Laguncularia racemosa and Sonneratia apetala are fast-growing exotic mangrove species in Southern China and widely used for afforestation. However, the invasiveness of the two exotic species is still unclear. We compared structural and physiological traits and energy-use related traits between L. racemosa and S. apetala, and with two natives (Kandelia obovata and Aegiceras corniculatum) in northern Fujian. Results showed that leaf construction cost based on mass (CCM) and caloric values of L. racemosa were significantly lower than S. apetala, and the two natives had highest CCM. Because lower CCM, L. racemosa grew faster with a taller height (4.83 m) and wider ground diameter circumference (40.03 cm) than S. apetala (4.43 m tall and 35.63 cm wide) and the two natives (2.42 m tall and 26.78 cm wide). These findings indicated that L. racemosa could be more invasive than S. apetala in mangrove forests in northern Fujian, China where it still grew well, which deserves more attention.

Determining the overall effects of human activities on the estuaries, seas and coasts, as a precursor to marine management, requires quantifying three aspects. These are: (a) the area in which the human activities take place, (b) the area covered by the pressures generated by the activities on the prevailing habitats and species, in which pressures are defined as the mechanisms of change, and (c) the area over which any adverse effects occur. These features can be respectively termed the activities-footprints, the pressures-footprints and the effects-footprints. The latter in turn incorporates both the effects on the natural system and the effects on ecosystem services from which society extracts goods and benefits. This viewpoint article explains the rationale behind this typology and proposes definitions for each of these three types of footprints.

Litter is a well-known problem for marine species; however, we still know little about the extent to which they're affected by microplastics. In this study, we analyse the presence of this type of debris in Western Mediterranean striped dolphins' intestinal contents over three decades. Results indicated that frequency was high, as 90.5% of dolphins contained microplastics. Of these microplastics, 73.6% were fibres, 23.87% were fragments and 2.53% were primary pellets. In spite of the high frequency of occurrence, microplastic amount per dolphin was relatively low and highly variable (mean ± SD = 14.9 ± 22.3; 95% CI: 9.58–23.4). Through FT-IR spectrometry, we found that polyacrylamide, typically found in synthetic clothes, was the most common plastic polymer. Here, we establish a starting point for further research on how microplastics affect this species' health and discuss the use of striped dolphins as indicators of microplastics at sea.

This study estimates chemical composition of microplastic in sediments and benthic detritivores (sea cucumbers) collected from different marine rocky bottom habitat types (bank, landslide, cliff) of Salina Island (Aeolian Archipelago, Italy). Also, species richness and bottom coverings by benthic species were recorded at each sampling station. Correlations among chemical composition of microplastic in sediments and in detritivores were explored linking recorded variability to the factor “habitat type”. Results evidence that the habitat types considered in this study are characterized by wide species richness and by high percentages of bottom coverage by protected species by international conventions. In spite of the high ecological value of habitats considered in this study, microplastics were recorded both in sediments (PVC, PET, PE, PS, PA, PP) and in stomach contents of sea cucumbers (PET, PA) collected in all sampling sites, confirming the exposure of benthic species to microplastic pollution.

We determined values of antioxidant biomarkers catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione S-transferase (GST) and malondialdehyde (MDA) in two bivalve species from a subtropical system in Brazil. Differences in the biomarkers activities measured in digestive glands and gills sampled at two seasons and in sites with different levels of contamination were tested using univariate and multivariate analyses. Seasonality was the main factor accounting for overall variability. Significant SOD and GPx activities and increased levels of lipid peroxides were detected in summer, while CAT activity was higher in winter. However, biomarkers respond to complex environmental settings as indicated by the significant interaction between season and contamination level. We propose A. flexuosa as a candidate for monitoring studies with sampling occurring at a yearly timescale, and using C. rhizophorae is better suited for designs that include both seasons.

