Libreville, the largest city in Gabon, adversely impacts the Komo Estuary and the Akanda National Park aquatic ecosystems through discharge of domestic and industrial waste. Fecal Indicator Bacteria (FIB: Escherichia coli and fecal streptococci) were enumerated using culture-based methods in water from 40 sites between 2017 and 2019 including coastal outlets, mangrove channels, open bays and littoral rivers. Contamination levels were high in discharge waters from small urban rivers in Libreville agglomeration, frequently exceeding international safety guidelines, whereas FIB concentrations decreased downstream from the city in main mangrove channels. Littoral forest rivers were significantly impacted by fecal contamination despite the absence of settlements in the watersheds. Protected areas are not effective in avoiding FIB contamination, indicating inefficient waste management. Dedicated management policies should be implemented to reduce both the sanitary concern and global pollution, poorly assessed in a context of demographic increase in tropical littoral zones.

The deposition of remaining nanoparticles in the Caribbean Sea generates the formation of potentially dangerous elements, which influence at the imbalance of ecosystems. The detection of nanoparticles is not simple and the use of conventional methods is difficult application, which is why we highlight the immediacy and importance of this research for the areas of marine biology, urbanism, engineering and geosciences, applied in the Caribbean Sea. The general objective of this study is to evaluate the use of advanced methods for the determination of toxic nanoparticles, which can directly affect the development of marine organisms in the aquatic ecosystem in waters of the Caribbean Sea, favoring the construction of future international public policies with the elaboration of projects capable of mitigating these levels of contamination. The morphology and structure of nanoparticles were analyzed by emission scanning electron microscope with a high-resolution electron microscope. The nanoparticles smaller than 97 nm were identified in different proportions. The morphological analyses indicated nanoparticles' presence in the form of nanotubes, nanospheres, and nanofibers, which were shown in an agglomerated form. The presence of potentially hazardous elements, such as As, Cd, Pb, Mg, Ni and V were verified. In addition, the presence of asbestos in the form of minerals was confirmed, and that of titanium dioxide was found in large quantities. The results provide new data and emphasize the possible consequences to the in the Caribbean Sea, with the identification of dangerous elements (As, Cb, Pb, Hg, Ni and V), harmful to the marine ecosystem. Therefore, there is a need for strict control to reduce contamination of the Caribbean Sea and avoid risks to the ecosystem and public health, through suggestions of international public policies, through constant monitoring and the application of environmental recovery projects in this marine estuary.

Human disturbance of karst landscapes in tropical volcanic islands present a unique challenge for understanding sediment transport to the coastal zone. Here we present the first evidence of urban drinking water quality impacts from industrial logging in the Solomon Islands. Despite only 6% of the Honiara's drinking water catchment being disturbed by logging, rhodamine dye tracers demonstrated complex karst sinkholes that led to high suspended sediment concentrations being transported from neighbouring Kovi catchment into the Kongulai water supply offtake point for Honiara. This has resulted in the exceedance of practical treatment thresholds of 20 NTU 9.5% of the time, leading to water supply for the majority of Honiara's residents being unavailable for 58 days in 2019. This work highlights the cost-benefit disparity between industrial logging yielding minimal short-term economic yields in comparison to on-going broader impacts of increased coastal sediment transport while restricting water supply to a developing nation's capital.

Numerous studies have estimated the abundance of plastics in our oceans and warned of its threat to wildlife. However, mechanisms underlying its attractiveness to marine life remain unclear. Though visual similarities to food sources have been suggested, recent studies show that biofouled plastics release dimethyl sulfide which marine fauna mistake for food whilst foraging. Our study shows that the plastic additive oleamide (9-octadecenamide) attracts hermit crabs (Pagurus bernhardus). Respiration rate increases significantly in response to low concentrations of oleamide, and hermit crabs show a behavioral attraction comparable to their response to the feeding stimulant betaine. Oleamide has a striking resemblance to the necromone oleic acid, a chemical released by arthropods during decomposition. As scavengers, hermit crabs may misidentify oleamide as a food source, creating an olfactory trap. As such, our short communication demonstrates that additive leaching may play a significant role in the attraction of marine life to plastic.

Microplastics (MPs) in oceans adsorb different types of pollutants, which can negatively impact the food chain. The extensive use of personal care products (PCPs) has led to their ubiquitous environmental presence, and their partition between plastic matrices and surroundings is determined by their physico-chemical characteristics and environmental conditions. This work develops and applies a methodology to determine 12 UV filters (UVFs) and UV stabilisers (UVSs) in MPs collected in beach sand. The analyses were carried out by ultrasound-assisted extraction and ultrahigh-performance liquid chromatography with tandem mass spectrometry detection. The validated procedure was applied to MPs samples taken in sand samples from 13 beaches on the Canary Islands (Spain). The results showed the presence of 10 UV filters and UV stabilisers at concentrations between 1 and 4031 ng·g⁻¹, where octocrylene was the most frequently found. The target analytes were present in all the sampling beaches.

