ALBERT

Description: The deep ocean floor between the Clarion and Clipperton fracture zones (NE equatorial Pacific) has the highest known manganese nodule abundance in the world oceans. A detailed analysis of MR1 (Mapping Researcher 1, 11–12 kHz) sonar images and free-fall grab data in the Korean manganese nodule field areas reveals a close relationship between side-scan sonar characteristics of the seafloor and manganese nodule abundance. Eight sonar facies are identified based on back-scattering intensity and distribution patterns. These sonar facies can be interpreted as (1) volcanic seamounts (facies I-1), (2) bounding faults of abyssal hills (facies I-2 and II-1), (3) lava flows or volcanoclastic mass-flow deposits around the volcanic seamounts (facies I-3 and II-2), (4) crests of abyssal hills (facies II-1), (5) abyssal troughs between abyssal hills (facies III-1), (6) relatively flat areas (facies II-3 and III-2). In the areas where facies II-1 (abyssal hill crests with thin sediment cover) and II-3 (relatively flat areas draped by thin sediments) are dominant, manganese nodules occur abundantly. In contrast, zones comprising facies III-1 (abyssal troughs with thick sediment cover) and III-2 (relatively flat areas covered by thick sediments) are characterized by low abundance of manganese nodules. This relationship between distribution of sonar facies and manganese nodule abundance implies that (1) the qualitative difference in acoustic reflectivity of long-range sidescan sonar with some ground truth data is useful for regional assessment of manganese nodule occurrence over wide areas in a reasonable time, and (2) seafloor topography and sediment thickness are important controlling factors for regional occurrences of manganese nodules.

Description: The torque generated by a rotating joint comprises the useful force exerted by the joint on the external environment, and both the magnitude and distribution of torque through the step cycle during walking are important variables in understanding the mechanics of walking. The mechanics of the American lobster (Homarus americanus) and snow crab (Chionoecetes opilio) during walking were modelled to examine the relative roles of flexor versus extensor apodeme–muscle complexes, investigate which legs of these decapods likely contribute the greatest to locomotion, determine scaling effects of torque generation, and assess the relative roles of various model variables on torque production. Force generated along the length of the apodeme by the muscle was modelled based on apodeme surface area, muscle stress, and muscle fibre pinnation angle. Torque was then calculated from this estimated force and the corresponding moment arm. The flexor apodeme–muscle complex is calculated to generate consistently greater forces than the extensor, and generally this results in flexor torque being larger than extensor, though the snow crab does illustrate the opposite in two of its legs. This greater torque generation in flexion suggests that, in addition to the pushing of the trailing legs, the pulling action of the leading legs may play a significant role, at least during lateral walking. Leg 4 of both species appears to generate greater torques and thus provide the greatest forces for locomotion. Torque generation as a function of body size shows a second order response due to the increase in apodeme surface area. The pinnation angle of the muscle fibre is found to be insignificant in force generation, apodeme surface area (representing muscle cross sectional area) likely plays the most influential role in total force production, and moment arm controls the distribution of this force through the step cycle. Muscle stress remain a largely unknown quantity however, and may significantly affect both magnitude and distribution through step cycle of forces, and thus torque. Despite the uncertainty associated with the muscle stress parameter, the modelled results fit well with previously published force measurements.

Description: Palaeoenvironmental records from permafrost sequences complemented by infrared stimulated luminescence (IRSL) and 230Th/U dates from Bol'shoy Lyakhovsky Island (7320'N, 14130'E) document the environmental history in the region for at least the past 200 ka. Pollen spectra and insect fauna indicate that relatively wet grass-sedge tundra habitats dominated during an interstadial c. 200–170 ka BP. Summers were rather warm and wet, while stable isotopes reflect severe winter conditions. The pollen spectra reflect sparser grass-sedge vegetation during a Taz (Late Saalian) stage, c. 170–130 ka BP, with environmental conditions much more severe compared with the previous interstadial. Open Poaceae and Artemisia plant associations dominated vegetation at the beginning of the Kazantsevo (Eemian) c. 130 ka BP. Some shrubs (Alnus fruticosa, Salix, Betula nana) grew in more protected and wetter places as well. The climate was relatively warm during this time, resulting in the melting of Saalian ice wedges. Later, during the interglacial optimum, shrub tundra with Alnus fruticosa and Betula nana s.l. dominated vegetation. Climate was relatively wet and warm. Quantitative pollen-based climate reconstruction suggests that mean July temperatures were 4–5 C higher than the present during the optimum of the Eemian, while late Eemian records indicate significant climate deterioration.

Description: The Space Information Laboratory (SIL) of the Tropical Center for Earth and Space Studies of the University of Puerto Rico at Mayagu¨ ez (UPRM) has been collecting and processing satellite data since December of 1996. Satellite imagery from the Advanced Very High Resolution Radiometer (AVHRR) and the Sea viewing Wide Field of view Sensor (SeaWiFS) provides us with a new understanding of phytoplankton dynamics in the Caribbean region. SeaWiFS shows the intrusion of waters into the eastern Caribbean Sea from the Orinoco River during fall and from the Amazon River during spring–summer. Strong coastal upwelling in Venezuela produced by the trade winds during winter– spring is detected with the AVHRR. The satellite data suggest that these seasonal events may play an important role in phytoplankton fertilization of the eastern Caribbean Sea. SeaWiFS and hydrological data are also combined to evaluate the impact of hurricanes on phytoplankton distribution. The development of models for estimation of ocean primary productivity using SeaWiFS and AVHRR data is now in progress.

Description: The hydrographic conditions in the south-east Atlantic were investigated during the cruise of R/V Poseidon in April 1999. The area of investigation covers the two major eastern boundary currents of the Southern Atlantic and its convergence in the Angola-Benguela Frontal Zone (ABFZ). Hydrographic measurements have been carried out in combination with current measurements and are supplemented with remote sensing data of sea surface temperature (SST) and wind stress. The Angola Current transported in its surface part less saline water from the great rivers in the north towards the ABFZ. At the same time, south of the front, strong coastal upwelling in the Benguela was observed. At the beginning of April 1999 the ABFZ was found at an unusual southern position. The rapid dynamic response of the ABFZ to wind forcing is discussed on the basis of satellite SST images combined with hydrographic measurements.

