UV Radiation

The Impact of UV Radiation on Trophic Interactions in Lakes (and the Ocean)

Biologically damaging UV-B has increased at temperate as well as polar latitudes in response to stratospheric ozone depletion. Damage from UVR has been documented in a wide variety of organisms, ranging from bacteria to plants to invertebrates and vertebrates, but less is known about the indirect effects of UVR and how it influences biotic interactions.  The effects of UVR are highly wavelength specific.  For example, while shorter wavelength UV-B is generally damaging, the longer wavelength UV-A radiation (320-400 nm) may be either damaging or beneficial.  Both positive and negative responses to environmental increases in UVR are thus possible, and the magnitude of the responses will be highly dependent upon the spectral composition as well as the intensity of the UVR.

My lab was involved in a collaborative NSF-funded project, supported by the Integrated Research Challenges in Environmental Biology (IRCEB) program, with several researchers from nine institutions.  The project investigated interactive effects of UV radiation and temperature at levels of organization from molecular to the ecosystem.  The team web page, Interactive Effects of UV Radiation and Temperature on Pelagic Foodwebs, was developed as a site for public outreach, and linked to information contributed by all of the collaborators as the project progressed from its starting date.

My laboratory conducted a series of laboratory and field experiments where we manipulated factors that altered the wavelengths of UVR to which organisms were exposed.  The laboratory experiments defined the wavelength-specific UVR response of individual species from different trophic levels as well as their ability to use photoreactivation versus photoprotection to reduce UVR damage. Our field experiments, including the use of 8 m3 mesocosms, have addressed how different trophic levels respond as a community under scenarios of different UV, temperature,  and dissolved organic carbon levels.  Links to the group’s publications during the grant and other information is available at the link above. Some more recent publications on UVR are found in the publications link on my homepage.

NSF_logoThis work was supported by the National Science Foundation under Grant No. 0210972.  Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author and do not necessarily reflect the views of the National Science Foundation.