Wetland Of International Importance Research Articles

Exposure of wetlands important for nonbreeding waterbirds to sea-level rise in the Mediterranean.

Sea-level rise (SLR) is expected to cause major changes to coastal wetlands, which are among the world's most vulnerable ecosystems and are critical for nonbreeding waterbirds. Because strategies for adaptation to SLR, such as nature-based solutions and designation of protected areas, can locally reduce the negative effects of coastal flooding under SLR on coastal wetlands, it is crucial to prioritize adaptation efforts, especially for wetlands of international importance for biodiversity. We assessed the exposure of coastal wetlands important for nonbreeding waterbirds to projected SLR along the Mediterranean coasts of 8 countries by modeling future coastal flooding under 7 scenarios of SLR by 2100 (from 44- to 161-cm rise) with a static inundation approach. Exposure to coastal flooding under future SLR was assessed for 938 Mediterranean coastal sites (≤30km from the coastline) where 145 species of nonbreeding birds were monitored as part of the International Waterbird Census and for which the monitoring area was delineated by a polygon (64.3% of the coastal sites monitored in the Mediterranean region). Thirty-four percent of sites were threatened by future SLR, even under the most optimistic scenarios. Protected study sites and study sites of international importance for waterbirds were, respectively, 1.5 and 2 times more exposed to SLR than the other sites under the most optimistic scenario. Accordingly, we advocate for the development of a prioritization scheme to be applied to these wetlands for the implementation of strategies for adaptation to SLR to anticipate the effects of coastal flooding. Our study provides major guidance for conservation planning under global change in several countries of the Mediterranean region.

Understanding filamentous cyanobacteria and their adaptive niches in Lake Honghu, a shallow eutrophic lake

Freshwater lakes globally are witnessing an escalation in the frequency and intensity of cyanobacterial harmful blooms. However, underlying factors influencing the succession or coexistence of cyanobacteria, especially filamentous ones, remain poorly understood. Lake Honghu, a Ramsar Wetland of International Importance with degrading aquatic ecological quality, served as a case study to elucidate the intricate relationship between environmental changes and cyanobacterial dynamics. Our analysis revealed a significant increase in the dominance of filamentous cyanobacteria, marked by high spatiotemporal variability in community structure. This dominance of filamentous diazotrophic cyanobacteria is attributed to a decrease in the ratio of dissolved inorganic nitrogen to total phosphorus and their capacity to utilize organic phosphorus in phosphorus-deficient conditions. Species-specific density variations were linked to diverse environmental factors, with total nitrogen or total phosphorus concentration remaining as a crucial factor influencing dominant cyanobacterial density fluctuations. The dominance of low-temperature-tolerant Aphanizomenon and Pseudanabaena was evident in spring and winter, whereas Dolichospermum and Cylindrospermopsis, which prefer higher temperatures, thrived in summer and autumn. Additionally, non-algal turbidity and heterogeneity can potentially alter the competitive outcome among filamentous cyanobacteria or foster coexistence under conditions of elevated temperatures and nutrient limitation. This study predicts that filamentous cyanobacteria may spread and persist in lakes spanning a wide trophic range. Current findings enhance our comprehension of the dynamic responses exhibited by filamentous bloom-forming cyanobacteria in the face of environmental changes within shallow eutrophic lakes and provide valuable insights for lake managers involved in the remediation of degraded shallow lakes.

