Microplastics (≤ 10 µm) bioaccumulation in marine sponges along the Moroccan Mediterranean coast: Insights into species-specific distribution and potential bioindication.

Microplastics (MPs) are pervasive in marine environments and widely recognized as emerging environmental pollutants due to the multifaceted risks they exert on living organisms and ecosystems. Sponges (Phylum Porifera) are essential suspension-feeding organisms that may be highly susceptible to MPs uptake due to their global distribution, unique feeding behavior, and sedentary lifestyle. However, the role of sponges in MP research remains largely underexplored. In the present study, we investigate the presence and abundance of MPs (≤10 µm size) in four sponge species, namely Chondrosia reniformis, Ircinia variabilis, Petrosia ficiformis, and Sarcotragus spinosulus collected from four sites along the Mediterranean coast of Morocco, as well as their spatial distribution. MPs analysis was conducted using an innovative Italian patented extraction methodology coupled with SEM-EDX detection. Our findings reveal the presence of MPs in all collected sponge specimens, indicating a pollution rate of 100%. The abundance of MPs in the four sponge species ranged from 3.95×105 to 1.05×106 particles per gram dry weight of sponge tissue, with significant differences observed among sampling sites but no species-specific differences. These results imply that the uptake of MPs by sponges is likely influenced by aquatic environmental pollution rather than the sponge species themselves. The smallest and largest MPs were identified in C. reniformis and P. ficiformis, with median diameters of 1.84 µm and 2.57 µm, respectively. Overall, this study provides the first evidence and an important baseline for the ingestion of small MP particles in Mediterranean sponges, introducing the hypothesis that they may serve as valuable bioindicators of MP pollution in the near future.

Evaluating the effectiveness of coastal environmental management policies in China: The case of Bohai Sea.

With marine pollution issues becoming serious and widespread, a series of coastal environmental managemental policies are being carried out worldwide, the effectiveness of which requires comprehensive evaluation. Taking the Bohai Sea (BS) of China as an example, which has been plagued by serious ecological and environmental issues for decades due to terrestrial pollution discharge, this study explored and quantified, for the first time to our best knowledge, the variability of water quality after initiating a dedicated 3-year pollution control action (Uphill Battle for Integrated Bohai Sea Management, UBIBM, 2018-2020) implemented by China's central government, with two water quality indexes of water color (Forel-Ule index, FUI) and transparency (Secchi disk depth, ZSD, m) from satellite observations. During the UBIBM, a significant improvement in water quality was detected, characterized by a clearer and bluer BS, with ZSD and FUI improved by 14.1% and 3.2%, respectively, compared with the baseline period (2011-2017). In addition, an abrupt drop in the long-term record (2011-2022) of the coverage area of highly turbid waters (ZSD≤2 m or FUI≥8) was found in 2018, which coincided with the start of the UBIBM, indicating that the water quality improvement may be attributed to the pollution alleviation of the UBIBM. Independent data of land-based pollution statistics also supported this deduction. (3) Compared with the previous two pollution control actions in the first decade of 21st century, UBIBM was proved to be the most successful one in terms of the achieved highest transparency and lowest FUI during the past two decades. Reasons for the achievement and implications to future pollution control are discussed for a more sustainable and balanced improvement in the coastal environment. This research provides a valuable example that satellite remote sensing can play a vital role in the management of coastal ecosystems by providing effective evaluation of pollution control actions.

Impact of domestic and industrial effluent on marine environment at Karachi Port Trust (KPT) coastal area, Pakistan.

