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Distribution of brackish-water zooplankton was surveyed in the Chikugo River estuary, Japan, at 3-h intervals for 24 h, including several hours when the river was heavily flooded because of rainfall and discharge from an upstream dam. The populations of the dominant copepodsPseudodiaptomus inopinusandSinocalanus sinensiswere concentrated in the mixing zone of the salt wedge before river flooding. During the period of flooding, they were almost completely swept out from the river, but examination of water trapped by a sediment grab sampler revealed that adults ofPseudodiaptomus inopinuswere aggregated immediately above the bottom of the submerged channel outside the river mouth. After the flood, aggregations of both species appeared again in the river together with the salt wedge, and the proportion of adults in the aggregations became significantly higher than before. These results suggest that immature copepods suffer population losses through river flooding, but that the copepods can survive such flooding by means of both behavioral and reproductive mechanisms; that is, adult copepods maintain their position on the bottom of submerged channels outside the river mouth during a river flood and replace the population loss through reproduction after the flood. Channels outside river mouths are thus regarded as important topographic refuges for river-estuarine zooplankton to survive a flood. [ABSTRACT FROM AUTHOR]

Diatoms in surface sediments from a data set of 27 brackish lakes and nine fjords in Jutland, Denmark (range 0.2 – 31 g·L–1 total dissolved solids (TDS)), were analysed using multivariate methods to determine response to measured parameters (depth, total phosphorus (TP), total nitrogen (TN), TN/TP, salinity, water body type). Water body type, salinity, depth and TP together explained 25.3% of the variation in the diatom data and were all independently significant predictors. A diatom–salinity model (r2jack = 0.887, root mean square error of prediction = 0.246 log salinity, g·L–1) was developed from the 36 sample training set and applied to fossil diatom assemblages in three sediment cores from the east Vejlerne wetland, Denmark, a nature reserve created after the damming of an embayment of the polyhaline Limfjord (~26 g·L–1 TDS) in the late 19th century. The diatom–inferred salinity reconstructions reflect the known salinity history of the Limfjord and the freshwater–subsaline Vejlerne lakes, and appear sensitive to documented North Sea storms in the 16th and 17th centuries, which had major impacts on the brackish Limfjord herring fishery. Diatom–salinity models may be useful tools in long-term studies of coastal and estuarine areas to test hypotheses concerning aquatic resources and ecological, hydrographic, and cultural change. [ABSTRACT FROM AUTHOR]

Rangia and marsh clams, Rangia cuneata, R. flexuosa, and Polymesoda caroliniana, occur in brackish waters along Mexico's eastern coast from the northern State of Tamaulipas to the southern State of Campeche. The clams were important to the prehispanic people in the southern pan of the State of Veracruz, where they were used as food and as construction material. In modern times, they are harvested for food The fishermen wade in shallow water and harvest the clams in soft sediments by hand. Annual landings of whole clams during a recent 5-yr period, 1998-2002, were 1,139-1,695 t. The only area with a substantial ongoing clam fishery is in the Lower Papaloapan River Basin, including Alvarado Lagoon, where as many as 450 fishermen are licensed harvesters. This fishery for the Rangia and marsh clams is the most important clam fishery along Mexico's Gulf Coast. [ABSTRACT FROM AUTHOR]

The Orion 94-29 Cu(II) jalpaite ion selective electrode (Cu-ISE) was used to measure both the concentration of the aqueous free Cu(II) ion ([Cu(II)aq]) and its changes due to additions of Cu, in artificial seawater (ASW) and in seawater from San Diego Bay, CA. The range of free copper ion (i.e., pCu, -log [Cu(II)aq]) determined in seawater samples from the San Diego Bay area (11.3-12.6, 11.9 ± 0.4, average ± SD) is consistent with that previously reported for estuarine and coastal areas (10.9-14.1). The changes in [Cu(II)aq] as a result of the additions of Cu were used to determine the Cu complexation capacity (Cu-CC), which has a measured range (2.7 × 10-8-2.0 × 10-7 M; 7.6 × 10-8 ± 4.8 × 10-8 M) comparable to the range of values previously reported for estuarine and coastal zones (i.e., L1+L2, 1.1 × 10-8-2.0 × 10-7 M). The narrow range of pCu at the Cu-CC (pCucu-cc, 11.1-11.9, 11.5 ± 0.2) indicates the predominant role of the Cu-CC in regulating the concentration of ambient Cu(II)aq to a level ≤ 1 × 10-11 M Cu-(II) aq. These results attest to the capability of the Cu-ISE to measure pCu and Cu-CC in aquatic coastal environments with relatively high total Cu concentrations and organic loads, such as those from heavily used coasts and bays. [ABSTRACT FROM AUTHOR]