Artificial Neural Networks for Mapping Coastal Lagoon of Chilika Lake, India, Using Earth Observation Data

This study presents the environmental mapping of the Chilika Lake coastal lagoon, India, using satellite images Landsat 8-9 OLI/TIRS processed using machine learning (ML) methods. The largest brackish water coastal lagoon in Asia, Chilika Lake, is a wetland of international importance included in the Ramsar site due to its rich biodiversity, productivity, and precious habitat for migrating birds and rare species. The vulnerable ecosystems of the Chilika Lagoon are subject to climate effects (monsoon effects) and anthropogenic activities (overexploitation through fishing and pollution by microplastics). Such environmental pressure results in the eutrophication of the lake, coastal erosion, fluctuations in size, and changes in land cover types in the surrounding landscapes. The habitat monitoring of the coastal lagoons is complex and difficult to implement with conventional Geographic Information System (GIS) methods. In particular, landscape variability, patch fragmentation, and landscape dynamics play a crucial role in environmental dynamics along the eastern coasts of the Bay of Bengal, which is strongly affected by the Indian monsoon system, which controls the precipitation pattern and ecosystem structure. To improve methods of environmental monitoring of coastal areas, this study employs the methods of ML and Artificial Neural Networks (ANNs), which present a powerful tool for computer vision, image classification, and analysis of Earth Observation (EO) data. Multispectral satellite data were processed by several ML image classification methods, including Random Forest (RF), Support Vector Machine (SVM), and the ANN-based MultiLayer Perceptron (MLP) Classifier. The results are compared and discussed. The ANN-based approach outperformed the other methods in terms of accuracy and precision of mapping. Ten land cover classes around the Chilika coastal lagoon were identified via spatio-temporal variations in land cover types from 2019 until 2024. This study provides ML-based maps implemented using Geographic Resources Analysis Support System (GRASS) GIS image analysis software and aims to support ML-based mapping approach of environmental processes over the Chilika Lake coastal lagoon, India.

Gaps in gender reporting in National Reports of Convention on Wetlands of International Importance (2021–2022)

Context The Ramsar Convention is the world’s premier environmental treaty for wetlands. This perspective evaluates gender reporting in Ramsar Convention National Reports and compliance with Gender and Wetlands Resolution XIII.18. A total of 71.8% (n = 42) of the sampled nation reports (n = 133) did not submit National Reports. Zero nations provided statistics on equitable pay or pay gaps by gender. In the sampled reports, only 10 nations submitted sex-disaggregated data. Further, only 7.5% (n = 123) of the sampled National Reports (n = 133) provided sex-disaggregated gender data relevant to the Ramsar Convention. Fifteen National Reports deleted the question on gender (Section H) on from their report entirely, including Denmark and Germany. With evidence drawn from the submitted National Reports, this perspective provides concrete empirical suggestions for improving gender reporting in the future. Gender initiatives, including Resolution XIII.18 and the related Sustainable Development Goals (SDGs) have improved transparent gender reporting in the Ramsar Convention National Reports to a degree. However, on the basis of this review, there is room for improvement in national reporting. Methods National Reports from 2021 to 2022 were reviewed for all instances of ‘gender’ and then evaluated for national replies to Section H, focused on gender. Key results Five years after Resolution XIII.18, there is still a need for system-wide improvements in gender reporting, including sex-disaggregated data, and equity for women (cis and trans) for the Ramsar Convention to become compliant with Resolution XIII.18. Complying with Resolution XIII.18 is one concrete, global and measurable way for wetland science and policy to mainstream gender. Conclusions No nation has prepared a comprehensive answer to Section H on gender and wetland policy and science, as defined below; instead, nations have submitted discrete elements. The analysis of each nation’s answers showed essential elements for a comprehensive answer. In the next 5 years of gender reporting, nations have the option to learn from the past and strive to comply with Resolution XIII.18 and provide transparent sex-disaggregated data on National Heads, community stakeholders, site interpreters, site managers and equitable salary data.