Description: Changes apparent in the arctic climate system in recent years require evaluation in a century-scale perspective in order to assess the Arctic's response to increasing anthropogenic greenhouse-gas forcing. Here, a new set of century- and multidecadal-scale observational data of surface air temperature (SAT) and sea ice is used in combination with ECHAM4 and HadCM3 coupled atmosphere-ice-ocean global model simulations in order to better determine and understand arctic climate variability. We show that two pronounced twentieth-century warming events, both amplified in the Arctic, were linked to sea-ice variability. SAT observations and model simulations indicate that the nature of the arctic warming in the last two decades is distinct from the early twentieth-century warm period. It is suggested strongly that the earlier warming was natural internal climate-system variability, whereas the recent SAT changes are a response to anthropogenic forcing. The area of arctic sea ice is furthermore observed to have decreased similar to8 x 10(5) km(2) (7.4%) in the past quarter century, with record-low summer ice coverage in September 2002. A set of model predictions is used to quantify changes in the ice cover through the twenty-first century, with greater reductions expected in summer than winter. In summer, a predominantly sea-ice-free Arctic is predicted for the end of this century.

Description: Multiple antifouling strategies of marine organisms may consist of combinations of physical, chemical and mechanical mechanisms. In this study, the role of surface microtopography (〈500 mum) of different marine organisms, such as Cancer pagurus , Mytilus edulis , Ophiura texturata and the eggcase of Scyliorhinus canicula , has been investigated as a possible component of their defence systems. High resolution resin replicates of these natural surface structures were exposed to natural fouling in field experiments. Abundances of recruits were determined and compared to those on untextured, but otherwise identical, control surfaces to quantify the influence of the different microtopographies on fouling rates. Antifouling effects of microtopographies varied with type of microtopography and coloniser species. The surface microtopography of C. pagurus significantly rejected macrofoulers. The surface structures of the eggcase and O. texturata had repellent effects on microfoulers. Barnacle settlement was temporarily reduced on surface microtopographies of M. edulis and the eggcase. These results emphasise the promising non-toxic antifouling properties of microtextured surfaces

Description: Using thin-layer chromatography (TLC) bioautography, a total of 58 extracts from various organs (aerial parts, leaves, flowers, fruits, roots) of 16 Turkish plants were tested for their antibacterial, antifungal, acetylcholinesterase inhibitory, antioxidant, and radical scavenging activities. The hexane, CHCl3/CH2Cl2, water, and total MeOH extracts were used. No activity was observed against two Gram-negative bacteria (Escherichia coli and Pseudomonas aureginosa) and the yeast Candida albicans. However, 23 plant extracts, mostly the CHCl3/CH2Cl2 and H2O-solubles, inhibited the growth of all five Gram-positive bacteria tested, Micrococcus luteus, Bacillus subtilis, Bacillus cereus, Staphylococcus aureus, and Staphylococcus epidermidis. Of the active extracts, the CHCl3-soluble of the roots of Putoria calabrica (L. fil) DC (Rubiaceae) displayed the highest antibacterial potential. The majority of the CHCl3/CH2Cl2 crude extracts also appeared to inhibit acetylcholinesterase on TLC plates at 100 µg/spot concentration. Particularly active samples were the middle polarity extracts (CHCl3/CH2Cl2) of the leaves of Rhododendron smirnovii Trautv., R. ponticum L., and R. ungernii Trautv. (Ericaceae). β-Carotene, β-carotene/linoleic acid mixture, and 2,2-diphenyl-l-pieryhydrazyl (DPPH) solutions sprayed onto TLC plates were used for detecting antioxidant and radical scavenging properties of the crude extracts. Antioxidant and radical scavenging activities were found to be predominant in highly polar extracts. The water-solubles of all Rhododendron (Ericaceae) and Phlomis (Lamiaceae) species presented the most significant activity.

Description: A lab-scale composting experiment was carried out using vegetable and flower stalks waste to study the effectiveness of ligno-cellulolytic microorganisms (LCMs) obtained from the previous isolation on composting process, especially on enhancement of biodegradation rate of these organic materials. The addition of LCMs to compost showed promised to be a valuable asset by rendering timely benefits in efficiency, maturity, and quality of the composting. This was evidenced by a significant increase of temperature, O2 consumption and CO2 emission, and population density of LCMs in compost mass compared with that of biotic (addition of culture of horse feces) and abiotic (1% molasses amendment) treatments, as well as control trial. The phytotoxicity assay showed that the substrate became mature after 60 days’ composting. The LCMs inoculation enhanced the biodegradation of the composting materials as evidenced by an increasing screening ratio (1.2 cm sieve pore) of 34.5% in the treated trail, compared with that of control, which elucidated that big advantage of adding selected inoculants over other treatment, and screening ratio is a reasonable index to compare the quality of different compost. However, the inoculation seemed to have no significant effect on the moisture content, pH, and the final organic carbon of the composting materials.

Description: The egg mass and embryos of the ommastrephid squid Nototodarus gouldi McCoy, 1888 are reported for the first time, their identity confirmed by mitochondrial 16S rDNA sequence determination. The egg mass is a free‐floating gelatinous sphere of at least 1.5 m diameter and contains an estimated several thousand randomly distributed eggs; similar egg masses recorded from north‐eastern New Zealand waters of 1.0–2.0 m diameter are reported. Observed fluctuations in populations for this and other squid species may be a partial result of trawl damage to the egg masses.

