Aquatic Environmental Assessment Research Articles

A high-quality chromosome-level genome assembly of the Chinese medaka Oryzias sinensis

Oryzias sinensis, also known as Chinese medaka or Chinese ricefish, is a commonly used animal model for aquatic environmental assessment in the wild as well as gene function validation or toxicology research in the lab. Here, a high-quality chromosome-level genome assembly of O. sinensis was generated using single-tube long fragment read (stLFR) reads, Nanopore long-reads, and Hi-C sequencing data. The genome is 796.58 Mb, and a total of 712.17 Mb of the assembled sequences were anchored to 23 pseudo-chromosomes. A final set of 22,461 genes were annotated, with 98.67% being functionally annotated. The Benchmarking Universal Single-Copy Orthologs (BUSCO) benchmark of genome assembly and gene annotation reached 95.1% (93.3% single-copy) and 94.6% (91.7% single-copy), respectively. Furthermore, we also use ATAC-seq to uncover chromosome transposase-accessibility as well as related genome area function enrichment for Oryzias sinensis. This study offers a new improved foundation for future genomics research in Chinese medaka.

Comparison of multi-temporal and multi-methodical aquatic environmental assessments (on the example of the Pripyat River for 1999 and 2022)

The article uses the example of the Pripyat River to examine the methodological features and conditions for comparing multi-temporal and multi-methodological (obtained by different methods) assessments of the ecological state of the aquatic environment. Thus, when comparing the current ecological state (for 2022) of the Prypiat River, obtained by the statistical criterion (SC) method with the ecological state of the river in 1999, obtained by the method of aquatic plant groups (APG), it is proposed to form virtual standards of the SC method on the basis of reference sites of previous assessments of the ecological state of the river (1999). A comparison of the ecological state of the Pripyat River in 2022 and 1999 showed significant changes in the structure of water quality in 2022 compared to 1999, namely a decrease in dirty areas and an increase in moderately polluted and clean areas. The study confirms the validity of the proposed method of comparing multi-temporal and multi-methodological aquatic environmental assessments.

Fish Biomonitoring and Ecological Assessment in the Dianchi Lake Basin Based on Environmental DNA

Fish are among the main target groups when conducting biomonitoring and ecological assessment of aquatic environments. Environmental DNA (eDNA) metabarcoding provides a unique opportunity to enhance biomonitoring throughput, precision, and standardization. However, few fish monitoring studies based on eDNA metabarcoding have been conducted at the basin scale. Taking Dianchi Lake and the three inflowing rivers (Panlong River, Baoxiang River, and Chai River) as research objects, this study monitored fish diversity via eDNA metabarcoding, and the Fish Index of Biological Integrity (F-IBI) was constructed and applied for the ecological assessment of the aquatic environment. Here, we detected 41 species belonging to 9 orders, 15 families, and 35 genera in the sampling areas, including 17 native fish species such as Hemiculter leucisculus, Cyprinus carpio, and Silurus soldatovi. Distinct diversity patterns were observed among Dianchi Lake and the three inflowing rivers. Particularly, the fish diversity of Panlong River was richer than that of Dianchi Lake, Baoxiang River, and Chai River. Water temperature (WT), chemical oxygen demand (COD), total nitrogen (TN), and total phosphorus (TP) significantly influenced the distribution of fish communities in most sampling sites of the Dianchi Lake basin (p < 0.05). Moreover, according to the F-IBI assessment system, 25% of the sampling sites were defined as ‘fine’ or above, and 75% were ‘impaired’ or below. This study provided insights into the ecological restoration and precise management of the aquatic environment of the Dianchi Lake basin.

Toxicity effects of microplastics and nanoplastics with cadmium on the alga Microcystis aeruginosa.

