Thus, past changes in the position of the foraminiferal lysocline or calcite compensation depth that caused distinct changes in reflectivity of sediments should lead to distinct reflectors within sediment columns. Their distribution can be utilized to map paleowater masses with different degrees of carbonate saturation.

Description: Observations of temperature and electrical conductivity by a recording in situ salinometer are discussed in respect oo the physical processes connected with the renewal of North Atlantic deep water. The measured fine structure of the layering suggests that the downward movement of cooled surface water is combined with horizontal mixing down to more than 1000 m depth. This is confirmed by the existence of water elements which have slightly different temperature and salinity. Curves of temperature, conductivity, and salinity and T-S diagrams are shown.

Description: Measurements in the mixing zone of the Elbe estuary were performed during three consecutive tidal cycles with three types of instruments—a moored tripod with velocity and temperature/conductivity/light attenuation sensors, a profiling sonde with similar sensors lowered from an anchored vessel, and instrumented moorings. Acoustic-travel-time sensors were used for velocity measurements. Spectral analysis of 12·8 min pieces of the obtained time series gives results that are consistent with isotropic turbulence for part of the frequency space. Temporal changes of turbulent kinetic energy are correlated with tidal current velocity. A retardation is found between changes in tidal current and turbulent energy. Not all shear stress terms are in similar phase with tidal flow. Mean gradients, Reynolds stress terms, and turbulent salt flux terms are combined to determine eddy viscosity and eddy diffusion coefficients.

Description: Silica chimneys were discovered in 1985 at 86°W in the rift valley of the Galapagos Spreading Center at 2600 m depth (“Cauliflower Garden”). The inactive chimneys lack any sulfides and consist almost entirely of amorphous silica (up to 96 wt.% SiO2, opal-A); Fe and Mn oxides are minor constituents. Oxygen isotope data show that formation of the silica chimneys took place at temperatures between 32°C (+29.9‰ δ18O) and 42°C (+27.8‰ δ18O).Th/Udating reveals a maximum age of 1440 ± 300y. Amorphous silica solubility relations indicate that the silica chimneys were formed by conductive cooling of pure hydrothermal fluids or by conductive cooling of a fluid/seawater mixture. Assuming equilibrium with quartz at 500 bars, initial fluid temperatures of more than 175°C (i.e., a concentration of 〉 182 ppm SiO2) were required to achieve sufficient supersaturation for the deposition of amorphous silica at 40°C and 260 bars. If the silica chimneys originate from the same or a similar fluid as higher-temperature ( 〈 300°C) sulfide-silica precipitates found nearby (i.e., 2.5 km away), then subsurface deposition of sulfides may have occurred.

Description: ROOTH proposed that the Younger Dryas cold episode, which chilled the North Atlantic region from 11,000 to 10,000 yr BP, was initiated by a diversion of meltwater from the Mississippi drainage to the St Lawrence drainage system. The link between these events is postulated to be a turnoff, during the Younger Dryas cold episode, of the North Atlantic's conveyor-belt circulation system which currently supplies an enormous amount of heat to the atmosphere over the North Atlantic region2. This turnoff is attributed to a reduction in surface-water salinity, and hence also in density, of the waters in the region where North Atlantic Deep Water (NADW) now forms. Here we present oxygen isotope and accelerator radiocarbon measurements on planktonic foraminifera from Orca Basin core EN32-PC4 which reveal a significant reduction in meltwater flow through the Mississippi River to the Gulf of Mexico from about 11,200 to 10,000 radiocarbon years ago. This finding is consistent with the record for Lake Agassiz which indicates that the meltwater from the southwestern margin of the Laurentide Ice Sheet was diverted to the northern Atlantic Ocean through the St Lawrence valley during the interval from ~11,000 to 10,000 years before present (yr BP).

Description: Abrupt changes in climatic conditions have been seen at high latitudes in the North Atlantic and the Antarctic at 13 kyr BP. It is important to determine whether this abrupt change was confined to high-latitude regions or whether it was global. Here we present results demonstrating an abrupt change in the rate and character of sedimentation in the South China Sea at the close of the last glacial period. Radiocarbon dating and its position in the oxygen isotope shift suggest that this change may be coincident with the changes found at high latitudes.

Description: Abrupt changes in climatic conditions have been seen at high latitudes in the North Atlantic1 and the Antarctic2,3 at 13 kyr BP. It is important to determine whether this abrupt change was confined to high-latitude regions or whether it was global. Here we present results demonstrating an abrupt change in the rate and character of sedimentation in the South China Sea at the close of the last glacial period. Radiocarbon dating and its position in the oxygen isotope shift suggest that this change may be coincident with the changes found at high latitudes.

Description: The release of exchangeable Mg in marine sediments from displacement by ammonium ions was estimated by way of experimentally determining the parameters that govern this ion-exchange equilibrium on solid geochemical phases: smectite, humic acid, illite and opal. We showed that: (a) both the conditional selectivity constant as well as the solid concentration are important parameters in determining the relative contribution of ammonium-exchangeable Mg from smectite, organic matter, illite and opal; and (b) that, except in the cases where opal or organic matter concentrations are very high, the clays are the dominant carrier phases for labile Mg which is exchangeable by ammonium. A model, based on the sum of the contributions from the major geochemical phases present in the sediment reliably predicts the amount of Mg released by exchange with ammonium in marine sediments.

Description: A radiotracer technique, employing 27Mg, is used to determine the Mg released by ammonium exchange on undis-solved humic acid in a seawater medium. This new method allows for the measurement of exchangeable Mg on the solid phase surface, which eliminates the problem caused by the high-Mg background in the seawater matrix. The precision calculated from the counting statistics is better than ±2%; the reproducibility among repeated counts ranged from ±1% to ±3%. The higher sensitivity of the method allows for monitoring the MgNH4 exchange at concentrations as low as 30 mM NH4. This is a major improvement relative to the data obtained with the analytical methods used so far, which allow detection of exchangeable Mg only at NH4 concentrations higher than 1 M. The lower experimental concentrations are more in accordance with the natural ammonium levels found in anoxic marine sediments. For the undissolved humic acid used in this experiment, the amount of exchangeable Mg in apparent equilibrium with an ammonium-free seawater matrix was found to be 96.6 ± 0.4 meq/100g. The Mg-NH4 exchange on humic acid in seawater comes to a steady-state value in 〈 18 min. The conditional equilibrium constant obtained for this reaction, Kcond = 0.039 ± 0.001 M−1. The technique can be expanded to other geochemical solid phases in seawater and it can be modified to study the behavior of the major cations by using 24Na, 42K and 49Ca.

Description: Compressional-wave (P-wave) velocities and magnetic susceptibilities were measured on gravity (GGC) and piston cores (PC) and Ocean Drilling Program (ODP) Leg 108 advanced piston cores (APC) from the equatorial Atlantic to test our hypothesis that climatically driven changes in terrigenous and biogenic fluxes, and in carbonate dissolution control the interrelationships between the two signals. In Pleistocene sediments deposited above the calcium compensation depth (CCD) we observed changes in P-wave velocity and magnetic susceptibility that are (1) inversely correlated, and (2) coherent to changes in glacial-interglacial climate. Glacials show low P-wave velocities and relatively high magnetic susceptibilities. In contrast, interglacials show high P-wave velocities and relatively low magnetic susceptibilities. These temporal changes in P-wave velocity and magnetic susceptibility reflect the climatic history recorded in the sediments and are related to: (1) the production of biogenic carbonate, mainly planktonic foraminifera, and (2) the terrigenous sediment supply that contains magnetic minerals. Below the CCD this pattern disappears and consistently low P-wave velocities and distinctly higher magnetic susceptibilities prevail. The distinct decrease of large P-wave velocity fluctuations is due to the dissolution of carbonate sediments which cause a distinct decrease in sand grain sizes and a consistently low carbonate content (〈 10%). Dilution of magnetic material by the carbonate fraction is minor and the high magnetic susceptibility values and the relatively high amplitude variations in magnetic susceptibility are due to changes in the magnetic mineral concentration of the terrigenous (non-carbonate) fraction. In early Pliocene sediments we also observed covarying velocity and magnetic susceptibility signals that may reflect a predominatly terrigenous control on sedimentation. Our preliminary results demonstrate that a combined use of non-destructive measurements of acoustic and rock-magnetic signals provides a potential paleoceanographic tool for characterizing: (1) glacial-interglacial pelagic sedimentation, (2) pelagic sedimentation above the CCD, (3) increases in carbonate dissolution, and (4) areas below the CCD. Furthermore, rock magnetic fluctuations in sediments below the CCD may provide an important stratigraphic tool for the deep carbonate-free basins of the world's oceans.

