Histopathological alterations can indicate time-integrated impacts on organisms stemming from alterations at lower biological organisation levels. Long-term (native mussels) and short-term (transplanted clams) changes in the tissues of molluscs exposed to the effluents from two land-based marine fish farms (LBMFFs) were determined. Histological alterations were related to the δ¹⁵N isotopic signal measured in mussels and macroalgae. Effluents from LBMFFs were found to cause severe and moderate gill filament exfoliation in clams and mussels, respectively. Some transplanted clams showed severe degrees of hemocytic phagocytosis in gonads and connective tissue. In an attempt to semi-quantitatively summarize the observed histopathological alterations, a weighted index of damage (WID) was calculated for each type of alteration, species and sampling site. The WID was clearly related to the δ¹⁵N descriptor of exposure. Further studies aimed at standardizing this relationship may establish critical thresholds of the descriptor for its implementation within environmental monitoring plans for LBMFFs.

The use of sonar by military vessels during military exercises may produce acoustic pollution of the marine environment. States have an obligation under international law to reduce and control this form of pollution. Regulation of the use of sonar is rendered more complex by the specific regime applicable to warships, i.e. sovereign immunity. Immunity however does not prevent in all cases action by States other than the flag State, notwithstanding the limitations imposed by Art. 236 of the United Nations Convention on the Law of the Sea. More importantly, immunity does not prevent the flag State from taking measures to reduce pollution caused by its own warships. Under some environmental treaties, flag States not only may, but have the obligation to adopt measures.

The endocrine-disrupting chemicals (EDCs) was investigated in 28 riverine sediments from the Pearl River system, China and analyzed by an ultrasonication extraction and GC–MS method. The concentrations of 4-tert-octylphenol (OP), 4-nonylphenol (NP), and bisphenol A (BPA) in the sediments were in the ranges of <2.0–210, 107–16198 and <1.7–430ng/g dw, respectively. The steroid estrogens estrone (E1) and 17β-estradiol (E2) in the sediments ranged from <1.3 to 10.9ng/gdw and from <0.9 to 2.6ng/gdw, respectively. The spatial distribution of these chemicals was related to the discharge of domestic and industrial wastewater along the rivers. The positive correlation between EDCs and total organic carbon indicates that sedimentary organic carbon is an important factor in controlling the distributions of EDCs. Compared with other previous studies, the ZR and DR rivers from the PRD were heavily contaminated by APs and BPA.

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.

To rapidly quantify infectious enteroviruses polluting the coastal seawaters, a newly developed integrated cell culture and reverse transcription quantitative PCR (ICC-RT-qPCR) assay was used to identify the contamination by enteroviruses in winter seawater samples of Bohai Bay, Tianjin, China. The gene copies of enteroviral 5′UTRs correlated to the initial inoculum numbers across the concentration range of 0.05–500PFUmL⁻¹ (correlation coefficient (R²) was 0.9667). ICC-qPCR revealed that five of seven samples (70.4%) were positive for infectious enteroviruses. The concentration of enteroviruses was estimated at 0.2–21PFUL⁻¹. The result demonstrated that the contamination of enteroviruses in this coastal area may constitute a potential public health risk. This study established a practical assay for widespread monitoring studies of aquatic environments for viral contamination and provided meaningful data for human waterborne viral risk assessment.

The concentrations of heavy metals and organic carbon in sediment of the Homa Lagoon which is one of the most productive lagoons and commercial important active fish trap in the Eastern Aegean Sea, were investigated in order to describe the temporal and spatial distributions of metals. These results were used to evaluate possible ecological risks that could be a problem for the environment of the lagoon in the future. Sediments were enriched with Cr, Ni and considered as heavily polluted per the SQG. The Cf of Ni and Cr were presented moderate level of contamination in this area. The Cd levels indicated moderate degree of contamination at station B, C, D and E due to agricultural drainage water, industrial and domestic wastewater, are transported by the Gediz River. Sediments from Homa Lagoon were most toxic for Ni due to exceedances of the TEL and PEL values.

