Contaminated sediments at a pulp mill and former chor-alkali effluent treatment facility in Nova Scotia, Canada will undergo remediation. However, baseline studies assessing contaminants in marine biota in the marine receiving environment are lacking. Historical qualitative and quantitative contaminant data in biota from Boat Harbour (a former tidal lagoon which was used to treat industrial effluent since 1967), and surrounding marine environment were reviewed to establish baseline pollution from industrial effluent and contaminated sediments. Elevated metal, dioxins and furan concentrations previously measured in marine biota needs updating to help inform pre-remediation monitoring. Selection of species, contaminants of concern and sampling locations were ad hoc and often inconsistent with environmental effects monitoring requirements under Canadian federal Pulp and Paper Effluent Regulations. These consolidated baseline data are required to determine historical impacts and to assist future monitoring during Boat Harbour sediment remediation to compare against.

It is hypothesized that pH fluctuations produced by seagrasses metabolism may confer marine calcifiers resistance to ocean acidification. Here, we tested this thesis by comparing the net population growth rate (NPGR) of a foraminifer species (Rosalina sp.) epiphytic of Mediterranean seagrass (Posidonia oceanica) to average current and projected pH scenarios under either stable conditions or diel fluctuations in pH of 0.3 units; variations similar to that experienced in their habitat. No significant differences were found in NPGRs between the fluctuating and stable pH treatments at current pH levels. NPGRs in treatments where pH fluctuated did not present significant differences to the treatment with high and stable pH conditions. In contrast, foraminifers exposed to stable low pH regimes experienced a steep decline in NPGR. These results suggest that diel pH fluctuations generated by P. oceanica photosynthetic activity could confer resistance to ocean acidification to Rosalina sp.

PURPOSE OF REVIEW: Climate warming may bear a penalty on future ozone air quality, even in the absence of changes in anthropogenic activities. This penalty has important implications for policy-making, but its quantification involves complex meteorological, chemical, and biological processes and feedbacks that are not well understood. We examined how climate-sensitive processes may affect surface ozone, identified key knowledge gaps uncovered by recent studies, and summarized latest assessments of the climate change penalty on ozone air quality. RECENT FINDINGS: Recent analyses have challenged earlier paradigms on how climate change may affect surface ozone. The widely accepted associations of high ozone events with stagnation and heat waves require re-examination. Emission responses of natural precursors to climate warming may be significantly modulated by CO₂ levels and ecosystem feedbacks, such that the direction of emission changes cannot be robustly determined at this time. Climate variability may drive fluctuations in surface ozone, which has implications for near-term air quality management. Recent studies have generally projected a climate change penalty on ozone air quality, although the magnitudes are smaller than those projected by earlier studies. This review examined the latest understanding on the climate change penalty to surface ozone. Critical uncertainties are associated with the meteorological, chemical, and biological processes linking climate warming and ozone, and many of the known feedbacks are not yet included in models. Further research is needed to examine those processes in order to better quantify the climate change penalty on surface ozone to inform policy-making.

Current study aimed to evaluate the microplastics abundance in the surface waters of Chabahar Bay for the first time. 21 neuston net water samples were collected from 7 stations. Microplastics were visually counted by stereomicroscope, sorted into 4 size categories, 4 shape categories, and identified by ATR-FTIR spectroscopy. Density of microplastics varied from 0.07 ± 0.03 to 1.14 ± 0.27 with an average density of 0.49 ± 0.43 particle·m−3. Microplastics were mostly found in the shape of fibers. 69% of analyzed particles were polyethylene and polypropylene. Main colors of the collected microplastics were white, blue and red. The results showed that the largest number of microplastics was found at station near populated area. Therefore, it can be concluded that, there is a pressing-need to investigate the distribution of microplastics in sediments and biota of this Bay as well as their effects on marine life and human health.

Concerns are growing about the presence of fluoxetine (FLX) in environmental matrices, as well as its harmful effects on non-target organisms. FLX in aquatic ecosystems has been detected in a range varying from pg/L to ng/L, while adverse effects have been reported in several organisms inhabiting freshwater and marine environments. The present study quantifies FLX concentrations in seawater samples from Santos Bay, Brazil and assesses metabolic responses and sublethal effects on the tropical brown mussel Perna perna. Levels of ethoxyresorufin‑O‑deethylase, dibenzylfluorescein dealkylase, glutathione S-transferase, glutathione peroxidase, cholinesterase, lipoperoxidation, and DNA damage were assessed in the gills and digestive gland of these animals, and lysosomal membrane stability was also assessed in hemocytes. FLX altered phase I and II enzyme activities, caused cytogenotoxic effects, and negatively impacted the overall health of mussels exposed to environmentally relevant concentrations. These findings contribute to characterize the risks of introducing this drug into the marine environment.

