Volume Of Seawater Research Articles

The Behaviour of Thorium Isotopes During the Decomposition of Large Marine Particles: In vitro Experiments and Field Data

The behaviour of organic matter, trace elements and Th isotopes (232Th and 23~ has been studied during the decomposition of large marine particles under laboratory controlled conditions (Semp6r6 et al., 1998, Arraes-Mescoffet al., 1998). The sampling site (DYFAMED) is located in the Mediterraenan Sea 5 miles off Nice. Large volumes of seawater were filtered through 60 gin grids using in situ pumps at 30 m and 200 m. The particles were then distributed among different batches in sterile (0.2 I.tm filtration) seawater and left for variable incubation times (from 0 to 20 days) in the dark, at the in situ temperature and with oxic conditions. Each incubations was stopped by filtration on a 0.2 ~tm filters yielding a filtered solution and residual particles. Some samples were sterilized by gamma irradiation in order to distinguish between biotic and abiotic processes. We obtained results on the particles collected at 30 m. 23~ and 232Th were analysed on the filtered solutions and some residual particles by isotope dilution and TIMS. After 20 days of incubation, less than 1% of the 232Th initialy present on the particles is dissolved. The temporal evolution of 232Th in solution seems to mimic the temporal evolution of Mn (Arraes-Mescoff et al. 1998, fast initial dissolution and possible biologyrelated scavenging at the end of the experiment), but some Th contamination of the samples may have occured. The variations of the 23~ ratio of the filtered solutions suggest that during the experiment 23~ and 232Th have identical behaviours.

Trace Element Dissolution Rates During the Decomposition of Large Marine Particles: In vitro Experiments and the Role of Biological Activity

Large sinking marine particules play a key role in the cycle of the elements in the ocean. During their settling through the water column, they interact with the solution and small particles by aggregationdisaggregation, adsorption-dissolution, biodegradation... However, our understanding of these processes is still scarce mostly due to the lack of experimental and/or field data. Among these processes, the effect of the direct dissolution of large marine particles in response to bacterial activity is poorly constrained. An in vitro experiment has been set up in order to study simultaneously the behaviour organic and inorganic matter during the decomposition of large particles by bacteria (Semp6r6 et al., 1998; RoyBarman et aL, 1998). Here, we report results obtained for a selection of trace elements that are essential for studying the transport and fate of matter in the ocean. Aluminum is used as a tracer of the lithogenic fraction in the water column. Barium is used as a tracer of the exported production in the present ocean and as a tracer of the ocean palaeoproductivity. Manganese is sensitive to the redox conditions of the environment and precipitation of Mn oxy-hydroxides plays a key role in the scavenging of trace metals in the water column. The sampling site (DYFAMED) is located in the Mediterraenan Sea 5 miles offNice. Large volume of seawater were filtered through 60 gm grids using in situ pumps at 30 m and 200 m. The particles were then distributed among different batches in sterile (0.2 gm filtration) seawater and left for variable incubation times (from 0 to 20 days) in the dark, at the in situ temperature and with oxic conditions. Each incubations was stopped by filtration on a 0.2 lam filters yielding a filtered solution and residual particles. Some samples were sterilized by gamma irradiation in order to distinguish between biotic and abiotic processes. Filtered solutions (30 m and 200m) and some of the residual particles (30 m) were analysed by ICPMS. The percentage of dissolution (D) of an element on particles is obtained by comparison of the increase of concentration in solution and the quantity present on particles: at 30 m D ~< 2 3 % for A1, D = 41-64 % for Ba, D = 18-33 % for Mn. The labile fraction of the elements on the particles is defined as the maximum percentage of dissolution. The low labile fraction obtained for A1 support the use of A1 as litogenic matter tracer. The temporal evolutions of the concentrations in the filtered solutions show distinct behaviours for Ba and Mn. Assuming that the dissolution of the labile fraction follows a /st order kinetic, residence times (z) of labile Ba and Mn on particles are estimated based on the data collected during the first days of incubation. For Ba, z = 0.6 days at 30 m and z 2.8 days at 200 m. The temporal evolutions of Ba in the irradiated and non-irradiated samples are similar suggesting that the Ba dissolution is mainly an inorganic process. Ba in marine particules often occurs as BaSO4. The difference of residence time suggests a faster dissolution of BaSO4 at the surface compared to 200 m that is consistent with the evolution of BaSO4 cristallization states with depth. For Mn, ~ 2 days at 30 m and ~ 3 5 days at 200 m. During the first days of incubation, the temporal evolutions of Mn in the irradiated and non irradiated solutions are similar suggesting an inorganic process. After 20 days, the Mn concentration is lower in the non irradiated solutions compared to the irradiated solutions for both depths, suggesting a biology mediated precipitation of Mn oxides on the particles.

