ALBERT

Description: An abrupt lithofacies change between calcareous shale and noncalcareous shale occurs in strata deposited in the mid-Cretaceous Greenhorn Seaway in the southeastern corner of Montana. The facies were correlated lithostratigraphically using bentonites and calcarenites. The lithocorrelations were then refined using ammonites, foraminifera, and calcareous nannofossils. Twenty-five time slices were defined within the upper middle and lower upper Cenomanian strata. Biofacies analysis indicate that lithofacies changes record the boundary or oceanic front between two water masses with distinctly different paleoceanographic conditions. One water mass entered the seaway from the Arctic and the other from the Gulf of Mexico/Tethys. The microfauna and microflora permit interpretation of the environmental conditions in each water mass. At times when the front was near vertical, the two water masses were of the same density but of different temperatures and salinities.

Description: We present ΔA14C and 39Ar data collected in the Nansen, Amundsen and Makarov basins during two expeditions to the central Arctic Ocean (RV Polarstern cruises ARK IV/3, 1987 and ARK VIII/3, 1991). The data are used, together with published Δ14C values, to describe the distribution of Δ14C in all major basins of the Arctic Ocean (Nansen, Amundsen, Makarov and Canada Basins), as well as the 39Ar distribution in the Nansen Basin and the deep waters of the Amundsen and Makarov Basins. From the combined Δ14C and 39Ar distributions, we derive information on the mean “isolation ages” of the deep and bottom waters of the Arctic Ocean. The data point toward mean ages of the bottom waters in the Eurasian Basin (Nansen and Amundsen Basins) of ca. 250-300 yr. The deep waters of the Amundsen Basin show slightly higher 3H concentrations than those in the Nansen Basin, indicating the addition of a higher fraction of water that has been at the sea surface during the past few decades. Correction for the bomb 14C added to the deep waters along with bomb 3H yields isolation ages for the bulk of the deep and bottom waters of the Amundsen Basin similar to those estimated for the Nansen Basin. This finding agrees well with the 39Ar data. Deep and bottom waters in the Canadian Basin (Makarov and Canada Basins) are very homogeneous, with an isolation age of ca. 450 yr. Δ14C and 39Ar data and a simple inverse model treating the Canadian Basin Deep Water (CBDW) as one well-mixed reservoir renewed by a mixture of Atlantic Water (29%), Eurasian Basin Deep Water (69%) and brine-enriched shelf water (2%) yield a mean residence time of CBDW of ca. 300 yr.

Description: The foraging ecology of free—living King Penguins (Aptenodytes patagonicus) was studied during October and November 1991 on Possession Island (46°25' S, 51°45'E), Crozet Archipelago. Feeding was detected with stomach temperature sensors, which logged feeding activity as indicated by temperature drops. The penguins fed mainly on myctophid fish. Stomach temperature of 16 birds at sea was recorded for a total of 146 d. During 125 d a total of 16 474 food ingestion events was recorded, a mean of 132 events per day. Here, calculated food intake averaged 2320 g/d (range 11—12 889 g) with 〉80% (range 71—95%) of prey caught during daylight. During the remaining 21 d stomach temperature dropped below the detection limit of 20°C, which made determination of the number of ingestion events impossible and mass ingested determination inaccurate. We propose that there is selection pressure for King Penguins to ingest and digest large quantities of food quickly because these birds alternate fasting periods on land, during which time they care for their chicks, with foraging trips, during which time they must feed on patchily distributed prey.

Description: The proximate (protein, lipid, carbohydrate and ash) and elemental (C, H, N and P) composition of the major tissues were measured for 18 male and 51 female Illex argentinus sampled from the feeding grounds over the Patagonian Shelf. In most tissues the chemical composition did not vary with sexual maturity, although the mass of the tissue increased significantly because sexual maturation and growth were proceeding simultaneously. The composition of the ovary and associated tissues (nidamental gland, oviducal gland) did change significantly during sexual maturation. Several tissues contained significant amounts of one or more unknown components. The nitrogen content of an unknown component in the testis was similar to that of DNA. In the spermatophoric complex the nitrogen content suggested the unknown fraction may be an amino acid or short peptide, whereas in the nidamental gland the nitrogen content suggested an amino-sugar or polysaccharide derivative. The digestive gland was rich in lipid and continued to accumulate substantial reserves of energy throughout the period of sexual maturation on the feeding grounds. During this period there was no evidence for the utilization of either digestive gland or mantle tissues to supply energy for gonads. Accumulation of carbon and energy (estimated stoichiometrically from carbon) during the final 50 days on the feeding grounds indicated that energy demands for tissue synthesis in females were almost twice those of the smaller males, and that a relatively small fraction of the demands were for reproductive tissues (5% in males, 15% in females). Most energy intake in this period was directed to the digestive gland (40% in males, 47% in females) and other somatic growth (54% in males, 38% in females). A preliminary power budget suggested that during the final days of feeding before migrating to the spawning grounds, energy intake of Illex argentinus is 4-5% body energy content per day, growth efficiencies are low (17-22%) and that energy reserves in the digestive gland would fuel migration in the absence of feeding for 14 days in males and 21 days in females.

Description: Time series (1965-1985) of Illex illecebrosus catch and morphometric data from the Northwest Atlantic were analysed to describe geographic variability in population structure. The areas studied were NAFO sub-areas 3 to 6, which range from Newfoundland to the northeastern USA shelf. Population components, reflecting seasonal spawning groups, were identified based on analysis of length frequency data. Components 3 and 4 represent two prominent life cycles: the summer spawners and winter spawners respectively. Components 1, 2, and 5 do not represent different life cycles, but result from the capacity to shift between life cycles by prolonging (or shortening) the life span. The presence of up to five components in the southern area illustrates a life history strategy involving protracted spawning and complex population structure. There was clear geographic variability in annual catch, with fluctuations being most extreme in the most northern area. Annual catch levels in all areas were significantly correlated with the abundance of the winter-spawning component, as represented by the number of squid within samples which belong to component 4. Population structure in the most northem area was simplest and catch levels therefore were most dependent on the highly migratory winter-spawning component. This leads to greater catch variability in the most northern area than in the other areas. The advantages of good feeding conditions may compensate for the risks associated with long-range migrations, especially recruitment failure. Life history strategies involving migratory and non-migratory population components limit the risk of recruitment failure. The overall resultant life history strategy for Illex illecebrosus is one that ensures survival of the species by stabilizing recruitment in at least one (southern) area through protracted spawning, complex population structure and interaction of spawning components. Time series (1965-1985) of Illex illecebrosus catch and morphometric data from the Northwest Atlantic were analysed to describe geographic variability in population structure. The areas studied were NAFO sub-areas 3 to 6, which range from Newfoundland to the northeastern USA shelf. Population components, reflecting seasonal spawning groups, were identified based on analysis of length frequency data. Components 3 and 4 represent two prominent life cycles: the summer spawners and winter spawners respectively. Components 1, 2, and 5 do not represent different life cycles, but result from the capacity to shift between life cycles by prolonging (or shortening) the life span. The presence of up to five components in the southern area illustrates a life history strategy involving protracted spawning and complex population structure. There was clear geographic variability in annual catch, with fluctuations being most extreme in the most northern area. Annual catch levels in all areas were significantly correlated with the abundance of the winter-spawning component, as represented by the number of squid within samples which belong to component 4. Population structure in the most northem area was simplest and catch levels therefore were most dependent on the highly migratory winter-spawning component. This leads to greater catch variability in the most northern area than in the other areas. The advantages of good feeding conditions may compensate for the risks associated with long-range migrations, especially recruitment failure. Life history strategies involving migratory and non-migratory population components limit the risk of recruitment failure. The overall resultant life history strategy for Illex illecebrosus is one that ensures survival of the species by stabilizing recruitment in at least one (southern) area through protracted spawning, complex population structure and interaction of spawning components.

Description: Finding of some uncommon cephalopods, Ancistroteuthis lichtensteinii, Histioteuthis bonnellii, H. reversa and the first record of Chiroteuthis veranyi in the Ionian Sea are reported here. Data were collected during a trawl survey carried out on red shrimp grounds during August 1993.

Description: Four research surveys of Falkland Island waters were carried out to determine the distribution and abundance of the early life-history stages of Loligo gahi (d'Orbigny, 1835) in the austral winter of 1988 and the austral springs of 1990, 1991 and 1992. Juveniles were caught during three of the four surveys in both Bongo nets and an RMT8 net. In each case, greatest numbers were consistently caught in waters of ≤100 m to the south and east of East Falkland. The use of an opening/closing net in 1992 showed that most L. gahi juveniles aggregate close to the sea floor and are more available to the sampling gear by night than by day. Limited temperature data for the 1991 and 1992 surveys suggest that distribution on the coastal shelf may be associated with water-column structure. In 1992 when temperature data implied a mixed water column, juveniles were caught in deeper water than in 1991 when the water column was stratified. The results suggest that the spawning grounds of L. gahi are probably situated to the south and east of the Falkland Islands, at least for squid hatched in the austral winter/spring.

