ALBERT

Description: The Cretaceous Western Interior seaway provided a wide, relatively shallow connection between the polar ocean and the subtropical ocean, both of which invaded the comparatively shallow western Interior Seaway and left distinctive faunal and floral records. Water masses from these very different climatic regions may have had similar densities but very different salinities and temperatures. Mixing of such disparate water masses could have produced a third water mass with a density greater than one or both of them, and this mechanism may have caused the Western Interior Seaway to become a significant source of intermediate water to the world ocean. The abrupt change in environmental conditions at the oceanic front where mixing occurred would probably have killed the plankton and introduced large amounts of organic matter into the descending, third water mass, leading to the development of an intense oxygen minimum. -from Authors

Description: Im Auftrag des Instituts für Meereskunde an der Universität Kiel und dem Institut für Energieanwendung und Rationelle Energiewirtschaft an der Universität Stuttgart; Die vorliegende Arbeit ist das Ergebnis einer 3-monatigen Studie über Einträge und Wirkungen von Kohlenwasserstoffen, die durch Aktivitäten der offshore Erdölproduktion und durch die Tankschiffahrt in die marine Umwelt gelangen. Sie umfaßt zunächst einen Überblick über Art und Umfang von Einträgen aus weltweiten und regionalen offshore Aktivitäten. Als exemplarische Fallstudie werden ergänzend aktuelle Informationen über Art und Umfang von Entsorgungen in die Nordsee durch die norwegische Ölplattform OSEBERG C gegeben. Globale und regionale Eintragsgrößen aus dem Transport von Rohöl und seiner Raffinate durch Tanker werden anschließend erörtert. Zum erständnis der Auswirkungen auf die Lebewelt erschien eine Betrachtung der Ausbreitung von Öl im Meer sowie dessen Veränderung unter dem Einfluß physikalisch-biologischer Abbauprozesse als notwendig. Abschließend werden potentielle Auswirkungen eines küstennahen Ölunfalls auf den betroffenen Wirtschaftsraum diskutiert und auf Probleme hingewiesen, die sich aus der Entsorgung ausgedienter Ölförderplattformen ergeben können.

Description: The present study contributes new information on the cephalopods off Namibia, contains the first record of Ornithoteuthis volatilis (Sasaki, 1915) in the Atlantic, and adds records of six species in the Benguela Current and three species in Namibian waters. The presence of certain species seldom encountered in the Benguela Current has been confirmed. A compilation of the cephalopod fauna off Namibia had also been included, listing 65 species. Additional morphological data on Stoloteuthis leucoptera, Lycoteuthis lorigera, Architeuthis sp., Pholidoteuthis boschmai, Ornithoteuthis volatilis, Eledone nigra, and Graneledone sp. have been provided. The status of the genus Lycoteuthis has been reviewed in the light of the first collection of Lycoteuthis lorigera (Steenstrup, 1875) males in the Atlantic, and Lycoteuthis diadema (Chun, 1900) has been considered to be a synonym for Lycoteuthis lorigera

Description: An investigation was carried out on larvae of the oceanic tropical squid Sthenoteuthis pteropus in the equatorial Atlantic (2°30′N–7°S;12°W –8°30′E) The age of the larvae was calculated from the statolith microstructure of 20 larvae; mortality was estimated from the size structure of 1128 larvae. The larval stage lasts 32–38 days. At ages ranging from 14 to 38 days. the daily relative growth rates of mantle length decrease from 7.5 to 2.8% day −1 and from 14–16 to 5.8% of body weight day −1 At age 12–24 days, mortality rates were estimated using both raw catch data and corrected data accounting for net avoidance. The mean value of raw mortality rates was 0.189, the corrected value was 0.158. During the proboscis division (transformation of the larva into juvenile) at age 25–35 days, a sharp decrease in larval growth rates and a simultaneous increase in mortality rates (raw 0.443, corrected 0.379) were observed.

Description: The concentrations of intermediate and end products of anaerobic energy metabolism and of free amino acids were determined in mantle musculature and blood sampled from cannulated, unrestrained squid (Loligo pealei, Illex illecebrosus) under control conditions, after fatigue from increasing levels of exercise, and during postexercise recovery. Phosphagen depletion, accumulation of octopine (more so in Illex than in Loligo), and accumulation of succinate indicate that anaerobic metabolism contributes to energy production before fatigue. Proline was a substrate of metabolism in Loligo, as indicated by its depletion in the mantle. In both species, there was no evidence of catabolism of ATP beyond AMP. A comparison of the changes in the free and total levels of adenylates and the phosphagen indicates an earlier detrimental effect of fatigue on the energy status in Loligo. The acidosis provoked by octopine formation in Illex was demonstrated to promote the use of the phosphagen and to protect the free energy change of ATP such that the anaerobic scope of metabolism during swimming is extended and expressed more in Illex than in Loligo. In both species, there was no decrease in the sum of phospho-L-arginine, octopine, and L-arginine, and thus no release of octopine from the mantle, thereby supporting our earlier claim that octopine and associated protons are recycled in the mantle tissue. Overall, the metabolic strategy of Loligo is much less disturbing for the acid-base status. This strategy and the alternative strategy of Illex to keep acidifying protons in the tissue may be important for the protection of hemocyanin function in the two species.

Description: Horizontal starch gel electrophoresis was used to investigate levels of genetic differentiation between four samples of the nominate squid species Martialia hyadesi Rochbrune and Mabille, 1889, obtained from regions of the Patagonian Shelf and Antarctic Polar Fron-tal Zone over 1000 km apart. M. hyadesi is an ecologically important South Atlantic ommastrephid squid and it is probable that, in the future, fishing effort will be increasingly directed towards this species. Details regarding the population structure of the species are therefore required. In comparison with the other three samples of M. hyadesi, one of the samples from the Patagonian Shelf (PAT 89II) exhibited fixed allelic differences at 16 of the 39 enzyme loci which were resolved (genetic identity, I=0.51). This high level of genetic differentiation contradicts the apparent morphological similarity between samples, indicating the presence of a cryptic or sibling congeneric species. Deviations from Hardy-Weinberg equilibrium and significant differences in allele distribution were also detected within and between the other three putative M. hyadesi samples, suggesting that the species fails to maintain effective panmixia across its geographical range. The occurrence of both temporal (1986 cf. 1989) and geographic structuring within the species complex is consequently indicated, caused possibly by an overlap of reproductively isolated stocks (stock mixing) outside their respective breeding areas. Low levels of genetic variability were detected throughout the samples examined, estimates of average heterozygosity per locus within the two species detected being in the order of 0.01 and 0.002. These values are discussed in relation to levels of genetic variability reported for other squid species, and in comparison with values typically expected for marine invertebrates.

Description: Variations in the distribution and abundance of coastal cephalopods in the Cabo Frio (Brazil) region were studied from 71 trawl samples obtained between November 1986 and October 1988. Species abundance was compared over the depths sampled and their relationship with hydrological features investigated. Best catches were markedly associated with upwelling of nutrient-rich water (South Atlantic Central Water) during the spring-summer period, at depths from 45 to 60 m. Two species, Loligo sanpaulensis and Eledone massyae, account for most of this increase. Variations in abundance of these species are related to recruitment and periods of high productivity on the feeding grounds. Benthic octopods such as Octopus tehuelchus, O. vulgaris and Eledone gaucha occurred in small numbers at 60 m. Species broadly distributed in the western Atlantic, such as Semirossia tenera and Loligo plei, were also present.

Description: Species that reach the end of a life-history stage (transform) at relatively fixed sizes may often grow nonasymptotically before transforming. Many species of squid and at least some larval frogs, fish, and insects appear to follow this pattern. When data on body size at a range of ages are available for such taxa, they are often described well by exponential curves or by power curves that are concave upward. When such data are transformed to mean sizes for ages or age classes, they are likely to fit asymptotic growth models such as the logistic and Gompertz curves. These curves are good descriptions of the behavior of the population mean but poor descriptions of the pattern followed by any individual in the population. Analyzing and presenting data on size at age using mean sizes can thus lead to incorrect interpretations of growth patterns and should be avoided.

Description: There are three major breeding populations of southern elephant seals centered on Macquarie Island, Kerguelen-Heard Islands and South Georgia-Antarctic Peninsula. The composition of the diet differs between these populations based on published data from Signy Island and data presented here from Macquarie and Heard Islands. These differences in diet appear to be linked to the location at which seals were sampled ranging from the least Antarctic (Macquarie Island) to the most Antarctic (Signy Island). The major food remains consisted of cephalopod beaks and fish eye lenses. More benthic material was found at Heard Island than at Macquarie Island. The diet at Macquarie Island differed between summer and winter and between young animals and adults. The difficulty in collecting dietary samples of southern elephant seals near their main foraging areas makes the study of the feeding ecology of this species extremely difficult in comparison with other Southern Ocean species.

Description: The stomachsof 23 striped dolphins (Stenella coeruleoalba Meyen, 1833, Cetacea), stranded along the Ligurian coast (western Mediterranean Sea), contained 32 species of cephalopods, crustaceans and fishes, totalling an estimated 2,723 prey specimens representing about 36 kg in weight. Cephalopods and bony fishes were equally important in the diet (50%). Todarodes sagittatus (34.5%) and Micromesistius poutassou (25.9%) were found to be the most important food species. Other species belonging to six cephalopod families, three crustacean families and nine bony fish families, contributed to the diet with variable numbers, weights, and occurrences, demonstrating the opportunistic character of striped dolphin feeding.

