Lotic Research Articles

The Relationship of Fish Functional Traits, Physicochemical Characteristics and Exotic Fish (Micropterus salmoides and Lepomis macrochirus)

An invasive species is defined as a biological species introduced, most often through human action, that causes direct harm, such as reducing or driving native species to extinction. This introduction can result in long-term changes to ecosystem structures and ultimately contribute to a decline in biodiversity within areas where it was not previously present. Thus, continuous monitoring and management are essential. This study examined the impact of two exotic species, largemouth bass (Micropterus salmoides) and bluegill (Lepomis macrochirus), on fish diversity in rivers across South Korea. Data from the “Stream Ecosystem Survey and Health Assessment” project, which was conducted along five major river basins between 2013 and 2021, were analyzed. The data were divided into three periods: 2013–2015, 2016–2018, and 2019–2021, covering a total of 960 sites. The results revealed that largemouth bass and bluegill were present at 360 sites (37.5%) from 2013 to 2015, 325 sites (33.9%) from 2016 to 2018, and 356 sites (37.1%) from 2019 to 2021. Additionally, when comparing sites where exotic fish were present with those where they were absent, the average number of native species was slightly higher in areas where these invasive species were present, yet the average Fish Assessment Index (FAI) value was lower. Statistically significant differences were observed in fish diversity, especially in trophic and tolerance traits. This study provides valuable insight into the impact of invasive species on South Korean river ecosystems and offers important information for developing future conservation and management strategies for biological resources.

Presence of microplastics during high rainfall events in the Cauvery River (South India): Ecological risk and cultural practices.

Rivers directly support the development of a region/country; however, globally, these aquatic regions are impacted by recent human activity. During a rainfall event, we monitored the baseline information on the spatial variability of microplastics (MPs) in the Cauvery River in South India. Forty surface water samples from two selected sites were collected between 27 September and 16 October 2022 during the commencement of monsoon which indicates 69 and 43 pieces L-1 of MPs, respectively. SEM and FTIR analysis on the surface morphotypes (cracks, grooves, pits) and elemental (Si, Ti, Mg, Cu, Ta) presence/adsorption of these elements' (in particle) surface indicates surface deformation of fibers, which is mainly due to external input/forces. Fragments of polymers establish a high degree of deterioration indicating its longer trajectory in the aquatic environment. The origin of extended fiber ranges between 631.65 and 5639.9µm, which is being associated with laundry activities for textiles, household items, and fishing gear. Toxicity and ecological risk assessment suggest significant degree of weathered MPs due to photo-oxidation process and aging owing to exposition of intense UV light. This research serves as a strong illustration of the multiple pressures from urban development and cultural practices that have a bigger influence on the river ecosystem like Cauvery River and regular monitoring.

Furry, Feral, Foe: Temporalizing Heath and Invasion on an English Chalk Stream.

This article explores framings of life, death, health, and invasion on an English chalk stream. It focuses on the ways in which these notions have been put to work in recent history, in relation to each other, and in relation to particular species and spaces. By 2019, narratives of a chalk stream in South-East England as a dead river expanded beyond retort to intermittent waterlessness. The river's death came to be framed as part of a wider ecology of chalk stream (ill)health, influenced by twenty-first century biodiversity conservation narratives and hauntological effects, which rendered deathly chalk stream futures present and requiring of human-action now. These narratives and effects conditioned a powerful sense of which non-human life belonged and counted, and which non-human life did not. Absent flagship chalk stream species, water voles, and efforts to resurrect them, were made synonymous with restoring the river itself to life and health. Contrarily, the ongoing presence of "invasive" American mink served as a continued reminder of the river's demise and death as a chalk stream. The resurrection of chalk streams to health relied on their being dispatched. Once considered to belong as extracted "lively capital" dominating the fur industry and later tolerated as feral escapees in the wild of the UK, American mink had been resituated and their history progressively obscured. Humans became manager-come-saviors of chalk streams, whose lost health was agreed and rendered visible through the ghostly image of the water vole that must be saved from the invasive foe, American mink.

