ALBERT

Description: Abschnitt 2.6 Bohrlochgeophysik, 10 S.

Description: Oogenesis in four commercial Caribbean sponge species, Hippospongia lachne, Spongia barbara, S. cheiris and S. graminea, was studied using light and transmission electron microscopy. Eggs and embryos develop asynchronously in localized endosomal nurseries of these viviparous and gonochoristic species. Statistical analyses of specific morphological characteristics of reproductive elements have unequivocally identified four specific stages in the process of oogenesis. Oogonia undergo mitotic division to produce primary oocytes. Meiotic division occurs producing secondary oocytes which are fertilized before zygotes undergo major growth by phagocytosis and the transfer of nutrients through cytoplasmic bridges. During cleavage of the zygote, umbilici form between embryos and nurse cell layers and these function in the transfer of symbiotic bacteria and other mesohyl substances from the maternal parent to the embryo. These symbionts were observed dispersed between blastomeres of all young and maturing embryos and between internal cells of cytodifferentiated parenchymella larvae. Extracellular transfer of symbiotic bacteria from maternal tissues to developing embryos has not been reported in any other viviparous invertebrate.

Description: Before 1985, Martialia hyadesi (Cephalopoda: Ommastrephidae) in the Pacific Ocean was known only from the Eltanin Fracture Zone and Macquarie Island. A joint Japan‐New Zealand squid survey around New Zealand captured many immature ommastrephid squids. Gel electrophoresis confirmed the presence of immature M. hyadesi. Aspects of the external morphology are described. The distinctive tentacle club was evident in the smallest specimen examined, 19 mm dorsal mantle length (ML). Arm trabeculae were first evident in specimens of 40–50 mm ML. Immature squid were distributed around and southward of the Subtropical Convergence Zone. The presence of very small squid (〈 10 mm ML) indicated spawning on or near the Auckland Island Shelf.

Description: Sexual reproductive cycles of a Florida, U.S.A., population of four Caribbean commercial sponge species, Hippospongia lachne, Spongia barbara, S. cheiris and S. graminea, were determined by analysis of tissue samples collected over a three-year period. Spermatogenesis in these species was studied using light and transmission electron microscopy. The production of male gametes occurs in cysts within the endosomal tissue of mature specimens. Reproductive elements within an individual cyst develop synchronously while development between cysts is asynchronous. All available evidence suggests that these species are dioecious. Spermatogonia differentiate directly from choanocytes in situ. All cells of the chamber lose their collars and flagella and undergo mitosis to produce primary spermatocytes, each possessing a single flagellum. The ratio of nucleus to cell diameter in these cells is almost double that of choanocytes. Circumstantial evidence suggests that primary spermatocytes undergo meiosis to produce four spermatids, but confirmational chromatid linkage figures are still lacking. The mature spermatozoa lack both intermediate segments and acrosomes. Male gametes displayed a bright yellow-white autofluorescence when excited with blue light (460–485 nm).

Description: Squid on their spawning grounds feed mainly at night when they are more dispersed. In all, 28,5 per cent of squid sampled at night had food in their stomachs, whereas only 6,7 per cent of those collected by day had food. Most stomachs contained only a single prey species (90,8% of those analysed). Teleosts dominated the prey of squid collected at night (58%M), followed by crustaceans (25%), polychaetes (9%) and cephalopods (3%). By day the prey was dominated by cephalopods (61%), followed by teleosts (20%), crustaceans (14%) and polychaetes (2%). Bregmaceros sp. was the most frequently identified teleost, Loligo vulgaris reynaudii (cannibalism) the dominant cephalopod, ?Betaeus sp. (Alpheidae; pieces of coral were also found) the commonest crustacean and Nereis sp. the commonest polychaete. There were seasonal differences in the diet too: squid caught during summer seemed to have similar proportions of the four main prey components. Also, the incidence of feeding was higher than in winter. There were, however, no significant differences in stomach mass expressed as a percentage of body mass between day and night nor between season nor between sexes. The average stomach mass of all samples was 0,6 per cent of body mass, less than on the feeding grounds, where it is generally about 2 per cent.

Description: The moult fast in emperor penguin (Aptenodytes forsteri) chicks was studied during January 1990 at Drescher Inlet, eastern Weddell Sea. In early January feeding of the chicks had stopped and about 4,000–5,000 chicks were in the inlet. The number of starving chicks decreased rapidly until 26 January when all chicks had either left the inlet or died. Mean body mass loss of starving chicks was 257 g/day and the evaluated specific daily mass loss was 25 g/kg body mass. The critical body mass, i.e. the mass below which chicks die, during moulting starvation was estimated to be 4 kg. Mean body mass was higher and mass loss lower in chicks at more advanced moult stages. Chicks left the inlet before moult was completed, although the sea-ice was still stable.