Description: Using metabolic (in vivo) labeling methods and immunoblotting (Western) analysis, we determined the threshold induction temperature for enhanced synthesis of heat-shock proteins (HSP70 and HSP90) and the constitutive levels of these two classes of HSPs, respectively, in brain, gill, and liver of four species of marine teleost fishes acclimatized to a common temperature (10°C). For a given tissue of a species and among tissues of a species, little variation was found in HSP induction temperatures. However, among tissues of a species, the constitutive levels of HSPs differed substantially. Among species, wide variation was found in induction temperature (up to 8°C when averaged for all tissues) and HSP concentration (greater than 10-fobld differences for a single tissue). These results, obtained by analysis of animals from natural populations, contradict many of the assumptions, based largely on in vitro studies of isolated cells and tissues, about the dependence of the HSP threshold induction temperature and HSP concentrations on the previous acclimatization temperature. The wide variation in the HSP threshold induction temperatures among the different species and the wide variation in constitutive HSP levels among and within species may reflect, in addition to recent thermal exposure, the thermal history of the species during its evolution and the occurrence in the individual's habitat of other stressors that, like temperature, are capable of activating the heat-shock (stress) response.

Description: In the first half of the 20th century small founder groups of the Amur sleeper, Perccottus glenii, have been transferred from their native range in the Far East to some regions of the European part of Russia. In order to investigate the consequences of the introductions, 15 Far East populations and 11 European populations, that originated from two transfers, were studied for their variability on two enzyme loci (Sod and Odh) using polyacrylamide gel electrophoresis. For both loci, divergence between populations and heterozygosity in the populations were higher in the colonized regions than in the native range. Heterozygote advantage in small founder populations seems to be a factor resisting genetic drift and determining the changes observed in the genetic structure of the introduced populations.

Description: Die Terra Nova Expedition (1910-1913) von Robert Falcon Scott wird bis heute überschattet von dem tragischen Ende des Vorstoßes zum Südpol, den Scott mit seinen vier Begleitern im Januar 1912 - einen Monat nach Amundsen - erreichte. Dabei gerat leicht in den Hintergrund, daß neben dem Vorstoß zum Pol umfangreiche wissenschaftliche Untersuchungen einen wichtigen Schwerpunkt der Expedition bildeten. So wurden zahlreiche meteorologische, geologische und biologische Untersuchungen und Erkundungen von mehreren, unabhängig voneinander operierenden, wissenschaftlichen Feldgruppen durchgeführt. Eine dieser Feldgruppen war die Western Geological Party', die im Sommer 1911/12 unter der Leitung des Geologen Griffith Taylor von Granite Harbour ausgebend, einem tiefen natürlichen Hafen auf 77°S, die Küste von Süd Victoria Land erkundete. Die Forschungsergebnisse mit Hinweisen auf eine außergewöhnlich reiche Vegetation wurden im Reisebericht der Terra Nova Expedition bereits 1913 veröffentlicht (TAYLOR 1913). Aufgrund seiner abgeschiedenen Lage ist dieses Gebiet seitdem jedoch nur sehr selten besucht worden und in Vergessenheit geraten, ast 1989 wurde die außergewöhnlich reiche Vegetation wiederentdeckt.

Description: During the years 1989–1993 an intensive collection of fishes from the aphotic zone (below 150 m) of the northern part of the Gulf of Aqaba was conducted. This survey recorded 69 fish species, 8 elasmobranchs, and 61 teleosts, belonging to 45 families. Fifteen species are endemic to the Red Sea: Mustelus mosis, Narcine bentuviai, Rhinobatos punctifer, Ophichthus echeloides, Rhynchoconger sp., Physiculus marisrubri, Ostichthys hypsipterygion sufensis, Pterygotrigla sp., Uranoscopus marisrubri, Parascolopsis sp.1 and sp. 2, Atrobucca geniae, Chromis pelloura, Samariscus sp., Thamnaconus modestoides erythraeensis. Eleven species are new records for the Red Sea: Gymnothorax johnsoni, Rhynchoconger sp., Synodus doaki, Pterygotrigla sp., Chelidoperca pleurospilus, Carangoides equula, Parascolopsis sp. 1 and sp. 2, Bodianus leucostictus, Paracaesio sordidus, and Samariscus sp. Two species, Cociella crocodilo and Parascolopsis eriomma, are first substantiated records for the Red Sea. None of the species recorded in this list is considered conventional deep-sea fishes. The ichthyofauna of the aphotic zone of the Gulf of Aqaba is composed of species of shallower origin.

Description: Digitised outlines of a serially sectioned K-feldspar grain from a Cordilleran granitoid have been analysed for their fractal dimension. Although the grain boundary outlines are not truly fractal in the sense of Mandlebrot (1982), they do show a self-similarity over a statistically definable range, and can thus be assigned a dimensional value between 1 and 2. Each grain section has fractal dimension (D) 〉 1, ranging from 1.21-1.30. Scatter within the data sets have been used to define separate (pseudo)fractal elements that further characterise each grain outline. The development of fractal geometries within a particular granitoid can be broadly related to crystallisation within Ab-An-Or-Qz space. For example, Cordilleran T-type granitoids that crystallise from An-rich liquids may be expected to show both Euclidean and fractal geometries, while minimum melts and 'S'-type granites that crystallise in broadly eutectic proportions will have textures dominated by (pseudo)fractal grain outlines. The non-integer values that describe grain shape may also be useful in estimating the total grain (porosity) volume within the rock.

Description: Current measurements from two consecutive yearlong deployments of three moored stations at the western end of the equator in the Atlantic, along 44°W, are used to determine the northwestward flow of warm water in the upper several 100 m and of the southeastward counterflow of North Atlantic Deep Water (NADW). Measurements from three acoustic Doppler current profilers (ADCPs) looking upward from 300 m toward the surface allowed calculation of a time series of upper layer transports over 1 year. Mean transport through the array for the upper 300 m is 23.8 Sv with an annual cycle of only ±3 Sv that has its maximum in June-August and minimum in northern spring. Estimated additional mean northwestward transport in the range 300–600 m is 6.7 Sv, based on moored data and shipboard Pegasus and lowered ADCP profiling. In the depth range 1400–3100 m a current core with maximum annual mean southeastward speed of 30 cm s−1 is found along the continental slope that carries an estimated upper NADW transport of 14.2–17.3 Sv, depending on the extrapolation used between the mooring in the core and the continental slope. This transport is higher than off-equatorial estimates and suggests near-equatorial recirculation at the upper NADW level, in agreement with northwestward mean flow found about 140 km offshore. Below 3100 m and above the 1.8°C isotherm, only a small core of lower NADW flow with speeds of 10–15 cm s−1 is found over the flat part of the basin near 1.5°N, clearly separated from the continental slope by a zone of near-zero mean speeds. Estimated transport of that small current core is about 4.5 Sv, which is significantly below other estimates of near-equatorial transport of lower NADW and suggests that a major fraction of lower NADW may cross the 44°W meridian north of the Ceara Rise. Intraseasonal variability is large, although smaller than observed at 8°N near the western boundary. It occurs at a period of about 1 month when it is dominant in the near-surface records and corresponds to earlier observations in the equatorial zones of all oceans and at a period of about 2 months when it is dominant at the NADW level and could be imported either from the north along the boundary or from the east along the equator. The existence of an annual cycle in the deep currents of a few centimeters per second amplitude, as suggested by high-resolution numerical model results, could neither be proven nor disproven because of the high amount of shorter-period variability.

Description: Lower and upper survival temperatures of microthalli of 25 species of South American Phaeophyceae isolated from central Peru (14°S) to the Canal Beagle (55°S) were determined using 2-wk exposure for the upper and 4-wk exposure for the lower limit. All species survive 4 wks at -2°C. With respect to the upper limit, species reported only from southernmost South America tolerate 19.9 to 24.5°C (n=8), and species occurring from Cape Horn to central Chile 24.6 to 27.4°C (n=7). Three species that occurred as far north as northern Chile and Peru before the 1982–1983 El Niño event, and whose northern limit was dramatically shifted southwards in 1983, tolerate 20.8 to 25.3°C, whereas five species that have survived in Peru tolerate 25.6 to 28.5°C. Tinocladia falklandica which tolerates 27.8 to 28.1°C but lives only in southernmost South America and Striaria attenuata, which tolerates 31.6 to 31.9°C but occurs at ca. 42°S, are exceptional. Their high temperature tolerance may have no adaptive value in South America. They are restricted to the cold-temperate region due to low temperature requirements for reproduction or for reasons yet unknown. In general, the northern distributional limits of the Phaeophyceae studied along the temperate Pacific coast of South America are reproduction boundaries, except in El Niño years when they are redefined according to the species' upper suvival limits. Temperature tolerance of isolates from northern Chile and Peru agrees well with maximum temperatures reached during the 1983 El Niño.

