Urban Wetland Research Articles

Spatiotemporal Variations in Urban Wetlands in Kazakhstan: A Case of the Taldykol Lake System in Astana City

Acquiring a comprehensive understanding of the spatiotemporal dynamics of urban wetlands in Kazakhstan is crucial for their effective preservation and sustainable urban development. Our findings identify past and present Land Use Land Cover (LULC) in the capital city, providing policymakers with scientific evidence for improved management. Using remote sensing and Geographic Information System (GIS) techniques, this study examines the spatiotemporal changes in the Taldykol catchment area during the rapid development of Astana. In 1992, over 90% of the catchment area was grassland and vegetation. By 2022, 30% of the area became barren land. Urban areas increased by 127%, and water areas decreased by 24%. The most significant changes occurred in lakes Taldykol and Kishi Taldykol, whose areas shrank by 91% and 54%, respectively. The near-disappearance of the Taldykol wetlands is likely to contribute to rising land surface temperatures (LST), decreased natural flood control capacity, reduced biodiversity, and diminished recreational opportunities. The fate of Taldykol lakes underscores the urgent need to raise public awareness about the role of wetlands in Kazakhstan’s ecosystems and take action to preserve urban wetlands.

Aquatic Condition Index: optimization of a rapid wetland assessment tool for evaluating urban wetland health

Urbanization poses significant threats to wetland ecosystems, leading to habitat loss, hydrological alterations, and the introduction of invasive species that adversely affect essential ecosystem services. This widespread threat underscores the need to develop a robust management tool for gauging urban wetland health. The Aquatic Condition Index (ACI) was developed as a diagnostic tool for monitoring urban wetland health in Calgary, Alberta, Canada. The ACI evaluates wetland health by incorporating functional indicators (i.e., hydrological, ecological, and water quality functions) chosen by scientific experts to provide municipal wetlands with relative condition scores that can inform citywide habitat management budgeting and prioritization. Gathering the data necessary to generate wetland indicators for the ACI requires substantial financial resources, time, and a high degree of analytical expertise for data collection (e.g., field surveys). This investigation aimed to enhance the widespread applicability and cost-efficiency of wetland monitoring by optimizing the ACI. This optimization entailed a sensitivity-driven indicator reduction, which strategically minimizes the number of indicators essential for ACI calculations. Our findings demonstrate that the refined selection of indicators produces comparable results to the original ACI. This highlights the potential of transitioning to more rapid and cost-efficient monitoring methods, creating a streamlined approach to enhance the efficiency of monitoring and assessment processes. Ultimately, this approach can facilitate long-term urban wetland assessments and promote the sustainability and management of these vital urban features .

Assessment of Ecosystem Service Values of Urban Wetland: Taking East Lake Scenic Area in Wuhan as an Example

Urban wetlands represent a significant ecosystem type within urban landscapes. The quantitative assessment of their ecological service value holds great significance in guiding and improving the urban habitat. However, due to the insufficient spatial resolution of traditional low-to-medium resolution remote sensing imagery for surface monitoring, previous studies have conducted relatively limited research on the ecosystem services of urban wetlands. In this paper, based on multi-source data including multi-scale remote sensing data, a spatial-temporal fusion model and multiple ecological parameter inversion models were employed to invert three key ecological parameters at high spatial resolution, thereby assessing the ecosystem service values (ESVs) of urban wetlands. Taking the East Lake Scenic Area (ELSA) in Wuhan as an example, the dynamics of its ecosystem services’ value components were comparatively analyzed. The results indicate that, while the total value of ecosystem services declined slightly in 2015 compared to 2011, there was a notable increase in their value to CNY 3.219 billion by 2019, which represents a doubling of the total value relative to 2011. This trend could be primarily attributed to a significant rise in cultural services within the region. Specifically, the value of tourism services reached CNY 2.090 billion in 2019, representing a threefold increase compared to 2011. This demonstrates that ecosystem services in the ELSA have been significantly optimized and enhanced through associated ecological projects. Further research should investigate the mechanisms by which urbanization affects these crucial ecosystem services, particularly the characterization of cultural services in urban wetlands, and develop more effective strategies to enhance urban resilience and sustainable development.

