Deterioration of water and soil quality, poor infrastructure facilities and improper maintenance are the major factors that govern aquaculture growth and production in major part of India. In the present study aims to identify the suitable land for aquaculture growth and suggest the sustainable practice to improvise the growth of aquaculture in study region. With use of analytical hierarchy process (AHP) the various significant parameters such as geology, pH, salinity, soil media, slope, geomorphology, land use land cover, distance to water, settlement and road networks were analyzed and based on these characteristics, thematic maps were prepared. The results are revealed that, that 882.13 km² area was most suitable, 1264.88 km² area was suitable and 14.00 km² area was unsuitable for aquaculture in the study region. The study results will helpful to decision makers and to make a design plan for aquaculture growth in the study region.

Marine litter is a major global concern that is threatening marine ecosystems. This study assessed the meso-litter and microplastics density around Mauritius Island, South West Indian Ocean (SWIO) region. WIOMSA guidelines were used for meso-litter and microplastics sampling from October to December 2019 at 12 sites. A total of 1095 meso-litter items (weighing 1250 g) was sampled. Plastics were the most abundant litter category. ‘Shoreline and recreational activities’ were the main meso-litter source. Microplastics density was highest at the vegetation line (VL) zone. Fragments, mostly blue-coloured, were the most encountered type of microplastics, and polyethylene was the most prevalent polymer type. This study provides important baseline data which can be used by relevant authorities for more effective waste management strategies and awareness campaigns that will help further mitigate the marine litter problem in Mauritius, and to check the effectiveness of management measures in place.

Microplastic (MP) pollution in estuarine environments is poorly characterized globally, although they are extensive buffer regions between terrestrial, freshwater and seawater environments. This research aims to investigate MP pollution levels and variations of MPs abundance with tidal fluctuation. Fourteen samples were collected from the surface water of the Chao Phraya River Estuary, Thailand using the Manta net at flood and ebb tides. The average abundance of microplastics at flood tide was 5.16 × 10⁵ particles/km² and at ebb tide was 3.11 × 10⁵ particles/km². The abundance of microplastics in the estuary was directly related to the tidal fluctuation, creating an accumulation of microplastics in the study area. Polypropylene, polyethylene, and polystyrene were the most common polymers. The findings provide important information on the pollution status of microplastics in the Chao Phraya River Estuary and the variation of suspended microplastics with tidal fluctuation should be considered in future estuarine microplastic studies.

In the present study, we have assessed the degree of contamination of heavy metals (Cd, Cu, Pb, and Zn) in ten species of red and brown seaweeds, the seasonal variations in the concentration of metals, and the health risk due to the seaweeds. Overall metal concentrations for red and brown seaweeds followed the order Pb > Zn > Cu > Cd and Pb > Cu > Zn > Cd, respectively. Cd and Pb levels were found to be elevated in both the red and brown seaweeds. Multivariate statistical analysis revealed that the sources of Cd and Pb are mainly anthropogenic. Despite the high concentrations of the non-essential metals (Cd and Pb) in the seaweeds, the health risk assessment revealed that they have a lower hazard index. Hence, consumption of edible red and brown seaweeds from the Tuticorin coast may not pose health hazards in humans for the time being.

The global distribution of microplastic debris on the sea floor poses an increasing risk to marine organisms and ecosystems. Here, we present a distribution analysis of microplastics collected from eight marine multicores recovered from the Iceland continental shelf and surrounding areas at water depth between 241 and 1628 m. We report a total of 306 microplastics from the size range > 250 μm −5 mm, of which all were fibers. Microplastic numbers range between 0.119 and 0.768 per gram of dry sediments. In the analysis we assess the potential role of oceanic surface and bottom water currents, organic content, and sediment type on the distribution, deposition, and burial of microplastics in marine sediments. Our results provide the first record of microplastic pollution of marine sediments from the Iceland continental shelf and identify Atlantic Cod feeding and breeding grounds as potential hot spot for the accumulation of marine debris.