Value of long-term isotope monitoring of an index lake for tracking changes in lake water balances across a northern freshwater landscape

Study regionThe Peace-Athabasca Delta, northeastern Alberta, a Ramsar Wetland of International Importance. Study focusTo explore the cause of change in water isotope composition at an ‘index lake’ (δSSL; ‘PAD 18’), a terminal basin where inflow equals evaporation, and the consequences for characterizing lake water balance across a region subject to the same atmospheric conditions. For two decades, water isotope composition at PAD 18 provided a relatively constant, reliable estimate of δSSL, but experienced a pronounced shift in 2020–2021 when average flux-weighted ice-free season relative humidity increased by 4.6% from 66.2% (2015–2019) to 70.8% (2020–2021). Using flux-weighted air temperature and relative humidity data from 2020–2021, an independent calculation of δSSL was determined to be equivalent to the average isotope composition of PAD 18 during 2020–2021. New hydrological insightsResults reveal re-equilibration of the lake water with the atmosphere following the rise of relative humidity readily provides an explanation for the change in isotope composition of PAD 18. We demonstrate the importance of accurate characterization of δSSL, via the index lake method, for isotope-mass balance calculations using evaporation-to-inflow ratios from measurement of water isotope compositions of 61 lakes across the PAD in July 2021. Findings highlight the value of an index lake and appropriate parameterization of isotope-mass balance models for assessment and ongoing monitoring of water balances of nearby lakes, especially amidst future climatic variability.

Editorial Wetlands for human well-being

Editorial Wetlands for human well-being

Water Reserves for the Environment: A Strategic and Temporal Analysis (2012–2022) for the Implementation of Environmental Flows in Mexico

In Mexico, the evaluations of environmental flows are regulated by the Mexican Norm NMX-AA-159-SCFI-2012, and they warrant the establishment of water reserves for the environment. However, the pressure or demand for water use limits the establishment of said reserves because their implementation is generally conditioned to water availability. This research aimed to evaluate the changes through time of the variables that serve as a basis for the implementation strategy by the Mexican government. A geographical information system was built with updated information on water availability, conservation values, and pressures for all basins nationwide. Their desired conservation status was analyzed, and the potential reserves were estimated based on the reference values. The results were examined according to the ranking changes in environmental water reserves enactment feasibility and desired conservation status of Mexican basins, the progress achieved to date, and the potential contribution to the conservation of protected areas and their connectivity if the gaps of reserves were implemented. The outcomes point towards an administrative implementation strategy with positive results despite the growing demand for water use, with a change rate higher than the one for the creation of new protected areas. Currently, basins with low demand and high conservation value have the potential to meet people’s and the environment’s water needs, and contribute to 86% of the goal set by the present administration without affecting water availability. Finally, reserving water in the priority basins would guarantee the legal protection of the flow regime in 48–50% of the hydrographic network (63,760–66,900 km) in a desired conservation status, 43–49% of wetlands of international importance (48,650–49,600 km2) and other protected areas (128,700–136,500 km2) in 85–89% of the global ecoregions represented in Mexico (780,500–852,200 km2).

Organophosphate, Carbamate and Synthetic Pyrethroid Pesticide Residues in Muscle Tissues of Fish from Loktak Lake, a Ramsar Site in Manipur, India

The muscle tissues of Channa punctatus and Anabas testudineus collected from the Loktak Lake (a Ramsar site) and its three major feeder rivers in Manipur, Northeastern India, were analyzed using high-performance liquid chromatography for the presence of residues of three organophosphorus (malathion, dichlorvos and monocrotophos), one carbamate (carbofuran), and two synthetic pyrethroid (deltamethrin and cypermethrin) pesticides. Residues of all the pesticides except monocrotophos were detected in the fish tissues. Among the five pesticides detected, concentrations of dichlorvos exceeded the maximum residue limit (MRL) prescribed by the Codex Alimentarius for animal tissues such as mammalian offal, eggs and poultry meat. The rest of the compounds were within the MRL for eggs and animal tissues. None of the pesticide residues was detected in the two fish species collected from the control or reference site. The present study indicates that pesticide contamination is emerging as a threat to the water quality and aquatic biodiversity of Loktak Lake, which is a “wetland of international importance” (Ramsar Site) located in a global biodiversity hotspot. The findings of this study also calls for more detailed investigations on the presence of pesticide residues in water, sediments, aquatic macrophytes, planktonic and benthic organisms, and different fish species of this wetland ecosystem.