Lack of Excitation by Tsunamis of Normal Modes of Sea-surface Oscillations in Bays

—We conducted a spectral analysis of records of tsunamis following the 1993 Hokkaido Nansei-Oki earthquake and the 1983 Nihonkai-Chubu earthquake, at two tide-gauge stations in Maizuru Bay, Kyoto Prefecture. Having solved the eigenvalue problem of the proper oscillations for the bay, we compared spectral peaks between the records and theory. The fundamental mode with a theoretical period of 76 min and the third mode with 19 min were clearly identified in the observed records, however, the second mode with a theoretical period of 38 min was not detected, and there was little evidence for the fourth mode with 15 min. We conducted the same analysis for the 1993 tsunami in Saigo Bay, Shimane Prefecture, and found the third mode to be missing.¶By introducing "a water-exchange ratio" defined as the ratio of sea-water volume exchanged between the bay and the outer sea to the sum of the absolute volume of sea-surface displacement for each theoretical mode, we find that the excitation of a mode of proper oscillation depends on the value of this water-exchange ratio.

Evaluation on chemical neutron activation analysis for trace metals in seawater using magnesium oxide as the preconcentration agent

Attempts have been made to employ magnesium oxide as the preconcentration agent for determination of trace metal sin seawater by neutron activation analysis. Hydrous magnesium oxide can efficienthy adsorb most cationic transition metals and rare earths in a simple water system. The adsorption behavior is believed to depend mainly from the association of the cationic species of the metals with MgO 2 2− adsorbent. In seawater matrix some of the metal ions such as Hg2+, Ni2+, etc. may become inefficiently adsorbed owing to the formation of highly stable metal-chloro complexes with chloride ion. Usually the adsorption efficiencies of the metals can be recovered to be as high as the case in the simple water system if an acidified seawater (to pH≤1) is subjected to the adsorption experiment. In practice, a large volume of seawater (5 1) is stirred with a small amount of hydrous MgO (1 g). Thereafter, the trace metals adsorbed MgO is separated and taken to be neutron activated. The abundant sodium ion and ubiquitous bromide ion can be obviated by the adsorption process, thereby beneficial to the γ-spectrometry of the metals enriched on MgO.

Metalización de medidas de corrección de la intrusión marina en los acuíferos de río Vélez, río Verde y Castell de Ferro (provincias de Málaga y Granada)

The sea water intrusion process shows different dynamics in three spanish southmediterranean coastal aquifers affected by seasonal overexploitation (Rio Velez, Rio Verde and Castell de Ferro). On the base of these differences we carried out a mathematical modeling to check the effectiveness of severa1 hypothetical actions against this contaminant process. For the Rio Velez aquifer we have modeled first of al1 a total omission of flow in the river during the wet season. We conclude the sea water intrusion should be not affected noticeably. Second of al1 we have simulated a certain flow in the river during the whole year, which should reduce markedly the volume of sea water intruding this aquifer. The modeling for the Rio Verde aquifer shows that an artificial recharge (using resources from neighbouring basins) during the wet season is not an efficient action against sea water intrusion. During the dry season it should be more efficient against contamination to use the imported resources directly for irrigation than using then to recharge the system. Finally, an hypothetical stoppage of pumping in the Castell the Ferro aquifer should make sea water intrusion to disappear, but should not be efficient to wash remaining salts. So, we have simulated as well the effect of a low permeability barrier located between the detrital materials and a karstified block connected to the sea as well. This action appears as an interesting one as it should reduce the volume of sea water intrusion and inducing to an increase of seaward flow through the detrital materials, giving way to a good washing of salts.

