Copper can be beneficial or harmful to coral at environmentally relevant levels, making environmental monitoring a challenging. Membrane lipids make the cell a dynamic environment according to the circumstances; thus, the lipid profile should be indicative of an environmental/physiological state. To gain more insight into the copper effect on coral health and be a basis of biomonitoring, glycerophosphocholine profiling of coral exposed to microenriched copper levels was conducted in this study. The copper microenrichments resulted in a diacritical effect of decreasing carbonic anhydrase activity, following a supplementation effect, on coral lipid metabolism. Microdifferences in copper levels are critical to determine the coral metabolic state and were therefore included in this study. In addition, an excellent quantitative model correlating the coral lipid variation with the exposed copper levels or the induced physiological effect was obtained to demonstrate its performance for biomonitoring.

This study assessed the concentrations of nine trace metals from juvenile C. falciformis caught from Indian Ocean. This study also discussed the metal pollution index (MPI) and bioconcentration factor (BCF) of each element, and their correlations. Further, the potential health risks of consuming shark muscles (THI) were evaluated. Results showed the mean concentrations of 9 elements as follows: Cu (0.36 ± 0.17), Zn (5.19 ± 16.6), Pb (0.12 ± 0.23), Cd (0.17 ± 0.21), Cr (0.57 ± 1.61), Ni (0.086 ± 0.51), As (1.36 ± 0.83), Co (0.000073 ± 0.0074), and V (0.0024 ± 0.0094) mg/kg ww. The BCF values of the elements were higher than 1, with Co and V being the lowest indicating their bioaccumulative behavior. Correlation analysis showed MPI to be highly correlated with Cu, indicating its greater contributions to the total pollution load. Principal components analysis explained 81.0% of the variability in biometric characteristics and metal concentrations. Health risk assessment for consuming shark muscle in Taiwanese male and female adults suggests potential chronic non-carcinogenic health hazards.

Ocean acidification has emerged as a major concern in the last fifteen years and studies on the impacts of seawater acidification on marine organisms have multiplied accordingly. This review aimed at synthesizing the literature on the effects of seawater acidification on tropical scleractinians under laboratory-controlled conditions. We identified 141 articles (published between 1999 and 2021) and separated endpoints into 22 biological categories to identify global trends for mitigation and gaps in knowledge and research priorities for future investigators. The relative number of affected endpoints increased with pH intensity (particularly for endpoints associated to calcification and reproduction). When exposed to pH 7.6–7.8 (compared to higher pH), 49% of endpoints were affected. The diversity in experimental designs prevented deciphering the modulating role of coral life stages, genera or duration of exposure. Finally, important bias in research efforts included most experiments on adult corals (68.5%), in 27 out of 150 (18%) coral ecoregions and exclusively from shallow-waters.

Mitigating and preventing beach litter from entering the ocean is urgently required. Monitoring beach litter solely through human effort is cumbersome, with respect to both time and cost. To address this problem, an artificial intelligence technique that can automatically identify different-sized beach litter is proposed. The technique was established by training a deep learning model that enables pixel-wise classification (semantic segmentation) using beach images taken by an observer on the beach. Eight segmentation classes that include two beach litter classes were defined, and the results were qualitatively and quantitatively verified. Segmentation performance was adequately high based on three metrics: Intersection over Union (IoU), precision, and recall, although there is room for further improvement. The potency of the method was demonstrated when it was applied to images taken in different places from training data images, and the coverage of artificial litter calculated and discussed using drone images provided ground truth.

Floating marine litter (FML) surveys were conducted in the near shore waters of Mombasa, Kilifi and Kwale Counties of Kenya through trawling using a manta net. A mean density of 26,665 ± 2869 items km⁻² composed of 34.8% hard plastic, 40.5% soft plastics and 22.0% plastic lines/fibers was reported in this study. Litter densities in Kwale, Kilifi and Mombasa Counties were not influenced by monsoons, however, litter composition was influenced by monsoons with NEM and SEM being dominated mainly by hard plastics and soft plastics respectively. Litter categories diversity, evenness and richness were also not influenced by the monsoons during both NEM (1.01, 0.78 and 3, respectively) and SEM (1.09, 0.78 and 4, respectively). Fishing and recreational beaches had higher litter densities during NEM compared to SEM attributed to higher beach visitation and increased fishing activities during the calmer NEM season.