Increasingly, management agencies require that the remediation of eutrophic waters be addressed at the level of the whole ecosystem. One whole-system approach to quantify ecosystems is called ecological network analysis. Ascendency theory, the branch of the field that deals with the quantification of whole-system status, specifically addresses the definition of eutrophication. This definition has been applied to data taken over a gradient of eutrophication. Three separate areas were observed: a non-eutrophic area (with Zostera noltii meadows), an intermediate eutrophic area (Z. noltii absent and macroalgae abundant at times) and a strongly eutrophic area (where Enteromorpha spp. blooms occur with regularity). Pulse eutrophication was considered as the major driving force behind a gradual shift in primary producers from a community dominated by rooted macrophytes (Z. noltii) to a community dominated by green macroalgae. The measures associated with the intermediate eutrophic region turned out not to be intermediate to those at the gradient extremes. The most likely explanation appears to be the highly unstable nature of this area. Conditions along the spatial gradient are discussed as representing various stages in the temporal evolution of the system, and analysed in the framework of the Intermediate Disturbance Hypothesis, Bifurcation, Chaos, and Catastrophe theories. [Copyright &y& Elsevier]

Here we present results of a 1-year realistic North Sea simulation from the new model GETM (general estuarine transport model) and assess the capabilities of this model by comparing them to model results from the well-known HAMSOM (Hamburg shelf sea and ocean model) model, in situ data from the North Sea project and satellite-derived sea-surface temperature data. The annual cycle and the spatial variability of stratification and mixing in the North Sea is simulated. It is shown that the new model is successful in reproducing the general temporal and spatial dynamics of the North Sea. The major advantages of GETM for achieving improved results in this simulation are the implementation of general vertical coordinates, of a state-of-the-art turbulence model and of higher-order advection schemes. By exploiting the full capabilities of these features a more realistic simulation could be achieved. We found that the greatest differences in the model results are produced by applying advection schemes of different complexity. Here we are able to demonstrate that better advection schemes lead to stronger horizontal gradients and stronger vertical stratification during summer. When comparing these results to measurements from the North Sea project and to satellite data, we find that these stronger gradients are more realistic. Therefore, we consider it as essential to use such high-order advection schemes if the spatial variability of estuarine or shelf seas like the North Sea is to be resolved adequately. The advanced turbulence closure scheme also contributed to more realistic simulation of the vertical stratification. Finally, general vertical coordinates better resolve the shallow regions, but are also useful for the deeper regions, as they allow a better estimation of sea-surface temperature compared to traditional σ coordinates. [ABSTRACT FROM AUTHOR]

A new numerical model for simulating estuarine dynamics is introduced here. This model, called General Estuarine Transport Model (GETM), has been specifically designed for reproducing baroclinic, bathymetry-guided flows where the tidal range may exceed the mean water depth in large parts of the domain such that drying and flooding processes are relevant. Several physical and numerical features of the model support exact and stable results for such domains. For the physics, high-order turbulence closure schemes guarantee proper reproduction of vertical exchange processes. Among the specific numerical features, generalised vertical coordinates, orthogonal curvilinear horizontal coordinates, high-order TVD advection schemes and stable drying and flooding algorithms have been implemented into GETM. The model is applied here to simulate the dynamics of estuarine turbidity maxima (ETMs), a complex feature present in most tidal estuaries. First, idealised simulations for a two-dimensional domain in the xz space will be shown to reproduce the basic generation mechanisms for ETMs. Then, a realistic three-dimensional simulation of the Elbe estuary in Northern Germany will be carried out. It is demonstrated that for a given forcing situation the model reproduces a stable ETM at the correct location. [ABSTRACT FROM AUTHOR]

Natural variability in the myriad of physical processes that impact and control estuaries occurs at time scales that typically may exceed or partly exceed many monitoring programs. With respect to documenting and monitoring impacts of human influences­ on estuaries, it is therefore important to frame the results of short-term monitoring programs within the context of longer term natural variability in the environment. In the Tampa Bay, Florida area, climate variability strongly influences seasonal precipitation, stream flow, and salinity. In particular, El Niño-Southern Oscillation impacts during the winter have the potential to influence both the availability of surface water for water supply withdrawal and the evaluation of the impacts of surface water withdrawals on the ecosystem. [ABSTRACT FROM AUTHOR]

Focuses on the several species of gobioid fishes found in the waters of North Carolina. Collection of specimens using variety of methods; Number of species restricted to a variety of shallow estuarine habitats; Presentation of the distribution and habitat data of the species;

