Inorganic arsenic (As) is one of the most toxic pollutants in the water. We have studied their effects on the marine teleost European sea bass (Dicentrarchus labrax) at 2 and 10 days of 5 μM of As2O3 (sub-lethal doses) waterborne exposure. Arsenic accumulates in liver and gill tissues. The expression profile of five genes (bax, blc2, casp3, casp8 and casp9) involved in apoptosis cell death confirmed apoptotic effects in liver, slight changes in gill and no effects in skin according with the histopathology findings. Total IgM level and peroxidase activities were increased at 2 and 10 days, respectively. The bactericidal activity was decreased at 2 days after As exposure. A general decrease of cellular immune activities with significant differences in the case of respiratory burst activity was observed after 2 and 10 days of exposure. This work describes for the first time the effects of As exposure on European sea bass.

The increasing availability of human-made structure in the oceans coupled with climate changes may lead to the range expansion of species able to disperse by rafting. In this study, we report on zoantharian species of genera Isaurus, Palythoa, Umimayanthus and Zoanthus covering artificial substrates in locations in both the Atlantic and Pacific oceans. Moreover, we reviewed observations of additional zoantharians as macrofouling organisms, and discuss the possible role of rafting in the dispersal of this cosmopolitan group. Traits reported to some zoantharian species, such as hermaphroditism and resistance to desiccation, support their dispersal potential by drifting attached to floating objects. Further reports of zoantharian species covering floating artificial structures and natural debris are needed to increase our knowledge of dispersal mechanisms in the oceans. Additionally, this information is essential to monitor and manage possible exotic species invasions, especially for zoantharian species that are common in the aquarium trade.

Constructed coastal marsh regulates land-born nitrogen (N) loadings through salinity-dependent microbial N transformation processes. A hypothesis that salinity predominantly controls N removal in marsh was tested through incubation in a closed system with added-15NH4+ using sediments collected from five sub-marshes in Shihwa marsh, Korea. Time-course patterns of concentrations and 15N–atom% of soil-N pools were analyzed. Sediments having higher salinity and lower soil organic-C and acid-extractable organic-N exhibited slower rates of N mineralization and immobilization, nitrification, and denitrification. Rates of denitrification were not predicted well by sediment salinity but by its organic-C, indicating heterotrophic denitrification. Denitrification dominated N-loss from this marsh, and nitrogen removal capacity of this marsh was estimated at 337 kg N day−1 (9.9% of the daily N-loadings) considering the current rooting depth of common reeds (1.0 m). We showed that sediment N removal decreases with increasing salinity and can increase with increasing organic-C for heterotrophic denitrification.

We investigated the relationship between the AMBI index and different contamination proxies in an urbanized bay in South America (SE Brazil), and the effect of (a) abundance data transformation and (b) exclusion of low-reliability sites (high SD; low N) on the index' performance. Poor ecological quality and opportunistic species were related to an increase in contaminants concentrations and mud content. Good ecological status and sensitive species (EG I) were mainly related to increased hydrodynamics. Data transformation caused minimal changes to the overall relationships, but exclusion of low-reliability sites improved the relationship between ecological groups and contamination proxies. Our results show that AMBI is robust in detecting effects of different contaminants in the area and reinforce the importance of the index as a tool for coastal management, but local joint efforts are needed to improve and adjust local species classification in ecological groups to improve the index' performance.

The objective of this study is to propose the use of specific synthetic lipid as an active substance (biocide) in the control of harmful aquatic microorganisms, such as pathogens and non-indigenous species, transported in ships' ballast water. The biocide candidate, without metal or halogen components, was produced from a sub-product of the edible oil industry, the lecithin. Laboratory assays were conducted with phytoplankton, zooplankton, and marine bacteria to evaluate the efficiency of the biocide. The study also considers specific biocide's characteristics related to environmental risks, such as chemical composition, persistence, bioaccumulation, and toxicity. Results showed that, in the first 24 h of treatment, the biocide effectively reduced the concentration of the planktonic micro-organisms to very low levels. Additionally, a preliminary risk evaluation pointed that biocide candidate has a low residual toxicity, also a low potential for persistence and bioaccumulation in the environment.