Description: The areas of marine pollen deposition are related to the pollen source areas by aeolian and fluvial transport regimes, whereas wind transport is much more important than river transport. Pollen distribution patterns ofPinus, Artemisia, Chenopodiaceae-Amaranthaceae, and Asteraceae Tubuliflorae trace atmospheric transport by the northeast trades. Pollen transport by the African Easterly Jet is reflected in the pollen distribution patterns of Chenopodiaceae-Amaranthaceae, Asteraceae Tubuliflorae, andMitracarpus. Grass pollen distribution registers the latitudinal extension of Sahel, savannas and dry open forests. Marine pollen distribution patterns of Combretaceae-Melastomataceae,Alchornea, andElaeis reflect the extension of wooded grasslands and transitional forests. Pollen from the Guinean-Congolian/Zambezian forest and from the Sudanian/Guinean vegetation zones mark the northernmost extension of the tropical rain forest.Rhizophora pollen in marine sediments traces the distribution of mangrove swamps. Only near the continent, pollen ofRhizophora, Mitracarpus, Chenopodiaceae-Amaranthaceae, and pollen from the Sudanian and Guinean vegetation zones are transported by the Upwelling Under Current and the Equatorial Under Current, where those currents act as bottom currents. The distribution of pollen in marine sediments, reflecting the position of major climatic zones (desert, dry tropics, humid tropics), can be used in tracing climatic changes in the past.

Description: The enoploteuthid cephalopod Abraliopsis lineata is re-described and its generic position discussed. Specimens for the present study were captured during the Indian Ocean Expedition of RV Meteor in 1987, where the species occurred in considerable numbers. The geographical distribution of A. lineata is described and discussed. The detailed analysis of the photophore pattern of the present specimens differs from the original description. The diagnostic features in the male, especially the structure of the hectocotylus which separates A. lineata easily from the members of the subgenus Pfefferiteuthis, are outlined. The morphological differences which separate A. lineata from A. gilchristi, the only other member of the subgenus Micrabralia, are summarized.

Description: In den 1980er Jahren wurden umfangreiche Bestandsaufnahmen zur Formenvielfalt der Fischkrankheiten sowie der saisonalen und regionalen Fluktuation ihrer Befallsraten in deutschen Küstengewässern angestellt. Sowohl Formenvielfalt als auch viele der Befallsraten scheinen im Wattenmeer und insbesondere in den dortigen Flußmündungen größer zu sein als in Vergleichsgewässern. Drei “neue” Krankheitsformen werden vorgestellt: die nahrungsinduzierte Maulgranulomatose des Stints, die vermutlich durch Flexibacter-Bakterien verursachte Gelbe Pest des Kabeljaus und eine Fibrom des Steinpickers, in dem lentivirusähnliche Partikel nachgewiesen wurden. Das Schwergewicht der bisherigen Forschungsvorhaben lag auf dem Sammeln von Felddaten. Mangels experimenteller Arbeitsansätze müssen viele wichtige Fragen zur Bedeutung dieser Krankheiten daher heute noch unbeantwortet bleiben. So bleibt die Vermutung unbewiesen, daß ein Reihe von parasitenbedingten Krankheiten einen entscheidenden Beitrag zur natürlichen Sterblichkeit vor allem von jungen Nutzfischen im Wattenmeer liefert. Auch das komplizierte Wirkungsgefüge anthropogener und natürlicher Faktoren bei der Entstehung von Fischkrankheiten im Gebiet wird ohne gezielte experimentelle Arbeiten nicht aufzudecken sein. Das Auftreten von Gelber Pest, Ichthyophonus-Krankheit und lentivirusähnlichen Partikeln in Fischtumoren stellt ein beträchtliches Gefährungspotential für die deutsche Fischwirtschaft dar. Allgemein ist festzustellen, daß in Deutschland eine große Empfänglichkeit gegenüber Umweltproblemen auf dem Gebiet der Marinen Pathologie besteht. Die nationalen Forschungskapazitäten sind aufgrund anderer, meist kurzfristig angelegter Arbeitsschwerpunkte jedoch nicht ausreichend darauf vorbereitet, diese Probleme auch erfolgreich zu analysieren und zu bewerten. Als Konsequenz wird gefordert, der bislang vernachlässigten Grundlagenforschung auf dem Gebiet der Marinen Pathologie neben der reinen Datenerhebung auf See künftig eine größere Bedeutung zuzumessen. Das gilt insbesondere für experimentelle und für biochemisch- und mikroskopisch-diagnostische Arbeiten. Künftig auftretende Probleme werden nur dann rechzeitig zu bewerten und zu lösen sein, wenn sich ein ausreichend breit angelegtes und fundiertes Wissenspotential kontinuierlich weiterentwickeln kann.