This study describes a hyporheic zone that exists beneath a river-dominated estuary in North Wales, and which spans the freshwater/saltwater boundary. A series of 72 cores was taken from the Aber Estuary, in September, at depths from 10–60 cm below the bed surface. Site 1 was above the extreme high water mark and therefore was never inundated by salt water. Site 5 was the furthest downstream and was inundated twice daily by incoming tides. Substrates contained more gravel at the upstream sites and closer to the bed surface, with more sand and silt at downstream sites and at depth. Salinity of interstitial water increased both with distance away from Site 1 and with increasing depth into the zone, reaching a maximum of 15‰ at 60 cm at Site 5, as measured at low tide. Longitudinal and vertical zonations of the invertebrate taxa were evident, and densities were greater in the top 40 cm than below. Nematodes were especially abundant from 10–60 cm, and genera differed along the estuary. Oligochaetes were well represented at most sites, with the less saline sites yielding Naididae, Enchytraeidae, Aeolosomatidae and Tubificidae; Site 5 was dominated by Tubifex costatus. Chironomid larvae were most abundant to 40 cm at Sites 1 and 2 (primarily Brillia modesta, Corynoneura sp., Tanytarsus sp., and unidentified Tanypodinae), but they were also found at Site 3 (to 60 cm), and at 10 cm at Site 5 (Orthocladius sp.). Nymphs of mayflies and caddisfly larvae were found primarily at Site 1, but small stonefly nymphs and elmid beetle larvae were taken at Site 2 depths where the interstitial water was brackish. The most saline sediments were populated by the triclad Uteriporus vulgaris, the polychaete Nereis sp., and snails (Hydrobia sp.). Site, salinity, pH, and sand and silt contents appeared to influence species distribution most; together, these explained 37.8% of the variance (CANOCO). There was an overall negative relationship between silt content of the sediments and total invertebrate density. The hyporheic zone of the Aber Estuary is thus not only influenced by surface water and, presumably, estuarine groundwater exchanges, but is further complicated, biologically, by having a salinity gradient running through it. The term `brackishwater hyporheic zone' (BHZ) is proposed to describe this and similar systems. [ABSTRACT FROM AUTHOR]

Abstract: Presented are results of morphological (LM and SEM) and taxonomical investigations on very small-sized Navicula spp. from the brackish waters of the Gulf of Gdansk and some freshwater affluents. Detailed studies revealed that most of the taxa in question are either new for science or previously described but rather poorly known. Dominant in that assemblage of extraordinarily small-celled Navicula species, specimens mostly below 10 μm in length, are Navicula germanopolonica Witkowski & Lange-Bertalot and Navicula paulschulzii Witkowski & Lange-Bertalot as established taxa. New for science are Navicula aleksandrae, Navicula bozenae and Navicula viminoides ssp. cosmomarina. From common freshwater habitats no species are known that could be confused with the new taxa. [Copyright &y& Elsevier]

In order to study micro-spatial distribution of amoebae, an intact slice of sandy sediment from the brackish-water Nivå Bay (Baltic Sea, The Sound), 40 × 24 mm in size and 2 mm in thickness was gently sectioned into cubes, 2 × 2 × 2 mm in size. Each cube was inoculated into enrichment media to reveal the biodiversity of amoebae. Seventeen species of amoebae were recovered. The 2-D map of amoebae species distribution in the slice, consisting of 240 2 × 2 mm cells was drawn and analyzed. Results show heterogeneous distribution of amoebae at the scale of centimeters and millimeters and confirm the idea of the presence of microhabitats, selectively occupied by amoebae species. Three types of distribution patterns were found: random, aggregated and equally spaced. Microelectrode studies indicated that amoebae distribution was not related to the dissolved oxygen content in the sediment. The studied slice of sediment contained several pronounced "hotspots" of amoebae biodiversity, where up to four species co-occur in the same area. Seven species of amoebae numbered 1-4 specimens in the studied slice (i.e. there was 0.5-2 cell ml-1). Analysis of the amoebae distribution map shows the high probability of undersampling rare amoebae species during faunistic studies. [ABSTRACT FROM AUTHOR]

Presents a study which proposed a mathematical model to stimulate brackish karstic springs. Characteristics of karstic spring; Hydrodynamic model of brackish karstic springs; Application of the model to stimulate the Almiros spring.