Description: Siliceous and calcareous sponges commonly are treated with acid to remove the spicules prior to embedding and cutting for histological investigations. Histology of spiculated sponge tissue represents a challenging problem in sponge histotechnology. Furthermore, fluorescence in situ hybridization (FISH), a key method for studying sponge-associated microbes, is not possible after acid treatment. For a broad range of siliceous sponge species, we developed and evaluated methods for embedding in paraffin, methylmethacrylate resins, LR White resin and cryomatrix. Different methods for cutting tissue blocks as well as mounting and staining sections also were tested. Our aim was to enable histological investigations and FISH without prior removal of the spicules. To obtain an overview of tissue and skeleton arrangement, we recommend embedding tissue blocks with LR White resin combined with en bloc staining techniques for large specimens with thick and numerous spicules, but paraffin embedding and subsequent staining for whole small specimens. For FISH on siliceous sponges, we recommend Histocryl embedding if the spicule content is high, but paraffin embedding if it is low. Classical histological techniques are used for detailed tissue examinations.

Description: Fault tolerance is an important aspect in the development of control systems for multi-legged robots since a failure in a leg may lead to a severe loss of static stability of a gait. In this paper, an algorithm for tolerating a locked joint failure is described in gait planning for a quadruped robot with crab walking. A locked joint failure is one for which a joint cannot move and is locked in place. If a failed joint is locked, the workspace of the resulting leg is constrained, but legged robots have fault tolerance capability to continue walking maintaining static stability. A strategy for fault-tolerant gaits is described and, especially, a periodic gait is presented for crab walking of a quadruped. The leg sequence and the formula of the stride length are analytically driven based on gait study and robot kinematics. The adjustment procedure from a normal gait to the proposed fault-tolerant crab gait is shown to demonstrate the applicability of the proposed scheme.

Description: The family Forskaliidae (Siphonophora, Physonectae) contains a single genus, Forskalia, whose species are, in general, poorly known. However, in recent years many Forskalia specimens have been collected by scuba divers or by using submersibles. These specimens have allowed a comprehensive review of the species within the genus to be carried out. In addition two new species are described.

Description: Permafrost deposits were studied along the Olenyeksky and the Arinsky distributaries in the western Lena delta using a multidisciplinary approach that included sedimentological, mineralogical, stable-isotope, and paleoecological analyses in order to reconstruct the Late Quaternary landscape and environmental history of this Northeast.

Description: This review provides an overview of the importance of beach accumulations of macrophytes and other organic beach-cast material on the ecology of sandy beach ecosystems. It describes the composition of these allochthonous subsidies, their abundance on beaches in relation to seasonal, lunar, tidal and spatial trends, their decomposition and utilisation by bacterial, meio- and macrofaunal communities. The paper then analyses the community structure and the species succession in both macrophyte wrack and carrion and reports the most important findings on individual wrack-inhabiting species (amphipods, isopods, dipterans). Other aspects, such as feeding and microclimatic preferences of certain species and their interactions in wracks, are also discussed. Links to vertebrate species and other secondary consumers that exploit beach-cast macrophytes and carrion as trophic resource are considered, and the importance of wrack in recycling nutrients to nearshore coastal ecosystems is stressed. The beneficial and detrimental effects of organic beach-cast material on both plants and animals of beach and nearshore communities and on the geomorphology of coastal beach-dune systems are pointed out. Another section is dedicated to human use of beach-cast macrophytes through harvesting of economically important species and of other stranded material through its exploitation for traditional reasons. The effects of harvesting on local faunal communities and on the stability of the dunes is discussed. A final section of the paper includes the positive and negative effects of man-made debris on sandy-beach ecosystems and briefly reviews the major findings.

Description: Current antifouling technologies rely on metal-based paints, but due to their toxicity, an expected worldwide ban of organotin-containing paints is now prompting the quest for safe and effective alternatives. One of these is antifouling coatings whose active components are naturally occurring compounds in marine organisms. A number of laboratory bioassays has been designed to search for antifouling compounds. However, there is no evidence to date that these assays provide results reproducible through ecologically realistic field experiments. Natural concentrations of the extracts from the Brazilian seaweeds Laurencia obtusa and Stypopodium zonale were tested in the laboratory through the 'mussel test' and in the field through the 'phytagel method' in order to compare the efficiency of these methods in assessing antifouling activity. L. obtusa extract significantly inhibited fouling in both the laboratory and field assays, while S. zonale stimulated fouling in both assays. Major compounds from the extracts were identified. The findings suggest that the 'mussel test' is a reliable time and cost-saving screening method for antifouling substances, although field assays are more sensitive for detection of their activity spectrum.

Description: Development of biomass and density in experimental monospecific stands of Fucus serratus, F. vesiculosus and F. spiralis was followed on Helgoland (southern North Sea) in plots with three different initial germling densities. As biomass increased over time, considerable mortality occurred. Mortality was significantly higher in stands with higher initial densities, leading to similar final densities. The self-thinning law, which describes boundary conditions for combinations of biomass and density of plants, was refuted in two ways for all three Fucus species: (i) several data points on a bi-logarithmic plane lay considerably above self-thinning lines with conventional parameters from terrestrial plant ecology; however, ‘overall boundaries’ (i.e. a self-thinning line that constrains all lines found) from terrestrial plant ecology were not significantly transgressed, (ii) lines fitted with principal components analysis (PCA) revealed a positive correlation between stand biomass and density. Reasons are proposed why seaweeds generally seem to show higher maximum biomass for a given density than terrestrial plants. Size distributions at the end of the experiment were positively skewed with high Gini coefficients that lay in the range found in other seaweed studies. Inequality decreased with individual mass and increased with density. Gini coefficients were highly correlated with other measurements of inequality (coefficient of variation, skewness).

