Assessing biochemical responses of filamentous algae integrated with surface waters in Yavuzeli-Araban catchment

Abstract

The present study aimed to investigate biochemical responses of filamentous algae integrated with surface waters in Yavuzeli-Araban catchment (the south-east of Turkey) by the use of a multivariate approach. This catchment having anthropogenic activities and different climate could affect environmental variables of surface waters, changed the biochemical compounds of filamentous species. A canonical correspondence analysis elucidated that heavy metals, water temperature, and nutrients were found to be major environmental factors governing the occurrence/succession and biochemical contents of filamentous algae. Cladophora glomerata is mainly linked with water temperature, antimony, orthophosphate, and conductivity, whereas Spirogyra majuscula related to nitrate and lead. Filamentous algae obtained from various sampling stations had different biochemical responses to different physicochemical factors. The biochemical responses of species were significantly different between sampling stations (p < 0.05) at different sampling seasons. Relatively high nutrients and low heavy metal contents stimulated the formation of pigments and total protein content by filamentous algae. On the other hand, increment in heavy metal ions in ecosystems lead to increase malondialdehyde, hydrogen peroxide, proline, total thiol group, and total phenolic compounds by filamentous algae. A significant positive relation between heavy metal ions and mentioned biochemical compounds observed from the Pearson correlation test. Besides, the surface structure of algal biomass changed concerning the different responses of species under various environmental conditions, indicated by the Fourier transform infrared analysis. Filamentous algal species showed different temporal and spatial occurrences in the region, which could be due to the biochemical responses of algae species to different complex environmental conditions. A significant increment in mentioned biochemical compound levels in filamentous algae obtained from a different broad of habitats and their sensitivity/tolerance to the environmental condition could make them valuable bioindicators.