The impacts of pollution on marine organisms are often investigated using the viability of their haemocytes. Although this assay is routinely used in monitoring, field and laboratory experimentation, there has been less effort in further optimizing procedures to reduce artefacts and facilitate sampling over large geographic areas.Using the oyster Saccostrea glomerata as a model species, we investigated the effects of different techniques for extracting haemolymph, period of incubation with dye and emersion-time (e.g. tidal-state) on the viability of haemocytes. Collecting haemocytes with a syringe, through a drilled hole in the shell, increased the viability of haemocytes by almost 50%. While emersion-time and incubating haemocytes with the dye for up to 4h did not affect viability.This simple in situ approach provides a less destructive method for extracting haemocytes, allowing their viability to be measured as part of large-scale experiments without jeopardizing the surrounding assemblage of animals and plants.

Thallium is a highly toxic metal whose biogeochemical behaviour in the marine environment is poorly understood. We measured Tl in sediments, macroalgae (Fucus vesiculosus and Fucus ceranoides) and deposit-feeding invertebrates (Hediste diversicolor, Arenicola marina and Scrobicularia plana) from two estuaries of south west England (Plym and Fal) draining mineralised catchments. In the Plym, and for a given sample type, concentrations of Tl were rather invariant between sample locations and averaged about 500μgkg−1 for sediment, 30μgkg−1 for macroalgae and 10μgkg−1 for the invertebrates. In the Fal, respective concentrations were of a similar order of magnitude but exhibited greater variation between sample locations. Normalisation of Tl concentrations to K, the biogeochemical analogue of Tl+, revealed bioenrichment of about 20 for all organisms in the Plym and bioenrichment ranging from about 3 (H. diversicolor) to 170 (F. ceranoides) in the Fal. Despite the low bioaccumulation of Tl relative to other metals measured concurrently, it is recommended that Tl be more closely monitored and better studied in the estuarine environment.

Total concentrations, chemical fractions by BCR procedure and enrichment factors of nine potential harmful elements (V, Cr, Co, Ni, Cu, Zn, Mo, Cd and Pb) in surface sediments of the East China Sea (ECS) were investigated. Spatial distributions illustrated that PHEs (potential harmful elements) were mainly from the Changjiang River and the Jiangsu coastal current, except Pb which was influenced by atmospheric input. Sediments in the ECS were moderately polluted with Cd, Pb, Zn and Cu according to their enrichment factors (EFs). Distributions of EFs and labile fractions revealed that anthropogenic Cd and Cu were mainly input though the Changjiang, Pb pollutant was delivered from the Changjiang and atmosphere, while Zn was impacted by terrestrial pollution from the Changjiang and the Hangzhou Bay. Budget calculation showed that the Changjiang contributed 82–90% of PHE influxes. Thirty-eight to 77% of PHEs were buried in sediment, mainly along the inner shelf.

Remediation of coastal habitats from impacts such as dredging and excavation in Gulf coastal waters is hampered by a lack of information on natural recolonisation rates and recruitment patterns of subtidal biota. For soft substrate habitats recovery information is only available for severely polluted sites where recovery takes many years (Jones et al., 2008).Construction of the Sabah Al-Ahmad Sea City provides a unique opportunity to follow benthic recruitment and community development on a range of artificially created benthic habitats over time. The three phases completed were each flooded by the sea separately and annual ecological surveys allow comparison of colonisation patterns and community development rates over time.Species diversity similar to that seen in comparable natural open sea habitats is reached within 2–5years for mixed sand/rock biota, but longer (2–6years) for sand biota. Biotic abundance exceeds open sea levels within 1–2years due to settlement of opportunistic species. Coral recruitment occurred within 3years. Present data provides a reference point for recovery rates into none polluted benthic habitats for the Gulf.

Estuaries are increasingly under threat from a variety of human impacts. Recreational and commercial boat traffic in urban areas may represent a significant disturbance to fish populations and have particularly adverse effects in spatially restricted systems such as estuaries. We examined the effects of passing boats on the abundance of different sized fish within the main navigation channel of an estuary using high resolution sonar (DIDSON). Both the smallest (100–300mm) and largest (>501mm) size classes had no change in their abundance following the passage of boats. However, a decrease in abundance of mid-sized fish (301–500mm) occurred following the passage of boats. This displacement may be attributed to a number of factors including noise, bubbles and the rapidly approaching object of the boat itself. In highly urbanised estuarine systems, regular displacement by boat traffic has the potential to have major negative population level effects on fish assemblages.