The extensive spread of microplastics (MPs) and nanoplastics (NPs) in the aquatic environment has attracted widespread attention. The toxicity of cadmium (Cd) combined with microplastics (MPs) and nanoplastics (NPs) toward freshwater algae Microcystis aeruginosa (M. aeruginosa) was investigated to evaluate the environmental behavior of the Cd complexation in fresh water. Cd alone has the highest toxicity to algae. Both MPs and NPs also have a negative effect on the growth of algae as individual components due to their adsorption of nutrients and disruption of the alga's activity in a single MPs/NPs system. Compared with the single system, the toxicity of compound pollution including MPs + Cd and NPs + Cd becomes stronger, which presents a synergistic effect. In the presence of NPs, more extracellular polymeric substances (EPS) appeared, which helped to reduce the toxic effect on the algal cells. Moreover, MPs/NPs + Cd stimulate the production of microcystin-LR (MC-LR) under different treatments. Overall, the aquatic environmental assessment shows potentially elevated risks associated with combined MPs/NPs with Cd, which should be considered.

A Mini-review of the Toxicity of Pollutants to Fish Under Different Salinities.

In recent years, with the development of the global economy, water pollution has increased. Pollutants migrate, accumulate, and diffuse in aquatic environments. Most of the pollutants eventually enter aquatic organisms. The accumulation of pollutants affects the development and reproduction of organisms, and many pollutants have teratogenic, carcinogenic, and/or mutagenic effects. Aquatic organisms in estuaries and coastal areas are under pressure due to both salinity and pollutants. Among them, salinity, as an environmental factor, may affect the behavior of pollutants in the aquatic environment, causing changes in their toxic effects on fishes. Salinity also directly affects the growth and development of fishes. Therefore, this paper focuses on metals and organic pollutants and discusses the toxic effects of pollutants on fish under different salinities. This research is of great significance to environmental protection and ecological risk assessment of aquatic environments.

Developing prokaryotic water quality indicators

Despite the importance of prokaryotes in aquatic ecosystem and their predictable diversity patterns across space and time, biomonitoring tools relying on prokaryotes are widely lacking. Using metabarcoding, as well as other molecular methods, we were able to identify multiple prokaryotic descriptors and illustrate their reliability and advantages in aquatic environmental assessment. Multivariate statistical and machine learning methods combined with variation coefficient and overall prevalence of taxonomic groups were used to detect possible biological indicators among prokaryotes for various anthropogenic pressures, i.e. acidification, eutrophication and faecal contamination in aquatic environments. In addition, text mining approaches provide powerful alternatives for sequence based status classification and source tracking of contaminants. While these individual sequencing based indicator approaches seem to be powerful, alpha and beta diversity indices provide so far minor precision in ecological status classification. Reasons are the often non-linear association between prokaryotic alpha and beta-diversity with environmental gradients as indicated by first modeling attempts. Still, our results suggest that the limitations in reliably describing reference communities and developing general and robust classification systems for water quality assessment based on prokaryotic sequencing data can be overcome by extensive training data.

The importance of open science for biological assessment of aquatic environments.

Open science principles that seek to improve science can effectively bridge the gap between researchers and environmental managers. However, widespread adoption has yet to gain traction for the development and application of bioassessment products. At the core of this philosophy is the concept that research should be reproducible and transparent, in addition to having long-term value through effective data preservation and sharing. In this article, we review core open science concepts that have recently been adopted in the ecological sciences and emphasize how adoption can benefit the field of bioassessment for both prescriptive condition assessments and proactive applications that inform environmental management. An example from the state of California demonstrates effective adoption of open science principles through data stewardship, reproducible research, and engagement of stakeholders with multimedia applications. We also discuss technical, sociocultural, and institutional challenges for adopting open science, including practical approaches for overcoming these hurdles in bioassessment applications.