The extent of aquatic pollution of Karachi Port Trust (KPT) coastal area located at the south of Pakistan coast has increased considerably in the last few decades due to unrestricted discharge of sanitary waste. The current study lays emphasis on the identification of vulnerable zones severely impacted by pollution in the KPT coastal area using laboratory monitoring, geospatial techniques, and statistical analysis. During 2019, sampling was conducted along the KPT coastal area, and 54 samples of seawater were collected during pre- and post-monsoon seasons. The outcomes of physical and chemical analysis revealed that the concentrations of BOD (biochemical oxygen demand), COD (chemical oxygen demand), nitrate, phosphate, phenol, cyanide, and oil and grease frequently exceeded the permitted limit of international norms and reached much greater levels. The levels of perilous metals in the seawater samples were in the order Ni>Cr>Cu>Pb>Cd>As in both phases and also reached to elevated levels as a consequence of the indiscriminate discharge of untreated industrial and domestic wastewater. Based on detailed examination during pre- and post-monsoon, six sites near KPT, Lyari River outfall, and Karachi Harbour were identified as highly polluted zones due to heavy discharge of sanitary effluents at these sites. In particular, the industrial zones present in the formal and informal sectors of Karachi are responsible for the deterioration of the KPT coastal area. Therefore, it is advised to design and build a submerged drainage system to transport and distribute massive amounts of treated municipal and industrial waste to the deep open sea in order to minimize the high pollutant levels in these locations.

Atmospheric PAHs in rural, urban, industrial and beach locations in Buenos Aires Province, Argentina: sources and health risk assessment.

The first atmospheric PAHs levels and associated inhalation cancer risk were assessed over southwest Buenos Aires region by deploying PUF disk PAS samplers. Eight sampling location included coastal zones, touristic beaches, and rural inland areas were considered. PUF disks were fortified with surrogate standards and extracted by automated Soxhlet prior to GC-MS analysis. Σ16 PAHs ranged from 1.13 to 44.5 ng m-3 (10.3 ± 9.8), while urban locations showed up to 10 times higher PAH levels than rural or beach locations. Direct sources of PAHs, such as intensive vehicle traffic, heating, and general combustion activities, were identified. PAHs with four to six rings (46.62%) were predominantly Flt, Pyr, BbF, and BkF, and carcinogenic risk was expressed by BaP (0.10 ± 0.07 ng m-3) and BaPTEQs (0.26 ± 0.22 ng m-3). Inhalation ECR (2.23E-5, WHO) presented the lowest risk at beach locations. Molecular ratios and PCA showed a strong dominance in pyrolytic sources, such as biomass and coal combustion, with a particular signature in fires at inland locations. Overall, this study demonstrated that PUF disk passive air sampling provided a sound and simple approach for tracking air PAHs, their sources and public health risks, bringing a cost-effective tool for pollution control measures, even at small and remote towns. This is particularly relevant in extensive countries with medium or low income, such as Argentina.

When, where, and how to intervene? Trade-offs between time and costs in coastal nutrient management.

Policies and regulations designed to address nutrient pollution in coastal waters are often complicated by delays in environmental and social systems. Social and political inertia may delay implementation of cleanup projects, and even after the best nutrient pollution management practices are developed and implemented, long groundwater travel times may delay the impact of inland or upstream interventions. These delays and the varying costs of nutrient removal alternatives used to meet water quality goals combine to create a complex dynamic decision problem with trade-offs about when, where, and how to intervene. We use multi-objective optimization to quantify the trade-offs between costs and minimizing the time to meet in-bay nutrient reduction goals represented as a Total Maximum Daily Load (TMDL). We calculate the impact of using in-bay (in-situ) nutrient removal through shellfish aquaculture relative to waiting for traditional source control to be implemented. We apply these methods to the Three Bays Watershed in Cape Cod, Massachusetts. In gross benefit terms, not accounting for any social costs, this equates to an average value of 37¢ (2035 TMDL target date) and 11¢ (2060 TMDL target date) per animal harvested over the plan implementation period. Our results encourage the consideration of alternative and in-situ approaches to tackle coastal pollution while traditional source control is implemented and its effects realized over time.

Geochemical speciation of metals (Cu, Pb, Cd) in fishpond sediments in Batan Bay, Aklan, Philippines.