Health Risk Assessment of Heavy Metal(loid)s in the Overlying Water of Small Wetlands Based on Monte Carlo Simulation.

Heavy metal(loid) (HM) contamination is a significant threat to wetland ecosystem. However, contamination risks of HMs in overlying water of small wetlands, which are easily ignored because of their minor occupancy in an overall area, are nearly unknown. A total of 36 water samples containing six HMs were collected from the urban and rural small wetlands of Urumqi in China, and the contamination levels and probabilistic health risks caused by HMs were assessed using the Nemerow pollution index (NPI) and the health risk assessment model introduced by the US EPA. The results revealed that the average concentration of Hg in the urban and rural small wetlands surpassed the Class II thresholds of the Environmental Quality Standards for Surface Water (GB 3838-2002) by factors of 3.2 and 5.0 times, respectively. The overall contamination levels of HMs in the small wetlands fall into the high contamination level. Results of a health risk assessment indicated that non-carcinogenic health risk of the investigated HMs are found to be lower than the acceptable range for adults, but higher than the acceptable range for children. Meanwhile, As falls into the low carcinogenic risk level, whereas Cd falls into the very low carcinogenic risk level. Overall, HMs in rural small wetlands showed relatively higher contamination levels and probabilistic health risks than that of urban small wetlands. In addition, As was identified as the dominant health risk factor in the overlying water of small wetlands in the study area. Findings of this study provide scientific support needed for the prevention of HM contamination of small wetlands in arid zones.

How much rainwater contributes to a spring discharge in the Guarani Aquifer System: insights from stable isotopes and a mass balance model

ABSTRACT Outcrops play an important role in groundwater recharge. Understanding groundwater origins, dynamics and its correlation with different water sources is essential for effective water resources management and planning in terms of quantity and quality. In the case of the Guarani Aquifer System (GAS) outcrop areas are particularly vulnerable to groundwater pollution due to direct recharge processes. This study focuses on the Alto Jacaré-Pepira sub-basin, a watershed near Brotas, a city in the central region of the state of São Paulo, Brazil, where groundwater is vital for supporting tourism, agriculture, urban water supply, creeks, river and wetlands. The area has a humid tropical climate with periods of both intense rainfall and drought, and the rivers remain perennial throughout the year. Therefore, the aim of this study is to investigate the interconnections between a spring and its potential sources of contribution, namely rain and groundwater, in order to elucidate the relationships between the different water sources. To achieve this, on-site monitoring of groundwater depth, rainfall amount, and stable isotope ratios (deuterium (2H) and oxygen-18 (18O)) from rain, spring discharge, and a monitoring well was carried out from 2013 to 2021. The results indicate that the mean and standard deviations for δ18O in rainwater exhibit higher variability, resulting in −4.49 ± 3.18 ‰ VSMOW, while δ18O values from the well show minor variations, similar to those of the spring, recording −7.25 ± 0.32 ‰ and −6.94 ± 0.28 ‰ VSMOW, respectively. The mixing model’s outcomes reveal seasonal variations in water sources contribution and indicate that groundwater accounts for approximately 80 % of spring discharge throughout the year. Incorporating stable isotopes into hydrological monitoring provides valuable data for complementing watershed analysis. The values obtained support the significance of the aquifer as a primary source, thereby offering critical insights into stream dynamics of the region.

