Invasive snails, parasite spillback, and potential parasite spillover drive parasitic diseases of Hippopotamus amphibius in artificial lakes of Zimbabwe

Background Humans impose a significant pressure on large herbivore populations, such as hippopotami, through hunting, poaching, and habitat destruction. Anthropogenic pressures can also occur indirectly, such as artificial lake creation and the subsequent introduction of invasive species that alter the ecosystem. These events can lead to drastic changes in parasite diversity and transmission, but generally receive little scientific attention. Results In order to document and identify trematode parasites of the common hippopotamus (Hippopotamus amphibius) in artificial water systems of Zimbabwe, we applied an integrative taxonomic approach, combining molecular diagnostics and morphometrics on archived and new samples. In doing so, we provide DNA reference sequences of the hippopotamus liver fluke Fasciola nyanzae, enabling us to construct the first complete Fasciola phylogeny. We describe parasite spillback of F. nyanzae by the invasive freshwater snail Pseudosuccinea columella, as a consequence of a cascade of biological invasions in Lake Kariba, one of the biggest artificial lakes in the world. Additionally, we report an unknown stomach fluke of the hippopotamus transmitted by the non-endemic snail Radix aff. plicatula, an Asian snail species that has not been found in Africa before, and the stomach fluke Carmyerius cruciformis transmitted by the native snail Bulinus truncatus. Finally, Biomphalaria pfeifferi and two Bulinus species were found as new snail hosts for the poorly documented hippopotamus blood fluke Schistosoma edwardiense. Conclusions Our findings indicate that artificial lakes are breeding grounds for endemic and non-endemic snails that transmit trematode parasites of the common hippopotamus. This has important implications, as existing research links trematode parasite infections combined with other stressors to declining wild herbivore populations. Therefore, we argue that monitoring the anthropogenic impact on parasite transmission should become an integral part of wildlife conservation efforts. Graphical abstract

CLASSIFICATION AND IDENTIFICATION OF ARTIFICIAL LAKES BASED ON NATIONAL GEOGRAPHIC-CONDITIONS DATA

In recent years, the issue of violations or over-exploitation in artificial lake projects have attracted gradual concern. In the initial stage, in order to determine whether there are violations or over-exploitation in the artificial lake project, it is necessary to accurately identify the status of artificial lakes. Because of the relative lack of water resources along the Yellow River, issues such as the contradiction between supply and demand as well as the protection of ecological environment have become increasingly prominent. Besides, the situation of development of artificial lakes along the Yellow River has become serious, increasing the pressure of utilizing water resources along the Yellow River. Therefore, the identification of status of artificial lake is of great significance in ecological supervision of the Yellow River.Under this context, this paper takes the Yellow River as the research area. Based on the land cover data in the multi-temporal geographic national conditions, using spatial analysis, automatic identification and manual differentiation etc., to develop a rapid classification system of artificial lakes to classify the artificial lakes along the Yellow River, tracking and analyzing its annual changes, and finally establishing an artificial lake classification database and an artificial lake change database. Realizing the effective identification and supervision of changes in the artificial lake. Through experiments and analysis of existing data, this paper summarizes a set of indicators for determining the characteristics of artificial lakes, and proposes a set of effective artificial lake identification approaches. It provides an important basis for the follow-up supervision of artificial lake, and also establishes a basic framework for identifying other surface geographic-conditions, which has important theoretical and practical significance in the application of national geographic-conditions data.

The Effects of Artificial Lake Space on Satisfaction and Restorativeness of the Overall Environment and Soundscape in Urban Parks

Several studies have proven that soundscape in blue space is conducive to human health and well-being, but few studies have explored which blue space characteristics would contribute to a better soundscape and visiting experience. Therefore, an on-site questionnaire investigation was conducted at two artificial lakes in Xi’an, China. The eight Perceived Sensory Dimensions (PSDs) as a landscape assessment tool were applied to identify the characteristics of artificial lake space in urban parks. The results showed that (1) In artificial lake space, overall environment and soundscape reached a very satisfactory level in general, while the respondents’ perceived level of overall restorativeness and soundscape restorativeness as just medium, which indicated that the quality of artificial lake space needs to be improved. (2) According to people’s perceptions, artificial lake spaces had the most obvious characteristics of prospect, social and space; serene and nature were medium; refuge, rich in species, and culture were the least. (3) The eight PSDs of artificial lake space, except for social, were positively correlated with soundscape satisfaction, overall satisfaction, soundscape restorativeness, and overall restorativeness. Moreover, among them, serene was the most significant characteristic in artificial lake space. These findings could be instructive to the design of urban parks with artificial lakes for improving users’ visiting satisfaction and restorativeness.

Analysis of Late Pleistocene megafauna and puparia from the Lent dredging site, province of Gelderland (the Netherlands)

More than 900 vertebrate bones, ranging from Late Pleistocene to Holocene in age, have been identified in a collection that was recovered by a single dredging operation for the construction of artificial lakes near Lent (Nijmegen, province of Gelderland, the Netherlands). The Late Pleistocene assemblage comprises mainly Weichselian glacial fauna such as mammoths, reindeer and bison. Some Eemian fauna is represented as well, e.g. straight-tusked elephant. The abundance of certain species over others suggests that preservation bias had a considerable impact on this assemblage, while its time-averaged nature resulted in overrepresentation of certain species. A case study is here conducted on a fragmentary skull of a subadult woolly mammoth bull with embedded blowfly puparia. Some of these puparia are fully developed, indicating prolonged exposure of the mammoth carcass.

Floating PV in mountain artificial lakes: a checklist for site assessment

Floating photovoltaics is a emerging approach to deploy photovoltaics on water bodies. Thanks to its high overall global potential and the extensive experience gained (with more than 2 GWp installed and than 510 plants, up to 2020), it represents a promising venue for expanding renewable electricity production worldwide. However, a local assessment for sustainability is needed for this potential to be converted into specific projects attracting the attention of stakeholders. This paper provides an original and wide-ranging screening checklist that allows for site assessment, with a view of separating suitable from unsuitable sites and emphasising that appropriate design can solve difficulties linked to the site features. It offers an extensive list of activities that international, national and regional authorities, investors, solution providers, local communities and civic society, environmentalists and other stakeholders might undertake for a fruitful dialogue. It explores the possibility that art, architecture and industrial design may play a role in increasing the touristic value and the public acceptance of new plants. Although the checklist can be used in other conditions, a particular attention is paid to mountain artificial lakes used as reservoirs by hydro-power plants, since they have potential high synergies (and a global potential of over 3.0 TW) but also may encounter significant implementation issues.

A New Finding of the Non-Native Copepod Sinodiaptomus sarsi (Copepoda, Calanoida, Diaptomidae) in Ukraine

Sinodiaptomus sarsi is found for the second time in Ukraine, in the three artificial lakes of the one of capital Kyiv city`s park, Nyvky, after its first record in the Carpathian Mountain region near Slovakian border in 2016 by Dr. Mykitchak. Our morphological study showed the similarity between the specimens of S. sarsi found in Kyiv with existing illustrations and descriptions of the Asian population of this species. The most likely route of penetration is human intentional release. Some diagnostic details are discussed and short redescription of species is presented in the paper.