Biological responses and contaminant levels in biological tissues were investigated in fish specimens of grass goby (Zosterisessor ophiocephalus) collected in spring 2000 in a moderately polluted brackish ecosystem, the Orbetello lagoon (southern coast of Tuscany, Italy). The complexity of harmful effects that contaminants may cause in fish over time was assessed. General condition indices (somatic liver index, and gonadal somatic index), cytochrome P450 enzymes, acetylcholinesterase activity and ovarian morphology were integrated with the content of organochlorines (OCs—hexachlorobenzene, DDTs and polychlorinated biphenyls) in liver and ovaries and p-nonylphenol (NP) and lower ethoxylate (NPE1–2) content in muscle and ovaries as well. Samples collected from the western basin of the lagoon near the Orbetello sewage treatment plant had somatic liver index values and two P450 activities significantly higher than those collected from the same basin at the Albegna river delta and in the Ansedonia canal in the eastern basin (P < 0.05). On the other hand, while muscle content of p-NP and NPE1–2 was significantly higher in samples from the Orbetello and Albegna river sites than in samples from the Ansedonia canal site, OC levels in liver (DDTs > PCBs > HCB) were particularly lower in samples from STP compared to levels detected in sites AC and AR. Light microscopy of ovaries revealed that although the gonads were sexually mature, the diameter of the oocytes and eggs was smaller than that commonly reported. High levels of OCs and NPs were, in fact, observed in grass goby ovaries, and the differences observed between acetylcholinesterase activities among investigated sites suggest exposure to insecticides as well. The integration of biological responses and contaminant tissue content reveals that certain areas of the lagoon are selectively impacted by various human activities and helps in distinguishing relationships between biological responses and contaminant load in the lagoon environment. [Copyright &y& Elsevier]

Presents the results of an effort to monitor a population of Enochrus bicolor (Fabricius) over a 4-year period (March 1997-March 2001) from a coastal brackish pool in S.E. Essex. This water beetle, together with Ochthebius marinus (Payk.), O. viridis Peyrhiff, O. punctatus Steph., Hygrotus parallelogrammus (Ahrens), Berosus affinis Brulle, Agabus conspersus, (Marsham), Rhantus frontalis (Marsham), R. suturalis (MacLeay), Paracymus aeneus (Germar), and Haliplus apicalis Thompson, are all taxa of conservation interest. Enochrus bicolor was present in most months, with greatest adult abundances being recorded in August and September each year. Correlation analysis and the development of regression models indicated that the highest abundances of E. bicolor coincided with maximum water temperature in the late summer-early autumn. However, when the natural seasonal signal was removed by standardizing the series, a relatively weak association with the relative abundance of E. bicolor and conductivity was observed. The conservation of E. bicolor and other organisms associated with brackish water habitats subject to irregular marine inundation is considered.

Focuses on a population of Enochrus bicolor (Fabricius) that was monitored over a four-year period (March 1997-March 2001) from a coastal brackish pool in S.E. Essex. Other aquatic organisms of conservation interest to researchers; Months in which Enochrus bicolor was present; Salinity values during the study period; Correlation analysis and the development of regression models indicating that the highest abundances of E. bicolor coincided with maximum water temperature in the late summer-early autumn; Suggestion that when the natural seasonal signal was removed by standardizing the series, a relatively weak association with the relative abundance of E. bicolor and conductivity was observed; Consideration of the conservation of E. bicolor and other organisms associated with brackish water habitats subject to irregular marine inundation.

Holocene stratigraphy is established from 3.5-kHz seismic reflection data and a number of vibro cores across the narrow Fehmarn Belt between Germany and Denmark. Using detailed line drawings, texture, seismic and lithofacies analyses in a selected part of the study area, a distinct depositional unit 5 was identified. The unit was subdivided into sub-units 5a to 5j due to a different seismic texture and facies pattern. The base of the unit 5 is generally smooth but with step-like parts which are interpreted to result from tectonism. In each sub-unit the seismic facies association includes mound, oblique seismic facies and within channel deposits sigmoid, shingled and parallel facies. The sub-unit represents offset stacked lagoonal and spit deposits deposited under conditions of progressive sea-level rise. Sub-units 5a to 5h show a change in depositional style from fluvial domination to gradually more wave-influenced. Thus, the dynamic evolution of the shallow marine sub-sea-floor environment and changes in depositional conditions are revealed by high-resolution seismic facies associations. [Copyright &y& Elsevier]