Musa estuary and its tributaries, located northwest of the Persian Gulf, host many industrial complexes, high-density ports, and urban areas along their coastal regions and are, therefore, constantly threatened by chemical contamination. The present study is the first to have investigated the surface sediments in six stations of the Musa estuary tributaries. The mean variations in BPA concentrations in the dry sediments of these stations ranged from 2.22 to 16.71 ng/g. Fairly high levels of BPA were found in Durragh station and its neighboring industrial sites. The lowest BPA level (2.22 ng/g) was observed in the station at the mouth of the Persian Gulf. Based on the EU risk-assessment system, the concentration levels of BPA in the sediments are in the low-risk range. Only in certain areas of the estuary were the sediments of moderate risk, and prolonged contact between ecological populations and them could cause toxicity in aquatic organisms.

The study, for the first time, evaluated the leaching rate of zinc oxide nanoparticles (nZnO) from human skins which were applied with three commercial sunscreens containing nZnO as an active ingredient. The leaching rate of nZnO varied greatly among the sunscreens, with a range of 8–72% (mean ± SD: 45% ± 33%). We further investigated their toxicities to the marine copepod Tigriopus japonicus. We found that 96-h median lethal concentrations of the three sunscreens to T. japonicus were > 5000, 230.6, and 43.0 mg chemical L⁻¹, respectively, equivalent to Zn²⁺ concentrations at >82.5, 3.2, and 1.2 mg Zn L⁻¹, respectively. Exposure to the individual sunscreens at environmentally realistic concentrations for 96 h led to up-regulation of antioxidant genes in T. japonicus, while they triggered the release of reactive oxygen species based on the results of in vivo assays. Evidently, these nZnO-included sunscreens can cause oxidative stress and hence pose risk to marine organisms.

Pollution in the Arabian Gulf has risen in recent decades due to rapid development in the region. We studied 21 elements in the liver, gastrointestinal (GI) tract and muscles of the Indian anchovy (Stolephorus indicus) to characterize bioaccumulation in this abundant forage fish. Mean concentrations (μg/g wet weight) of elements ranged as follows: Cd: 0.1–8.0; Cr: 0.1–24.0; Cu: 1.2–24.0; Ni: 0.3–76.5; Ca: 1237.0–15,270.0; S: 2966.0–7467.0; Zn: 7.1–247.0; V: 0.1–27.0; Hg: 0.04–0.18 and Sr: 8.1–191.0. Zn, Cu, Cr, and Cd in the tissues exceeded the maximum permissible limit recommended by FAO, WHO and EC. We suggest that bioaccumulation in fish could be a hazard for human consumption. Therefore, further monitoring is needed to better characterize pollutant levels in fish of higher trophic levels in the Arabian Gulf.

Harmful algal blooms involving the dinoflagellate Cochlodinium polykrikoides occur every summer off the Korean peninsula's central southern coast. To determine whether Cochlodinium bloom-derived organic carbon is incorporated into the subtidal macrobenthic food web, we compared the δ¹³C and δ¹⁵N values of suspended particulate organic matter (SPOM) and sedimentary organic matter, and macrobenthic consumers between bloom and non-bloom seasons. Chemotaxonomic analysis revealed the presence of Cochlodinium blooms in summer and a predominance of diatoms in autumn. Both the δ¹³C and δ¹⁵N values of SPOM were higher in the bloom than in the non-bloom seasons. Such temporal shifts in the δ¹³C and δ¹⁵N values were also observed for most macrobenthic consumers collected in both seasons. Consistent temporal isotopic shifts in SPOM and macrobenthos revealed that the Cochlodinium bloom-derived carbon was incorporated into the coastal benthic food web, resulting from its increasing availability during blooms.

Macro-litter accumulation surveys were carried out in six beaches in Kilifi, Mombasa and Kwale Counties. Macro litter were collected, quantified and characterized to determine their composition, distribution and accumulation rates. The results showed that the accumulation rates ranged between 1.53 ± 1.23 and 11.46 ± 7.72 (for dry zones) and 2.69 ± 2.13 and 8.93 ± 7.87 items m⁻¹ day⁻¹ (for wet zones). Plastics and foam were the most abundant litter categories. Local products constituted about 88% of all the collected litter. Food packaging products constituted about 91.3% of all branded litter types. Marine litter pollution particularly by plastics was widespread in all studied coastal counties. However, a significant amount of litter encountered in the beaches was of local origin, thus a local solution to waste management (that will eliminate leakage into marine environments) will considerably reduce marine litter pollution in Kenya.