Description: Perhaps the most significant event in the Cretaceous record of the carbon isotope composition of carbonate1,2, other than the 1–2.5 ‰ negative shift in the carbon isotope composition of calcareous plankton at the Cretaceous/Tertiary boundary3, is the rapid global positive excursion of ~2 ‰ (13C enrichment) which took place between ~91.5 Myr and 90.3 Myr (late Cenomanian to earliest Turonian (C/T boundary event))1,4,5. This excursion has been attributed to a change in the isotope composition of the marine total dissolved carbon (TDC) reservoir resulting from an increase in rate of burial of 13C-depleted organic carbon, which coincided with a major global rise in sea level5 during the so-called C/T oceanic anoxic event (OAE)6. Here we present new data, from nine localities, which demonstrate that a positive excursion in the carbon isotope composition of organic carbon at or near the C/T boundary7,8 is nearly synchronous with that for carbonate and is widespread throughout the Tethys and Atlantic basins (Fig. 1), as well as in more high-latitude epicontinental seas. The postulated increase in the rate of burial of organic carbon may have had a significant effect on CO2 and O2 concentrations in the oceans and atmosphere, and consequent effects on global climate and sedimentary facies.

Description: Sharp jumps in climate punctuate the records from borings in the Greenland ice cap during the time interval 60,000 to about 20,000 yr ago. Rapid fluctuations are also seen in foraminifera records for cores from the northern Atlantic and in a pollen record from a core from a bog in the Vosges Mountains in France. In this paper we present a new radiocarbon chronology for northern Atlantic deep-sea core V23-81 which permits comparison with the radiocarbon-dated Vosges Mountains pollen record. Because of the lack of a 14C chronology for the Greenland ice record and of distortions peculiar to each of the three records, it is not yet possible to say whether or not the events are genetically related.

Description: The life cycle of loliginid squids has been completed in recirculating seawater systems. Two systems were required: a 2 m diameter circular culture tank (CT) with adjoining 2 m circular filter tank (3000 liters total volume of natural seawater) for culture of hatchlings, 1–60 days old; and a 6 × 2·6 × 1 m raceway culture tank (RW) with a smaller adjoining rectangular filter tank (14 850 liters total volume of artificial seawater) for the grow-out of adults. Both systems were equipped with temperature control apparatus, modular filter units (particle filters and activated carbon), foam fractionators, biological filters (crushed oyster shell) and UV sterilizers. The systems carried low bioloads, 〈 1·0 g/m3 and as high as 0·8 kg/m3, respectively. Water quality was excellent: NH4N was below 0·01 mg/liter in the CT and 0·10 mg/liter in the RW: NO2N was below 0·01 mg/liter in the CT and 0·03 mg/liter in the RW; NO3N was below 12 mg/liter in the CT and below 50 mg/liter in the RW; and pH was above 8·0 in both systems. The design of the systems proved to be behaviorally and physiologically suitable for squids and two species grew to adult size and produced viable young. These systems are compared to other squid maintenance and rearing systems and marine recirculating seawater systems.

Description: Reviews the major deep-sea expeditions from that of HMS Challenger in 1873 to 1960. Emphasis is on the increasing sophistication of vessels and equipment used, the growth of international cooperation and the proliferation of branches of oceanographic studies. Arctic work by Nansen, Sverdrup, recent Soviet scientists, the Scripps Institution and the Norpac program are mentioned (maps). Vessels used during the period and their activities are tabulated. Two maps show cruises of the Atlantic Polar Front Program Jan-Dec 1958 in the Greenland and Barents Seas

Description: A comparative study of isodideimnine-1 and didemnin B is presented using spcctroecopic methods, partial degradation and partial synthesis. This leads to the conclusion of the presence of a single depsipeptide, namely didemnin B, with (3S,4R,5S) isostatine instead of the previous statine residue. An attempt to determine the whole conformation in solution of didemnin B by using 2D-NMR is also described.

Description: Seismic refraction investigations along a 440-km long profije on the northern Baltic Shield have resolved the crustal structure in this area of Archaean to Early Proterozoic lithosphere formation. The profile, called the POLAR Profile, extends approximately along a SW-NE-oriented line from the Karelian Province in northern Finland across the Lapland Granulite Belt and the Kola Peninsula Province to the Varanger Peninsula in northeastern Norway. At six shotpoints, large explosions (200–1680 kg), and at three shotpoints, small explosions (80 kg) were detonated and recorded at an average station spacing of 2 km, providing high-quality record sections. A two-dimensional cross section of the crust was obtained by forward modelling using ray-tracing techniques. High-velocity bodies are found in the upper crust related to the Karasjok-Kittilä Greenstone Belt and the Lapland Granulite Belt. They extend to a depth of 6–13 km. In the Karelian Province in the southwest, a low-velocity zone was found between the depths of 8 and 14 km. The middle crust shows a slight increase in the average velocities from the southwest to the northeast, and a small velocity jump is found along a mid-crustal boundary between 18 and 21 km. The thickness of the middle crust varies between 16 and 18 km. The lower crust and the crust-mantle boundary (Moho) show considerable lateral variation. The top of the lower crust lies between 26 and 33 km, while its thickness decreases from 21 km in the southwest to 10–14 km beneath the Lapland Granulite Belt and the Inari Terrain, reaching 20 km again in the extreme northeast. The velocities also change laterally. The thin lower crust is characterized by rather low velocities (6.8–6.9 km/s), whereas in the southwest and northeast the velocities (6.9–7.3 km/s) resemble more typical shield structures. The Moho is found at 47 km in the Karelian Province, rises to 40 km beneath the Lapland Granulite Belt and descends to 46 km in the northeastern part of the Kola Peninsula Province. The upper mantle velocities at the Moho range from 8.1 km/s in the region of the thin crust, to 8.5 km/s and more beneath the Karelian Province. It is tempting to suggest that the anomalous lower crust underlying the Lapland Granulite Belt and the Inari Terrain may represent the remnants of an Early Proterozoic back-arc basin that was active prior to the 2.0 to 1.9 Ga plate convergence event, during which the Lapland Granulite Belt was thrust onto the Archaean basement of the Karelian Province. Another explanation is to assume that the velocity reduction in the anomalous lower crust was caused by a rather pronounced uplift of this region following the 1.9-Ga collision event.

Description: Pore fluid venting associated with subduction-induced sediment deformation causes precipitation of calcium carbonate as prominent carbonate chimneys or cement in the accreted sediments across the active continental margin off Oregon and Washington. A depletion of interstitial Ca2+ with a maximum decrease of 50% relative to seawater Ca2+ over only 1.5m depth and reduction in porosity in the deformed sediments suggest that interstitial Ca2+ is removed to form calcium carbonate cement. In contrast, the pore waters of the undeformed abyssal plain sediments show no depletion in dissolved Ca2+. They are either enriched to a maximum of 5% or show no change in dissolved Ca2+. Here the background level of CaCO3 content in the sediment is only 0.1 to 1%. Calcium carbonate precipitation in the deformed sediments probably occurs as the result of upward migration and oxidation of biogenic methane and of the increase in carbonate saturation due to release of excess pore pressure during fluid venting. Upward advection of fluids at rates of 1–28 cm y−1 is predicted from diffusion-advection-reaction models applied to the downcore concentration profiles of dissolved Ca2+ and NH4+ in the tectonically-deformed sediments. The range of predicted flow rates is related to the type of calcium carbonate lithification; i.e. slow rates generate cement and fast rates generate chimneys. Carbonate mineral precipitation associated with pore fluid venting requires direct transfer of Ca2+ from the oceanic basement to the accretionary complex. Such a mechanism leads us to propose that the accretionary complexes of the global plate subduction zones are a major sink for crustal Ca2+. A global flux of crustal Ca2+ that is removed by carbonate mineral precipitation may be as muc3 as the hydrothermal Ca-input. This significant Ca-flux, not previously considered in the global geochemical budget, implies that pore fluid venting in subduction zones may also act as a global sink or source for other elements.

Description: Ocean crustal carbon uptake during seafloor alteration at DSDP Sites 417A, 417D, and 418A exceeds the estimated loss of carbon during magmatic ridge outgassing. If these sites are representative for oceanic crust in general, 2.2–2.9 × 1012 moles of carbon are removed from the oceans per year as a net flux of carbon between the oceanic crust and seawater. Although most of this carbon occurs as calcium carbonate, this ocean crustal carbonate probably cannot be considered part of the marine calcium carbonate sink since much of the Ca in these carbonates must be derived from basalt alteration that is not balanced by a concomitant uptake of seawater Mg. Our present estimate cannot be satisfactorily applied to global carbon budgets, because of uncertainties in the bulk budget of ocean floor alteration and because of the uniqueness of our estimate. Yet, our data document that the formation of ocean crust provides a significant sink for carbon that should be included in models of the global cycling of carbon. Furthermore, magmatic outgassing during ocean crust emplacement and seafloor basalt alteration may provide a buffering mechanism for atmospheric carbon.