Investigating the extent that different recreational users of urban wetlands value birds and bird habitat

This study focused on visitors undertaking recreational activities at two important wetland conservation reserves with two main aims: to understand if visitors recognize the significant role of wetlands as vital bird habitat, and to understand the importance of birds as part of the visitor experience. We surveyed 511 visitors at two internationally significant urban wetlands in Perth, Western Australia. Results indicated that respondents valued wetland areas for exercising, aesthetic values, utility of infrastructure and general amenity, as well as the presence of birds. Some respondents perceived that the wetlands were important for birds and the presence of birds was generally rated highly. Results further indicated that while birds were generally not the focus of visitor experience, birds were an important component of that experience. We conclude that most visitors will generally support management actions aimed at conserving the wetlands and birdlife, and management actions do not need to consider a range of differing views across different recreational activities. Thus, understanding the extent that different recreational users of urban wetlands value birds and bird habitat provides vital insights into management approaches for conservation.

Exposure to PFAS contaminated urban wetland water causes similar metabolic alterations to laboratory-based exposures in the freshwater amphipod Austrochiltonia subtenuis

Assessing the harm caused by pollutants in urban ecosystems remains a significant challenge. Traditional ecotoxicological endpoints are often not sensitive enough to detect the effects of toxicants at environmentally relevant concentrations (≤ng/L). A potential solution is using molecular biology methods to look at small biochemical changes caused by exposure to ng/L concentrations of contaminants. This has been tested in the lab but not conclusively demonstrated in the field. We exposed the freshwater amphipod (Austrochiltonia subtenuis) to water from an urban wetland containing known concentrations of per-and polyfluoroalkyl substances (as well as very low concentrations of pesticides) for 14 days and analyzed their metabolite profiles. Mannose, Myo-inositol, and Isopropyl propionate were found to change in PFAS exposed amphipods, a similar response to that previously observed in laboratory exposures to the same PFAS, but not pesticides. The results give a better understanding of PFAS toxicity at environmentally relevant concentrations and conditions.

Evaluation of the Lateral Connectivity of the Suncheon’s Dong Stream Based on Riverside Data

The lateral connectivity of Suncheon’s Dong stream was evaluated based on landside, waterside, and levee data of the river. A total of six items was evaluated, crosssectional structure, vegetation cover ratio, connecting waterway gate, levee slopes, urbanized area ratio and wetland area ratio. Among the items, the connectivity was high in the following order: cross-sectional structure, urbanization area ratio, and levee slope. In a total of 16 survey areas of Suncheon’s Dong stream, one, 12, and three areas were evaluated as continuity, damaged, and discontinuity respectively. The downstream section was evaluated as one continuity and three damaged, the lower-middle stream section was evaluated as one damaged and three discontinuity, and the upper-middle stream and upstream sections were evaluated as eight damaged. The cross-sectional structure, vegetation cover ratio, levee slope, and urbanized area ratio had low lateral connectivity in the lower-middle stream survey section, while the wetland area ratio had high lateral connectivity in the downstream survey section. The lateral connectivity evaluation results of the river aquatic ecosystem in Suncheon’s Dong stream can be used as basic data that is helpful in future ecological river management policies.

Residents’ Awareness and Attitude Towards Urban Wetlands in Accra, Ghana: Implications for Sustainable Urban Development

Residents’ Awareness and Attitude Towards Urban Wetlands in Accra, Ghana: Implications for Sustainable Urban Development

Nesting ecology and confirmed breeding of the invasive pond slider Trachemys scripta in an urban environment, Romania

The pond slider (Trachemys scripta) is a major invasive species in freshwater habitats across the world. For decades, the main cause of individuals’ occurrences in the wild was the illegal release of pet animals. Recently, as an important component of their management, there has been an increasing focus on their ability to successfully reproduce in the invaded regions. In Romania, the species is reported as widespread in urban wetland environments within major cities, but information about its nesting and potential breeding remains scarce or anecdotal. We surveyed a large population of pond sliders in an artificial urban wetland site in Constanţa, SE Romania, and described their nesting ecology and reproductive output. Although eggs from several nests failed to hatch or were predated, potentially limiting their reproductive success, sliders were found to breed successfully at this site, with 18.6% viable hatchlings recorded. Our study could serve as a baseline for additional targeted surveys and to inform decision-making for successfully managing this invasive species. Although the importation, trading, and breeding of this species are prohibited by EU legislation, active and effective management is now required to address the successful reproduction and further potential spread of T. scripta.

