Cyanobacteria as Bioindicator of Water Pollution

Abstract

Water pollution is a global problem in recent times, and its remedy has become imperative to safeguard the health of ecosystems and humans. To solve the water pollution problem, detecting the presence of various pollutants in water is the first critical step. Although many physical and chemical techniques have been developed to date to measure the concentrations of different types of contaminants in the water, the biological methods are the most feasible due to their easy operational process and cost-effectiveness. The cyanobacteria, a unique group of photoautotrophs known to occupy various aquatic environments, are the potent candidates for detecting the presence of different types of pollutants in water. Due to their common occurrence in water bodies, toxicological responses of cyanobacteria have widely been investigated, which suggests that toxicological research on cyanobacteria may help us evaluate the levels of various contaminants in water bodies because they respond to different pollutants in distinct manners, either by modulating their morphological, ultrastructural, and physiological indices or by changing their community composition and altering molecular biological phenomena. However, water pollution is becoming very complex daily because new pollutants are being produced and discharged daily. Therefore, the toxicological responses of cyanobacteria must be assessed against both existing and emerging contaminants to be used as bioindicators for both kinds of pollutants. In the present chapter, we initially provided glimpses of the status of global water pollution and the types of major water pollutants, followed by discussing bioindicators’ advantages over other traditional methods in determining water pollution. Besides, the chapter also included information on the potential of cyanobacteria as bioindicators of water pollution and detailed descriptions of the cyanobacterial bioindicator characteristics for specific pollutants. Eventually, the chapter suggested that investigating the toxicological impacts of emerging contaminants like pharmaceuticals and aromatic pollutants on cyanobacteria and the selection of unique and distinct bioindicator characteristics will be helpful to better predict the presence of these pollutants in aquatic systems.