Frequencies of eight nuclear abnormalities (NAs) reflecting environmental genotoxicity and cytotoxicity, were examined in 739 specimens of herring (Clupea harengus), flounder (Platichthys flesus) and cod (Gadus morhua) collected between 2009 and 2017 at 50 study stations located in the Gulf of Gdansk and the southern part of the Gdansk Deep (the Baltic Sea). The highest levels of geno-cytotoxicity were recorded in fish caught at stations located in close proximity to chemical and conventional munitions dumping sites or in zones polluted by Chemical Warfare Agents (CWAs). The values of NAs were significantly higher (up to 51-fold compared with the reference level) in herring caught at seven stations and in cod from one station located close to the munitions dumping sites. Exceptionally high total genotoxicity (∑Gtox) risk was found for flounder collected from 18 (72.0%) stations, herring caught at 12 (38.7%) stations and cod caught at four (17.4%) studied stations.

The impact of boat related noise on marine life is a subject of concern, particularly for fish species that utilize acoustic communication for spawning purposes. The goal of this study was to quantify and examine the risk of boat noise on fish acoustic communication by performing acoustic monitoring of the May River, South Carolina (USA) from February to November 2013 using DSG-Ocean recorders. The number of boats detected increased from the source to the mouth with the highest detections near the Intracoastal Waterway (ICW). Boat noise frequency ranges overlapped with courtship sounds of silver perch (Bairdiella chrysoura), black drum (Pogonias cromis), oyster toadfish (Opsanus tau), spotted seatrout (Cynoscion nebulosus), and red drum (Sciaenops ocellatus). In the May River estuary, red drum may experience the greatest risk of auditory masking because of late afternoon choruses (21% time overlap with boat noise) and only one spawning location near the noisy ICW.

Pollution has led to a decline of benthic invertebrate biodiversity of Narragansett Bay, raising questions about effects on ecosystem functions and services including shellfish production, energy flow to fishes, and biogeochemical cycles. Changes in community composition and taxonomic distinctness (biodiversity) were calculated from the 1950s—when quantitative benthic invertebrate data first became available—to 2015. Change in community composition of the bay was correlated with changes in dissolved inorganic nitrogen, dissolved oxygen, and sediment contaminants. A mid-bay reference site showed moderate changes in community composition but no change in biodiversity. In contrast, a more impacted site in the upper bay showed substantial differences in community composition over time and a decline in taxonomic distinctness. Bay-wide, as inputs of some stressors such as nutrients and sediment contaminants have declined, there are signs of recovery of benthic biodiversity but other stressors such as temperature and watershed development are increasing.

This study's objectives were to evaluate the elements degree of contamination in the Tajan River and the status of contamination in this river for future ecotoxicology studies. Based on geo-accumulation index (Igₑₒ) and contamination factor (CF) indices, Cr, Mn, Fe, Ci, Ni and Zn showed low contamination levels at all stations, while Se showed a very high degree of contamination. Potential ecological risk factor (Eᵣⁱ) and risk index (RI) indices values showed low ecological risk for the river, and this was confirmed by the pollution load index (PLI) results as well as a comparison of the concentrations of these elements with the mean values of the earth's crust and sediments worldwide. Overall, the results showed that the river cannot be regarded as a contaminated river with respect to the elements studied (with the exception of selenium and arsenic) for ecotoxicology studies, but can be considered a reference river.

In this study, the activity concentrations of ²¹⁰Po and ²¹⁰Pb were determined in different types of bivalve molluscs sampled during the period of May 2014–June 2015 along the Andalusian littoral. Radioactivity concentrations of ²¹⁰Po were determined through alpha-particle spectrometry using ²⁰⁹Po as an internal tracer. Radioactivity concentrations of ²¹⁰Pb were determined through low-level gamma-ray spectrometry. The activity concentrations of ²¹⁰Po and ²¹⁰Pb varied between 40 ± 2 and 515 ± 9 Bq kg⁻¹ dry weight (d.w.), and ND (lower than limit of detection) and 73 ± 10 Bq kg⁻¹ d.w., respectively. The committed effective dose to humans was calculated to range from 39 to 477 μSv year⁻¹. Radioactivity and dose levels were compared with previous studies from other countries.

Acid-volatile sulfides (AVS) formation and its role on trace metals bioavailability were studied in semi-arid mangroves. The semi-arid climatic conditions at the studied sites, marked by low rainfall and high evapotranspiration rates, clearly limited the AVS formation (AVS contents varied from 0.10 to 2.34μmolg−1) by favoring oxic conditions (Eh>+350mV). The AVS contents were strongly correlated with reactive iron and organic carbon (r=0.84; r=0.83 respectively), evidencing their dominant role for AVS formation under semi-arid conditions. On the other hand, the recorded ΣSEM/AVS values remained >1 evidencing a little control of AVS over the bioavailability of trace metals and, thus, its minor role as a sink for toxic metals.

The presence of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli in oceanic ecosystems constitutes an emerging public health risks in the marine environment. In this study, we report for the first time the identification of ESBL (CTX-M)-producing E. coli in wild fishes from a polluted area in the South Atlantic coast of Brazil, where a genomic analysis confirm the presence of livestock and human E. coli lineages belonging to sequence types (STs) ST744 and ST746, which carried clinically relevant resistance genes for human and veterinary antibiotics, and heavy metals. These findings reveal the presence of multidrug-resistant (MDR) bacteria in the gut microbiota of wild fishes living in polluted coastal waters, alerting that microbial contamination by bacteria related directly and indirectly to human or animal activities could affect the safety of the seafood supply, as well as the commercial and recreational use of coastal marine waters.

Statistical analysis of rainfall data from 2005 to 2015 showed that atmospheric deposition supplied large amount of dissolved inorganic nitrogen (38–155 mg·m−2·month−1) in N-deficient South China Sea and Eastern Indian Ocean. To understand marine ecosystem responses to increasing nutrient disturbances, we implemented field mesocosm experiments to study phytoplankton community structure and biodiversity responses to nutrient treatments with nitrate, phosphate and iron across tropical seas. Our results showed that DIN supply would change phytoplankton community structure and stimulated the regime shift from cyanobacteria to diatoms (relative dominance R > 0). Phytoplankton communities were dominated by diatoms (relative abundance >50%) accompanied by high chlorophyll a content with 1.58–39.27 μg·L−1 in DIN-added cultures, whereas cyanobacteria dominated communities (relative abundance >60%) with low biomass of 0.12–0.18 μg·L−1 in undisturbed cultures. Simultaneously increased DIN loading from atmospheric deposition would decrease ecological diversity of tropical seas owing to species competition and succession (Shannon diversity H′ decreased to <1).

Cape monkfish (Lophius vomerinus) is one of the long-lived species and top predators in the northern Benguela region. Studies on bioaccumulation of mercury (Hg) in cape monkfish are limited. This study compared the total Hg concentration between monkfish muscle and liver tissue; and related the monkfish total Hg concentrations to fish body size and capture locations (depth and latitude). Monkfish specimens (n = 529) were collected from 2016 to 2018. The mean total Hg concentration was 0.126 ± 0.005 mg/kg in muscle tissues and 0.106 ± 0.005 mg/kg in liver tissues. No significant differences were observed between total Hg concentrations of muscles and liver tissues. Differences in Hg concentrations between monkfish length classes were observed. No significant correlation was found between total Hg concentrations and latitude. A significant increase of total Hg concentration with the depth was observed. The concentrations of Hg were below the World Health Organization (WHO limits for fish (0.5 mg/kg).