Description: The Baltic Sea Experiment BALTEX is the European regional project of GEWEX. The aim of BALTEX is to improve the knowledge of the water and energy cycle of the Baltic Sea including its catchment area (the BALTEX area). In this study the NCEP/NCAR reanalysis data (Kalnay et al. Bull. Am. Meteorol. Soc., 1996, 77, 437–471) are used to derive the mean atmospheric water budget over the BALTEX area. For this purpose the horizontal water vapour fluxes are calculated. In the long-term mean (here 1948 – 2000) the vertically integrated divergence of these fluxes must balance evaporation minus precipitation. The latter two are provided by the NCEP/NCAR reanalyses. The water budget over the BALTEX area is, however, not closed. An error estimation is performed. The divergence of the water vapour flux is corrected due to the mass balance correction technique (Alestalo, Tellus, 1981, 33, 360–371). Large differences are obtained between the precipitation given by the NCEP/NCAR reanalysis and by the analysis of the observations by Rubel and Hantel (Meteorol. Atmos. Phys., 2001, 77, 155–166). With these analysed precipitation data and the corrected divergence of the water vapour fluxes the imbalance of the water vapour budget could be remarkably reduced.

Description: Precipitation and evaporation over the Baltic Sea are calculated for a one-year period from September 1998 to August 1999 by four different tools, the two atmospheric regional models HIRLAM and REMO, the oceanographic model PROBE-Baltic in combination with the SMHI (1 × 1)° database and Interpolated Fields, based essentially on ship measurements. The investigated period is slightly warmer and wetter than the climatological mean. Correlation coefficients of the differently calculated latent heat fluxes vary between 0.81 (HIRLAM and REMO) and 0.56 (SMHI/PROBE-Baltic and Interpolated Fields), while the correlation coefficients between model fluxes and measured fluxes range from 0.61 and 0.78. Deviations of simulated and interpolated monthly precipitation over the Baltic Sea are less than ±5 mm in the southern Baltic and up to 20 mm near the Finnish coast for the one-year period. The methods simulate the annual cycle of precipitation and evaporation of the Baltic Proper in a similar manner with a broad maximum of net precipitation in spring and early summer and a minimum in late summer. The annual averages of net precipitation of the Baltic Proper range from 57 mm (REMO) to 262 mm (HIRLAM) and for the Baltic Sea from 96 mm (SMHI/PROBE-Baltic) to 209 mm (HIRLAM). This range is considered to give the uncertainty of present-day determination of the net precipitation over the Baltic Sea.

Description: The aim of this article is to give a contextual description of personnel selection in Europe, and to highlight some typical features and recent trends in practice and research. We begin with describing the socio-economic environment in which European personnel selection is embedded. Next, we take a closer look at the institutional settings in which personnel selection takes place and its underlying principles. Consequently we review and discuss recent empirical evidence on selection practices and methods, and interpret observed characteristics in terms of contextual differences. Looking at recent changes in the European organizational environment, we note that selection practices exhibit a certain degree of conservatism, and that selection research and theory are slow in addressing new issues. The lack of responsiveness to the changing context is attributed to a continued adherence to the "right man in the right place" paradigm. As an alternative paradigm we propose the "theatre model" of selection, which seems more suitable to tune personnel selection to current contextual demands. Finally, we present a view of the future agenda for European selection research.

Description: Cold seep environments such as sediments above outcropping hydrate at Hydrate Ridge (Cascadia margin off Oregon) are characterized by methane venting, high sulfide fluxes caused by the anaerobic oxidation of methane, and the presence of chemosynthetic communities. Recent investigations showed that another characteristic feature of cold seeps is the occurrence of methanotrophic archaea, which can be identified by specific biomarker lipids and 16S rDNA analysis. This investigation deals with the diversity and distribution of sulfate-reducing bacteria, some of which are directly involved in the anaerobic oxidation of methane as syntrophic partners of the methanotrophic archaea. The composition and activity of the microbial communities at methane vented and nonvented sediments are compared by quantitative methods including total cell counts, fluorescence in situ hybridization (FISH), bacterial production, enzyme activity, and sulfate reduction rates. Bacteria involved in the degradation of particulate organic carbon (POC) are as active and diverse as at other productive margin sites of similar water depths. The availability of methane supports a two orders of magnitude higher microbial biomass (up to 9.6 2 10 10 cells cm m 3 ) and sulfate reduction rates (up to 8 w mol cm m 3 d m 1 ) in hydrate-bearing sediments, as well as a high bacterial diversity, especially in the group of i -proteobacteria including members of the branches Desulfosarcina/Desulfococcus , Desulforhopalus , Desulfobulbus , and Desulfocapsa . Most of the diversity of sulfate-reducing bacteria in hydrate-bearing sediments comprises seep-endemic clades, which share only low similarities with previously cultured bacteria.

Description: Pollen data from a Levinson-Lessing Lake sediment core (74°28'N, 98°38'E) and Cape Sabler, Taymyr Lake permafrost sequences (74°33'N, 100°32'E) reveal substantial environmental changes on the northern Taymyr Peninsula during the last c. 32000 14C years. The continuous records confirm that a scarce steppe-like vegetation with Poaceae, Artemisia and Cyperaceae dominated c. 32 000–10300 14C yr BP, while tundra-like vegetation with Oxyria, Ranunculaceae and Caryophyllaceae grew in wetter areas. The coldest interval occurred c. 18000 yr BP. Lateglacial pollen data show several warming events followed by a climate deterioration c. 10500 14C yr BP, which may correspond with the Younger Dryas. The Late Pleistocene/Holocene transition, c. 10300–10000 14C yr BP, is characterized by a change from the herb-dominated vegetation to shrubby tundra with Betula sect. Nanae and Salix. Alnus fruticosa arrived locally c. 9000–8500 14Cyr BP and disappeared c. 4000–3500 14Cyr BP. Communities of Betula sect. Nanae, broadly distributed at c. 10000–3500 14Cyr BP, almost disappeared when vegetation became similar to the modern herb tundra after 3500–3000 14Cyr BP. Quantitative climate reconstructions show Last Glacial Maximum summer temperature about 4°C below the present and Preboreal (c. 10 000 14C yr BP) temperature 2–4°C above the present. Maximum summer temperature occurred between 10 000 and 5500 14C yr BP; later summers were similar to present or slightly warmer.

