The application of hydrogen peroxide (H₂O₂) as a management tool to control Microcystis blooms has become increasingly popular due to its short lifetime and targeted action. H₂O₂ increases intracellular reactive oxygen species resulting in oxidative stress and subsequently cell death. H₂O₂ is naturally produced in freshwater bodies as a result of photocatalytic reactions between dissolved organic carbon and sunlight. Previously, some studies have suggested that this environmental source of H₂O₂ selectively targets for toxigenic cyanobacteria strains in the genus Microcystis. Also, past studies only focused on the morphological and biochemical changes of H₂O₂-induced cell death in Microcystis with little information available on the effects of different H₂O₂ concentrations on growth, esterase activity and membrane integrity. Therefore, this study investigated the effects of non-lethal (40–4000 nM) concentrations on percentage cell death; with a focus on sub-lethal (50 μM) and lethal (275 μM; 500 μM) doses of H₂O₂ on growth, cells showing esterase activity and membrane integrity. The non-lethal dose experiment was part of a preliminary study. Results showed a dose- and time-dependent relationship in all three Microcystis strains post H₂O₂ treatment. H₂O₂ resulted in a significant increase in intracellular reactive oxygen species, decreased chlorophyll a content, decreased growth rate and esterase activity. Interestingly, at sub-lethal (50 μM H₂O₂ treatment), percentage of dead cells in microcystin-producing strains was significantly higher (p < 0.05) than that in non-microcystin-producing strains at 72 h. These findings further cement our understanding of the influence of H₂O₂ on different strains of Microcystis and its impact on membrane integrity and metabolic physiology: important to future toxic bloom control programmes.

In less than two decades, the global tourism industry has overtaken the construction industry as one of the biggest polluters, accounting for up to 8% of global greenhouse gas emissions as reported by the United National World Trade Organization (UNWTO 2018). This position resonates the consensus of the United Nations Framework Convention on Climate Change (UNFCCC). Consequently, research into the causal link between emissions and the tourism industry has increased significantly focusing extensively on top earners from the industry. However, few studies have thoroughly assessed this relationship for small island economies that are highly dependent on tourism. Hence, this study assessed the causal relationship between CO₂ emissions, real GDP per capita (RGDP) and the tourism industry. The analysis is conducted for seven tourism-dependent countries for the period 1995 to 2014 using panel VAR approach, with support from fully modified ordinary least square and pooled mean group–autoregressive distributed lag models. Unit root tests confirm that all variables are stationary at first difference. Our VAR Granger causality/block exogeneity Wald test results show a unidirectional causality flowing from tourism to CO₂ emission, RGDP and energy consumption, but a bi-directional causality exists between tourism and urbanization. This implies that in countries that depend on tourism, the behaviour of CO₂ emission, RGDP and energy consumption can be predicted by the volume of tourist arrivals, but not the other way around. The impulse response analysis also shows that the responses of tourism to shocks in CO₂ appear negative within the 1st year, positive within the 2nd and 3rd years but revert to equilibrium in the fourth year. Finally, the reaction of tourism to shocks in energy consumption is similar to its reaction to shocks in RGDP. Tourism responds positively to shocks in urbanization throughout the periods. These outcomes were resonated by the Dumitrescu and Hurlin causality analysis where the growth-induced tourism hypothesis is validated as well as feedback causality observed between tourism and pollutant emission and urbanization and pollutant emission in the blocks over the sampled period. Consequently, this study draws pertinent energy and tourism policy implications for sustainable tourism on the panel over their growth trajectory without compromise for green environment.