Description: During a cruise in the Baltic Sea in March/April 1991, dissolved lipids were concentrated from acidified sea water by adsorption on reversed phase material; the free fatty acids in the lipids were isolated. Titration of the acids with 0.01 mol/l methanolic KOH resulted in a very poor titration curve; assessing total concentration of organic acids in sea water by base titration appears to be impractical. After derivatization with p-phenylphenacyl bromide under crown ether catalysis the fatty acids were analyzed by micro-bore HPLC with UV-detection and comparison with standard reference substances. Some unknown fatty acids were characterized by GC/MS. Total concentrations were in the range from 1 to 4.5 nmol/l. They were the same in parallel samples liquid/liquid extracted with dichloromethane. The HPLC spectra of the fatty acids in both kinds of samples were also quite similar. This confirms earlier observations that adsorptive concentration of dissolved fatty acids and non-polar lipids from sea water is as effective as liquid/liquid extraction. Higher amounts of fatty acids can be concentrated by adsorption from large water volumes, thus lowering detection limits. Palmitic acid had by far the highest concentration in every sample followed by myristic acid, lauric acid, and stearic acid. Palmitoleic acid and oleic acid were the most abundant unsaturated acids. The other saturated and unsaturated acids had medium to low concentrations.

Description: Skin and hair samples of harbour seals (Phoca vitulina) found dead along the west coast of northern Germany in 1988 were analysed for total mercury, cadmium and lead. Cadmium and lead concentrations were below the detection limit in most skin samples. The mercury content of the hair (median: 23.1 μg g−1 wet wt) was several magnitudes higher than the mercury content of the skin (0.27 μg g−1 wet wt). Mercury concentrations in hair samples were significantly higher than lead concentrations (0.54 μg g−1 wet wt), which significantly exceeded cadmium levels (0.09 μg g−1 wet wt). Female seals revealed lower cadmium concentrations in the hair than male seals. Accumulations of metals with age were observed for cadmium and lead in hair samples and for mercury in skin samples of male seals. A connection between metal accumulation and pigmentation or rather moult was clearly recognizable.

Description: Tube‐dwelling has been recognized previously as a life‐style for several meiobenthic species, but behavioural observation of living specimens has rarely been reported. The extent to which tube‐building and tube‐dwelling occurs within meiofauna, and how they have influenced evolutionary and ecological processes as well as morphology within these organisms, is relatively unknown but potentially of great significance. In addition to direct observation of tube‐building and the occurence of tubes in natural habitats, the internal anatomy associated with tube‐building in two nematode species (Ptycholaimellus jacobi, P. ponticus) and one harpacticoid copepod species (Stenhelia palustris) is the focus of this study. Special attention is given to the secretory products, glands, and their association with secretory pores. Also, the role of meiobenthic tube‐dwelling activities in relationship to their environment is extensive discussed.

Description: The spreading of Mediterranean Water (MW) released through the Straits of Gibraltar is studied with hydrographic data, oxygen, nutrients and for the first time with chlorofluoromethane (CFM, compounds F11 and F12) distributions along seven sections in the Gulf of Cadiz, and with measurements in the Western Alboran Sea and west of the Gulf. The properties of MW entering the Gulf are deduced from CFM-salinity correlations east and west of the Straits as well as from property-depth profiles in the Western Alboran Sea. At the time of the survey, the outflow originated from depths above the salinity maximum of the Intermediate Water in the Alboran Sea. It turned out that the F11/F12 ratio of the outflow is equal to the ratios found in the Atlantic water in the Gulf of Cadiz; thus the ratio carries no time information in the region. A model is developed to describe mixing of the MW undercurrent with overlying North Atlantic Central Water (NACW) from different depths. The contribution of each layer to the mixing is parameterized by a weighting factor, which has to satisfy the balances of potential temperature (θ), CFMs, oxygen and nutrients in the MW undercurrent. It is shown that entrainment of water from shallower depths into the undercurrent is important near the Iberian Continental Shelf. Farther west and south, the undercurrent mainly mixes with water from near the salinity minimum of the NACW. For regions where the undercurrent has left the bottom, additional mixing with North Atlantic Deep Water (NADW) has to be taken into account. The percentage of MW in the undercurrent decreases from 76% hear the Straits to about 34% at 7°30′W for the lower core (MI) and about 22–24% for the upper core (Mu). Assuming an outflow of undiluted MW through the Straits of 1.0 Sv, the transport of the undercurrent can be calculated by determining an average dilution factor for each section. The undercurrent transports 2.0 Sv just west of the Straits and 3.6 Sv leave the Gulf of Cadiz. At 36°N, 9°54′W, a meddy with unusually high temperatures and salinities below 500 m was found, covering the density range for both cores, Mu and Ml. From the θ−S characteristics and the evaluated mixing scheme of the meddy it appears to have formed near 7°W in the Gulf, a region up to now not proposed in the literature, and moved westward without much further mixing.

Description: In April 1990, 488 marine fish belonging to 30 species from central Phillipine waters were examined for flesh parasitic infections that may affect their consumability. One species of hemirhamphids and 3 species of belonids harboured plerocercoids of Otobothrium penetrans Linton, 1907 (Proceedings of the U.S. National Museum33, 85–126). This is the first record of this parasite from Pacific fish species. The highest intensity of infection found was 8 in Tylosurus crocodilus. Most of the larvae were located between the dorsal spines of the vertebral column, only 32% were found in the fillets. Based on the present material we give a description of the plerocercoid stage of the species using scanning electron microscopy of the armature and morphometrical measurements. Comparison to results from earlier findings of O. penetrons by Linton (1907; 1924, Proceedings of the U.S. National Museum64, 1–114) and to O. kurisi by Shields (1985, International Journal for Parasitology15: 635–643) lead to the conclusion that the latter species is a synonym for O. penetrans.

Description: New light is shed on Worthington's concept of the North Atlantic circulation, postulating the existence of two anticyclonic gyres. This concept, which seems to have been laid to rest in the last decade, has now been reinforced by the results of a simple linear Sverdrup circulation model yielding a band of westward transport all across the North Atlantic at about the Azores latitude. This narrow band is called the Azores Countercurrent (AzCC) and matches the position of westward flow required by Worthington's “northern gyre.” An anomaly in the meridional change of the wind-stress curl in the eastern North Atlantic has been identified as the driving mechanism. A comparison with observations shows that the AzCC is verified in many analyses of historical datasets and synoptic surveys. A lack of the AzCC in other analyses is probably due to missing meridional sections, strong smoothing, and the superimposed Ekman flow close to the sea surface directed to the southeast. The AzCC has not been verified in low-resolution general circulation models applying simplified wind-stress fields and large friction coefficients, but there is evidence for its existence in recent high-resolution models driven by realistic wind stresses. Based on these findings, a new pattern for the wind-driven upper ocean circulation of the midlatitude North Atlantic is presented.

Description: Middle Valley is a sediment-covered rift near the northern end of Juan de Fuca Ridge. Hydrothermal fluids are presently being discharged at two vent fields about 3 km apart, Bent Hill and the area of active venting. The hydrothermally active chimneys at both Bent Hill and the area of active venting consist of anhydrite and Mg-rich silicates with minor pyrite, Cu-Fe sulfide, sphalerite, and galena. Hydrothermal discharge in these areas appears to be focused along extensional faults. At the Bent Hill massive sulfide deposit, clastic sulfide layers are interbedded with hydrothermally altered and unaltered hemipelagic and turbiditic sediment along the flanks of the sulfide mound. Sulfide textures and mineralogy suggest that the Bent Hill sulfide mound formed by the build-up and collapse of sulfide chimneys, the resedimentation of sulfide debris and the formation of clastic sulfide layers, and the infilling and replacement of clastic sulfides by hydrothermal fluids near vents. Sulfur isotope values that are consistently more positive than basaltic sulfur support the addition of seawater sulfur. Pb isotope values for the Bent Hill deposit that are transitional between midocean ridge basalt (MORB) and Middle Valley sediments indicate that the sulfides probably formed from fluids which originated in the oceanic crust but which have been modified by reaction with lower temperature (〈273°C)fluids generated in the sedimentary pile, similar to those now venting in Middle Valley.

Description: Nine large box cores collected in the western Greenland-Iceland-Norwegian (GIN) Sea were analyzed for calcium carbonate content and coarse fraction components. Stratigraphic control is based on oxygen isotope records performed on four of the cores. All cores were correlated using oxygen and carbon isotope data, fluctuations in calcium carbonate content, coarse terrigenous particle content and volcanic ash beds. Glacial and interglacial cycles are documented by a number of terrigenous particle events and differentiated calcium carbonate production which can be correlated to major paleoceanographic and paleoclimatic shifts. In the older core sections, extensive deposition of ice-rafted detritus (IRD) persisted until about oxygen isotope stage 9 and document a relatively stable environment in this area, strongly influenced by cold surface water masses. The following interval was characterized by variations in the general surface water circulation pattern, although high amounts of IRD are still present in Iceland Sea sediments. Pronounced shifts in terrigenous input and pelagic carbonate records were identified close to the oxygen isotope stage Full-size image (〈1 K) and Full-size image (〈1 K) boundaries, indicating massive melting of icebergs in the western GIN Sea. These enormous inputs of debris were followed by an increase in calcium carbonate production caused by maximum intrusion of warm Atlantic surface waters. Relatively high calcium carbonate contents also show that only little dilution by fine-grained material and a minimum of ice melting occurred during these warm phases. During oxygen isotope stage 5, conditions were more uniform indicating a less pronounced westward penetration of Atlantic waters as compared to the Holocene. The last glacial (stages 4-2) is characterized by the occurrence of “Heinrich”-like events, although high IRD contents were present throughout this interval. A distinct contrast between the northernmost cores and the cores in the south is indicative of a rather strong westward penetration of Atlantic water in the north and of an area dominated by cold water east of the Kolbeinsey Ridge during the Holocene. However, conditions west of Jan Mayen seem to have remained constantly dominated by cold surface waters throughout the whole time investigated.