Determination of trimethylamine oxide in seawater and small volumes of seafood tissue extract using flow injection analysis

A method is described for the indirect determination of trimethylamine oxide (TMAO) in small volumes of seawater (300 μl) and in seafood tissue extracts (100 μl). After simple TMAO reduction to trimethylamine (TMA), the samples were directly injected into the flow injection system enabling the TMAO to be measured as TMA. Calibration of the method with acidic TMAO standard solutions in the range of 10–200 μmol l −1 ( n = 10) and with seawater TMAO standard solutions in the range of 10–100 μmol l −1 ( n = 8) gave linear calibration curves ( r = 0.999 in each case). The minimum detectable level for the method was 6 μmol l −1 while using the acidic standard solutions and 2.5 μmol l −1 for seawater TMAO standard solutions. Relative standard deviations were found to be <2% in all instances.

Achieving Clean Technology in the Fish-Meal Industry by Addition of a New Process Step

Fish-meal processing plants use large volumes of seawater to unload the fish from ships. Water to fish ratios range from 5 to 10 (m 3 tonne -1 ), producing an effluent high in chemical oxygen demand (COD) load, which is discharged to the sea. Alternative treatments were studied from economic and environmental aspects. The selected treatment involved two sequential steps : recycling of water during unloading and salvaging of reusable organic matter by chemical coagulation of soluble proteins with FeCl 3 followed by centrifugal separation. The recovered sludge was incorporated into the fish-meal process. Technical feasibility and cost implementation at industrial-scale were assessed. Results obtained at one plant demonstrated overall COD removal efficiencies of 93% for the clarified effluent (91% for proteins and 93% for fats and oil). Incorporation of the precipitated organic matter into the process increased productivity by approximately 7%.

Aromatic hydrocarbons on surface waters of Admiralty Bay, King George Island, Antarctica

Total aromatic hydrocarbons were measured for surface seawater at 24 points in Admiralty Bay, Antarctica, during the summers of 1989, 1990, 1992 and 1993, using the spectrofluorimetric method. The levels varied between 0.05 and 8.86 μg l −1, but the majority of the samples presented levels below 1.00 μg l −1, so there were no alarming oil inputs in the area. In 1992, one point in front of the Antarctica Station Comandante Ferraz was sampled with an automatic pre-concentration unit capable of processing large volumes of seawater for GC-MS analysis. This water sample presented a total aromatic content of 0.080 μg l −1. Main two-ring aromatic compounds quantified by GC-MS were naphthalene, acenaphthylene, 1-methylnaphthalene, 2-methylnaphthalene and acenaphthene. Of the three-ring polycyclic aromatic hydrocarbons (PAHs), phenanthrene contributes more than anthracene. Of the four-ring members, fluoranthene is more abundant than pyrene. Five-ring or six-ring members were not found. These individual levels and types of PAHs are typical of marine environments with small oil-derived hydrocarbons inputs.

A NEW, ARTIFICIAL SEA WATER THAT FACILITATES GROWTH OF LARGE NUMBERS OF CELLS OF ACETABULARIA ACETABULUM (CHLOROPHYTA) AND REDUCES THE LABOR INHERENT IN CELL CULTURE1

ABSTRACTWe designed a new, artificial seawater (Ace 25) in order to grow bulk cultures of Acetabularia acetabulum (L.) Silva with a minimum of labor. To this end, we modified the traditional recipe for cell growth (Müller's medium as modified by Schweiger et al.) We eliminated five of the inorganic chemicals and determined the optimum concentration for 16 of the remaining 18 inorganic chemicals from modified Müller's seawater. Ace 25 enables growth of A. acetabulum from the beginning of the juvenile phase through gametangial formation in 11 weeks at high cell densities without medium replenishment. This represents a 98% reduction in the seawater volume required to mature each cell, a 30–40% reduction of the duration of the life cycle, an estimated 80% reduction in labor, and a 50–95% reduction in the space required for culturing A. acetabulum as compared with traditional procedures. These improvements may facilitate studies that require large numbers of cells such as population studies, genetics, and biochemistry, contribute to understanding the nutritional requirements of marine algae, and extend the use of this cell to those who lack the space or manpower to grow the cells in the traditional manner.