Spatiotemporal variations of total suspended matter in complex archipelagic regions using a sigmoid model and Landsat-8 imagery

Total suspended matter (TSM) is an important parameter of ocean water quality and for aquatic environmental assessment. The Zhoushan Islands are near the estuarine and coastal regions of the Yangtze River and Qiantang River and TSM occurs at very high concentrations and in long-term suspended states. The distribution and variation of TSM in the Zhoushan Islands has great impacts on its coastal water quality and activities such as ferry services, fisheries, and tourism. Based on Landsat-8’s blue and near-infrared bands, this study developed a sigmoid TSM inversion model that was more accurate and robust than the other common linear and exponential models. We also checked three types of atmospheric correction models, FLAASH, 6S, and ACOLITE and determined that ACOLITE is better than the other two methods when using Landsat-8 in ocean color in estuarine and coastal regions. The sigmoid model was then applied to a series of Landsat-8 images covering the Zhoushan Islands from 2013 to 2018, and the image-derived results show that TSM absorption coefficients in the Zhoushan Islands are extremely high and range from 0.26 to 444.29 m−1 with a mean of 113.14 m−1. Furthermore, they have a clear downward gradient from the Hangzhou Bay to the open sea. In addition, the TSM concentrations in winter are usually much higher than those in summer. Our results indicate that TSM spatiotemporal variations in the Zhoushan Islands are not only controlled by many natural environmental factors, such as riverine discharge, but are also significantly influenced by many human activities such as transportation, tourism, and fisheries.

Wind measurements using a LIDAR on a buoy

ABSTRACT LIDAR technology is a promising alternative for the measurement of winds, requiring less maintenance and lower costs than meteorological towers. They are capable of remotely profiling winds by means of an infrared laser, which is backscattered by aerosols and particles carried by the air. The LIDAR can be assembled on fixed or mobile platforms. When installed on platforms such as moored buoys, the motion caused by waves must be evaluated and corrected. This study describes the use of a mechanical system and analytical methods for the motion compensation of a buoy-mounted LIDAR. A 24-hour experiment was conducted on Furnas Hydroelectric Reservoir to test the mechanical system, evaluate residual motions, and assess the winds. Correction algorithms for the horizontal wind speeds were applied using pitch and roll measurements, provided by an inertial sensor. Analyses demonstrate that horizontal wind speed errors are negligible for buoy inclinations of less than 20 degrees. The buoy-mounted LIDAR represents an economical solution for wind profiling and resource assessment of aquatic environments.

Effects of Long-Term Anthropogenic Disturbance on the Benthic Episammic Diatom Community of an Ancient, Tropical Lake.

Habitat homogenization, nutrient enrichment and loss of biodiversity are broadly recognized as the consequences of human activity in aquatic systems. Diatoms (Bacillariophyceae) are frequently used in aquatic environmental assessment and impact monitoring, but in unique habitats dominated by endemic taxa, traditional approaches may not be appropriate. We examined the impacts of long term anthropogenic impacts upon the littoral episammic diatom community around the town of Soroako, located on Lake Matano, an ancient tropical lake. Lake Matano is located on central Sulawesi Island, Indonesia, and socio-economic conditions are typical of developing nations. Although differences in nutrient concentrations were undetectable with field-based spectroscopy approaches, mean Shannon diversity was decreased in association with proximity the town-site. However, mean ß-diversity was maintained despite several decades of shoreline modification at Soroako. Elevated abundances of early-successional diatom taxa in the disturbed area drove differences between areas immediately offshore of Soroako and those farther away. These findings suggest that increased physical disturbance and TSS loads around Soroako, rather than increased nutrient loading, influenced shifts in the diatom community. These results suggest that microscopy-based biomonitoring approaches are sensitive indicators of environmental modification that could be useful in areas where access to cutting-edge analytical equipment is limited.

Aquatic environmental assessment of Lake Balaton in the light of physical-chemical water parameters.

One of the issues of the Hungarian Water Management Strategy is the improvement and upgrading of the water of Lake Balaton. The Water Framework Directive (WFD) specifies and sets forth the achievement of the good ecological status. However, the assessment of the water quality of the lake as a complex system requires a comprehensive monitoring and evaluation procedure. Measurements were carried out around the Lake Balaton at ten different locations/sites and 13 physical-chemical parameters were monitored at each measurement site.For the interpretation of the water chemistry parameters the Aquatic Environmental Assessment (AEA) method devised by authors was used for the water body of the Lake Balaton. The AEA method can be used for all types of the water bodies since it is flexible and using individual weighting procedure for the water chemistry parameters comprehensive information can be obtain. The AEA method was compared with existing EIA methods according to a predefined criterion system and proved to be the most suitable tool for evaluating the environmental impacts in our study.On the basis of the results it can be concluded that the status of the quality of studied area on the Lake Balaton can be categorized as proper quality (from the outcome of the ten measurement sites this conclusion was reached at seven sites).