Description: The periodicity of deposition of growth increments in the cuttlebone of juvenile Sepia officinalis was investigated under controlled conditions for a short period after hatching (19 days). The slope of time elapsed and increment counts was significantly different from 1 indicating that lamellae are not deposited on a daily basis. The relationship between increment counts and juvenile length was, however, highly significant. Also significant were the relationships between the number of growth increments and shell length and increment counts and cuttlebone area. These data show that the number of growth increments is related primarily to the growth rate of the juvenile rather than to its chronological age. Taking into account these data, the cuttlebone lamellae cannot be used for age determination in the juvenile cuttlefish just after hatching.

Description: In der letzten Ausgabe der "Mitteilungen zur Kieler Polarforschung" habe ich über die Gefrierschutzproteine bei Pleuragramma antarcticum berichtet. Dabei habe ich unter anderem ein bislang unbekanntes Glykoprotein vorgestellt, welches nur bei dem antarktischen Silberfisch nachgewiesen werden konnte. Heute möchte ich auf die anderen Arten des Weddellmeeres und Lasarewmeeres eingehen, die ich im Rahmen meiner Promotion auf den Gefrierschutz hin untersucht habe ( WÖHRMANN & ZIMMERMANN 1992; WÖHRMANN 1993).

Description: Die resultierende Kraft aus dem Kräftedreieck Fischerei. Fischereiforschung und Fischereiverwaltung soll die nachhaltige Nutzung mariner und limnischer Fischbestände sichern. Der Informationsfluß von der Forschung (Wissenschaft)über das Management (Politik) zur Administration (einschl. Kontrolle) soll die Fischerei nach wirtschaftlichen und populationsdynamischen Kriterien steuern. Da weltweit zahlreiche Fischbestände zusammengebrochen sind, stellt sich die Frage, warum das System versagt hat. Warum schaffen wir, die wir regeln wollen, keine Ordnung in der Fischerei?

Description: The holoplanktonic family Miraciidae (Copepoda, Harpacticoida) is revised and a key to the four monotypic genera presented. Amended diagnoses are given for Miracia Dana, Oculosetella Dahl and Macrosetella A. Scott, based on complete redescriptions of their respective type species M. efferata Dana, 1849, O. gracilis (Dana, 1849) and M. gracilis (Dana, 1847). A fourth genus Distioculus gen. nov. is proposed to accommodate Miracia minor T. Scott, 1894. The occurrence of two size-morphs of M. gracilis in the Red Sea is discussed, and reliable distribution records of the problematic O. gracilis are compiled. The first nauplius of M. gracilis is described in detail and changes in the structure of the antennule, P2 endopod and caudal ramus during copepodid development are illustrated. Phylogenetic analysis revealed that Miracia is closest to the miraciid ancestor and placed Oculosetella-Macrosetella at the terminal branch of the cladogram. Various aspects of miraciid biology are reviewed, including reproduction, postembryonic development, vertical and geographical distribution, bioluminescence, photoreception and their association with filamentous Cyanobacteria (Trichodesmium).

Description: It has long been recognized that global Pleistocene-Holocene material fluxes are qualitatively distinct from those of the earlier Cenozoic and Mesozoic, but the full extent of the differences has only recently begun to emerge. Quantitative estimates of the masses of material eroded, transported, and deposited during the Pleistocene-Holocene have been difficult to obtain because of the lack of consistent information on the thicknesses and areal extent of the deposits on land and in shallow seas. Geologic maps commonly show extensive areas of Quaternary cover on older sediments, but information on the thickness of the tills, alluvium, and colluvium that make up these deposits is scattered throughout the literature and is often incomplete.

Description: Artificial selection processes associated with harvesting may operate over relatively short time scales in short-lived semelparous species. The ommastrephid squid Illex argentinus on the Patagonian Shelf is the target of a major fishery. Recent work has provided new information on the biological characteristics of squid in this fishery. That information has been utilized in the development of a model of the cohort dynamics and some of the within-seasons selective effects considered. The model results are consistent with earlier data from the shelf fisheries, supporting suggestions that the males nature and migrate earlier towards the spawning grounds than the females. Earlier maturation results in a smaller mean size in the spawning stock, while later maturation results in greater exposure to the fishery and a reduced numbers of individuals surviving to spawn. Under the current fishing regime greater egg production and a larger spermatophoric complex mass for the whole cohort is achieved by relatively late maturation. In general, however, the earlier maturation occurs, the earlier is the peak in total egg production. The within-season pattern of effort expenditure in the fishery can affect not only yield from the fishery but also the reproductive potential of the spawning stock. The management policy adopted for this fishery is likely to be conservative in terms of maintenance of a spawning stock, however, the potential for selective effects is larger and this may affect both yield and reproductive potential. The results are discussed in relation to short- and long-term effects in the fishery and the implications for future research requirements.

Description: The main squid species of commercial importance in the northern NE Atlantic is the veined squid Loligo forbesi. The present paper reviews trophic interactions involving this species in Scottish waters. Loligo forbesi is primarily piscivorous, although the diet also includes crustaceans and there is some cannibalism. In 1990/91, the Scottish population may have eaten 9000-16 000 tonnes of food, including 1700-3000 tonnes of sandeels (Ammodytidae), a similar amount of Trisopterus spp. and 1000-1700 tonnes of whiting Merlangius merlangus. Loligo forbesi is eaten by various predatory fish, seabirds and marine mammals. Harbour seals Phoca vitulina and grey seals Halichoerus grypus eat Loligo in small amounts. Loligo forbesi is more important in the diets of harbour porpoise Phocoena phocoena. These three mammal species alone may remove more squid from Scottish waters every year than the commercial fishery. The importance of Loligo forbesi in fish and seabird diets is not well documented, although many studies indicate that other squid species are eaten.

Description: Demersal trawl and dredge surveys in 1990 and 1991 recorded taxa (comprising 5 loliginid squids, 7 cuttlefishes, 7 octopuses and 2 dumpling squids). In addition to hosting species distributed broadly in the Indo-West Pacific, the Gulf of Carpentaria represents the most north-westerly extent of the range of some eastern Australian species. Squid catches were lower in the north-western gulf in 1990 and higher in shallower water during the more geographically restricted survey in 1991, whereas cuttlefish were more evenly distributed throughout the different sampling areas in both years. Cephalopods are a minor component in reported domestic fisheries catches where penaeid prawns are targeted. High (though seasonal) squid catch rates were reported annually by Taiwanese trawlers targeting butterfish and squid from certain areas prior to 1979. With the observed population structure of the abundant cephalopod species and relatively high catch rates in some localities during these recent surveys, it is suggested that the cephalopod resources of the Gulf of Carpentaria could support increased commercial fisheries exploitation.

Description: A microphytobenthic species composition of a tidal flat in the northern Wadden Sea was analysed regarding cell numbers and biomass (in carbon units). The three sampling sites differed in tidal inundation from 15 cm to about 90 cm water depth at high tide. The sediment was sandy at all three stations. A cluster analysis revealed a separation of the benthic diatoms into three areas: aNereis-Corophium-belt, a seagrass-bed and theArenicola-flat. Small epipsammic diatoms were most abundant and dominated the microalgal biomass. A microphytobenthic “spring bloom” even started beneath the ice cover of the flat in January. Lowest values of cell numbers and biomass of benthic microalgae were found in summer. Highest values were measured in the uppermost area (Nereis-Corophium-belt), and only here was an autumnal increase of benthic microalgae found. Further cluster analysis within each of the three areas revealed seasonal differences although the majority of species were present all year round. Many species were most abundant in spring, and some showed a bimodal distribution (spring-autumn) in the year of investigation

Description: Prey availability is one of the factors determining the distribution of seabirds at sea. Northern fulmars Fulmarus glaclalis and black-legged kittiwakes Rissa tridactyla were the most regular and frequent ship-followers across the central and northern North Sea during 2 surveys with a fishery research vessel in May-June and July-August 1992. Sixteen other species occurred less often and/or in lower numbers. Birds consumed 84 % of experimentally discarded roundfish and 8 % of discarded flatfish. On average, northern gannets Morus bassanus took the largest individuals of most fish specles, black-legged kittywakes the smallest The average size choices of herring gulls Larus argentatus, lesser black-backed gulls Larus fuscus and northern fulmars lay between these 2 extremes. The choice of fish lengths by birds vaned with different fish species. Northern gannet was the most successful species in consuming discards. Northern fulmars success rates decreased with the presence of larger ship-followers but were never high. Black-headed gull Larus ridibundus and common gull Larus canus were less successful than the more frequent typical ship-following species.

