This article presents a literature review of solid waste management on cruise ships using a bibliographic search of the main databases. Articles that discuss waste management were spread over different research areas, demonstrating that the topic is cross-sectional and interconnected, involving social, economic and political considerations. The text is organized into four topics: generation, treatment, disposal and impacts. Recent years have seen increasing interest in cruise ship waste management, likely due to the growing tourism market, with an annual increase of 7.4% in the number of passengers between 1990 and 2018. However, this growth may aggravate environmental, social and economic impacts, making it essential to promote research and studies in the area.

Trace elements can be accumulated from coastal environment by aquatic organisms from their food and be transferred throughout the food webs. Studying the effects of salinity on the trophic transfer of trace elements in a euryhaline fish, able to deal with large variations in salinity, is therefore key to understand their dynamics in aquatic environments. In this context, we investigated the potential influence of salinity on the trophic transfer of two essential elements (Mn and Zn) in the euryhaline fish, the turbot Scophthalmus maximus using radiotracer techniques. After acclimation to three salinities (10, 25 and 38), turbots were fed with radiolabelled pellets (⁵⁴Mn and ⁶⁵Zn). Kinetic parameters of depuration were determined after a 21-d period and trophic transfer factors were calculated. Trophic transfer of Mn at the highest salinity was significantly lower than for the other conditions whereas salinity did not significantly influenced Zn trophic transfer. Differences in the processes involved in the regulation (homeostasis) of the two tested trace elements may explain the contrasting influence of seawater salinity for Mn and Zn.

This study evaluates the potential area and the key environmental factors supporting Sargassum bed restoration (SBR) in the highly turbid northwestern Arabian Gulf where rapid coastal development impinges on the marine ecosystem functioning. Water depth was a primary environmental factor governing the distribution of the subtidal macroalgae beds in these turbid waters. The relationship between Sargassum coverage and water depth measured by an echo sounder indicated optimal water depths where the maximum coverage was observed. The availability of stable hard substrate was another key factor introducing heterogeneity in Sargassum coverage. Potential area for the SBR estimated based on the optimal depths was 4.26 km², whereas only 50% of the potential area (2.19 km²) was currently vegetated due to the absence of hard substrate. The outcomes of this study offer beneficial information toward implementation of the SBR as a part of mitigation measures in future coastal development plans in the region.

The majority of aquatic toxicity data for petroleum products has been limited to a few intensively studied crude oils and Corexit chemical dispersants, and acute toxicity testing in two standard estuarine test species: mysids (Americamysis bahia) and inland silversides (Menidia beryllina). This study compared the toxicity of two chemical dispersants commonly stock piled for spill response (Corexit EC9500A®, Finasol®OSR 52), three less studied agents (Accell Clean®DWD dispersant; CytoSol® surface washing agent; Gelco200® solidifier), and three crude oils differing in hydrocarbon composition (Dorado, Endicott, Alaska North Slope). Consistent with listings on the U.S. National Contingency Plan Product Schedule, general rank order toxicity was greatest for dispersants and lowest for the solidifier. The results indicate that freshwater species can have similar sensitivity as the conventionally tested mysids and silversides, and that the sea urchin (Arbacia punctulata) appears to be a reasonable addition to increase taxa diversity in standardized oil agent testing.

Microplastics (MPs) in the surface water of the Qiantang River and its tributaries were investigated in this study, to evaluate the contribution of riverine discharge on emerging pollution load in the Hangzhou Bay. The abundance of MPs (mean 1183 ± 269 particles/m³) showed spatially and temporally heterogeneous in the surface water. Polyamide, polyester, and polyethylene teraphalate were the major components, accounting for 77.4% of all polymer types. Fiber was the most common shape, indicating the potential anthropogenic sources of MPs. The MPs flux from the Qiantang River to the Hangzhou Bay was estimated to be 2831 tons/year, implying the importance of riverine discharge in an estuarine bay. The inputs from the complicated tributaries system led to a 20-fold increase of MPs flux, and would significantly improve their budget of downstream and estuary, so we suggested the control and management on plastic pollution should be strengthened in all aspects.