Wetland gentrification: the African variant on ecological gentrification

There is growing scholarly interest in notions of ecological gentrification – whereby environmental improvements drive up real estate prices, with the subsequent displacement of low-income residents – particularly in the global North. Drawing on an integrative review of extant literature on African urbanism, urban greenery encroachment and gentrification, this paper argues that the Western notion of ecological gentrification has little or no application in African cities, which are confronted with rapid encroachment on urban wetlands amidst burgeoning urbanization and its attendant increasing demand for property development. We conceptualize the African variant on ecological gentrification as “wetland gentrification”. It occurs when land scarcity and rising property values in African cities cause indiscriminate depletion of urban wetlands for property development, leading to the destruction of ecological resources and displacement of human populations. This paper discusses, among other topics, the implications of wetland gentrification for urban governance and vice versa.

Epiphytic zooplankton community profiles in a typical urban wetland as revealed by DNA metabarcoding

Epiphytic zooplankton community profiles in a typical urban wetland as revealed by DNA metabarcoding

Detection of clade 2.3.4.4b highly pathogenic H5N1 influenza virus in New York City.

Highly pathogenic avian influenza viruses of the H5N1 clade 2.3.4.4b were detected in North America in the winter of 2021/2022. These viruses have spread across the Americas, causing morbidity and mortality in both wild and domestic birds as well as some mammalian species, including cattle. Many surveillance programs for wildlife as well as commercial poultry operations have detected these viruses. In this study, we conducted surveillance of avian species in the urban environment in New York City. We detected highly pathogenic H5N1 viruses in six samples from four different bird species and performed whole-genome sequencing. Sequencing analysis showed the presence of multiple different genotypes. Our work highlights that the interface between animals and humans that may give rise to zoonotic infections or even pandemics is not limited to rural environments and commercial poultry operations but extends into the heart of our urban centers.IMPORTANCEWhile surveillance programs for avian influenza viruses are often focused on migratory routes and their associated stop-over locations or commercial poultry operations, many bird species-including migratory birds-frequent or live in urban green spaces and wetlands. This brings them into contact with a highly dense population of humans and pets, providing an extensive urban animal-human interface in which the general public may have little awareness of circulating infectious diseases. This study focuses on virus surveillance of this interface, combined with culturally responsive science education and community outreach.

Effects of tourism development on ecological network and function of sediment microbial communities in the urban wetland park

Effects of tourism development on ecological network and function of sediment microbial communities in the urban wetland park

Spatio-temporal dynamics of agricultural and built-up areas in the Niaye area of Pikine urban wetland (Dakar, Senegal)

The Niaye area of Pikine, a wetland with favorable physical and climatic conditions, is a rich and varied ecosystem that guarantees a supply of water and fertile soil, conducive to market gardening. This plays an important socio-economic role in the Dakar region. However, this sensitive and fragile ecosystem is often affected by poor farming practices. The aim of the study was to analyze the spatial evolution of agricultural areas and built-up areas in order to identify related environmental problems. Interview guides, aerial photographs from 1966 and 1978 and Digital Globe Over view 2 satellite images from 2004 and 2022 were used. The interview guides were used to obtain data on the management of the market gardening activity, and also to identify the environmental problems it generates. Satellite data processing revealed, through cartographic analysis, a progressive market gardening dynamic of +5.07%. In addition, the built-up area around the lake has increased by over 200%, resulting in a 68.4% decline in upland vegetation and a migration of market gardeners to the lake. This situation leads to the destruction of market garden crops in the rainy season as the water rises. What's more, the intensification of market gardening in response to the population's growing demand for vegetables has not failed to encourage bad practices, including the use of pesticides and sewage, which is a public health problem and a threat to the future of this wetland.