Description: The influence of ambient temperature (2-7°C) and oxygen level (1.0-8.3 ml· l- 1) on the development of Baltic cod eggs was investigated in laboratory experiments. The incubation period, i.e. the time from fertilization to 50% hatching, decreased from 27.5 days at 2°C to 13.0 days at 7°C. Reduced oxygen levels did not significantly affect the time of hatching. Throughout the incubation period highest mortality rates were found during gastrulation and immediately prior to hatching at all tested oxygen levels. Egg survival decreased from around 30% at an oxygen level of 8 ml· 1- 1 to less than 10% at 2 ml· 1- 1 oxygen content. At oxygen concentrations below 2 ml 0 2 • l- 1 the development ceased at a very early stage. Field observations revealed that in the past years Baltic cod eggs were most abundant below the halocline, depth with unfavourable oxygen condition. Besides the effect on egg survival, low environmental oxygen may also affect the initial viability of larvae and consequently their ability to approach the feeding areas close to the sea surface. Thus, the effective reproduction volume of water for cod in the central Baltic may have been smaller than expected and it is suggested that oxygen depletion was the limiting factor determining the reproductive success of cod in this area during the last decade.

Description: The levels of four trace metals (Cd, Cu, Pb, and Zn) in the whole soft body and in different organs of the ocean quahog Arctica islandica were evaluated from four stations in Kiel Bay, Western Baltic. The relationships between the contents and concentrations of these metals and body size (weight and length) were also investigated. Double logarithmic plots of metal contents and concentrations against dry body weight and shell length, respectively, show straight-line relationships. The results indicate that smaller individuals have higher concentrations of Cu and Zn, two essential metals, while larger individuals have higher concentrations of Cd and Pb, two non-essential metals. The calculated regression slopes of metal content against dry-body weight revealed that Cd and Cu appear to be affected by maturation since two different slopes are observed for both metals before and after maturation. This was not obvious for Pb and Zn. Pooled slopes of metal content against dry-body weight for all animal sizes indicated that Cu and Zn have a one common slope of (0.82) and Cd and Pb another common one of (1.51). Plots of metal concentrations against shell length indicated also that Cu and Zn have one common slope of (−0.54) and Cd and Pb another one of (1.56). Moreover, it was possible to calculate one final slope of (1.53) for Cd and Pb from both content/weight and concentration/length plots. This indicates that A. islandica may have one metabolic strategy for the essential metals and another for the non-essential metals.

Description: The aim of the present study is to develop an efficient assimilation scheme suitable for assimilating satellite altimeter data into a basin-scale eddy-resolving primitive equation model with active thermodynamics. Two alternative methods, referred to as extended nudging and re-initialization, respectively, will be presented and intercompared. The first approach essentially extrapolates the surface observations into the ocean interior using a priori correlations provided by the model climatology. In contrast, the second assimilation procedure emphasizes dynamical relationships and in particular the conservation of temperature and salinity on isopycnals, rather than relying heavily on uncertain statistical correlations. Both methods are tested and found to perform about equally well by running identical twin experiments, in which the model is assumed perfect and generates its own data for assimilation. Twin experiments are further used to compare the assimilation of the altimeter data directly along the satellite ground tracks with the assimilation of preprocessed maps combining all the data within some chosen time window. The results of these experiments indicate that - as far as the assimilation techniques proposed in this study are concerned - assimilation of quasi-synoptic maps is preferential. The actual assimilation experiments are performed with objectively analyzed sea surface height anomalies measured by the U.S. Navy's satellite GEOSAT. Adding the model's mean sea surface to obtain an estimate of absolute dynamic sea level, these maps are then assimilated into the WOCE (World Ocean Circulation Experiment) CME (Community Modelling Effort) model of the North Atlantic Ocean at 5-day intervals covering the year 1987. While the results of the two alternative assimilation procedures were almost indistinguishable in the identical twin experiments using simulated data, marked differences emerge when real altimeter data are used. These differences are shown to arise from different physical and statistical implications of the two assimilation methods. It turns out that a correct treatment of water mass properties is of crucial importance for the success of the assimilation scheme. Only the re-initialization method, which explicitly conserves temperature and salinity on isopycnals, leads to reasonable hydrographic situations, whereas the extended nudging scheme, that uses statistical correlations to infer temperature and salinity from sea surface height measurements, is found to introduce completely unrealistic water masses.

Description: We have used a new General Circulation Model, GENESIS Version 1.02, derived from the U. S. National Center for Atmospheric Research Community Climate Model I (NCAR-CCM I) to simulate the climate of an Earth with realistic Pangaean geography. The climate model was run assuming that the ocean heat flux was similar to that of today, atmospheric C02 content was four times that of today, the solar constant was 2 % less than today, and the Earth's orbit was circular, with mean obliquity 23.4°. Models were run for paleogeographies at 245 Ma (Scythian) and 225 Ma (Carnian). The results indicate that no ice cap would develop over the land, and there is no permanent sea ice. The seasonal temperature Variation in the interior of the continent is in the order of 50 °C. The Continental areas are very dry except for a few Coastal areas and along uplifts. The models both suggest an extreme seasonal monsoonal circulation, with strong westerly winds parallel to the entire coast of Gondwana and the east coast of Laurasia during the northern hemisphere summet. In both hemispheres, the effect is to cause coastal upwelling. The model also predicts permafrost in the deeper soil layers poleward of 50° N and S. The effects of topographic uplifts on the atmospheric circulation are pervasive. Topography strongly affects the monsoonal circulation causing major deviations of the wind Systems suggested in model runs with idealized geographies. Topography also plays a crucial role in concentrating rainfall in a few small areas. It is evident that in order to have a realistic Simulation of paleoclimate, an accurate representation of the paleotopography is essential. It is also evident that the paleoclimate models may be useful in suggesting geological criteria that can confirm or reject the predicted paleoclimatic conditions.

Description: The data presented provides new information on the distribution of Antarctic squids and on the summer diet of the emperor penguins. The diet of 58 adult emperor penguins (Aptenodytes forsteri) on the fast ice of the Drescher Inlet, Vestkapp Ice Shelf (72°52′S, 19°25′W) in the eastern Weddell Sea was investigated. Prey consisted principally of squid, fish, krill, amphipods and isopods. Squids were identified by the lower beaks and allometric equations were used to estimate the squid biomass represented. Beaks occurred in 93% of the stomach samples. Each sample contained a mean of 27 beaks (range 1–206). Ninety-two percent of the squids could be identified by the lower beaks and belonged to four families (Onychoteuthidae, Psychroteuthidae, Neoteuthidae and Gonatidae). The most abundant squid was Psychroteuthis glacialis which occurred in 52 samples with lower rostral lengths (LRL) ranging from 1.4–7.2 mm. Forty-five samples contained Alluroteuthis antarcticus (LRL range 1.8–5.8 mm), 17 Kondakovia longimana (LRL range 4–12.1 mm), and four Gonatus antarcticus (LRL range 4.1–6.1 mm). In terms of biomass K. longimana was the most important species taken by the penguins comprising 50% of total estimated squid wet mass (245348 g) in 1990 and 48% in 1992 (154873 g). However, if only fresh beaks were considered for estimations of squid consumption, i.e. beaks that have been accumulated for not longer than 5–6 days in the stomachs, squid diet was of minor importance. Then total squid wet mass accounted for only 4809 g in 1990 and 5445 g in 1992 which implies that one penguin took c.30 g squid d−1 with P. glacialis and A. antarcticus being the most important by mass. The prey composition suggests that emperor penguins take squid at the steep slope regions of the eastern Weddell Sea.

