Cyanobacterial Diversity and Physicochemical Characteristics of Thermal Springs in The Kütahya Province of Turkey

Thermal springs are very difficult environments for organisms due to the high temperature, and physicochemical parameters. Cyanobacteria, which are photosynthetic prokaryotes, are best adapted to these environments. Kütahya is an important thermal area in Turkey. The aim of the study was to determine the cyanobacterial flora with a morphologic and ecologic approach in the 11 thermal. The physicochemical properties of the thermal springs in Kütahya province were measured. The thermal springs are alkaline (pH6) with an average temperature of 52°C. As a result, 54 cyanobacteria taxa were identified. Oscillatoriales were the predominant order in terms of taxa diversity (24 taxa) and biomass size. Statistical analyses were conducted to reveal the physicochemical properties of the thermal springs and the distribution of cyanobacteria in detail. According to these analyses, the thermal springs were classified into two main groups with a Piper. As a result of the RDA analysis under CANOCO 5.0, the total variation was 55.45455, and the first two axes explained a total of 57.43% of the variance. There was a significant difference (P0.001) in the comparison of the physicochemical parameters including pH, EC, TDS, and temperature values of the thermal springs in the Kruskal Wallis tests. Bangladesh J. Plant Taxon. 28(2): 413-428, 2021 (December)

Hydrogeochemistry and Precursory Anomalies in Thermal Springs of Fujian (Southeastern China) Associated with Earthquakes in the Taiwan Strait

Analyzing the hydrochemical composition in thermal springs is an advantageous method for studying the coupling mechanism of the deep and shallow fluids in active fault zones. Here we conducted sampling in 30 thermal springs near fault zones in Fujian Province, and the major elements, trace elements, silica, stable isotopes (δD and δ18O) and strontium isotopes were tested in the laboratory. The results show that (1) the thermal springs in the study area can be divided into six types according to the content of the major elements: HCO3-Na, HCO3·SO4-Na, Cl·HCO3-Na, Cl-Na, Cl-Na·Ca and HCO3·SO4-Ca; (2) hydrogen and oxygen isotopes indicate that precipitation is the main source of recharge for thermal springs in the study area, and the recharge height is between 258 m and 1859 m; (3) the content of SiO2 in the thermal spring varies from 18.1 mg/L to 59.3 mg/L. The geothermal reservoir temperature calculated is 90~226 °C, and the circulation depth is 2.9~5.4 km, except for the W10 thermal spring, whose circulation depth is 8.4 km; and (4) the 87Sr/86Sr of the thermal springs in southwestern Fujian and eastern Fujian has obviously different characteristics, indicating the influence of different rock formations on the groundwater cycle process. Additionally, a continuous measurement of the main anions and cations was performed in five thermal springs every three days since January 2020. There were obvious abnormal changes in the hydrochemical compositions, chlorine in four of the five springs, sodium at three springs, and four ions at one spring, which all showed abnormal high-value changes by 15% to 80%, and which occurred 85~168 days prior to the M6.1 earthquake in Hualien, Taiwan. An inspiration could be provided for obtaining effective earthquake precursor anomalies by monitoring the change in ion concentration in thermal springs.

Temperature regime of the Daginsky thermal springs (Sakhalin Island) during their reconstruction in 2019-2021

The article presents the results of studies of the temperature regime of the Daginsky thermal springs. Daginsky thermal springs are the most famous and visited on Sakhalin Island (Russia). In the fall of 2019, their reconstruction and arrangement of the surrounding landscape began. As a result of the reconstruction of the main thermal springs, their hydrological and temperature regime was violated, the water temperature dropped. In 2020, in the springs most popular with visitors (Aleksandrovsky, Tsentralny, Mechta), the temperature became several degrees lower, which led to the termination of their use. In 2021, after the completion of the design of the spring bath and the surrounding area, the temperatures increased. In April 2021, the temperature of the Patriot spring was 40.5 °C, the Partizan spring 38–39 °C, the Central spring 36–39 °C, the Aleksandrovsky spring 34.6–36.0 °C, the Mechta spring 34.4 °C (at the bottom up to 45.5 °C), Molodost spring 35 °C (at the bottom up to 37–41.3 °C).

