ALBERT

Description: Food samples from 27 Buller’s mollymawks Diomedea bulleri from the New Zealand region showed that cephalopods were, by frequency of occurrence and by mass, their preferred food. Fish, crustaceans, and tunicates, in decreasing order of importance, also were taken. Seventeen species of Cephalopoda were identified by their beaks, with 78.5% of individuals belonging to the Ommastrephidae (77% Nototodarus spp.) and 10% to the Histioteuthidae. The diet was compared with that of four other small species of Diomedea, and found to be similar to that of D. chrysostoma, D. irrorata, and D. cauta, but different from that of D. melanophris, whose preferred food is euphausiids. Squid-fishing operations around New Zealand may come into competition with Buller’s mollymawk.

Description: Squid regurgitated by Greyheaded and Yellownosed Albatrosses at the Prince Edward Islands were predominantly two onychoteuthid species, Kondakovia longimana and Moroteuthis knipovitchi. Both squid are characteristic of cold, Antarctic waters and may have been caught south of the Antarctic Convergence, some 350 km to the south of the breeding station. Both albatross species regurgitated similar squid (by species and size), and these squid were similar to those found in previous studies of the diet of Wandering, Sooty and Lightmantled Sooty Albatrosses at the Prince Edward Islands

Description: A collection of 130 specimens of Sepiola (ligulata, robusta, rondeletii, intermedia), 115 Rondeletiola minor, 90 Sepietta ( obscura, neglecta) and more abundant samples of S. oweniana obtained by trawl fishing in the Ligurian Sea are briefly illustrated in terms of depth distribution, sex ratio and maturity stages.

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: The diet of Northern Rockhopper Penguins Eudyptes chrysocome moseleyi breeding on Gough Island, south Atlantic Ocean was studied, during November 1984, 1985 and 1986 by stomach content analysis. Rockhopper Penguins fed chiefly on the euphausiids Thysanoessa gregaria, Euphausia lucens and E. similis. Fish and squid were of minor importance by mass but constituted the largest individual prey items.

Description: The feeding biology of the nectobenthic, sepiolid squid, Sepietta oweniana is treated based on behavioural observations in aquaria and stomach content analyses on 859 trawl caught squid. Juvenile squid in aquaria catch free-swimming prey, preferably the mysid Praunus flexuosus, day and night using the bottom only for shorter resting periods. Adult squid forage from dusk till dawn from positions close to the bottom and spend the day buried in the bottom. Praunus flexuosus is preferred as prey in comparison with demersal and benthic crustaceans as Palaemon elegans and Crangon crangon. Stomach analyses show that in daytime catches, only 16% of all analyzed specimens had stomach contents. Low frequencies were consistent throughout most sampled months in 1979 and 1982. Of the specimens with stomach contents most (50–100%) contained fragments of the euphausiid Meganyctiphanes norvegica. Specimens with remains of decapod shrimps were found in late spring and early summer. It is concluded that S. oweniana feeds in the hyperbenthic habitat at very low light intensities mostly on Meganyctiphanes norvegica in northern waters. A tentative ecological trade off explanation for this apparently inefficient feeding pattern is briefly discussed.

Description: Two species of arrow squid, Nototodarus (Oegopsida: Ommastrephidae), are caught in New Zealand waters. The close similarity in most morphometric characters has lead to confusion over the status of the two species. They are distinguished by the number of pairs of suckers on the first right arm; adult males are distinguished by the number of proximal tubercles and the morphology of the distal part of the hectocotylised arm; fresh or frozen specimens can be identified by gel elec‐trophoresis of the enzyme glycerol‐3‐phosphate dehydrogenase. Nototodarus sloanii is found in southern waters and N. gouldi in more northerly waters around New Zealand as well as southern waters of Australia. Differences between the two species are described and notes presented on their biology, abundance, and exploitation.

Description: The Imperial Cormorant Phalacrocorax atriceps is an inshore foraging, diving seabird (Cooper 1985) distributed throughout the southern hemisphere south of 45°S (Watson 1975). A brief description of the diet of the Imperial Cormorant at Marion Island has been published (Blankley 1981). We present here a more comprehensive report based on food samples collected throughout the year.