Plastics have become strong environmental stressors of coastal marine ecosystems. Their introduction into the marine ecosystem is subjected to different mechanisms, including the inadequate disposal of solid waste and dumping of wastewater. In addition, their chemical composition makes them resistant to variables such as temperature and salinity of water. These polymers are degraded and fragmented mainly due to the action of the waves, which results in the formation of smaller particles called microplastics. Microplastics are characterized by being persistent in the environment due to their low biodegradation, and although they have a maximum size of 5 mm, there is a wide range of sizes suggested by different authors. According to their use, microplastics can be classified as primary when they are recognized at first sight, and as secondary, when they are gradually divided. Microplastics have become a potential risk to the health of marine species due to their small size, and the risk to human health due to their persistence through trophic chains is alarming. Given the potential impact these materials would have in the biota, and the need to assist the different regulatory agencies to develop political acts on the proper management and disposal of microplastics, the aim of this work was to identify different research carried out at international level on established methodologies for studies of identification and quantification of microplastics, bacterial communities, and contaminants adhered to microparticles. Given the above, some methodologies have been identified and used in various studies for the identification and quantification of these materials on beaches. It should be noted that in different countries, there has been an increase in research related to contamination by microplastics on beaches, in which bacterial communities attached to these plastic particles have been also identified. Likewise, not only the risks and threats have been determined for marine species but also for the health of people who frequent tourist places such as beaches.

Freshwaters are highly vulnerable to pollution since they act as immediate sinks for the consequences of human activity always associated with the danger of accidental discharges. Heavy metals constitute a core group of aquatic pollutants and additional concentrations of these metals accumulate in the aquatic ecosystems as a result of land-based activities. Fish mostly tend to bioaccumulate heavy metals, and humans can be at great risk, sometimes even lethal, through contamination of the food chain. An attempt has been made in the present investigation to determine the acute toxicity of lithium and its toxicological effects on survival, physiological, haematological and biochemical parameters of the widely consumed spotted sneak head Channa punctatus and Nile Tilapia Oreochromis niloticus. Short-term acute toxicity tests were performed by exposing the test species to different concentrations of lithium chloride. The results showed that the normal respiratory activity of the fish was significantly affected and there was a depression in the metabolic rate at the end of 24, 48, 72 and 96h exposure. Appreciable decline changes occur in haematological parameters and biochemical profiles of the fish. This study reflects the extent of the toxic effects of lithium and the metal-induced cumulative deleterious effects at various functional levels in the widely consumed freshwater fish, Channa punctatus and Oreochromis niloticus.

Cryptosporidium can transport from the soil to the water resulting in the contamination of the surrounding water bodies. However, there are few pieces of research on the transport of Cryptosporidium from the slope soil to the surrounding water. The experiment simulated the transport of Cryptosporidium surrogate, carboxylate YG polystyrene, influenced by the rainfall intensity, rainfall pattern, soil type, and land slope, from the soil to water, to understand the transport of Cryptosporidium surrogate under these different conditions. The results showed that the transport of Cryptosporidium surrogate was affected by the surface runoff factors, that is, the high rainfall intensity, high rainfall frequency, steep slope and high sand content soil that resulted in the high transport of the Cryptosporidium surrogate.

The present study was aimed to characterize the bacterial isolate DDI(I)1 isolated from the rhizospheric soil of Ocimum grown in New Delhi (India). The isolate exhibited multiple plant growth promoting activities namely ammonia production, production of phytohormones, hydrogen cyanide, solubilization of minerals, tolerance against heavy metals, etc. The isolate was morphologically and biochemically characterized and it was found that DDI(I)1 belongs to genus Pseudomonas. Further, 16S rRNA sequencing revealed that the isolate shared 99% homology with Pseudomonas fluorescens.

Recently, facing situations of insufficient energy and harsh environmental conditions, new-energy vehicles begin to enter people’s lives. But considering many factors such as price and market acceptance development of new-energy automobile market must not lack government incentives. In recent two years, the government’s subsidy for green technology development to new-energy automobile enterprises has entered the post-subsidy era. To explore the sustainable development of new-energy automobile enterprises, Foton automobile was selected as the research object and the scale of government subsidy for green technology development to Foton automobile was clearly defined, the performance was analyzed by using multiple regression method. Results show that government subsidy and tax return for green technology development have a positive effect on Foton automobile’s performance, environmental regulation stringency has a significant positive moderating effect. Referring to the conclusions, some suggestions were put forward for Foton automobile’s future development and the development of newenergy automobile industry.

