Inland Waters Research Articles

Economic assessment and sustainable management of artisanal fisheries: Insights from River Jhelum, Kashmir, India

This study was conducted to comprehensively assess artisanal fishers’ economic and financial viability, relying heavily on a shared resource, namely the River Jhelum. Employing a proportional multi-stage stratified sampling approach, a total of 200 fishers were interviewed across six districts in Kashmir, covering the entire length of the river. The Benefit Cost Ratio (BCR) of 1.1, coupled with a positive Net Present Value (NPV), underscores the economic profitability of artisanal fisheries. Constraint analysis highlighted that fishermen express substantial concerns regarding the ongoing decline in both catch and the composition (Garret score: 83) of native fish species, particularly Schizothorax, and pollution in the river (Garret score: 73). Considering the perspectives of all stakeholders, it becomes evident that comprehensive sustainability measures are imperative. To achieve this, multiple stakeholders must collaborate and establish a unified administrative body, solely dedicated to the protection of riverine resources. In addition to implementing a two-month fishing ban and modifying the licensing policy, maintaining a detailed record of daily fish catches, including both biological and economic data, at each fishing site is also crucial. Such actions will facilitate the implementation of optimal exploitation levels for this invaluable inland water resource. Keywords: Constraint analysis, Economic performance, Financial feasibility, Net present value, Schizothorax, Sustainability

Inventory of methane and nitrous oxide emissions from freshwater aquaculture in China

Aquaculture is a major emission source of atmospheric methane (CH4) and nitrous oxide (N2O). However, its contribution remains highly uncertain because the source has been neglected in global and national greenhouse gas inventories. Here, we present an inventory of CH4 and N2O fluxes from five freshwater aquaculture systems in China, which accounted for more than half of global freshwater aquaculture production during 2000-2020. We show that total CH4 and N2O emissions were 2.5 (0.6-4.2) Tg CH4 yr-1 and 18.3 (3.8-32.2) Gg N2O yr-1, respectively, with 75% coming from ponds and paddy fields. CH4 and N2O effluxes from freshwater aquaculture were 5 and 2 times higher than the average from other inland water bodies, respectively. Aquaculture accounts for half of the national inland water emissions, and outweighs the land soil methane sink. We suggest that tracking aquacultural emissions and their reduction through aerated systems could provide additional opportunity to reduce agricultural non-CO2 emissions without compromising food security.

Multiscale spatial variability in land and water productivity across the Gezira irrigation scheme, Sudan

Agricultural performance assessment spans various spatial scales, from single plots to entire irrigation systems. A multi-scale analysis is thus crucial for informed decision-making. The Gezira irrigation sScheme in Sudan is a longstanding large-scale irrigation system experiencing severe water management challenges, manifested by low land productivity, water productivity, and irrigation efficiency. Recognizing the interdependence of decision-making, this research focuses on variations in water and land productivity at different spatial scales within the Gezira irrigation scheme. As one of the world’s largest gravity-irrigated systems, covering 2.1 million feddan (1 feddan = 0.42 ha ∼ 1 acre), the scheme serves as an interesting case to study head-tail performance variations across four spatial scales: tertiary, secondary, and major units, and the whole scheme. This study is centered on the winter season wheat cultivation 2022–2023, and employs the FAO’s Water Productivity Open Access Portal (WaPOR v2.1) datasets, with 100 m resolution, for computing land and water productivity. Ground-observed yield data from nine tertiary units (nimras) in the Wadelbur irrigation division were used to validate WaPOR. The results showed a systematic underestimation of WaPOR derived land productivity by about 40 % compared to the ground dataset. The head-tail analysis of land and water productivity reveal contrasting results at different scales. At tertiary and secondary scales, no correlation exists between distance from offtake and productivity. At the major unit (irrigation division), a moderate correlation is observed: 0.7 for land productivity, and 0.6 for water productivity. At the scheme scale, the correlation factors are somewhat lower for land productivity (0.4) and the same for water productivity (0.6). At the largest scale, the productivity appears to increase from head to tail divisions, suggesting potential overirrigation and waterlogging in the head parts leading to reduced productivity. Another possibility is the presence of better agricultural practices in the tail areas compared to the head.

