Wastewater treatment plant effluent introduces a mixture of pollutants into marine environments; however, the impacts of chronic sublethal exposures on populations are often unclear. Presence of estrogenic agents in sediments and uptake of these compounds by demersal flatfishes has been reported at the Orange County Sanitation District (OCSD) wastewater outfall. Furthermore, estrogenic activity has been identified in male flatfish in the area, potentially contributing to observed population declines in the OCSD region. Rising ocean temperatures may further contribute to flatfish declines as relationships between temperature and abundance have been reported in the Southern California Bight. To investigate declines, sex ratios, condition factor, organ health indices, hormones, and vitellogenin were quantified in flatfish collected at OCSD outfall and reference sites. Additionally, historical temperature data was examined for trends with population abundances. Rather than being linked to estrogenic activity, results indicated that population declines were more correlated to increases in ocean temperature.

This work is the first study on the spatial and temporal distribution of metals in zooplankton collected along the Persian Gulf. The rank order distribution of metals in terms of their overall average concentration in the zooplankton was observed to be Fe > Zn > Cu > Cd > Ni > Cr > Pb > Co > V. No clear pattern and no statistical differences were detected among the areas and the sampling stations. The highest concentrations of Cu, Zn, and Pb were observed in summer while the highest concentration levels of Fe and Ni were observed in winter. The highest mean zooplankton metal concentration level was found to be Fe with 10.42 μg/g (in winter) and the lowest levels were for V (in spring and summer) and Co (in winter), both of which had a level of 0.01 μg/g. The results can be used to establish base-line data for the trace metal content of zooplankton in the northern region of the Persian Gulf.

A mass balance of total mercury (HgT, dissolved+particulate) is constructed for China's Jiulong River estuary based on measured HgT concentrations in the surface water, sediment, porewater, and groundwater for May, August, and November 2009, combined with data from the literature. The HgT mass budget results show that the dominant source (39–55%) is desulfurized seawater discharged from the Songyu coal-fired power plant. Submarine groundwater discharge (SGD)-derived HgT flux into the estuary is equivalent to 8–58% of the HgT input from the Jiulong River, which is remarkable when compared with SGD-derived HgT fluxes reported in coastal systems worldwide. Hence, SGD is a significant pathway for the transport of HgT into the Jiulong River estuary. The primary HgT sinks is export to the Taiwan Strait (53–88%), which has important environmental implications on the Hg cycling and marine ecosystems in marginal seas.

In aquatic environments, Cd contamination is a great concern because this non-essential metal presents risks both for wildlife and human health. Data about the concentration and transfer of Cd in Patagonian and Antarctic aquatic food webs are crucial for assessing the impacts of this element in pristine ecosystems. Consequently, the concentration of Cd was measured in thirty-two species collected in the 2014 austral summer from two locations of the Western Patagonia and two locations of the Antarctic Peninsula. The main objective of this work was to assess the relationship between Cd concentration and trophic level determined by δ15N. In the studied trophic positions, Cd showed a positive relationship between concentration and trophic level, which suggests biomagnification of this element in macroinvertebrates. However, there was a significant dilution when higher trophic organisms were considered.

Coral communities are found at high latitude on the East Coast subtropical reefs of South Africa. They are biodiverse, economically important, and afforded World Heritage Site status in the iSimangaliso Wetland Park where some are subjected to recreational use. While the Park's unique coral reefs have, to date, suffered little bleaching from climate change, they are susceptible to the phenomenon and provide a natural laboratory for the study of its effects at high latitude. This review covers recent advances in the regional oceanography; coral community dynamics and the underpinning reef processes, including minor bleaching events; the incidence of coral disease; and coral genetic connectivity. The effects of human activity (SCUBA diving, recreational fishing, pesticide use) were assessed, as well as the nursery benefits of Acropora austera, a coral which provides the reefs with much structure and is vulnerable to damage and climate change. The reefs were valued in terms of human use as well as services such as sediment generation and retention. The results have provided valuable information on relatively pristine, high-latitude reefs, their socio-economic benefits, and the anticipated effects of climate change.

