Between 1972 and 2009, evidence of red tide outbreaks in the Yangtze River Estuary and adjacent waters was collected. A geographic information system (GIS) was used to analyze the temporal and spatial distribution of these red tides, and it was subsequently used to map the distribution of these events. The results show that the following findings. (1) There were three red tide-prone areas: outside the Yangtze River Estuary and the eastern coast of Sheshan, the Huaniaoshan–Shengshan–Gouqi waters, and the Zhoushan areas and eastern coast of Zhujiajian. In these areas, red tides occurred 174 total times, 25 of which were larger than 1000 km2 in areal extent. After 2000, the frequency of red tide outbreaks increased significantly. (2) During the months of May and June, the red tide occurrence in these areas was 51% and 20%, respectively. (3) Outbreaks of the dominant red tide plankton species Prorocentrum dong-haiense, Skeletonema costatum, Prorocentrum dantatum, and Noctiluca scientillan occurred 38, 35, 15, and 10 times, respectively, during the study interval.

Algal assay using marine microalgae has emerged as an important method to evaluate the toxicity of chemicals, which is currently undertaken using conventional culture and additional detection of physiological cellular endpoints. While effective, this approach can be labor-intensive and thus could benefit from a more streamlined, integrated approach. Microfluidics offers a way to accomplish this goal. Here, we demonstrate a microfluidic device which consists of a concentration gradient generator (CGG), diffusible culturing module and power-free valve system. It allows the processes of chemical liquid dilution and diffusion, micro-scale microalgal culture (in batch or chemostatic conditions), cell stimulation and on-lined screening to be integrated into a single device. Using the device, marine microalgae were successfully cultured and stressed on-chip. The simple assay provides multi-biological response measurements of cell division rate, autofluorescence and esterase activity. This work showed promising in developing a microfluidic platform for toxicity screening based on marine microalgal culture.

The aim of this study was to examine the temporal and spatial total column ozone distribution in West Africa using Total Ozone Mapping spectrometer (TOMS) daily data for five years between 2001 and 2005 in fifteen locations. In this study, certain significant observations emerged: weather activity particularly the rainfall producing mechanism (dynamic of the wind systems) was responsible for about 62% ozone distribution in the region. Ozone maximum and minimum concentrations over all the stations were 305 DU and 232 DU respectively producing an average range of 73 DU (only about 27.03% of the mean value). Ozone has a seasonal distribution with minimum occurring during the dry season and maximum occurring during the wet season. A decreasing rate of about –0.6 DU/year was found for the region. Interannual ozone characteristics revealed an oscillating feature similar to Quasi – biennial Oscillation (QBO) footprints which indicated the importance of stratosphere – troposphere exchange to ozone distribution in the region. Furthermore, lag of about one or two months occurs between south (lower latitude) and north (higher latitude) monthly ozone maximums.

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.