Use of Machine Learning and Indexing Techniques for Identifying Industrial Pollutant Sources: A Case Study of the Lower Kelani River Basin, Sri Lanka

With the recent acceleration in urbanisation and industrialisation, industrial pollution has severely impacted inland water bodies and ecosystem services globally, causing significant restrains to freshwater availability and myriad damages to benthic species. The Kelani River Basin in Sri Lanka, covering only ~3.6% of the land but hosting over a quarter of its population and many industrial zones, is identified as the most polluted watershed in the country. This study used unsupervised learning (UL) and an indexing approach to identify potential industrial pollutant sources along the Kelani River. The UL results were compared with those obtained from a novel Industrial Pollution Index (IPI). Three latent variables related to industrial pollution were identified via Factor Analysis of monthly water quality data from 17 monitoring stations from 2016 to 2020. The developed IPI was validated using a Long Short-Term Memory Artificial Neural Network model (NSE = 0.98, RMSE = 0.81), identifying Cd, Zn, and Fe as the primary parameters influencing river pollution status. The UL method identified five stations with elevated concentrations for the developed latent variables, and the IPI confirmed four of them. Based on the findings from both methods, the industrial zones along the Kelani River have emerged as a likely source of pollution in the river’s water. The results suggest that the proposed method effectively identifies industrial pollution sources, offering a scalable methodology for other river basins to ensure sustainable water resource management.

Mitigating inland waters’ greenhouse gas emissions: current insights and prospects

ABSTRACT Natural and constructed inland waters emit globally significant amounts of greenhouse gasses (GHGs) into the atmosphere. As a result of human-induced alterations in the landscape, these emissions tend to increase. While proper management of waterbodies is fundamental to reaching the global sustainable development goals as well as the Paris Agreement, insights on climate-smart inland water management are still underexplored. Here we review and discuss physical, chemical, and biological management measures applied in a wide range of inland waters to (1) reduce external loads of compounds fueling aquatic GHG emissions, (2) reduce the aquatic production of GHG-fueling compounds, and (3) minimize GHG production and stimulate GHG consumption. Some measures are well studied and others are in the exploration phase, resulting in a varying degree of confidence with respect to their effectiveness. Climate-smart water management (e.g., through the reduction of organic matter and nutrient loading) generally not only reduces GHG production and emission but also improves the ecological state of aquatic environments. Reductions in GHG emissions from 5% (fish effect) to ∼90% (salinization effect) were observed among the climate-smart measures discussed here. Certainly, the global effect of the different measures also depends on the application scale. Depending on the local context, the implementation of one or more of these measures can be considered in a GHG mitigation program.

Emerging research on characterizing the potential of cable bacteria for CH4 mitigation

Methane (CH4) contributes an essential portion for global warming as a pivotal greenhouse gas. Microorganisms are identified as an effective way to mediate and control CH4 emission. Cable bacteria is a promising microorganism to mitigate CH4, however, the studies of distribution, abundance and function for CH4 reduction of cable bacteria in inland water still remain unclear. In this paper, we propose the probable CH4 mitigation metabolism within cable bacteria in anoxic condition, and present the future research directions about the application potential of cable bacteria in CH4 reduction. The viewpoint will help to understand the significant role of cable bacteria in CH4 mitigation and provide a potential way to control CH4 emissions in inland freshwater ecosystem.

Dynamics of urban development patterns on thermal distributions and their implications on water spread areas of Vellore, Tamil Nadu, India

