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.

Wetlands serve many functions, including conserving water, providing habitats for animals and plants, and regulating climate change. Their unique ecological effects on the natural environment are indispensable in the whole ecosystem. Dianchi Lake Basin is located in Yunnan-Guizhou Plateau, China, and mainly in Kunming. It is a typical plateau urban wetland area. Based on spatio-temporal hotspot mining, spatio-temporal geographically weighted regression, and adaptive multidimensional grey prediction, we conducted correlation analyses of the wetland changes in Dianchi Lake Basin from 1993 to 2020 under the influence of human activities and natural conditions. The results show that (1) the active wetland change zone in Dianchi Lake Basin is mainly located around Dianchi Lake, and (2) the wetlands in some areas on the north and south of Dianchi Lake declined in the early 21st century, but under the protection policy in recent years, the wetlands in these areas gradually recovered. Meanwhile, the wetlands in most areas around Dianchi Lake showed a significant growth trend from 2018 to 2020. The results suggest that the wetland change in Dianchi Lake Basin is mainly related to the urbanization of Kunming, and it can be divided into five regions (strong negative correlation, weak negative correlation, weak correlation, weak positive correlation, and strong positive correlation) according to the different correlation of human activity intensity, among which the main factors affected by nature are different, but they are all related to temperature. This study shows that, although wetlands in plateau cities can be properly restored under proper protection, wetland protection should be kept in step with the development of plateau cities to support sustainable urban development and carbon neutrality.

Urbanisation is known to result in \'urban stream syndrome\', which poses a huge threat to the river health. Birds, which are an important part of the river ecosystem, are sensitive to environmental changes in the basin. The ratio of the impervious surface area is a macroscopic indicator of urbanisation intensity in river basins. In this study, we combined the results of a year-round field survey of seven river wetlands around Chaohu Lake (China) with satellite remote sensing image data from the same period. The species richness at sections of the lake entrance was higher than in the middle sections of the river, and the Shannon-Wiener index during autumn was higher than that during winter. The waterbird diversity index declined exponentially with increases in the intensity of urbanisation. The changes in the land use patterns around river wetlands associated with urbanisation resulted in the loss of food resources and habitats. Therefore, the intensity of urbanisation was an important driving factor that leads to changes in the bird community structure of river wetlands, so it had a significant impact on the diversity of river wetland birds in all four seasons combined with a variety of influencing factors. Our research could be a guide for urban landscape planning and bird diversity protection. For example, the results suggested that it is necessary to identify river wetlands as an important part of the urban ecosystem, reduced building area, increased vegetation coverage, and retained slope protection and river beach land.

Growing conditions of water scarcity and population growth necessitate measures for improved water availability to meet agricultural, industrial, and domestic and consumer water demands; generating new environmental pressures on wetlands and other aquatic ecosystems. In Iran, the \"set-aside program\" incentivizes farmer participation in wetland conservation through mandated land management practices, making them key stakeholders in environmental conservation action. This study explores attitudes to participation in the set-aside wetland conservation program to revive the Jazmurian wetland in Iran, using a random sample of 226 farmer-stakeholder respondents. Farmers were surveyed to investigate economic and social participation using a willingness to accept (WTA) and willingness to pay (in money per ha) (WTP) model. Results show strong (45%) respondent opposition to wetland conservation participation. On the basis of their WTA, the amount of compensation offered by the villagers was significantly affected by \"the cultivated area\", \"gender\", \"education\", \"family size\", \"residency\", \"income\", \"moralism\", and \"Inverse Mills Ratio index\" factors. Also, \"the cultivated area\", \"age\", \"education\", \"marital status\", \"family size\", and \"income\" were found to be significantly affecting their WTP. We argue firstly, that policies to improve wetland conservation must join together infrastructure and agricultural development planning - such that dam projects, agricultural and water conservation planning are better integrated across wetland catchments. Secondly, that wetland conservation participation will be improved through land consolidation agreements for small-holders, and through incomes stabilization, capacity building, social learning and awareness-raising initiatives for farmers towards sustainable agricultural practices.

The 2303 Wetlands of International Importance distribute unevenly in different continents. Europe owns the largest number of sites, while Africa has the largest area of sites. More than half of the sites are affected by three or four impact factors (55%). The most significant impact factors are pollution (54%), biological resources use (53%), natural system modification (53%), and agriculture and aquaculture (42%). The main affected objects are land area and environment of the wetlands, occurred in 75% and 69% of the sites, respectively. The types most affected by land area occupation are river wetlands and lake wetlands, the types with the greatest impact on environment are marine/coastal wetlands and river wetlands, the type with the greatest impact on biodiversity is river wetlands, the types most affected by water resources regulation are marsh wetlands and river wetlands, and the types most affected by climate change are lake wetlands and marine/coastal wetlands. About one-third of the wetland sites have been artificially reconstructed. However, it is found that the proportions of natural wetland sites not affected or affected by only one factor are generally higher than that of wetland sites both containing natural wetlands and human-made wetlands, while the proportions of wetland sites both containing natural wetlands and human-made wetlands affected by three or four factors are generally higher than that of natural wetland sites. Wetland sites in the UK and Ireland are least affected among all countries. Wetland management plans in different regions still have large space for improvement, especially in Africa and Asia. The protection and restoration of global wetlands can be carried out in five aspects, including management and policy, monitoring, restoration, knowledge, and funding.