Description: The development of natural plankton populations in tanks (1000l) and in Kiel Bight is compared with special references to mechanisms affecting species composition in spring and early summer. In a first experiment, three tanks filled with surface water just prior to the bloom (February 1983) were held under different light conditions. Exponential growth coincided with onset of the growth in the field. Growth in the two darkened tanks was retarded. In the field, a bloom of mainly Thalassiosira polychorda was observed, whereas in the light tank Thlassiosira 'pseudonana' and in the two darker tanks Skeletonema costatum were the domninant species. The observed shift in species compositions between tanks and in the field can be attributed partly to differences in growth strategies of species involved but also to the specific effect of population enclosure. In a second experiment (May/ June 1983) the influence of grazing pressure was studied in two tanks with different abundance of metazooplankton. Nauplii as well as large protozoans were grazed down more rapidly than the samller phytoflagellates, which confirmed earlier hypotheses based on field observations. After decline of grazers, possibly due to starvation, a succession from bacteria to nanoflagellates and then ciliates was observed.

Description: Hurricanes and other strong storms can cause important decreases in sea surface temperature by means of vertical mixing within the upper ocean, and by air–sea heat exchange. Here we use satellite-derived infrared images of the western North Atlantic to study sea surface cooling caused by hurricane Gloria (1985). Significant regional variations in sea surface cooling are well correlated with hydrographic conditions. The greatest cooling (up to 5°C) occurred in slope waters north of the Gulf Stream where the seasonal thermocline is shallowest and most compressed; moderate cooling (up to 3 °C) occurred in the open Sargasso Sea where the thermocline is deeper and more diffused; little or no cooling occurred in shallow coastal waters (bottom depth less than 20 m) which were isothermal before the passage of hurricane Gloria. There is a pronounced right-side asymmetry of sea surface cooling with stronger (by a factor of 4) and more extensive (by a factor of 3) cooling found on the right side of the hurricane track. These qualitative results are consistent with the notion that vertical mixing within the upper ocean is the dominant sea surface cooling mechanism of hurricanes.

Description: In a midoceanic region of the northeast Atlantic, patches of freshly deposited phytodetritus were discovered on the sea floor at a 4500 m depth in July/August 1986. The color of phytodetritus was variable and was obviously related to the degree of degradation. Microscopic analyses showed the presence of planktonic organisms from the euphotic zone, e.g., cyanobacteria, small chlorophytes, diatoms, coccolithophorids, silicoflagellates, dinoflagellates, tintinnids, radiolarians, and foraminifers. Additionally, crustacean exuviae and a great number of small fecal pellets, “minipellets,” were found. Although bacteria were abundant in phytodetritus, their number was not as high as in the sediment. Phytodetrital aggregates also contained a considerable number of benthic organisms such as nematodes and special assemblages of benthic foraminifers. Pigment analyses and the high content of particulate organic carbon indicated that the phytodetritus was relatively undegraded. Concentrations of proteins, carbohydrates, chloroplastic pigments, total adenylates, and bacteria were found to be significantly higher in sediment surface samples when phytodetritus was present than in equivalent samples collected at the same stations in early spring prior to phytodetritus deposition. Only the electron transport system activity showed no significant difference between the two sets of samples, which may be caused by physiological stress during sampling (decompression, warming). The chemical data of phytodetritus samples displayed a great variability indicative of the heterogeneous nature of the detrital material. The gut contents of various megafauna (holothurians, asteroids, sipunculids, and actiniarians) included phytodetritus showing that the detrital material is utilized as a food source by a wide range of benthic organisms. Our data suggest that the detrital material is partly rapidly consumed and remineralized at the sediment surface and partly incorporated into the sediment. Incubations of phytodetritus under simulated in situ conditions and determination of the biological oxygen demand under surface water conditions showed that part of its organic matter can be biologically utilized. Based on the measured standing stock of phytodetritus, it is estimated that 0.3–3% of spring primary production sedimented to the deep-sea floor. Modes of aggregate formation in the surface waters, their sedimentation, and distribution on the seabed are discussed.

