ALBERT

Description: A variety of methods were successfully applied to examine the efficacy of a modular ballast water system according to the standards as adopted by the International Maritime Organization. The ballast water treatment system had a capacity of 530 m3 h−1 consisted of a pump system, a hydrocyclone, a 50 μm mesh-size self-cleaning filter and an installation for the addition of a chemical disinfectant (PERACLEAN® Ocean). The land-based testing facility used natural sea water of high turbidity during the spring phytoplankton bloom. The mesozooplankton fraction was inspected with a standard binocular. Larger zooplankton were effectively removed with the filter; the smaller sized fraction containing larvae and nauplia were killed after chemical treatment. The phytoplankton component was monitored using flow cytometry. The huge colonies of the phytoplankton Phaeocystis globosa were disrupted in the hydrocyclone liberating the colony cells which passed as single cells through the filter. These cells remained viable but were finally killed in the secondary (chemical) step. Bacteria also passed all mechanical treatment steps unharmed but were killed in the final step. Viability tests with SYTOX Green, which were specifically designed for phytoplankton, showed that mechanical treatment did not affect the percentage of viable cells a short-term, but after several hours the viable cell counts dropped down to 70%. Phytoplankton cells recovered within a single day and formed a new dense bloom rapidly. The bacteriostatic component of the chemical disinfectant (H2O2) remained present for several days preventing regrowth of bacteria for up to 15 days after addition. In conclusion, the IMO standards were met using the modular ballast water treatment unit and the applied instruments and assays were effective and rapid tools to qualify and quantify the organisms present as well as their viability.

Description: Shells of the blue mussel Mytilus edulis remain free of fouling organisms as long as they possess an intact periostracum, and a multiple antifouling defence that comprises a ripple-like microtopography and the production of chemical antifouling compounds has been suggested previously. This study investigates the chemical defence strategy of blue mussels for the first time. Six crude extracts of the periostracum of intact shells were made using solvents of increasing polarity. These extracts were tested against common fouling organisms in laboratory based bioassays. Non-polar and moderately polar fractions showed the highest activities: the diethyl ether fraction strongly inhibited attachment of Balanus amphitrite cyprids and the marine bacteria Cobetia marina and Marinobacter hydrocarbonoclasticus. Attachment of the benthic diatom Amphora coffeaeformis was significantly reduced by the dichloromethane extract, whereas both ethyl acetate and diethyl ether fractions slowed diatom growth. These results provide the first evidence of surface bound compounds that may moderate surface colonisation.

Description: Sea level changes in the Baltic Sea are dominated by internal, short-term variations that are mostly caused by the ephemeral nature of atmospheric conditions over the Baltic area. Tides are small and their influence decreases from western parts of the Baltic Sea to the Baltic Proper. Superimposed to the large short-term sea level changes (up to few decimeters from day to day) are seasonal and interannual variations (centimeters to decimeters). This study focuses on the comparison of sea surface heights obtained from observations and from a high resolution oceanographic model of the Baltic Sea. From this comparison, the accuracy of the modeled sea surface variations is evaluated, which is a necessary precondition for the further use of the oceanographic model in geodetic applications. The model reproduces all observed Baltic sea level variations very reliably with an accuracy of 5 to 9 cm (rms) for short-term variations (up to 2 months) and 8 cm (rms) for long-term variations (〉2 months). An additional improvement of the model can be attained by including long-period sea level variations of the North Sea. The model performs well also in the case of extreme sea level events, as is shown for a major storm surge that occurred at the southern coast of the Baltic Sea in November 1995.