Abstract Aboveground biomass, macro-organic matter (MOM), and wetland soil characteristics were measured periodically between 1983 and 1998 in a created brackish-water marsh and a nearby natural marsh along the Pamlico River estuary, North Carolina to evaluate the development of wetland vegetation and soil dependent functions after marsh creation. Development of aboveground biomass and MOM was dependent on elevation and frequency of tidal inundation. Aboveground biomass of Spartina alterniflora , which occupied low elevations along tidal creeks and was inundated frequently, developed to levels similar to the natural marsh (750 to 1,300 g/m2 ) within three years after creation. Spartina cynosuroides , which dominated interior areas of the marsh and was flooded less frequently, required 9 years to consistently achieve aboveground biomass equivalent to the natural marsh (600 to 1,560 g/m2 ). Aboveground biomass of Spartina patens , which was planted at the highest elevations along the terrestrial margin and seldom flooded, never consistently developed aboveground biomass comparable with the natural marsh during the 15 years after marsh creation. MOM (0 to 10 cm) generally developed at the same rate as aboveground biomass. Between 1988 and 1998, soil bulk density decreased and porosity and organic C and N pools increased in the created marsh. Like vegetation, wetland soil development proceeded faster in response to increased inundation, especially in the streamside zone dominated by S. alterniflora. We estimated that in the streamside and interior zones, an additional 30 years (nitrogen) to 90 years (organic C, porosity) are needed for the upper 30 cm of created marsh soil to become equivalent to the natural marsh. Wetland soil characteristics of the S. patens community along upland fringe will take longer to develop, more than 200 years. Development of the benthic invertebrate-based food web, which depends on organic matter enrichment of the... [ABSTRACT FROM AUTHOR]

The activities of naturally occurring radium isotopes (226Ra and 228Ra) in estuarine water were measured downstream of the dam constructed in the Nakdong River, Korea. The sampling of surface waters for radium, silicate, and suspended solid (SS) analyses was conducted at 18 stations during three periods (July 1997, April 1998, and June 1999). In general, radium activities exceeded the value expected from the mixing of two freshwater and seawater endmembers. We characterized the responses of Ra and Si according to three different conditions: (1) when the freshwater discharge and the water level of the dam relative to the sea level at low tide were lower (April 1998), the excess Ra and Si contents were lower in the estuary; (2) when the fresh water discharge was larger following heavy precipitation (July 1997), both excess Ra and Si contents were higher in the estuary with conservative mixing of Si; and (3) when the water level of the dam relative to the sea level at low tide was highest under low freshwater discharge (June 1999), high excess Ra but low Si levels were observed. The occurrence of high Ra activity in June 1999 was likely due to the large submarine brackish groundwater discharge downstream of the estuary. Since brackish groundwater in general contains high concentrations of nutrients, Ba, Ra, etc, our result suggests an important role for the submarine groundwater discharge on the biogeochemistry of estuarine/coastal waters, especially when the water level of the dam (hydraulic head) is high. [Copyright &y& Elsevier]

Provides information on a study that examined the structural characteristics of zoobenthos and zooperiphyton communities, the floristic composition and phytocenotic structure of aquatic vegetation and peculiarities of the plant cover in various water bodies of the estuarine region of the Vita River. Methodology of the study; Results and discussion on the study; Conclusion.

Focuses on preliminary results of biomarker responses in zooplankton of brackish environments. Significance of zooplankton in food chains of marine and brackish environments; Signal of risk to the health of marine ecosystems; Higher metabolic rates in the species.

Total Hg contents from abiotic (surface sediments and suspended particulate matter) and biological (crabs, fishes and halophytes) compartments from Bahía Blanca estuary and Mar Chiquita Coastal Lagoon, Argentina, have been monitored since the 1980's. At Bahía Blanca estuary, high Hg concentrations were recorded during the early 1980's in surface sediments (0.34 ± 0.22 μg/g) and suspended particulate matter (0.19 ± 0.10 μg/g). Fish species, Mustelus schmitti (0.89 ± 0.29 μg/g), Paralichthys brasiliensis (0.85 ± 0.18 μg/g) and Micropogonias furnieri (0.37 ± 0.11 μg/g) also presented high Hg concentrations. The large industrial nucleus located within the estuary has been identified as the main metal source for this environment. Hg contents from the same area during 1996–1998 were significantly lower: surface sediments (0.164 ± 0.023 μg/g), suspended particulate matter (0.048 ± 0.0017 μg/g), fish Micropogonias furnieri (0.13 ± 0.02 μg/g) and crab Chasmagnathus granulata (0.334 ± 0.071 μg/g). This trend of environmental detoxification is probably related with (i) the technological changes incorporated by the local industry, (ii) a most adequate management of industrial effluents, and (iii) the removal of great sediment volume by dredging and refill. During the 1980's Mar Chiquita Lagoon Hg concentrations reached 0.08 ± 0.01 μg/g in surface sediments and 0.09 ± 0.025 μg/g in suspended particulate matter, and 0.14 ± 0.04 μg/g in the fish Basilichthys bonariensis and 0.22 ± 0.08 μg/g in Paralichthys brasiliensis, and 0.08 ± 0.01 μg/g in the crab C. granulata, Hg concentrations were lower than at Bahía Blanca. Remote Hg sources for this Coastal Lagoon and atmospheric and stream transport of Hg is proposed as major Hg sources, since no Hg point sources exists nearby. Mercury concentrations recorded in the 1996–1998 period were lower than those recorded in the previous decade: surface sediments (0.019 ± 0.004 μg/g), suspended particulate matter (0.030 ± 0.008 μg/g), halophyte Spartina densiflora (0.013 ± 0.008 μg/g) or crab C. granulata (0.011 ± 0.009 μg/g). Both Hg bioaccumulation and biomagnification processes were verified in Bahía Blanca estuary and in Mar Chiquita Coastal Lagoon. This apparent recovery of both estuarine environments deserves to be carefully analyzed, in order to fully understand the foundations of these processes. [ABSTRACT FROM AUTHOR]