Description: The imaging of a multichannel seismic record was improved by reprocessing using pre-stack techniques. The reprocessed record shows structures that indicate tectonic erosion and gravity collapse at the front of the Japan Trench margin. Much of the lower slope appears to be underlain by a detached, coherent block of continental crust. The lower slope has failed by mass wasting and the resulting apron of slump debris at the base of the slope has become involved in thrust faulting at the front of the subduction zone. Slumping continues as long as debris is removed from the front of the margin by subduction, and the apron cannot build up sufficiently to stabilize the failing lower slope. Truncated beds at the base of the upper plate indicate subcrustal erosion as well, this probably being the main cause of massive subsidence of the margin. Subsidence was the cause of oversteepening, destabilization and subsequent gravity collapse of the leading edge of the upper plate.

Description: The ice-proximal environment of the Nordaustlandet tidewater ice cap, Svalbard Archipelago, is one of the best analogues for understanding glacial geologic processes of northern continental shelves during initial Pleistocene deglaciation. Investigations of the proglacial region in 1980–1983 showed that the sedimentary environment is dominated by numerous meltwater outflows which discharge sediment-laden water from subglacial meltwater streams during the summer. Two large, stable meltwater outflows were observed in embayments along the southern part of the ice front. Landsat images show that both outflows have been in approximately the same position since at least 1976. They are located at the intersection of glacial drainage basins and centered over depressions in the underlying bedrock. An “outflow valley” extending away from the ice front was observed in front of the western meltwater outflow. Sidescan sonar profiling along the glacier front showed a 200 m wide gap in acoustic reflection at the base of the western meltwater outflow, probably caused by meltwater effluence. Enhanced sediment accumulations in this region, observed as a ≈ 3 ms sediment drape in front of the outflow, and large arcuate ridges in the outflow valley, testify to the transport efficiency of the subglacial meltwater stream. Several mounds, up to about 25 m high and 200 m wide, are observed on sidescan and 3.5 kHz profiles directly in front of the outflow. Although samples from these structures are absent, they are most likely composed of sediment and are similar to beaded eskers observed in Pleistocene glacimarine sequences indicating locally very high sedimentation rates. Fine-grained components of the subglacial discharge incorporated in the buoyant meltwater plume are usually entrained in a westerly coastal current. Elevated suspended particulate material concentrations are observed within the coastal waters in a region extending about 15 km perpendicular to the glacier front and at least 60 km along the ice front extending into the northwestern Barents Sea.

Description: This chapter throws the attention on the methods of sampling the benthos, which has been directed mainly to the operation of the gear at sea and to such other factors as may influence sampling methods. This chapter briefly traces the history of benthos investigations, and then considers how far the instruments now available provide with the quantitative samples. It also shows how advances in other fields, such as radio-position finding, sonar and electronic equipment have increased the precision of our sampling methods. Moreover, sorting and sieving on board ship can be considered and brief mention made of methods of soil analysis and biomass determination. This chapter discusses the two possible approaches for the development of satisfactory quantitative collecting methods. First the improvement of the grab-type of instrument, with particular reference to increasing penetration and the perfection of release gear for the open sea, and second; the development of a wide-core sampler, like the Knudsen sampler, which works satisfactorily in the open sea. Moreover, statistics need to be even more fully applied, where collecting methods justify them, to such problems as the degree and scale of dispersion of individuals.

Description: Cephalopods are exclusively marine molluscs and should be included among the organisms that are of general interest to marine biologists. As to experimental embryology, Naef has already stressed the suitability of cephalopod embryos for experimental work. The whole body of information accumulated in this field during the past half century since Naef published his monograph was reviewed by Marthy. This field of research is clearly underrated by many developmental biologists who could profit by the topological simplicity of the blastulation pattern in cephalopods, which contrasts with the spiralian mode of other molluscs. Questions raised by comparative/evolutionary embryology, following the tradition of descriptive developmental morphology, are truly stimulating to the field of experimental embryology, and vice versa. However, experimental studies are generally possible with only a limited number of models, which, in the case of cephalopods, appear to be embryos of medium to small size. On the other hand, some of the most intriguing questions in cephalopod biology are related to those forms that produce eggs of extremely large size. This chapter gives a brief overview of these recent studies placing them in the chronological sequence of embryogenesis. Studies covering early stages of embryonic development as well as later ones will be cited at least once in the section dealing with the earliest stage considered. Most of these investigations ultimately rest on the basic work by Naef.

Description: Age and growth were estimated on two brood stocks of a loliginid squid, Photololigo edulis (Hoyle), by examining growth increments within the statoliths from 773 specimens. Samples were collected from the northwestern coast of Kyushu, Japan, and the southwestern coast of the Sea of Japan between January 1983 and June 1984. Length and age data were fitted to logistic growth curves for each sex and brood, under the assumption that increments formed daily. Relationships between age and mantle length and the modelled growth curves showed that: the posthatch life span may be 〈 1 yr; growth rates vary considerably between individuals, especially in the second half of life; the average growth rate of the male was higher than that of the female in the warm-season brood, but almost the same in the cold-season brood. Because of the wide variation in the individual growth rate, it was presumed that warm- and cold-season broods were not genetically discrete populations.

Description: Sediment fluxes were highest in the Norwegian Sea during late glacial/early deglacial periods, i.e., at oxygen isotope transition 43, below transition 65, at various levels within stage 6, and below stage 9. Dark diamictons deposited at these times reflect intense iceberg rafting in surface waters fed by surges along the front of the marine-based parts of the continental ice sheets in the southeastern sector of the Norwegian Sea. The high organic carbon content (0.5–1.3%) in these layers reflects input from erosion of terrigenious matter-rich sediments outcropping on the shelves. Partial oxidation of organic matter and decreased deep-water renewal may explain the strong carbonate dissolution observed during these periods. Interglacial environments were strongly variable throughout the last 350 ka. Circulation patterns of stage 5e best resemble modern conditions, while stage 7 and 9 sediments record a much weaker Norwegian Current.

Description: 19 samples (1189 individuals) of the commercially fished Patagonian squid Loligo gahi d'Orbigny were collected from Falkland waters between March 1987 and April 1988 and subjected to starch gel electrophoresis. 41 enzyme-coding loci were screened for polymorphism. Clearly resolved enzyme phenotypes were obtained at 21 loci of which six exhibited polymorphism (glutamate oxaloacetate transaminase, GOT-II, E.C. 2.6.1.1.; α-glycerophosphate dehydrogenase, α-GPDH, E.G. 1.1.1.8; isocitrate dehydrogenase, ICD, E.C. 1.1.1.42; malate dehydrogenase, MDH-II, E.G. 1.1.1.37; phosphogluconate dehydrogenase, PGD, E.C. 1.1.1.44; and phosphoglucose mutase, PGM, E.G. 2.7.5.1). Routine scoring at the 21 loci revealed moderate levels of genetic variability, with the proportion of polymorphic loci, P = 0.273, mean heterozygosities per locus = 0.0693, and the effective number of alleles, Ne, with values of 1.13–1.83.

Description: Genetic population structure of the commercially fished Patagonian squid Loligo gahi d'Orbigny was examined by collecting 19 samples (1189 individuals) from Falkland waters between March 1987 and April 1988 and subjecting individuals to electrophoretic and morphometric analysis. Morphological features (dorsal mantle length, fin length oblique, fin width, interorbital width, tentacle length, length of arms I and II, and mid-mantle circumference), sex and stage of reproductive maturity (Lipinski's universal scale) were recorded prior to electrophoresis. Analyses of allele frequencies at six polymorphic loci provided no evidence of stock separation, and the frequency distribution of genotypic classes almost exclusively fitted Hardy-Weinberg expectations for a randomly interbreeding population. Nei's mean genetic distances and identities between samples ranged from 0.000–0.002 and 0.997–1.00, respectively, supporting the contention of a genetically homogeneous breeding unit. Multivariate analyses revealed significant differences in the morphometrics among certain samples collected at approximately the same time, especially of interorbital width, first arm length and fin width. This morphological differentiation was not correlated with differences at the genetic level. The frequency distribution of dorsal mantle length and stages of reproductive maturity through the year were compatible with two alternative interpretations of population structure: (i) the existence of two temporally distinct separate spawning populations, one autumn- and the other spring-spawning, or, (ii) that slow-growing or late spawned individuals spawn at 18 months old while most squid spawn at 1 yr old in the austral spring and summer. Although it is not possible to discount either interpretation unequivocally, the latter hypothesis of population structure is more congruent with existing genetic evidence.