Assessing the Water Quality and Its Influence on the Chlorophyll-a Concentration in the Karnaphuli River Estuary

The Karnaphuli river, essential for the economy and biodiversity of Bangladesh, faces increasing threat due to the proximity of industries, necessitating regular water quality monitoring to safeguard both environmental and economic interests. Hence, this study investigates the nutrient distribution and physicochemical parameters (pH, temperature, turbidity, dissolved oxygen, and electric conductivity) in relation to the chlorophyll a dynamics in the Karnaphuli river estuary during the monsoon season for evaluating water quality in the river estuary, stretching about 42 kilometres. Surface and deep-water samples have been collected from five different stations. Nutrients, chlorophyll concentration, and dissolved oxygen have been evaluated using a Continuous Flow Autoanalyzer, spectrophotometer, and DO kit, respectively, while electric conductivity, temperature, turbidity, and pH have been measured using a CTD tool. Spatial mapping and correlation analysis have been conducted as well. Temperature and pH values didn’t show much fluctuation within the sampling stations falling within the range of 29°C-31°C and 6.5-7.5, respectively. Positive correlation of pH with ammonia at surface water (r=92) indicates that the effluents of ammonia plants are the primary source of pH in river water. TSP plant effluent has been shown to cause turbidity, evident from the positive correlation between phosphate and turbidity both at surface and deep water (r=91). Increase in turbidity (562.1 NTU) resulted in a decrease in dissolved oxygen (3 mg/L), which poses a serious threat to the survival of aquatic life, including fish, in the river downstream. Decreased water quality at river downstream is evident by comparatively low chlorophyll presence of 1.5 μg/L. However, the shallow coastal region in the study area is indicative of a healthy aquatic ecosystem evident by the presence of high productivity indicated by high chlorophyll concentration of 8.9 μg/L, which is due to comparatively low levels of turbidity and also the water condition there met the standard DO for fisheries (>5mg/L). The findings underscore the critical importance of regular water quality monitoring in the Karnaphuli river to safeguard both the environment and economy of Bangladesh, urging collective action to mitigate the escalating threats posed by industrial activities and ensure the long-term sustainability of the river ecosystem. The Dhaka University Journal of Earth and Environmental Sciences, Vol. 13(1), 2024, P 91-104

Updated Fish Fauna of Karpuz and Ilıca Streams in Antalya Region: Species Diversity and Ecological Assessment

This research aims to provide an updated account of the fish fauna present in the streams Karpuzçay and Ilıca located in Antalya, southwestern Türkiye. The research was conducted through fish sampling at four strategically selected stations within these rivers, which were chosen for their high representativeness of the overall riverine ecosystem. The sampling took place in May 2023, primarily using the SAMUS 1000 portable electrofishing device to collect fish specimens. Records from Ege University Faculty of Fisheries Freshwater Fish Collection (EFSM), and the Zoological Collection of Recep Tayyip Erdoğan University (FFR) were also included in the study, along with published literature, to create an updated fish list for these two rivers. Our findings revealed the presence of multiple families, indicating a diverse fish community within these freshwater systems. Significantly, this study reports the presence of Tinca tinca (tench) in Karpuzçay Stream for the first time according to EFSM records, marking a noteworthy addition to the known fish fauna of the region. Karpuzçay and Ilıca rivers are critical components of the Antalya River Basin, contributing substantially to the area's ecological balance, economic activities, and cultural heritage. These rivers support a variety of aquatic and riparian habitats, which are essential for numerous species and local communities. Despite their importance, the rivers face numerous threats including pollution, habitat destruction, water extraction for agriculture, and the impacts of climate change. These pressures underscore the urgent need for effective conservation measures to safeguard the integrity and biodiversity of these river systems. This study not only updates the fish species list of the Karpuzçay and Ilıca rivers but also discusses the implications of these findings for the health and conservation of these aquatic ecosystems. By compiling and analyzing existing information alongside new data, I aim to provide a comprehensive overview of the rivers' biodiversity and the environmental factors influencing it. The discussion includes recommendations for conservation strategies to mitigate threats and promote the sustainable management of these vital freshwater resources.