Description: Ninety-three species of bony fishes were caught in 4 seasonal bottom-trawl surveys carried out between July 1986 and May 1987 on the outer shelf and upper slope (124 to 587 m depth) along the southern Brazilian coast (30°40' to 34"30' S). On the outer shelf (〈 179 m), the demersal- pelagic species Trichiurus lepturus, Trachurus lathami, Cynoscion guatucupa, Scomber japonicus, and Thyrsitops lepidopoides predominated and also to a lesser degree the demersal benthonic Umbrina canosai and Mullus argentinae. Antiyonia capros and Priacanthus arenatus were found associated with the relic coral hard bottoms of the shelf break (180 to 249 m). Further offshore, the demersal-pelagic species Ariomma bondi and Zenopsis conchifera and the demersal benthonic species Polyprion ameri- canus and Helicolenus lahillei were abundant, both associated with rocky bottoms. The macrourids Coelorinchus marinii and Malacocephalus occidentalis characterized deep-water hauls p450 m). Frequent and widespread, but less abundant in the catch, were Polymixia lowei, Urophycis mystacea and Merluccius hubbsi. Mean total catch (kg h-') decreased 6-fold and the number of species by more than half along the depth range, with a sharp step at 350 m. Both catch and number of species were slightly higher in the winter cruises. Most species occurred in both winter and summer-autumn cruises, but, with increasing depth, the relative abundance of species that occur year-round decreased, whereas fishes that occur mostly in winter increased. The catch of demersal-pelagic fish decreased sharply below 350 m and differed little among seasons; catches of demersal-benthonic fish were more evenly distributed across the depth range and were larger in winter and spring. The high number of species on the shelf break may be attributable to the higher variety of soft and consolidated substrates and the overlapping of different water masses along the water column. The north-south shift of the western boundary of the Subtropical Convergence appears to be mainly responsible for the seasonal changes in abundance of the species.

Description: Fifty-nine specimens of the tropical epipelagic eno-ploteuthid Enoplotcuthis leptura were collected in the central-east Atlantic between 1986–1988. Statoliths were extracted from all specimens (mantle length (ML) 4.1–92 mm) and processed under the statolith ageing technique. The characteristic feature of statolith morphology in E. leptura is a sculpture of the rostrum, which is covered by numerous tiny spines and knobs. In the ground statolith it was possible to distinguish four main growth zones consisting of narrow growth increments like those in other squids studied. Allometric growth of statoliths versus ML is negative. E. leptura is a short-lived squid with a half-year life span. Growth rates of E. leptura are high at juvenile stage (instantaneous rate of growth (G) of body weight (BW) 0.04–0.06). An early maturation of males (at age 45–60 days) and females (at 80–90 days) causes a sharp decrease of somatic growth of E. leptura, and mature squid have low growth rates (G of BW - 0.OO3-O.0O5). Spawning takes place between January and September with two peaks: in January and in June-July.

Description: Whether the study of external morphology can increase our knowledge of shallow-water octopuses and their biology is tested by multivariate morphometric analyses. The extent of morphological variation among 20 species from the Atlantic and eastern tropical Pacific Oceans is explored, and four hypotheses are addressed: (1) that octopuses show secondary sexual dimorphism; (2) that remote, ostensibly conspecific populations are morphologically distinct; (3) that morphometric characters contribute to resource partitioning among sympatric species; and (4) that morphology is predictably associated with habitat. Results of principal components analysis show most species to be very similar in shape. Arm length contributes most shape variation; other characters contribute little. Principal components and size-free discriminant analyses refute each of the hypotheses considered. The morphological similarity of isolated Atlantic populations may be a symplesiomorphy, but information on the planktonic phase of the octopus lire cycle supports the possibility of dispersal across the Atlantic Ocean. Size, not directly treated here, may significantly affect some aspects of octopus biology. Increased female size may evolve due to selection for increased fecundity and intraspecific niche partitioning. Size may also indicate interaction within and among species. Characters of shape, deemed essential to species descriptions, do not appear to be able to identify most specimens, nor to increase our understanding of octopus biology.

Description: A total of 40 (29 female and 11 male) Ross seals were sampled in January over three years. Seals were weighed, measured and age determined by counting dentine lines in teeth. Stomach contents were identified against reference material and species of helminths were determined using standard techniques. Asymptotes in body mass and length are reached at some nine years of age. Age class varied from 2–20 years. Antarctic silverfish Pleurogrammma antarcticum was the only fish species identified. Psychroteuthis glacialis dominated the squid component. Fish was dominant in three samples, squid was the exclusive component in two samples and a minor component in another two. Glandicephalus antarcticus, Diphyllobothrium wilsoni and Contracaecum spp were the dominant helminths present. The high proportion of empty or nearly empty stomachs conforms with the knowledge that this species moults and consequently fasts in January.

Description: A collection of juvenile squid were caught with the Isaacs-Kidd midwater trawl (IKMT) and the Juday plankton net at 86 stations in Prydz Bay (60°–67°30′S, 60°–80°E) to a depth of 500 m but mostly at 0–200 m. Five species were identified, Psychroteuthis glacialis, Alluroteuthis antarcticus, Brachioteuthis sp. and the cranchiids Galiteuthis glacialis and Mesonychoteuthis hamiltoni. P. glacialis and the cranchiids were the most abundant species. Young P. glacialis (5–17 mm ML) were taken at depths of 5–200 m but concentrated in the upper 100 m whilst the cranchiids (5–35 mm ML) occurred over a wider vertical range (50–500 m). The regular occurrence of paralarvae and juveniles suggests that all the species reproduce in the Antarctic. Juvenile Vertical distribution appears to differ between species with P. glacialis concentrated relatively near the surface, the cranchiids in the upper part of the Circumpolar Deep Water and A. antarcticus widely distributed to a depth of 900 m.

Description: The stomach contents of 723 Loligo vulgaris and 440 Loligo forbesi caught in the northwestern Spanish Atlantic waters have been examined. The diets of both species are described and compared. Loligo vulgaris shows 28 different types of prey belonging to four groups (Teleostei, Crustacea, Cephalopoda and Polychaeta) and Loligo forbesi 27 different types of prey belonging to three groups (Teleostei, Crustacea and Cephalopoda). Both species catch similar prey species but in different proportions. Cannibalism was observed in both species. Estimated prey sizes were smaller than squid sizes. No differences in feeding habits of males and females of both species were observed, but females seem to increase food intake during maturation. No significant changes were found in the diet of Loligo vulgaris within the size (DML) range studied (65–465 mm). Importance of cephalopods increased and importance of fish decreased in the diet of Loligo forbesi with growth (65–685 mm). Diet and food intake varied with seasons in both species. Diets of both squids were significantly different. Los contenidos estomacales de 723 Loligo vulgaris y 440 Loligo forbesi capturados en aguas de Galicia (Noroeste de España) fueron examinados. Se describe y compara la dieta de ambas especies. Se identificaron 28 tipos de presa diferentes en Loligo vulgaris que pertenecen a cuatro grupos (Teleostei, Crustacea, Cephalopoda y Polychaeta); y 27 tipos de presa en Loligo forbesi, pertenecientes a tres grupos (Teleostei, Crustacea y Cephalopoda). Ambas especies comen pres as similares, pero en proporciones diferentes. En ambas especies se observó canibalismo. La talla de las presas fue menor que la de los calamares. No se encontraron diferencias en la dieta entre machos y hembras en ambas especies, pero se observó que las hembras incrementan su tasa de ingestión durante la maduración. No se hallaron cambios significativos en la dieta de Loligo vulgaris en función de la talla (DML) dentro del rango de tamanos estudiado (65–465 mm). En Loligo forbesi, los cefalópodos aumentaron y los peces disminuyeron en importancia con la talla (65–685 mm DML). La dieta y la tasta de ingestión de ambas especies varió con la época del ano. Las dietas de ambas especies fueron significativemente diferentes entre sí.

Description: A simple method of providing a regular supply of live food for the experimental culture of paralarval cephalopods is described. The primary food source utilized was hatched zoeae of large laboratory populations of the hermit crab, Pagurus prideaux. Zoeal size, swimming behaviour, and distribution in the water column make these zoeae a suitable live prey for rearing early post-hatching planktonic stages of cephalopods and probably other marine zooplanktivores. Ovigerous P. prideaux females were collected from the sea throughout the year at depths between 10 and 90 m in the NW Mediterranean and maintained at densities of up to 500 specimens · m−2. One month after spawning in aquaria, 38% of the females of P. prideaux started to incubate a second clutch of eggs. Other decapod crustacean species, such as Liocarcinus depurator and Dardanus arrosor, were maintained to use their zoeae as a food source for cephalopod paralarvae. P. prideaux zoeae were used as the sole or main food resource for rearing Loligo vulgaris and Octopus vulgaris, during the first 2 months of life. First feeding and initial growth in L. vulgaris and O. vulgaris paralarvae can be successfully stimulated using decapod zoeae with a total length equivalent to 50–100% of the cephalopod's mantle length.