Temporal dynamics of inundation area, hydrochemistry and brine in Bakhtegan Lake, South-Central Iran

Study regionBakhtegan Lake, southern Iran, is a “Wetland of International Importance” (Ramsar Site). Study focusThis study focuses on analyzing the time series of the lake's inundation area, identifying factors contributing to its shrinkage, and studying its hydrochemical characteristics. To map the inundation area, Landsat images from 1972 to 2019 were used and 64 water samples were collected from the lake during 2017–2019 for geochemical modeling. New hydrological insights for the regionThe study reveals that the Bakhtegan Lake has become a seasonal lake with a long-term dry state since 2007. The lake's inundation area shows a significant correlation with the Kor River discharge, and the main reason for the lake's shrinkage is a decrease in river inflow due to over-exploitation in the basin and construction of two new dams since 2007. The lake water and brine below the lake bed have TDS concentrations varying between 70000 and 451000 mg/L and 118000–373000 mg/L, respectively. The Gibbs, Na-normalized ratio end-member diagrams show that the lake water chemistry is mainly controlled by evaporation. The saturation index indicates that brine samples were in an equilibrium state with gypsum, halite, and glauberite. The Spencer diagram and evolutionary pathway model suggest that water samples shifted toward natural sulfate-rich minerals during evaporation. The lake water evolution model predicts precipitation of halite, kieserite, and carnallite minerals during progressive evaporation.

Celerity of Ice Breakup Front in the Regulated Peace River, Canada, and Implications for the Recharge of the Peace–Athabasca Delta

Timely release of flow from upstream hydropower generation facilities on the Peace River can enhance potential ice-jam flooding near the drying Peace–Athabasca Delta (PAD), a Ramsar wetland of international importance and homeland to Indigenous Peoples. An important consideration in deciding whether and when to commence a release is the celerity of the breakup front as it advances along the Peace River. Relevant historical data for a key stretch of the river are analyzed to determine average celerities, which can vary by an order of magnitude from year to year. Seven breakup events are identified that might have been candidates for a release, and the predictability of associated celerities is explored in terms of antecedent hydroclimatic variables, including cumulative winter snowfall, snow water equivalent on 1 April, ice cover thickness, coldness of the winter, and freezeup level. It is shown that celerity can be predicted to within a factor of two or less, with the freezeup level giving the best results. Three of the seven “promising” events culminated in PAD floods and were associated with the three highest celerities. The empirical findings are shown to generally align with physical understanding of breakup driving and resisting factors.

An analysis of policy and legal framework on wetland conservation and management in South Africa

South Africa has a wealth of wetlands that provide a range of environmental, cultural and economic goods and services. In recognition of the importance of wetlands, South Africa has been a member of the Ramsar Convention on Wetlands of International Importance (also referred to as the Ramsar Convention) since 1975. Apart from this international commitment, South Africa has developed an array of environmental laws and policies that serve as instruments for protecting and managing wetlands. The study aimed to analyse the strengths and limitations of South Africa’s environmental policies and legislative framework that promotes wetland protection and management. The Constitution and nine environmental national laws with provisions relating to wetland conservation and management were thus purposefully selected and analysed qualitatively. The study found that there is no stand-alone wetland policy that protects wetlands; rather, several sectoral policies integrate objectives relating to wetland conservation in the country including those that cover agriculture, the environment, biodiversity and water. This multiplicity means there are no unified management objectives for wetlands protection and conservation. The study also found that there is a lack of harmonisation of policies and legislation, inadequate intergovernmental coordination and no integrated monitoring among the government departments involved. The study concludes that this disjointed and incoherent approach to wetlands conservation and management has weakened the effectiveness of the legal framework and this has obstructed their effectiveness in protecting this sensitive ecosystem.

