Preliminary assessment of marine debris pollution and coastal water quality on some beaches in Thanh Hoa province, Vietnam

Marine debris assessment gives information about their quantity, type, and composition, which provides data to help with their management and control. The authors conducted two surveys at three beaches at Sam Son, Hai Tien, Hai Hoa) in Thanh Hoa province in March 2020 and July 2020, respectively, during an inactive and active tourism period. A total of 3,803 waste units were collected for assessment, of which plastic waste accounts for more than 98%. The density of marine debris at the idle time of tourism ranged from 0.25–1.21 items/m2. But the active tourist season recorded from 0.52–1.4 items/m2. According to the Clean Coast Index (CCI), the cleanliness of beaches was grade from average clean (i.e., Hai Tien) to filthy (i.e., Hai Hoa). The plastic debris present at these beaches was mainly porous waste derived from fishing boats and food preservation foam boxes. The results also showed that the marine debris was composed of 77% polystyrene (PS), 17% polypropylene (PP) and 6% high-density polyethylene (HDPE). The water parameters were lower than the critical values during the study period according to the QCVN 10-MT:2015/BTNMT for both periods, which indicated the coastal water quality was still suitable for recreational activities.

U.S. beach water quality monitoring

Coastal water quality is an important factor influencing public health and the quality of our nation’s beaches. In recent years, poor water quality has resulted in increased numbers of beach closures and corresponding negative impacts on tourism. This paper addresses some of the issues surrounding the management challenge of coastal water quality, in particular, beach water quality monitoring. For this effort, data on beach water quality monitoring activities conducted by states were assessed and synthesized. In total, 29 states were surveyed: 16 reported information for seawater; six reported for freshwater only; eight reported for both seawater and freshwater. Thresholds for advisories and closure vary nationally; however, all 29 states have established an online presence for their monitoring programs and display advisories and closures in real time, most often on spatial information (GIS) portals. Challenges in monitoring, prediction, and communication are assessed and discussed. Based on this assessment, the committee offers the following recommendations, as detailed in the text: • Standardization of water quality data and the distribution medium; • Enhanced public access to water quality monitoring data; • Consistent thresholds for swim advisories; • Water quality regulation reviews with stakeholder participation; • Enhanced predictive models incorporating rapid testing results; • Holistic water quality monitoring that includes indicators beyond fecal indicator bacteria; • Managing contaminants of emerging concern through identification, monitoring and control; and • Funding for water quality monitoring and reporting -- from federal, state, and local governments.

The role of soils in regulation of freshwater and coastal water quality

Water quality regulation is an important ecosystem service function of soil. In this study, the mechanism by which soil regulates water quality was reviewed, and the effects of soil management on water quality were explored. A scientometrics analysis was also conducted to explore the research fields and hotspots of water quality regulation of soil in the past 5 years. This review found that the pollutants entering the soil can be mitigated by precipitation, adsorption and desorption, ion exchange, redox and metabolic decomposition. As an optimal substrate, soil in constructed wetlands has perfect performance in the adsorption and passivation of pollutants such as nitrogen, phosphorus and heavy metals in water, and degradation of pesticides and emerging contaminants. Mangrove wetlands play an important role in coastal zone protection and coastal water quality restoration. However, the excessive application of agricultural chemicals causes soil overload, which leads to the occurrence of agricultural non-point source pollution. Under the dual pressures of climate change and food insecurity in the future, developing environmentally friendly and economically feasible sustainable soil management measures is crucial for maintaining the water purification function of soil by relying on the accurate quantification of soil function based on big data and modelling. This article is part of the theme issue ‘The role of soils in delivering Nature's Contributions to People’.

Assessment of Water Quality Along the Southeast Coast of India During COVID-19 Lockdown

The COVID-19 pandemic has affected the entire world and has had a devastating impact on both lives and livelihoods in India. The only way to defeat the rapid spread of COVID-19, is to shut down socio-economic activities and to maintain minimal human interaction with the implementation of a lockdown. Such lockdowns have manifested in a pollution curtailment in almost all spheres of the planet, including in marine pollution. Quantifying this decrease in pollution levels enables the scientific community to assess the contribution of anthropogenic (especially non-essential) activities to global/regional pollution levels. This paper aims to study the impact of the stringent lockdown period (phase 1 and 2) on coastal water quality along the Chennai coast of India, by analyzing suspended matter concentration (SPM), a key element of water quality and diffuse attenuation coefficient, Kd(490), using LANDSAT-8 Operational Land Imager (OLI) data. LANDSAT-8/OLI, L1TP scenes were subjected to radiometric calibration and atmospheric correction to derive surface reflectance values from raw digital numbers using ACOLITE software and a brief insight has been given for the Dark Spectrum Fitting algorithm used in ACOLITE. SPM concentration decreased by 15.48 and 37.50% in the Chennai and Ennore ports, respectively, due to minimal vessel movement and cargo handling. The stringent lockdown led to the operation of fewer thermal plant units, thus less fly ash was emanated, resulting in a 28.05% reduction in SPM levels over Ennore creek. As industrial and commercial activities subsided, the city’s water bodies became clearer than they were just a fortnight prior to the lockdown, with a reduction of 22.26% of SPM in Adyar and 33.97% in Cooum riverine estuaries. Decrease in Kd(490) showed a positive relationship with SPM and thus improved coastal water quality because of the reduction of SPM during this period. The variations in PM2.5 and PM10 concentrations were studied using National Air Quality Monitoring Programme (NAMP) data and reduced levels in particulate matter concentration (PM2.5 and PM10) for the Adyar residential area (24.38 and 28.43%) and for the Nungampakkam commercial area (36.09 and 67.18%) were observed. A significant reduction in PM2.5 concentration (45.63%) was observed in the Ennore-Manali Industrial region.