The heavy metals (Cu, Cr, Zn, Cd, Pb) were analysed for 217 surface sediment samples collected across 14 typical intertidal zone areas in China. The data reveals the heavy metals spatial distribution patterns and correlations among their concentrations. Cu, Zn, Cd and Cr showed similar trends of spatial variation and the correlations between the concentrations of every two heavy metals were significantly positive except for the correlation between Pb and Cr concentrations. By using Nemerow index method, Enrichment factor and Sediment Quality Guidelines, it is found that Hangzhou Bay and Jiulong River Estuary were polluted, Yingluo Bay and Dongzhaigang Bay were Cd-rich areas. Except Beidaihe shoal, Sishili Bay and Yingluo Bay that were not exposed to any ecological risk of heavy metals and had no adverse biotoxic effects, the other 11 typical intertidal zone areas were exposed to moderate ecological risk of heavy metals in the sediment with potential adverse biotoxic effects.

The aim of this study was to analyze different port areas (leased, nonleased and vessels) in terms of plastic segregation (scenario 1) and how much of this plastic is recycled (scenario 2). Data envelopment analysis was applied and the variables were total amount of solid waste and percentage of segregated plastic in relation to total solid waste (scenario 1) and amount of segregated plastics and percentage of recycled in relation to segregated plastics (scenario 2). Segregation efficiency was low (49%) in the nonleased area, but all the segregated material is recycled, suggesting that the management bottleneck in this case is waste segregation. Similar segregation results were obtained in the leased areas and vessels (36 and 35%, respectively), but recycling efficiency was greater in the former (92 and 24%, respectively).

Planktonic sea-urchin larvae actively ingest polyethylene microplastics (MP) that accumulate in the larval stomach and can be distinguished from natural food using polarized light microscopy. MP filtering rates were similar to those of natural particles (microalgae) of the same size range; 0.30 to 0.35 mL min⁻¹. However, the ingestion of MP did not increase the toxicity of a hydrophobic organic chemical, the 4‑n‑nonylphenol (NP), either in microalgae-fed or starved larvae. The 48 h EC₅₀ of NP was more than two fold higher in fed (158.8 to 190.9 μg L⁻¹) compared to starved larvae (64.3 to 83.7 μg L⁻¹), disregarding the presence and amount of MP, which did not significantly affect larval growth. Therefore, MP did not act as vectors of a hydrophobic chemical such as NP to these planktonic organisms. These results challenge the hypothetical role of MP as vectors of organic contaminants to marine food webs.

Microplastic particles (<5 mm), which are an emerging threat, are commonly found in marine ecosystems worldwide. This study investigated the effect of different types of coastal land use on microplastic frequency and distribution on the coastline of Bandar Abbas city; this study used a large sample compared to that used in other studies conducted in this region. The average number of microplastics was determined as 3252 ± 2766 microplastics/m² (±SD). ATR FT-IR spectroscopy showed that the dominant microplastic particles are expanded polystyrene, polyethylene terephthalate, polypropylene, and polyethylene. Statistical analysis showed a significant difference in microplastic contamination levels between the urban and nonuse beaches. This shows that heavily urbanized areas and human activities have significant effects on the dispersion and frequency of microplastics in the coastal areas of Bandar Abbas. Periodical coast-based cleanup and studies on microplastic pollution and their fluxes by comprehensive sampling are mostly recommended for the Persian Gulf coastline.

In situ studies of plastic deterioration can help us understand the longevity of macroplastic as well as the generation of microplastics in the environment. Photo-oxidation contributing to the generation of microplastics in the marine environment was explored using four types of plastic (polyethene, polystyrene, poly(ethylene terephthalate) and Biothene® exposed in light and in shade, in both air and sea water. Metrics for deterioration were tensile extensibility and oxidation rate. Measurements were conducted at intervals between 7 and 600 days' exposure. Deterioration was faster in air than in sea water and was further accelerated in direct light compared to shade. Extensibility and oxidation were significantly inversely correlated in samples exposed in air. Samples in sea water lost extensibility at a slower rate. Polystyrene, which enters the waste stream rapidly due to its wide application in packaging, deteriorated fastest and is, therefore, likely to form microplastics more rapidly than other materials, especially when exposed to high levels of irradiation, for example when stranded on the shore.