Description: Late Pleistocene climatic and paleoceanographic changes in the Norwegian-Greenland Sea are reflected in eleven long sediment cores by variations in calcium carbonate content and calcareous biogenic components versus coarse terrigenous ice-rafted detritus (IRD). High contents of IRD in glacial sequences are evidence for an enhanced melting of sea ice and icebergs. In contrast, high calcium carbonate contents indicate the inflow of warm Atlantic surface waters. The petrographic IRD composition in cores from the eastern and central Norwegian-Greenland Sea shows that the terrigenous material was predominantly derived from Scandinavia. Thus, it can be concluded that changes in the terrigenous input were caused by oscillations of the Late Pleistocene Scandinavian ice sheet. Changes in the extension of this ice sheet during the last 130 ky correlate well with our IRD data.

Description: Mass-balanced paleogeographic reconstruction can be extended into reconstruction of the paleogeology, using information inherent in the mass/age distribution of the sediments. The reconstruction method removes sediments from their site of deposition and replaces them as overburden onto the sites from which they were eroded. The mass/age and spatial distribution of the sediments contain the information required to determine the age and lithology of the rocks that made up the overburden. Replacing the overburden onto the source areas in terms of age and lithology defines the geologic history of a region in much greater detail than previously thought possible.

Description: Undrained monotonie compression tests were conducted on loose sand samples subjected to an initial isotropic stress state, and undrained cyclic compression tests with no shear stress reversal were performed on loose sand samples subjected to initial anisotropic stress, in order to establish the stress conditions needed for triggering contractive flow deformation and the corresponding steady-state characteristics. It was shown that the peak strength envelope was also the triggering strength envelope, which appears to be unique for samples prepared by the moist tamping method and independent of stress path. It was established that the failure envelope for a given sand is unique but that the steady-state strength was not unique and was dependent on void ratio and stress conditions at the onset of flow failure. The use of normalized stress space is very helpful in the analysis of undrained monotonie and cyclic compression tests and permits ready prediction of strain-softening and strain-hardening behaviour. An analysis of data on various sands has shown that the stress conditions at the time of triggering contractive flow deformation and those at steady state can be related to the slope of the steady-state lines.

Description: Part 1: Synopsis Part 2: Publications

Description: Samples of two loliginid squids Alloteuthis africana and A. subulata were collected from the continental shelf off the west Sahara in August-September 1987. Statoliths were taken from 124 specimens and processed using statolith ageing techniques. Statoliths of both species were very similar in shape. In the ground statolith, growth increments were examined and grouped into four growth zones distinguished mainly by the width of the increments. Age of adult mature males of both species did not exceed eight months, that of females six months. Alloteuthis africana grew faster than A. subulata in weight and, particularly, in length. At age 180 d the mantle of A. africana was twice as long and the body weight 1·2–1·5 times as large. Both species matured over a wide range of sizes and ages (from 120 to 180 d). The life span of A. africana and A. subulata hatching between January and May on the west Saharan shelf is about six months, much shorter than that of A. subulata in its northern temperate range.

Description: This paper is concerned with the finding of an immature female of the species Ancisrr01eurhis lichtensteini off the Galician coast (NW Spain). This is the first record of the species in European Atlantic waters, and extends its northern latitudinal distribution in the Atlantic Ocean. The geographical distribution of the specics is discussed.

Description: Stomach contents from 17 sperm whales, 15 males and two females, caught during commercial activities in 1981-1984 in the Azores region were identified and measured. A total of 28 738 cephalopods and 16 fish were represented in the collections. In addition, there were tunicates in two whales and man-made products in three whales. None of the stomachs were empty. Flesh was present in 94.1% and indigestible fragments alone, including mandibles (beaks) of cephalopods, were present in 5.9% of the stomachs. Twelve species of cephalopod were represented by flesh and 40 species were represented by lower beaks. The cephalopod families contributing food to the whales in this region are, in order of their contribution by estimated mass, the Octopoteuthidae (39.8%), the Histioteuthidae (32.7%), the Architeuthidae (12.1%), the Lepidoteuthidae (4.5%), the Ommastrephidae (3.4%), the Pholidoteuthidae (2.1%), the Cycloteuthidae (1.9%), the Cranchiidae (1.7%) and eight other families each contributing less than 1% by mass. Presence of Gonatus beaks in the stomachs show which whales have migrated southwards to the Azores just prior to capture and the presence of a large Megalocranchia species possibly shows which whales have migrated from higher latitudes off Iceland. However, the presence of Teuthowenia maculata shows which whales came north from the West coast of Africa, just prior to capture. The modal mass of cephalopods consumed is 400-450 g which represents 0.00001 of the whales' body mass. 77.5% of the species eaten have luminous organs and 82% of the species are neutrally buoyant. It seems likely that the sperm whale is obtaining 77% of its food by swimming through luminous shoals of slow-swimming, neutrally bouyant squids and only about 23% by chasing faster swimming, larger cephalopods. Cephalopods not previously recorded from the North Atlantic are Onychoteuthis borealijaponicus, and Histioteuthis bonnellii corpuscula. Histioteuthis?miranda may have been collected by the whales much further south than the Azores. Species not recorded previously in the diet of sperm whales in the North Atlantic are Ommastrephes bartrami, Gonatus steenstrupi, Histioteuthis?miranda, H. bonnellii corpuscula, H. meleagroteuthis, Discoteuthis laciniosa, Mastigoteuthis species, Chiroteuthis species,?Helicocranchia, Liocranchia reinhardti, and?Liguriella.

Description: Abstract The Boreoatlantic gonate squid Gonatus fabricii is the most abundant squid in the offshore arctic and subarctic waters of the northern Atlantic. Adults are common in midwater while juveniles occur in surface waters close to the continents. As part of a research project focussing on the interactions among fish stocks off West Greenland we examined squid collections sampled with small pelagic nets in summer 1989 and in summer and autumn 1990 off Southwest Greenland. G. fabricii was by far the most abundant cephalopod species caught. We recorded a total of 698 juvenile specimens. During the summer cruise in 1989 the mantle lengths varied from 6 to 35 mm (n = 84); in summer 1990 they ranged from 10 to 48 mm (n = 542) with significantly larger body sizes in the southern part of the region. In autumn 1990 the mantle lengths ranged from 19 to 64 mm (n = 72) with largest animals again at the southern sampling sites. The data suggest growth rates for juvenile G. fabricii off West Greenland of 4 to 5.5 mm per month between July and November 1990. Résumé L'encornet atlantoboréal (Gonatus fubricii) est l'encornet pélagique le plus abondant des eaux arctiques et subarctiques de l'Atlantique. Les adultes se trouvent habituellement dans les couches de profondeur moyenne, et les juvéniles se trouvent en surface et proche de zone littorale. Parallèlement à une étude des stocks de poissons à l'ouest du Groënland, nous avons étudié les encornets pris avec des petits filets pélagiques en été 1989 et en été et automne 1990. G. fabricii fût le céphalopode le plus abondant, avec 698 juvéniles échantillonnés. En été 1989, les longueurs du manteau étaient de 6 à 35 mm (n = 84); en été 1990, les longueurs étaient de 10 à 48 mm (n = 542), et la taille du corps était significativement plus importante au sud de la région échantillonnée. En automne 1990, les longueurs du manteau étaient de 19 à 64 mm (n = 72), et les animaux les plus grands se trouvaient encore dans le secteur sud. Les données suggèrent un taux de croissance d'entre 4 et 5,5 mm par mois pour les juvéniles de G. fabricii sur la côte sud-ouest de Groënland pour la période de juillet à novembre 1990.

Description: Horizontal distribution of myctophid fishes were studied from two transects in the Arabian Sea in 1987. Species numbers exhibited a south-north decline in diversity, with only half of the fish taxa occupying the northeastern region. Diaphus arabicus was the dominant species both in the south and north. All recorded myctophid fish species migrate in a diel pattern, residing during daytime at depths of extremely low oxygen levels (〈0.1 ml O2 1−1) and foraging in the oxygen-rich surface layer at night. Feeding patterns were determined for the six most abundant myctophid species. All species appeared to be opportunistic predators that prey on a comparatively narrow food spectrum consisting principally of small to medium sized copepods. Numerically, non-calanoid copepods (with Oncaea conifera and O. venusta dominating) made up to 70% of the diet of D. arabicus and Bolinichthys longipes. Of the 26 calanoid copepod species identified from the six myctophid taxa, the genera Euchaeta, Pleuromamma and Candacia generally dominated in the stomachs, with P. indica constituting between 21 and 95% (by numbers) of the calanoid copepod prey.

Description: Particulate fluxes of aluminium, cadmium, cobalt, copper, iron, manganese, nickel, phosphorus, lead, vanadium and zinc in the northeast subtropical Atlantic Ocean have been determined from sediment trap samples collected between 1 December 1986 and 30 April 1987 at 1020 and 4120 m below the ocean surface. The fluxes of most elements (except Cd and P) show small variations between the different layers, and are closely associated with the vertical transport of aluminium. Elemental composition and flux rates suggest that aerosol loadings from northeast trade winds are the major contributor of these elements to depositing material. Extremely low fluxes of copper, lead and zinc also indicate that anthropogenic perturbations are of insignificant importance in this region.