Batan Bay in Aklan, Philippines supports a population largely dependent on coastal fisheries. The development of aquaculture technologies coupled with over-crowded fish pens has negatively affected its natural dynamics and environmental quality. Land-use activities including ports and shipyard further aggravate the problem by contributing to chemical pollution. The present study applied sequential extraction techniques to determine the geochemical speciation of metals in fishpond sediments. Samples were processed and analyzed for Cu, Cd, and Pb using flame atomic absorption spectroscopy. Copper (Cu) showed the highest concentration (10.61-66.81 µg/g-dry weight of sediment). Lead (Pb) content ranged from below detection limit to 15.14 µg/g, while Cd concentration ranged from below detection limit to 2.50 µg/g. Fractionation study showed that the Cu present in the fishpond sediments is mostly non-residual (50.03-73.34%) and significantly associated with the oxidizable fraction (33.89-64.75%). In contrast, the residual fraction served as the dominant host of Pb (33.55-62.68%) in the sediments. Comparison of the results with US EPA and NOAA sediment quality guidelines also revealed that the Batan Bay sediments may be considered generally non-polluted with respect Cu, Pb, and Cd, and not expected to cause adverse effects to aquatic organisms under normal conditions. However, under certain redox conditions, most of the sites may be considered moderately polluted as a result of Cu mobilization from the non-residual fractions of the sediments. Overall, geochemical speciation studies in an important fishery area like Batan Bay will provide valuable insights into the availability of metal contaminants to aquatic organisms under certain environmental conditions.

Organic ultraviolet (UV) filters in the South China sea coastal region: Environmental occurrence, toxicological effects and risk assessment.

Organic ultraviolet (UV) filters are common ingredients of personal care products and occur ubiquitously in the aquatic environment; however, little is known about their distribution in and potential effects to the marine environment. This study reports the occurrence, toxicological effects and risk assessment of eleven commonly consumed UV filters in marine surface water collected from the South China Sea (SCS) coastal region. The concentrations of UV filters ranged from

Mussels do not directly assimilate fish farm wastes: Shifting the rationale of integrated multi-trophic aquaculture to a broader scale.

Pollution is one of the most significant issues that is currently impeding the development of fish farming. Integrated multi-trophic aquaculture (IMTA) has the potential to reduce the accumulation of organic wastes in the environment by using taxa of lower trophic levels such as filter feeders. However, the capacity of filter feeders to assimilate significant quantities of fish farm wastes has not yet been fully tested in situ. We analyzed the stable isotopes δ13C and δ15N in mussels from six fish farms and from six other areas that were not influenced by fish farming, at two water strata (surface and mid-water) across a marked gradient of eutrophication along more than 900 km of coastline in the Western Mediterranean. We found that the mussels did not directly assimilate fish farming wastes. Consequently, fish farming wastes did not constitute a major component of mussel diet, irrespective of local productivity and depth in the water column. These outcomes do not necessarily mean that IMTA is not suitable in other cases, but rather that there should be a shift in the rationale of IMTA by modifying the concept of direct assimilation of wastes to a more general approach of IMTA based on regional budgets of nutrients.

Investigating the impacts of treated effluent discharge on coastal water health (Visakhapatnam, SW coast of Bay of Bengal, India).

The present study investigated the impacts of treated effluent discharge on physicochemical and biological properties of coastal waters from three pharmaceuticals situated along the coast of Visakhapatnam (SW Bay of Bengal). Seawater samples were collected (during the months of December 2013, March 2014 and April 2014) from different sampling locations (Chippada (CHP), Tikkavanipalem (TKP) and Nakkapalli (NKP)) at 0- and 30-m depths within 2-km radius (0.5 km = inner, 1 km = middle and 2 km = outer sampling circles) from the marine outfall points. Physicochemical and biological parameters, which differed significantly within the stations, were likely to be influenced by strong seasonality rather than local discharge. Dissolved oxygen variability was tightly coupled with both physical and biological processes. Phytoplankton cell density and total chlorophyll (TChla) concentrations were significantly correlated with dissolved inorganic nutrient concentrations. CHP (December) represented a diatom bloom condition where the highest concentrations of diatom cells, total chlorophyll (TChla), dissolved oxygen coupled with lower zooplankton abundance and low nutrient levels were noticed. The centric diatom, Chaetoceros sp. (> 50%) dominated the phytoplankton community. TKP (March) represented a post-diatom bloom phase with the dominance of Pseudo-nitzschia seriata; zooplankton abundance and nutrient concentrations were minimum. Conversely, NKP (April) represented a warm well-stratified heterotrophic period with maximum zooplankton and minimum phytoplankton density. Dinoflagellate abundance increased at this station. Relatively higher water temperature, salinity, inorganic nutrients coupled with very low concentrations of dissolved oxygen, TChla and pH were observed at this station. Copepods dominated the zooplankton communities in all stations and showed their highest abundance in the innermost sampling circles. Treated effluent discharge did not seem to have any significant impact at these discharge points.