The goal of the present study was to verify the suitability of using melanomacrophage centres (MMCs) as response biomarkers of marine pollution in European anchovy, which are short-lived, migratory, small pelagic fish. This suitability was verified by analysing the MMC density and cytochrome P450 monooxygenase 1A (CYP1A) expression in livers of anchovies from four areas of southern Italy. Age 2 anchovies sampled from three areas exposed to pollutants of industrial/agricultural origin (Gulf of Gela, Mazara del Vallo and Gulf of Naples) showed liver areas occupied by MMCs and numbers of MMCs that were significantly higher than those in the anchovies from Pozzallo, which is a marine area not subjected to any source of pollution. Anti-CYP1A immunoreactivity was observed in the hepatocytes of all specimens sampled from the Gulf of Gela. These findings suggest the utility of liver MMCs as biomarkers of exposure to pollutants in this small pelagic fish.

This body of work demonstrated the levels of selected contaminants (as well as their potential sources), in mussels (Mytella guyanensis) - a known bio-indicator of pollution, along the west coast (Gulf-of-Paria) of Trinidad. The findings demonstrated that polyaromatic hydrocarbons levels in the mussels investigated were moderate to high (201.80–1200.08 μg/kg). Notably, benzo(a)pyrene levels (1.15–9.32 μg/kg) exceeded the European Union guidelines at various sites. The distribution of PAHs and trace elements in the Gulf of Paria are impacted by tidal currents and local source discharge. Significant risks were identified from toxic carcinogenic equivalent levels (3.01 to 22.37 μg/kg) and mutagenic equivalent levels (3.98 to 38.61 μg/kg). The concentration of trace elements, Zn (46.05–56.36 mg/kg) and Cd (0.46–1.17 mg/kg), exceeded both local and international guidelines at certain sites investigated. The analysis revealed a high bioavailability of the identified pollutants in the Gulf of Paria from industrial, urban and marine activities.

Natural radioactivity in the beach sand and soil was measured and evaluated in typical ecosystems of mangroves, seagrasses, and coral reefs along the coastline of Guangxi Province, China. Radioactivity in the soil was about three times higher than that in the beach sand probably due to the distinct mineral components and particle sizes. A comparison with natural radioactivity levels in the global beach sands indicated that the beach sand of Guangxi had the lowest radioactivity. Radiological parameters including radium equivalent activity (Raeq), external and internal hazard indices (Hex and Hin), representative gamma level index (Iγr), absorbed gamma dose rate (DR), and annual effective dose equivalent (AEDE) were lower than the recommended values. Our results provide baseline data on radioactivity in the beach sand and soil along the coastline of Guangxi and contribute to the database of radioactivity in the global beach sand.

This study was conducted to investigate the median lethal concentration (LC50) of copper pyrithione (CuPT) at 96-hr exposure on adult Javanese medaka (Oryzias javanicus) in revealing toxicological effects of CuPT contamination in the tropical area. Wild stock fishes were acclimatized for 14-days prior analysis. Triplicate of test tanks for seven test concentrations were placed with ten fishes each, this includes two control tanks. The behaviour of the tested fishes was manually observed through a camera. The LC50 of CuPT at 96-h was found to be 16.58mg/L. Tested fishes swam slowly in vertical movement and swam fast towards food during feeding time as the sign of stress behaviour. Meanwhile, fishes in the two control groups swam actively in a horizontal manner and no excitement during feeding time. No mortality in control groups. Results indicate CuPT to be toxic to Javanese medaka at low concentration and caused behavioural stress.

This study focuses on creating a baseline for ⁴⁰K, ²¹⁰Pb, ¹³⁷Cs, ⁹⁰Sr, ²²⁶Ra, ²²⁸Ra, ²³⁸U, ²³⁵U, ²³⁴U, ²³⁹⁺²⁴⁰Pu and ²³⁸Pu in marine sediments in the northwestern Gulf. The respective measured concentration ranges were 386–489, 32.3–48.8, 1.5–2.9, 4.53–5.42, 18.3–23.1, 18.8–23.0, 22.3–30.5, 0.99–1.33, 25.6–34.8, 0.30–0.93, and 0.0008–0.00018Bqkg⁻¹. The levels of these radionuclides are generally comparable to values reported for other marine waters in the northern hemisphere. The ¹³⁷Cs activity in the Gulf sediments offshore Kuwait is an order of magnitude lower compared to sediments from northeastern Iran. Other than that finding, no hot spots were observed in sediments adjacent to power and desalination plants, oil and gas industrial activities or wastewater treatment facilities. These data will serve as a baseline to gauge possible future inputs of radionuclides in the northern Gulf. The calculated average ratio of ²³⁵U/²³⁸U activity in the area is in agreement with the reported figure of the natural uranium ratio, suggesting the absence of depleted uranium (DU) at all the stations. The low concentration of ²³⁹⁺²⁴⁰Pu suggests that there is no significant source of plutonium except that from atmospheric fallout from weapon testing and possible dry deposition via long-range dust transport.