A new methanogen, designated as strain P2F9701a (= OCM 745), was isolated from a water sample of estuarine environment in Elrin Shi, Taiwan. Cells of strain P2F9701a were motile coccus (0.7∼1.1 μm) with tufts of flagella. Gas vacuoles were observed, and the protein cell wall was composed of S-layer protein subunit with Mr of 74,700. Cells catabolized formate and H2+CO2 to produce methane, but not acetate, methanol, and trimethylamine. Strain P2F9701a grew in the range of 30–42°C, with optimal growth temperature at 37°C, but did not grow below 28°C or above 42°C. This estuarine isolate P2F9701a tolerated well the NaCl concentration between 0.02 and 1.03 m, and the optimal salt for growth was 0.17 m. Although phylogenetic analytic results indicated that P2F9701a belongs to the mesophilic, hydrogenotrophic marine methanogen of Methanococcus voltaei, the occurrence of gas vacuoles, tufts of flagella, eury-halotolerant and steno-thermotolerant characters of strain P2F9701a are different from mesophilic Methanococcus spp. that had been reported. [ABSTRACT FROM AUTHOR]

To improve the indicator value of marginal marine Foraminifera and Ostracoda of Ghana, we analysed 22 surface sediment samples for microfauna. They were obtained from the Keta Lagoon and Densu Estuary covering a salinity range from marine waters to 17.5 and one sample within the hyperhaline range (70). Except one, all samples contain Ostracoda and Foraminifera. There are 34 ostracod species belonging to 24 genera. Dominating is Cyprideis remanei Klie, 1940, other abundant species are Pseudoconcha sp., Pseudoconcha hartmanni Omatsola, 1970 , Loxoconcha lacunensis Omatsola, 1970 and Chrysocythere foveostriata Brady, 1870. We found 28 Foraminifera species belonging to 22 genera with the dominant taxa Ammonia sp. and Quinqueloculina spp. There are five associations, which are mainly driven by the hydrological regime and organic pollution. In contrast to a usual diversity trend reflecting high levels of pollution by lower diversity, our results show higher diversity associated with sites of higher pollution levels. The most tolerant (salinity and pollution) ostracod taxon is Cyprideis remanei , which is occurring over the whole salinity range documented as well as in contaminated areas with very high LOI and heavy metal concentrations. In the investigated samples we found many deformed Foraminifera with anomalies like multiple tests, changes in coiling and aberrant shapes of the chambers. Ongoing investigations in estuaries of Ghana are expanding our data set and will provide a better understanding of species-specific reactions of Ostracoda and Foraminifera to anthropogenic pressure. [Display omitted] • The first study of recent brackish water Foraminifera and Ostracoda in surface sediment from Ghana. • First microfossil-based brackish water ecology study in West Africa. • Data base for palaeoenvironmental analyses in Quaternary brackish waters of West Africa. [ABSTRACT FROM AUTHOR]

A 3 week enclosure experiment was carried out at the Gulf of Finland, the Baltic Sea. After additions of inorganic nutrients [nitrogen (N) + phosphorus (P)] and a carbon source (sucrose), we followed bacterial, viral and heterotrophic nanoflagellate (HNF) abundances, as well as bacterial production and the frequency of bacteria visibly infected with viruses. Furthermore, the decay rate of virus particles was measured three times during the enclosure experiment from the KCN-treated water samples. Bacterial mortality caused by viral lysis was estimated using the decay rates and the fraction of bacteria infected. Nutrient (N + P) additions stimulated phytoplankton growth [the chlorophyll (Chl) a concentration increased from <5 μg l-1 up to 19 μg l-1], while sucrose additions increased bacterial production (from 4-6 x 107 l-1 h-1). The phytoplankton blooms affected bacterial production only slightly. Bacterial mortality that was explained by viruses ranged from <2% to 13% when estimated from the visibly infected cells, and from 8% to 808% when the decay rates (range 0.052-0.765 h-1) were used. Assuming a clearance rate of 5 nl flagellate-1 h-1, the HNF community could graze 16-135% of total bacterial loss. [ABSTRACT FROM PUBLISHER]