Environmental Consequences of the Explosion of the Kahovsky Hydroelectric Plant on Biodiversity

The purpose of this article is to determine the ecological consequences of the explosion of the Kakhovka hydroelectric plant (southern Ukraine) on the biological diversity of the region. The main research methods were: theoretical generalization and system-functional approach, analysis, synthesis, expedition method. The ecological consequences of the destruction of a hydroelectric dam are divided into two types: drainage and flooding. As a result of the flooding, 48 objects of the nature reserve fund, with a total area of 120 thousand hectares, were affected. Aquatic biotopes and biotopes characteristic of overmoistened areas were the most affected by drainage. 38 rare types of biotopes, which are under the protection of the Bern Convention, were affected by the ecological disaster; wetlands of international importance (so-called Ramsar) with an area of 33,000 hectares in the Dnipro delta and seven objects of the Emerald network. Prospects for further research are related to the study of biotope restoration after an ecological disaster.

Unveiling bacterial consortium for xenobiotic biodegradation from Pichavaram mangrove forest soil: a metagenomic approach.

Pichavaram mangrove forest was established as a wetland of International Importance by Article 2.1 in April 2022 by the Ministry of Environment, Forest and Climate Change, India. Even though it is a conserved site, xenobiotic agrochemical leaching on the forest land during monsoon is inevitable. These threaten the microbial diversity in the environment. Xenobiotic degradation is achieved using bacterial consortia already acclimatised to this environment. This study aims to identify the indigenous microbial consortia able to degrade xenobiotic compounds such as fluorobenzoate, furfural, and steroids. Pichavaram mangrove metagenomic dataset was obtained by shotgun sequencing of soil DNA and processed using the automated tool SqueezeMeta. Further, the DIAMOND database provided the taxonomical classification of the microbes in each contig. With reference to the KEGG database, the selected xenobiotic degradation pathways were confirmed in the dataset. Of 1,253,029 total contigs, 1332, 72 and 1262 were involved in fluorobenzoate, furfural and steroid degradation, respectively. This study identified that microbial consortia comprising Marinobacter, Methyloceanibacter and Vibrio natriegens/Gramella sp. can degrade fluorobenzoate. While Afipia, Nitrosopumilus sp., and Phototrophicus methaneseepsis favour the degradation of furfural compound. The steroid degradation pathway possessed a plethora of bacteria belonging to the phylum Proteobacteria.

The Effect of Papyrus Wetlands on Flow Regulation in a Tropical River Catchment

Africa has the largest area of wetlands of international importance, and papyrus constitutes the most dominant species for many of these wetlands. This hydrological modelling study assesses and quantifies the impacts of these papyrus wetlands on historical baseflow and quickflow, as well as future flood and low flows in the Mpologoma catchment in Uganda. Assessment over the historic period shows that wetlands strongly attenuate quickflow while moderately enhancing baseflow. They play a moderating role in most months, except for the first dry season (June and July), due to the reversal of flows between wetlands and rivers that often occur during this period. Annual estimates show that wetlands are four times better at regulating quickflow than baseflow. Examination of changes at 2 and 4 °C global warming levels (GWLs) indicate that wetlands will play critical roles in mitigating flood risks, with a lesser role in supporting low flows. Wetlands are predicted to lower future mean flood magnitude by 5.2 and 7.8% at GWL2 and GWL4, respectively, as well as halving the average number of flood events in a year, irrespective of the warming level. This work shows that papyrus-dominated wetlands strongly influence catchment hydrology, with significant roles on quickflow, including floods, and highlights the need for their conservation and protection.

Quality of Environmental Impact Assessment Reports for Lodge Developments in Protected Areas: The Okavango Delta Case, Botswana