Description: Various systematic and phylogenetic relationships have been proposed for extent decapod Cephalopods, based mainly on morphology and on the rare paleontological remains. Nucleotide sequence data from the 3' end of 16S rDNA gene were used as an alternative approach to morphology; this gene portion having proved to be appropriate to test divergences in other groups of assumed equivalent age. The results from 27 Decapoda species allowed us to calculate phylogenetic trees by the neighbor joining and parsimony methods (Paup and Hennig86). The trees were submitted to bootstrapping. The order Sepioidea, including the sepiids, sepiolids and spirulids, is not supported by molecular evidence. Sepiolids are clearly excluded from the order, and the position of the Spirulidae needs further clarification. In oegopsids, the intrafamilial groupings obtained by the molecular approach is in agreement with morphological data. The unresolved phylogeny at the suprafamilial level might be the result of two different events: earlier divergence than the Cenozoic, or unequal evolutionary rates among taxa having appeared either by successive emergence or by fast radiation. The 3' end of 16S rDNA gene of cephalopods is a precious tool to analyze taxonomic relationships at the infrafamilial level. A gene with a lower evolutionary rate, is necessary to establish higher taxa phylogeny.

Description: Available knowledge is reviewed and new data incorporated in a synthesis of the life history and ecology of the chokka squid Loligo vulgaris reynaudii. We attempt to show that these aspects are essential to rational management of the resource. The life cycle is descriptionbed in detail from the egg to adult stage, mainly in biological terms, including a comprehensive descriptionption of maturation, migration and reproduction. Possible ecological interactions, particularly those of paralarvae and copepods, are discussed. Predator-prey relationships and the current state of knowledge on the effect of the physical environment on squid availability and abundance are summarized.

Description: As long as salinity in the Baltic Sea was high (as it was between 1948 and 1982) the depth range between 70 and 100 m suffered frequent anoxia. However, when salinity was low and when the position of the halocline was deep (as it was in the first half of the century) oxygen conditions were good and long-lived macrofauna occurred. Should the present trend to lower salinities continue (building bridges across the Belt Sea and reducing salt water inflow would be helpful) one can foresee a recolonization by macrofauna in the depth range 70–100 m.

Description: The investigation was perfo1med on a stable population of the edible Iceland Scallop Chla111ys islandica (Millier) in the subarctic Balsfjord, Tromsi:i, Northern Norway. 470 Chla111ys specimens were collected and dry weight of the soft parts and of the shell, height of the shell, age of the animal and number of holes bored into each valve were determined. The population was found to be heavily infested by the boring sponge Cliona vast(fica Hancock, which is here close to its northern distribution limit. Nearly 90 % of all scallops had borings in their shells. Only specimens with an age of 3 years and less and a shell height of 35 mm or less were not infested. 100 % of scallops aged 16 years or more harbour C. vastifica in their shells. The average degree of infestation as judged by number of borings in the shell increases with age. However, statistical analysis of the relation of number of borings to both scallop body mass and shell weight at certain shell sizes indicates that C. vastifica does not impair the development of its substrate clams. The reason for this is the high growth rate of Chla111ys islandica in a fully suitable habitat and the comparatively low growth rate of Cliona vast(fica living close to the limit ofits geographical distribution; this long-term coexistence may represent a subtle balance between the commensalistic boring sponge and substrate bivalve hardly possible in warmer areas.

Description: Juveniles of the common dentex (Dentex dentex) (2.4 g mean weight), were grown over a 6 week period, fed exclusively on a commercial sea bream diet or an isocaloric moist pellet diet, which was produced on site. Ambient temperature (24.4-26.2 °C) and oxygen content (4.8-5.9 mg/L), as well as the relatively low stocking density (max. 2.62 kg/m3) provided favourable rearing conditions. Survival (63.8% vs 51.6%), specific growth rates (6.1% vs 4.5%) and food conversion efficiency (115.8% vs 76.3%) were considerably elevated in the group fed on moist pellets. The growth performance parameters recorded are considered to be favourable for aquaculture requirements. Agonistic behaviour (particular biting of the tail) was found to be the main cause of the continuous mortality that occurred in both feed groups (78% and 64.8% of total mortality in the dry- and moist-pellet group, respectively). These biting attacks targeted the smallest individuals in a tank, whose mean individual weight made up 49-62% (with dry pellet diet) and 28.9-46.6% (with moist pellet diet) of the respective mean weights. The results indicate a strong relationship between nutrition, size variation and agonistic behaviour in the rearing of cornmon dentex juveniles.

Description: Eider, Somateria mollissima, and mussel, Mytilus edulis, stocks were studied in the Wadden Sea of Schleswig-Holstein with respect to interactions with mussel fisheries. Mussel fisheries take place by means of 2,800 ha of bottom cultures, with seed mussels taken from natural beds. Fisheries have a marked influence on total mussel stocks. The amount of mussels found on the culture lots and annual landings of up to 40,000 tons may exceed natural stocks. About 130,000 eiders use the Wadden Sea of Schleswig-Holstein for moulting and on average about 70,000 stay over the winter. Mussel cultures are estimated to provide on average about 10 to 20% of the food of eiders. However, the number of wintering eiders utilizing the cultures varies in relation to the amount and size of the mussels present and ranges from 10 to 60%. No evidence was found that eiders have a measurable impact on the yield of the cultures and no response of eider numbers to increasing culturing could be detected. Mussel fisheries are regarded as a potential threat to eiders, because they might reduce total mussel stocks considernbly and might affect eider numbers in years of low bivalve stocks. It is recommended to regulate the fisheries in order to prevent overfishing of mussel stocks, which recently happened in other parts of the Wadden Sea.

Description: The reproductive cycle of the sponge Halichondria panicea was investigated at Boknis Eck in the Western Kiel Bight over 2 yr, and over 1 yr on the island Helgoland in the North Sea and was compared with material collected earlier at Tjärnö at the Swedish west coast. Temperature and salinity were monitored at the different stations in order to determine whether different hydrographic conditions could be linked to differences in seasonal patterns of the reproductive cycle. The results showed H. panicea to be gonochoristic at all stations. The ratio of males to females varied between populations and years, but females predominated consistently. Comparison of the reproductive cycle in the years 1987 and 1989 at the brackish-water station Boknis Eck shows that high ambient winter and spring temperatures in 1989 resulted in a shorter period of oogenesis and earlier larval release, as compared to the year 1987. The reproductive cycle of the sponges at the fully marine station at Helgoland in 1989 and the brackish-water station at Tjärnö in 1978 under temperature and salinity conditions similar to those at Boknis Eck in 1989 showed the same seasonal pattern. We conclude that the lower salinities found at both Boknis Eck and Tjärnö do not cause a delay or slow-down of reproduction at these stations as compared to Helgoland. Under favourable temperature conditions, oogenesis was highly synchronous within the different populations, while it was more spread over time under the low ambient water temperatures at Boknis Eck in 1987.

Description: The zonal monsoon circulation south of India/Sri Lanka is a crucial link for the exchange between the northeastern and the northwestern Indian Ocean. The first direct measurements from moored stations and shipboard profiling on the seasonal and shorter‐period variability of this flow are presented here. Of the three moorings deployed from January 1991 to February 1992 along 80°30′E between 4°11′N and 5°39′N, the outer two were equipped with upward looking acoustic Doppler current profilers (ADCPs) at 260‐m depth. The moored and shipboard ADCP measurements revealed a very shallow structure of the near‐surface flow, which was mostly confined to the top 100 m and required extrapolation of moored current shears toward the surface for transport calculations. During the winter monsoon, the westward flowing Northeast Monsoon Current (NMC) carried a mean transport of about 12 Sv in early 1991 and 10 Sv in early 1992. During the summer monsoon, transports in the eastward Southwest Monsoon Current (SMC) were about 8 Sv for the region north of 3°45′N, but the current might have extended further south, to 2°N, which would increase the total SMC transport to about 15 Sv. The circulation during the summer was sometimes found to be more complicated, with the SMC occasionally being separated from the Sri Lankan coast by a band of westward flowing low‐salinity water originating in the Bay of Bengal. The annual‐mean flow past Sri Lanka was weakly westward with a transport of only 2–3 Sv. Using seasonal‐mean ship drift currents for surface values in the transport calculations yielded rather similar results to upward extrapolation of the moored profiles. The observations are compared with output of recent numerical models of the Indian Ocean circulation, which generally show the origin of the zonal flow past India/Sri Lanka to be at low latitudes and driven by the large‐scale tropical wind field. Superimposed on this zonal circulation is local communication along the coast between the Bay of Bengal and the Arabian Sea

Description: The climates of two realistic geographic representations of the Triassic earth, corresponding in age to the Scythian (245 Ma) and the Carnian (225 Ma), are explored using a new atmospheric general circulation model (AGCM) called GENESIS. The GENESIS AGCM is coupled to a slab ocean 50 m thick, with prescribed heat transport; it also incorporates three types of cloud cover and new models for vegetation effects, soil hydrology, snow cover, and sea-ice formation and melting. Boundary conditions prescribed in the separate Scythian and Carnian experiments include realistic paleogeography and estimates of paleotopography, solar insolation, atmospheric CO2 concentration, vegetation and soil types, and oceanic heat flux. Seasonal simulations of Triassic climate were performed using a horizontal spectral resolution of R15 (4.5 degrees latitude by 7.5 degrees longitude) and 12 levels in the vertical for the atmosphere and 2° × 2* for the surface. Results for both time intervals suggest that most of the seasonal precipitation fell on major highland areas of Pangea. Dry continental climates with very large seasonal temperature ranges (〉45°C) were modeled in the dominantly lowland interior of Pangea. Carnian continental climates predicted by the AGCM were wetter than those of the Scythian; however, both time intervals were characterized by strongly monsoonal circulation. Comparison of these results with lithologic and fossil proxy climatic indicators suggests reasonably good correlations. However, the extreme temperature variations predicted for both Scythian and Carnian are somewhat difficult to reconcile with the fossil record, although accurate interpretation of fossil proxy climatic indicators is not a simple matter. Additional AGCM sensitivity studies may be necessary to resolve this problem.