Description: Rhynchoteuthion stage ommastrephid larvae from New Zealand coastal waters were measured and the developing proboscis studied by scanning electron microscope. Many specimens show some retraction of the head and posterior mantle. Mantle shape is frequently cylindrical anteriorly and slightly expanded posteriorly. Arm 2 is generally longer than arm 1 after 2 mm dorsal mantle length (DML). Arm 3 develops around 2.0 mm DML but is too variable to include in an arm formula. Arm 4 develops around 2.4 mm DML. The proboscis tip bears 8 approximately equal sized suckers, evenly spaced and similarly orientated. The mean tentacle index prior to separation at the base is 3.74 .+-. 1.42 (1 std dev) n = 32. The proboscis is usually longer than all arms in length until 4.0 mm DML. Splitting of the proboscis base commences around 5.0 mm DML and earliest complete separation was observed at 8.4 mm DML. It is believed these larvae belong to Nototodarus sloani and Nototodarus gouldi.

Description: Change of colour, consistency and pH in contents of the caecum and the stomach of laboratory-maintained long-finned squid Loligo vulgaris reynaudii were determined. There was relatively little variability in any of these parameters of the specimens investigated. Colour and consistency of food or emulsion were used as a basis of analysis of stomach-caecum contents of wild squid. Most squid fed late during the night and/or during the early morning, and the frequency of caecum colour categories did not change much between trawls. Wild squid preyed upon different organisms according to their size. Squid of 69–125 mm dorsal mantle length fed mainly on euphausiids (95% by frequency of occurrence, 87,5% by mass) and those of 126–240 mm mainly on fish (78 and 74,3% respectively) with Bregmaceros?macclellandii and hake as important components. Unidentified fish in the stomachs (i.e. those from which no otoliths were available) probably also belonged to these two species.

Description: The western margin of the Tauera Window (Eastern Alps) is defined by a low angle westward dipping fault zone of potently We disp lacement. Ductile deformation of the fault rocks results in a carpet of mylonites up to 400 metres thick. Evidence from shear criteria and the excision of part of the Cretaceous-Tertiary metamorphic edifice both indicate normal displacements, and relative movement of Austroalpine nappe complex towards the west. The Sterzing-Steinach mylonite zone overprints the Alpine nappe edifice. Movements occurred on the cooling path of the Tauern metamorphism, and may be as recent as Middle Miocene. The Kinematics and geometry of the mylonite zone constrain two likely t ectonic explanations that are both compatible with secondary thining of a thick orogenic wedge. (1) Ute the Austroalpine nappe pile due to tectonic unroofing of the Tauern window. (2) Continental escape by east-west stretching of the Alpine orogenic wedge in response to continental collision.

Description: One of the most striking features of the upper North Atlantic Ocean is an extensive layer of water with temperature close to 18°C and salinity close to 36.5‰, (ref. 1). This 18°C water is formed by winter convection in the Sargasso sea2,3, but aspects of the annual rate of 18°C water formation remain obscure4. We have simulated this water mass formation by integrating a one-dimensional model along a 4-yr trajectory of a water column circulating around the Sargasso Sea. Winter convection is deep (≥200 m) in regions where the ocean suffers a net annual heat loss to the atmosphere, and shallow (≤lOOm) where the ocean gains heat each year. The origin of the thermostad (nearly isothermal layer) is a thick layer of nearly homogeneous water subducted beneath the seasonal boundary layer in the year that the water column passes through the line dividing annual cooling from annual heating. We estimate the annual production of 18°C water to be 446,000 km3 yr−1. Downstream, more stratified central water is formed each year at a rate that depends more on Ekman pumping (wind-forced convergence) than on the decreasing depth of winter convection

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: Chemical composition of Zostera marina L. seed and shoots was determined. Morphology and histochemistry of mature seeds were studied by fluorescence, brightfield and scanning electron microscopy to locate storage constituents in the seed. Starch content in the mature seed was 51% and was the major storage reserve in the embryo and a minor component in the testa. Starch in the shoots ranged from 0.3 to 2.3%. Protein, located in the embryo as small protein bodies, comprised about 9.0% of the seed. Protein in shoots ranged from 6–15%. Protein quality of both seeds and shoots resembled corn in composition, and the first limiting amino acid was lysine. Shoots were high in minerals, fiber and ash, while seeds were lower in these constituents. Fat was low (0.3–1.7%) in both shoots and seeds.

