Limnological Characterization of the Tristate Oxbow Wetland (Ohio, Indiana)

Author Institution: Department of Botany, Miami UniversityWe conducted a limnological study in bodies of water (Oxbow Lake, North Pond, Great Miami River, Ohio River) comprising the Tristate Oxbow Wetland region of southwestern Ohio and southeastern Indiana. This wetland, an extensive and important wildlife habitat located at the confluence of the Great Miami River and the Ohio River, is a region that has been and may in the future be impacted by industrial and commercial development. The present data suggest that Oxbow Lake and North Pond are strongly influenced by seasonal flooding patterns and resultant nutrient loading from the Great Miami River and the Ohio River. On the basis of physico-chemical and biological parameters, Oxbow Lake can be classified as a eutrophic to hypereutrophic system, while North Pond is mesotrophic to eutrophic

Four Large River Project ill S. Korea: Ecological Problems, Consequences and Challenges

Article信州大学山地水環境教育研究センター研究報告 6: 10-10(2010)departmental bulletin pape

Effect of Indian Ocean Dipole signal on freshwater cyanobacterial dynamics

The proliferation of freshwater cyanobacteria is a serious environmental problem that often reduces water quality. In this study, we observed the possible influence of the Indian Ocean Dipole (IOD), represented by the Dipole Mode Index (DMI), on the dynamics of cyanobacterial blooms in a river system (the lower Nakdong River). Korean monsoon rainfall (KMR) was preceded by 5-month moving average DMI of ~1.5 years, and the KMR and DMI were negatively associated (r2 = 0.53, n = 15, p < 0.01). In turn, a decrease in KMR was responsible for a decrease in total dam discharge (r2 = 0.64, n = 15, p < 0.01), resulting in an abrupt increase in cyanobacterial cell density at the study site (r2 = n = 15, p < 0.01). We found a strong and significant positive correlation between cyanobacterial density of the Nakdong River and a 5-month moving average DMI (r2 = 0.95, n = 15, p < 0.01). These correlations suggest that a positive DMI decreased KMR and therefore water discharge, resulting in an excessive proliferation of the cyanobacterial density during the monsoon period. Despite a variety of uncertainties, the presence of the IOD is believed to play a role in triggering freshwater cyanobacterial proliferation through a signal propagation pathway during summer drought occurrence in the monsoon period

Testing the strengths of relationships between otter populations, fish and macroinvertebrate communities as well as habitat conditions across three Korean rivers by inferential modelling based on the hybrid evolutionary algorithm HEA

The Eurasian otter Lutra lutra is semi-aquatic carnivore and apex predator in aquatic systems. Since Korean government has implemented comprehensive clean water plans (1989 ~ 1997), improved aquatic food-web structure sustains otter population recovery. In this study, using hybrid evolutionary algorithm (HEA), we would demonstrate the influential food chains to the otter populations. We used 22 chains of the food-web structures (11 water qualities measurements (BOD, NH3N, NO3N, TN, PO4P, TP, water temperature, dissolved oxygen (mg/l), pH, conductivity, and turbidity), Diatom, chlorophyll a, five Macro-Benthic Invertebrates categories (Mollusca, Anthropoda, Annelida, Nematomorpha, and Platyhelminthes), and four fish categories (benthivore, herbivore, planktivore, and piscivores)). According to the 22 chains, we investigated spraint densities (no. spraint per 600m) as otter population indices at 250 sites in Nakdong River basin (NR, 2014-2016, three years), 92 sites in Youngsan River basins (YR, 2016), and 83 sites in Seumjin River basin (SR, 2016). In NR of 2014, otter populations seemingly affected by both micro-invertebrates (r^2 = 0.32) and fish densities (r2 = 0.31). However, overall of NR (2014-16), otter populations have been more precisely expected by fish densities (r^2 = 0.41), other than water quality measurements (r^2 = 0.37), and macro-invertebrates (r^2 = 0.32). In Seumjin and Youngsan River basins, otter populations were more explained by macro-invertebrate (r^2 = 0.40), than fish (r^2 = 0.26) and water qualities measurements (r^2 = 0.28). Different river basins and years showed the different thresholds of different food chains. We concluded that otter population status could result in different sensitivity of chain of food-web structures

A scientometric study of the limnological societies: inferences of research collaboration and core topics based on publication networks

Scientometric analysis of limnological societies and related publications revealed complex relationships among research topics and research collaborations. We applied scientometric analysis, word networks, bibliographic coupling, and author networks analysis, to 34 777 publications related to limnology and monsoon research. We analyzed usage frequencies of limnology-related words in a Google corpus and found that usage frequencies of most limnological terms peaked during the 1980s. Social interest in the term “limnology” showed a gradually decreasing trend after the late 1990s. Monsoon research was focused in the Asian–Indian region but not in the European, African, and American regions. Word networks of limnological studies related to monsoons were mainly grouped into 3 clusters (Indian monsoons, East Asian monsoons, and monsoon assessment clusters). In the citation network of limnology journals, water quality, plankton, and invertebrate research groups generally showed strong internal citation networks. An author connection map of the limnological societies revealed strong modulators in the international societies, whereas research collaboration was rather limited to small groups within the entire network. This retrospective analysis will provide meaningful information to further develop and enhance international collaboration within limnological studies

Effect of Gated Weir Opening on the Topography and Zooplankton Community of Geum River, South Korea

Hydrological changes affect not only the physicochemical factors and habitat structure of river ecosystems, but also the structure of biological communities sensitive to environmental changes, such as zooplankton. In this study, we investigate the effects of weir opening on environmental variables and topographic structures at Sejong Weir in South Korea and monitor the resulting changes in the structure and distribution of the zooplankton community. Weir opening led to increased dissolved oxygen and decreased conductivity, turbidity, chlorophyll a, total phosphorus, and total nitrogen and increased the diversity of topographic structures (reduced pool area and increase riffle and grassland/bare land areas) in the section downstream of Sejong Weir. Prior to weir opening (2015–2016), the cladoceran community was dominated by Chydrous spaeericus and Moina microcopa. After opening (2018–2019), the abundance of other cladoceran communities such as Bosmina groups (Bosmina longiseta, Bosmina fatalis, and Bosminopsis deitersi), Ceriodaphnia sp., and Daphnia obtusa increased. In contrast, the copepod species (Cyclops vicinus and Mesocyclops leukarti) were abundant before weir opening. We conclude that artificial weir opening helped maintain the unique environmental characteristics of the river ecosystem in terms of river continuity and led to a different zooplankton community composition in the new river environment

Talking about Climate Change and Global Warming.

The increasing prevalence of social networks provides researchers greater opportunities to evaluate and assess changes in public opinion and public sentiment towards issues of social consequence. Using trend and sentiment analysis is one method whereby researchers can identify changes in public perception that can be used to enhance the development of a social consciousness towards a specific public interest. The following study assessed Relative search volume (RSV) patterns for global warming (GW) and Climate change (CC) to determine public knowledge and awareness of these terms. In conjunction with this, the researchers looked at the sentiment connected to these terms in social media networks. It was found that there was a relationship between the awareness of the information and the amount of publicity generated around the terminology. Furthermore, the primary driver for the increase in awareness was an increase in publicity in either a positive or a negative light. Sentiment analysis further confirmed that the primary emotive connections to the words were derived from the original context in which the word was framed. Thus having awareness or knowledge of a topic is strongly related to its public exposure in the media, and the emotional context of this relationship is dependent on the context in which the relationship was originally established. This has value in fields like conservation, law enforcement, or other fields where the practice can and often does have two very strong emotive responses based on the context of the problems being examined