Description: During a study based on catches taken in the northern North Sea by selected Scottish fishing boats during 1985–1992, large numbers of the normally rare short-fin squid, Todaropsis eblanae (Cephalopoda: Ommastrephidae), were recorded in 1987 and 1990. Our findings, supported by data obtained from plankton/young fish surveys in 1988 and 1989, suggest that in northern waters Todaropsis eblanae generally mates and spawns during late summer and early autumn (June-November). Successful hatching events appear to occur during October-March, producing juvenile (stage I) squid in the early part of the year (January-June). Estimations of maximum male reproductive output and female fecundity were up to 130 spermatophores and ~28,000 eggs per individual, respectively.

Description: The relatively small numbers of pelagic cephalopods caught in the RMT-8 samples (0–300 m) in February/March 1983 in the Weddell Sea were dominated by early life stages of the cranchiid squid Galiteuthis glacialis. A total of 48 specimens were caught with dorsal mantle length (ML) ranging from 4–36 mm. They occurred with a mean density of 0.15 ind. × 1000 m−3 and were present in 38% of 33 RMT-8 samples. G. glacialis was the only cranchiid squid found in the Weddell Sea between 66° and 74°S. Its early life stages were concentrated in the layers below the summer thermocline (〉50 m) and body sizes appeared to increase towards deeper water layers. For biochemical analyses, nine specimens of G. glacialis (ML 6–18 mm) were sampled in the eastern Weddell Sea between 185–520 m water depth in January/February 1985. Total lipid contents ranged from 8%–11% dry weight (DW) with phospholipids being the main lipid component (43–56% of total lipid). Storage lipids (triacylglycerols) made up 18–26% of total lipid. The relatively low lipid contents may reflect the early development stage of the specimens examined. The data presented give the first information on geographical and vertical distribution patterns of early life stages of G. glacialis in the high-Antarctic Weddell Sea, as well as on their lipid content and composition.

Description: his paper analyses the helminth fauna of the flying squid Illex coindetii (Vérany, 1839) collected from natural stock off Galician shelf waters (NW Spain). Aspects of the morphology of the parasites and the host status of squid harbouring intestinal helminth larvae are discussed. RESUMEN: HELMINTOFAUNA DE Illex coindetii (CEPHALOPODA: OMMASTREPHIDAE) EN LAS COSTAS DE GALI-CIA. — En el presente trabajo se analiza la helmintofauna de la pota Illex coindetii (Vérany, 1839) procedente de un stock poblacional en aguas de la plataforma Gallega (NO España). Se discuten ciertos aspectos de la morfología de éstos parásitos y el papel de ésta especie en los ciclos vitales de los helmintos larvales examinados.

Description: Geographic variation in the squid Loligo forbesi was investigated using multivariate analysis of morphometric and meristic characters in samples of squid taken from 13 localities in the Northeast Atlantic Ocean. Two character sets, body morphometrics and beak morphometrics, indicated similar patterns of variation, with squid from the Azores differing markedly from those on the continental shelf. No consistent pattern was apparent in meristic data. Partial Mantel tests indicated that similarity matrices for morphological data were significantly correlated with distance matrices for (a) geographic proximity, (b) whether the capture site was on the continental shelf or the Azorean bank, and (c) (beak data only) average seasurface temperature at site of capture. Partial Mantel tests on allozyme data for the same individuals support hypothesis (b). The results suggest that L. forbesi in the Azores may reasonably be regarded as a distinct stock, differing significantly from L. forbesi on the continental shelf.

Description: Abralia trigonura is a small squid that is an important member of the mesopelagic boundary community around Hawaii. Squids were aged by examining statolith growth increments, and various reproductive parameters were measured. Female longevity is ∼6 mo, and they become sexually mature at ∼3.5 mo. Male longevity is the same, but they become sexually mature at ∼2.5 mo. This species appears to be a multiple spawner, and peculiarities in the number of eggs found in the oviducts suggests that they spawn every few days. Possible advantages of this reproductive mode are examined.

Description: Fortyfour octopods from bottom trawls off Palmer Archipelago, south-eastern Argentina, south-eastern New Zealand, Crozet Islands and Showa Station were examined. Three species of Pareledone, three species of Graneledone and one species of Megaleledone were identified. All were characterized by having a single row of arm suckers. Mature males of P. harrissoni, P. adelieana and G. macrotyla were recorded for the first time. Hectocotylus and male reproductive organs of these species are described. On the basis of previously reported distributions and the present localities, P. charcoti, P. harrissoni and P. adelieana appear to have circumantarctic distributions. G. macrotyla was identified but the other two species of Graneledone could not be identified to species level because of the poor systematic state of this genus.

Description: Middle Valley is a hydrothermally active, sediment-covered rift at the northernmost end of the Juan de Fuca Ridge. Two hydrothermal centers are known from previous work: (1) a 60-m-high sediment mound with a 35-m-high inactive sulfide mound and two 20-m-high sulfide mounds 330 m to the south, one of which is known to be active, and (2) several mounds with attendant active hydrothermal chimneys. These sites (Sites 856 and 858, respectively), as well as other adjacent areas (Sites 857 and 855), were drilled during Leg 139 of the Ocean Drilling Program. Fluid inclusion petrographic observations and microthermometric measurements were made on a variety of samples and minerals recovered from these cores: (1) quartz from hydrothermally altered sediment; (2) low iron sphalerite and interstitial dolomite in massive sulfide; (3) calcite-sulfide veins cross-cutting sediment; (4) calcite and anhydrite concretions in sediment; (5) anhydrite veins cross-cutting sediment; and (6) wairakite and quartz veins cross-cutting mafic sills and sediment. Trapping temperatures of fluid inclusions in hydrothermal alteration minerals precipitated with massive sulfides range between 90° and 338°C. Fluid inclusions in calcite in carbonate concretions indicate these concretions formed between 112° and 192°C. Anhydrite in veins and concretions was precipitated between 137° and 311 °C. Quartz-wairakiteepidote veins in mafic sills and hydrothermally altered sediment were precipitated between 210° and 350°C. For all inclusions, there is a general increase in minimum trapping temperatures with increasing subsurface depth for all sites, with temperatures ranging from around 100°C at 2400 meters below sea level to around 275°C at 3100 mbsl. Eutectic and hydrohalite melting temperatures indicate that Ca, Na, and Cl are the dominant ionic species present in the inclusion fluids. Salinities for most inclusion fluids range between 2.5 and 7.0 equivalent weight percent NaCl. Most analyses are between 3 and 4.5 eq. wt% NaCl and similar to ambient bottom water, pore fluids, and vent fluid from Site 858. Trapped fluids are modified seawater, and there is no evidence for a significant magmatic fluid component. Oxygen isotopic compositions for fluids from which calcite concretions were precipitated, calculated from isotopic analyses of carbonates formed at low temperatures (133° to 158°C from fluid inclusions), are significantly enriched in 18O (δ1 8θ = +9.3‰ to +13.2‰), likely due to reaction with subsurface sediments at low water/rock ratios. Calcite that formed at higher temperatures (233°C) in hydrothermally altered sediment was precipitated from fluid only slightly enriched in 18O (δ1 8θ = +0.4%o). Estimated carbon isotope compositions of the fluid vary between δ13C = -7.0%e and -35.4‰ and are similar to the measured range for vent fluids.