Description: Larval behaviour, settlement, and metamorphosis were investigated in four Caribbean commercial sponges, Hippospongia lachne, Spongia barbara, S. cheiris and S. graminea, using light and transmission electron microscopy. The parenchymella larvae of these viviparous and gonochoristic species have an average size of 350 μm by 420 μm when released. Symbiotic bacteria occur intercellularly in both larvae and post-larvae. Laboratory behavioural studies demonstrate that free-swimming larvae display directional swimming with constant lateral rotation and negative phototaxis. Larval settlement occurs 26–56 hours after release from the parent and involves the formation of a basal lamella between the post-larva and substrate. There is no evidence of larval substrate selection by type or orientation. The canal system begins to form six days after settlement and oscules are apparent eleven days post-settlement. Available evidence suggests that larval ciliated epithelial cells are terminally differentiated and do not appear to contribute to formation of post larva or adult in this group of Porifera.

Description: The present study demonstrates that a distinct land-associated community of mesopelagic micronekton exists around the Hawaiian Islands. This “mesopelagic-boundary community” replaces the oceanic mesopelagic community over bottom depths of approx 400 to 700 m and includes about 14 species of fishes, 5 of shrimps and 4 of squids. Similar species of the mesopelagic micronekton have been reported in association with other landmasses at the boundary between the oceanic mesopelagic realm and upper continental or island slopes. These species may form a cosmopolitan “mesopelagic-boundary community” which shows regional differences in taxonomic composition, abundance and diversity. Boundary communities, with populations which are both tightly constrained geographically and relatively accessible to shore-based research programs, offer unique opportunities for studying biological processes of the mesopelagic realm and the interactions between neritic and oceanic populations. Data is presented from three midwater and two neuston sampling projects undertaken around the main Hawaiian Islands between 1987 and 1989; additional evidence from the literature is also discussed.

Description: To evaluate the feasibility of feeding Sepia officinalis on artificial food, a food pellet consisting of Palaemon serratus powder and alginate as binding agent was developed and tested. Six of seven cuttlefish clearly ingested the artificial food during the ten days it was supplied.

Description: Knowledge concerning biology of two loliginids and three sepiids which are found in the Japanese waters was reviewed including unpublished information of the authors. The swordtip squid, Photololigo edulis, is one of the most important resources for the coastal fisheries of Kyushu and the prefectures facing the southwest Japan Sea. This species is the only species of genus Photololigo found along the Japanese mainland coast and is easily distinguished from other loliginids, by the light organs on the ink sac. The species is distributed from southern Japan to the Red Sea. The spawning season extends throughout the year. Egg cases are laid in clusters on the sandy bottom. The life span is about one year. In the juvenile stage they feed on Crustacea and after reaching pre‐maturity they prey mainly on fish, but many have empty stomachs. Most catches are made by jigging and trawler. The fishing season extends throughout the year. The fishing grounds are widely spread over the continental shelf. Annual catches are around 25 000 metric tonnes. Although this level varies from year to year, it is fairly stable. Fishing has probably little effect on the stocks. The spear squid, Heterololigo bleekeri, can be easily distinguished from other loliginids by its shorter tentacles. The species is endemic in the Far East waters. The stocks are larger in the north. The spawning season is winter in south Japan, and from spring to early summer in north Japan. Egg cases are laid beneath the undersurfaces of firm substances. The life span is about one year. Its feeding behaviour is similar to that of the swordtip squid. Catches are made mainly with bottom trawler and fixed nets from autumn to spring. Annual landings fluctuate widely from year to year. Several prefectures along the northern Japan Sea coast are promoting the large scale development of artificial spawning beds of the species to increase the stocks. The three sepiids, golden cuttlefish. Sepia esculenta, kisslip cuttlefish. Sepia lycidas, and spineless cuttlefish, Sepiella japonica are important in mainland Japan. Those three spawn from spring to early summer in the innermost waters of semi‐enclosed inlets. Eggs are laid in batches of 50–300 every day for 3–4 days followed by a rest period of 1–2 days. This pattern is repeated until several thousands of eggs have been laid. The life span of Sepia esculenta and Sepiella japonica is one year. They feed mainly on decapod crustaceans and fish but as growth proceeds the proportion of fish increases. They are fished mainly by cuttlefish trap and beam trawler. In the early 1960s annual landings were 20 000 metric tonnes but since 1980 catches have decreased below 10 000 metric tonnes. Of the three species, the stock of Sepiella japonica is the most fluctuable. Judging from the result of the stock assessment studies on Sepiella japonica in the western Inland Sea, their stocks have been over‐exploited.