This paper evaluates the quality of environmental impact assessment (EIA) reports for lodge developments in Botswana’s Okavango Delta, which is a wetland of international importance and forms part of a transboundary conservation area and world heritage site. A quality review of 31 EIA reports, approved between 2013 and 2021, was conducted by applying a context specific EIA report quality review package. The review package consists of four review areas with seventeen categories and 64 sub-categories, adapted from similar international packages to address the specific legal requirements for EIA in Botswana as well as best practice. Results show that the overall quality of the reports are poor, with 71% graded as ‘unsatisfactory’. In general, descriptive areas of the EIA reports fared better, while the performance of the more analytical areas was ‘poor’. Key areas of weakness include - the identification of impacts; prediction and assessment of impact magnitude; as well as identifying alternatives and mitigation measures. Overall results suggest that currently EIA report content is insufficient to inform decision-making towards sustainable tourism development in the Okavango Delta. It is recommended that areas of weakness can be addressed by providing clear strategic direction; developing a central data management system; setting norms and standards for tourism development as well as building capacity and awareness of key stakeholders. This will ensure that EIA remains a tool of choice for decision making and avoid becoming a mere ‘red-tape’/administrative process aimed at securing development approvals.

Impact of climate change factor on the resource (providing) ecosystem services of the Lower Danube wetlands

Problem Statement. Wetlands perform many vital functions, in particular: accumulation and storage of surface waters; protection from storms and floods; strengthening the coastline and curbing water erosion; hydraulic connection with groundwater; surface water purification; nutrient content; deposit formation; pollutants retention; stabilization of local climatic conditions, especially the amount of precipitation and temperature of the near-surface layer of the atmosphere. They are the world's most productive ecosystems, focus of biodiversity, sources of water and primary productivity on which the existence of innumerable species of plants and animals depends. Wetlands support numerous species of birds, mammals, reptiles, amphibians, fish and invertebrates. The ecological character of wetlands is the totality of their ecosystem components, processes and services at one time or another. Wetland ecosystem services are understood as the benefits that people receive from these. These are providing services (water and food); regulatory services (regulation of floods, droughts, land degradation, etc.); supporting services (soil formation, nutrient cycling, photosynthesis, biodiversity); cultural services (cultural and entertainment, spiritual, religious and other intangible benefits). In Ukraine, there are 2417 wetlands with a total area of about 255 million hectares. Among them are 50 wetlands of international importance with a total area of about 734 thousand hectares, a significant proportion of which falls on the territory of the North-Western Black Sea region coastal zone. The aim of this study is to determine the state, vulnerabilities and climate change impact on the ecosystem services of the «Chilia Branch» wetlands. Research Methodology. To determine the periods of drought, the study used the Standardised Precipitation Evapotranspiration Index (SPEI) from April to October 1980-2023. The SPEI index was calculated at a point located in the southern part of the Danube Biosphere Reserve. The assessment of the state of the vegetation cover was carried out on the basis of the analysis of Normalized Difference Vegetation Index (NDVI) the period 2017-2023 at two sites (Ermakov Island and Limba Island). To analyze dynamics land cover in the wetland area, were used Sentinel-2 land use satellite imagery for the period 2017-2021. Results. Analysis of the SPEI index showed that during the study period there was a positive statistically significant linear trend towards an increase in dry conditions (0.26 / 10 years). In the period 1980-2023 during the growing season on the territory of the "Chilia Branch" wetland, there is a change in weather conditions towards arid, which poses a certain threat. At the same time, it should be noted that the unique hydrological complex of the Danube Delta has a mitigating effect of the atmospheric drought impact on the vegetation. Also, it should be noted that the threat to coastal wetlands is the anthropogenic transformation of coastal natural systems (urbanization processes, expansion of land for agricultural needs, pollution of soil and surface waters), which can lead to loss of habitats of living organisms and deterioration of ecosystem services.