Description: Within the framework of the JGOFS Pilot Study in 1989 mesozooplankton (0.2–20 mm) was sampled by means of a Hydro-Bios multinet in five depth strata (0–25, 25–50, 50–100, 100–200, 200–500 m) during four Lagrangian drift experiments of 8–14 days' duration at 18, 33, 46 and 58°N, to follow the seasonal progress of the phytoplankton spring bloom development in the northeast Atlantic. Mesozooplankton standing stock, measured as dry weight and ash-free dry weight, increased by a factor of about 6 from 18 to 58°N. Day/night differences amounted to 10–20% of the average and were—with one exception at 18°N—not statistically significant. Using the data on weight-specific respiration rates measured by colleagues on the same cruise, the ingestion rates and potential community grazing of mesozooplankton on phytoplankton within the upper 100 m of the water column were calculated. During all four drift experiments, quasi-steady-state conditions were observed in phyto- and zooplankton standing stock, primary production and daily sedimentation at 100 m depth. The maximum potential grazing rate by mesozooplankton accounted for about half of the daily primary production. Since sedimentation of fresh phytoplankton was negligible, it is concluded that the grazing pressure exercised by mesozooplankton together with micro- and nanozooplankton was responsible for keeping the phytoplankton standing stock at a more or less constant level during the investigated spring bloom in the four areas. Particle flux was thus dominated by zooplankton faecal material.

Description: Accurate congener-specific determination of chlorobiphenyl congeners (all 209 congeners) is finally possible with the use of multidimensional gas chromatography-electron-capture detection techniques. The effectiveness of this technique for environmental analyses is enhanced by ultraclean laboratory practices, non-destructive extraction and clean-up steps and the use of low-volume, high-efficiency HPLC separation for various classes of organic contaminants. In the light of these new developments conventional procedures for chlorobiphenyl analysis are evaluated.

Description: The productivity regime and size structure of phytoplankton are described for three different epipelagic systems in the Arabian Sea during the inter-monsoon period in spring 1987: (1) the coast of Oman; (2) the central Arabian Sea; and (3) the shelf off Pakistan. These results are related to the functioning of the specific ecosystem. Off the coast of Oman, the transition from a surface maximum of autotrophic biomass and production to a more oligotrophic system, with a chlorophyll subsurface maximum, was observed. Concomitantly, the size spectrum changed towards a higher significance of picoplankton. In the central Arabian Sea, a typical oligotrophic system with a pronounced subsurface maximum of autotrophic biomass and primary production was encountered. Here, the epipelagic system could be divided into two distinct sub-systems: the surface layer “regenerated” production, the predominance of picophytoplankton and minor losses due to sedimentation, thus a “closed” system; and the subsurface maximum layer at the nutricline characterized by higher sedimentation losses and more diatoms. Both sub-systems showed about the same productivity, the turnover in the surface layer having been much greater than in the subsurface maximum. The system on the shelf off Pakistan is seen as a decay stage of the open ocean system when water from offshore is transported onto the shelf during the onset of monsoon winds.

Description: Hydrographic data of temperature, salinity, oxygen, nitrate, phosphate, and silicate at 81 stations with 435 samples on 3 sections between the Azores, the Grand Banks of Newfoundland, and the Bermuda Islands are used to determine the mixing of water masses by optimum multiparameter analysis over the depth range 100–1500 m. The method optimally utilizes all information from our hydrographic data set by solving an overdetermined set of linear mixing equations for all parameters using the method of least squares residuals. It is shown that the method gives quantitative information on the influence of the various water masses of the western North Atlantic. The Gulf Stream and the North Atlantic Current appear as broad bands transporting large amounts of Western North Atlantic Central Water at their warm flank. Western Subarctic Intermediate Water and Shelf Water supplied by the Labrador Current and containing significant amounts of Labrador Current Water are found on their inshore side. The area of the Azores front is found in the vicinity of the Comer Seamounts, where the uniform water mass distribution of the Sargasso Sea changes into a more complex structure that reflects the influence of water masses originating in the Labrador Sea. Small-scale structures, like eddies or Gulf Stream rings, are also detectable by this analysis method. Comparison with dynamic height analysis supports the circulation pattern of the North Atlantic Current as a continuation of the Gulf Stream, and of the southeastward flowing Azores Current originating in the area of the Southeast Newfoundland Rise.

Description: Measurements made with satellite-tracked buoys drogued in different layers between the sea surface and 30-m depth under homogeneous winter conditions in the North Sea allow analysis of the Ekman currents under a large variety of wind conditions. The experiment lasted from November 20, 1991, until February 29, 1992. The first 4 weeks of this period, during which the buoys stayed close together, are used to determine the Ekman stresses. The total current field is a superposition of barotropic currents due to sea level variations and Ekman currents. The classical Ekman theory is not able to describe properly the observed deflection of the currents to the right of the wind direction and their decay with depth. This deflection is 10° near the sea surface and increases to approximately 50° in 25-m depth. The relation between wind stress and the stress field in the interior of the water is given by a tensor, which describes the rotation and the variation of the stress with increasing depth. The concept of eddy viscosity is applicable, if a viscosity tensor is used to relate stress and vertical shear. The viscosity tensor is a function of the vertical coordinate only and is independent from the wind stress. It shows maximum values in 15- to 20-m depth and may be due to Langmuir circulation cells. Further studies are needed to determine the physics of this tensor. Its magnitude in the interior of the mixed layer exceeds 1000 cgs units. Consequently, Ekman currents are weak and may not be the dominant currents within the mixed layer.

Description: Deployment of devices which record timing and magnitude of food ingestion in two wandering albatrosses Diomedea exulans at sub-Antarctic Marion Island shows that feeding occurred both at night and during the day, but with most ingestion events (70%) occurring during daylight hours . Seventy-six per cent of the estimated mass of food was ingested during the day. Earlier works concluded that foraging occurred mostly during the night. We suggest that noctumal foraging represents mostly capture of live prey close to the water surface, Daytime foraging is suggested to be mainly for moribund prey that has floated to the surface. Duration of foraging trips and timing of arrival back at the nest are similar to those reported elsewhere. The arrival of females soon after dawn is considered to be a consequence of a reluctance to land on the island at night. Differences in the temporal pattern of male and female arrivals may reflect sex-specific foraging patterns.

Description: A sigma-coordinate, primitive equation ocean circulation model is used to explore the problem of the remnant generation of trapped waves about a tall, circular, isolated seamount by an incident oscillatory barotropic current. The numerical solutions are used to extend prior studies into the fully nonlinear regime, and in particular to quantify and interpret the occurrence of residual circulation. Specific attention is also devoted to the dependence of the resonance and rectification mechanisms on stratification, forcing frequency, and choice of subgrid-scale viscous closure. Resonantly generated trapped waves of significant amplitude are found to occur broadly in parameter space; a precise match between the frequency of the imposed incident current and the frequency of the trapped free wave is not necessary to produce substantial excitation of the trapped wave. The maximum amplification factors produced in these numerical solutions, O(100) times the strength of the incident current, are consistent with previous studies. In the presence of nonlinear advection, strong residual currents are produced. The time-mean circulation about the seamount is dominated by a strong bottom-intensified, anticyclonic circulation closely trapped to the seamount. Maximum local time-mean current amplitudes are found to be as large as 37% of the magnitude of the propagating waves. In addition to the strong anticyclonic residual flow, there is a weaker secondary circulation in the vertical-radial plane characterized by downwelling over the top of the seamount at all depths. Maximum vertical downwelling rates of several tens of meters per day occur at the summit of the seamount. The vertical mass flux implied by this systematic downwelling is balanced by a slow radial flux of mass directed outward along the flanks of the seamount. Time-mean budgets for the radial and azimuthal components of momentum show that horizontal eddy fluxes of momentum are responsible for transporting net radial and azimuthal momentum from the far field to the upper flanks of the seamount. There, Coriolis and pressure gradient forces provide the dominant balances in the radial direction. However, the Coriolis force and viscous effects provide the primary balance for the azimuthal component.

Description: The individual marking of flying and flightless birds has a long history in ornithology. It is the only technique which is cheap, simple and effective, yielding results on bird migration, age-specific annual survival and recruitment. Consequently, hundreds of thousands of birds are annually ringed worldwide. Unfortunately, researchers all too often tend to neglect problems associated with rings and tags. In Antarctic penguins, flipper bands have been used extensively by a variety of nations, and banding is an integral part of the Council for the Conservation of Antarctic Marine Living Resources' (CCAMLR) monitoring programme (Standard method A4). This programme suggests that mortality in penguins wearing bands can be attributed to either (a) prey species availability, (b) predation, (c) weather conditions or (d) other. In this paper, we have attempted to quantify energetic costs associated with wearing a flipper band. For that purpose, freshly caught Adelie penguins (n = 7) were introduced, in Antarctica, into a 21 m long still-water tunnel, where their behaviour and energy consumption were determined via observation and gas respirometry. Birds were either immediately marked with a flipper band and tested in the tunnel for ca 2 h, and then taken out and tested again after removal of the band, or vice-versa. Flipper bands significantly (ANOVA, p = 0.006) increased the power input of Adelie penguins during swimming by 24 % over the speed range of 1.4 to 2.2 m S-', from 17 W kg-' to 21.1 W kg-' (n = 115 and 157 measurements, respectively). The implications of banding on foraging performance and sunival of penguins are discussed. Implantable passive transponders could help overcome such problems.

