The accumulation of debris is an insidious problem throughout the world’s oceans. Here we document 234.24 items of macro-debris/km² in the shallow populated parts of Majuro lagoon (Republic of the Marshall Islands) which is the second highest standing stock of macro-debris recorded to date in any benthic marine habitat in the world. The majority of macro-debris was from household sources (78.7%) with the peak abundance recorded in areas of medium affluence. Marine debris causes suffocation, shading, tissue abrasion and mortality of corals and we show a significant negative correlation exists between the level of hard coral cover and coverage of marine debris. Given long decomposition times, even if the input of rubbish to Majuro lagoon is stopped immediately, the standing stock of debris will persist for centuries. Multiple new initiatives are needed to curtail the direct and indirect dumping of waste in Majuro lagoon.

The Seine’s estuary (France) waters are the receptacle of effluents originating from wastewater treatment plants (WWTP). In this estuary, mudflats are deposition zones for sediments and their associated contaminants, and play an essential role in the mercury (Hg) biogeochemical cycle mainly due to indigenous microorganisms. Microcosms were used to assess the impact of WWTP-effluents on mercury methylation by monitoring Hg species (total dissolved Hg in porewater, methylmercury and total mercury) and on microbial communities in sediments. After effluent amendment, methylmercury (MeHg) concentrations increased in relation with the total Hg and organic matter content of the WWTP-effluents. A correlation was observed between MeHg and acid-volatile-sulfides concentrations. Quantification of sulfate-reducing microorganisms involved in Hg methylation showed no increase of their abundance but their activity was probably enhanced by the organic matter supplied with the effluents. WWTP-effluent spiking modified the bacterial community fingerprint, mainly influenced by Hg contamination and the organic matter amendment.

Body distribution and growth- and nutritional status-dependent accumulation of 21 trace elements were investigated in harbor seals (Phoca vitulina) stranded in the North Sea coast in 2002. Higher concentrations and burdens of Mn, Se, Mo, Ag, Sn, Hg, and Bi in the liver, Cd in the kidney, As in the blubber, and Co, Sr, and Ba in the bone were observed. Significant positive correlations of hepatic Se, Mo, Ag, Cd, Sn, Hg, Tl, and Bi with standard body length were found, while significant negative relationships were detected for Mn, As, Rb, Sr, and Sb in the liver. Concentrations of Co, Se, Sr, Sn, Hg, and Bi in the liver, V, Sr, Ag, Sn, and Hg in the kidney, V, Mn, Co, Rb, Sr, Sn, Ba, and Pb in the blubber increased with decreasing blubber thickness of harbor seals, indicating enrichment of these elements in the target tissue by emaciation.

Environmental pollution due to heavy metals is having an increased impact on marine wildlife accentuated by anthropogenic changes in the planet including overfishing, agricultural runoff and marine emerging infectious diseases. Sea turtles are considered sentinels of ecological health in marine ecosystems. The objective of this study was to determine baseline concentrations of zinc, cadmium, copper, nickel, selenium, manganese, mercury and lead in blood of 22 clinically healthy, loggerhead turtles (Caretta caretta), captured for several reasons in Puerto López Mateos, Baja California Sur, Mexico. Zinc was the most prevalent metal in blood (41.89μgg⁻¹), followed by Selenium (10.92μgg⁻¹). The mean concentration of toxic metal Cadmium was 6.12μgg⁻¹ and 1.01μgg⁻¹ respectively. Mean concentrations of metals followed this pattern: Zn>Se>Ni>Cu>Mn>Cd>Pb and Hg. We can conclude that blood is an excellent tissue to measure in relatively non-invasive way baseline values of heavy metals in Caretta caretta.

This study determined the concentrations of major and trace elements in shellfish (oysters, clams and mussels) and conducted an assessment of the health risks due to the consumption of contaminated seafood. Samples were collected at 34 sites along Todos os Santos Bay, Brazil. The elements were determined by ICP OES and Hg by Direct Mercury Analysis. Relatively high concentrations of trace elements (As, Zn, Se and Cu) were found in seafood tissues. Potential daily intake of As, Co, Se, Zn and Cu associated to shellfish consumption suggested relevant non-carcinogenic risk for all studied locations. Copper was the element that posed the greatest non-carcinogenic risk, while Pb posed the highest carcinogenic risk. Health risks for humans were greatest from the consumption of mussels. Contaminated shellfish offer the greatest risk for children, subsistence fishers and subsistence shellfish consumers.

