The aims of the present study were to investigate the effects of mariculture activities on inorganic mercury (Hg²⁺) adsorption/desorption on sediments and the distributions of newly adsorbed Hg²⁺ on different chemical fractionations. The adsorption amount and binding energy of Hg²⁺ on mariculture sediment (MS) were significantly higher (p<0.05) than reference sediment (RS). This may be explained by the strong complexation role that exists between Hg²⁺ and organic matter (OM), which derived from unconsumed fish feed and fish metabolites. The reducible Hg²⁺ in MS was significantly lower (p<0.01) than RS, which may have been caused by the decreasing amount of iron and manganese hydroxide in MS, lead to the decrease of Hg²⁺ bound to them. On the contrary, the residual Hg²⁺ was significantly higher (p<0.01) in MS than RS, which suggests that newly adsorbed Hg²⁺ was more stable in MS than RS.

Polyethylene pellets provide a convenient means to monitor Persistent Organic Pollutants (POPs) in marine systems. Pellets collected between 1984 and 2008 at three South African beaches were analysed for PCB, HCH and DDT. Concentrations of all three POPs decreased over the last two decades, although this signal was less clear for PCBs, and further monitoring is needed to assess trends in this family of compounds. DDT concentrations at two sites were higher than previous records for southern Africa, but there is no evidence of a link to the ongoing use of DDT for malaria control. HCHs concentrations were lower than in pellets from the east coast of southern Africa, suggesting that this pesticide was mainly used in the eastern part of the region. Our study demonstrates the potential for International Pellet Watch to track temporal as well as geographical patterns in the abundance of POPs in marine environments.

An integrated study was conducted to determine the presence of phenolic and steroid endocrine-disrupting compounds (EDCs), in the marine environment of Thermaikos Gulf, Northern Aegean Sea, Greece. Seawater, suspended particulate matter, sediments and biota were examined for nonylphenol, octylphenol, their mono- and diethoxylate oligomers, bisphenol A, estrone, 17α-estradiol, 17β-estradiol, estriol, mestranol and 17 α -ethynylestradiol. Phenolic compounds were detected in all of the compartments, with nonylphenol and its ethoxylates being the dominant pollutants. The occurrence of nonylphenol in sediments presents a significant risk to the biota. Mussels exhibited relatively low concentrations and low bioconcentration factors for NP and OP. The effect of terrestrial sources of the EDCs on the marine environment is discussed. The influence of suspended particulate matter and organic carbon in the partition of the EDCs between the dissolved and the particulate phase was investigated.

This study investigates the potential for leaching of coal trace elements to seawater from a grounded bulk carrier. The coal type and ecological scenario was based on the grounding of the “Shen Neng” (April 2010) at Douglas Shoal located within the Great Barrier Reef (Queensland, Australia). The area is of high ecological value and the Queensland Water Quality Guidelines (2009) provided threshold limits to interpret potential impacts. Coal contains many trace elements that are of major and moderate concern to human health and the environment although many of these concerns are only realised when coal is combusted. However, “unburnt” coal contains trace elements that may be leached to natural waterways and few studies have investigated the potential ecological impact of such an occurrence. For example, coal maritime transport has increased by almost 35% over the last five reported years (Jaffrennou et al., 2007) and as a result there is an increased inherent risk of bulk carrier accidents. Upon grounding or becoming submerged, coal within a bulk carrier may become saturated with seawater and potentially leach trace elements to the environment and impact on water quality and ecological resilience. The worst case scenario is the breakup of a bulk carrier and dispersal of cargo to the seafloor.

Boring isopods damage expanded polystyrene floats under docks and, in the process, expel copious numbers of microplastic particles. This paper describes the impacts of boring isopods in aquaculture facilities and docks, quantifies and discusses the implications of these microplastics, and tests if an alternate foam type prevents boring. Floats from aquaculture facilities and docks were heavily damaged by thousands of isopods and their burrows. Multiple sites in Asia, Australia, Panama, and the USA exhibited evidence of isopod damage. One isopod creates thousands of microplastic particles when excavating a burrow; colonies can expel millions of particles. Microplastics similar in size to these particles may facilitate the spread of non-native species or be ingested by organisms causing physical or toxicological harm. Extruded polystyrene inhibited boring, suggesting this foam may prevent damage in the field. These results reveal boring isopods cause widespread damage to docks and are a novel source of microplastic pollution.

The Great Barrier Reef (GBR) is a World Heritage Area and contains extensive areas of coral reef, seagrass meadows and fisheries resources. From adjacent catchments, numerous rivers discharge pollutants from agricultural, urban, mining and industrial activity. Pollutant sources have been identified and include suspended sediment from erosion in cattle grazing areas; nitrate from fertiliser application on crop lands; and herbicides from various land uses. The fate and effects of these pollutants in the receiving marine environment are relatively well understood. The Australian and Queensland Governments responded to the concerns of pollution of the GBR from catchment runoff with a plan to address this issue in 2003 (Reef Plan; updated 2009), incentive-based voluntary management initiatives in 2007 (Reef Rescue) and a State regulatory approach in 2009, the Reef Protection Package. This paper reviews new research relevant to the catchment to GBR continuum and evaluates the appropriateness of current management responses.

This study quantifies benthic nutrient fluxes and sedimentation rates in the Ahe Atoll lagoon (French Polynesia), in two stations located under pearl oyster frames, and two control stations away from the pearl culture facility. Dissolved inorganic nitrogen fluxes ranged between 2 and 35μmolNm⁻²h⁻¹ and Soluble Reactive Phosphorus varied between −3 and 8.2μmolPm⁻²h⁻¹. Particulate sedimentation rates beneath the oysters were approximately five times higher than in the control zone and the percentage of small particles (⩽63μm) were about the twice. In contrast, sediment composition was similar under and outside the direct influence of oyster frames. In this ecosystem, where primary production is dependent on the available nitrogen, our study revealed that, while highly variable, benthic fluxes could sometimes contribute up to 28% of the nitrogen demand for primary production.

Responses of biological indices and oxidative stress biomarkers were studied in the giant clam Tridacna maxima and in the fish Epinephelus merra collected from two sites differing by their level of contamination in the French Polynesian Moorea island. Higher levels of catalase (CAT), glutathione-S-transferases (GST) and thiobarbituric acid reactive substances (TBARs) were observed in the hepatopancreas of T. maxima and in the liver of E. merra compared to muscle. CAT and TBARs levels were significantly higher in the hepatopancreas of clams collected from the impacted site (Vaiare) compared to the reference site (bay of Cook). The same pattern was observed for TBARs levels in the liver of E. merra. These results indicate that both organisms from the impacted site were exposed to contaminants leading to an oxidative stress and demonstrate, for the first time, the usefulness of T. maxima and E. merra as sentinel species for biomonitoring reef environments.