Description: Crossing studies revealed an intraspecifìc sterility barrier on the level of zygote formation between Japanese Sphaerotrichia divaricata and isolates of the same species from the Northeast Pacific and the North Atlantic. Because no consistent morphological differences exist between sporophytes from Japan and other areas, we propose not to distinguish the intersterile populations as different species. Japanese Sphaerotrichia and isolates from a recently detected population in the Étang de Thau, French Mediterranean coast, are interfertile. The crossing studies support the assumption that this Mediterranean population is a recent introduction from Japan.

Description: Tests on the effects of two herbivore groups (littorinid snails and gammarid amphipods), on algal succession in high intertidal tidepools dominated by Fucus distichus showed that the grazer groups exert different grazing pressures on the algae. The differences can be related to the feeding morphologies ofthe two grazer guilds. The scraping, microphagous littorinid snails prevent the establishment of both micro- and rnacroalgae at the microscopic level. The biting, macrophagous gammarid amphipods are ineffective at grazing microalgae and prostrate macroalgae from the substratum, but exert a considerable influence on the erect macroalgae which escape littorinid grazing. Despite differences in feeding mechanisms, the magnitude of the effect of the two grazer groups on the canopy cover of macroalgae is similar.

Description: In April 1990, 488 marine fish, belonging to 30 species from central Philippine waters, were investigated macroscopically for the occurrence of parasites in their flesh and for anisakid nematodes in their body cavity. Twenty-four fish were found to be infected by 1 of 4 different types of parasites. Unidentified Microspora were found in 4 host species from different families. Plerocercoids of the trypanorhynchid cestode Otobothrium penetrans occurred in the flesh of hemirhamphids and belonids only. Adult nematodes of the genus Philometra were found in the garfish Tylosurus crocodilus. The only parasite found which might be transferable to warm-blooded animals was the L-III stage of Anisakis sp. from the body cavity and the muscle of Muraenesox cinereus. The risk of human infections by parasites through consumption of raw marine fish in the central Philippines therefore is considered to be low.

Description: The reconstruction of ancient sediment fluxes is based on the assumptions that young sediment is generally unconsolidated, has the greatest areal exposure and thus has the greatest probability of being eroded. Young sediment is therefore recycled more rapidly than old sediment which is more consolidated and has a smaller areal exposure. This assumption is the fundamental principle underlying the theory of sediment recycling. We assume that on a global scale the sedimentary system is in steady state and has a mass that remains constant because most younger sediments are derived from cannibalization of older sediments through erosion. This implies that gains of sediment mass from weathering, erosion, and deposition of igneous and crystalline metamorphic rocks are exactly offset by losses to subduction and metamorphism. The general decline of sediment mass with age is approximated by a simple exponential decay y=Ae-bt where y is the remnant of the original sediment flux at time t, that would be observed today after t m.y. of recycling at a constant rate of erosion b (“average recycling proportionality parameter” of Veizer and Jansen, 1985), and a constant depositional rate, A (the rate at which sediment is being deposited at present) . The new total sediment mass for the Phanerozoic is 2082.6×1021g. Based on a least squares fit of an exponential decay curve to the data, we have determined the average zero-age flux rate of Phanerozoic sediment to be 5.756×1021g m.y.-1 and the average rate of sediment recycling to be -2.062×10-3 m.y.-1. New estimates of the mass of Proterozoic and Archaean sediments are also presented; these are 845.5×1021g and 15.0×1021g for the masses of Proterozoic and Archaean sediments respectively. Because neither rocks of a particular lithology or age can be selectively protected from erosion, it is possible to reconstruct mass-age distributions for different lithologies. Detrital rocks dominate the sedimentary system in terms of mass, and can be regionally confined as a closed system. The recycling rate of detrital rocks can be used on both global and regional scales to reconstruct past sediment fluxes of both detrital and chemically or biologically precipitated materials.

Description: The sediments recovered at Deep Sea Drilling Project Sites 362 and 532 on Walvis Ridge Abutment Plateau and at Site 530 in the southeastern Angola Basin record long-term changes in the rates of upwelling. Deposition of opaline silica and organic carbon increased from latest Miocene to latest Pliocene then declined to present. The sediments display light-dark cycles. The dark cycles contain more terrigenous material and represent glacials. During the Late Miocene the productivity maxima were characteristic of glacial maxima in the Antarctic. Since the beginning ofthe Pliocene productivity maxima have occurred during interglacials. The most likely causes of these changes are: 1) desiccation and reflooding of the Mediterranean. The desiccation drew the ITCZ to its most northerly position. After reflooding the Mediterranean had a positive fresh-water balance until about 2.5 Ma, when it changed to its present negative balance and lagoonal circulation. The period during which productivity increased along the southwest African margin corresponds to the time when the Mediterranean had a positive fresh-water balance and estuarine circulation. During this time the Mediterranean supplied no intermediate water to the North Atlantic. The decline in productivity off southwest Africa corresponds to the time when lagoonal circulation developed in the Mediterranean and, as at present, its outflow forms a major intermediate water mass. During glacials the more dilute saline Mediterranean outflow resulted in the expansion of nutrient-poor North Atlantic Intermediate Water (NAIW) at a higher level in the ocean. The NAIW replaced AAIW in the South Atlantic during glacials. Upwelling along Southwest Africa may have increased as a result of increased wind stress, but the upwelled water was NAIW, and did not result in increased productivity. 2) growth of the Antarctic and Northern Hemisphere ice caps. During the Late Miocene growth of the Antarctic ice cap forced northward migration of the subtropical highs and Intertropical Convergence Zone (ITCZ). These changes in atmospheric circulation may have initiated productive upwelling over the Walvis Abutment Plateau. As Northern Hemisphere glaciation was initiated, the Earth changed from a unipolar to a bipolar glaciated state. This forced southward migration of the ITCZ and an increase in the intensity of the southeast trade winds. 3) closing of the Central American Straits. The resulting salinization of the North Atlantic forced increased production of North Atlantic Deep Water (NADW) and Antarctic Bottom Water (AABW). The production of NADW resulted in nutrient export from the North Atlantic and development of the contrast between nutrient-rich southern and nutrient-poor northern intermediate and deep water masses. The combination of all these changes is probably responsible for the observed pattern of change in productivity. Hay and Brock's (1992) explanation of lessened productivity during glacials being due to upwelling of nutrient-poor NAIW rather than AAIW remains a viable hypothesis.

Description: The mass-balanced paleogeographic reconstructions technique determines the thickness of the rock eroded from the source areas to supply sediment to the sedimentary basins. The thickness of this eroded overburden and the time of its erosion are valuable inputs for calculations of the thermal history of the rocks and the maturation of hydrocarbons.

Description: The present ocean is thermally stratified. The waters become colder with depth, and the great mass of ocean deep water is near 2°C-almost the same as that of surface waters in the polar regions. The idea that the waters have a polar origin goes back to Benjamin Thompson (1800)(Count Rumford). He reasoned that the cold waters of the interior of the ocean must form by sinking in the polar regions and must drive poleward flow of surface waters. The idea was refined by Alexander von Humboldt(1814), who noted that the density of sinking cold polar waters must exceed the density of more saline waters in lower latitudes.

Description: Regurgitations were collected from 41 black-browed albatross adults feeding chicks at Bird Island (54°S 38°W), South Georgia in February 1986. The samples were sorted into recognisable food categories and weighed. Cephalopods were identified by means of the lower beak, or in some cases the gladius, and allometric equations were used to calculate mantle length and wet body weight represented by beaks. The samples contained 35.5%Euphausia superba, 30.9% cephalopods and 27.1% fish, by weight. A total of 21 samples contained recognisable cephalopod remains and 20 contained specimens that could be identified. In all, 50 cephalopod specimens, representing an estimated 6,866 g wet weight, were identified. The diet was dominated in terms of numbers, weight and percent occurrence by the ommastrephid squidMartialia hyadesi, and in most cases the entire squid was present with only partial digestion of the skin and arm armature. The cranchiid squidGaliteuthis glacialis was the only other cephalopod of numerical importance but no soft parts were present suggesting that, although significant in the diet of the adults, this species was not being fed to chicks. One specimen each ofGonatus antarcticus, Chiroteuthis sp.,Histioteuthis sp. B. and the octopodidPareledone polymorpha were also present. The cephalopod composition of the diet corresponded closely with a collection made 10 years earlier. The commonest species in the bird's diet,M. hyadesi, has not been found in net and jig samples at South Georgia although it has been taken from the Antarctic Polar Frontal Zone to the west of the Island. The presence of almost complete, undigested, specimens ofM. hyadesi in the bird's diet indicates that it occurs relatively close to South Georgia.M. hyadesi preys largely on myctophid fishes, which themselves prey on small zooplankters, so a significant component of the black-browed albatross diet depends on a food chain which largely by-passesE. superba.

Description: The accumulation of parasites in a fish host is modelled as a function of the total amount of prey consumed. The accumulated parasite load is then expressed as a function of fish length so that the asymptotic growth, L∞, of any population of commonly infected fish can be estimated. Estimates of L∞ are obtained for orange roughy (Hoplostethus atlanticus), albacore tuna (Thunnus alalunga) and the New Zealand southern arrow squid (Nototodarus sloanii).