Methodology development on aquatic environmental assessment

The Water Framework Directive aims at reaching the good ecological status of the surface and ground water bodies (László et al. Microchem J 85(1):65-71, 2007). The paper deals with quality evaluation of waters with special focus on the water chemistry parameters as defined in the Water Framework Directive and pertaining legal regulations. The purpose of this paper is to devise a quantitative type of water quality assessment method which could provide rapid, accurate, and reliable information on the quality of the surface waters by using water chemistry parameters. Quality classes have been defined for every water chemistry parameter in light of the legal limit values of the water parameters. In addition to this, weight indices were calculated on the basis of the outcome of the paired comparison of water chemistry parameters and normalized matrix. This was followed by the parametric level analysis of the water chemistry parameters, and finally, the aquatic environment index (AEI) was calculated, which provided general information on the quality of water regarding the water chemistry parameters. The method was illustrated on Lake Balaton, Hungary in which case water samples taken from Balatonfüred City lake area were analyzed and evaluated with the method devised.

Toxicological Impacts of Gas flaring and Other Petroleum Production Activities in Niger-Delta Environment

In this study, the concentrations of inducers of environmental toxicity such as heavy metals and polycyclic aromatic hydrocarbon and biomarkers of environmental toxicants such as oxidative stress enzymes/compounds and liver function enzymes were determined. These parameters were used to assess the pollution status of some Niger-Delta areas; Ebocha/Omoku, Abacheke/Egbema, and Okwuzi/Ohaji, with the aid of two indicator species: cat fish (Ictalurus punctatus) and snakehead fish (Channa argus) from three different water sources; Ebocha/Omoku river, Abacheke river and Okwuzi creek all of which are within the area of oil exploration and production activities in Nigeria. The control fish and water samples were collected from Otamiri River within the Federal University of Technology, Owerri, Nigeria, with no known oil exploration and production activity. The results obtained indicated significant (p < 0.05) differences between the exploited and the unexploited environment and the need to incorporate biochemical markers in environmental impact assessment of aquatic environments to complements the classical chemical monitoring.

A critical review of approaches to aquatic environmental assessment

As demands on aquatic resources increase, there is a growing need to monitor and assess their condition. This paper reviews a variety of aquatic environmental assessments, at local, national, international and global scales and finds confusion in the terminology used to describe assessments. In particular the terms ‘ecosystem’ and ‘integrated’ are often misused resulting in lack of clarity. Therefore, definitions of some assessment terminology are suggested, consolidating existing proposals and simplifying future applications. A conclusion from the review is that a new classification system is required. The categorisation system proposed builds on preliminary work of the International Council for the Exploration of the Sea (ICES). Assessment classification is based on the environmental components considered, methodologies and nature of the linkages between components, and the inclusion or exclusion of socio-economic factors. The assessment terminology and categorisation system provided could in future simplify the way that assessments are defined and used to inform development of management strategies.

Perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA) and their salts Scientific Opinion of the Panel on Contaminants in the Food chain.

Perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA) and their salts Scientific Opinion of the Panel on Contaminants in the Food chain.