Octopus vulgaris (Mollusca, Cephalopoda) as a model in behavioral pharmacology: A test of handling effects

Despite the great interest of Cephalopods in learning studies, behavioral pharmacological experiments using these animals are scanty. The purpose of this study was to find an appropriate method of injection of substances for studying their effects on the behavior of octopuses. We injected into the branchial heart a known volume of seawater to test the effect of cold anaesthesia and of different types of manipulation on the predatory performance of Octopus vulgaris. An injection procedure that is simple, reliable, and does not require anaesthesia is proposed. The article also addresses ethical and manipulation requirements of modern behavioral pharmacology.

Rapid visualization of plankton abundance and taxonomic composition using the Video Plankton Recorder

Traditional methods for determining spatial distributions of planktonic taxa involve net, pump, and bottle collections followed by the tedious and time-consuming task of plankton sample analysis. Thus, plankton ecologists often require months or even years to process samples from a single study. In this paper, we present a method that allows rapid visualization of the distribution of planktonic taxa while at sea. Rapid characterization of plankton distributions is essential in the dynamic physical environment, where biological and physical patterns can change quickly. Such a “sample-and-observe” capability is necessary for mapping ephemeral features (such as patches, eddies, jets, plumes) and determining appropriate locations to conduct more localized sampling, including in situ observational studies. We describe the techniques used in imaging the plankton, analyzing the video, and visualizing the data. We present an example of at-sea data analysis conducted aboard R.V. Columbus Iselin on Georges Bank in May 1994 and visualizations of the 3-dimensional distribution of selected planktonic taxa in a 2 × 2 km × 90 m volume of seawater.

循環式泡沫分離‐ろ過システムによるヒラメ畜養水の浄化

When one thousand individual Japanese flouns Paralichthys olivaceus of about 900g each were introduced into the closed foam separation-filtration system, changes with the passage of time in the quality of fish rearing seawater (15.5°C) and foam wastewater were examined. The foam separation-filtration system consisted of a fish rearing tank (seawater volume 10m3), two circulation pumps, two foam separating units equipped with air-inhale-discharge type aerator and a filter. The quality of fish rearing seawater was kept clean for several months without any works such as washing filter and changing fish rearing seawater to maintain seawater quality for the living fish. During the 18 hours after the fish were received in the fish rearing tank, the quality of the fish rearing seawater was kept at an average of pH, 7.5; DO, 101%; Turbidity, 0.22 FTU; SS, 0.32mg/l; DOC, 3.17mg/l; NH4-N. 0.80mg/l, N03-N, 47.2mg/l; total viable bacteria, 2.1×104 CFU/ml; and Vibrios, 1.2×103 CFU/ml. Foam generation volume was 30l/day. The foam separation-filtration system was very useful for removing pollutants from fish rearing seawater.

Determination of99Tc in coastal seawater collected in Fukuoka, Japan

(ICP-MS) on coastal seawater in the general environment in Japan. Technetium was enriched on iron hydroxide by repetitive co-precipitation method from a large volume of seawater and separated from impurities by solvent extraction and ion-exchange techniques. The concentrations of 99Tc were 1.0 to 7.4 /A3ql ~, which was one order of magnitude lower than the level reported on seawater from general environment by beta-ray counting. Concentrations of ~37Cs determined on the same seawater were 3.7 and 3.9 mBql 1. The activity ratio of 9~I'c]~TCs was calculated to be 2,7x10 "4. This ratio was very close to the value expected for fallout from nuclear tests.