Remote Sensing Estimation of CDOM for Songhua River of China: Distributions and Implications

Rivers are crucial pathways for transporting organic carbon from land to ocean, playing a vital role in the global carbon cycle. Dissolved organic carbon (DOC) and chromophoric dissolved organic matter (CDOM) are major components of dissolved organic matter and have significant impacts on maintaining the stability of river ecosystems and driving the global carbon cycle. In this study, the in situ samples of aCDOM(355) and DOC collected along the main stream of the Songhua River were matched with Sentinel-2 imagery. Multiple linear regression and five machine learning models were used to analyze the data. Among these models, XGBoost demonstrated a superior, highly stable performance on the validation set (R2 = 0.85, RMSE = 0.71 m−1). The multiple linear regression results revealed a strong correlation between CDOM and DOC (R2 = 0.73), indicating that CDOM can be used to indirectly estimate DOC concentrations. Significant seasonal variations in the CDOM distribution in the Songhua River were observed: aCDOM(355) in spring (6.23 m−1) was higher than that in summer (5.3 m−1) and autumn (4.74 m−1). The aCDOM(355) values in major urban areas along the Songhua River were generally higher than those in non-urban areas. Using the predicted DOC values and annual flow data at the sites, the annual DOC flux in Harbin was calculated to be approximately 0.2275 Tg C/Yr. Additionally, the spatial variation in annual CDOM was influenced by both natural changes in the watershed and human activities. These findings are pivotal for a deeper understanding of the role of river systems in the global carbon cycle.

Status of fishery resource management through an ecosystem approach in the several fishery management models in the Kampar River, Riau Province, Indonesia

The Kampar River's high fish diversity dramatically benefits the local community. However, overfishing threatens the river's fishery resources. Urgent and concerted management efforts, including local wisdom implementation, are crucial to address this pressing issue. Law Number 45 of 2009 concerning Fisheries mandates sustainable fishery resource management, primarily through an ecosystem-based approach. From January to June 2024, researchers conducted a study in the Kampar River area to assess the status of ecosystem-based fishery resource management across several management models. The research combined qualitative and quantitative methods, using purposive sampling to select 5-10 participants from each village. Following guidelines from the Directorate of Fish Resources, the study developed indicators for each domain and converted them into composite indicators using the 'flag modeling' technique. Data analysis showed that the Lubuk Larangan management model achieved the highest ecosystem-based fishery resource status, scoring 13,374 points (green). The individual auction system, communal auction system, and government regulations scored 13,168, 13,120, and 10,899 points respectively (yellow). These results highlight the effectiveness of local wisdom-based approaches in sustainable fishery resource management for the Kampar River ecosystem.

Change in Water Quality of the Vistula River During the Emergency Discharge of Untreated Wastewater

This paper presents an environmental analysis of the impact of an emergency discharge of untreated municipal sewage from the sewage system in Warsaw. This study was based on monitoring water quality in the Vistula River at stations located before and after the discharge site. Statistical analysis, including correlation analysis and Friedmann’s test, was performed for the data covering eight measurement stations and sixteen chemical parameters. The results confirm the negative impact on the water quality in the river, especially in the mixing zone. In the mixing zone, a statistically significant increase in pollution was found for TN, N-NO3−, N-NH4+, TP, P-PO43+, SS, EC, COD, and TOC. The results of the analysis show the self-cleaning capacity of the river ecosystem and illustrate the response to a sudden, excessive influx of pollution. The direct impact of the untreated sewage discharge was found on a section of the river 1200 m after the place of the failure. The good ecological status and drinking water standards are not met in the mixing zone. The supply of water to the people requires the use of highly effective physical and chemical treatment.

Study on the Function and Planning of Urban River Ecological Corridor

This study investigates the functions and planning principles of urban river ecological corridors, highlighting their vital role in urban ecosystems. Urban rivers, which include both waterways and riparian zones, provide essential ecosystem services such as habitat provision, temperature regulation, pollutant filtration, and flood mitigation. However, rapid urbanization has led to the degradation of these corridors, resulting in habitat fragmentation, reduced biodiversity, and compromised ecological integrity. The paper reviews global efforts and strategies for urban river restoration, emphasizing the significance of ecological methods and public participation in the planning process. A case study of the Yuhangtang River in Hangzhou, China, exemplifies various restoration approaches, including traditional flood control, ecological restoration, and landscape design, all assessed using a multi-criteria decision-making (MCDM) framework. The findings indicate that employing the MCDM tool can facilitate planning that integrates the functions of river ecological corridors. Additionally, plans that achieve a balance of ecological, economic, social, and aesthetic benefits are more likely to gain public acceptance.