Description: Reproductive biology of the tropical sepioid cephalopod Idiosepius pygmaeus was investigated in wild specimens and in individuals maintained in aquaria through the adult life span. This species produced multiple egg batches over 80% of the observable adult weight range, indicating a coordination of reproductive and somatic growth. Reproductive output was consistent within, but variable between, individuals. Oocyte synthesis and maturation occur continuously after sexual maturation has been reached. Senescence and death are not related to an exhaustion of reproductive potential. On average, captive female I. pygmaeus with access to unlimited food produced 640 eggs in 11 batches over 18 d. When reproductive output was expressed as a ratio of dry female body weight, on average, specimens had incorporated five times their body weight into eggs and egg coatings. Under food stress, captive specimens laid fewer eggs but maintained egg size and periodicity of egg laying. Food stress had no effect on either laying duration or weight at death. This study provides further evidence that terminal spawning modes are not ubiquitous amongst cephalopods.

Description: WHILE ammonites and all other ectocochleate cephalopods became extinct, nautiloids survived relatively unchanged from the Ordovician, suggesting that they are unusually well adapted to their niche. Here we obtain high-resolution tracks of Nautilus positions and depths, combined with telemetered jet pressures, which clarify both its lifestyle and economics. Nautilus is more active in nature than in captivity1, but its energy costs are lower than projected2,3. Viewing Nautilus as 'vertic', rather than benthic, resolves this contradiction. Records show that the cost of transport is the same in any direction within a vertical plane. Living on a reef face swept by a lateral current means that vertical movements4,5 sample large areas for chemical trails. A detected trail can be followed upcurrent in the slow-moving boundary layer, but no effort is wasted on horizontal movement without good prospects for food; long-range movements are downcurrent and made by drifting. Once fed, a Nautilus can reduce its energy costs by moving to deeper, cooler waters, where a single meal can last for months.

Description: Gonadal index and maturity stages of the Brazilian squid Loligo sanpaulensis were analysed on a monthly basis. Squid were caught in coastal waters off the Cabo Frio region, Brazil, between 1987 and 1988 at depths ranging from 30 to 60 m using an otter trawl with 10 m footrope and 45 mm cod-end mesh size. Field data analysis showed that development of the nidamental gland and testis was closely related (r 〉 0.9) to body size and maturity stage in the population. Mature individuals are recruited into the population twice a year. Size at first maturity was estimated to be 50 to 55 mm mantle length (ML) for males and 55 to 60 mm ML for females. Indirect evidence suggests that the final phases of the maturity process in females occur abruptly at some point after that size, and that recruitment of juveniles follows spawning and subsequent mortality or emigration of adults from the sampling area. Spawning is likely to take place in late summer and late winter.

Description: Census of cephalopods incidentally caught by boat seine operated along the west coast of Suruga Bay (Japan) aiming at larval anchovy and sardine (shirasu), were made during the years 1988, 1990 and 1991. The faunulae for these three years contained 10 species of decapods and 3 species of octopods, excluding 1 unidentified loliginid and 3 octopods. Either of Loligo edulis or L. japonica were the most frequent and abundant every year followed by Todarodes pacificus and then Inioteuthis japonica. Occurrences of oceanic species seem to be closely related to the behavior of the Kuroshio. All records of cephalopods hitherto reported from Suruga Bay were assembled: The catalogue lists 20 species of Sepioidea, 4 Myopsida, 31 Oegopsida, 1 Cirrata and 13 Incirrata (69 in all).

Description: The Octopodidae occur in virtually all benthic marine habitats; however, species in the family show little overt morphological differentiation. Subfamilies are currently defined by the presence or absence of an ink sac and the number of sucker rows (the presence of an ink sac and a single row of suckers are primitive characters) (Voss, 1988b); subfamily depth ranges arc cited in the diagnoses. Examination of external octopodid morphology through principal components analysis reveals that octopodid morphology correlates with geographic distribution. Low-latitude, shallow-water octopuses typically have narrower bodies and larger suckers on longer arms than do deep sea and high-latitude species. Sucker size inversely correlates with depth distribution, as studies of sucker functional morphology predict (Kier & Smith, 1990). The same characters contribute in a very similar manner to the discrimination of species when grouped by subfamily and when grouped by mean depth distribution. That depth distributions, which correlate with morphology and with the loss of the ink sac, contribute to the definition of these subfamilies, suggests that the subfamilies constitute phenetically similar rather than monophyletic groups. Cladistic analysis is required to reassess octopodid phylogeny.

Description: Octopodid classifications have been traditionally, and are currently, based on a few readily apparent characters. ln this analysis, I examine methods that have contributed to octopodid classifications from a cladistic perspective that emphasizes the recognition of monophyletic groups, and I apply parsimony algorithms to the data set reported by Voss (1988a) for the Octopodidae. I reject current and previous subfamily classifications of the Octopodidae as having created paraphyletic groups. Use of the category subfamily should be avoided, as it implies our knowledge of octopodid evolution has reached Ievei that is as yet unattained. To further our knowledge of octopod phylogeny, we must define primitive and derived characters states by objective criteria, consider only monophyletic species groups in our analyses and expand the range of characters considered. Analysis of the data set compiled for cladistic analysis reveals that characters of the radula, anterior digestive system and skin change in concert. These associated character changes may indicate underlying functional relationships that have been unsuspected.

Description: The cephalopod fauna of the seamounts, guyots and shallow banks consists of following main groups of species: I. Bottom and near-bottom species that permanently live on seamounts; 1 A shallow-water species inhabiting the coastal zone and the shelf, they are found mosly on the Saya de Malha Bank (Indian Ocean); 1 B-Lower sublittoral and upper bathyal species. 2. Near-bottom and benthopelagic species that spawn on the bottom but arise into midwater. 3. Nerito-oceanic species living as paralarvae and juveniles in the midwater but spawn on or over the bottom (3A) or near the surface over the tops or slops (3B). 4. lnterzonal vertical migrators advected by the currents over the seamounts at night and descending to the bottom at day. 5. Non-migrating pelagic species advected by the currents on the tops or slopes of seamounts. 6. Pelagic nektonic squids that avoid areas over the summits. A special thalassobathyal cephalopod fauna distinct from that of continental slopes do not appear to be present. With respect to the cephalopod fauna the seamounts are the "islands" in the sense of MacArthur and Wilson (1967). The mode of the formation of its fauna may be explained only by the dispersionistic, not by the vicarionistic paradigm.

Description: Four spent females of deep-sea pelagic gonatid squid Gonatopsis octopedatus, dorsal mantle length 24-39 cm, were caught in the 0-50 m layer of the Okhotsk Sea over the depths of 92-126 and approximately 3300 m. Two alike but smaller (12-13.5 cm) females were caught at the surface of the Japan Sea over the depths of 3000-3300 m. They were degenerated, combjelly-like in consistence, most of the arm armature was lost, the oviducts were empty or contained not more than 3-5 eggs up to 4.0-4.3 mm in length. On the contrary, mature males were not degenerated, with most arm hooks and suckers present. The gelatinous degeneration in females begins rather early, at 11 or 111 maturity stages, but at very different sizes. In this period the feeding stops, as degenerated females cannot catch prey. It is supposed that females spawn and juveniles hatch in deep layers, all the eggs are spawned in a short time, and then the females come passively to the surface and die. The difference in size · between females from the two seas may be caused by difference in productivity between very productive Okhotsk Sea and less productive Japan Sea.

Description: Capture and manipulation of prey is the primary function of the arnis in cephalopods, but they also take on various other prehensile functions as well as propulsive ones (e.g. 'walking’ in octopus). In many instances they act as visual signal effectors as well. The entire arm crown can be involved in concerted actions, or individual pairs of arnis (or an individual arm in the case of certain hectocotyli) can act in a discrcte manner. This paper discusses the problem of arm identity and homology in order to provide a basis for the comparison of arm action patterns and arm postures in different cephalopod groups. Emphasis is placed on data derived from the morphogenetic pathway that leads from a uniform embryonic anlage, through subdivision into distinct arm rudiments, to the differentiation of arms. These data Support the homology between the arm crowns of decapods and octopods. Furthermore, there is good evidence for the homology of arm pairs at three positions: dorsal arms, ventral arms. ventrolateral arms (=tentacles of decapods).

Description: In der Saison 1991/92 wurden erneut Seen in den Vestfold Hills (Wilkesland, Ost-Antarktis) untersucht. Ekho Lake ist hypersalin, heliothermal und meromiktisch; die größte Tiefe beträgt 42 m, die Salinität in diesem Bereich 180 %0. Entsprechend den unterschiedlichen Salzgehalten gibt es dort mindestens 3 Schichten, und die dazwischen liegenden Grenzflächen wirken wie Einwegspiegel und sammeln durch Reflektion nach unten die Sonneneinstrahlung. So wurde in der mittleren Schicht maximal + 18° C gemessen; während des antarktischen Winters fällt in den unteren Schichten die Temperatur nicht unter +13°C. Die Oxykline liegt in 24 m Tiefe. Organic Lake ist nur maximal 7.2 m tief, hat aber ebenfalls drei Schichten mit unten maximal 235 %0 Salinität. Während Ekho Lake normalerweise zufriert, gibt es auf dem Organic Lake nur sehr selten eine Eisbedeckung. Die Temperaturbedingunggnen sind hier auch wesentlich ungünstiger als bei Ekho Lake: selbst im Januar haben Tiefen unter 2 m noch negative Temperaturen. Aber die 1 m Schicht erreichte 16.5°C. Organic Lake hat einen Gehalt an gelöster organischer Substanz zwischen 23 und 45 mg/l-1. Der durchschnittliche Gehalt an OOC liegt dagegen bei Ekho Lake um 15 mg/l-1. (...)