This article reports that vibrio cholerae is commonly isolated from water in coastal areas where it is considered to be an autochthonous component of estuarine microbial communities. The species has also been isolated from freshwater environments, and isolation rates increase with increased environmental temperature and organic pollution. A private quarantine facility 60 km north of Sydney experienced heavy mortalities of imported goldfish over the summer of 1990-1991. Each month, the facility imported 5000-10000 3 to 4cm goldfish from Singapore for sale on the local market after a 2-week quarantine period. On arrival, the consignments were divided into batches of about 500 fish in separate, aerated 4401 tanks. No additional water circulation or filtration was used. Water was obtained from a local freshwater stream, draining both native forest and mixed agricultural areas, and was not changed during the quarantine period.

(1) A survey of intertidal macrobenthic invertebrates at forty sites in six estuaries in SW Britain was undertaken to identify the key environmental variable which determine the composition of these communities and to provide a prediction of conditions in the Severn estuary should a barrage for the generation of tidal power be built. (2) Multi-dimensional Scaling Ordination of the faunistic data showed that the sites were separated along two principal axes, one determined by static variables (e.g. sediment grain size and organic content) and the other by dynamic variables (i.e. current velocities as indexed by tidal range and wave climate as indexed by the wind fetch distance). (3) The faunistic composition at sites in the Severn estuary is significantly different from the other five estuaries, which by and large are not significantly different from each other. (4) The environment variables responsible for the uniqueness of the Severn are dynamic rather than static, and should be predictable precisely in the post-barrage Severn. (5) Implications for qualitative changes in the fauna are discussed. [ABSTRACT FROM AUTHOR]

A laboratory experiment shows that exopolymer (=mucopolysaccharide) produced by the estuarine marine bacterium Pseudomonas atlantica can be a source of nutrition for the deposit-feeding holothurian Isostichopus badionotus (Selenka). Holothurians fed sediment prepared with C-labeled exopolymer incorporated radioactive carbon into their rete mirabile. [ABSTRACT FROM AUTHOR]

The article discusses the appearance of microscopic algae on the surface of estuarine sediments when exposed by the tide and their disappearance before the return of the tide has been known for a considerable time and recently the phenomenon has been re-investigated on the banks of the River Avon. It is suggested that this is an estuarine phenomenon presumambly since it can readily observed in such situations. It is inferred that the data are compared with that from other experiments and the biological advantages of such a rhythm are briefly discussed.

The article reports on the concept of the Groundwater Recovery and Treatment (GREAT) program, which was designed to manage community water resources as a fully functioning regional water supply system at Oxnard desalination facility in California. It relates that the program aims to reduce the need for imported water by creating facilities that can use brackish groundwater resources and reduce dependence on costly imported water supplies. Moreover, it emphasizes that GREAT is an energy-efficient treatment for brackish local groundwater, producing high-quality potable water that is blended with local groundwater for delivery to customers.

The identification of human artifacts at the early archaeological site of Monte Verde in southern Chile has raised questions of when and how people reached the tip of South America without leaving much other evidence in the New World. Remains of nine species of marine algae were recovered from hearths and other features at Monte Verde II, an upper occupational layer, and were directly dated between 14,220 and 13,980 calendar years before the present (-12,310 and 12,290 carbon-14 years ago). These findings support the archaeological interpretation of the site and indicate that the site's inhabitants used seaweed from distant beaches and estuarine environments for food and medicine. These data are consistent with the ideas that an early settlement of South America was along the Pacific coast and that seaweeds were important to the diet and health of early humans in the Americas. [ABSTRACT FROM AUTHOR]

Strains of Vibrio vulnificus incubated in situ in natural estuarine waters during warm months continued to express katG (periplasmic catalase), rpoS (stress sigma factor), tufA (elongation factor), wza, and wzb (capsule synthesis). vvhA (hemolysin) was differentially expressed between environmental and clinical isolates. These results paralleled our in vitro findings. [ABSTRACT FROM AUTHOR]

This is the first issue of Estuaries and Coasts (ISSN 1559-2723), which continues the Estuarine Research Federation's publication in Estuaries (1978–2005) (ISSN 0160-8347) of scientific reports, reviews, comments, and notes on estuarine and coastal scientific research from around the world. Numbering of volumes of Estuaries and Coasts continues uninterrupted from Estuaries since the expanded title was not intended to mark a change in the scope of the journal. It is our hope that the journal will continue to become more international in its coverage, and to include more coastal science than is sometimes associated with the single word name Estuaries. In addition to the change of the journal's name there is also a new cover design that will change with each issue and highlight an estuary or coast associated with one or more articles in the issue. Another change to the journal is a new column entitled Perspectives in Estuarine and Coastal Science, which is intended to stimulate discussion about emerging topics in estuarine and coastal science. The H. T. Odum Synthesis Essay, initiated in 2005, will be continued on an annual basis. [ABSTRACT FROM AUTHOR]

