Hong Kong is one of the most densely populated cities in the world, with millions of people exposed to severe air pollution. (1) Background: Surface ozone, mostly produced photochemically from anthropogenic precursor gases is harmful to both human and vegetation. The phytotoxicity of ozone has been shown to damage plant photosynthesis, induce early leaf death and retard growth. (2) Methods: We use genotypes of bush bean Phaseolus vulgaris with various degrees of sensitivity to ozone to investigate the impacts of ambient ozone on the morphology and development of the bean. We use ozone-induced foliar injury index and measure the flowerings and fruit production to quantify the ozone stress on the plants. (3) Results: We expected that the ozone-sensitive genotype would suffer from a reduction of yield. Results however show that the ozone-sensitive genotype suffers higher ozone-induced foliar damage as expected but produces more pods and beans and heavier beans than the ozone-resistant genotype. (4) Conclusions: It is postulated that the high ozone sensitivity of the sensitive genotype causes stress-induced flowering and therefore results in higher bean yield. A higher-than-ambient concentration of ozone is needed to negatively impact the yield production of the ozone-sensitive genotype. This study demonstrate the usefulness of bioindicators to monitor the phytotoxic effects of ozone pollution in a subtropical city such as Hong Kong.

Molluscs are significant species in aquatic ecology. Molluscs are crucial for maintaining ecological balance as secondary consumers and serving as bioindicator species in biomonitoring systems. Molluscs are threatened by pesticides such as commonly used pyrethroid insecticides. Pyrethroids are typical insecticides used to control insects in agriculture and gardening. Pyrethroids are increasingly being utilized in both agricultural and human activities. Pyrethroids enter aquatic bodies through rainfall and drainage systems. The use of pyrethroids is becoming a significant concern for aquatic creatures, particularly molluscs. The discussion will focus on the increasing issue of pyrethroids becoming a nightmare for molluscs. Pyrethroids, due to their lipophilic nature, pose a significant risk to molluscs by affecting their metabolites, producing reactive oxygen species, and influencing neurotransmitter actions. Molluscs are crucial organisms in aquatic ecosystems, and their threats warrant significant discussion and attention. This review will delve into the behaviour of pyrethroids on molluscs.

In Bangkok, the capital city of Thailand, air pollution is a significant problem, and efforts are needed to define organisms that may be used as bioindicators of air pollution. Epiphytic subaerial algae, which grow on the surface of trees, may have a potential as bioindicators of urban air quality. Algae were collected from randomly selected tree trunks in five parks in Bangkok, and the air pollutants CO, NO2, O3, SO2, PM2.5, and PM10 were measured. Analysis of the subaerial algal communities was performed by metagenomics. Diversity indexes were determined for the algal taxa detected, which were separated into groups corresponding to different collection sites by cluster analysis. Relationships between taxa and air pollutants were analyzed by PCA and the Pearson correlation coefficient (r). The results showed a high diversity of epiphytic subaerial al-gae. We recorded 101 taxa belonging to the Cyanophyta (70 taxa), Chlorophyta (21 taxa), Char-ophyta (5 taxa), Bacillariophyta (3 taxa), and Eustigmatophyta (2 taxa). The most abundant taxon was Chroococcidiopsis sp. 1, for which up to 13,254 individuals/cm2 were recorded. The Shan-non–Weaver index ranged between 1.37 and 2.51, the Margalef index between 3.84 and 4.75, and the Pielou index between 0.30 and 0.54. The similarity index was between 8.00% and 64.82% ac-cording to the cluster analysis results for three groups. The PCA indicated that all air pollutants affected the diversity and abundance of the epiphytic subaerial algae. Cyanothece sp. 2 is consid-ered a potential bioindicator of air pollution. It was negatively related to O3 and positively related to NO2 and CO

The objective of this work was to analyze the potential of Rhizophora mangle as a bioindicator of seven heavy metals, Fe, Cu, Zn, Mn, Ni, Cr, and Cd, in the mangrove sediments of the Navachiste lagoon complex (NAV). The concentration of trace metals (TM) in sediments and tis-sues (leaf, stembark, and root of R. mangle) were determined by digestion with nitric acid (HNO3), whereas the metal absorbance was measured by atomic absorption spectrophotometry with an air-acetylene flame. The enrichment factor, the bioavailable fraction, the seasonal varia-tion of heavy metal concentrations and their correlation with those determined in R. mangle tissues were assessed. Metal concentrations found in sediments were as following: Fe>Mn>Zn>Cr>Ni>Cu>Cd, and for tissues: Mn>Fe>Zn>Cu>Cr>Ni>Cd, and regarding the roots, the findings were as following: Fe>Mn>Zn>Cu>Cr>Ni>Cd. The highest trace metal concentra-tions were correlated with silt, clay, and organic matter in sediments with basic pH. The highest salinities were found adjacent to R. mangle trees. Of all the trace metals analyzed, there was only a positive linear regression between the bioavailability of Mn in the sediment with the concen-tration of Mn in leaf tissue consistently throughout the year. The Cu bioavailability in the sedi-ment showed similar positive linear regressions except for winter, where it did not show this pattern. These results suggest that the concentrations of Mn and Cu in the R. mangle leaf could be a potential bioindicator of environmental exposure to anthropogenic sources of contamination by these trace metals in sediments

The altitude of the habitat is one of the important regulators of species survival. Kaçkar Mountains National Park is located in the Eastern Black Sea region of Turkey. This is the first study on the benthic diatom flora of the high mountain lakes in Kaçkar Mountains National Park, which is situated between 2782 and 3075 m a.s.l. A total of 84 diatom species were identified from benthic communities of 15 habitats in summer (19 July, 28 August) and autumn (10 September) months of 2020. The genus Pinnularia (13 species) formed the basis of the taxonomic list followed by Eunotia (5 species), Navicula (5 species), and Frustulia (4 species) genera, respectively. The waters in all the studied lakes were fresh, low-saline, with low-alkaline or circumneutral pH and organically uncontaminated as evidenced by prevailed bioindicator groups. Statistical methods and comparative floristic results confirm the role of the lake altitude for the diatom species distribution. Species richness was higher in lakes with lower altitude, but a statistical approach also revealed a tendency for it to increase with altitude if species richness increased. Further studies will be needed to continue exploring this pattern. In the first round of analysis, diatom species groups were categorized according to IUCN categories, revealing one potentially threatened and one rare species. To protect studied high mountain lakes, their ecological conditions must be constantly monitored in the Kaçkar Mountains National Park.