Recent satellite maps have reported that India is experiencing extreme heat waves, surpassing even Middle Eastern countries. This study addresses a critical gap in understanding how land use land cover (LULC) changes impact land surface temperature (LST), urban heat intensity (UHI), and water spread area (WSA) in rapidly growing cities such as Vellore and Katpadi over three decades (1997–2024). We used Landsat thermal bands and the support vector machine (SVM) algorithm to investigate LULC and LST patterns, examining the effects of urbanization and water body reduction on local climate dynamics. The LULC results showed an increase in built-up lands from 5.89 to 25.89%, while zooming water areas shrank from 3.15 to 1.02%. LST showed a significant increasing trend, with temperatures for water bodies and vegetation ranging from 17.4°C to 26°C, and for barren and built-up areas from 28°C to 42.6°C. The results of the multivariate analysis revealed a positive correlation between LST and the Normalized Difference Built-up Index (NDBI) and negative correlations between LST and the Normalized Difference Vegetation Index (NDVI), the Normalized Difference Water Index (NDWI), and the Modified Normalized Difference Water Index (MNDWI). Moreover, spatial and time series analyses of WSAs indicated a significant increase in LST. Furthermore, a strong negative correlation was found between WSA and LST, with a 10% decrease in WSA potentially increasing LST by 0.12°C to 0.55°C in surrounding regions. This study offers important contributions to improving land use policy and water resource management in urban areas, while addressing environmental concerns related to rising temperatures. The findings underscore the urgency of mitigating heat impacts and managing water resources in rapidly expanding cities. Our results provide valuable insights for policymakers and practitioners aiming to develop more sustainable, resilient, and livable urban environments.

Establishing the water resources implications for closing the land and water productivity gaps using remote sensing – A case study of sugarcane

ContextTwo of the key limitations for sustainably increasing agricultural production are the scarcity of land and fresh water resources. Establishing land and water productivity gaps is, therefore, essential for measuring how efficiently these resources are being utilised and assessing the scope for increasing feed and food production. Monitoring the productivity gaps at large scales or over time using field data is challenging and expensive. Remote sensing offers an alternative data source to reveal spatial and temporal variations in productivity. ObjectiveThis paper presents a framework that integrates remote sensing derived data and field data to assess (1) land and water productivity gaps, (2) bright spots – fields exhibiting land- and water productivity equal to or higher than the target, and (3) net irrigation water demand for increasing production. MethodsThe framework is developed and applied to the Xinavane sugarcane estate in Mozambique, demonstrating its practical application through systematic evaluation on a 6637 ha section of the estate divided by different irrigation application methods. ResultsThe results reveal that the productivity gap is the highest on fields irrigated by furrow (13.1 tonnes (ton) per ha), followed by sprinkler (12.6 ton/ha) and centre pivot (9.4 ton/ha). Bridging the productivity gap on the same cropland results in an increased sugarcane production of 12.5 % requiring 8.5 % additional irrigation water, whereas achieving the same production increase through irrigation expansion requires more blue water. ConclusionsThe analyses show that remote sensing provides a viable source of information to diagnose the productivity constraints and how bright spots can provide insights into the best field management practices to overcome them. The framework demonstrates its usefulness for policy makers and stakeholders to make informed decisions on the scarce blue water allocation for enhancing agricultural production.

Land Cover and Water Ecosystem Services: Assessment of Bigbiga Protected Landscape (BPL)

Land Cover and Water Ecosystem Services: Assessment of Bigbiga Protected Landscape (BPL)

Evaluating the characteristics, trends and challenges of marine fisheries in Iraq

The characteristics, trends and challenges of the marine fisheries of Basrah province, Iraq were studied in this study. Information on fish landings was gathered from the main landing site of the marine fisheries at Al-Fao port from January 2023 to December 2023. The total landing of marine fisheries was 29,446 tons for 28 fish species and two shrimp species. Threadfin bream constituted 10.87% of the landing, followed by Mullets (9.72%) and Emperor (9.39%). Shrimp formed about 13.87% of the total catches. The landings of Threadfin bream and Emperor, as well as shrimp, significantly increased in 2023, while the contribution of historically more important species such as the landing of river shad has decreased to the lowest level. Therefore, from a fisheries management perspective, it is crucial to manage the stock of various species, especially River shad by ensuring the right amount of water is obtained from the upper Tigris and Euphrates Rivers to marine waters through the Shatt Al-Arab River, implementing national fishing regulations to deter illegal fishing methods and safeguard the fish during their migration, reproduction, and in their nursery habitats in inland waters.