Study on the Function and Planning of Urban River Ecological Corridor

This study investigates the functions and planning principles of urban river ecological corridors, highlighting their vital role in urban ecosystems. Urban rivers, which include both waterways and riparian zones, provide essential ecosystem services such as habitat provision, temperature regulation, pollutant filtration, and flood mitigation. However, rapid urbanization has led to the degradation of these corridors, resulting in habitat fragmentation, reduced biodiversity, and compromised ecological integrity. The paper reviews global efforts and strategies for urban river restoration, emphasizing the significance of ecological methods and public participation in the planning process. A case study of the Yuhangtang River in Hangzhou, China, exemplifies various restoration approaches, including traditional flood control, ecological restoration, and landscape design, all assessed using a multi-criteria decision-making (MCDM) framework. The findings indicate that employing the MCDM tool can facilitate planning that integrates the functions of river ecological corridors. Additionally, plans that achieve a balance of ecological, economic, social, and aesthetic benefits are more likely to gain public acceptance.

Quantitative study on the relationship between land use and land cover and diatom community in urban streams.

The study of the impact of urbanization on river ecosystems is an important part of constructing sustainable cities. How to quantitatively study the impact of urbanization on river ecosystems is the difficulty of urban ecological research. This study quantitatively investigated the effects of LULC on water quality and diatom assemblages in urban streams by correlation analysis, multivariate analysis, and path analysis. The results showed that (1) the percentage of LULC type in buffer 600m of reference stream sites is significantly different from that of urban stream sites. In reference sites, the average percentage of green was 94.2%, barren 3.3%, and impervious surface 2.5%. In urban upstream sites, the average percentage of impervious surface was 63.1%, green 32.8%, water 3.3%, and barren 0.8%. In urban downstream, the average percentage of impervious surface was 59.0%, green 36.5%, water 2.7%, and barren 1.8%. (2) One-way analysis results showed that water quality variables were significantly differences among the sites. The correlation analysis results indicated that LULC had a significant influence on water quality. Green had a significant negative correlation with high concentrations of NO3-N, NH4-N, and Cond. but positively correlated with MSUBST. RDA results showed that the selected water quality variables, MSUBST, and LULC types have a significant impact on the spatial patterns of the diatom assemblages. (3) Path analysis results showed that both LULC types and water quality variables exerted significant effects on diatom assemblages. This study first clarifies the quantitative relationships among LULC types, water quality, and diatom assemblages in the Beijing area. And green land was positively correlated with water quality and river ecosystems. We believed that increasing green space in urban core areas is an effective measure for improving water quality and restoring river ecosystems in the urban area.

Properties of Biofilm Prokaryotic and Eukaryotic Communities in a Representative Hypereutrophic Urban River