Description: A compilation of data on the elemental composition of marine phytoplankton from published studies was used to determine the range of C:N:P. The N:P ratio of algae and cyanobacteria is very plastic in nutrient-limited cells, ranging from 〈5 mol N:mol P when phosphate is available greatly in excess of nitrate or ammonium to 〈100 mol N:mol P when inorganic N is present greatly in excess of P. Under optimal nutrient-replete growth conditions, the cellular N:P ratio is somewhat more constrained, ranging from 5 to 19 mol N:mol P, with most observations below the Redfield ratio of 16. Limited data indicate that the critical N:P that marks the transition between N- and P-limitation of phytoplankton growth lies in the range 20–50 mol N:mol P, considerably in excess of the Redfield ratio. Biochemical composition can be used to constrain the critical N:P. Although the biochemical data do not preclude the critical N:P from being as high as 50, the typical biochemical composition of nutrient-replete algae and cyanobacteria suggests that the critical N:P is more likely to lie in the range between 15 and 30. Despite the observation that the overall average N:P composition of marine particulate matter closely approximates the Redfield ratio of 16, there are significant local variations with a range from 5 to 34. Consistent with the culture studies, lowest values of N:P are associated with nitrate- and phosphate-replete conditions. The highest values of N:P are observed in oligotrophic waters and are within the range of critical N:P observed in cultures, but are not so high as to necessarily invoke P-limitation. The C:N ratio is also plastic. The average C:N ratios of nutrientreplete phytoplankton cultures, oceanic particulate matter and inorganic N and C draw-down are slightly greater than the Redfield ratio of 6.6. Neither the analysis of laboratory C:N:P data nor a more theoretical approach based on the relative abundance of the major biochemical molecules in the phytoplankton can support the contention that the Redfield N:P reflects a physiological or biochemical constraint on the elemental composition of primary production.

Description: We investigated the effects of local nutrient enrichment, among-population variation in quality, and within-plant variation in quality on growth, development, and food consumption (total amount of food ingested) of the marine isopod Idotea baltica when fed Fucus vesiculosus. We found that the proximity of fish farms increased carbon/nitrogen ratio, but did not change the concentration of phlorotannins in the F. vesiculosus thallus. Algal diets taken from sites close to or far from fish farms did not affect the growth, development, or total amount of food ingested of I. baltica. Therefore, eutrophication may not necessarily decrease the level of plant resistance. We found that different F. vesiculosus beds vary in quality and led to differences in total amount of food ingested and production efficiency of I. baltica. The variation in quality of F. vesiculosus in different locations may generate variance in grazing pressure between the belts. Idotea baltica was most sensitive to within-plant variation, as the isopods grew more and had higher production efficiency on apical than basal parts of F. vesiculosus. Idotea baltica did not compensate for the lower quality of basal parts by increasing consumption. This may indicate that the low quality of the basal thallus is related to higher levels of secondary metabolites and not to lower levels of soluble sugars or nitrogen that might have encouraged compensatory consumption. Our results suggest that within-plant variation in the quality of the F. vesiculosus is more important for herbivores than possible environmental variation caused by eutrophication.

Description: Small-angle phase functions (0.05° 〈 θ 〈 20°) have been measured for turbid samples that were then used in a Monte-Carlo theoretical light-scattering model. The measured phase function yields excellent agreement between model predictions and long-path tank measurements.

Description: The study investigates perspectives of the parameter estimation problem with the adjoint method in eddy-resolving models. Sensitivity to initial conditions resulting from the chaotic nature of this type of model limits the direct application of the adjoint method by predictability. Prolonging the period of assimilation is accompanied by the appearance of an increasing number of secondary minima of the cost function that prevents the convergence of this method. In the framework of the Lorenz model it is shown that averaged quantities are suitable for describing invariant properties, and that secondary minima are for this type of data transformed into stochastic deviations. An adjoint method suitable for the assimilation of statistical characteristics of data and applicable on time scales beyond the predictability limit is presented. The approach assumes a greater predictability for averaged quantities. The adjoint to a prognostic model for statistical moments is employed for calculating cost function gradients that ignore the fine structure resulting from secondary minima. Coarse resolution versions of eddy-resolving models are used for this purpose. Identical twin experiments are performed with a quasigeostrophic model to evaluate the performance and limitations of this approach in improving models by estimating parameters. The wind stress curl is estimated from a simulated mean stream function. A very simple parameterization scheme for the assimilation of second-order moments is shown to permit the estimation of gradients that perform efficiently in minimizing cost functions.

Description: Using dimensional analysis and finite-element calculations, several relationships that relate features of indentation loading and unloading curves to the hardness, the elastic modulus and the work of indentation are extended to conical indentation in elastic-plastic solids with various angles. These relationships provide new insights into indentation measurements. They may also be useful to the interpretation of results obtained from instrumented indentation experiments.

Description: One kinds of glycolipid (SBI) have been isolated from the marine brown alga Sargassum hemiphyllum (Turn.) Ag. The structures of SBI have been determined as the sodium salt of 1-0-acyl-3-0-(6′-sulfo-α-D-quinovopyrannosyl) glycerol (acyl: tetradecanoyl, pentadecanoyl, 11-hexadecenoyl, hexadecanoyl, 10,13-octadecadienoyl, 9-octade cenoyl, 15-metylheptadecanoyl and 11-eicosenoyl 17:1.5:19:153:1:19:1:2) on the basis of chemical and spectral evidence and GC-MS analysis, respectively. Four constituents of the SBI were new compounds [the sodium salt of 1-0-(11″-hexadecenoyl)-3-0-(6′-sulfo-α-D-quinovopyrannosyl) glycerol, the sodium salt of 1-0-(10″,13″-octadecadienoyl)-3-0-(6′-sulfo-α-D-quinovopyrannosyl) glycerol, and the sodium salt of 1-0-(15″-metylhexadecenoyl)-3-0-(6′-sulfo-α-D-quinovopyrannosyl) glycerol, and the sodium salt of 1-0-(11″-eicosenoyl)-3-0-(6′-sulfo-α-D-quinovopyrannosyl) glycerol]. All compounds were isolated from marine brown alga for the first time.