Description: Thirty seven juvenile specimens and one adult specimen of the cranchiid squid Mesonychoteuthis hamiltoni were captured by the opening and closing RMT8 net during RRS ‘Discovery’ cruise 100 (1979) in the Southern Ocean. The collection extends the size ränge of juveniles of this species previously described and illustrated. The small specimens resemble small juveniles of Galiteuthis glacialis, which also occur in most hauls, but are separated on the following characters : (a) M. hamiltoni lacks paired tubercles at the nuchal mantle fusion, (b) M. hamiltoni possesses a more capacious and thicker mantle, which is freer at the nuchal fusion and less constricted posterior to the opening; (c) juvenile M. hamiltoni up to a size of 26.5 mm (the largest in the present collection) have very small fins, while in G. glacialis of this size the posterior portion of the mantle has begun to extend into a tail and prominent fins appears; (d) M. hamiltoni has longer tentacles until it reaches a dorsal mantle length of approximately 25 mm. All specimens of M. hamiltoni were captured to the south of the Antarctic Convergence, and most were captured at depths between 20 m and 500 m apparently concentrated in the upper zone of ‘Warm Deep Water’ beneath the surface layer. Four newly hatched specimens were captured at 55°35’S between 20 and 500 m. The adult specimen was captured in a haul which had sampled a depth horizon from 2 000 m to 2 200 m.

Description: Marine organic carbon is heavier isotopically (13C enriched) than most land-plant or terrestrial organic C1. Accordingly, δ 13C values of organic C in modern marine sediments are routinely interpreted in terms of the relative proportions of marine and terrestrial sources of the preserved organic matter2,3. When independent geochemical techniques are used to evaluate the source of organic matter in Cretaceous or older rocks, those rocks containing mostly marine organic C are found typically to have lighter (more-negative) δ 13C values than rocks containing mostly terrestrial organic C. Here we conclude that marine photosynthesis in mid-Cretaceous and earlier oceans generally resulted in a greater fractionation of C isotopes and produced organic C having lighter δ 13C values. Modern marine photosynthesis may be occurring under unusual geological conditions (higher oceanic primary production rates, lower P CO2) that limit dissolved CO2 availability and minimize carbon isotope fractionation4.

Description: Seventeen advanced macrotritopus “larvae” from 7 to 15 mm mantle length were attracted to underwater lights in St. Croix, U.S. Virgin Islands. Their behavior was observed in situ, then seven were captured alive and one female was reared to an adult Octopus defilippi. The characteristic long arms of the planktonic young appear to function in flotation, feeding, crawling and defense. There is evidence that larger macrotritopus may be planktonic by night and benthic by day; thus the transition from a planktonic to benthic life may be controlled to ensure widespread distribution on to a suitable habitat. Morphological examination of 106 specimens from the Atlantic indicate that all macrotritopus “larvae” from this ocean are O. defilippi.

Description: A methodology is presented for obtaining egg masses from captive populations of the ommastrephid squid Illex illecebrosus and for incubating them intact under controlled conditions. Survival of rhynchoteuthion larvae for 9 days after hatching is the best reported to date, though it has not yet been possible to induce feeding. Factors critical to rearing success are discussed, e.g. tank size, stocking density, turbulence, light levels and photoperiod, as well as food type and concentration.

Description: The unique rhynchoteuthions of the ommastrephid squids are the smallest decapodan cephalopod hatchlings and have never been successfully reared. Based on anatomical and behavioural observations a mechanism of suspension feeding is proposed which depends on direct interception and inertial impaction on the mucus coated body surface. Mucus is transferred to the mouth area by ciliary motion and by observed cleaning behaviours. Suspension feeding is suggested to be a supplement to raptorial feeding but may be a critical "bridge" between small yolk reserves and the minimum development required for effective predation. Loss of ciliature through contact with vessel walls may prevent feeding in culture.

Description: The climate record obtained from two long Greenland ice cores reveals several brief climate oscillations during glacial time. The most recent of these oscillations, also found in continental pollen records, has greatest impact in the area under the meteorological influence of the northern Atlantic, but none in the United States. This suggests that these oscillations are caused by fluctuations in the formation rate of deep water in the northern Atlantic. As the present production of deep water in this area is driven by an excess of evaporation over precipitation and continental runoff, atmospheric water transport may be an important element in climate change. Changes in the production rate of deep water in this sector of the ocean may push the climate system from one quasi-stable mode of operation to another.

Description: There is now clear evidence that changes in the Earth's climate may be sudden rather than gradual. It is time to put research into the build-up of carbon dioxide in the atmosphere on a better footing.