Description: The statocyst and statolith of a mature female giant squid Architeuthis kirki Dell, 1970, caught in New Zealand waters are described. The organization of the chambers and internal projections of the statocyst can be interpreted as an analogue of a lamprey-like labyrinth with two semicircular canals. Size, sex, date of capture, and site of capture are reported for 24 A. kirki specimens caught in New Zealand waters from 1983 to 1988. A statolith from a specimen captured 3 May 1987 was sectioned and examined for microincrements, and the age assigned by assuming daily microincrementation. When size and date of capture are used to estimate annual growth rates, they yield rates similar to or slightly faster than those inferred from the statolith microincrements. Four different growth curves have been fitted to the length-at-age data: lowess (locally weighted least squares), exponential, logarithmic (power curve), and von Bertalanffy. Estimated von Bertalanffy curve parameters are k = 0.0036d-1, and L- infin = 2168 mm dorsal mantle length.

Description: Fahrtbericht der GEOMAR-Expeditionsteilnehmer. Fahrtroute (5.8. - 5.10.1993): Tromsoe - Murmansk - Svalbard - Franz-Josef-Land - Karasee - Laptevsee - Karasee - Barentsee - Murmansk - Bremerhaven

Description: Im Frühjahr 1967 hielt ich meine Antrittsvorlesung über die marine Aquakultur - die Fischzucht am und im Meer. Ich wollte damit eine neue Arbeitsrichtung in Kiel einläuten. Sie wurde in den folgenden Jahrzehnten zu einem wichtigen Feld der Fischereibiologie in Kiel. Thassilo Jaegers Lachsforellen, am Kieler Kraftwerk in Holger Graves Drehnetzkäfigen aufgezogen, und die Steinbutt-Küken aus Bülk sind Folgen dieseranschließend von Nellen und Rosenthal fortgeführten Arbeitsrichtung. (...)

Description: The home range system of the coelacanth Latimeria chalumnae was investigated along 11 km coastline at Grande Comore, Western Indian Ocean, between 1987 and 1991. 67 individuals were identified on individual white dot patterns. The home range consisted of daytime caves where fish aggregated in groups of up to 14 individuals while at night individuals moved singly downwards to a depth of 250 to 300 m in search of food. Site fidelity of at least 5 yr was found. The coelacanths used several caves within their home ranges. Cave size, cave occupation rate, average and maximum group size and cave preferences were studied. Tracking experiments with ultrasonic transmitters revealed horizontal home ranges of at least 8 km width. Population estimates of 200 to 230 individuals at Grande Comore confirm earlier counts. Large home ranges and highly mobility in a topographically narrow habitat apparently favoured inbreeding of the small local island population.

Description: Dissolved free amino acids (DFAA) and dissolved combined amino acids (DCAA) were determined in the porewater of sediment cores from the Norwegian-Greenland Sea (water depth from 1000 to 3300 m). Concentrations in the sediment column were generally found to decrease with depth. The amino acid composition of DFAA and DCAA was remarkably constant. The relative contributions of acidic amino acids decrease with depth, however. Composition patterns for samples for water depth 1000-2000 m and for deep-sea samples (water depth 〉 3000 m) show characteristic differences. Some secondary concentration maxima several centimeters below the sediment-water interface are found, probably related to the bioturbation activity of benthic macrofauna

Description: The forcing of abyssal recirculation gyres by cross-isopycnal mixing and wave fluxes near the deep western boundary is investigated. A three-layer isopycnal primitive equation model is applied in a series of experiments to an idealized basin with bottom topography. In the absence of deep western boundary current instabilities, cross-isopycnal mixing forces a cyclonic recirculation gyre, modified by topography, which is consistent with the traditional Stommel-Arons model. Instabilities of the boundary current fundamentally alter the mean basin-scale deep flow from a cyclonic recirculation to an anticyclonic recirculation. Bottom topography plays a key role in destabilizing the mean flow. The forcing mechanism for the interior recirculation is the horizontal divergence of momentum and potential vorticity fluxes carried by topographic waves that are forced by the boundary current instabilities. The strength of the recirculation gyre is linearly proportional to the kinetic energy of the waves, which is controlled in the present model by bottom drag, and well predicted by a simple scale analysis. This is essentially an adiabatic process. The addition of cross-isopycnal mixing forces the large-scale interior recirculation toward the pole, partially into boundary currents, through linear vorticity dynamics. Vorticity budgets reveal three dynamical regimes for the eddy-driven flows, the western boundary current, the recirculation region, and the interior. Similarities and differences between the mean flow and recent observations in the Brazil Basin are discussed.

Description: Fucus evanescens is recorded for the first time in Kiel Bight (western Baltic). It is now common at several sites in the lower zone of F. vesiculosus. Its arrival to the area and especially its increase in abundance seem to be recent. Epiphyte load in late spring was significantly higher on F. vesiculosus (20%) than on F. evanescens (5%). The immigration of F. evanescens from Danish waters may be connected to the decline in abundance of F. vesiculosus and F. serratus in the western Baltic.

Description: APIZym strips were used for measuring the activity of 19 enzymatic reactions in marine sediment samples from the continental slope of the Celtic Sea in 135…1630 m depth. The activities of phosphatases were dominant followed by esterases, peptidases, and glycosidases. The activities were influenced by the sediment depth within the cores and the depth of the station. The results indicate that the APIZym system is able to resolve vertical stratification and spatial variability of enzymes possessing activity rates exceeding 10 nmol substrate h−1 cm−3 in sediment but not of those with lower rates which for example would be found in deep‐sea sediments.

Description: Studies on the Mediterranean Undercurrent in the Gulf of Cádiz showed that bacterial abundance and biomass as well as heterotrophic activity were higher in the water of Mediterranean origin in 500–800 m depth than in the adjacent Atlantic water. Upwelling processes off Mauretania and Portugal were accompanied by high bacterial numbers (bacterial plate counts) in the mixed surface layer. Changes in the qualitative composition of the bacterial flora in the waters off West Africa and in the Arabian Gulf were explained by the introduction of dust from desert regions into the sea by aeolian transport. In the Western Baltic migration of fish was detected by the presence of special bacteria, which normally live on or in these animals. Regions with complex hydrographic structures such as the Western and Central Baltic Sea revealed interesting relationships between bacteriological abundance and activity on the one hand and characteristic physical and chemical properties, such as origin, salinity and O2/H2S‐content, on the other. The importance of bacteriological variables for the characterization of different water bodies is discussed.

Description: In the Deep Western Boundary Current (DWBC) mean velocities obtained by the F11/F12 dating method are far smaller (1–2 cm s−1) than direct velocity measurements (5–20 cm s−1). To resolve this discrepancy, a simple box model is presented that uses the ideas of Pickartet al. (1989, Physical Oceanography, 19, 940–951) to parametrize turbulent diffusion of the current with its surroundings. In contrast to previous models, however, the boundary conditions include all water masses forming the lower part of the DWBC (Denmark Strait Overflow Water, Iceland Scotland Overflow Water and Northeast Atlantic Water). The model-derived mean velocity of the DWBC leads to tracer concentrations that have to fit the observed F11 and F12 distributions, the F11/F12 ratios, and the tritium distributions. Moreover, the model area is extended from south of the Faroe bank along the continental margin of the American continent to 10°S. The model assumes uniform velocity and uniform turbulent mixing along the flow path of the DWBC, and enhanced turbulent mixing in the vicinity of the current compared to the ocean's interior allows the surrounding waters, which remain motionless, to accumulate tracers. The highest mean velocity of the DWBC, which results in model F12, F11, and 3H distributions as well as F11/F12 ratios, compatible to measurements of these tracers along the western boundary, are 4.8 cm s−1. Variations in the composition of the DWBC as well as changes in the time history of the source water masses do not increase the range of the model velocities.

Description: Eleven fish species from the Weddell Sea (Antarctic) were examined for infestation with anisakid nematodes. Two species of the genus Contracaecum and the sealworm Pseudoterranova decipiens were isolated from the liver and the body cavity of fish affected. Only two specimens of P. decipiens (1.4%) partly invaded the belly flaps. The following fish species were infested by P. decipiens at the given prevalences: Cygnodraco mawsoni (74.4%), Trematomus scotti (23.2%), Pagetopsis maculatus (10.0%), Cryodraco antarcticus (7.1%), Trematomus lepidorhinus (3.0%), and Dolloidraco longedorsalis (2.7%). All of these, except Trematomus scotti, are new host records. Chaenodraco wilsoni, Chionodraco myersi, Gerlachea australis, Racovitzia glacialis and T. eulepidotus were not infested. The reasons for low prevalence and intensity of infestation are seen in the difficulties of P. decipiens in completing its benthic life cycle in the Weddell Sea environment, in the absence of shallow coastal waters due to the floating shelf-ice. Cygnodraco mawsoni is a crucial intermediate host, without which completion of the parasite life cycle might not be possible. In order to clarify the taxonomical position of Antarctic Pseudoterranova, morphological comparisons with specimens of P. decipiens from the German and Norwegian coast were made using scanning electron microscopy. Results revealed no differences; hence, all specimens studied belong to the same species P. decipiens.