Frontomandibular Stay of Balaenopteridae: A Mechanism for Momentum Recapture during Feeding

The feeding process of Balaenopteridae (rorquals) is characterized by an energetic event in which a large volume of seawater is engulfed and filtered. Here we identify a major structural component of a stay apparatus that exists in the rorqual craniomandibular system. This fibrous appendage of the temporalis muscle introduces a continuous, mechanical linkage between the supraorbital process of the frontal bone and the coronoid process of the mandible. It is named the frontomandibular stay. Anatomic relationships and biomechanical findings predict that this structure would control and assist a process of continuous change in position of the jaws during engulfment events. The dynamic form of mandibular kinesis produced would function to increase the power of feeding. Owing to the stay's nonmuscular construction, its mechanical action necessarily is driven by the kinetic mass of the moving whale.

Combined sewer overflow control using storage in seawater

This paper describes the flow balance method facility (FBM) used to control a combined sewer overflow (CSO) and a statistically based efficiency evaluation for the system. The FBM uses containment within a receiving water body (in this case seawater) to store CSO followed by pumpback to the wastewater treatment plant for treatment. The efficiency evaluation uses a mass balance incorporating measured specific conductivity and flow volumes with their probability distributions in a Monte Carlo model to calculate probable volumes of seawater in the pumpback and hence efficiency of the system. The methods described in the paper refer to phase 1 and form the basis for monitoring phase 2 of the project. Important aspects of this analysis for phase 2 of the FBM demonstration included: confirmation of the reliability of specific conductivity to determine the volume of seawater in the pumpback; an indication of the sensitivity of the predicted efficiency to variation in the parameters used; and therefore, identification of the relative importance of the different data distributions to allow more effective data collection in phase 2.

Bioluminescent organisms and bioluminescence measurements in the North Atlantic Ocean near latitude 59.5°N, longitude 21°W

We investigated mixed‐layer bioluminescence from early April to late September (in April 1989, May 1991, July 1983 and 1990, August 1991, September 1988 and 1989) at stations near the Marine‐Light ‐ Mixed Layers (MLML) bio‐optical moorings site. Volume‐specific bioluminescence potential (BPOT, photons per unit volume) from epipelagic organisms was estimated directly with a pump‐through bioluminescence photometer (BP) in 1983, 1988, and 1991. For all cruises, BPOT was also estimated by summing for a volume of seawater, the measurements of each species′ total stimulable bioluminescence multiplied by each species′ numerical abundance in the volume. The abundance data were taken from bottle casts, net tows, and BP effluent nets. After the onset of the spring bloom, from May through September, mixed layer BPOT was fairly constant, ∼1–4×1014 photons m−3. On one early April cruise (1989) before the spring bloom, BPOT was two orders of magnitude lower. Heterotrophic dinoflagellates in the genus Protoperidinium generally produced most (90% or more) of the mixed layer BPOT in the spring, summer, and fall. On one cruise in September (1988), the autotrophic dinoflagellate Ceratium fusus produced the bulk of the mixed layer BPOT (more than about 4×1014 photons m−3). Other autotrophic dinoflagellates in the genus Gonyaulax and mesozooplankton produced a minor part of BPOT at most stations. The relative contribution of all autotrophic dinoflagellates to BPOT increased from a few percent during the May–June–July period to ∼10% during the August–September period. In situ mechanically stimulable bioluminescence was reduced when underwater scalar irradiance (wavelengths 400–700 nm) was greater than 0.1 μmol photons m−2 s−1.

A Study of Factors Influencing the Hatch Rate of Penaeus vannamei Eggs. I. Effects of Size, Shape and Volume of the Spawning Tank

The hatch rate of Penaeus vannamei eggs spawned by individual females in square and round tanks and in different volumes of seawater was determined. The mean hatch rates ranged from 17.3% to 64.9% and were not significantly different for volumes of 50, 100 and 200 L nor for square or round tanks of equal water volumes. Hatch rate was significantly affected by the size of the spawning tank.