Description: Pore fluids extracted from near-surface sediments of the deformation front along the Oregon subduction zone have, in general, the dissolved nutrient pattern characteristic of bacterial sulfate reduction. However, in certain locations there are peculiar ammonium distributions and anomalously 13C-depleted dissolved ΣCO2. These carbon isotope and nutrient patterns are attributed to the concurrent microbially-mediated oxidation of sedimentary organic matter (POC) and methane (CH4) originating from depth. In contrast to the oxidation of sedimentary organic matter in the sulfate zone, utilization of methane as the carbon source by sulfate-reducing bacteria would generate only half as much total carbon dioxide for each mole of sulfate consumed and would not generate any dissolved ammonium. The isotopically light ΣCO2 released from methane oxidation depletes the total metabolic carbon dioxide pool. Therefore, NH4+, ΣCO2 and δ13C of interstitial carbon dioxide in these pore fluids distintcly reflect the combined contributions of each of the two carbon substrates undergoing mineralization; i.e. methane and sedimentary organic matter. By appropriately partitioning the nutrient and substrate relationships, we calculate that in the area of the marginal ridge of the Oregon subduction zone as much as 30% of the ΣCO2 in pore fluids may result from methane oxidation. The calculation also predicts that the carbon isotope signature of the carbon dioxide derived from methane is between −35‰ and −63‰ PDB. Such an isotopically light gas generated from within the accretionary complex could be the residue of a biogenic methane pool. Fluid advection is required to carry such methane from depth to the present near-surface sediments. This mechanism is consistent with large-scale, tectonically-induced fluid transport envisioned for accreted sediments of the world's convergent plate boundaries.

Description: Fecal excretion of calcium of endogenous origin has been measured in 52 studies in 33 adult human subjects, under full metabolic balance conditions. Endogenous fecal calcium averaged .130 ± .047 Gm. per day, was positively correlated with both fecal calcium and dietary calcium and was inversely correlated with fractional calcium absorption. The regression line relating endogenous fecal calcium with fractional absorption allowed estimates for total intestinal calcium secretion at both zero and 100 per cent absorption; from these estimates it was calculated that approximately 15 per cent of the total intestinal calcium secretion was nonabsorbable even under conditions when dietary calcium was completely absorbed (presumably because it enters the gut caudad of the absorption sites). Total intestinal calcium secretion, calculated so as to allow for this nonabsorbable fraction, averaged .194 ± .073 Gm. per day, and could not be correlated with age, sex, dietary calcium intake, caloric intake, urine calcium, or plasma calcium. A weak correlation with body size (weight, surface area) was observed. The conditions studied were principally disorders of bone, calcium, and parathyroid metabolism, and in most of them total intestinal calcium secretion appeared identical. The sole exception was seen in two studies on a patient with acromegaly, in which total intestinal calcium secretion was over twice the mean value for the remainder of the group.

Description: Es wird ein neuer Bodenwasserschöpfer von 4,2 l Inhalt beschrieben, der zusammen mit einer Probenahme des unmittelbar am Boden befindlichen Wassers eine sichere Temperaturmessung mit Kippthermometern ermöglicht. A new watersampler containing 4,2 1 is described. Together with water sampling of the bottom water a save measurement of the temperature with reversing thermometers is possible.

Description: Auf Grund langfristiger Registrierungen lassen sich die Strömungsverhältnisse an der Golfküste von Neapel als küstenparallele Grundströmung auffassen, der in periodischer oder nichtperiodischer Form Störungen überlagert sind. Es wird versucht, die EKMANSCHE Theorie des nichtstationären Triftstromes - unter Einbeziehung der horizontalen Reibung und einer Grundströmung - auf die küstenparallele Strömung zu erweitern. Im Gegensatz zu EKMAN, der bei einem konstant wirkenden Wind einen periodischen Massentransport erhält, strebt hier der Massentransport aperiodisch einem durch Reibung und Grundströmung bedingten Grenzwert zu. Außerdem erfolgt der Massentransport nicht senkrecht cum sole zur Windrichtung, sondern es ergeben sich in Abhängigkeit von Reibung und Grundstrom Winkel, die kleiner als 90° sind.

Description: Es wird ein neues Gerät beschrieben, mit dem im Gegenstromverfahren Wasser erzeugt wird, das mit wasserdampfgesättigter Luft bei einer wählbaren Temperatur im Gleichgewicht steht. Dieses Wasser dient als Absolutstandard bei der Sauerstoffbestimmung nach der Winklermethode. Die neu ermittelten Sättigungswerte von KLOTS und BENSON werden in einem Temperaturbereich zwischen 15° und 30° bestätigt. Die Standardabweichung des Sauerstoffgehalts von Simultanproben beträgt 0,005 ml 02/l und liegt damit innerhalb der Fehlergrenzen der angewandten chemischen Titrationsmethode. A new apparatus is described for equilibrating water with water vapor saturated air in a conter current system at defined temperatures. This water is taken as an absolute standard for the oxygen determination by the Winkler method. The new saturation values by KLOTS and BENSON could be confirmcd between 15 and 30° C. The standard dcviation of the oxygen content of replicate samples is 0.005 ml O2/l and is within the limits of error of the chemical titration method.

Description: Beschrieben wird ein Bodenberührungsschalter, der an Unterwassermeßgeräten befestigt werden kann und speziell für Geräte mit Frequenzmodulation und Einleiterkabel entwickelt wurde, z. B. die Bathysonde. A bottoming switch is described, which can be fastened to underwater instruments working with frequency modulation and single conductor cable, e.g. the so called Bathysonde.

Description: Es wird eine Methode zur einfachen, schnellen und genauen Bestimmung von Nitrat in Meer- und Trinkwasser beschrieben. Die nitrathaltige Wasserprobe wird unter Zusatz von Ammoniumchlorid und Ammoniak in einem Jones-Reduktor quantitativ zu Nitrit reduziert und das Nitrit photometrisch bestimmt. 0,05 µg-atom Nitrat-Stickstoff im Liter können noch sicher nachgewiesen werden. Die Standardabweichung der Bestimmung liegt bei einem Gehalt von 1,4 µg-atom N03- - N/L bei ∓ 0,016 µg-atom = ∓ 1,2%. Mit 6 Reduktoren können in der Stunde etwa 20 Wasserproben untersucht werden. A simple, rapid and accurate method for the determination of nitrate in sea and drinking water is described. Ammoniumchloride and ammonia solution are added to the water sample containing nitrate. The sample is quantitatively reduced to nitrite in a Jones reductor with cadmium amalgame. The nitrite is determinated photometrically. 0,05 µg-atom nitrate-nitrogen per liter can be detected surely. The standard cleviation at the 1,4 µg-atom level is ∓ 0,016 µg-atom N03--N / L = ∓ 1,2%. With 6 reductors about 20 samples can be analyzed within 1 hour.

Description: Im Ursprungsgebiet der Südäquatorialströmung findet man erhöhte Werte von Seston und Plankton. Die auf einer Fahrt mit H.A.M.S. DIAMANTINA im Juli und August 1961 gefundenen Daten sind für die Oberschicht in den Abb. 2-7 und für ausgewählte Vertikalserien in Abb. 9-13 zusammengestellt. Eine Deutung durch die hydrographischen Verhältnisse wird versucht. Tab. 1 und 2 enthalten Schicht-Mittelwerte für das untersuchte Gebiet. Some results are given from H.A.M.S. DIAMANTINA cruise 3/61 in July-August 1961. The data for the surface layer are presented in fig. 2-7, for selected casts in fig. 9-13, the values for definite levels are summarized in tables 1 and 2. Seston and microbiomass content is increased under the influence of the South Equatorial Current, and in shallow waters.

Description: Es werden Versuche mit zwei verschiedenartig aufgebauten Konzentrationszellen beschrieben, deren EMK auf Grund der Verwendung von Silber/Silberchlorid-Elektroden von der Chloridkonzentration im Elektrolyten abhängt. Die Arbeitsweise von Zellen mit Polyäthylen- und mit Ionenaustauschmembranen wird durch Meßreihen mit reinen NaCI-Lösungen und mit Seewasser verglichen. Es wird eine potentiometrische in-situ Anordnung beschrieben und ein Beispiel für eine schnelle Oberflächenaufnahme der Salzgehalts- und Temperaturverteilung gegeben. Experiments are discussed with two concentration cells of different construction. The emf of these cells depends on the concentration of chloride ions in solution because of the silver/silverchloride-electrodes used. The behaviour of cells with polyethylen membrans and with ion exchange membrans is compared by measurements with pure NaCl-solutions and with sea water. A potentiometric in-situ device is described and an example is given for a fast way of recording the surface distribution of salinity and temperature.