The source region of the Yellow River, located in the north-eastern edge of the Qinghai-Tibet Plateau, is an important water conservation region and ecological barrier of the Yellow River. In this paper, based on remote sensing technology, multi-period Landsat remote sensing images in the source region were taken as the main information source. With the assistance of field investigation, we monitored the spatial and temporal changes of desertification in the source region from 2000 to 2019. The results show that the area of desertification in the source region has accounted for 9.36% of the total area, of which the light desertification land is the major portion. The desertification is mainly distributed between the southern margin of Madoi Valley basin and the northern margin of Heihe Valley basin, and is distributed on the river valleys, lakesides, ancient rivers and piedmont proluvial fan, showing the form of patches, sheets and belts. The growth rate of desertification in the source region was 87.47% from 2000 to 2010. With a high growth rate, the process of desertification was represented by the rapid spread of desertification. From 2010 to 2019, the growth rate of desertification was 37.32%, which was relatively slow. But the moderate desertification land maintained a straight linear growth trend, showing an increasing trend of desertification degree. Through the analysis of the driving factors of desertification in the source region of the Yellow River, this paper argues that the special geographical location, climatic factors, rodent damages and human activities are the main causes of desertification.

The prosperity of the entire biotic community depends on two broad components of nature; land and water. The basaltic rock is known to have poor storage and transmission capability. It gets fully saturated during monsoon but a situation of rejected recharge results in post-monsoon and early summer months. These aquifers also drain naturally due to high water table gradient formed by sloping and undulating topography. The available and new groundwater recharge potential zones can better augment by adopting a scientific and multi-sectoral approach for making the future plan. The study area encompasses Manganga River basin, bounded between Lat. 17°54’ N to 17°00’ N and Long. 74°27’ E to 75°31’ E. The study area is in basaltic terrain with undulating topography. The spatial and non-spatial data generated based on various thematic maps such as geology, lineament density, geomorphology, slope, drainage buffer, land-use land-cover, soil texture and soil erodibility have been prepared using satellite data. The groundwater prospects maps generated by overlay analysis of the spatial thematic maps were grouped into five classes and their distribution are: very good/excellent, good, moderate, poor and very poor. The results show that a major portion of the study area falls in the category ‘poor’ followed by ‘very poor’. Based on the outputs derived from groundwater recharge potential zones, an action plan for watershed development in the study area has been suggested like the development of percolation/water retention ponds at the identified sites and tube/bore/open wells along the dense lineament zones. The aspect related to conjunctive use, groundwater legislation, the involvement of NGO’S, women and community participation, mass awareness, adoption of advanced irrigation system etc. will play an important role in conserving and developing the precious water resources.

The study was conducted to investigate the presence of antibiotic resistant bacteria in guava, sold in the local markets of Patna. A total of twenty five fresh samples of guava were collected from five different market places in Patna city. Several microbiological tests were performed to assess the growth and type of bacteria. The colonies were isolated and identified as isolate 1 and 3 (identical to Staphylococcus spp.), isolate 2 (identical to Escherichia spp.) and isolate 4 and 5 (identical to Bacillus spp.) based on their cultural, morphological, Gram’s staining and biochemical characteristics. Antibiotic susceptibility tests were conducted to detect their actual resistance capability. In the present study, S1 and S3 were found resistant to ampicillin, chloramphenicol, ofloxacin and intermediate to gentamycin while S2 was found resistant to ampicillin, chloramphenicol, gentamycin, ciprofloxacin, cephalexin and intermediate to ofloxacin. The isolates S4 and S5 were found sensitive to gentamycin, intermediate to chloramphenicol and resistant to ciprofloxacin. Results of this study showed that the guava samples obtained from different markets of Patna possess multidrug resistant bacteria.