In this study, we carried out grain size and heavy metal analyses and also assessed heavy metal enrichment and ecological risk indices in ten sediment samples collected by the manned submersible Jiaolong at different segments of the Yap Trench. The results showed that the sediments in the Yap Trench were mainly slumping deposits composed of sandy silt. Heavy metals in the sediments showed different spatial distribution patterns from north to south direction of the trench. The distribution pattern of these heavy metals also differed in the eastern and western flanks of the trench. From the results of the enrichment factors, only arsenic, chromium, and manganese showed a slight enrichment. However, all elements were affected by natural factors. Further, most elements showed a low ecological risk, and only arsenic showed a moderate risk at two stations. Finally, the potential ecological risk of the whole study area was at a low level.

Acoustic deterrent devices (ADDs) are used in attempts to mitigate pinniped depredation on aquaculture sites through the emission of loud and pervasive noise. This study quantified spatio-temporal changes in underwater ADD noise detections along western Scotland over 11 years. Acoustic point data (‘listening events’) collected during cetacean line-transect surveys were used to map ADD presence between 2006 and 2016. A total of 19,601 listening events occurred along the Scottish west coast, and ADD presence was recorded during 1371 listening events. Results indicated a steady increase in ADD detections from 2006 (0.05%) to 2016 (6.8%), with the highest number of detections in 2013 (12.6%), as well as substantial geographic expansion. This study demonstrates that ADDs are a significant and chronic source of underwater noise on the Scottish west coast with potential adverse impacts on target (pinniped) and non-target (e.g. cetaceans) species, which requires further study and improved monitoring and regulatory strategies.

The aim of the present study was to evaluate the sorption and desorption of sulfamethoxazole (SMX), propranolol (PRP) and sertraline (SER) by polyethylene (PE) microplastics in water. After the 96 h mixture, the sorption percentages of pharmaceuticals on PE microplastics decreased according to the following order: SER (28.61%) > PRP (21.61%) > SMX (15.31%). The sorption kinetics were fitted well with the pseudo-second-order model. Both linear and Freundlich models were able to describe the sorption isotherm. The results suggest that the sorption process of the pharmaceuticals may be adequately described by their hydrophobicity and electrostatic interactions. The desorption results showed that 8% and 4% of PRP and SER, respectively, were released from the microplastics within 48 h, but the sorption of SMX was irreversible. The results indicate the potential risks of PRP and SER for bioaccumulation in aquatic organisms via ingestion of the microplastics in aquatic environments.

Microplastics and synthetic musks (SMs) are two typical organic pollutants in the marine environment. In this study, the sorption of three SMs to microplastics in a simulated seawater environment was examined. Tonalide (AHTN), musk xylene (MX), and musk ketone (MK) were the musks investigated, while polypropylene (PP) was used as the microplastic. It was found that the equilibrium sorption time was about 10h and the adsorption kinetics model conformed to a Lagergren adsorption model. The adsorption capacity increased with decreasing particle size. Adsorption reached a peak at 25°C, and the adsorption capacity was not sensitive to the concentration of sodium chloride. There is a need for more research and monitoring of microplastics in the marine environment due to their strong ability to absorb organic pollutants.

National and international regulations require that ships' ballast water is treated to minimize the risk of introducing potentially invasive species. A common approach employed by commercial ballast water management systems is chlorination. This study presents the algal toxicity findings for three chlorination-based BWMS and their implications to environmental safety of port waters receiving treated ballast water from ships. Discharged treated ballast water from all three BWMS was toxic to algae with IC25s (25% growth inhibition) ranging from 9.9% to 17.9%, despite having total residual oxidant concentrations below 0.02 mg/l, based on Whole Effluent Toxicity assays. When held at 4 °C, some of the ballast water samples continued to exhibit toxic effects with no observed effect concentrations as low as 18% after a 134 day holding time. Thirteen individual disinfection by-products were measured above the detected limit at the time of discharge. No correlation between DBPs and algal toxicity was observed.