Systemic effects of settleable atmospheric particulate matter (SePM) on swamp ghost crab Ucides cordatus.

Metallurgical activities are a significant source of settleable atmospheric particulate matter (SePM). The material is exposed to wind action, leading to its deposition throughout terrestrial and aquatic ecosystems, thus promoting contamination by metals and metalloids. However, knowledge of the impacts on biota is scarce. In aquatic coastal zones, evaluating hemolymph in invertebrates makes it possible to have insights into the pre-pathogenic effects and health status of organisms. Our study aimed to evaluate bioaccumulation and the sublethal effects of SePM on the mangrove crab Ucides cordatus by assessing biomarkers of cito-genotoxicity in the hemolymph. Organisms underwent a 30-day experiment with four treatments: control; 0.01 g.L-1, 0.1 g.L-1, 1 g.L-1 of SePM, with hemolymph sampled at 2, 7, 15, and 30 days of exposure to assess lipid peroxidation (LPO), DNA damage (strand break), cholinesterase (ChE) and lysosomal membrane stability (LMS). The results revealed metals' bioaccumulation in soft tissues (Al, Fe+, Fe++, Cu, Zr, Nb) and dose-time-dependent responses for LPO, DNA strand break, ChE, and LMS. Significant correlation was found between LPO and Cu (tissue), reduced LMS and Al and Fe (tissue), and Cu, Zn, Ag, and Bi in water. Hemolymph was related to the toxicokinetic and toxicodynamic of metals and metalloids from SePM in Ucides cordatus. New toxicological evidence was obtained to shed light on the impacts of SePM on the ecological status of coastal zones.

Marine litter weight estimation from UAV imagery: Three potential methodologies to advance macrolitter reports.

In the context of marine litter monitoring, reporting the weight of beached litter can contribute to a better understanding of pollution sources and support clean-up activities. However, the litter scaling task requires considerable effort and specific equipment. This experimental study proposes and evaluates three methods to estimate beached litter weight from aerial images, employing different levels of litter categorization. The most promising approach (accuracy of 80 %) combined the outcomes of manual image screening with a generalized litter mean weight (14 g) derived from studies in the literature. Although the other two methods returned values of the same magnitude as the ground-truth, they were found less feasible for the aim. This study represents the first attempt to assess marine litter weight using remote sensing technology. Considering the exploratory nature of this study, further research is needed to enhance the reliability and robustness of the methods.

A transcontinental threat: Plastic waste from Africa invades Brazil's coast.

Identifying the origin of plastic pollution is essential for the development of effective preventive and mitigatory strategies and guidelines for companies, governments, and stakeholders. In 2022, a considerable amount of plastic waste stranded on beaches of the northeastern coast of Brazil. A preliminary analysis of this waste revealed that most of the items were likely foreign made, and a brand auditing approach was applied to identify the brands, parent companies, and potential origin of the plastic waste. The items were also examined to determine their degree of degradation, polymer resin codes, colors, and probable uses. Given their probable foreign origin, a numerical simulation was employed using the OpenDrift dispersion model to determine the likely route each item would have taken before reaching the Brazilian coast. The brand audit confirmed that most of the plastic waste came from Africa (78.5 % of the items), followed by Brazil (15.7 %), and other nations (5.8 %). A total of 31 brands from seven African countries were identified, of which, >90 % originated from the Democratic Republic of the Congo. Drift simulations were consistent with the results of the brand audit, indicating that the plastics originated from the west coast of African, primarily between latitudes 5° N and 10° S. This analysis indicated that the Congo river was the principal source of the plastic waste that found its way to the Brazilian beaches. The present study highlights the widespread occurrence of plastic pollution across the Atlantic Ocean and underscores the need for mitigatory and regulatory measures that consider foreign sources, as well as local drivers of pollution. In this context, continuous monitoring programs will be essential to advance our understanding of the magnitude of the international plastic pollution problem, and provide insights to delineate specific enforcements dealing with this issue.