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: Loligo vulgaris was reared to a maximal size of 75 mm dorsal mantle length and 28.2 g wet weight. Experiments lasting up to 140 days permitted obser vations on feeding densities, feeding preferences and grovvth rate. Hatchling mortality was very high; between 50 and 100 percent of the dead squids were missing statoliths which are needed for swimming and orientation. The growth results are compatible with the concept of a one-year life cycle for this species.

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: Rhynchoteuthion larvae of three species of ommastrephid squids from Hawaiian waters were identified, and aspects of their ecology examined. Important taxonomic characters for field Identification include the number and location of photophores, length of the proboscis (fused tentacles), size at which the proboscis completely divides and the relative sizes of the suckers on the proboscis tip. Other taxonomic characters include sucker structure and chromatophore patterns. Variation among species were found in both temporal and vertical distributions.

Description: The diet of Ommastrephes bartramii (Lesueur, 1821) was determined by analysing the stomach contents of 73 squid caught in the South-West Atlantic Ocean. There were three main prey groups, Cephalopoda (in 82% of the squid stomachs), Osteichthyes (34%) and Crustacea (18%). Cannibalism was common. Squid of the families Histioteuthidae and Enoploteuthidae and other teuthoids were less frequent in the diet. The fish prey was predominantly Myctophidae, of various species. The bulk of the prey was mesopelagic species that migrate into the epipelagic layers at night.

Description: Laboratory observations on egg size and change of capsule dimensions during embryonic development of Loligo forbesi are reported and compared with Loligo vulgaris. Shipboard observations made on freshly caught live L. forbesi permitted records of settling and recovery of freshly laid egg capsules.

Description: While carrying out a systematic revision of the pelagic squid genus Octopoteuthis, the author examined 146 “larval” specimens of the genus from museum sources worldwide. Individuals could not be separated into species but morphometric and meristic characters were examined giving information on ontogenetic development. Specimens ranged in size from 1.3 to 27.0 mm dorsal mantle length (DML) and represented locations in the Atlantic, Pacific and Indian Oceans and also the Mediterranean Sea. Captures were made with a variety of trawls and plankton nets. The deepest record from a closing net was 1 200 m using a MOCNESS system. The largest group examined totalling 105 individuals was collected in the North Atlantic. In the Atlantic the highest larval occurence was found to be in March, April, and June (which may reflect higher sampling pressure in those months) but specimens were obtained in all months except January and December. Low numbers in each of the other oceans prohibited an evaluation of yearly larval distribution.

Description: Feeding strategies are different when adult Illex illecebrosus prey on large (trout) and small fish (mummichogs). Attacks on trout are characterized by (1) rotation as the squid changes from tail‐first to head‐first swimming; (2) an approach phase involving rapid acceleration towards the prey; (3) a tracking phase where the squid slowly follows the trout; (4) the capture phase. No tracking phase is present in attacks on mummichogs. These differences in feeding strategies can be explained by performance limitations of the squid jet propulsion system. Head‐first acceleration rates in Illex are low (max. = 12 m • s−2) and maneuverability poor compared to fish. A large fish could thus out‐perform an attacking squid if forced into evasive action. The tracking phase is a type of oceanic stalking strategy designed to bring the squid into close proximity to larger fish. The behaviour is not necessary when attacking small fish due to their low swimming speeds.

Description: Larval squid were sampled in three surveys off the eastern Australian coast in January, March and May 1983. Ommastrephid larvae were abundant and occurred at over 90 % of stations. Although Identification to species level has not so far been possible for the majority of specimens, general patterns of distribution with respect to latitude and bottom depth are presented.

Description: Oxygen consumption and ammonia excretion rates were investigated in young Octopus maya (hatching to 139 days old; 0.11–81.23 g wet body weight, BW; 22.5–23.9°C), young squids of Loligo forbesi (hatching to 45 days old; 9.4–115.3 mg BW; 12.3–13.1°C) and young squids of Lolliguncula brevis (2.00–39.98 g BW; 23.8–24.7°C). Except at hatching, oxygen consumption and ammonia excretion rates on an individual basis (M) of these three cephalopods increased linearly with increasing body weight (BW) expressed as M = aBWb . Values of b for oxygen consumption were 0.900, 0.910 and 0.848 and for ammonia excretion were 0.744, 0.809 and 0.751 for O. maya, L. forbesi and L. brevis, respectively. Among the three species the value a varied widely, while b was similar for both oxygen consumption and ammonia excretion rates. Based upon these data, metabolism for hatchlings of O. maya and L. forbesi was estimated to be relatively lower than that of older juveniles. The O/N ratios for hatchlings of O. maya and L. forbesi were relatively high and indicate an apparent dependence upon lipids in the immediate post‐hatching period, followed by standard protein energy utilization thereafter.