Integrating climate-smart agriculture for sustainable agriculture: Opportunities, challenges and future directions

Climate-smart agriculture (CSA) has emerged as a valuable strategy to address the challenges of food insecurity, climate change, and environmental degradation. This study assesses the impact of six key CSA practices: technologies including water smart, energy smart, nutrient smart, carbon smart, weather smart, and knowledge smart for farming regarding the increasing world population and decreased shift in arable land. This paper employs a literature review and case analysis to demonstrate how these practices improve resource utilization, worsen environmental impacts and strengthen agriculture production systems. Several studies carried out in agriculture have stipulated that water-smart practices can help achieve improvements in water use efficiency by at least 30 percent, nutrient-smart practices can help increase soil health by a range of 20 percent, and carbon-smart practices could reduce greenhouse gas emissions by between 15 percent. This brings us back to the question of the role that CSA can play in support of processes that are directed at realizing the Sustainable Development Goals SDG 2 (Ending Hunger) and SDG 13 (Taking Action on Climate Change) on development processes across the world. However, inefficient and insecure land rights, water deficits, and high initial investment hinder the widespread adoption of the technologies. The consequences are that policies concerning the matters, a well-developed institutional environment, and farmer’s knowledge should be introduced to eliminate these issues. As to further research, the continuous improvements of the models of CSA and the financing of the CSA also need future action research. Overall, CSA offers hope for establishing strong foundations for food security and climate-resilient agricultural systems.

Navigating the Currents: Land Use Challenges Amidst Water and Food Security Debates and Social Media Misperceptions

This research aims to understand the complexities of energy deployment requiring nexus governance solutions. Nexus governance involves coordinating decision-making across policy areas and sectors, seeking compromise among stakeholders with varying positions. The challenge lies in coordinating diverse sectors and stakeholders amidst potentially conflicting priorities and interests. Moreover, social media significantly influence stakeholders’ perceptions and actions, serving as a platform for idea exchange and mobilization but also contributing to echo chambers and polarization. This study examines the impact of social media on perceptions of the oil shale project in Al Attarat, Jordan, focusing on the intersections of social, economic, and environmental concerns. The findings highlight that social media significantly influences public discourse, often skewing perceptions with misperceptions about land use, water, and food security. Analyzing key social media narratives reveals that food security is a primary concern, with energy and water security also gaining attention, though less prominently. Furthermore, misinformation has exacerbated tensions among stakeholders, leading to polarized views and resistance to proposed governance solutions. This research underscores the need for effective strategies to counter misinformation and promote informed dialogue.

Actual tasks of the development of river container transportation

The article is devoted to proposals within the framework of strategic objectives for the development of multimodality in river cargo transportation. The introduction describes the current state of river port infrastructure, assesses its readiness for containerization and provides statistics on such transportation. The materials and methods formulate strategic objectives for solving the problems of effective functioning of river transport in modern conditions. The results show the technology for reloading container cargo with portal cranes. results of calculating the travel time of container cargo along the route St. Petersburg - Kazan, taking into account transshipment by water and rail transport. The authors included scientific and practical recommendations for the discussion on the formation of a container line and the composition of ports on it. In conclusion, it was concluded that container transportation has prospects for development on river highways, which will contribute to both achieving the strategic goal of developing multimodality in transport and logistics schemes involving inland water transport, and can also lead to an increase in cargo traffic, improving the quality of transport services for clients and increasing competitiveness of river highways, which is especially important in the current conditions of the breakdown of traditional logistics connections.

The innovative vector of technology–based development of shipping companies is autonomous navigation

The article is devoted to the current state of water transport, problems and prospects of its development. Special attention is paid to the innovative vector of development of shipping companies on the basis of technologies - autonomous navigation. The development of the shipping industry on the basis of autonomous navigation opens significant opportunities in the sphere of safety improvement, increase of profit by reducing the costs of maintenance of ship crews. Examples of implementation and use of remote control of a vessel using autonomous navigation means along a socially and economically significant route are given. The article studies the legal acts that came into force in 2024, fixing the legal basis for the creation of autonomous navigation, which gives the opportunity to actively develop this promising direction. It will allow water transport to be competitive, and thus one of the key sectors of the Russian economy to become a pillar for achieving its growth. Based on the study of the materials of the Russian Federation SP in the field of inland water transport development, the factors that will contribute to the efficiency of the implementation of the initiatives of socio-economic development of the Russian Federation until 2030 are proposed.