Continuous radon (222Rn) monitoring was conducted at two stations (site A and site B) with different perpendicular distance from the shoreline in Xiangshan Bay, East China Sea. Based on a 222Rn balance model (various sources and sinks of 222Rn in coastal water), the average rate of SGD was estimated to be 0.69cm/day and 0.23cm/day for site A and site B, respectively. The results from a nutrient analysis of the groundwater indicate that the associated nutrients fluxes loading through the SGD pathway were 4.27×106mol/day for DIN, 2.24×104mol/day for DIP and 1.82×106mol/day for DSi, respectively, which were comparable to or even higher than the levels observed in the local streams. Therefore, adequate attention should be paid to the importance of SGD as one source of nutrients during the eutrophication control process in this area.

We report a large cyst bed of the potentially toxic and bloom-forming dinoflagellate Alexandrium tamarense species complex in bottom sediments from the port of Halifax, Nova Scotia, Canada. The average cyst concentrations of that species ranged from 4033±2647 to 220872±148086cystsg−1 of dry sediments and the highest concentrations were found near ship terminals in Bedford Basin. Although this species is endemic to this region, our work strongly suggests that some of the cysts of A. tamarense species complex found in the port of Halifax were introduced through discharged ballast water and sediments.

Nine macroalgal blooms were studied in five coastal lagoons of the SE Gulf of California. The nutrient loads from point and diffuse sources were estimated in the proximity of the macroalgal blooms. Chlorophyll a and macroalgal biomass were measured during the dry, rainy and cold seasons. Shrimp farms were the main point source of nitrogen and phosphorus loads for the lagoons. High biomasses were found during the dry season for phytoplankton at site 6 (791.7±34.6mgm−2) and during the rainy season for macroalgae at site 4 (296.0±82.4gm−2). Depending on the season, the phytoplankton biomass ranged between 40.0 and 791.7mgm−2 and the macroalgal biomass between 1 and 296.0gm−2. The bulk biomass (phytoplankton+macroalgal) displayed the same tendency as the nutrient loads entering the coastal lagoons. Phytoplankton and macroalgal biomass presented a significant correlation with the atomic N:P ratio.

Eutrophication is a global environmental problem. Better management of this threat requires more accurate assessments of anthropogenic nitrogen (N) inputs to coastal systems than can be obtained with traditional measures. Recently, primary producer N isotopic signatures have emerged as useful proxy of such inputs. Here, we demonstrated for the first time the applicability of this method using the widespread eelgrass (Zostera marina) in the highly eutrophic Baltic Sea. Spatial availability of sewage N across a bay with one major sewage outflow predicted by eelgrass δ15N was high near and downstream of the outflow compared to upstream, but returned to upstream levels within 4km downstream from the outfall. General conclusions were corroborated by traditional eutrophication measures, but in contrast to these measures were fully quantitative. Eelgrass N isotope ratios therefore show high potential for coastal screens of eutrophication in the Baltic Sea, and in other areas with eelgrass meadows.

Surface water samples were collected from substations along Sheva creek and Dharamtar creek mangrove ecosystems of Uran (Raigad), Navi Mumbai, west coast of India. Water samples were collected fortnightly from April 2009 to March 2011 during spring low and high tides and were analyzed for pH, Temperature, Turbidity, Total solids (TS), Total dissolved solids (TDS), Total suspended solids (TSS), Dissolved oxygen (DO), Biochemical oxygen demand (BOD), Carbon dioxide (CO2), Chemical oxygen demand (COD), Salinity, Orthophosphate (O-PO4), Nitrite–nitrogen (NO2–N), Nitrate–nitrogen (NO3–N), and Silicates. Variables like pH, turbidity, TDS, salinity, DO, and BOD show seasonal variations. Higher content of O-PO4, NO3–N, and silicates is recorded due to discharge of domestic wastes and sewage, effluents from industries, oil tanking depots and also from maritime activities of Jawaharlal Nehru Port Trust (JNPT), hectic activities of Container Freight Stations (CFS), and other port wastes. This study reveals that water quality from mangrove ecosystems of Uran is deteriorating due to industrial pollution and that mangrove from Uran is facing the threat due to anthropogenic stress.