Description: Long-term investigations of pore-water ammonium concentrations and sediment oxygen uptake were carried out in three different sediment types along a slope in Kiel Bight. The inverse relation between mineralization rates and ammonium concentrations at the three stations is explained by the differences in the role of various mechanisms transporting nutrients out of the sediments. Direct water exchange due to turbulent or density driven processes, bioturbation and pumping activity of benthic macrofauna and molecular diffusion are involved to various extents in nutrient fluxes out of the sediments studied. The role of different sediment types in the interaction with the pelagic system is discussed in a conceptual framework of pelagic system functioning in Kiel Bight.

Description: An inventory of the rocky infra- and circalittoral zone between Port Bou and the Isias Medas (NE-Spanish coast), based on 140 SCUBA dives in July 1985, led to the listing of 58 ascidian species for this region. In this article we present some data on the bionomical distribution of the species and biological observations.

Description: This investigation contribute to our knowledge of the pigment content of certain previously described Cyanophycea found in symbiotic association with sponges and ascidians (Duclaux, 1977; Lafargue and Duclaux, 1979). It is opportunity to test the hypothesis of a single symbiont Synechocystis trididemni Lafargue and Duclaux associated both with Trididemnum cyanophorum Lafargue and Duclaux and T. tegulum. Phycoerythrin characteristics suggest that T. cyanophorum contains a cyanophyte symbiont which is different from the cyanophyte symbiont of T. tegulum.

Description: This is the first report of Prochlorophyta in association with the genus Polysyncraton, a Didemnid Ascidian (Tunicata). The species P. bilobatum Lafargue, 1968 is common near Galapagos islands as well on the European and the West-African coasts. It is a key species in the evolutive line of the Didemnidae in the French coast and probably in the world.

Description: The publications of Matsuoka (1983) and Bujak (1984) on dinoflagellate cysts from the Neogene of Japan and the Paleogene‐Neogene of the Bering Sea‐northern North Pacific areas, respectively, resulted in the erection of two new species by each author which are synonymous. Impagidinium pacificum Bujak and Spiniferites ovatus Bujak are therefore designated junior synonyms of Impagidinium japonicum Matsuoka and Spiniferites hexatypicus Matsuoka. Another species, Spiniferites ovatus Matsuoka, does not occur in the material examined by Bujak. Specimens assigned by Matsuoka to Nematosphaeropsis labyrinthea and Tectatodinium pellitum are reassigned to Nematosphaeropsis lemniscata Bujak and Filisphaera filifera Bujak, respectively. The species Reticulatosphaera stellata Matsuoka, which Matsuoka designated the type species of his new genus Reticulatosphaera, is designated a subjective junior synonym of a species originally named by Benedek (1972) as Cleistosphaeridium actinocoronatum. C. actinocoronatum is transferred to Reticulatosphaera and becomes the type‐species of this genus. Specimens assigned to Areoligera senonensis Lejeune‐Carpentier sensu Gocht 1969 by Matsuoka (1974, 1983) and Tanyosphaeridium fusiform by Matsuoka (1974) are reattributed to Systematophora ancyrea and Distatodinium fusiforme (Matsuoka) comb, nov., respectively. Bujak also erected eight Eocene to Pleistocene concurrent‐range zones, two of which were named the I. pacificum and Spiniferites ovatus Zones. These are renamed the I. japonicum and 5. hexatypicus Zones, and the zonation is modified to extend the Trinovantedinium boreale Zone into the early Oligocene, and to restrict the S. hexatypicus Zone to the Miocene.

