Response of algae to increased UV radiation

In flowing waters periphyton algae that develop as biofilms on submersed substrata are exposed to both UV radiation (UVR) and chemical toxicants. In this project, we have examined the effects of enhanced UVR on the adaptation of periphyton to UVR and cadmium. Since metal toxicity, similar to UVR, is related at least in part to oxidative stress, we predicted that adaptation to UVR also confers protection from metals. As expected, algae communities exposed to UVR display increased tolerance to both stressors indicating that defense mechanisms active in the reduction of UVR-mediated oxidative stress might also confer protection from cadmium toxicity. Considering the strong biomass dependence of tolerance to UVR and to cadmium, biofilms adapted to increased UVR conditions might be more susceptible when other stressors enter aquatic ecosystems. However, thin biofilms are more sensitive to stressors than thick biofilms, most probably due to the increased availability of stressors. Thus, UV-induced effects on biomass do alter the sensitivity of periphyton to other pollutants. Another project examines effects imposed by the influence of UVR and in combination with herbicides on algae. See also link to Bioanalytics.

References

Navarro E, Robinson CT & Behra R (2008) Increased tolerance to ultraviolet radiation (UVR) and cotolerance to cadmium in UVR-acclimatized freshwater periphyton. Limnol. Ocean. 53: 1149-1158.

Navarro E, Robinson CT, Wagner B & Behra R (2007) Influence of ultraviolet radiation on UVR-absorbing compounds in freshwater algal biofilms and Scenedesmus vacuolatus cultures. Journal Toxicol. Environ. Health-Part a-Current Issues 70: 760-767.