Description: A seabird and mammal census was carried out in the north-eastern Weddell Sea during the austral winter of 1986. The German research icebreaker Polarstern operated in heavy pack ice along the Greenwich Meridian between the northern sea ice boundary and the Antarctic coast. Crabeater seals (Lobodon carcinophagus), minke whales (Balaenoptera acutorostrata), Adélie penguins (Pygoscelis adeliae), Antarctic petrels (Thalassoica antarctica) and snow petrels (Pagodroma nivea) were found to be more abundant in the vicinity of the submarine Maud Rise, about 700 km north of the continental margin, than in other areas of substantial ice cover traversed during that cruise. The aggregations of birds and mammals are expected to reflect aggregations of their principal food, krill (Euphausia superba) wintering underneath the ice cover. The distribution pattern of krill predators coincides with the course of a warm water belt upwelling near Maud Rise. This upwelling could induce local ice melting which in turn may result in an increased release of sea ice algae.

Description: In 1987 and 1989 coelacanths were observed for the first time in their natural habitat with the help of submersibles. Coelacanths were found between 150–253 m depth, their preferential depth seems to be around 200 m; the water temperature ranged between 16.5–22.8° C. During the day coelacanths aggregate in small non-aggressive groups in sheltered lava-caves. Caves might be a limiting factor for distribution. At night they leave the caves for hunting by drifting singly along the steep lava slopes. They migrate between different caves located within a large home range covering more than 8 km coastline. Coelacanths are site-attached, some for a period of at least 2 years. Our own observations and earlier catch records show that only the west coast of Grand Comoro is a suitable coelacanth habitat with more structural complexity and prey fish abundance than other coastlines of the island. From our survey we estimated a total coelacanth population off Grand Comoro to be 150–210 individuals; a saturated population would be 370–510 individuals. This small relict population seems to be stable. International protection of coelacanths against commercial interests is needed.

Description: We report first observations on social behavior ofLatimeria chalumnae in its natural environment at around 200 m depth in the Comoro Archipelago, Western Indian Ocean. Coelacanths aggregate in small nonaggressive groups in sheltered lava-caves. They live in open site-attached social systems with individuals occupying large overlapping home ranges of more than 8 km coastline, some for a period of at least 2 years.

Description: This paper describes (i) the Recent distribution pattern of various types of carbonate sediments in Troms county (northern Norway), and (ii) the onset of carbonate sedimentation after the final deglaciation of the Fennoscandian ice-shield. The distribution of major facies belts is strongly dependent on hydrographic and topographic constraints. The main bulk of carbonate deposits is derived from maerl-producing coralline algal biotopes that are restricted to the photic zone of waveprotected areas and influenced by tidal currents. Furthermore, extended mollusc and echinoderm-rich arenites are present in the area investigated. In deeper subtidal areas, terrigenous sediments of Late Weichselian to Early Holocene age are preserved. However, these are strongly influenced by later winnowing processes, generating a coquina lag deposit that serves as a secondary hardground for a diverse fouling community. The Holocene facies successions can be seen in several raised outcrops, containing the transition from glacigenic to Recent non-glacigenic depositional conditions. Autochthonous radiocarbon dated rhodolith banks, which mark the onset of carbonate sedimentation, yielded surprisingly young ages of 5,500 YBP. Around 5,500 YBP, present-day oceanographic and climatic conditions had already been firmly established. This time-lag can be explained with the behaviour of postglacial sea level fluctuations in the area. From 10,000 their cooperation in this project. We address our sincere thanks specifically to Prof. T.O. Vorren, Dr. M. Hald, Dr. B. Gulliksen, Dr. J. Hansen, Dr. J.J. Møller, Dr. E. Thomsen, and Dr. G. Corner for their dedicate help in organizing our field trips in Troms and for extensive scientific discussions. Special thanks to capitain K. Bendiksen for his patience and professional skill while operating the vessel ‘OTTAR’ in the skerry area even under bad weather conditions. S. Rasmussen and G. Ellingsen assisted during the cruises and very kindly introduced us to the Norwegian way of life. Special thanks to the two reviewers (Prof. Dr. W.-Ch. Dullo and anonymus) for their critical but constructive remarks. J. Welling and Dr. M. Kaminski improved the language of the final version of the manuscript. This project is part of the German Science Foundation’s main research program ‘Globale und regionale Steuerungsprozesse biogener Sedimentation”. Financial support was kindly provided by the Deutsche Forschungs-gemeinschaft (He 1671/1-1, 2).