Description: Es wird gezeigt, daß man mit bekannten Routinemethoden der mathematischen Physik die Kenntnisse über Kinematik und Dynamik interner Wellen wesentlich gegenüber den aus der Theorie der Grenzflächenwellen bekannten Ergebnissen erweitern kann, wenn man mit einer exponentiellen Dichteverteilung rechnet. In den Abschnitten 1-3 werden bekannte Resultate zusammengestellt, Abschnitt 4 enthält eine Formel für die Wellenlänge interner Wellen (GI. 31). Die Energie interner Wellen (Abschnitt 5) erweist sich als erheblich größer als die der Grenzflächenwellen. In Abschnitt 7 werden Rechnungen über die Entstehung interner Wellen durch die Gezeitenkräfte, den Luftdruck und den Wind angegeben, und in Abschnitt 8 wird gezeigt, daß lineare inkompressible interne Wellen in der Tiefsee praktisch keine Dämpfung erfahren.

Description: Aus einem Material von je 1600 Seston- und Eiweißbestimmungen, die im Rahmen der deutschen Beteiligung am Polarfront-Programm des IGY gewonnen wurden, werden hier mittlere Tiefenverteilungswerte für diese beiden Komponenten der partikulären Substanz errechnet. Dabei ergeben sich Mittelwerte des Sestons für die Oberfläche zwischen 580 und 1810 µg/1 und für das Eiweiß von 28 bis 65 µg/1. Beide unterliegen in den obersten 50-100 m einer starken Reduktion (27-75%), die z. T. auf Akkumulation, z. T. auf Mineralisation zurückzuführen ist. Die Einzelwerte für große Tiefen (〉 1000 m) bewegen sich oft an der Grenze der Nachweisbarkeit; die Mittel betragen für das Südgebiet bei 1480 m Tiefe 100 bzw. 80 µg Seston und 6 bzw. 17 µg Eiweiß/l. Aus den Eiweißanalysen wird mit Hilfe tiefenvariabler Faktoren der Gehalt an lebender Substanz errechnet und daraus wieder durch Differenzbildung die mittleren Vlerte für den Detritusgehalt im hohen Ozean. Dieser beträgt an der Oberfläche 520 und 1190 µg/1 und sein Anteil im Spätwinter bzw. Spätsommer am Seston 76 und 79%. Ferner wird ein Vergleich zwischen Mittelwerten der gelösten organischen Substanz (n. Duursma) und denen der lebenden Substanz angestellt. Die Relation beider zu einander beträgt während der Sommeruntersuchungen 14.0 : 1 (51-100 m) bis 48.1 : 1 (401-500 m).

Description: Die Konstanz des zellulären ionalen Milieus, insbesondere die Aufrechterhaltung des ursprünglichen zellulären Kalium-Niveaus, ist eine wesentliche Vorbedingung für ein ungeschädigtes Überleben von Wirbellosen und Fischen in Ästuargewässern. The constancy of the cellular ionic medium, especially the maintenance of the original cellular potassium level, is an essential condition for the unharmed survival of invertebrates and fishes in estuarine waters.

Description: Zur Messung der Temperatur in Gebieten des Meeres mit starken Schwankungen der Schichtung wurde ein Meßverfahren entwickelt, das eine langzeitige Registrierung in einem verankerten Meßgerät erlaubt. Die Messung erfolgt über einen Thermistor in einer Wheatstone-Brücke, die Registrierung auf einem Fallbügelschreiber, die Steuerung über eine elektrische Uhr und Relaisschaltungen. Der Bereich umfaßt bei dem gebauten Gerät - 2° bis + 31° C, die maximal erreichbare Genauigkeit beträgt ± 0,1° C, als Betriebsdauer können bei einem Meßintervall von 5 Minuten ein Zeitraum von 50 Tagen, bei größeren Meßintervallen entsprechend höhere Zeiten erwartet werden. Eine Druckmessung zur Tiefenbestimmung und Eichungen der Anordnung erfolgen automatisch nach jeweils 21 Temperaturmessungen. Es werden das Meßgerät und die Laboratoriumstests sowie das Eichverfahren beschrieben, ferner werden Messungen mit dieser Methode in der Ostsee angegeben.

Description: Währcnd des in Norddeutschland ungewöhnlich kalten Winters 1962/63 trug die Elbe oberhalb von Hamburg mehrere Wochen lang eine 40-50 cm dicke Eisdecke, unterhalb der Stadt herrschte in dieser Zeit ständiges Eistreiben. Im Rahmen einer mehrjährigen mikrobiologischen Untersuchung wurde der Einfluß der anhaltenden Eisbedeckung auf das Bakterienleben im Strom studiert. Es zeigte sich, daß der Bakteriengehalt des Flullwassers wesentlich stärker als in normalen Wintern anstieg. Er belief sich besonders in dem Abschnitt oberhalb von Hamburg bei allen Stationen auf ein Mehrfaches der in der gesamten etwa 8 jährigen Untersuchungszeit vorher und nachher gewonnenen Maximalwerte. Die Ursache hierfür dürfte in erster Linie in dem Zusammentreffen von sehr geringer Wasserführung und anhaltend niedriger Temperatur liegen. Unter der Eisdecke kam es zu einer starken, vor allem von Mikroorganismen bewirkten Sauerstoffzehrung. Bedingt durch die anaeroben Verhältnisse erfolgte im Fluß eine lebhafte bakterielle Nitratreduktion (Denitrifikation). Diese wurde durch den kräftigen Rückgang des Nitratgehalts deutlich, der zunächst von einem starken Nitritanstieg begleitet wurde. Da die Nitratrcduktion über Nitrit bis zum freien Stickstoff führte, fand sich im Februar 1963 bei den meisten Stationen anorganisch gebundener Stickstoff fast nur noch in Form von Ammoniak. Laborversuche bestätigten, daß auch bei winterlichen Wassertemperaturen die Bakterientätigkeit noch stark genug ist, um den gesamten Sauerstoff in 02-gesättigtem Elbwasser innerhalb von 1 Woche zu verbrauchen. Das in der Elbe befindliche Nitrat kann dann ebenfalls in wenigen Tagen durch denitrifizierende Bakterien völlig über Nitrit zu freiem Stickstoff reduziert werden.

Description: Im Rahmen einer fischereibiologischen Fahrt von F.F.S. "Anton Dohrn" in das Gebiet der Faröer wurde im Januar 1964 eine eingehende Vermessung der Rosemary-Bank (φ = 59° 15' N, λ = 10° 10' W) durchgeführt.Als geringste Tiefe der isoliert gelegenen und teilweise steil aufragenden Kuppe wurden 325 m erlotet. Das annähernd kreisförmige Gipfelplateau besitzt Tiefen zwischen 400 und 700 m gegenüber 1400 - 2100 m in der weiteren Umgebung (Tafel 1 und 2). Der unsymmetrische Kegel weist nach W und S zu ein stärkeres Gefälle auf als an seinem E-Abhang. Am Fuß umgibt ihn als auffallendste morphologische Erscheinung eine ringförmige Mulde, deren Sohle 50 - 300 m tiefer liegt als der angrenzende Tiefseeboden. Im Anschluß an die Vermessung wurden außerdem zwei benachbarte Bänke abgelotet: Lousy-Bank (φ = 60° 25' N, λ = 12° 25' W) und Bill-Baileys-Bank (φ = 60° 35' N, λ = 10° 20' W). Die Tiefenverhältnisse der Gipfelregionen beider Bänke werden ebenfalls beschrieben (Tafel 3 und 4). In the scope of a fishery biological investigation made with F.R.S. "Anton Dohrn" in the area of the Faeroer Islands in January 1964 the topography of the Rosemary Bank (φ = 59° 15' N, λ = 10° 10' W) was exactly sounded. Lowest depth of the seamount is 325 m. The nearly circular summit plateau has depths between 400 and 700 m compared with soundings of 1400 to 2100 m in the environment (table 1 and 2). The cone which is not absolutely symmetrical is more declinated to the westside than to the east. As the most destinctive morphological phenomenon a ringshaped depression is surrounding the base of thc cone directly. lt is reaching down 50 - 300 m deeper than the neighboring deep sea bottom. In addition the depths of two further banks in the neighborhood of the Rosemary Bank have been sounded and their topography is described as follows: Lousy Bank (φ = 60° 25' N, λ = 12° 25' W) and Bill Baileys Bank (φ = 60° 35' N, λ = 10° 20' W). Bathymetric charts and sounding profiles are given in table 3 and 4.