Description: Modern antifouling coatings use heavy metals and toxic organic molecules to prevent biofouling, the undesirable growth of marine organisms on man-made substrata. In an ongoing survey of deep-sea microorganisms aimed at finding low toxic antifouling metabolites, an actinomycete bacterium was isolated from the Pacific sediment at the depth of about 5000 m. The bacterium was closely related to Streptomyces fungicidicus (99% similarity) according to 16S ribosomal RNA sequence information. The spent culture medium of this bacterium inhibited barnacle larval attachment. Bioassay-guided fractionation was employed to isolate antifouling compounds. The ethyl acetate extract was fractionated by using an open silica gel column. Active fractions were further purified on a HPLC C18 column. Five diketopiperazines, cyclo-(L-Leu-L-Pro), cyclo-(L-Phe-L-Pro), cyclo-(L-Val-L-Pro), cyclo-(L-Trp-L-Pro), and cyclo-(L-Leu-L-Val) were isolated for the first time from a deep sea bacterium, and the structures of the compounds were elucidated by nuclear magnetic resonance spectroscopy and mass spectrometry. The pure diketopiperazines were tested for antilarval activity using the barnacle Balanus amphitrite. Effective concentrations that inhibited 50% larval attachment (EC50) after 24 h ranged from 0.10- 0.27 mM. The data suggest that diketopiperazines and other compounds from deep-sea bacteria may be used as novel antifoulants.

Description: Development of microbial biofilms and the recruitment of propagules on the surfaces of man-made structures in the marine environment cause serious problems for the navies and for marine industries around the world. Current antifouling technology is based on the application of toxic substances that can be harmful to the natural environment. For this reason and the global ban of tributyl tin (TBT), there is a need for the development of “environmentally-friendly” antifoulants. Marine microbes are promising potential sources of non-toxic or less-toxic antifouling compounds as they can produce substances that inhibit not only the attachment and/or growth of microorganisms but also the settlement of invertebrate larvae and macroalgal spores. However, so far only few antilarval settlement compounds have been isolated and identified from bacteria. In this review knowledge about antifouling compounds produced by marine bacteria and diatoms are summarised and evaluated and future research directions are highlighted.

Description: The purpose of this study was to monitor and evaluate the specific characteristics and properties of the most important water resources in Dalmatia, located in Southern Croatia, for a period of five years (1999–2003). The paper presents a detailed account of the water's chemical content, classification and concentration of salts. The bacteriological pollution levels are indicated by the total coliform bacterial levels (MPN coli/100 ml). The water characteristics are expressed by coefficients which represent the ratios between water ingredients. The Ca/Mg eq ratio, SO4/Cl eq ratio and K1, K2 for bicarbonate hardness were calculated. The hygienic characteristics of the water samples were expressed by the total coliform bacteria estimation (MPN coli/100 ml), the permanganate consumption (KMnO4) and biological oxygen demand (BOD5). Karst waters, i.e. rain waters, in Dalmatia are moderately hard, the SO4/Cl ratio is 0.38-1.6, non corrosive (K1 lower than 0.2) and not significantly mineralised (〈500 mg/L minerals). Sulfate waters are generally hard, the SO4/Cl ratio is higher than 1.6, K1 is 0.2-0.65. Marine waters are quite hard or hard, particularly at the river estuaries, the SO4/Cl ratio is lower than 0.38, and K1 is higher than 0.65. Rain water direction equation, marine direction equation and sulfate direction equation are calculated on the base of SO4/Cl ratio. The groundwater and springs in Dalmatia are less polluted than surface waters. A majority of the water observed, 24 of 42 locations, have geometric average values of MPN coli〈150/100 ml of water. This group includes the majority of springs in Dalmatia, as well as some sections of rivers studied. The highest bacteriological pollution was found at nine locations where MPN coli〉1000/100 ml. Moderate pollution was found at nine locations where MPN coli is between 150–1000/100 ml of water. The water in Dalmatia is quite safe and mainly preserves its natural properties.