How much does marine litter weigh? A literature review to improve monitoring, support modelling and optimize clean-up activities.

The weight of marine litter has been marginally considered in comparison to counting and categorizing items. However, weight determines litter dynamics on water and coasts, and it is an essential parameter for planning and optimizing clean-up activities. This work reviewed 80 publications that reported both the number and weight of beached macro-litter worldwide. On average, a litter item weighed 19.5 ± 20.3 g, with a median weight of 13.4 g. Plastics composed 80% by number and 51% by weight of the global litter bulk. A plastic item weighed 12.9 ± 13.8 g on average, with a median weight of 9 g. The analysis based on continents and on water bodies returned similar values, which can be used to estimate litter weight on beaches from past and future visual census surveys, and from remote sensing imagery. Overall, this work can improve litter monitoring reports and support dynamics modelling, thereby contributing for environmental protection and mitigation efforts.

Capability of space borne multispectral image for detecting discoloration in optically complex coastal waters.

Coastal pollutants, from harmful algal blooms, sewage and industrial discharges, pose severe risks to marine ecosystems and public health. Recently, Promenade Beach in Puducherry, Southeast-India, experienced reddish-brown water discoloration, suspected to result from either algal blooms or suspended matter. This study monitored the spatial extent and characteristics of the discoloration using Sentinel-2 satellite images from September to November 2023, with field observations and laboratory analyses. Analyses included measurements of chlorophyll-a (Chl-a), Total Suspended Matter (TSM), and the Normalized Difference Chlorophyll Index (NDCI) to differentiate between algal blooms and other pollutants. The satellite data indicated extents of discoloration, with high TSM concentrations (>45 g/m3) and negative NDCI values suggesting absence of algal blooms. No mortality of aquatic organisms was observed during this discoloration, indicating no deleterious impact on aquatic life. This approach highlights the importance of combining satellite technology with field data for effective coastal pollution monitoring, essential for protecting marine ecosystems.

Water exchange capability induced by seasonal and regional variability: Assessment of Hong Kong waters.

Assessing water exchange capability is an essential step to understand the vulnerability of waterbody to potential pollution. To characterize the spatiotemporal variations of water exchange rate in Hong Kong waters, a three-dimensional hydrodynamic and transport model was implemented. In this study, water residence time (Tre) representing the water exchange rate was <10 days in open waters but exceeded 60 days in weakly-flushed Tolo Harbour. Sensitivity experiments revealed that river discharge accelerated water exchange in western areas, especially during the wet season, causing 45 % ~ 37 % declines in regional Tre. Conversely, tidal currents were the primary limiting factor, particularly during winter. Furthermore, the seasonal reversal of vertical Tre difference in Mirs Bay demonstrated how intrusion water facilitates water exchange by dilution effects. This comprehensive assessment of coastal water exchange capability not only enhances understanding of local marine pollution distribution but also informs coastal management strategies, which can be applied to other coastal water areas.

Integrated biomarker responses in wild populations of the intertidal sea anemone Bunodosoma zamponii living under different anthropogenic pressures.

Bunodosoma zamponii is the most abundant anemone in Mar del Plata (Buenos Aires, Argentina). Given that the presence of persistent organic pollutants (organochlorine pesticides and PCBs) and the organophosphate pesticide chlorpyrifos has recently been reported in this species, two wild populations living under different anthropogenic pressures were studied and compared regarding basic aspects of their ecology and physiological response to oxidative stress. A population from an impacted site (Las Delicias, LD) and another from a reference site (Punta Cantera, PC) were monitored seasonally (spring, summer, autumn, and winter), for one year. Anemones from PC were larger and more abundant than those from LD for most sampling periods. During winter, glutathione-S-transferase and catalase activities were higher in LD. Moreover, protein content and antioxidant defenses were higher in anemones from PC during winter as well. Taking into account their ecology (size and abundance) and biomarker responses, the population from PC was comparatively healthier. Furthermore, such differences are in agreement with recent studies indicating a higher concentration of pollutants in anemones from LD (specially during the winter sampling). In this sense, considering that B. zamponii can bioaccumulate the aforementioned pollutants, its resilience to their presence, and the fact that biomarker response differed between sites, this species can be regarded as a proper sentinel species of environmental pollution. Overall, this anemone seems to be a good bioindicator to be considered in future biomonitoring and ecotoxicological studies.