In Korea, the new permission criteria for industrial effluents based on Daphnia magna acute toxicity tests will be gradually implemented starting from 2011. Thus, in this study, toxicity assessment and identification using a marine species (Tigriopus japonicus) and the freshwater species (D. magna) was comparatively investigated. Effluent from an acid mine drainage treatment plant showed acute toxicity toward both organisms due to low pH, which was removed by neutralization of the effluent. Additionally, evaluation of the effluent of an electronics company revealed that Cu was attributable to the observed toxicity, and the effluent was more toxic toward T. japonicus than D. magna. Moreover, effluents from a metal plating factory were acutely toxic toward D. magna (6.50 TU), while they were not toxic against T. japonicus. Toxicity identification revealed that the high level of Cl⁻ (12,841mgL⁻¹) was the cause of toxicity. Thus, the effluents had no effect on the marine species, T. japonicus. These findings suggest that a marine species rather than a freshwater species is more desirable for toxicity assessment of industrial effluent discharged into the saltwater, and thus should be considered in the legislation of toxicity-based discharge limits in Korea.

In this study, zebrafish embryos were exposed to titanium dioxide nanoparticles (TiO₂ NPs at 0.1, 0.5, 1, 5, 10mg/L or control) from fertilization to free swimming stage. Hatchability, survival, and malformation rate were not affected by TiO₂ NPs at these exposure levels. However, larval swimming parameters, including average and maximum velocity and activity level were significantly affected by TiO₂ NPs. Co-exposure to either the glutathione precursor, N-acetylcysteine (NAC), or the glutathione synthesis inhibitor, buthionine sulfoximine (BSO), did not significantly alter the behavioral effects resulting from TiO₂ NPs, suggesting that other factor(s) besides oxidative stress may contribute to the behavioral toxicity of TiO₂ NPs. Our study also demonstrated that the behavioral endpoints were more sensitive than the others (e.g., hatchability and survival) to detect toxicity of TiO₂ NPs on developing fish.

Perchlorate is a widespread contaminant in the aquatic environment. In the present work, the expressions of deiodinase enzymes (d1, d2, and d3) and sodium iodide symporter (nis) genes were determined after larval and adult rare minnow (Gobiocypris rarus) exposed to 5 and 50μg/L perchlorate for 21days. The results showed that deflation of swim bladder development was observed in larvae at 50μg/L perchlorate treatment. An up-regulation of the d2 and nis mRNA levels were observed in the larve and in brain of adults. Meanwhile the expressions of d3 mRNA levels were significantly down-regulated in the liver. These results indicate the changes in d2, nis, and d3 mRNA expression brings about increased outer-ring deiodination, idodine uptake, and a further decrease of inner-ring deiodination, respectively reflecting auto-regulation of hypothalamic-pituitary-thyroid (HPT) axis in adult after perchlorate exposure. The larval fish development could be affected by perchlorate at environmentally relevant concentrations.

The concentrations of ten trace metals were determined in the gills, muscles, hepatopancreas, and exoskeleton tissues of Xenograpsus testudinatus that lives around shallow and acidic hydrothermal vents off Kueishan Island, northeastern Taiwan. The analytical results demonstrate that the metal concentrations vary significantly with the type of crab tissue. The concentrations of Al, Cd, Co, Cu, Fe, Ni, and Zn are highest in the gills, whereas the concentration of Mn is highest in the exoskeleton. Cr and Pb concentrations are similar across the different tissues. The enhanced accumulation of most metals in the gills suggests the metal accumulation via the respiration pathway rather than the uptake of food. The results also reveal that the distribution patterns of metals in tissues are similar in the hepatopancreas and muscles, but very different in both the gills and the exoskeleton, perhaps because of the different pathways of metal utilization in the different crab tissues.

Observations are presented on dilution and dispersion rates of ballast water discharged under normal operational conditions at the semi-enclosed port of Goderich, Ontario. The ballast water was tagged with Rhodamine-WT dye and microscopic magnetically-attractive tracer particles. Maximum concentrations of dye immediately after discharge were diluted to 1–5% of initial ballast tank concentrations, and within 3days had decreased to less than 0.1% of initial concentrations. Inside the harbor, there was 10–20% of the ballast water still present after 2days, consistent with a flushing rate of 0.8–1.15day⁻¹. Magnetic particles were collected up to 7.5km outside the harbor after one day, consistent with a dilution factor of order 10⁵ outside the harbor. The results of this study are discussed in the context of ballast water discharge standards proposed by the International Maritime Organization to minimize the introduction of aquatic nonindigenous species through ships’ ballast water and sediments.