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The aim of this study was to investigate the effect of malachite green on the post-exposure filtration rate of Blood Clam, Barbatia virescens. Blood Clams were collected from the rocky coast and acclimated to laboratory conditions for 18 days. Bioassays were conducted wherein Blood Clams were exposed for 24 h to a clean medium (no malachite green), 0.06 mg l-1 malachite green, 0.32 mg l-1 malachite green, 5.06 mg l-1 malachite green, and then to the same concentrations for 48 h. Filtration rate in all concentrations and malachite green-exposure durations were determined at 0.5, 1, 2, 3, 4, and 6 h. Blood Clams exposed for 24 h and 48 h to 0.32 and 5.06 mg l-1 had significantly lower filtration rates than the control (p<0.05). Similarly, those exposed to 0.06 mg l-1 for 48 h showed significant reduction in their filtration rates. The lower rate was associated with longer exposure to malachite green. In addition, Blood Clams exposed for 48 h were not able to improve their filtration rate, although they were transferred to a clean medium for 6 h. The green colouration on Blood Clams' muscles was also not eliminated. These findings suggest the ecological risk of malachite green to bivalves and its implications to the health of sessile coastal organisms. [ABSTRACT FROM AUTHOR]

The object of this study was to identify the accumulation patterns of Cu, Pb, Zn and Cd in different consumers living in the Pearl River Estuary. Concentrations of metals in water, sediments and tissues of demersal fish, crustaceans and molluscs were determined. Cluster analysis and principal component analysis were used to evaluate accumulation patterns of these four metals among species. Fish species were clustered as a group which was characterized by low accumulation of Cu, Zn and Cd. By contrast, crustaceans and molluscs were clustered to another group which was characterized by high accumulation of Cu, Zn and Cd. However, no significant difference of Pb accumulation between the two groups was identified. In addition, the concentrations of the four metals in fish were strongly correlated with metal concentrations in sediments, indicating that the sediment was the source of heavy metals in fish. Moreover, the accumulation of a heavy metal in fish was correlated with the same metal element and other heavy metals in the sediments. This may demonstrate a tendency of cross-acclimation in fish to different metals within the special habitat from the Pearl River Estuary. Dietary attention should be paid to the high concentrations of Pb in fish and crustaceans. [ABSTRACT FROM AUTHOR]

The coastal ecosystems of the northwestern Arabian Gulf mostly consist of low lying tidal flats backed by hyper saline marsh (sabkha) and desert. As populations increased, much of this coast has been subject to infill and seaward extension for housing, recreation and industrial development. This has led to degradation of the highly productive intertidal and shallow subtidal marine ecosystems upon which fisheries depend. Further degradation can be expected with future sea level rise, as high evaporation rates will induce hyper saline conditions. Rather than building out into the sea using dredging and infill, an alternative approach is to construct cities on land, safely above future high water levels, by excavating saline desert of low productivity to create marine waterways. Sabah Al-Ahmad Sea City in Kuwait was first connected to the sea in 2004 and, with 3 phases completed, now has 84 km of shoreline in the desert. The waterway system was modeled before excavation and relies solely upon tides and wind for seawater circulation. To date seawater quality has been excellent, meeting all criteria demanded by the Environment Public Authority. Within the waterways, a full range of man-made marine habitats have been created. These include intertidal beaches, tidal flats, mangrove and salt marshes on islands, together with subtidal sand and rock benthic habitats. These have been monitored with daily physical and annual biological surveys. Importantly, this data provides new information on the natural colonization rates and development of Gulf soft substrate intertidal and subtidal marine communities. Within 5 years of opening to the sea, all artificially created marine habitats have a species richness and abundance close to, or exceeding, that of similar open sea natural habitats in Kuwait. Over 1000 species of macrobiota now exist within the desert waterways including 100 species of fish and shellfish. Present work describes the development of these marine communities and provides a baseline for recruitment rates of Gulf marine fauna into non-polluted habitats. [ABSTRACT FROM AUTHOR]

Coastal wetlands are important contributors to large-lake productivity and biodiversity and mediators of lake—watershed interactions. This study explores whether the size of the watershed in which coastal wetlands are embedded (a measure of strength of connection to the terrestrial landscape) influences their background condition and response to anthropogenic landuse. Water quality, substrate, vegetation structure, and composition of zoobenthos, turtles, crayfish, and fish were characterized in 32 Lake Superior coastal wetlands in the summers of 2000–2001, and related to watershed size categories via ANOVA and to watershed development (percent agricultural and urban landuse) via linear regression. Lake Superior coastal wetlands had relatively low levels of watershed development – apparently not enough to significantly alter fish composition. However, watershed development was associated with significant changes in substrate, turbidity, plant structure, and zoobenthos, and in most cases these effects were stronger in wetlands having big rather than small watersheds. An alternate classification contrasting exposure to versus protection from river influences was not effective at resolving responses to watershed development. Watershed size had little effect on background conditions in minimally disturbed wetlands, although turtles were more abundant in large-watershed wetlands. The role of watershed size in mediating responses to landuse merits further study, but our findings suggest that receiving inflows from bigger watersheds affects coastal wetlands primarily by amplifying transmission of disturbance rather than via direct impacts of flow. [ABSTRACT FROM PUBLISHER]

The Scottish Environment Protection Agency (SEPA) has developed, and runs, real-time bathing water quality predictions at ten sites throughout Scotland since 2004. Daily bathing water quality predictions are posted on electronic variable message signs at 10 beach locations networked to a central communication centre and updates are simultaneously made on the SEPA website, phone and text message service. Antecedent rainfall and subsequent river flow can significantly increase the concentrations of faecal indicator organisms in bathing waters. The SEPA signage prediction tool, an Excel spreadsheet based model, was developed and used to set site-specific criteria for rainfall and river flow to predict bathing water quality based on historical data. Real-time predictions against the current EU Bathing Water Directive were correct or precautionary on 99% of days and correct for 82% of compliance samples during 2007, and 81% of compliance samples during the 2008 season. The revised 2006 Directive sets out more stringent bathing water quality standards which require increased model performance. New predictive models are now being trailed using decision tree statistical software and are intended to replace the existing prediction tool by 2012. [ABSTRACT FROM AUTHOR]

Global ports are hubs for industrial activities and trade. In consequence, sediments and water in these areas are often contaminated by an array of chemicals. Sediments also harbour both living, active stages and various diapausing or resting stages of biota. International shipping activities move sediments containing these biotic stages around the world, possibly resulting in biological contamination of port areas. In this study we assess active and resting stages of invertebrates contained in ballast sediment of transoceanic vessels operating on the North American Great Lakes to determine if ballast sediments could serve as a vector of nonindigenous species. A cumulative total of 160 species were identified, including 22 freshwater species not recorded from the Great Lakes' basin. Hatch rates of resting stages are affected by thermal conditions, thereby affecting invasion success. Total abundance and species diversity of freshwater invertebrate animals hatched from resting stages were negatively related to salinity of residual water in ballast tanks from which the sediments were obtained, suggesting that ballasting a shallow lens of saltwater may provide some degree of risk reduction from freshwater species invasions. [ABSTRACT FROM AUTHOR]