Motives for Thermal Tourism: An Application to North and Central Portugal

Health and wellness tourism should be particularly valued in the post-pandemic phase. It has the potential to be a strategic product that enhances the population’s well-being and quality of life, on social, physical, and environmental levels. Different proposals for specialized experiences that complement what the destination offers allow to position regions as health and wellness destinations. Thermal tourism should thus be encouraged as a specific product designed on the innovation and diversification observed in the related services and the benefits recognized for all ages. Considering the relevance of thermal springs and thermal tourists for the image, positioning, and development of touristic destinations, this research aims to identify the specific motivations of tourists that attract them to the practice of thermal tourism, to understand how the benefits for which thermal tourists search and their sociodemographic profile influence the motivations of tourists, and how those motivations determine the characteristics of travel. This research was developed on the North and Centre of Portugal for their relevance in the context of thermal springs and related touristic activities. To achieve the research objectives, a questionnaire survey was conducted among thermal tourists, through a non-probability by convenience sampling, using bivariate tests, such as Pearson’s chi-squared test, one-way ANOVA, and t-Student test. The results highlight that most respondents practiced thermal tourism due to leisure and relaxation benefits, such as the escape from daily stress, spend time with family, and being “pampered”; relaxation is the most valued motivation, followed by the search for psychological and physical well-being. The research found relations between the benefits expected by thermal tourists and their travel characteristics, such as the composition of the group, the general travel motivation, the chosen thermal destination, and the number of nights spent at the location. In thermal tourism, new challenges emerge, demanding the development of strategies, products, and services that respond to the needs of specific market sections.

Extremophilic Microorganisms in Central Europe

Extremophiles inhabit a wide variety of environments. Here we focus on extremophiles in moderate climates in central Europe, and particularly in Slovenia. Although multiple types of stress often occur in the same habitat, extremophiles are generally combined into groups according to the main stressor to which they are adapted. Several types of extremophiles, e.g., oligotrophs, are well represented and diverse in subsurface environments and karst regions. Psychrophiles thrive in ice caves and depressions with eternal snow and ice, with several globally distributed snow algae and psychrophilic bacteria that have been discovered in alpine glaciers. However, this area requires further research. Halophiles thrive in salterns while thermophiles inhabit thermal springs, although there is little data on such microorganisms in central Europe, despite many taxa being found globally. This review also includes the potential use of extremophiles in biotechnology and bioremediation applications.

Hydrogeochemistry of the Thermal Springs of Pojqpoquella and Phutina, Puno, Peru

This paper deals with the results of a hydrogeochemical study of two thermal springs that originate from in very high altitudes in southwestern Peru with outflow temperatures of maximal 38,4 °C and flow rates of 1.08 - 2.02 l/s. Water samples from the Pojqpoquella and Phutina geothermal wells, were collected during the period between September 2018 and January 2019 in the main area of Puno. Chemical types of the thermal spring are Na+, Ca2+, Cl- and CO 3 2 − in Ayaviri and Putina. According to the Piper and Schoeller diagrams for the Pojqpoquella thermal spring water is classified as Na++ K+ (75 %) and Cl- (60 %) type water while that of the Phutina thermal spring is classified as Na++ K+ (76 %) and Cl- (72 %) type water. The electrical conductivity (EC) values for the Pojqpoquella and Phutina thermal spring waters is 2160 - 3142 μS/cm and 3160 - 3184 μS/cm, respectively, the thermal spring waters have a high electrical conductivity which shows that it has interacted with the host rock for a long time. The reservoir rocks of the Pojqpoquella thermal system consist of a red sandstones and conglomerate rocks while the reservoir rocks of the Phutina thermal system consist of a thick sequence of cretaceous rocks.

Preliminary Fluid Geochemical Survey in Tete Province and Prospective Development of Geothermics in Mozambique

An evaluation of the feasible development of geothermal energy in Mozambique is proposed based on some thermal springs geochemical characterization in the Tete region. Chemical and isotopic data suggest that the springs have a meteoric origin and do not show connection with any active magmatic system. The proposed circulation model suggests high depths infiltration of meteoric waters along faults and fractures in a system characterised by discrete permeability and reservoir temperature between 90 and 120°C. These results, jointly with low salinity fluids and corrosive components absence suggest that the geothermal system may be conveniently exploited for direct and indirect uses.

Microorganisms of Two Thermal Pools on Kunashir Island, Russia

The Kuril Archipelago is a part of the Circum-Pacific Belt (Ring of Fire). These islands have numerous thermal springs. There are very few studies on these microbial communities, and none of them have been conducted by modern molecular biological methods. Here we performed the first metagenomic study on two thermophilic microbial communities of Kunashir Island. Faust Lake is hot (48 °C) and highly acidic (pH 2.0). We constructed 28 metagenome-assembled genomes as well as 17 16S ribosomal RNA sequences. We found that bottom sediments of Faust Lake are dominated by a single species of red algae belonging to the Cyanidiaceae family. Archaeans in Faust Lake are more diverse than bacteria but less abundant. The Tretyakovsky Thermal Spring is also hot (52 °C) but only weakly acidic (pH 6.0). It has much higher microbial diversity (233 metagenome-assembled genomes; 93 16S ribosomal RNAs) and is dominated by bacteria, with only several archaeans and one fungus. Despite their geographic proximity, these two thermal springs were found to not share any species. A comparison of these two lakes with other thermal springs of the Circum-Pacific Belt revealed that only a few members of the communities are shared among different locations.