ABSTRACT Biofilms play an important role in nutrient and food web dynamics of shallow aquatic ecosystems. Multiple prokaryotic and eukaryotic microorganisms within biofilms interact with each other to shape the community structure and their functional attributes. However, there is no clear understanding of varied patterns of biofilm prokaryotic versus eukaryotic microbial abundances, diversities and communities, which limit our understanding of how biofilm communities and functions in hypereutrophic urban river ecosystems are changing. To elucidate the properties of biofilm communities and controls on biofilm communities in a hypereutrophic urban river, we conducted a one‐year study to investigate the seasonal and water‐depth variations on the abundance/biomass, diversity and structure of biofilm prokaryotic and eukaryotic communities. The structure and dynamics of biofilm prokaryotic and eukaryotic communities were determined by high‐throughput sequencing based on the 16S and 18S rRNA gene. Sequencing revealed that Proteobacteria, Bacteroidota and Cyanobacteria were the three dominant phyla in biofilm prokaryotic communities, and Rotifera, Chlorophyta, Annelida and Bacillariophyta were the four dominant phyla in biofilm eukaryotic communities. Biofilm bacterial abundance depended mainly on the water temperature, whereas biofilm algal biomass correlated with rotifer grazing and light levels. Prokaryotic communities had higher species richness and diversity than eukaryotic communities. Species richness and diversity displayed significant seasonal variations with minima for prokaryotic communities in winter and eukaryotic communities in summer, which were linked to water temperature and rotifer grazing, respectively. Variations in biofilm prokaryotic and eukaryotic community composition were mainly related to ammonia concentration and water temperature, respectively. The co‐occurrence network analysis suggested that rotifer grazing could considerably decrease the complexity of the biofilm network in summer, and the algal groups, especially for Chlorophyta and Bacillariophyta, were the key to the formation of stable biofilm networks. There were significant differences in seasonal and water‐depth heterogeneity of biofilm prokaryotic and eukaryotic community composition. Our findings indicate that variations in water temperature, light level, rotifer grazing and nutrients (especially ammonia) appreciably contribute to changes in the abundance, diversity and composition of biofilm prokaryotic versus eukaryotic communities in the hypereutrophic urban river. These findings increase our understanding of biofilm community characteristics in hypereutrophic urban rivers and provide insights for water pollution remediation strategies.

Did green infrastructure improve water purification ecosystem services in Shandong Peninsula urban agglomeration? Evidence from total phosphorus

Non-point source pollution significantly impacts the sustainable development of river ecosystems. Water purification ecosystem services (WPES) play a crucial role in mitigating non-point source pollution. Green infrastructure (GI) maintains ecosystem services; however, how GI affects WPES remains poorly explored. Using total phosphorus (TP), we investigated the mechanisms by which GI and its structure and functions influence WPES in the Shandong Peninsula urban agglomeration. Results show that GI significantly improved WPES, with the lower TP loads (49-fold) and TP export capacity (3-fold) in GI areas compared to non-GI areas. These effects are associated with specific GI attributes, including structural connectivity, vegetation coverage, and soil conservation capability, which exhibit cascading effects (|r| > 0.8). Optimizing GI structural connectivity can indirectly regulate WPES by enhancing GI ecological functions (vegetation coverage and soil conservation), making it a crucial land management strategy. Specifically, the enhancement of vegetation coverage, which is critical for improving WPES (|r| > 0.6), should focus on both the ‘scale’ and ‘health’ of the vegetation. Cultivating GI (|r| > 0.6) offers greater benefits for WPES than forests and grasslands alone (|r| < 0.6). Effectively leveraging the relationships between GI attributes and WPES can significantly reduce TP risks.

Assessment of Water Poverty Index (WPI) Under Changing Land Use/Land Cover in a Riverine Ecosystem of Central India

Watershed Development is a very common phenomenon in the river basins in India due to its dynamic and continuously changing nature, which are interconnected via. Land use/land cover (LULC) change and water poverty scenario over time. In the present study, the samples were chosen from seven sampled villages for the Water Poverty Index (WPI) in the upper Tons River Basin. Among them, Ghunwara and Maihar Village exhibit the highest and lowest WPI, i.e., 98.1 and 62.91 out of 100, respectively. This indicates that villages with a high WPI face challenges in their water requirements, regardless of the seasonal river serving the basin area. Conversely, villages with a low WPI can satisfy their water needs solely from the basin. The present analysis of the Upper Tons River Basin suggests that Land Use and Land Cover (LULC) will undergo influences or adjustments at various stages, ultimately affecting agricultural land in the impact region. It also becomes evident that areas with limited land use and land cover (LULC) extensions exhibit lower Water Productivity Index (WPI), primarily due to their reliance on agricultural land. It is observed that alterations, reductions, or modifications in LULC lead to changes in multiple aspects of agricultural land, resulting in noticeable variations in various metrics. The present paper not only evaluates the land use in the Upper Tons River Basin spanning from 2001 to 2021 but also highlights the changing patterns that impact water resources and their utilization capacity. Furthermore, the study estimates the influence of reducing specific features on the distribution of WPI and other LULC parameters. The Upper Tons River Basin faces challenges such as unfavorable rainfall patterns and inadequate planning for irrigation at the fundamental and local levels. Additionally, its geographical location in a rainfed area negatively affects the WPI.