Symbiotic Role of the Viable but Nonculturable State of Vibrio fischeri in Hawaiian Coastal Seawater

To achieve functional bioluminescence, the developing light organ of newly hatched juveniles of the Hawaiian squid Euprymna scolopes must become colonized by luminous, symbiosis-competent Vibrio fischeri present in the ambient seawater. This benign infection occurs rapidly in animals placed in seawater from the host's natural habitat. Therefore, it was surprising that colony hybridization studies with a V. fischeri-specific luxA gene probe indicated the presence of only about 2 CFU of V. fischeri per ml of this infective seawater. To examine this paradox, we estimated the total concentration of V. fischeri cells present in seawater from the host's habitat in two additional ways. In the first approach, the total bacterial assemblage in samples of seawater was collected on polycarbonate membrane filters and used as a source of both a crude cell lysate and purified DNA. These preparations were then assayed by quantitative DNA-DNA hybridization with the luxA gene probe. The results suggested the presence of between 200 and 400 cells of V. fischeri per ml of natural seawater, a concentration more than 100 times that revealed by colony hybridization. In the second approach, we amplified V. fischeri-specific luxA sequences from microliter volumes of natural seawater by PCR. Most-probable-number analyses of the frequency of positive PCR results from cell lysates in these small volumes gave an estimate of the concentration of V. fischeri luxA gene targets of between 130 and 1,680 copies per ml. From these measurements, we conclude that in their natural seawater environment, the majority of V. fischeri cells become nonculturable while remaining viable and symbiotically infective. Experimental studies indicated that V. fischeri cells suspended in natural Hawaiian seawater enter such a state within a few days.

Biotransformation of genotoxic agents in marine sponges. Mechanisms and modulation

Marine sponges do not appear to suffer from neoplastic diseases, in spite of possible high exposures resulting from their nature as sessile bottom filter feeders which pump large volumes of sea water. The assessment of several parameters related to the biotransformation of mutagens/carcinogens showed that the metabolic machinery of sponge medulla cells is mainly oriented towards detoxification, with some differences depending on species (Geodia cydonium or Tethya aurantium). Glutathione (GSH) levels were unexpectedly high in these cells, especially in Geodia, in which the concentration of this tripeptide was more than twice that measured in liver preparations from untreated rats, at least when related to the protein content. The oxidoreductive enzyme activities involved in the glutathione cycle were balanced in such a way as to favour a high GSH: oxidized glutathione (GSSG) ratio. GSH S-transferase activity was conversely rather low, compared to that of rat liver, and the dehydrogenases involved in the hexose monophosphate shunt were high in Tethya but low in Geodia. The metabolism of mutagens was investigated by using the Salmonella typhimurium his- strains TA100, TA98 and YG1024. Sponge S12 fractions failed to activate aflatoxin B1, benzo[a]pyrene and the two heterocyclic amines 3-amino-1-methyl-5H-pyrido[4,3-b]indole and 2-amino-3,4-dimethyl-imidazo[4,5-f]quinoline. Although far less efficiently than untreated rat liver S12 fractions, Geodia and especially Tethya preparations weakly activated the three aromatic amines 2-acetyl-aminofluorene, 2-aminofluorene and 2-aminoanthracene. On the other hand, sponge S12 fractions were remarkably efficient in decreasing the mutagenic potency of the direct-acting mutagens 4-nitroquinoline 1-oxide and sodium dichromate.(ABSTRACT TRUNCATED AT 250 WORDS)

Preconcentration of Indium(III) by Coprecipitation with Gallium Phosphate for Electrothermal Atomization Atomic Absorption Spectrometry

Abstract Gallium phosphate coprecipitates quantitatively 0.5—7.5 μg of indium(III) from 100—500 cm3 of water at pH 2.5—6.0 and from the same volume of sea water at pH 3.5—6.0. The detection limit (signal/noise = 2) is 0.3 ng cm−3 of indium(III) in 500 cm3 of the initial sample solution.