Description: In the Atlantic sector of the Southern Ocean, data from vertebrate predators and commercial fisheries suggests that the distribution of the ommast rephid squid Martialia hyadesi is related to the Antarctic Polar Frontal Zone, but it spreads further to the north in some years (Rodhouse, in press). A mass stranding of M. hyadesi occurred on Macquarie Island in 1971 (O'Sullivan et al. 1983) suggesting that its distribution is c ircumpolar (Rodhouse and Yeatman 1990). However, apart from a single beak collected from the s tomach of a wandering albatross at Mar ion Island (Imber and Berruti 1981) its presence has not, until now, been confirmed in the Indian Ocean sector and in particular it is not included in the list of cephalopods from the Kerguelenian Province (Lu and Mangold 1978). M. hyadesi is a major prey item of the grey-headed albatross, Diomedea chrysostoma, and the southern elephant seal, Mirounoa leonina, at South Georgia (Rodhouse et al. 1990; Rodhouse et al., unpublished data) and is present in the diet o f several other predators in the Scotia Sea area including the wandering albatross, Diomedea exulans (Rodhouse et al. 1987) and the giant petrels, Macronectes halli and M. gioanteus (Hunter 1983). It occasionally occurs as a significant by-catch in the lllex argentinus fishery on the Pa tagonian Shelf and has been taken during commercial squid jigging trials in the Scotia Sea at the Antarctic Polar Frontal Zone (Rodhouse, in press). It appears to have potential for commercial exploitation in the sub-Antarctic waters of the Atlantic sector of the Southern Ocean (Rodhouse 1990). In view of the ecological importance of M. hyadesi to Antarctic predators, and the likelihood that it will be commercially exploited in the future, it is important to thoroughly establish its geographical range, and in particular to confirm its circumpolar distribution.

Description: The model presented here provides an explanation of the rapid response of atmospheric CO2 to increasing solar insolation. In the glacial ocean, during periods of slow, deep water renewal, when less oxygen is supplied to the deep ocean and into sediments, manganese oxide in the sediments is reduced and forms soluble MnCO3 and stays in the water column. The dissolved Mn-carbonate should then reach a concentration of ≥ 10µMol/liter, approximately 5,000 to 104 times larger than it is at present. This is the mode prevailing until deep water formation at high latitudes starts again. As soon as the balance between oxygen and organic matter becomes oxidizing once more, the deposition of MnO2 recommences. Oxidation of dissolved Mn2+CO3 to Mn4+O2 which is a spike of acidity to the ocean, rapidly lowers the CO3−− concentration in the water column and enhances release of CO2 to the atmosphere, producing the observed events of CO2 increase at the transitions from glacials to interglacials. The surprising conclusion is that the oceanic (redox-) cycle of a minor element may have had a major impact on Earth's climate.

Description: Seit jeher will der Geologe wissen, aus welchem Material die Erde besteht, wie ihre Struktur aussieht und welche physikalischen, chemischen und biologischen Vorgänge dabei im Laufe der Erdgeschichte zusammengewirkt haben. Indessen muß er sich, wie alle Historiker, auch heute noch weitgehend damit bescheiden zu ermitteln, wie und wann etwas geschehen ist, und nicht, warum. Daran ist vor allem die Komplexität der Fragen schuld und die Schwierigkeit, einschlägig zu experimentieren.

Description: Factors influencing the fate of ice algae released from melting sea ice were studied during a R V Polarstern cruise (EPOS Leg 2) to the northwestern Weddell Sea. The large-scale phytoplankton distribution patterns across the receding ice edge and small-scale profiling of the water column adjacent to melting ice floes indicated marked patchiness on both scales. The contribution of typical ice algae to the phytoplankton was not significant. In experiments simulating the conditions during sea ice melting, ice algae revealed a strong propensity to form aggregates. Differences in the aggregation potential were found for algal assemblages collected from the ice interior and the infiltration layer. Although all algal species collected from the ice were also found in aggregates, the species composition of dispersed and aggregated algae differed significantly. Aggregates were of a characteristic structure consisting of monospecific microaggregates which are likely to have formed in the minute brine pockets and channels within the ice. Sinking rates of aggregates were three orders of magnitude higher than those of dispersed ice algae. These observations, combined with the negligible seeding effect of ice algae found during this study, suggest that ice algae released from the melting sea ice are subject to rapid sedimentation. High grazing pressure at the ice edge of the investigation area is another factor eliminating ice algae released during melting. Data presented here were collected during the European Polarstern Study (EPOS) sponsored by the European Science Foundation

Description: Zooplankton was sampled by a Rectangular Midwater Trawl (RMT 1 + 8) in Weddell Sea surface waters (0 to 300 m) between 66 and 78°S during austral summer (February – March 1983). Sixty-nine taxa including different developmental stages were considered and divided into 16 size classes between 〈1 and 〉39.5 mm length. Biomass was determined by taxon and size class for three different meso- and macroplankton communities in the oceanic region, on the northeastern shelf and on the southern shelf of the Weddell Sea. The highest biomass of 11.2 mg DW m−3 (3.4 g DW m−2) was found in the northeastern shelf community (70 to 74°S), where juvenile and adultEuphausia crystallorophias accounted for 3.7 mg DW m−3 (1.1 g DW m−2). Although not quantitatively sampled, early copepodite stages (CI to CIII) ofCalanoides acutus andCalanus propinquus ranked second with 2.7 mg DW m−3 (0.8 g DW m−2). Biomass in the northeastern shelf community was concentrated in the size ranges 1 to 4 mm and 19.5 to 39.5 mm. The oceanic community of the central Weddell Sea was dominated by copepods smaller than 5 mm, which made up half of the total oceanic biomass. The tunicateSalpa thompsoni (7.0 to 8.5 mm) was the dominant single species with 1.6 mg DW m−3 (0.5 g DW m−2). Euphausiids, mainly juvenile and adult krillEuphausia superba, comprised 1.2 mg DW m−3 (0.4 g DW m−2). Total standing stock in the oceanic community was 9.4 mg DWm−3 (2.8 g DW m−2). Lowest biomass values were found in the southern shelf community (south of 75°S) with 4.0 mg DW m−3 (1.2 g DW m−2), concentrated in the 1 to 4 mm and 14.5 to 34.5 mm size classes. Abundant species were the pteropodLimacina helicina (1 to 2 mm; 0.7 mg DW m−3; 0.2 g DW m−2) andE. crystallorophias (24.5 to 39.5 mm; 0.9 mg DW m−3; 0.3 g DW m−2). The data reveal that it is essential to distinguish among subsystems in the Southern Ocean. This leads to a better understanding of the structure and function of those pelagic food webs which represent alternatives to the paradigmatic krill-centered system.