It has been 14 years since the world's largest Ulva bloom appeared in the Yellow Sea, China in 2007. Although it is clear that the Ulva bloom originates from the culture system of Porphyra yezoensis (Nori) in the southern Yellow Sea, how to control it is still little understood. Since overwintering banks played a crucial role in the development of spring population of green algae on the cultivation ropes, here, a promising method was presented to prevent the development of Ulva bloom by the inactivation of the overwintering banks of green algae on the P. yezoensis cultivation ropes during February and early March. Chlorine dioxide, an environment-friendly disinfectant was used as algaecide with dosage of no lower than 40 mg/L at the contact time of 1 min. The overwintering green algae gradually disappeared within two weeks after the treatment. Furthermore, the growth of spring population of green algae on the cultivation ropes was effectively inhibited for at least eight weeks, which contribute to prevent the formation of floating populations during cultivation facilities collection. It was expected that the present method, if to be applied in the P. yezoensis cultivation areas in southern Yellow Sea, may mitigate the magnitude of the Ulva blooms in the Yellow Sea at a lower cost.

The Great Barrier Reef (GBR) is threatened by climate change and local pressures, including contaminants in nearshore habitats. This study investigated the combined effects of a GBR-relevant contaminant, the herbicide diuron, under current and two future climate scenarios on the coral Acropora millepora. All physiological responses tested (effective quantum yield (ΔF/Fm′), photosynthesis, calcification rate) were negatively affected with increasing concentrations of diuron. Interactive effects between diuron and climate were observed for all responses; however, climate had no significant effect on ΔF/Fm′ or calcification rates. Photosynthesis was negatively affected as the climate scenarios were adjusted from ambient (28.1 °C, pCO₂ = 397 ppm) to RCP8.5 2050 (29.1 °C, pCO₂ = 680 ppm) and 2100 (30.2 °C, pCO₂ = 858 ppm) with EC50 values declining from 19.4 to 10.6 and 2.6 μg L⁻¹ diuron in turn. These results highlight the likelihood that water quality guideline values may need to be adjusted as the climate changes.

Trace element pollution in the marine system is a global concern as the exposure of marine organisms to this pollution results in bioaccumulation and further transfer of the trace elements to humans through food chain. In the present study, the distribution of trace elements, namely chromium, cobalt, nickel, iron, copper, zinc, arsenic, cadmium, mercury, and lead, in gills, bone, liver, and muscle of eight commercially important fish collected along the southeast coast of India was analyzed using an inductively coupled plasma mass spectrometer. The liver was the main organ of accumulation for copper, zinc, arsenic, cadmium, and mercury; bone for chromium, cobalt, and lead; gills for copper; and muscle for arsenic and mercury. The concentration of toxic trace elements such as arsenic, cadmium, mercury, and lead in the edible portion of fish was lower than the recommended International Legislation limits, indicating that the fish of this region are safe for consumption.

Air pollution is a major global concern in urban areas and it is considered the greatest environmental risk to health. Nature-based solutions (NBS) can help improve air quality and reduce the urban heat island effect. The impacts of urban vegetation on air quality and ambient temperature depend on many factors, such as vegetation type, location, pollutants, climate conditions and topography. Therefore, the implementation of NBS needs to be tailored for each city. Within the context of the H2020 UNaLab project, the main objective of this work is to assess the potential of NBS to improve air quality across three European cities with different climates: (i) Eindhoven, The Netherlands; (ii) Tampere, Finland; and (iii) Genova, Italy. The WRF-CHEM model was applied for the hottest week in a present climate reference year. The baseline case (without NBS) and two NBS scenarios were simulated for each city. These scenarios (green roofs and green parks) were implemented in the model by modifying the land-use type and the emissions of the model grid cells. According to the model results, the city that least benefited from NBS was Tampere with an average reduction of 5% in surface temperature, and 1% in nitrogen dioxide (NO2) and ozone (O3) concentrations. Temperature-wise Genova and Eindhoven had similar results, approximately 6% reduction, while Genova showed the largest improvement in NO2 (12%). These results indicate that NBS are more effective in high temperature and high air pollution cities, such as Genova. Moreover, this study reinforces the importance of studying case-specific solutions, considering environmental characteristics and challenges.

The disinfecting properties of sun (heat and UV radiation) are adequate in warm sunny regions to rid beach sand of coronavirus particles, if present. Here we detail the mechanism of natural disinfection offered by the sun on coronaviral particles that may find their way onto beach sand. We conclude that heat and UV radiation generated by the sun destroy the virus infection ability.