Description: Es wurden Nordsee-Exemplare von Carcinides maenas aus Meerwasser von 30‰ Salzgehalt und Ostsee-Exemplare aus Backwasser von 15‰ Salzgehalt vergleichend untersucht. Die Atmungsintensität ganzer Ostsee-Exemplare übertrifft ebenso wie ihre Gewebeatmung die der Nordsee-Exemplare. Dabei ist die Stoffwechselintensität des Kiemengewebes der Ostsee-Individuen auch unabhängig von der Salzkonzentration des Atmungsmediums erhöht. Der Eiweiß- und der Hämocyaningehalt des Blutes der Ostsee-Exemplare sind im allgemeinen größer als der der Nordsee-Exemplare. Durch gekreuzte Anpassungen an Nordseewasser (30‰ S) und Ostseewasser (15‰ S) ließ sich zeigen, daß die Atmungsunterschiede und in zweiter Linie auch der Eiweiß-und der Hämocyaningehalt des Blutes von der Anpassung an den Salzgehalt des Außenmediums abhängig sind. Der Eiweiß- und Hämocyaningehalt des Blutes werden außerdem vom Ernährungszustand der Tiere beeinflußt. Die Ergebnisse machen es wahrscheinlich, daß die genannten physiologischen Unterschiede nicht genetisch fixiert sondern umgebungsbedingt sind. Comparative investigations were made on North Sea specimens of Carcinides maenas from normal sea water (30 per 1,000 S) and on Baltic Sea specimens from brackish water (15 per 1,000 S). The oxygen consumption of whole Baltic Sea specimens and their tissue respiration exceed considerably the corresponding values of North Sea specimens. The respiration of the gill tissue of brackish water specimens is also increased independently from salt concentration of the respiratory medium. The protein as well as the hemocyanin contents of the blood of Baltic-Sea specimens are normally higher than the corresponding values of North-Sea specimens. By alternating adaptation to North Sea Water (30 per 1,000 S) and Baltic Sea Water (15 per 1,000 S) it could be proved that the respiratory differences and secondly also the protein and hemocyanin contents of the blood are influenced by the adaptation to the salinity of the external medium. Besides the hemocyanin content of the blood is influenced by nutritional conditions of the animals. The results suggest that the physiological differences mentioned are environmentally induced rather than genetically fixed.

Description: Es wird über marin-vegetationskundliche Untersuchungen in der westlichen Ostsee (Kieler Bucht) berichtet. Für die Vegetationsaufnahme wurde eine Unterwasserfernsehanlage eingesetzt. Die Arbeit befaßt sich mit der großräumigen benthischen Vegetationsgliederung in der Kieler Bucht unterhalb der 5-m-Linie. Es werden die ökologischen Vegetationsbedingungen in diesem Gebiet diskutiert und die vegetationsphysiognomisch hervorstechenden Bewuchstypen dargestellt. A report on a survey of the marine vegetation in the western Baltic (Kiel Bay) is given. An underwater television set was employed for the vegetational mappings. This paper deals with the spatial distribution of the benthic vegetation in the Kiel Bay below the 5 m line. The ecological conditions for the vegetation in this area are discussed and the particularities governing the vegetational physiognomy are lined out.

Description: Die Hartbodenfauna der Schwentinemündung - ein Brackgewässer im westlichen Ostseebereich wurde untersucht. Der Salzgehalt nimmt in diesem Gewässer besonders in der Oberflächenschicht von der Einmündung in die Kieler Förde bis zu einem 2,4 km entfernt gelegenen Wehr kontinuierlich ab. Die Schwentinemündung läßt sich in 3 gegeneinander abgegrenzte Halinitätszonen gliedern. Jeder dieser Bereiche läßt sich durch eine spezifische Bewuchszone charakterisieren. Das größte Areal nimmt die α-mesohaline Zone ein. Sie wird von einer verarmten arktisch-borealen marin-euryhalinen Hartbodengemeinschaft (Mytilus edulis - Balanus crenatus-Biozönose) besiedelt. Die β-mesohaline Zone wird von einer südlich-borealen, marin-euryhalinen (brackischen) Hartbodengemeinschaft (Balanus improvisus - Membranipora crustulenta-Biozönose) bewohnt. Im α-Oligohalinikum breitet sich eine Grün- und Braunalgenzone aus, die von einer Mikrophytalgemeinschart bevölkert wird, welche sich zum größten Teil aus Brackwasserarten zusammensetzt.

Description: Im eulitoralen Bereich ebenso wie im Sublitoral wurden aus den jahreszeitlichen Veränderungen der Abundanz- und Dominanzverhältnisse der verschiedenen Fucus bewohnenden Tiergruppen Aspektfolgen erkannt. Es konnte die Eigenständigkeit der einzelnen Aspekte für die eulitorale Fucus-Zone und den Tiefen-Fucus gezeigt werden. Als Aspektbestimmend fielen im Eulitoral die Halacariden auf, während am sublitoralen Fucus die Nematoden besonders dedeutsam waren. Im eulitoralen Bereich stellte sich die Fucus besiedelnde Mikrofauna weitgehend als eine verarmte Fauna des Tiefenphytals dar, wies jedoch auch Arten auf, die in der eulitoralen Facus-Zone ihren optimalen Lebensbereich haben. Nur die Fucus-Bestände des Eulitorals erfüllen die Vorbedingungen eines Eigenbiotopes, für den Tiefen-Fucus ist dies im Ostseeraum nicht der Fall. Einteilung des charakteristischen Artenbestandes der eulitoralen Fucus-Zone in Charakterarten, dominierende Arten und Gäste gestattete das Hervorheben einer Art als Charakterart 1. Ordnung nicht, da keine stenöken Formen auftraten. Solche fanden sich auch unter den Epizoen nicht. Beziehungen zwischen Schleimabsonderung der Algen, Salinität und Ansiedlung von Bryozoen an bestimmten Teilen der Einzelpflanzen wurden bemerkt. Die Verbreitung einiger Amphipoden, Isopoden und Polychaeten an Fucus wurde kurz erörtert.

Description: Das Eulitoral des Roten Meeres ist trotz des extrem ariden Klimas, der hohen Insolation und des hohen Salzgehaltes von einer reichen Mikrofauna besiedelt. Die stärkste Artenentfaltung liegt im Bereich der sandsammelnden Rotalge Digenia simplex, die bisher noch nicht bekannte Lebensbedingungen im Eulitoral schafft. Die Sandregionen haben eine interstitielle Fauna, die in Zusammensetzung und Artenreichtum der der übrigen Meere ähnelt. Auch das subterrane Küstengrundwasser, das hier nur aus salzreichem Wasser besteht, enthält ebenfalls eine reiche Fauna. Die Anwurfzone (Wrack-Region) der Küste ist dagegen infolge der raschen Austrocknung des angespülten Pflanzenmaterials artenarm.

Description: In der Umgebung der Biologischen Station von Al Ghardaqa am Roten Meer wurden in verschiedenen Uferzonen freilebende Nematoden gesammelt. 49 verschiedene Arten wurden identifiziert, davon erwiesen sich 8 als neu. Die neuen Arten werden zusammen mit einer Anzahl bisher unzureichend bekannter Formen beschrieben.

Description: The dynamic and production of a natural population of the rotifer Brachionus plicatilis (0.F. MÜLLER) were studied by regular field sampling at routine stations in the shallow Darss Zingst estuary, southern Baltic (3-7‰ S). Investigations of the horizontal distribution revealed significant population growth during the summer months at salinities above 3‰ S and at those stations characterized by high eutrophication. The first individuals hatch from resting eggs in May. Significant reproduction occurs from June to September, when temperatures are above 15° C. Mixis rates were highest during the exponential growth phase. Instantaneous rates of growth, birth, and mortality were estimated. Mean P/B ratios for the growing season were high (around 0.7 d-1) and were in the range of values obtained from mass cultures in the field under subtropical conditions. In Barther Bodden annual biomass production for 1982 was 1.1 g fw · m-3. In its natural habitat, B. plicatilis serves as a food source for fish juveniles and the mysid Neomysis integer, the seasonal dynamics of the rotifer population were not significantly affected by predators.