(Sub‐)Antarctic endemic cyanobacteria from benthic mats are rare and have restricted geographic distributions

The Antarctic terrestrial macrobiota are highly endemic and biogeographically structured, but whether this also holds true for microbial groups remains poorly understood. We studied the biogeographic patterns of Antarctic cyanobacteria from benthic microbial mats sampled in 84 lakes from two sub‐Antarctic islands, as well as from eight Antarctic Conservation Biogeographic Regions (ACBRs) which were previously defined based mainly on macroscopic taxa. Analysis of 16S rRNA gene sequences revealed that Antarctic and sub‐Antarctic lakes host significantly different cyanobacterial communities, yet that the bioregionalization pattern did not correspond to the division into ACBRs. Both Antarctic and sub‐Antarctic lakes contain a high number of potentially endemic taxa (41% of the total diversity), of which 33.3% attain a relative abundance of < 1%. Our findings highlight the uniqueness of Antarctic microbiota and the need for increased protection of inland waters in both Antarctica and the sub‐Antarctic islands.

Multi-tracer evidence of hydrology and primary production controls on dissolved organic matter composition and stability in the semi-arid aquatic continuum

Autochthonous dissolved organic matter (Auto-DOM) produced by a biological carbon pump using dissolved inorganic carbon (DIC) from carbonate weathering plays an important role in carbon cycling within inland waters. However, little is known regarding how environmental conditions impact the composition and fate of organic matter, especially in surface waters of the semi-arid Loess Plateau, which is enriched in DIC by significant carbonate weathering. To obtain novel insight, we combined hydrochemistry, isotopic composition (δ2H, δ18O, and δ13CDIC), Rayleigh fractionation model, optical spectroscopy (absorbance and fluorescence), and Fourier transform ion cyclotron resonance mass spectrometry measurements to elucidate how primary production and hydrology impact the composition of DOM and the stability of the resulting Auto-DOM throughout the river–reservoir–wetland aquatic continuum of the Bahe River in the carbonate-mineral-rich semi-arid Loess Plateau where carbonate weathering is significant. The Rayleigh fractionation model results indicated that watershed DIC is primarily consumed through aquatic primary production rather than CO2 degassing. Further investigation revealed that primary production and evaporation co-occurred in this watershed. With the enrichment of the stable water isotope δ2H, the relative abundances of the allochthonous compounds decreased and the relative abundances of the autochthonous substances increased, suggesting that the terrestrial signal of riverine DOM decreased while autochthonous production increased along the flow pathway. In addition, associations between optical and molecular characteristics among DOM samples from different water bodies revealed that the stability ratio (Fmax(C2/(C2 + C4))) of Auto-DOM to the ratio of carboxylic-rich alicyclic molecules showed a consistent trend, suggesting that phytoplankton-derived and biomineralized C2 compounds are potentially recalcitrant DOM in inland waters. We conclude that hydrology and primary production affect the source, composition, and, potentially, the stability of DOM in DIC-enriched surface waters of the semi-arid Loess Plateau, which may lead to a more humic-like DOM composition in inland water and export this lower bioavailability DOC to the ocean in the long term.

Anuran occupancy varies with stream characteristics and flow across Arizona wilderness areas