Description: The dependence of results from coarse-resolution models of the North Atlantic circulation on the numerical advection algorithm is studied. In particular, the sensitivity of parameters relevant for climate simulations as e.g., meridional transport of mass and heat and main thermocline thickness is investigated. Three algorithms were considered: (a) a central difference scheme with constant values for horizontal and vertical diffusion, (b) an upstream scheme with no explicit diffusion, and (c) a flux-corrected transport (FCT) scheme with constant and strictly isopycnal diffusion. The temporal evolution of the three models on time scales of centuries is markedly different, the upstream scheme resulting in much shorter adjustment time whereas the central difference scheme is slower and controlled by vertical diffusion rather than advection. In the steady state, the main thermocline structure is much less diffusive in the FCT calculation which also has much lower heat transport. Both horizontal circulation and overturning in the meridional-vertical plane are strongest in the upstream-model. The results are discussed in terms of the effective vertical (diapycnal) mixing in the different models. A significant increase in vertical resolution would be required to eliminate the high sensitivity due to the numerical algorithms, and allow physically motivated mixing formulations to become effective.

Description: Planktonic foraminifera first appeared in the Early Jurassic, approx. 200 million years ago. They occurred in great abundance in the oceans only after an important marker Ievel of 130 million years (Early Cretaceous). Since that time, planktonic foraminifera are the most important first ranking Stratigraphie markers and indicators forachanging world's ocean. Knowledge of the ecological demands of living planktonic foraminifera help one to understand their environment in the past because of their high sensitivity to environmental changes; thus, they can be used to reconstruct the oceanic paleoclimate by means of their morphology, faunal assemblage and chemical composition.

Description: The role of substratum surface tension on the colonization process (fouling) on artificial substrata was investigated in Kiel Bay (Western Baltic). The density of organisms from the major groups (bacteria, microalgae, protozoa, macroorganisms) was monitored on test panels after several exposure intervals in two experimental series. The results showed that substrata with a surface free energy of 24 mN/m were initially less densely colonized by representatives of the different fouling groups. The most hydrophobic substrata and those between 31–43 mN/m were heavily colonzied but there was a slight decrease in density towards the most hydrophilic material (glass). After an immersion time of 64 d these differences were not apparent for bacteria, microalgae or protozoa. These results correspond with thermodynamic predictions, which propose minimum bioadhesion on substrata with critical surface tensions between 20–25 mN/m in seawater. In addition, factors other than the surface tension may be important in marine fouling.

Description: Predation among pelagic cnidarians and ctenophores is reviewed. The diets of semaeostome scyphomedusae and hydromedusae commonly include other gelatinous zooplanktivores. However, few species of siphonophores and ctenophores are known to consume other gelatinous species. Most of these species can be said to exhibit intraguild predation, since they consume species that potentially compete with them for food. In addition, some hydromedusan and ctenophore species may consume other gelatinous zooplanktivores exclusively. Characteristics of cnidarians and ctenophores as predators and as prey of other gelatinous species are discussed.

Description: Using bacteria that tolerate fairly high sodium sulphate concentrations and reduce sulphate and a coarse clay with buffering properties as solid electrolytes, biological fuel cells have been developed for providing electrical energy discontinuously. The biological active anodes, which accumulate fuel, contained a metal hydroxide catalyst that was converted during the biological process into a metal sulphide catalyst and functioned in a solidified aqueous electrolyte that contained sodium sulphate. The active carbon or titanium cathodes employed were activated with cobalt oxide spinels, molybdenum/vanadium compounds or metal chelates. When employed in continuous service for discontinuous energy consumption, fuel cells were capable of being operated with humus constituents or sugar waste as fuel over a period of 5 years without malfunction and maintenance. Positive results were achieved in the purification of waste-water with a modified type of fuel cell in which the production of energy was not dominant.