Description: The degradatlon of phytodetritus In the deep sea was studied in sediment samples of the NE Atlantic In spring and summer 1992 using I4C-labelled algal cells (Anacystis sp , Cyanophyceae) fed to the benthic population in ship-board experiments and measuring the liberation of labelled I4CO2 over time. The mineralization process showed a 2-step behaviour with an initial rapic rate whhich later slowed down, indicating the initial attack of easily degradable material of the complex food and the later utilization of less labile matter. The profile of degradation activity with sedimend depth showed no clear vertical gradient in March, but in August the activity in the top horizon increased by a factor of 6.1 to 7.8, which was coherent with increased bacterial numbers or biomass (factor of 1.3 to 1.7), respectively, and might be caused by the seasonal input of phytodetritus to the deep-sea bottom. The degradation measured was positively influenced by elevated incubation pressure mostly in summer, indicating that the summer stimulation of microbial activity in 1992 was based on the metabolic activation of the indigenous benthic community while surface-derived organisms attached to sedimented particles were of lesser importance whith respect to consumption of phytodetritus. Several aspects on quality of phytodetritus for nutrition of the deep-sea benthos, seasonality of detritus degradation, and influence of pressure on microbial activity are discussed

Description: The effect of midlatitude and tropical internal wave variability on current profile measurements is investigated and quantified to yield practical error estimates. First, a data set of Pegasus current profiles from the tropical Atlantic (6°S to 6°N) is analyzed for their rms down/up differences, which are compared with predictions from Garrett‐Munk type internal wave theory and with statistics derived from current meter moorings in the same region. The agreement in terms of amplitudes and vertical distribution proves that most of those differences are due to internal waves and not instrumental errors. Nonetheless, this is the noise of the measurements, if low‐frequency motions are sought, and the errors can thus be quantified using the same internal wave theories. At midlatitudes the error variance is the usual 44(N/3 cph) cm2/s2 with some latitude dependence, and the effect of averaging in the vertical or summing several profiles (e.g., up and down) is estimated. The same is done for equatorial situations, where construction of a crude equatorial frequency spectrum for internal waves yields 77(N/3 cph)cm2/s2 for the error variance. Again, error reduction due to averaging is estimated.

Description: Planktic foraminifers Neogloboquadrina pachyderma (sin.) from 87 eastern and central Arctic Ocean surface sediment samples were analyzed for stable oxygen and carbon isotope composition. Additional results from 52 stations were taken from the literature. The lateral distribution of δ18O (Full-size image (〈1 K)) values in the Arctic Ocean reveals a pattern of roughly parallel, W-E stretching zones in the Eurasian Basin, each ∼0.5‰ wide on the δ18O scale. The low horizontal and vertical temperature variability in the Arctic halocline waters (0–100 m) suggests only little influence of temperature on the oxygen isotope distribution of N. pachyderma (sin.). The zone of maximum δ18O values of up to 3.8‰ is situated in the southern Nansen Basin and relates to the tongue of saline (〉 33%.) Atlantic waters entering the Arctic Ocean through the Fram Strait. δ18O values decrease both to the Barents Shelf and to the North Pole, in accordance with the decreasing salinities of the halocline waters. In the Nansen Basin, a strong N-S δ18O gradient is in contrast with a relatively low salinity change and suggests contributions from different freshwater sources, i.e. salinity reduction from sea ice meltwater in the south and from light isotope waters (meteoric precipitation and river-runoff) in the northern part of the basin. North of the Gakkel Ridge, δ18O and salinity gradients are in good accordance and suggest less influence of sea ice melting processes. The δ13C (Full-size image (〈1 K)) values of N. pachyderma (sin.) from Arctic Ocean surface sediment samples are generally high (0.75–0.95‰). Lower values in the southern Eurasian Basin appear to be related to the intrusion of Atlantic waters. The high δ13C values are evidence for well ventilated surface waters. Because the perennial Arctic sea ice cover largely prevents atmosphere-ocean gas exchange, ventilation on the seasonally open shelves must be of major importance. Lack of δ13C gradients along the main routes of the ice drift from the Siberian shelves to the Fram Strait suggests that primary production (i.e. CO2 consumption) does probably not change the CO2 budget of the Arctic Ocean significantly.

Description: In this study a scenario is developed of two adjacent Mediterranean Water eddies (meddies) as they were observed merging and drifting through the Iberian Basin. Observations are based on four RAFOS floats (at 850–1050 dbar), two hydrographic surveys (centered roughly at 38°N, 24°W), and trajectories of surface drifters (drogued at 100 m). In April 1991, the meddy A was identified and labeled by surface drifters. During the revisit one month later two meddies were encountered, B1 and B2, in the vicinity of the former meddy A. The coalescence of B1 (subsequently identified as A, one month older) and B2 is inferred from a simple kinematic model describing the observed movement of the RAFOS floats for up to three months after the second CTD survey. The deduced vorticity front, radius ∼15 km, within B1 was of insufficient strength to keep the core waters of B1 isolated and prevent the absorption of B1 by B2. The resulting meddy (B1 + B2) showed a clear near-surface dynamical signal. Its deep root (1800 m) could explain the expulsion from the meddy of the remaining RAFOS float and surface drifter at the time of the meddy's collision with the Josephine Seamount. For the first time, a set of Lagrangian and hydrographic observations give direct evidence that neighboring meddies can merge as predicted by theoretical considerations.

Description: Two major meltwater events are documented in cores from the NW Labrador Sea. One occurred ca. 20,000 14C yr B.P. in association with deposition of a major detrital carbonate unit. Both prior to and after this event, δ18O values of near-surface planktonic foraminifera were 4.5%, indicating fully enriched glacial values. A younger event (ca. 14,000 14 C yr B.P.) is characterized by a dramatic change in δ18O from 4.5 to 2.0% and coincided with the retreat of ice from the outer SE Baffin Shelf, possibly into Hudson Strait. These meltwater events coincide with Heinrich (H) layers 1 and 2 from North Atlantic sediments. The 14,000 14C yr B.P. meltwater event indicates that the eastern margin of the Laurentide Ice Sheet also underwent rapid retreat at approximately the same time as other ice sheet margins around the NE North Atlantic. A third major detrital carbonate event at the base of HU87-033-009, possibly correlative with Heinrich layer 3, occurred ca. 33,960 ± 675 14 C yr B.P.; however, this is older than the accepted date for H-3 of 27,000 14C yr B.P. and may be H-4.

Description: Vesteris Seamount is a solitary alkaline volcano in the Greenland Basin some 280 km NW of Jan Mayen. Topographic and geophysical studies have shown no sign of an associated plume trace. Evidence from ash layers in sediment cores around the volcano and dating of dredged samples show that it has been active in Quaternary times. The lavas from Vesteris studied here consist of basanites, tephrites, mugearite, and alkali basalts. Crystal fractionation models are consistent with the generation of the tephrites and mugearite from a basanitic parent. Extensive kaersutite fractionation is required late in the fractionation sequence to produce the extreme mugearite composition. Na-Al-Fe-rich green cores to many clinopyroxene phenocrysts at Vesteris suggest a fractionation history beginning at high pressure in the mantle. Differences between Vesteris and Jan Mayen in the ratios of highly incompatible trace elements such as Ce/Pb and Rb/Cs, which will not normally be fractionated from one another during mantle melting, suggest that the two are not derived from the same source. Relatively unradiogenic Sr isotope ratios (compared with Bulk Earth), and highly incompatible trace element patterns similar to those for St. Helena, suggest that Vesteris magmas are derived from a depleted, asthenospheric source. We propose that the Vesteris basanites are very low degree partial melts (˜1%) of this source, most probably those which give rise to the seismic low-velocity zone (LVZ). Such small-degree melts may preferentially tap small-scale heterogeneities in the asthenosphere. Vesteris lies at the intersection of two major structural trends in the Greenland Basin—(1) a zone of major reorientation of spreading direction on the Mohns Ridge north of Jan Mayen and (2) the extension of the Kolbeinsey Ridge axis. We propose that a combination of the extensional stress fields related to these two lineaments produces sufficient dilation of the lithosphere at Vesteris to allow magmas from the LVZ to reach the surface.