Description: Seafloor morphology and ferromanganese nodule occurrence were studied using a multibeam side scan sonar (SeaBeam, 2000) and a deep-sea camera system in the Korea Deep-sea Environmental Study (KODES) area, northeast equatorial Pacific. Seafloor morphology and nodule abundance are highly variable even in this small study area. The NNE-SSW oriented hills are parallel and about 100–200 m high. Valleys are very flat-floored, while hilltops are rugged with depressions of tens of meters. Cliffs to about 100 m bound the valleys and the hills. The study area can be classified into three types based both on nodule occurrence and seafloor morphology, mostly G- and B-types and some M-type. G-type is characterized by high nodule abundance, ubiquitous bioturbation, and flat seafloor morphology, while B-type is characterized by irregular-shaped nodules, variable nodule abundance, occurrence of giant nodules and sediment lumps, rugged bottom morphology with depressions, and white calcareous surface sediments. Medium nodule abundance and a generally flat seafloor characterize M-type. G-type occurs mostly in the valley regions, while B-type is on the hilltop areas. M-type is located between the hilltop and the valley. Tectonic movement of the Pacific plate resulted in the elongated abyssal hills and cliffs. The rugged morphology on hilltops resulted from erosion and redistribution of surface siliceous sediments on hilltops by bottom currents, outcropping of underlying calcareous sediments, and dissolution of the carbonate sediments by corrosive bottom water undersaturated with CaCO3. Sediment eroded from the hills, which is relatively young and organic-rich, is deposited in the valleys, and diagenetic metal supply to manganese nodules in the valley area is more active than on the hills. We suggest that tectonic movement ultimately constrains morphology, surface sediment facies, bottom currents and sediment redistribution, bioturbation, thickness of the sedimentary layer, and other conditions, which are all interrelated and control nodule occurrence. The best potential area for mining in the study area is the G-type valley zones with about 3–4 km width and NNW-SSE orientation.

Description: The use of precautionary management actions within a fisheries context has generally been limited to reducing fishing mortality. By the use of quantitative models, overfishing thresholds can be determined and actions can be taken to reduce the probability of further population declines and to allow rebuilding. Within this context, four management approaches have been defined (i.e., preventive approach, corrective approach, precautionary approach, and precautionary principle) on the basis of levels of uncertainty in the information used to make decisions and the potential cost of errors as a result of those decisions. In this paper, I apply these approaches to developing a precautionary and adaptive habitat management framework. Fishing effort metrics are used to develop estimates of the area of seafloor impacted by fishing, and thresholds are proposed to trigger specific types of management actions. Information needs include the cumulative area impacted by all gears, the distribution of habitats and diversity of key taxa, effects of gears on habitat and patterns of diversity, and linkages between habitat and the dynamics of exploited populations. Incentives for the fishing industry that will improve the information available to make decisions and reduce the level of precaution required for managing exploitation of wild populations are discussed. This framework is a starting point for management agencies to develop precautionary and adaptive habitat management programs that promote both the sustainability of exploited populations and the maintenance of biological diversity.

Description: Due to the ephemeral nature of the atmospheric conditions over the Baltic Sea, the flow field is highly variable, and thus, changes in the resulting circulation and upwelling are difficult to observe. However, three-dimensional models, forced by realistic atmospheric conditions and river runoff, have reached such a state of accuracy that the highly fluctuating current field and the associated evolution of the temperature and salinity field can be described. In this work, effects of remote and local atmospheric forcing on circulation and upwelling in the Baltic Sea are investigated. Changes in the characteristics of the large-scale atmospheric wind field over the central and eastern North Atlantic can be described by the North Atlantic Oscillation (NAO). The NAO is related to the strength and geographical position of weather systems as they cross the North Atlantic and thus has a direct impact on the climate in Europe. To relate the local wind field over the Baltic Sea to the large-scale atmospheric circulation, we defined a Baltic Sea Index (BSI), which is the difference of normalised sea level pressures between Oslo in Norway and Szczecin in Poland. The NAO is significantly related to the BSI. Furthermore, the BSI is highly correlated with the storage variation of the Baltic Sea and the volume exchange through the Danish Sounds. Based on three-dimensional model calculations, it is shown that different phases of the NAO during winter result in major changes of horizontal transports in the deep basins of the Baltic Sea and in upwelling along the coasts as well as in the interior of the basins. During NAO+ phases, strong Ekman currents are produced with increased up- and downwelling along the coasts and associated coastal jets, whereas during NAO− phases, Ekman drift and upwelling are strongly reduced, and the flow field can almost entirely be described by the barotropic stream function. The general nature of the mean circulation in the deep basins of the Baltic Sea, obtained from a 10-yr model run, can be described by the depth integrated vorticity balance derived from the transport equation for variable depth.

Description: Cephalopod stocks are of increasing economic importance. Cephalopod fisheries show marked inter-annual fluctuations unrelated to fishery landings and effort. Their population dynamics, particularly recruitment, are thought to be strongly susceptible to changes in environmental conditions. This arises in part from the short life cycle, resulting in poor buffering of the population against changing conditions. These characteristics make traditional approaches to stock assessment and fishery management inappropriate. GIS offers a tool to improve understanding of spatio-temporal trends in abundance and facilitate rational management. A cephalopod fishery geographical information system for Northeast Atlantic waters (CFGIS-NEA) was developed. The system covers the area from 28.0° W to 11.0° E, and 34.5° N to 65.5° N. It was designed for investigating cephalopod resource dynamics in relation to environmental variation. It is based on Unix Arc/Info, and PC ArcView, combined with the statistical software package S-PLUS and supported by a database in Microsoft Access. Environmental data (e.g. sea surface temperature and salinity, sea bottom temperature and salinity, and bathymetric data), cephalopod fishery, survey and biological data, from a variety of sources, were integrated in the GIS as coverages, grids, shapefiles, and tables. Special functions were developed for data integration, data conversion, query, visualisation, analysis and management. User-friendly interfaces were developed allowing relatively inexperienced users to operate the system. The spatial and temporal distribution patterns of cephalopod abundance by species, the spatial and temporal relationships between cephalopod abundance and environmental factors, and the spatial and temporal patterns of cephalopod fishing activity were analysed using a combination of visual (qualitative) and quantitative methods. Predictive empirical models, such as GAMs (generalized additive models), were developed for modelling cephalopod abundance using environmental variables.