Microplastic pollution has received substantial international attention in terrestrial and marine environments and in the atmosphere. In this study, we assessed microplastic pollution and analyzed the accumulation of microplastics in the gills of fish caught in the Zhoushan fishing ground from September 2017 to March 2018. The average abundance of microplastics was 0.49 ± 0.54 particles/gill and frequently found chemical polymers was polyethylene terephthalate. We also conducted experiments on microplastic pollution in the water and the working solutions used during the analytical process and found that the source of microplastic contamination was the solutions used. Moreover, we evaluated and scored experimental quality control and quality assurance adapted from the ‘Total Accumulated Score’ method. Valuable steps are recommended in order to produce reliable results and improve the quality of results in microplastic analyses.

This paper examines which demographic and attitudinal characteristics relate to an individual's knowledge and perception of the environmental footprint of single-use mask s/he is using in the midst of the COVID-19 pandemic. Based on a self-selected sample of Greek citizens (N = 462), it is found that demographic characteristics and pro-environmental concern are unrelated to the single-use mask users' knowledge and concern regarding the environmental impacts of the mask they are using. This unanticipated finding suggests that the circumstances of the COVID pandemic may mute the theoretically taken-for-granted connection between environmental interest/concern and the awareness of environmental impacts, thus any future attempts to introduce more environmentally-friendly single-use mask alternatives and/or to curb the current ones' environmental impact should start by reenergizing this suppressed nexus.

Suspended mariculture has significantly influences on the benthic sediment. However, our understanding on how bacterial communities respond to mariculture induced changes in redox profiles is limited. In present study, sediments from two maricultures and reference areas were collected and incubated for 28 day. The results indicated that the dominant pathway of organic matter mineralization in the sediment varied from groups, in the reference, it was the iron reduction, but in the two mariculture groups it was the SO₄²⁻ reduction. Remarkable changes of bacteria community were recorded in the aerobic zone, where the abundances of 14 OTUs belonging to Gammaproteobacteria and Alphaproteobacteria were significantly higher than that in oxidation and anaerobic zones. However, 4 keystone OTUs were strictly anaerobic and belonging to Desulfobacteraceae (n = 3) and Marinilabiaceae (n = 1). The main environmental drivers determining sediment bacterial distribution were the particle organic carbon, dissolve oxygen, NO₃⁻, and moisture content.

The present pilot study aimed to provide an overview of organic contaminant concentration levels in the littoral ecosystems of the Pertuis seas. The study determined the concentrations of twenty-nine pesticides, six nonylphenols and seven polybrominated diphenyl ethers (PBDEs) in sediments, seawater, Pacific oysters and blue mussels. Oysters accumulated a higher number of pesticides than blue mussels. Indeed, alpha BHC (0.60–0.72 ng/g, ww), chlorfenvinphos (1.65–2.12 ng/g, ww), chlorpyrifos (0.79–0.93 ng/g, ww), chlortoluron (2.50–4.31 ng/g, ww), metolachlor (up to 0.38 ng/g, ww) and parathion (0.56–0.69 ng/g, ww) were quantified in oysters whereas only alpha BHC (0.24–0.31 ng/g, ww), was quantified in mussels. The present results also revealed that the POPs detected in water or sediments were not ultimately found accumulated in bivalves. Other molecules such as methylparathion and BDE47 were quantified in sediments. These molecules, BDE99 and one nonylphenol (OP2OE) were quantified in seawater. Finally, the comparison with the available environmental guidelines showed that the values measured were at concentrations not considered to cause adverse effects at the populations' level except for chlortoluron in seawater (15–50 ng/L).

Marinas have ceased to be ports dedicated exclusively to recreational boating and nautical sports. Nowadays, marinas offer a variety of services that complement the tourist offering of its locality in addition to auxiliary activities that arise from its main activity. There are considerable economic and social resources generated by these types of facilities that benefit their localities, but they can also have negative effects such as compromising the sustainability of the environment.The objective of this article is to examine the terms related to changes in the ecosystem derived from marinas through the Keywords Plus and the Author Keywords extracted from the WoS database and obtain results that explain how several themes have evolved and how these concepts relate to each other and to other variables. In this way, it will be possible to critically examine the selection of terms that appear in scientific documents. The results show that pollution, antifouling paints, and invasive species are the terms of greatest concern and on which particular emphasis should be placed for future lines of research.