Physiological and Ecosystem Effects of Natural UV-B Radiation on Coastal Primary Productivity

EPA Grant Number: GF9502453
Title: Physiological and Ecosystem Effects of Natural UV-B Radiation on Coastal Primary Productivity
Investigators: Evens, Terence
Institution: University of California - Davis
EPA Project Officer: Packard, Benjamin H
Project Period: September 1, 1995 through January 1, 2000
Project Amount: $24,425
RFA: STAR Graduate Fellowships (1995) Recipients Lists
Research Category: Academic Fellowships , Ecological Indicators/Assessment/Restoration , Fellowship - Ecology


There are three primary objectives for this proposed project. A description of each of the three objectives is followed by a brief description of the approach. The first objective is to extend the mechanistic studies of photoinhibition and UV inhibition of primary productivity initiated at the University of California laboratory. The target sites for UVB regulation in local waters will be identified. The primary focus will be on photoinhibition of photosynthesis with the first test modeled on that of Kroon, using Pulse-Amplitude-Modulation fluorimetry techniques. Following this, there will be genetic analysis of DNA damage following procedures outlined by Jovine and Prezelin.

The second objective is to assess the impact of fluctuating ozone levels (and resulting UVB fluctuations) on primary productivity at temperate latitudes. To accomplish this, a long term database of biweekly measurements of UV sensitivity of regional phytoplankton communities to discern the seasonal variables in sensitivity; discern the most sensitive phytoplankton groups; and create a bio-optical database for natural communities to derive and test models.

The third objective is to develop biological weighing functions for temperate latitude phytoplankton, and compare these studies with work in other aquatic ecosystems in order to develop accurate bio-optical models for general use. Combining spatial and temporal data for UVB dose rates with the appropriate biological weighing functions for UV inhibition of temperate phytoplankton will provide the necessary information required for models to predict the direction and magnitude of UVB induced changes. These can then be compared with models developed for other ecosystems.

Supplemental Keywords:

RFA, Scientific Discipline, Ecosystem Protection/Environmental Exposure & Risk, Ecology, exploratory research environmental biology, Environmental Chemistry, Ecosystem/Assessment/Indicators, Ecosystem Protection, Ecological Effects - Environmental Exposure & Risk, Atmospheric Sciences, Ecological Risk Assessment, Ecology and Ecosystems, Ecological Indicators, coastal ecosystem, physiological effects, coastal primary productivity, ecosystem effects, phytoplankton, primary productivity, aquatic ecosystems, ecosystem response , ozone flux, UV-B radiation

Progress and Final Reports:

  • 1996
  • 1997
  • 1998
  • 1999
  • Final