Description: All seven known resident Arctic cephalopods were identified in the collections of the German RV Polarstern (1991, 1993, 1995, 1998) in the waters around Svalbard, northwards from the Kara Sea, in the Laptev and western East Siberian seas: sepia lids Rossia palpebrosa (depths 96–362 m) and R. moelleri (67–101, specimens identified with question mark also at the depths of 38 and 292 m), benthic octopuses Bathypolypus arcticus (180–362 m), Benthoctopus piscatorum (1580–2000 m), and Benthoctopus sibiricus (30m, a juvenile identified with question mark), cirrate octopod Cirroteuthis muelleri (3012–3310 m), and gonatid squid Gonatus fabricii (juveniles: in midwater, 300–500 m, in fish stomachs, 946–990 m). The latter two species are definitely circumpolar and panpolar (inhabiting the whole Polar Basin). The known ranges of R. pulpebrosa, R. moelleri, and B. arcticus are extended from the eastern coasts of Severnaya Zemlya and Vilkitsky Strait to western East Siberian Sea (R. palpebrosa: 150°E) or eastern Laptev Sea (R. moelleri: 130°E, B. arcticus: 135°E), the range of B. piscatorum is extended from West Spitsbergen Island to 91°E. Although gaps still exist in the known distributions of R. palpebrosa. R. moelleri and B. arcticus (these species are considered as West-Arctic or Atlanta-West-Arctic) between the eastern boundaries of their ranges in the Asian Arctic and western boundaries in the Canadian Arctic, there are little doubt that they are in fact circumpolar and widely eurybathic in the western sector of the Arctic but in the eastern sector distributed only at depths 〉 100–200 m (except R. moelleri: to 67 m). B. piscatorum is known at yet in western Arctic only and may be not circumpolar. Benthoctopus sibiricus is the East-Arctic (definitely not circumpolar) shallow-water benthic octopus having relations with the octopods of northwestern Pacific.

Description: What is environmental enrichment? During the last several decades, zoos and aquariums have come to realize (perhaps belatedly) that animals kept in captivity need environmental enrichment for their well-being (Seidensticher & Forthman, 1998). Early zoos and aquariums tried to show as many animals as possible; hence, their exhibits were frequently small and bare to permit easy viewing, cleaning, and sterilization. Now, all have come to realize that captive animals need environmental enrichment for their health and for the education and increased expectations of visitors to zoos and aquariums.

Description: The morphological features associated with Co-rich manganese deposits, the size variations of nodules, and the occurrence of different substrates have been analyzed, to evaluate the influence of various seabed slope angles on the distribution of these features. The coverage and size of the crusts depend on their surface morphology and seabed topography, resulting in cobble-type, lineated, or step-like outcrops. Small nodules (1–4 cm in diameter) dominate all seabed slopes, with a few locations having nodules ranging from 1 to 8 or 1 to 10 cm. Sediments invariably occur as substrates for nodules and as cover for crusts, their coverage being inversely proportional to that of the nodules and crust outcrops.

Description: A semi-quantitative assessment is made of the animals observed in archived videotapes taken from the research submersible Jago, during diamond mining and exploratory surveys off the mouth of the Orange River on the west coast of southern Africa (28°15′S, 29°11′S) in November 1996. The seabed environment is described and nekton associations with substratum features are identified. The area is characterized by heterogeneity to its physical and biological struture. The variety of observed nekton is low, and communities are dominated by goby Sufflogobius bibarbatus, juvenile hake Merluccius spp. and cuttlefish Sepia spp. (on soft substrata), as well as false jacopever Sebastes capensis and kingklip Genypterus capensis (on rocky substrata).

Description: The chief host of cadmium in zinc deposits is sphalerite, the cadmium content of which depends on the type of deposit. Sphalerite from Mississippi Valley-type (MVT) deposits has high cadmium concentrations whereas sphalerite from exhalative deposits has low cadmium concentrations. The Cd content of sphalerite depends on the Cd/Zn ratio, ligand activities, and temperature of the ore-forming fluids. The combined effect of variation of temperature, pH, total activity of reduced sulfur, and activity of Cl- cannot by itself account for either Cd depletion (exhalative deposits) or Cd enrichment (MVT deposits). Variations in the Cd/Zn ratio of the fluid have a significant effect in determining that of sphalerite. Basinal brines, which can considered to be the recent equivalents of MVT fluids, have high Cd/Zn ratios, and active exhalative systems are characterized by low Cd/Zn ratios. Probably the differences in sphalerite composition between the different deposit types are less a function of temperature and ligand activities than Cd/Zn ratio of the ore-forming fluids. In the hydrothermal environment, the Cd/Zn ratio is generally not high enough to allow crystallization of cadmium sulfides (greenockite or hawleyite). The abundance of greenockite in the supergene alteration zone of hydrothermal zinc deposits can be explained on the basis of Zn scavenging by crystallizing smithsonite.

Description: A single living specimen of Stenocyathus vermiformis was collected with a grab from the distal rubble zone of a Lophelia bank at 276 m depth on the Sula Ridge, Norwegian Shelf.