Effects of Channelization on Macroinvertebrate Assemblages in a Small Stream: The Case of Awetu in Jimma City, Ethiopia

Freshwater ecosystems are increasingly modified worldwide by anthropogenic activities. Land use change is one of the leading factors responsible for stream ecosystem degradation. Physical habitat disturbance due to channelization is among the factors responsible for the loss of biodiversity and degradation of river water quality worldwide. Since 2020, Jimma City municipality has been beautifying the city and one of the activities is channelizing using concrete embankment, a part of the Awetu stream that runs through the city. The main aim of this study is to assess the effect of channelization on macroinvertebrate assemblages and the water quality of the Awetu stream. A cross-sectional study was conducted in April 2022. Macroinvertebrates, water samples, and habitat data were collected from 21 sampling sites along the three segments of the stream (upstream, channelized, and downstream). Data were analyzed for different macroinvertebrate metrics and water quality parameters. Canonical Correspondence Analysis was used to examine the overall relationship between macroinvertebrate assemblages and water quality parameters. The upstream site has better macroinvertebrate assemblages than channelized and downstream sites (p<0.05). The downstream site showed better assemblage compared to the channelized site, though it was not significant. Regarding water quality parameters, a significant variation was observed between channelized and, un-channelized sites (upstream and downstream) (p<0.05). The habitat condition score varied from 47 (poor) at channelization to 150 (suboptimal) upstream. Upstream sites were found to have relatively better macroinvertebrate assemblages, better water quality, and good habitat conditions. The downstream sites had lower macroinvertebrate assemblages, poor habitat conditions, and degraded water quality compared to the upstream sites. The channelized segment had the poorest habitat, with poor macroinvertebrate assemblages and water quality. Thus, the conservation of habitat conditions along the channelized segments of the Awetu stream is recommended to improve the water quality and macroinvertebrate assemblage.

A Spatial Model of Microplastic Pollution Mitigation as an Effort to Preserve the Brantas River Ecosystem

A Spatial Model of Microplastic Pollution Mitigation as an Effort to Preserve the Brantas River Ecosystem

Multiple biomarker response (Organ Histology, Serum Biochemistry and Oxidative Status) in Catfish Captured from Ureje River, Nigeria

Abstract With rapid urbanisation coupled with the influx of more people to Ado-Ekiti, it is pertinent to assess the effect of human activities on living organisms in Ureje River, the main water body that cuts across Ado-Ekiti. This study examined the effects of environmental pollution on the Ureje River in Ado Ekiti, Nigeria with focus on water quality, heavy metal contamination, and the health of female African catfish. Samples of water were fetched from various fishing spots along the river, and an earthen pond, which served as a control. Blood samples were collected from fish samples farmed from different fishing points, and thereafter slaughtered and organ characteristics and histology assessed. Fish from Emirin and Erinfun showed lower (p&lt;0.05) weights, indicating impaired growth. Fish had significantly (p&lt;0.05) elevated glucose at Ajebamidele, high total protein at Aduloju, Erinfun and Ajebamidele, and varied cholesterol levels, reflecting metabolic stress. Fish from polluted points had notably higher liver enzymes and alkaline phosphatase coupled with highest oxidative stress, indicating liver damage and stress. Fish from heavily polluted areas had necrosis in gills, liver steatosis, and kidney infiltration. Pollution from industrial, agricultural, and domestic sources significantly degrades the Ureje River ecosystem with negatives impacts on water quality and aquatic organism health

Comparison of Eco-Hydrological Limits as Water Scarcity Indicators for the Water Balance Inventory of Slovakia