The risk to Arctic aquatic species due to accidental oil spills is not well studied. One of the key reasons for this limitation is the lack of understanding of the dose-response relations for the species in the Arctic region. The present study addresses this knowledge gap. It proposes a new approach to develop dose-response curves for Arctic aquatic species. The application of the approach is demonstrated using the estimation of mortality risk in Boreogadus saida (polar cod) due to exposure from polycyclic aromatic hydrocarbons (PAH).The proposed approach considers the toxicity mechanism in Arctic species (i.e. polar cod) and regional environmental factors, and models these as a belief-based Bayesian Network (BN). The BN model integrates diverse ecotoxicology biomarker data types and predicts the cell death probability due to exposure to a toxicant (PAH in crude oil). The input data and results from the model were verified using data available in the literature. Seasonal sea ice played a major role in containing PAH exposure and subsequent risk to polar cod. However, the physiological factors, such as presence of higher Phase II activity, and higher oxyradical scavenging ability, had greater impact on PAH risk mitigation.

Existing marine bioregions covering the Pacific Ocean are conceptualised at spatial scales that are too broad for national marine spatial planning. Here, we developed the first combined oceanic and coastal marine bioregionalisation at national scales, delineating 262 deep-water and 103 reef-associated bioregions across the southwest Pacific. The deep-water bioregions were informed by thirty biophysical environmental variables. For reef-associated environments, records for 806 taxa at 7369 sites were used to predict the probability of observing taxa based on environmental variables. Both deep-water and reef-associated bioregions were defined with cluster analysis applied to the environmental variables and predicted species observation probabilities, respectively to classify areas with high taxonomic similarity. Local experts further refined the delineation of the bioregions at national scales for four countries. This work provides marine bioregions that enable the design of ecologically representative national systems of marine protected areas within offshore and inshore environments in the Pacific.

This paper aimed at evaluating the total mercury content in five common fish species from the western European Atlantic coastal waters, and the associated risk of consumption. Mercury concentrations in muscle of Atlantic mackerel (Scomber scombrus), Atlantic chub mackerel (Scomber colias), European anchovy (Engraulis encrasicolus), Atlantic horse mackerel (Trachurus trachurus) and European pilchard (Sardina pilchardus) ranged from 0.003 to 0.20 mg kg⁻¹ wet weight, and no significant differences were observed between the average concentration in each species. A significant increasing trend in mercury content with fish size was observed for all species (except for European anchovy), suggesting mercury bioaccumulation throughout their life cycle. Still, the mercury content was far below the European Food Safety Authority and World Health Organization food safety thresholds in all species, highlighting the low risk to human health due to the ingestion of these species and the importance of consumer options for risk reduction.

The degree of organotin compounds (OTCs), including dibutyltin, tributyltin, triphenyltin and dioctyltin, contamination in seafood purchased in 2017 and 2018 from Hong Kong market was studied. Edible portions of 341 seafood samples, including fish, crustaceans and molluscs, were used for analysis by gas chromatograph coupled to an inductively coupled plasma mass spectrometry (GC-ICP/MS). The method detection limits and quantification limits of OTCs were below or equal to 0.25 and 1.0 μg Sn kg⁻¹ respectively. Triphenyltin accounted for the majority amongst other OTCs and was detected in 53% of samples. In general, mean total OTCs levels of fish (24 μg Sn kg⁻¹) were higher than crustaceans (14 μg Sn kg⁻¹) and molluscs (15 μg Sn kg⁻¹). The highest detected levels of triphenyltin, tributyltin, dibutyltin and dioctyltin were found to be 480, 24, 4.5 and 0.89 μg Sn kg⁻¹ in a mangrove snapper, noodle fish, coral clam and giant grouper respectively.

Coral reef ecosystems are declining due to multiple interacting stressors. A bioassessment framework focused on stressor-response associations was developed to help organize and communicate complex ecological information to support coral reef conservation. This study applied the Biological Condition Gradient (BCG), initially developed for freshwater ecosystems, to fish assemblages of U.S. Caribbean coral reef ecosystems. The reef fish BCG describes how biological conditions changed incrementally along a gradient of increasing anthropogenic stress. Coupled with physical and chemical water quality data, the BGC forms a scientifically defensible basis to prioritize, protect and restore water bodies containing coral reefs. Through an iterative process, scientists from across the U.S. Caribbean used fishery-independent survey data and expert knowledge to develop quantitative decision rules to describe six levels of coral reef ecosystem condition. The resultant reef fish BCG provides an effective tool for identifying healthy and degraded coral reef ecosystems and has potential for global application.