The purposes of this study were to measure the concentrations of arsenic speciation in shellfish from South China Sea and evaluate the health risk by local residents through shellfish consumption. The median concentrations (in wet weight) of arsenic speciation in shellfish samples were in the following order: AsB (16.0 mg·kg⁻¹) > DMA (1.30 mg·kg⁻¹) > AsV (0.23 mg·kg⁻¹) > AsC (0.08 mg·kg⁻¹) > AsIII (0.05 mg·kg⁻¹) > MMA (0.01 mg·kg⁻¹). Among shellfish species, Mactra mera and Babylonia areolata were found to accumulate iAs and AsB, respectively. The target hazard quotient values of iAs (THQᵢAₛ) in all shellfish samples were lower than 1. However, the carcinogenic risk values of iAs (CRᵢAₛ) in the Mactra mera, Mytilus galloprovincialis and Pinctada margaritifera were beyond the acceptable range, implying that continuous exposure to iAs pollution via the consumption of these shellfish would pose a potential cancer risk to local consumers.

Mangrove forests have been reported as sinks for metals because of the immobilization of these elements in their soils. However, climate change may alter the functioning of these ecosystems. We aimed to assess the geochemical dynamics of Mn, Cu, and Zn in the soils of a mangrove forest dead by an extreme weather event in southeastern Brazil. Soil samples were collected from dead and live mangroves adjacent to each other. The physicochemical parameters (total organic carbon, redox potential, and pH), total metal content, particle size, and metal partitioning were determined. Distinct changes in the soil geochemical environment (establishment of suboxic conditions) and a considerable loss of fine particles was caused by the death of the mangroves. Our results also showed a loss of up to 93 % of metals from soil. This study highlights the paradoxical role of mangroves as potential metal sources in the face of climate change.

Seventy-four surface sediment samples were collected from the Arctic Ocean and Bering Sea to determine the content of metal(loid)s (As, Cu, Cd, Ni, Pb, Zn and Cr). Metal(loid)s content in these sediments varied from 2.36–41.90 mg/kg for As, 8.63–82.28 mg/kg for Cu, 0.14–0.71 mg/kg for Cd, 11.86–100.60 mg/kg for Ni, 8.30–27.58 mg/kg for Pb, 39.93–391.43 mg/kg for Zn, and 40.96–106.49 mg/kg for Cr. The pH and water-soluble organic carbon content had considerable impacts on the content of metal(loid)s in sediment, but the texture of sediment has limited influence on metal(loid)s content in sediment. In addition, the hotspots of most of these metal(loid)s appeared in the Beaufort Sea region. The geoaccumulation index (Igₑₒ) indicated that Cd was the metal with the highest contamination in these sediments, with 55.41% of the sample sites posing moderate pollution. The ecological risk for As, Cu, Ni, Pb, Zn and Cr indicates low ecological risk (100%), while Cd posed moderate risk (35.14%), considerable risk (54.05%) and high risk (10.81%) and attributed more than 76.45% of the total potential ecological risk of these metal(loid)s.

Marine litter is recognised as imposing a range of costs on marine economies and environments as we target UN Sustainable Development Goals (SDGs) to 2030. Prevention of these avoidable damage costs can restore economic benefits and ocean health. In the Asia-Pacific we estimate the annual damage cost from marine litter to the marine economy has risen eightfold since 2008 and in 2015 was US$10.8 billion (bn), translating to $18.3bn globally ($21.3bn in 2020). In 2020 the present value of global economic damage costs to 2030 and 2050 are $−197bn and $−434bn respectively and as high as $−229bn and $−731bn, if predicted increased plastic production eventuates. As avoidable costs, these projections are the unacceptable “cost of global inaction” in today's terms. Litter prevention by government, industries and the community is needed now, to reduce these predicted marine economic cost impacts to 2050 with environmental benefits.

A quantification of total mercury (Hgₜₒₜ) and methylmercury (MeHg) concentrations in sediment and mussels was carried out in the east basin of the Orbetello lagoon in order to assess their bioaccumulation potential. The sediment was sampled in four macroareas, mussels were transplanted in the same sites and collected after seven weeks. The results show that Hgₜₒₜ concentrations in sediments exceeded (0.21–16.9 mg/kg dry weight (dw)) the environmental quality standard of the Italian legislation (0.3 mg/kg dw). The Hgₜₒₜ concentration in mussels (0.050–0.324 mg/kg wet weight (ww)) does not exceed the limit values (0.5 mg/kg ww) of the European food legislation. The biota–sediment accumulation factors (BSAFs) derived for MeHg (80–306.7) and a biomagnification factor (BMF) greater than 1 for Hgₜₒₜ demonstrate that in the lagoon, these compounds can be transferred in the upper levels of the trophic chain and pose a risk to human health.