Description: Shrimps Crangon crangon L. were exposed to 5, 7.5, 10, 25 and 50 ppm of the anionic detergent alkylbenzene sulphonate (ABS) added to brackish water (7‰ salinity). The animals were incubated in these solutions from one to nine days at 15° C or 20° C. After 24 h and 108 h of incubation the activities of arylsulphatase (E.C. 3.1.6.1 ), acid phosphatase (E.C. 3.1.3.2) and cathepsin D (E.C. 3.4.4.23) were assayed in homogenates of the hepatopancreas. The influence of the detergent ABS on the moulting cycle of the shrimps was also investigated. The activity of all acid hydrolases assayed descreased by 20 % to 50 % in the experimental shrimps, depending on concentration of the pollutant, as compared with the control group. The moulting cycle of the shrimps exposed to the action of the detergent was shortened from 31 % to 51 %, and the body weight during one moulting cycle was reduced by 24 % to 36 %. Survival times were reduced in the animals exposed to the action of the detergent. Total mortality of the shrimps occurred after 194 h, in 5 ppm of ABS at 15° C and after 108 h in 50 ppm. The 96 h LC50 for shrimp Crangon crangon L. under laboratory conditions was estimated as 27 ppm of alkylbenzene sulphonate.

Description: Prior to 1975, average winter water nutrient concentrations at station Bokniseck in Kieler Bucht (Western Baltic} were 1.23 mmol/m3 total phosphorus and 12.7 mmol/m3 dissolved inorganic nitrogen. Nitrogen concentrations did not change until 1984. The mean of a few total phosphorus data from 1980-1984 is 1.94 mmol/m3. Mean nutrient concentrations in the area between the southern entrance of the Great Belt and Darss Sill increased between 1975 and 1984 from 0.8 to 1.6 mmol/m3 total phosphorus and from about 6 to 10 mmol/m3 inorganic nitrogen. Comparatively higher nutrient concentrations at Bokniseck station are correlated to higher salinity. However, no data are available on nutrient imports into Kieler Bucht with saline deep water. Unchanged nutrient concentrations at Bokniseck prior to 1975 are an argument against any dominant influence of anthroprogenic inputs which until 1974 increased to annually 1500 t of total phosphorus and 12700 t of total nitrogen, plus 5000 t of nitrogen from the atmosphere. Higher phosphorus concentrations 1980-1984 are correlated to severe oxygen deficiency in the deep water. Mobilization of phosphorus from sediments becoming anoxic could be the reason. Biota could be such sources and sinks of nutrients that influence the nutrient balance of Kieler Bucht. To sum up, there are several processes besides anthropogenic inputs that influence nutrient concentrations in water. An assessment of winter water nutrient concentrations alone is no adequate tool for the evaluation of the effects of anthropogenic nutrient inputs via rivers, sewage, land runoff, groundwater and from the atmosphere.

Description: Postglacial sequence of migration and extinction has been studied in a boring through 10 m deposits in Jutland, Denmark. The main profile contained freshwater and brackish water fauna in the bottom layer. Hydrobia ulvae was first recorded at -9.75 m. Next H. ventrosa was found together with H. ulvae. Then H. neglecta appeared, and all 3 species co-occurred at -8.75 m. At -4.95 m H. ulvae disappeared but H. ventrosa and H. neglecta were still abundant until a depth of -1.90 m. It is concluded that H. ulvae and H. ventrosa quickly colonized the Littorina Sea while H. neglecta may have arrived somewhat later. H. ulvae has the largest larval shell, especially in the Baltic, and H. ventrosa the smallest larval shell of the 3 species. The ecological significance of two markedly different shell forms of H. ulvae is discussed. Postglacial hydrobiids are compared with recent specimens of the 3 species.

Description: In situ measurements of the functional response (feeding, respiration and excretion) of Mytilus edulis and Ciona intestinalis showed that the effects of 2.5 µg 1-1 tributyl tin and 100 µg 1-1 cadmium on an assemblage of the two species was lower than what could be predicted from the response of the two species separately. This is explained by biological interactions between the species and by the fact that the two species may react in different ways to the same disturbance. Thus, results from single species tests seem inadequate for making predictions of pollution effects in marine environments, and tests should instead be carried out at the community or ecosystem level.

Description: In order to determine the time of settlement, growth and mortality of young bivalves, samples sieved on 250 µm screens were taken in parallel to ordinary samples (1 mm screen) in the western part of the Limfjord, Denmark. High densities of newly settled Corbula gibba (30000-67000/m2) and Abra alba (16000-22000/m2) in August 1986 were found at most stations. Growth of the juvenile Corbula gibba was very rapid and the specimens were retained by the 1 mm sieve a few weeks after settlement. Growth ceased in October at a length of 2.9-3.5 mm for Corbula gibba and 0. 7-2.1 mm for Abra alba. The juvenile bivalves suffered high mortality within the first month after settling. It is suggested that this mortality may be due to predation from epibenthic predators.

Description: Seawater samples for algal experiments and isolation of OHS (Dissolved Humic Substances) were taken in the Gdansk Bay during intense phytoplankton blooms. Bioassay experiments were conducted under controlled laboratory conditions with water containing natural phytoplankton communities. OHS was isolated from seawater by absorption on Amberlite XA0-2 according to the method of MANTOURA and RILEY (1975). It was found that the enrichment of the medium with OHS increased the production of chlorophyll a and cell numbers. OHS addition to the culture medium caused a change in the dominant species, especially in spring and summer phytoplankton. The results show that OHS influence not only the phytoplankton production but also the species succession by altering the species composition. The phenomenon of large phytoplankton blooms in coastal areas during the last decade should therefore be related (besides other physical, chemical and biological influences) to the presence of increasing concentrations of dissolved substances of the humic type.

Description: In 1986 and 1987 a transect off SW Åland, N Baltic Sea was sampled for macrozoobenthos at 14 stations ranging from 1 to 226 m depth. In connection to this survey comparative samples were taken at a "standard depth" of 19-20 m at 2 additional stations to estimate variability in space and time. The data were analyzed for primary community parameters (i.e. no. of species, abundance and biomass) including spatial and temporal differences, and the information is evaluated in relation to topography and hydrography. A more detailed analysis using the dominant components of the zoobenthic communities illustrated some of the difficulties in monitoring of the marine zoobenthos. There were significant differences in abundances and biomasses even over short distances. The differences get even more pronounced when trying to relocate an exact station with another boat and using different grab types on the same station. This is exemplified by samples from a 19-meter station using a modified Olausen box corer and an Ekman-Birge type grab sampling on different days from different vessels; the primary community data obtained with both grabs was 10 vs. 10 species (with Pontoporeia affinis vs. Macoma balthica dominating), 1945 ± 529 vs. 2168 ± 385 ind/m2, and 21.6 ± 9.5 vs. 209.0 ± 45.3 g/m2, respectively. Similarily, samplings at stations less than 1 n. mile apart at 20 m depth using the Ekman-Birge grab yielded 2168 ± 385 and 7000 ± 607 ind/m2; a highly significant difference. The no. of species (10/13) and biomasses (209.0 ± 45.3/184 ± 89.0 g/m2) showed no significant differences. The data also showed some depth dependency, but there was no correlation (r=0.22) between abundance and biomass for the entire material pooled, illustrating the importance of always measuring both. When using keyspecies for monitoring purposes, their natural distribution should also be known, as the dominance-patterns shows clear gradients with depth and sediment type.

Description: During the winter 1984 and summer 1985, a series of limiting nutrient experiments (enrichment tests) were performed with coastal Baltic water by scientists from the German Democratic Republic, Poland and Sweden. The water used for the experiments was collected outside Warnemünde (GDR); Rostock (GDR}, Sopot (P) and Falsterbo (S). The bioassays were performed under similar laboratory conditions. Nitrogen was the potentially most limiting nutrient for phytoplankton biomass formation in coastal water from Rostock, Sopot and Falsterbo. During winter, before the spring phytoplankton bloom had started, phosphorus was the "most limiting" nutrient in the Rostock area. For the Warnemünde area, no clear limiting nutrient was found, except during July 1984, when nitrogen addition doubled the phytoplankton biomass. The lowest algal standing stocks were found for Warnemünde and Falsterbo, followed by Sopot. Extremely high chlorophyll-a values were found outside Rostock. Our results show that these coastal areas in the southern Baltic do not differ essentially from each other with respect to the most limiting nutrient (sensu Liebig), although their nutrient levels are quite different. Nutrient limitation experiments are discussed in the context of the assumed eutrophication of the Baltic.

Description: The paper presents the assumptions of a one-dimensional mathematical model of turbulent diffusion of marine suspensions, as well as the results of numerical investigations on the influence of dynamic conditions in a defined basin on the chlorophyll-a concentration. The influence of the duration and disappearance time of a disturbance, and the thickness of the layer disturbing uniform media of varying degrees of turbulence on the vertical distribution of the chlorophyll-a concentration is analysed.