Description: Morphological characteristics of two large females of Haliphron atlanticus STEENSTRUP (= Alloposus mollis VERRILL) are described and illustrated. The soft and gelatinous body, the shape of the mantle aperture, the formation of the funnel and adhesive apparatus, and the straplike septa connecting the mantle and funnel and containing the stellate ganglion are characteristic features of the species. One specimen, weighing 41 kg after fixation, was found dead near Bergen (60°14′ N, 5°16′ E) in May 1983. The other, weighing 25 kg after being frozen, was caught alive at 210 m off Vestvägöy in the Lofoten archipelago (68°20′ N. 14°14′ E) in November 1984. It was possibly feeding on the prawn, Pandalus borealis KRøYER. Both specimens had arms partly missing and web torn, but were otherwise well preserved. Previous records of H. atlanticus are confined to tropical and warm-temperate areas. The present findings represent the first records from north of 42° N.

Description: The first recorded specimens of Scaeurgus unicirrhus from the South-East Atlantic are described. Five males and two females were captured on the Valdivia Bank, Walvis Ridge, between 24 and 27°S, 400 miles off the Namibian coast. They are compared with specimens caught from other areas, and historical and geographic surveys of the species are made.

Description: This check-list is a compilation of the marine molluscs recorded from Norway and the abyssal depths of the Norwegian Sea. Molluscs not recorded from the Norwegian fauna but found on the North Sea plateau, the British North Sea coast, the Swedish west coast, and in Danish waters are also included. Distributional data are provided for each species. Most commonly used synonyms are listed, together with type species for each accepted generic name. Systematical code numbers are included for easy retrieval of information. An alphabetical index of all generic names mentioned concludes the check-list. Recent taxonomic alterations and all distributional records are documented by literature references.

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.

Description: The history of studies of benthic flora and fauna in the Northern Baltic Sea (N of 58° N, including the Gulfs) is briefly reviewed from the early naturalists of the Linnaean period (mid-18th century) to the early 1970's.

Description: Fish eggs and larvae were sampled during 1970 and 1971 at approximately monthly intervals in the Kiel Bay using a Bongo-Net. Samples of 0.5 mm mesh net were considered in this study. At every station temperature and salinity were measured. The most abundant fish eggs were of sprat origin, followed by flounder, cod and plaice. Spawning areas of this species are also described. Fish larvae showed high abundance from June to August with gobies predominance. Commercially important species such as herring, cod and plaice were present in low numbers. Species exceeding the 5 % relative proportion level (tow-year average) were herring, sprat, rockling, gobies and gunnel.

Description: The Bornholm Basin has a distinct hydrographical pattern in terms of temperature, salinity and oxygen. Due to the strong differences in density, there is a strong vertical stratification of water masses and ichthyoplankton as well. The vertical distribution of fish eggs and larvae was investigated in a period of 27 hours at an anchor station. Samples were taken at three hours intervals with a closing net. The species composition of fish eggs and fish larvae in (), both in percent, was found to be 79.7 (84.0) sprat, 17.5 (15.0) cod, 1.3 (0.6) rockling, 1.5 (0.4) flounder and 7.3 dead eggs. To control for water masses around the station, double oblique hauls with a ring net were performed, as well as measurements of temperature and salinity. The vertical distribution of sprat and cod eggs showed considerable differences. Sprat eggs were most abundant in the upper 40 metres, whereas cod eggs were found only from 40 metres downwards. The few eggs of rockling and flounder showed a weak accumulation between 40 to 65 metres. Sprat and cod larvae were present throughout the whole water column, decreasing in numbers with depth. The maximum abundance overlapped for sprat and cod between 40 to 65 metres. However, sprats were also common in the upper layer, in which cod were present in small numbers only. The larvae of rockling and flounder were generally scarce and not found in every sample. No aggregation was obvious at certain depth levels.