Microcosm experiment investigating climate-induced thermal effects on human virus viability in seawater: qPCR vs capsid integrity for enhanced risk management.

Climate change is intensifying extreme weather events in coastal areas, leading to more frequent discharge of untreated wastewater containing human viruses into coastal waters. This poses a health risk, especially during heatwaves when bathing activity increases. A study examined the survival and viability of seven common wastewater viruses in seawater at different temperatures. Viral genomes were quantified using direct qPCR, whilst viability was assessed using Capsid Integrity qPCR. Results showed that T90 values from direct qPCR were much higher than those from CI-qPCR, suggesting that risk mitigation should be based on viral integrity tests. All viruses remained potentially viable for at least 72 h in environmental seawater and longer in sterile artificial seawater, highlighting the importance of biotic processes in viral inactivation. Viral persistence decreased with increasing temperature. Whilst heatwaves may partially reduce risks from human viral pathogens in coastal waters, they do not eliminate them entirely.

Ingestion and depuration of polyester microfibers by Crassostrea gasar (Adanson, 1757).

The study aimed to obtain environmentally relevant microfibers (MFs) from polyester fabric and assess their impact on the oyster Crassostrea gasar. MFs were obtained by grinding the fabric, and their accumulation in oysters gills and digestive glands was analyzed after exposure to 0.5 mg/L for 2 and 24 h. Additionally, a 48 h depuration was conducted on the oysters exposed for 24 h. Sublethal effects were assessed in oysters exposed for 24 h and depurated for 48 h, using biomarkers like Catalase (CAT), Glutathione S-transferase (GST), and Glutathione Peroxidase (GPx), along with histological analyses. Polyester fabric grinding produced significant MFs (average length: 570 µm) with degraded surface and increased malleability. Oysters showed increased MF accumulation in digestive glands post-exposure, with no impact on antioxidant enzymes. Depuration decreased MFs accumulation. Histological analysis revealed accumulation in the stomach and brown cells, possibly indicating inflammation. This raises concerns about MFs bioaccumulation in marine organisms, impacting the food chain and safety.

Patterns of light pollution on sea turtle nesting beaches in the Egyptian Red Sea.

We examined the probability of past sea turtle nesting as a function of light intensity and patterns of temporal changes of light along nesting beaches in the Egyptian Red Sea. Beaches had a lower probability of past sea turtle nesting as light intensity increased. Light has been significantly increasing on mainland nesting beaches between 1992 and 2021 except for temporary declines. Island beaches historically had lower light pollution, but there was a sudden increase of light starting in 2014 that continued through 2021, except for the precipitous decline in 2020 during the Covid 19 pandemic. Light pollution on past nesting beaches has now approached levels that may be too polluted and discourage nesting. The impacts of the increased light pollution on nesting density and hatchling survival of hawksbill, Eretmochelys imbricata, and green turtles, Chelonia mydas, is likely negative.

Assessing spatial impacts of historical pulp mill effluent on trophic dynamics in a coastal marine ecosystem using stable isotope (δ13C and δ15N) analysis.

Boat Harbour, Nova Scotia was a tidal estuary that was converted into a wastewater treatment facility for pulp mill effluent in 1967. Treated effluent from Boat Harbour was discharged into the coastal Northumberland Strait, contributing significant nutrient and freshwater inputs into the coastal environment, potentially impacting local biogeochemistry and ecosystem structure. This study used stable isotope analysis of carbon (δ13C) and nitrogen (δ15N) of representative taxa to assess spatial variability in nutrient sources and trophic dynamics. Results identified stable isotope variation with depleted δ13C and δ15N values in taxa near Boat Harbour. Blue mussel (Mytilus edulis) and mummichog (Fundulus heteroclitus) were the most suitable bioindicators for identifying variation in nutrient sources. Stable isotope signatures in this study may be reflective of residual pulp mill effluent-derived nutrients, differences in marine versus terrestrial nutrient sources, and a pronounced coastal salinity gradient. The present study defined the baseline nutrient conditions of the Northumberland Strait and will be useful in assessing the effectiveness of remediation activities.