Description: A large scale quantitative survey of the benthic vegetation of the Kiel Bight (Western Baltic Sea) has been performed by analysis of underwater television observations and samples obtained by SCUBA diving during 1985-86. This investigation was compared to a semiquantitative survey carried out in 1962-64 by SCHWENKE (1964, 1969). For the total study area (2571 km2), distinct changes in biomass and species composition have been observed. There is an increase of biomass above the 12 m level (probably with exception of the 6 m level) and a decrease below 12 m. Extensive Furcellaria lumbricalis populations have disappeared. Furcellaria lumbricalis has been replaced by Phyllophora truncata and Phycodrys rubens which are the predominant species at present. Among other possible causes for these changes, the role of commercial stone fishing and effects of increasing eutrophication in the Kiel Bight are discussed.

Description: The establishment of an initial association of marine benthos was investigated during a colonization experiment at the "Nordsee" research platform at 25 m depth, from April to December 1985 and 1986. Settlement and the early stages of succession were studied by taking monthly series of soft-bottom samples. Parallel to the experiment, recruitment in the natural habitat was studied at a reference station close to the platform. Number of species, density, diversity and evenness of the initial experimental association showed 3 different phases, similar to those described by RUMOHR (1980) as "pre-opportunistic, opportunistic and post-opportunistic" phases. These stages appear regularly during early succession, but, are subject to strong seasonal and annual variability. Heavy spatfalls of several species occurred in both years of the investigation; e.g. Tellina tabula, Echinocardium cordatum, juvenile ophiuroids of the genus Ophiura (mainly in 1985) and Scoloplos armiger, Mediomastus aff. fragilis and Abra sp. (1986). Total density attained maximum values of approx. 30,000 ind. per 0.1 m2. In the natural environment the colonization process was similar, but as in Kiel Bay, the densities were much lower than on the experimental substrates. The successional pattern and role of opportunists during early succession is discussed.

Description: Sven EKMAN (1876-1964), zoogeographer and limnologist in Uppsala, wrote significant articles on marine glacial relicts, drew up a proposal of the natural history division of the Baltic Sea and wrote the textbook "Tiergeographie des Meeres", first of its kind and later published in English as "Zoogeography of the Sea". - Adolf REMANE (1898-1976), zoosystematician and ecologist in Kiel, was one of the first to analyse the faunal composition and communities of the Baltic in "Die Tierwelt der Nord-und Ostsee". A pioneering textbook by him and C. SCHLIEPER "Biologie des Brackwassers" appeared also in English. REMANE found the interstitial habitat. He described numerous new Gastrotrichs, Rotifers and Archiannelids. - Carl SCHLIEPER (*1903), zoophysiologist in Kiel, is the founder of the "School of Baltic physiologists". Studies by him and his many students on salt water tolerance and osmoregulation, ionic and temperature adaptation and high pressure tolerance of aquatic animals are known world wide. He is the co-author of four textbooks. Sven G. SEGERSTRÅLE (*1899), zooecologist in Helsinki, initiated the yearly monitoring of the bottom fauna in coastal waters of Finland. He studied the systematics and ecology of amphipods, especially the genus Gammarus and Pontoporeia and biology of the mussel Macoma balthica. His descriptive articles on the Baltic Sea and studies on marine glacial relicts are well known.

Description: The effect of siderophores, cysteine and Na2EDTA in cultures of Chlorella vulgaris and Anabaena variabilis containing copper or cadmium, on the chlorophyll-a content, as well as on the rate of carbon fixation, has been investigated. Experiments on copper accumulation in Chlorella vulgaris cells grown in the presence of organic compounds have been also carried out. The siderophores, cysteine and Na2EDTA reduced the toxicity of copper and cadmium to axenic strains of algae and natural phytoplankton. No correlation between the toxic effect of copper and its bioavailability was observed.

Description: In the last 14 years, trapnet catches of the Baltic herring (Clupea harengus membras L.) have decreased drastically in the inner zones of the bays studied, but increased in the outer zones in the sea area of Turku, SW Finland. We deduce that the reasons for the decrease of catches have been eutrophication and sedimentation of the bays. The spawning grounds of the Baltic herring were studied by SCUBA-diving in the sea area of Turku in 1981-86. We studied 134 locations but found eggs in only 20 locations. Herring did not lay eggs on all suitable grounds, but regularly and intensively used some few locations from year to year. The most important spawning grounds were situated in the outer zones of the bays. We found eggs at 0-8 meters depth. In the inner parts of the bays, we did not find eggs with the exception of one shore, which is kept free of sediments by water currents. The spawning grounds comprised mainly sand and gravel. Most of them were covered by vegetation. Eggs were attached to Cladophora glomerata, Potamogeton perfoliatus, and red algae Furcellaria Jumbricalis and Phyllophora truncata. In the innermost zones of the bays the original littoral hard bottoms have changed to soft, muddy bottoms and consequently no eggs could be found there.

Description: In 1985 and 1986, a SW Finnish archipelago area was monitored for fish (using gillnets and seine), in order to investigate potential effects of salmonid fish farming on natural fish communities (population- and community level, growth and food choice). The results indicate some structural change eg. in total abundance and biomass values (increasing), on species composition (towards moore cyprinid-dominated communities), on growth rate (increasing) and food choice (increased proportions of fish consumed) of perch, and a general shift towards communities dominated by juveniles and small fish in areas influenced by fish farms.

Description: Recruitment and survival of Nereis diversicolor and Corophium volutator was studied in an artificial Saltwater Lagoon in the Danish Wadden Sea. The two species were the most successful colonizers of this lagoon and they have temporarily accounted for more than 80 % of the benthic individuals. Predation by waders, emigration and a low salinity in winter(〈2‰) appeared to be important regulators of the population sizes. Various field experiments have been performed to examine the effect of selected infaunal species on recruitment of C. volutator and N. diversicolor. The density of recruits of C. volutator was negatively affected by adult individuals of its own species, by C. arenarium, by Macoma balthica, and by Nereis diversicolor. C. arenarium was the only species that had a negative effect on N. diversicolor. At the intertidal flat a high recruitment of both, C. volutator and N. diversicolor, took place within cages enclosing the natural fauna, while the density of recruits on the adjacent bottom was low. The importance of epibenthic predators and cage artifacts on the density of recruits is discussed.

Description: The influence of eutrophication on the occurrence of the red algae Furcellaria lumbricalis and Phyllophora truncata was studied in the sea area of Turku. Due to increased sediment load and planktonic production, light penetration in the water has decreased in the northern parts of the study area. Furthermore, the quality of the sea bottom has changed. Plots of 1 m2 (N = 100} in the upper littoral zone (0.5-6 m} were studied by SCUBA diving, in order to investigate the factors controlling the occurrence of the red algae. Two transects were situated in the eutrophicated area, and two in the reference area. In the plots, the percentage cover of each plant species and of Mytilus edulis was documented, and the Secchi disc visibility and depth was measured. The numerical data were analyzed by correlation analysis and stepwise multiple regression analysis (BMDP2R}. In the eutrophicated area, abiotic factors (percentage cover of plain bottom and bottom quality} explained 81.28 % of the variation of red algae cover. In the reference area, the biotic factors (total number of species and Mytilus cover in %} were the most important factors, explaining 66.4 % of red algae cover.

Description: Major inflows of saline water into the Baltic Sea have a significant impact on the oceanological regime of the deep water in the central basins. Such events show seasonal characteristics, which are investigated here for the 80-year period from 1897 to 1976. The characteristic properties - i.e. salinity, temperature, density and oxygen concentration of the water bodies entering the Baltic during major inflows are analyzed for the first time. The significance of the season of the inflow event for its effects on the oceanological conditions in the deep water is discussed.

Description: 12-year quantitative phytoplankton data collected in the Tvarminne sea area in June-August from 1972-1985 were analysed in relation to environmental data collected at the same time. This was done by principal component analysis followed by canonical correlation analysis. A phytoplankton species succession which took place parallel to the increase in temperature was found to be the most important factor causing variation in species composition. The second most important factor was a change in phytoplankton species composition from the early 1970's towards the 1980's. This followed the same pattern as nutrient levels and total phytoplankton biomass. The species primarily responsible for the change were nanoplanktonic forms, such as unidentified flagellates, Cryptomonas spp., Monoraphidium contortum and Microcystis reinboldii, and a heterotroph, Ebria tripartita. It was concluded that this was due to increased levels of total phosphorus and organic load in the Gulf of Finland. Short-term weather conditions had no significant effect on species composition.