Abstract Various methods for determining environmental flows can be based on hydrological characteristics, a combination of morphological and hydrological characteristics, or solely on hydraulic characteristics. Such methods may also be based on multi-criteria decision-making, where a low flow regime and its variability are considered. The methods for determining environmental flows as hydrological limits (sometime called desktop methods) are solely based on hydrological statistics and are believed to implicitly incorporate links to the state of river ecosystems. In the paper, we compared the performance of several methods in the set of the 137 official water balance inventory profiles of the Slovak Hydrometeorological Institute, which are evenly distributed over the territory of Slovakia. The analysis also accounted for the dependence between hydrological characteristics and environmental flow values. We also compared the frequency of the occurrence of their critical values (ecohydrological) in the reference periods 1931-1960 and 1991-2019. We proposed an intermediate system of regionalized relationships based on simple Tennant methods, which does not disturb the existing system of water allocations and uses in the water balance inventory.

Assessment of River Ecological Health Status and Interbasin Water Transfer Potential: Case study of Luapula River Basin in Zambia

Water transfer is one mechanism for meeting increasing water demand in water-stressed areas. However, moving water from one area to another often disturbs the ecosystem including the fisheries biodiversity and growth patterns. Thus, when contemplating water transfer, baseline information on the status of the fisheries biodiversity and condition is cardinal for sustainable fisheries management during and after water transfer implementation. This work aimed at investigating the current fisheries condition (biodiversity, weight length relationship and condition factor) of the Luapula River Basin (LRB) to explore potential and implications for future interbasin water transfer on the basin fisheries. The fishes were sampled during the 2022/2023 dry and wet season at selected sites in LRB. Biodiversity indices, fish weight/length relationship and condition factor were used to describe the fish biodiversity, growth patterns and wellbeing which described the status of the aquatic condition of the donor basin. Species Richness, Shannon Diversity Index, Simpson Index and Evenness ranged between 0.8902 to 1.664, 0.9167 to 2.1437, 0.4416 to 0.8683 and 0.4172 to 0.8940 respectively. The growth coefficient (b) ranged from 1.223 to 3.755 indicating negative and positive allometric growth. The condition factor ranged between 0.692 and 2.218. Thus, it can be said that the LRB has good fish biodiversity albeit with some species showing dominance, normal growth pattern and wellbeing showing bias towards undisturbed habitats and physiological state. As such, this status quo of LRB needs to be maintained prior to, during and after IBWT implementation.

Taxonomic composition of phytoplankton in various continental aquatic hydroecosystems of Ukraine

The paper deals with present-day taxonomic composition of phytoplankton in various continental aquatic ecosystems of Ukraine (Kaniv Reservoir, the Western Bug River (with tributaries), Prypiat River (with tributaries), Sula River (within Nyzhniosulskyi National Natural Park, ponds (Hostomel town), large lakes of the Danube River) according to the modern algological nomenclature AlgaeBase. Within 2000–2022 in the phytoplankton of aquatic ecosystems under study 455 species of algae were identified, represented by 467 infraspecies taxa from 206 genera, 102 families, 53 orders, 18 classes and 8 phyla. The most diverse were Bacillariophyta (25–50%), Chlorophyta (22–39%) and Cyanobacteria (7–16% of floristic spectrum). Phytoplankton responds to present climate change by increase in Cyanobacteria share. The taxonomic hierarchy of algae, identified in plankton, is characterized by the following regression: Bacillariophyta &gt; Chlorophyta &gt; Cyanobacteria &gt; Ochrophyta &gt; Euglenozoa. Analysis of the taxonomic composition of Bacillariophyta at different levels of their systematic hierarchy (families, genera — according to Kendall index; species (infraspecie taxa) — according to Sørensen index) has made it possible to reveal the following patterns. The Kendall index for leading families varied within 0.31–0.72. The highest level of similarity was observed for lotic ecosystems. The Kendall index for leading genera varied between 0.11 and 0.59. The highest similarity level was observed between ecosystems of one type, for example, lotic (the Prypiat River and the Western Bug River) or lentic (ponds of Hostomel town and large Danube lakes). Cluster analysis of species similarity according to Sørensen index shows that two clusters can be distinguished in the dendrogram: lotic ecosystems and lentic ecosystems. The long-term data on the taxonomic composition of phytoplankton (algae present in water column at the moment of sampling) give evidence of high diversity thereof in various aquatic ecosystems of Ukraine.