Process of mercury accumulation in urban strip river artificial wetland ecosystems: a case study of Changchun, a typical industrial city in Northeast China.

Mercury (Hg), as a global pollutant, is persistent, migratory, insidious, highly biotoxic and highly enriched, and is widely distributed in the atmosphere, hydrosphere, biosphere and lithosphere. Wetland ecosystems, as active mercury reservoirs, have become the most important sources and sinks of heavy metal mercury. Distinguished from natural wetlands, artificial wetlands located in urban sections of rivers face problems such as diverse urban pollution sources and complex spatial and temporal changes. Therefore, in this study, five intermittently distributed artificial wetlands were selected from the upstream to the downstream of the Changchun section of the Yitong River, a tributary of the Songhua River basin in the old industrial base of Northeast China. The mercury levels in the water bodies, sediments and plants of the artificial wetlands were collected and tested in four quarters from April 2023 to analyse the spatial and temporal distribution characteristics of total mercury. The results showed that the mercury levels in the water bodies, sediments and plants of the five wetlands showed a fluctuating trend with the river flow direction and had certain spatial and temporal distribution characteristics. This phenomenon was attributed to the sinking of external mercury pollution sources. In general, the wetland ecosystems showed a decreasing trend in the total Hg output of the downstream watershed. This may be due to the retention of particulate matter by aquatic plants in artificial wetlands to regular salvage of dead aquatic plants. At the same time urbanization and industrialization affect mercury levels in aquatic environments, so the risk of residential exposure needs to be looked at.

Estimating Combined Effects of Climate Change and Land Cover Change on Water Regulation Services of Urban Wetlands in Valdivia, Chile

AbstractThe relationship between cities and wetland cover varies across the globe, with some cities converting wetlands to low‐ and high‐density urban cover and others preserving, conserving, or restoring wetlands, or constructing new ones. However, the scientific literature lacks studies relating changes in systemic flood risk in an urban stormwater management systems to changes in wetland cover. Furthermore, whether and how such relationships are affected by changing storm intensity under climate change is unknown. We present a case study on the effects of changes in urban wetland extent and storm intensity on flooding in an urban drainage system in Valdivia, Chile, under several co‐produced future scenarios and historical trends of development. We used data derived from stakeholder workshops and historical landcover to determine four plausible scenarios of urban development, plus one business‐as‐usual scenario, in Valdivia through the year 2080. Additionally, we used historical precipitation data and downscaled climate data to estimate event rainfall from extreme storms in the year 2080. We found that system flood volume and time the system was flooded increased with increasing wetland loss and rainfall volume. Mean rate and hour of peak discharge were unaffected by wetland loss. Infiltration's relative role in reducing flooding diminished as wetland loss increased. Cities may still experience dangerous and/or unacceptable flooding even with extensive wetland coverage and will likely need to pair conservation with additional improvements in their stormwater management systems and contributing watersheds.

Diversity and Population Sizes of Wintering Waterbirds in the Wetlands of the Saïss-Middle Atlas Region (North-Central Morocco): Main Survival Factors and Evaluation of Habitat Loss.