Corrigendum: Identifying the wetlands of international importance in Beibu Gulf along the East Asian – Australasian Flyway, based on multiple citizen science datasets

Corrigendum: Identifying the wetlands of international importance in Beibu Gulf along the East Asian – Australasian Flyway, based on multiple citizen science datasets

Effects of regulation on open‐water flows in the lower Peace River, Canada, and implications for the recharge of Peace‐Athabasca Delta basins

AbstractDownstream impacts of large hydropower dams are often neglected or underestimated, especially for areas situated at long distances from a dam. Naturalization of the flow hydrograph is an important step in assessing hydro‐ecological and socio‐economic impacts of regulation. Using reservoir inflows, a recently developed, lagged‐flow naturalization method is applied to the lower portion of the regulated Peace River, which forms the northern boundary of the Peace‐Athabasca Delta (PAD). The PAD is a Ramsar wetland of international importance that depends on overland flooding for recharge of its high‐elevation or “perched” basins. Such flooding can be caused by ice jams during the spring breakup of the ice cover or by exceptionally high runoff during open‐water flow conditions. Herein, the focus is on the latter type of event and the resulting recharge of basins located within the Peace sector of the PAD. For the period 1972–2017, regulation has reduced open‐water flow peaks by ~4100 m3/s on average, while limiting the possibility of overbank flooding from the Peace River during the summer. Consistent with earlier findings on spring breakup flows, naturalized open‐water peaks do not exhibit a temporal trend. Recharge of non‐perched basins can also occur with moderately high flows that cause no overland flooding but generate flow reversals in Peace River tributaries. In turn, this mechanism can deliver river water to various basins either directly or via connecting channels. Our results show that flow‐based variables that index the hydrological sustenance of non‐perched basins have been significantly reduced by regulation.

Assessment of Heavy Metals Contamination and Potential Ecological Risk in Surface Sediments of the El Bey Wadi, Tunisia

ABSTRACT Sebkhat Soliman included in the Ramsar Convention is a wetland of international importance. This area is of great ecological interest considering the quality and the richness of the flora and the diversity of the avifauna. This site receives a large amount of water through the EL Bey River. In order to assess the levels of contamination, concentrations of six heavy metals, including Cr, Cu, Pb, Ni, Mn, and Zn, were examined in 25 surface sediment samples from El Bey Wadi. These concentrations, which were expressed in mg/kg of dry weight, showed that Pb ranged from 5.52 to 41.66, Zn from 26.94 to 1471.89, Cu from 91.97 to 260.05, Ni from 9.35 to 140.45, Cr from 25. It’s important to note that the highest metal concentrations have been found in site 5 which is frequently exposed to local industrial pollutant sources and in sites that are frequently inundated by river water that is carrying away industrial waste from the cities of Grombalia and Bou-Argoub. The mean EF values for Cu, Mn and Ni were between 3 and 5 in the sediments of the El Bey River, suggesting moderate enrichment, while the mean EF values for Pb, Zn and Cr indicating respectively moderate to severe enrichment and very severe enrichment. CF values for Cr, Cu and Zn were > 6 in sediments taken from the fifth site, which denotes a very high contamination by these metals. At site 5, PLI value (4.09), reflecting that its sediment is heavily polluted. Hierarchical cluster analysis-based complementary statistical methods have demonstrated that Mn is lithogenic and other analyzed metals are anthropogenic.

Local Conservation of Nature Heritage as an Important Component in the Water-Energy-Food Nexus Approach. A Case Study of Srebarna Lake, Bulgaria

Conservation and sustainable use of natural resources are gaining more and more weight on the world political agenda and are attracting the attention of national governments at the highest level. The Water-Energy-Food (WEF) approach helps to understand the interrelationship between natural resources and human activities such as planning, managing, or consuming water, energy, or agricultural products. The world is currently facing the challenge of providing water, energy, and food for all. Scarce natural resources and the environment are increasingly being exploited, while at the same time the demand for fresh water, agricultural products, and energy increases. In this context, the protection of the quality of the available water resources becomes even more important. The preservation of the quality status of water resources is compromised by excessive exploitation, the introduction of polluting substances of different origins, hydromorphological changes in aquatic habitats, and climate changes. The main aim of this article is to clarify the Water-Energy-Food relationship and determine the current physico-chemical state of Lake Srebarna, which is a protected natural site in Bulgaria, a wetland of international importance, a biosphere reserve, and part of the list of world cultural heritage monuments and natural sights of UNESCO.