Abstract Riparian ecosystems comprise less than 2% of the landscape in the arid western United States, yet they provide habitat and resources to over half of arid‐land wildlife species, including a broad diversity of anurans (frogs and toads). Despite this, relatively few studies describe riparian herpetofaunal communities in the Southwest, and remote wilderness areas are particularly undersurveyed. We employed passive acoustic monitoring to capture anuran advertisement calls in wilderness area tributaries of the Verde River, Arizona, USA. In the spring and summer of 2021 and 2022, 13–29 autonomous recording units (ARUs) were deployed along perennial, intermittent and ephemeral tributary stream reaches. We characterized sites based on the per cent of pool, riffle, run and side channel habitat within 100 m of each ARU and quantified substrate, wetted channel width and canopy cover. To relate anuran occupancy to environmental and hydrological variables, we evaluated acoustic detection data using single‐species, single‐season occupancy models. Four species were detected in this study: canyon treefrog (Hyla arenicolor), red‐spotted toad (Anaxyrus punctatus), Woodhouse's toad (Anaxyrus woodhousii) and non‐native American bullfrog (Lithobates catesbeianus), with canyon treefrog being the most ubiquitous species observed. Vocal activity of canyon treefrog was higher at perennial and intermittent sites compared to ephemeral sites, and the presence of pools was most strongly associated with canyon treefrog occupancy. Persistent, slow‐moving water best predicted the presence of breeding canyon treefrogs. Notably, this study did not detect several species with historical records in the middle Verde River catchment, including Arizona toad (Anaxyrus microscaphus) and northern leopard frog (Lithobates pipiens). Given climate change‐related flow declines and intensifying demands for water in arid lands globally, maintaining stream flows that provide consistent and suitable hydroregimes for anuran breeding and larval development is of increasing importance. Determining habitat use and flow regimes necessary to support anuran populations can aid in prioritization of conservation actions related to water management and predict how changes in water availability may impact stream‐breeding anurans.

Elucidating the Composition and Transformation of Dissolved Organic Matter at the Sediment-Water Interface Using High-Resolution Mass Spectrometry.

The exchange and transformation of dissolved organic matter (DOM) at the sediment-water interface are crucial factors in regulating watershed biogeochemistry, with the molecular composition of DOM serving as a pivotal determinant in elucidating this process. High-resolution mass spectrometry (HRMS) is an effective tool for resolving the composition of DOM. By analyzing the compositional characteristics of DOM at the sediment-water interface under three different salinities at the same latitude region in northern China, the findings indicate certain variations in component characteristics of DOM between low-salinity inland waters and high-salinity seawaters, with the former exhibiting greater molecular diversity and higher molecular weights, whereas the latter displayed a higher saturation and bioavailability. Notably, the presence of more CHOS substances in the low-salinity inland waters underscores the transformation of the DOM influenced by terrestrial inputs and anthropogenic activities. Conversely, the presence of more CHO and CHNO substances in high-salinity seawater underscores the microbial effects. The chemical transformation process from overlying water to pore water to sediments was characterized by methylation, hydrogenation, decarboxylation, and reduction, as determined by calculating the relations between the H/C and O/C ratios of different compound types. These findings indicate that HRMS can yield more refined results in revealing the process of DOM at the sediment-water interface under different environments, which provides a more reliable basis for a deeper understanding of the source-sink mechanism of sediment organic matter.

Current Challenges of Vaccination in Fish Health Management.

Vaccination is an essential method of immunological preventive care required for the health management of all animals, including fish. More particularly, immunization is necessary for in-land aquaculture to manage diseases in fish broodstocks and healthy seed production. According to the latest statistics in 2020, 90.3 million tons of capture fishery production was achieved from the aquaculture sector. Out of the above, 78.8 million tons were from marine water aquaculture sectors, and 11.5 million tons were from inland water aquaculture sectors. About a 4% decline in fish production was achieved in 2020 in comparison to 2018 from inland aquaculture sectors. On the other hand, the digestive protein content, healthy fats, and nutritional values of fish products are comparatively more affordable than in other meat sources. In 2014, about 10% of aquatic cultured animals were lost (costing global annual losses > USD 10 billion) due to infectious diseases. Therefore, vaccination in fish, especially in broodstocks, is one of the essential approaches to stop such losses in the aquaculture sector. Fish vaccines consist of whole-killed pathogens, protein subunits, recombinant proteins, DNA, or live-attenuated vaccines. Challenges persist in the adaption of vaccination in the aquaculture sector, the route of administration, the use of effective adjuvants, and, most importantly, the lack of effective results. The use of autogenous vaccines; vaccination via intramuscular, intraperitoneal, or oral routes; and, most importantly, adding vaccines in feed using top dressing methods or as a constituent in fish feed are now emerging. These methods will lower the risk of using antibiotics in cultured water by reducing environmental contamination.

Technology for the conservation of fishery resources in inland waters

Technology for the conservation of fishery resources in inland waters