Description: The Late Proterozoic Mozambique Belt in East Africa is reviewed, using new geochemical and other data. This review leads to the following tectonic interpretation. A first collision, between 750 and 800 Ma ago, after the obduction of the Baragoi and associated ophiolites of north-central Kenya, produced intense regional recumbent fabrics and structures, a trans-Mozambique Belt stretching lineation, crustal thickening and metamorphism reaching granulite-facies in the lower crust. Uplift and erosion were followed by closure of a second oceanic area, obduction of the West Pokot ophiolite and collision along the West Pokot suture, possibly about 580 Ma ago. This second collision produced strong within-plate deformation (Baragoian-Barsaloian) especially in N-S dextral shear zones over 100 km east of the West Pokot suture. The shear zones are associated with late Barsaloian within-plate granites. It is inferred that eastward subduction led to the successive accretion of plates to an eastern foreland, perhaps represented by Malagasy, culminating in the collision of east and west Gondwana.

Description: During the Eifelian and early Givetian, isolated mud mounds were established in a shallow basin, predominantly characterized by calcareous mudstone deposition, in the eastern Anti-Atlas of Morocco. The shapes, lithologies and faunas of these mounds stand in marked contrast with those of nearby contemporaneous, more widespread stromatoporoid/coral biostromes and small carbonate platforms adjacent to shallow shelves. With one exception, the mounds are totally exhumed, perfectly exposing their original morphologies. The smaller mounds are asymmetrical, with steeper northeastern and eastern (35–75°) than southwestern and western flanks (30–50°). The largest mound is almost circular and symmetrical, with scattered stromatoporoids, tabulate and rugose corals that do not form a rigid framework. Frame-builders are much rarer or absent in the smaller mounds. The nature and geographical distribution of the mounds reflects a bathymetric gradient, indicating that they formed on low-angle ramps which sloped gently into a shallow basin. A large reef mound was constructed at moderate depth, while small mud mounds accumulated in deeper water. Decrease of frame-builders and increase in pelagic organisms in the latter document the transition to a pelagic platform with reduced sedimentation at a short distance from the deepest mound.

Description: In February 1988, 60 near surface samples were taken on a track between 2°W in the English Channel, the Pentland Firth and the inner German Bight. Determinations were made on filtered and unfiltered samples. Concentrations of dissolved metals in the North Sea normalized to a salinity of 34.5 were Al 31, Cd 0.13, Co 0.13, Cu 3.4, Mn 6.2 and Ni 3.9 nM. In July 1984 the equivalent concentrations were Al 11, Cd 0.15, Co 0.15, Cu 4.3, Mn 12 and Ni 3.6 nM. Distinct regional differences were detectable which can be related to the origin of the water, differing river inputs, and solution-solid phase exchange reactions. The degree of the influence of exchange reactions was investigated through the concept of Kd, the distribution coefficient. A Kd of 105 ml g−1 for Al is consistent with other observations and explains the relatively high concentrations of dissolved Al detected in the English Channel on this cruise. The data suggest a higher Kd for Mn approaching 106 ml g−1. The high Mn Kd coupled to higher suspended sediment loads in winter may be sufficient to explain the lower concentration of dissolved Mn in winter. Comparison of concentrations across the shelf break suggests that for all the metals studied, the European Shelf is a source of dissolved metals to the deep sea. Calculations based on the limited available data indicate that this export is of similar magnitude to the fresh water input of dissolved metals.

Description: An overview is given of the multinational investigations carried out at 47°N 20°W for the period 24 April–31 May, with the main emphasis on the succession of plankton communities and the flux of organic carbon through various plankton components. The depth of the upper mixed layer decreased rapidly after 25 April, triggering the start of the spring bloom that developed within a 2-week period. Chlorophyll a stocks integrated to 80 m water depth reached peak concentrations during the first 10 days in May. The observed decline was partly due to the seasonal development, but also may have been influenced by changes in water masses associated with a cyclonic eddy. Primary production ranged from 50 to 150 mmol C m−2 day−1 with highest values in the first half of May. After the first bloom phase, dominated by diatoms, nanophytoplankton gained more importance as primary producers when silicate was depleted. Stocks of bacteria, microzooplankton and mesozooplankton increased in the second half of May. Bacterial production averaged 30% of primary production and probably metabolized a large amount of dissolved organic carbon (DOC) per day, but due to uncertain carbon conversion efficiencies total bacterial carbon consumption is difficult to estimate. Largely daily changes in the DOC standing stock could not be reconciled with the measured primmary production and are probably an expression of spatial rather than temporal variations. Microzooplankton was found to consume around 64% of primary production in the second half of May. Grazing estimates for mesozooplankton varied but seem to be small (〈5% of primary production) for most of the investigation period. The small mesozooplankton size classes (〈1 mm) dominated biomass and grazing. Vertical particulate organnic carbon (POC) flux measured by sediment traps in 150 m depth was around 9.8 mmol C m−2 day−1 representing approximately 11% of primary production. The spring bloom pulse of particle flux reached the deep ocean and benthos 4–6 weeks after the surface water peak.

Description: A new species of Siboglinum is reported from off the Tejo mouth, Portugal. It was dredged from c. 1100 m. It resembles S. atlanticum and certain other species, in having paired white glandular stripes on the forepart. In the posterior trunk region we found small gram-negative internal symbiotic bacteria. All described species of the genus Siboglinum are equipped with a single tentacle, but one of our specimens bears two tentacles.

Description: Mortality of two dogs, after exposure to water of a brackish lake on the German North Sea coast in 1990, is considered to be caused by a toxic Nodularia spumigena Mertens bloom.

Description: The distribution and behavior of tintinnids Stenosernella nucula have been measured in situ within a microlayer formed by 39 million individuals⋅liter–1 with an optical particle counting- and imaging-system. The parallel propulsions of the many animals add up and drive strong downwelling water currents. Preliminary results for swimming-speeds, -directions and organism-distributions are presented. Probably due to gyrotaxis (Kessler, 1985, 1986) or some unknown bio/physical processes the organisms are focused into their self-generated velocity profile. Similar phenomena have been described for very dense plankton cultures as “bioconvection” (Childress et al., 1975a, 1975b; Platt, 1961; Plesset and Winet, 1974; Plesset et al., 1975). The micropatches are 2–4 mm wide and 8–340 mm deep with organism concentrations up to 215 million tintinnids⋅liter–1. The flows form small convection cells similar to Langmuir- or Benard-cells with distances between the patches of 8–30 mm. At the edge of the downwelling areas water velocity increases from near zero to 2–3 mm per s over a vertical distance of less than 1 mm resulting in considerable shear. Some ecological consequences of these microturbulences and microdistributions for predator-prey relationships and particle transports in eutrophic estuaries are discussed.

Description: Altimetric data from Geosat and some critical hydrographic measurements were used to estimate in real time the mesoscale physical oceanographic environment surrounding the Joint Global Ocean Flux Study (JGOFS) 1989 North Atlantic Bloom Experiment. Three cyclonic eddies, including an exceptionally large one, evolved and interacted over the 10 weeks of observations. Subsequent analysis of all available hydrographic data confirmed the real time estimates and provided further quantitative information concerning the mesoscale and submesoscale structure of the upper ocean. Remotely sensed indicators of near-surface chlorophyll content reveal significant biological variability on these wavelengths. The altimetric and hydrographic data have been assimilated into a dynamical model to produce optimal estimates of physical fields of interest as they evolve in time for use in physical and biological process studies

Description: Most atmospheric parameters relevant to microbe dissemination into the atmosphere, including aerial transport and deposition, can be monitored by temperature and humidity, aerosols, clouds, precipitation, and wind through current meteorological and other satellite systems. A wide range of these parameters are already extracted and distributed operationally on a regional or global basis like cloudiness, cloud height, cloud motion, winds, surface temperature and atmospheric temperature profiles, and precipitation estimates, Some of these products like cloud motion, winds, and temperature profiles enter weather forecast models for initialization purposes. These models predict the global state of the atmosphere (some include precipitation and cloudiness) quite reliably for several days. Thus, an important part of the necessary technical framework for global disease spread and transmission monitoring exists.

Description: The influence of increasing amounts of surfactants on the toxicity of hydrocarbons was determined using the bioluminescence inhibition test (Microtox test). Three biogenic and three synthetic surfactants were tested against the water-soluble fractions (WSF) of crude and weathered Ekofisk oil, phenol, and naphthalene. Surfactant concentrations below 100 mg litre−1 lowered the toxicity of the WSF, indicating an antagonistic interaction reducing the toxicities of surfactants and hydrocarbons. At concentrations greater than 100 mg litre−1 the toxicity rose again and was higher than the untreated WSF. The point of reversal seemed to be the critical micelle concentration, at which the formation of oil/water emulsions is possible.