Description: Recent progress in research of the global carbon cycle is reviewed and research needs for the immediate future are discussed, in light of the challenge posed to society to come to grips with the problem of man-made climate change. The carbon cycle in the oceans and on the land is reviewed, and how the atmosphere functions to couple them together. Major uncertainties still exist for any projection of the future atmospheric burden of carbon dioxide resulting from postulated emission scenarios of CO2. We present some ideas on how future policies designed to limit emissions or to sequester carbon can possibly be supported by scientific evidence of their effectiveness.

Description: Particle fluxes were measured 7 m above the sea bottom during the predisturbance, disturbance, and postdisturbance periods by using time series sediment traps attached to seven deep-sea moorings deployed in the INDEX experiment site in the Central Indian Basin. The predisturbance particle fluxes varied between 22.3 to 55.1 mg m−2 day−1. Increased and variable particle fluxes were recorded by the sediment traps during the disturbance period. The increase observed was 0.5 to 4 times more than the background predisturbance fluxes. The increases in particle fluxes (∼4 times) recorded by the sediment trap located in the southwestern direction (DMS-1) were the greatest, which could be the result of preferential movement of resuspended particles generated during the deep-sea benthic disturbance along the general current direction prevailing in this area during the experimental period. Also, the traps located closer to the disturbance area recorded greater fluxes than did the traps far away, across the Deep Sea Sediment Resuspension System path. This variability in recorded particle fluxes by the traps around the disturbance area clearly indicates that physical characteristics such as grain size and density of the resuspended particles produced during the disturbance had an important effect on particle movement. The postdisturbance measurements during ∼5 days showed a reduction in particle fluxes of ∼50%, indicating rapid particle settlement.

Description: Observations on seafloor features from subbottom profiling and seabed photography data show that the undisturbed and natural conditions before the benthic disturbance undergo a substantial change after operation of the disturber. The effects can be seen in the form of deep trenches and grooves, formed by the action of the sleds and the pumping of the sediment along its path, as well as sediment piles on either side of the track. Biological traces such as fecal coils, casts, tubes, burrows, and trails get obliterated in the areas of disturbance and resedimentation. The smooth, uniform nature of the seafloor observed in pre-disturbance phase shows microtopographic changes in and around the disturbed area as a result of sediment excavation and resettlement. Vertical mixing as well as lateral transport of sediment alter the geological, biological, physical, and chemical conditions on the seafloor, which need to be monitored over time to assess the process and the time taken for restoration of environmental conditions.

Description: Antarctic sponges are commonly fouled by diatoms, sometimes so heavily as to occlude pores employed in filter feeding and respiration. This fouling becomes heavier during the annual summer microalgal bloom. Polar and non‐polar extracts of eight species of marine sponges from McMurdo Sound, Antarctica were assayed for cytotoxicity against sympatric fouling diatoms. To identify compounds potentially released by sponges as defenses against diatom biofouling, only fractions of crude extracts that were soluble in seawater or 2% methanol in seawater were assayed. Significant bioactivity was present in seven of the eight species. Both Mycale acerata and Homaxinella balfourensis displayed moderate levels of defense against diatoms even though they are not or are only weakly chemically defended against bacteria and predators. Calyx acuarius extracts, which do have antipredator and antibacterial effects, had no effect on diatoms except at levels many fold higher than present in the intact animal. These results strongly suggest some level of specificity for chemical defenses against diatom fouling in antarctic sponges.

Description: Measurements from a dinosaur trackway are used to estimate how fast the dinosaur track makers were moving. The exercise, which is appropriate for any introductory earth-science course at the secondary-school or college level, introduces students to dimensional analysis by having them construct an empirical graph of dimensionless stride length versus dimensionless velocity. The students then estimate the dimensionless stride length from the trackway data and use the dimensionless graph to determine the speeds of the dinosaurs. Experience with the exercise indicates that even students with little quantitative background are motivated by the challenge of determining whether they could outrun the dinosaurs and often begin to appreciate the power of dimensional analysis, a concept not usually presented in introductory courses.

Description: A reassessment of the abundance of dolomite in carbonate sediments has confirmed that carbonates deposited during the past 150 Ma contain, on average, less dolomite than Proterozoic and Paleozoic carbonates. The lower dolomite content of the more recent carbonate sediments results from the increase in the deposition of CaCO3 in deep-sea sediments, and to the difficulty of dolomitizing deep-sea CaCO3 by reaction with cold, unevaporated seawater. The decrease in the rate of dolomite formation during the past 150 Ma has led to an increase in the output of oceanic Mg+2 by the reaction of seawater with clay minerals and with ocean-floor basalts. The increase in the output of marine Mg+2 into these reservoirs has been brought about by an increase in the Mg+2 concentration of seawater. During the past 40 Ma, the concentration of Mg+2 in seawater has probably increased by ∼18 mmol/kg, and probably has been accompanied by an equimolar increase in the concentration of SO4−2.

Description: The morphological features associated with Co-rich manganese deposits, the size variations of nodules, and the occurrence of different substrates have been analyzed, to evaluate the influence of various seabed slope angles on the distribution of these features. The coverage and size of the crusts depend on their surface morphology and seabed topography, resulting in cobble-type, lineated, or step-like outcrops. Small nodules (1–4 cm in diameter) dominate all seabed slopes, with a few locations having nodules ranging from 1 to 8 or 1 to 10 cm. Sediments invariably occur as substrates for nodules and as cover for crusts, their coverage being inversely proportional to that of the nodules and crust outcrops. Steeper seafloor areas have large crust outcrops exposed with no or few nodules and sediments associated with them. The intermediate slopes have a combination of nodules, sediments, and crusts in various proportions, depending on topography and gradient. Large-scale nodule occurrences, followed by sediment fields and crust outcrops on seabed slopes of 〈 3°, 3–7°, and 〉 15°, respectively, represent typical morphological distribution zones of the Co-rich manganese deposits on a seamount in the central Pacific Ocean. A transition zone between nodule-dominated fields and large crust outcrops occurs for slopes from 7° to 15°. This detailed study on distribution of Co-rich deposits gives a better understanding for purposes of their exploitation.