Polybrominated diphenyl ethers (PBDEs) are now found ubiquitously in the aquatic environment and biota, and there is a growing concern that PBDEs may disrupt endocrine systems, leading to reproductive impairments of aquatic animals. In our study, zebrafish (Danio rerio) were exposed to the 5ng/L, 1μg/L and 50μg/L of DE-71 for the duration of the whole life cycle (120days, from eggs to adults). The expression of selected genes along the brain–pituitary–gonadal (BPG) axis and liver, and the levels of plasma sex hormones were examined. In male fish, up-regulation of GnRH in brain, FSHβ and LHβ in pituitary, FSH-receptor, LH-receptor, and CYP19a in testis was clearly evident, while down-regulation of CYP11a and 3β-HSD was found in testis. In female fish, a 2.4-fold up-regulation of 3β-HSD was found in ovary upon exposure to 50μg/L of DE-71. GnRH in brain, FSHβ and LHβ in pituitary were also up-regulated, while ERβ, TH and TPH in brain and GnRH-receptor in pituitary were significantly down-regulated. Hepatic ERα, AR and VTG in males were all down-regulated, while hepatic ERα and AR in female were up-regulated. Serum estradiol (E₂) was reduced in both male and female upon exposure to DE-71, while significant increases in serum testosterone (T) and 11-keto-testosterone (11-KT) were only found in male but not female fish. The ratio of T/E₂ as well as the ratio of 11-KT/E₂ in male fish increased in a dose-dependent manner upon exposure to DE-71. Our overall results showed that whole life exposure of DE-71 altered the expression of regulatory genes and receptors at all three levels of the BPG axis in zebrafish, and the responses are sex dependent. The observed disruption of GnRH and GtHs can be further related to the subsequent disruption in both levels and balance sex steroid hormones.

The illegal and destructive fishery of date mussels (i.e. the endolithic mollusc Lithophaga lithophaga) reduces the bio-physical complexity of Mediterranean rocky reefs and dramatically impacts biodiversity. Although date-mussel fishermen do not directly impact sea urchins, these echinoids dramatically increase in abundance on rocky reefs impacted by date-mussel fishery (DMF). The recovery of rocky reefs affected by DMF is hampered by the intense unselective grazing of sea urchins on benthic organisms. No evidence is available, however, about the mechanisms that cause the increase in the population density of sea urchins. I demonstrated here that DMF creates a new microhabitat, i.e. the holes left empty after date mussels are extracted, where small-sized sea urchins take refuge and escape predation. This study thus sheds light on a mechanism through which DMF may locally increase sea urchin population density, contributing to maintain the rocks bare on the long term.

The development and broad use of passive acoustic monitoring techniques have the potential to help assessing the large-scale influence of artificial noise on marine organisms and ecosystems. Deep-sea observatories have the potential to play a key role in understanding these recent acoustic changes. LIDO (Listening to the Deep Ocean Environment) is an international project that is allowing the real-time long-term monitoring of marine ambient noise as well as marine mammal sounds at cabled and standalone observatories. Here, we present the overall development of the project and the use of passive acoustic monitoring (PAM) techniques to provide the scientific community with real-time data at large spatial and temporal scales. Special attention is given to the extraction and identification of high frequency cetacean echolocation signals given the relevance of detecting target species, e.g. beaked whales, in mitigation processes, e.g. during military exercises.

This study established wetland microcosms that were either unplanted or planted in monoculture with native mangrove species in Taiwan (Avicennia marina, Rhizophora stylosa, and Lumnitzera racemosa) for the purpose of receiving high-salinity mariculture effluents; additionally, the microcosms operated at different hydraulic retention times (HRTs). Plant growth and the performance of the microcosms with respect to pollutant removal were investigated. The results showed that seedlings of all three mangrove species survived and grew sufficiently well under continuous flooding. The presence of mangroves consistently improved SS, BOD₅, and TP removal, particularly under short HRT conditions. The mangrove microcosms removed pollutants from the mariculture effluents with efficiencies of 5.7–27.1% (SS), 4.9–36.3% (BOD₅), 18.7–29.9% (TP), 21.2–49.8% (NH₄-N), and 5.4–37.7% (NOₓ-N). A. marina and L. racemosa were more tolerant of continuous flooding than R. stylosa. However, no species displayed consistently superior performance in decreasing all pollutant-related parameters investigated. For all pollutants, microcosms operating at a 2-d HRT exhibited a higher removal efficiency than those operating at a 0.5-d HRT.