Description: A study of Rossia macrosoma in Portuguese waters with emphasis on its biogeographical, biological and biochemical characteristics is presented. Approximately 1000 specimens collected in 32 cruises between 1990 and 2003 were used to determine the distribution and abundance of the species and some population biology parameters (weight, length, sex and maturation). The first biochemical characterization of the species at different stages of gonad development was made. The species was found at depths up to 860 m along the whole Portuguese coast. The sex ratio was approximately 1:1 and did not vary with depth or position along the coast (P≫0.05). Females grew larger (84:67 mm mantle length) and heavier (161:100 g total body weight) than males. Mature specimens of both sexes constituted 〈1% of all records. Immature and maturing specimens were found year round, without significant differences between female monthly distributions (P 〉 0.05). No significant difference between sexes in the distribution of maturity stages with depth or position along the coast was noted (P≫0.05). During sexual maturation there was a significant increase (P 〈 0.05) in total amino acid, protein, lipid and fatty acid contents in the gonad, but the allocation of these organic compounds from digestive gland and muscle was not evident. In the three tissues analysed, the major fatty acids were 16:0, 18:0, 18:1, 20:1, 20:4n-6, 20:5n-3 and 22:6n-3, the major essential amino acids were lysine, leucine and arginine and the major non-essential amino acids were glutamic acid, aspartic acid and serine.

Description: A visible pathological condition located in the arms and mantle of the Hubb octopus Octopus hubbsorum from the Northeast Pacific waters is described for the first time. Histological sections confirmed later stages (fibrosis) of a chronic inflammatory condition of unknown aetiology.

Description: Sexual dimorphism in size and morphology of the lower beak of the warty onychoteuthid squid Moroteuthis ingens is analysed. Beaks of maturing males exhibit a band of weak, clear cartilage across the shoulder region, while mature males exhibit a pronounced excavation of this area; the hood remains intact. Female beaks attain greater size, but relatively shorter lower rostral lengths (LRL) than those of males; they display neither the shoulder cartilage nor later erosion, but the hood is consistently eroded in mature specimens. The angle ridge in females is considerably longer than in males. Due to the difference in LRL relative to overall beak size, M. ingens beaks from predator stomachs should be sexed prior to calculating prey size using LRL; for both sexes, the LRL‐mantle length (ML) relationship is linear while the LRL‐weight relationship is exponential. Sex‐specific equations are provided for reconstructing ML and weight using LRL. Based on several incidences of male‐female pairs collected with beaks interlocked, M. ingens is postulated to mate in a head‐to‐head position, with both individuals incurring beak damage during the event.

Description: A long-synonymized species Benthoctopus normani (Massy 1907) (Cephalopoda: Octopodidae) is redescribed from material collected over 30 years by the National Oceanography Centre, Southampton and the National Museums of Scotland. It can be distinguished from other octopodid specimens found in deep waters of the Northeast Atlantic by its biserial suckers, lack of ink sac, and simple ligula, which lacks transverse ridges. Examination of the collections led to the identification of a new species of Benthoctopus from the Northeast Atlantic, which is described herein.

Description: A new method of generating two-dimensional and three-dimensional cloud fields is presented, which share several important statistical properties with real measured cloud fields.Well-known algorithms such as the Fourier method and the Bounded Cascade method generate fields with a specified Fourier spectrum. The new iterative method allows for the specification of both the power spectrum and the amplitude distribution of the parameter of interest, e.g. the liquid water content or liquid water path. As such, the method is well suited to generate cloud fields based on measured data, and it is able to generate broken cloud fields. Important applications of such cloud fields are e.g. closure studies. The algorithm can be supplied with additional spatial constraints which can reduce the number of measured cases needed for such studies. In this study the suitability of the algorithm for radiative questions is evaluated by comparing the radiative properties of cloud fields from cloud resolving models of cumulus and stratocumulus with their surrogate fields at nadir, and for a solar zenith angle of 0◦ and 60◦. The cumulus surrogate clouds ended up to be identical to the large eddy simulation (LES) clouds on which they are based, except for translations and reflections. The root mean square differences of the stratocumulus transmittance and reflectance fields are less than 0.03% of the radiative budget. The radiances and mean actinic fluxes fit better than 2%. These results demonstrate that these LES clouds are well described from a radiative point of view, using only a power spectrum together with an amplitude distribution.