Moroccan wetlands host up to half a million wintering birds and provide a stopover for tens of thousands of migrants, while they are inhabited by few nesting species. Most of this avifauna prefers to use the large coastal wetlands or reservoirs, while many species are dispersed across hundreds of small inland wetlands of various types. In this study, we monitored the wintering avifauna of 11 wetlands of the Saïss plain and its adjacent Atlas Mountains (north-center of Morocco), during six wintering seasons (2017-2018 to 2022-2023), with the objective of assessing the importance of this region as a waterbird wintering area. Using the richness of the species, we determine the bird population changes during this pentad and between the different types of wetlands (natural, human-made, and natural wetlands). During this study, we recorded 51 species, belonging to 17 families, among which exist four remarkable birds: the endangered Oxyura leucocephala, the vulnerable Aythya ferina and the near-threatened Aythya nyroca and Limosa limosa. Bird diversity is higher in human-made ecosystems than in peri-urban and natural ecosystems, while the populations' size is similar in urban and non-urban wetlands. With regard to bird conservation, these inland wetlands, mainly the small ones, are threatened by recurrent droughts and various anthropic stressors, which we describe using our observations of the two last decades (2003-2023). The loss of habitat is significant, reaching 348.5 hectares, while the impacts of reduced precipitation and temperature increase are particularly evident in the mountainous natural lakes.

Cyanobacterial bloom affects structural and functional succession of microbial communities in urban wetland sediments in the Qinghai Plateau

Abstract Algal blooms significantly affect microbial communities in wetland ecosystems. However, little is known about the succession of sediment microbial communities during algal blooms. This study aimed to investigate the temporal patterns of sediment bacterial community structure and function succession during algal blooms (March to May 2022) with high-throughput sequencing technology. To this end, algal blooms were divided into the bloom stage (BS), decomposition stage (DS) and end stage (ES). The results showed that: (i) The algal blooms were dominated by Microcystis species within Cyanobacteria. Both phytoplankton abundance and biomass reached the peak in the BS, with 45.78 × 105 cells/L and 5.97 mg/L, respectively. (ii) The alpha diversity indices of the sediment bacterial community showed a monotonically increasing trend, with the lowest value in the BS. Cyanobacterial blooms reduced the relative abundance of Actinobacteria and Chloroflexi, and raised that of Firmicutes, Proteobacteria and Bacteroidetes. (iii) Cyanobacterial blooms remarkably decreased the complexity of the co-occurrence network of the sediment bacterial community, which resisted extreme environmental conditions in the BS and DS by increasing positive relationships. (iv) Mantel test showed that phytoplankton biomass, T, dissolved oxygen and organic carbon had significant effects on the sediment bacterial community. The results of this study are important for the ecological management of algal blooms through microorganisms.

Isotopic evidence of autochthonous organic matter acting as a major sink of anthropogenic heavy metals in modern lacustrine sediments

The knowledge of major sources, sinks, and the burial fate of various pollutants added to modern aquatic ecosystems under changing environmental conditions is limited but crucial for our sustainability. In this context, the spatial distributions and causative factors of organic matter (OM) and heavy metal accumulations have been explored in modern lacustrine sediments of a large urbanized and protected wetland (ULB: Upper Lake Bhopal) in Central India. For this purpose, geochemical properties, in particular, stable isotopes (δ13C and δ15N) were measured in the ULB surficial sediments (core depth ∼0–1 cm; n = 19), and additionally collected riverbed sediments (n = 2) and atmospheric free-fall dust samples (n = 3) from the lake periphery. The major and trace element data indicate widespread mafic sediment provenance and nearly dysoxic lacustrine conditions. The riverine supply of soil OM from cropped lands and the lake productivity (algae, largely sustained by nutrients from sewage and agricultural runoff) are the major OM sources to the western and eastern lake portions, respectively. The fractional contribution from autochthonous TOC (∼0.19–0.95, mean ∼0.62) predominates that of allochthonous TOC (∼0.05–0.81, mean ∼0.38). Whereas, atmospheric dust deposition is a primary anthropogenic source of heavy metals (Pb and Zn). The lake productivity rather than soil OM or any mineral sorbent is found responsible for the anthropogenic enrichments of Pb and Zn in the ULB surficial sediments, especially on the eastern ULB portion under high anthropogenic pressure. Therefore, the settled OM (primarily autochthonous) being oxidizable acts as a temporary but major sink of anthropogenic heavy metals in modern lacustrine sediments, which are vulnerable to heavy metal efflux to the water column by sediment diagenesis.