Fungal diseases, such as saprolegniasis, are common in the aquaculture sector and natural environment, but effective methods to prevent disease outbreaks have yet to be developed. The entry of chemical substances into the environment leads to increasing environmental pollution, which promotes the adaptation of pathogenic organisms to environmental changes. Currently, little is known about the impact of environmental pollutants on the (patho)biology of stramenopilous fungi. Considering that many species of stramenopilous fungi are causative agents of destructive diseases and environmental pollution can influence their pathogenicity (hormesis, pollution-induced synthesis of mycotoxins), knowledge about changes in pathogenicity in the context of environmental pollution (“something from nothing” phenomenon) becomes of great importance.
The dissertation will cover the identification of stramenopilous fungi in fish farms and natural water bodies, the assessment of pathogenicity of isolated species to salmonid fish, changes in pathogenicity in the context of environmental pollution, and research on the induced biological effects. To obtain a comprehensive assessment of the biological effects caused by (a)biotic factors, studies will be carried out using cytogenetic, physiological, and biochemical biomarkers. Stramenopilous fungi will be isolated from water samples, and the isolates will be cultured and identified to the species level using morphological and molecular methods (analysis of the rDNA ITS gene region). The research aims to acquire novel scientific insights into the interactions among pathogenic stramenopilous fungi, fish, and pollution within aquatic ecosystems. It seeks to examine the ecotoxicological consequences for fish, assess the fundamental mechanisms contributing to saprolegniasis outbreaks in relation to (a)biotic factors, and evaluate the susceptibility of both artificially bred and wild salmonid fish to (a)biotic factors and their synergistic impacts. The investigation will identify and compare the species diversity of stramenopilous fungi between salmonid fish farms and salmonid rivers. The findings will provide valuable insights for refining existing guidelines on assessing the environmental impact and risk posed by multiple stressors. Furthermore, they can aid in enhancing monitoring programs for water pollution effects on ecosystems by integrating biomarkers of biological effects and formulating or enhancing measures to mitigate the adverse environmental consequences of aquaculture.