Description: A large-scale trawl survey in August 1989 and data from other surveys indicate that the mesopelagic zone (depth 200-500m) of the Sea of Okhotsk is most densely populated with squids, wit maximum catches of more than 500kg/h. The greatest concentrations occur above the continental slope, particularly in the northern TINRO basin and off the southwestern coast of Kamchatka, adjoining the most productive regions of the sea. Five squid associations are distinguished in terms of the makeup of the catches.

Description: The methodology for analysis of marine mammal diets may be thought of as a series of choices; about the sampling regime, the type of sample, the processing of samples, the identification of prey remains, the quantification of prey importances, and the estimation of population food consumption. In addition to directed sampling, samples may be obtained directly or opportunisitically and the most frequently used types of sample are gut contents of dead animals, and faeces. Direct observation of feeding may be possible for species living inshore, and humane approaches to sampling (e.g. lavaging) have been succesfully applied to seals, but all methods are subject to bias. Identification of fish prey usually relies on recognition of otoliths, but additional information may be obtained from other hard remains or serological analysis of proteins. Remains of invertebrate prey may also be identified from hard parts. A variety of methods exists for quantifying the importance of prey in marine mammal diets. The most useful currency is probably prey biomass but, for fish, natural variation in otolith size-fish weight relationships makes it difficult to estimate fish weights from otolith size. Also, otoliths are reduced in size or lost during digestion. Notwithstanding these problems, otoliths are widely used. If the diet of a population has been adequately characterised, the amounts of each prey type consumed may be derived from direct or indirect estimates of energy requirements. Ideally the measurements should be taken in the field. Possible improvements in methodology include improved calibrations for otolith measurements, the development of keys and guides to fish bones, and of serological methods for identifying fish proteins. Feeding is normally inferred rather than directly monitored and a means for remote detection of prey ingestion and defaecation would greatly enhance the interpretation of foraging activity. To predict diet choice it is necessary to undertand the underlying behavioural mechanisms. Measurement of the energetic costs of prey capture would be an important step in this direction.

Description: The energy consumption of Adélie penguins while at rest in water (8.4 W·kg-1 at 4°C) or swimming below the surface was determined using a 21 m long canal fitted with respiration chambers at each end. Penguins chose to swim 86% of the time at speeds recorded in nature. Cost of transport was lowest (7.9 J·kg-1·m-1) at 1.7–2.3 m·s-1, corresponding to a power input of 15.8 W·kg-1, and only 50% as high as previously reported. Assuming a muscle efficiency of 0.25, propulsion efficiency is 0.4 and overall efficiency is 0.1. Calculated food requirements vary between 1060 g krill per adult and foraging trip at the beginning of the breeding season and 2500 g at the period of highest demand, prior to crèching of the chicks.

Description: Opportunistically collected information on sea temperature and wind was used in a preliminary investigation of physical factors affecting jigged catches of chokka squid Loligo vulgaris reynaudii. Results revealed sea temperature and wind to be correlated with catches during part of the summer upwelling season (October and December) in 1988. Multiple linear regression analysis confirmed that sea temperature was a highly significant explanatory variable (p = 0,0000) for catches from three boats, as well as for the overall catch. Wind direction also played a significant role (p = 0,0085) in the overall catch. A statistical linear multiple regression model is proposed for each boat and for the total catch. Upwelling events are suggested to play a major role in the availability of squid on the inshore spawning grounds (〈50 m) during summer. With further study, other independent physical variables, such as currents, swell height and turbidity, are likely to be introduced into the proposed model.

Description: The feeding patterns of fish caught on the inshore (〈50 m deep) spawning grounds of chokka squid Loligo vulgaris reynaudii were investigated between November 1988 and September 1990. Fish were sampled by demersal trawl, gillnet, handline and longline. SCUBA was used to observe interactions in situ. Potential predators consisted of 16 species each of teleost and elasmobranch. Of the teleosts, five species preyed on whole squid and one appeared to have scavenged squid fragments. Of the elasmobranchs, 12 species had squid in their stomachs, nine of these with a high incidence (〉33% frequency of occurrence). The squid were in spawning condition when taken and no spent squid were recovered from stomach contents. There was no evidence that squid had been moribund when ingested and no dead or moribund squid were encountered while diving during the two-year study. Cannibalism by squid was observed. Marine mammals and avian predators were rarely sighted on the spawning grounds.

Description: The enoploteuthid cephalopod Abraliopsis lineata is re-described and its generic position discussed. Specimens for the present study were captured during the Indian Ocean Expedition of RV Meteor in 1987, where the species occurred in considerable numbers. The geographical distribution of A. lineata is described and discussed. The detailed analysis of the photophore pattern of the present specimens differs from the original description. The diagnostic features in the male, especially the structure of the hectocotylus which separates A. lineata easily from the members of the subgenus Pfefferiteuthis, are outlined. The morphological differences which separate A. lineata from A. gilchristi, the only other member of the subgenus Micrabralia, are summarized.