Description: Predation on zoobenthos by fish was studied on Åland, northern Baltic Sea, in a shallow, semi-isolated bay (Station 1) and an outer area (Station 2) which is in direct connection with the bay. The fish sampling was done under an one year-cycle (May-November 1984 - May-June 1985) with a standardized multimesh set of gillnets. The fish samples for community analysis were taken once a month (May-November 1984 - May-June 1985). Stomach samples of perch (Perca fluviatilis, L.), roach (Rutilus rutilus, L.) and ruffe (Acerina cernua, L.) were collected five times during the sampling period representing the spring-, summer- and autumn-seasons. The fish species studied are the most important predators on benthic macroinvertebrates in this area. Calculations of the annual food consumption were done on the basis of field data and literature values. The soft bottom infauna was monitored throughout the study to get accurate measures of the standing stock. Roach was the most abundant and important bottom feeder in the study areas. It consumed 64 to 73 % of the total amount of benthic food taken. Roach preyed heaviest on molluscs. Perch preyed mainly on crustaceans (at St. 2) and insect-larvae (at St. 1). It consumed about 24 to 35 % of the total amount of fish predation. Ruffe is principally an obligate benthic feeder consuming mainly insect-larvae, crustaceans and polychaetes. The abundances of ruffe were low in the study areas, and the quantities consumed were marginal on an annual basis. The total consumption calculated was 999 kg/ha at St. 2 and 349 kg/ha at St. 1 during the summer season (May-November). Consumption is significantly higher in the outer area (St. 2) mainly due to higher fish abundances and benthic biomass in this area. The consumption values are equivalent to about 9 to 31 % of the annual secondary benthic production in the area studied. The fish consumed a significant proportion of the benthic standing stock, but simultaneous experiments in the lab and field have shown that the structuring effect of fish-predation on the benthic community is small. The ecological relevance of the fish/benthos couplings on shallow soft bottoms are further emphasized.

Description: In static toxicity tests, the effects of HgCl2 and of an organic mercury complex on the mortality of Neomysis integer and Pomatoschistus microps were determined under various temperature and salinity conditions. Definite species-specific differences with respect to combined temperature, salinity and mercury effects were found. The toxicity of the organic mercury complex exceeded that of HgCl2 by a factor of 20 in the case of N. integer, and by a factor of 30 in the case of P. microps. By means of continuous respiration and activity measurements on N. integer (the more sensitive species) under organo-mercury contamination at different environmental conditions (temperature, salinity and pO2), reproducible sublethal concentrations were determined. For this species, a direct relationship was found between mercury contamination levels, increase in activity, and oxygen uptake.

Description: On the occasion of the celebrations of the 50th year of existence of the biological station at Hiddensee (1982), the 150th jubilee year of the Zoological Institute of the Ernst-Moritz-Arndt-University in Greifswald (1986), and the 25th year of existence of an independent marine biological research and training facility at the University of Rostock (1985), a short overview is given of the development of biological science in the Baltic Sea in the Hither Pomerania and Mecklenburg region. It will become clear that the initiative for brackish water research arose at the University of Greifswald, with algological studies concentrated at Hiddensee and zoological-ecological work in Greifswald itself. Effective and successful marine biological research and teaching at the University of Rostock started with the establishment of the Department of Marine Biology (1960), where university marine biological activities are now concentrated as a result of the university reform (1968).

Description: Shrimps (Crangon crangon L.) were exposed to 5, 7.5, 10, 25, or 50 ppm of light fuel oil, heavy fuel oil or crude oil at 15° C or 20° C with aeration. The mortality was recorded. It was found that light fuel oil was the most toxic and crude oil the least toxic.

Description: The genus Enteromorpha Link is one of the most common algae in the Gulf of Gdańsk. The literature mentions that several Enteromorpha species occur in the western part of the Gulf of Gdańsk. The material for analysis was collected in the littoral zone down to a depth of 1 m in the Gulf of Gdańsk and on the open Baltic coast once a month from April to November 1986. The taxonomical characters, the nature of the bottom sediments and the sampling season were used for describing OTUs. 6 dissimilarity coefficients and 7 clustering methods were employed. The two principal clusters and some intermediate OTUs are shown on the dendrograms. The difference between these two clusters lies in the morphological characters. In one of them, the filaments are unbranched, without prolification, and the cells are multilateral and rounded, setting in random fashion; in the second one the filaments are branched, and the cells are rectangular, setting in an orderly manner along the main axis and the branches. The remaining characters, especially the quantitative ones do not seem to be important from the cluster analysis point of view.

Description: Cadmium, lead, copper, chromium and zinc contents were determined in otoliths of the cod Gadus morhua L. from the Southern Baltic. It was shown that the levels of these heavy metals fluctuated during the period of investigation (1969-1985). It was found that levels of Cd, Cu, Cr and Zn decreased with age and age-dependent morphometric parameters, while the amount of lead increased. Sex of cod did not affect the level of bioaccumulation of these five trace elements in the otoliths. With the exception of Cu no differences were found between heavy metal contents in otoliths of cod from the Gdańsk and Bornholm Deep.