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Bacteria were investigated for the production of methyl chloride, methyl bromide, and methyl iodide from brackish water. Bacteria were isolated and incubated at 25°C, and the concentrations of methyl halides in the gas phase above cultured samples were determined using dynamic headspace gas chromatography/mass spectrometry. Bacterial growth was monitored by measuring the optical density at 600 nm. Bacteria isolated from brackish water were identified by 16 Svedberg unit ribosomal-ribonucleic acid (16S rRNA) gene sequence analysis. Five genetically different strains of bacteria belonging to Erythrobacter or Pseudomonas produced methyl chloride, methyl bromide, and methyl iodide for several days in the culture. Cultured strains of these genera also released methyl chloride, methyl bromide, and/or methyl iodide. Maximum production rates for methyl halide were observed in the culture of isolated bacteria (HKF-1) belonging to Erythrobacter. The production rates for methyl chloride, methyl bromide, and methyl iodide by HKF-1 were 537 ± 124, 67.4 ± 25.7, and 48.8 ± 9.8 pmol L-1 h-1, respectively. Aquatic bacteria could be a new source of methyl halides in marine environments. [ABSTRACT FROM AUTHOR]

The article examines the cognitive effects of the occupational exposure to the dinoflagellate Pfiesteria, a common inhabitant of estuarine waters in the U.S. mid-Atlantic region in the summer and fall. The results show that the subjects, commercial fishermen, exposed of Pfiesteria likely do not face significant health risks from routine occupational exposure to the organism. Accordingly, the study is identical with similar studies in North Carolina and Virginia in providing reassurance of the health risks of watermen against Pfiesteria.

Abstract: Halacarid mites (Halacaroidea: Halacaridae) are meiobenthic organisms. The majority of species and genera are marine, only few are restricted to freshwater. Halacarid mites are present from the tidal area to the deep sea. It is the only mite family completely adapted to permanent life in the sea. The first record was published more than 200 years ago. At present, 51 marine and brackish water genera of halacarid mites are known, including more than 1000 species. The genera are Acanthohalacarus, Acanthopalpus, Acarochelopodia, Acaromantis, Acarothrix, Actacarus, Agaue, Agauides, Agauopsis, Anomalohalacarus, Arenihalacarus, Arhodeoporus, Atelopsalis, Australacarus, Bathyhalacarus, Bradyagaue, Camactognathus, Caspihalacarus, Coloboceras, Colobocerasides, Copidognathides, Copidognathus, Corallihalacarus, Enterohalacarus, Halacarus, Halacarellus, Halacaroides, Halacaropsis, Halixodes, Isobactrus, Lohmannella, Metarhombognathus, Mictognathus, Parhalixodes, Pelacarus, Peregrinacarus, Phacacarus, Rhombognathides, Rhombognathus, Scaptognathides, Scaptognathus, Simognathus, Spongihalacarus, Thalassacarus, Thalassarachna, Thalassophthirius, Tropihalacarus, Werthella, Werthelloides, Winlundia, and Xenohalacarus. The guide, which includes marine and brackish water genera, starts with an introduction to methods of collection, extraction and examination of halacarid mites, an outline of the external morphology and life history, and an overview of the commonly used terminology. Both a dichotomous key and tabular keys to the genera are presented. The keys have been prepared on the basis of adults. In general, in adults and nymphs the outline of idiosoma, gnathosoma and legs is similar, whereas the outline of plates, the sculpturing and number of setae on idiosoma and legs differ. In the tabular keys idiosoma, gnathosoma, palps, legs, tarsi and shape of claws are treated separately. The major part of the guide deals with descriptions of the 51 genera. Each genus is diagnosed and illustrated, namely a dorsal and ventral aspect of the idiosoma, the gnathosoma, leg I and tarsi I, II and IV. The diagnoses mention both, characters expected to be relevant in a phylogenetic sense and those thought to be mainly correlated with environment and mode of life. Rare character variants are included in the diagnoses; more variants are expected to be found in the future. In addition to the diagnoses, short notes are given on biology and geographical distribution, on similar-looking genera, and distinguishing characters. At the end of the presentation of a genus, relevant and most recent descriptive or phylogenetic references are listed. Full article published online at: http://www.senckenberg.de/odes/06-06.htm [Copyright &y& Elsevier]

Reports that the Estuarine and Brackish-Water Services Association is organizing a residential course on estuarine hydrography and the measurement of dilution scheduled in September 1978. Course outline; Venue; Fee; Contact information.