Description: Climatologists generally expect an anthropogenic global warming that could raise sea level 50-150 centimeters in the next century and more thereafter. One of the impacts would be the loss of coastal wetlands. Although the inundation of adjacent dry land would enable new wetlands to form, much of this land is or will soon be developed. If developed areas are protected, wetlands will be squeezed between an advancing sea and the land being protected, which has already happened in China and the Netherlands, where people have built dikes for centuries. Unlike those countries, the United States has enough land to accommodate the landward migration of wetlands; but governments lack the funds to purchase all the coastal lowlands that might be inundated and the legal authority to prohibit their development. We propose a third approach: allowing property owners to use coastal lowlands today as they choose, but setting up a legal mechanism to ensure that the land is abandoned if and when sea level rises enough to inundate it. Although compensation may be required, this approach would cost less than 1 percent as much as purchasing the land, and would be (1) economically efficient by enabling real estate markets to incorporate expectations of future sea level rise; (2) constitutional by compensating property owners; and (3) politically feasible by pleasing people who care about the long-term fate of the coastal environment without disturbing people who either are unconcerned about the distant future or do not believe sea level will rise. Because planning today would be more effective than reacting later, the U.S. government should develop a long- term strategy in the next three years.

Description: Different initial mixtures of phyto-and zooplankton from different lakes were grown under identical chemical and physical conditions in medium size (8-and 12–1) laboratory microcosm cultures until convergence of phytoplankton species composition was attained. Five such experiments with four (four experiments) or three (one experiment) microcosm cultures were run. Three experiments were performed with weak stirring which permitted sedimentary elimination of the diatoms. Two experiments were conducted with stronger stirring to prevent sedimentation. In the three ldquosedimentation intensiverdquo experiments, the final phytoplankton community was composed of the filamentous chlorophyte Mougeotia thylespora together with a smaller biomass of nanoplanktic algae. In the two ldquosedimentation freerdquo experiments the final phytoplankton community consisted of pennate diatoms. Both dissolved nutrient concentrations and the chemical composition of biomass suggested strong nutrient limitation of algal growth rates in the final phase of the experiments. The zooplankton communities at the end of the experiments were composed of species that were apparently unable to ingest the large, dominant algae and that presumably fed on the nanoplanktic ldquoundergrowthrdquo and the bacteria. There was a distinct sequence of events in all experiments: first, the large zooplankton species (Daphnia and Copepoda) were replaced by smaller ones (Chydorus, Bosmina, rotifers); second, all cultures within one experiment developed the same nutritional status (limitation by the same nutrient); and third, the taxonomic composition of phytoplankton of the different cultures within one experiment converged. The last took 7–9 weeks, with is about 2–3 times as long as the time needed in a phytoplankton competition experiment to reach the final outcome.

Description: The Jurassic carbonate series of the Lechtal and Allgäu Nappes in the central part of the Northern Calcareous Alps reflect formation of orogen-parallel structures with swells and basins. Regional facies patterns display the morphologies of the various depositional environments. During the Middle Jurassic, an elongated swell evolved parallel to the overall structural strike in the central part of Lechtal Nappe, while in the southern part a basin started to subside. This configuration reflects the initial stage of rotational block faulting on the southern continental margin of the Tethys. Similar structural and facies settings were also established in the northern part of the Lechtal Nappe and in the southern Allgäu Nappe. Synsedimentary tectonics induced a variety of downslope sediment mass movements and increased facies differentiation on the slopes. In the upper section of the middle Jurassic sequences red nodular limestones with frequent intercalations of intraformational breccias and conglomerates indicate downslope sediment movements. During the Oxfordian, the Tethyan-wide deposition of radiolarites also covered the basin in the southern Lechtal Nappe. Contemporaneous deposition of pelagic radiolarian-bearing limestones dominated on the slope of the surrounding northern swell, while its peak was covered by a shallow water carbonate facies, e.g. a specific pseudopeloid and oolithic facies, which was also injected downslope into the pelagic facies. The Oxfordian to Tithonian section reveals a characteristic pelagic carbonate facies succession, e.g. with Protoglobigerina facies at the base, followed by aSaccocoma facies and a calpionellids facies on top. In the northern Lechtal Nappe and in the Allgäu Nappe various similar radiolarite basins with intersected swells were discovered.

Description: A pathogenic species of marine slime mold, Labyrinthula, has been identified as the etiological agent of the present recurrence of wasting disease of eelgrass, Zostera marina. It is also implicated as causing the previous epidemic eelgrass wasting disease that occurred in the 1930s. We propose Labyrinthula zosterae sp. nov. for this pathogen based on its host specificity, cytology, characteristic growth patterns in culture, cell size, color in mass, and aggregation structures.