Phototaxis index of Daphnia carinata as an indicator of joint toxicity of copper, cadmium, zinc, nitrogen and phosphorus in aqueous solutions

An orthogonal design method was used for examining the responses of Daphnia carinata to 16 combination mixtures of copper, cadmium, zinc, nitrogen and phosphorus in synthetic solutions. Phototaxis index ( I p ), mobilization inhibition percentage (MIP) and mortality percentage (MP) were used as test endpoints for toxicity assessment. The results show that Cu and Cd were the dominant toxicants that affected the D. carinata in the test solutions. However, the contribution of nitrogen, relative to other components, to the overall toxicity to D. carinata could increase over time. It was found that three toxicity parameters ( i.e . I p , MIP and MP) used in this study were significantly interrelated (at p < 0.003 level). Cluster analysis also indicates that there was a general agreement between the toxicity indicated by I p and the universally accepted test endpoints (MIP or MP); MIP and MP represent the universally accepted test endpoints, i.e . mobilization inhibition and mortality. These results suggest that the phototaxis index of D. carinata is an appropriate test endpoint for toxicity testing of environmental samples. This has implications for developing rapid, non-destructive bioassays for ecotoxicological assessment of aquatic environments.

Characteristics of six cladocerans in relation to ecotoxicity testing

Investigation was made to compare some biological characteristics relevant to ecotoxicity testing among six cladoceran species, including Daphnia magna, Daphnia carinata, Daphnia pulex, Ceriodaphnia quadrangular, Bosmina longirostris, and Simocephalus vetulus. The results show that D. carinata had advantages over other cladoceran species for being used as a test organism, particularly for ecotoxicological assessment of aquatic environments in tropical and subtropical areas. D. carinata had similar body size and total number of offspring per female to D. magna. However, D. carinata was more sensitive to the reference toxicant and had much shorter reproduction cycle than D. magna. D. carinata had similarity to D. pulex, C. quadrangular, S. vetulus and B. longirostris in terms of sensitivity to the reference toxicant and length of reproduction cycle. However, D. carinata was much larger in size and produced much more offspring per female than any of D. pulex, C. quadrangular, S. vetulus and B. longirostris. Among the investigated cladocerans, only the neonates (2- and 4-day-old) of D. carinata exhibited phototaxis that was sufficiently remarkable. The low among-generation variation in phototaxis index (Ip) of D. carinata and the close relationship between Ip and the concentration of the ISO standard toxicant (K2Cr2O7) appears to suggest that Ip can be used as an excellent test endpoint for ecotoxicity testing.

Aquatic environmental assessment of the top 25 English prescription pharmaceuticals

An environmental assessment is presented for the 25 most used pharmaceuticals in the National Health Service (NHS) in England in 2000. Predicted environmental concentrations (PECs) for the aquatic environment were calculated using conservative assumptions and all PECs exceeded 1 ng l −1. The calculation of predicted no-effect concentration (PNEC) based on aquatic toxicity data from the literature was possible for eleven of the pharmaceuticals. PNECs were predicted with ECOSAR for 12 of the remaining 14 but no data was available for two of the compounds. The PEC/PNEC ratio exceeded one for Paracetamol, Amoxycillin, Oxytetracycline and Mefenamic acid. Comparisons of the predicted concentrations of the compounds in sewage sludge based on either calculated sludge-water coefficients ( K d), octanol water coefficients ( K ow), acid base constants (p Ka) or environmental modelling revealed large variations. No toxicity data was available for the terrestrial environment and no assessment was made.

Modelling and assessment ofwaterquality indicators in a semi-enclosed shallow bay

Bohai Bay is a large, semi-enclosed shallow water basin located along the western region of the Bohai Sea in the north-eastern part of China. As a result of rapid economic development in the surrounding coastal hinterland, the water quality characteristics within Bohai Bay have been of growing concern in recent years. Details are given herein of an aquatic environmental assessment study undertaken to investigate the hydrodynamic and transport processes within the Bay using an integrated numerical modelling approach and tield measurements. 3-D numerical model was used to simulate the tide flow and 2 D model was deployed with moving boundary to simulate the water quality. In order to improve on the water quality characteristics in the near-shore coastal zone, an ocean disposal plan was also considered, with various scenarios being simulated using the 2-D model. From an analysis of data collected from the held measurements, it was found that both chemical and phytoplankton indicators were important in the assessment of the overall water quality of the Bay. The occurrence of red tides was also found to be closely linked to the composition of phytoplankton community.