Grantee Research Project Results
The Effect of Irradiance and Zooplankton on the Stable Carbon Isotopic (d13C) Composition on Scleractinian Corals
EPA Grant Number: U914955Title: The Effect of Irradiance and Zooplankton on the Stable Carbon Isotopic (d13C) Composition on Scleractinian Corals
Investigators: Grottoli-Everett, Andrea G.
Institution: University of Houston
EPA Project Officer: Hahn, Intaek
Project Period: January 1, 1996 through December 7, 1999
Project Amount: $102,000
RFA: STAR Graduate Fellowships (1996) RFA Text | Recipients Lists
Research Category: Fellowship - Oceanography , Fellowship - Aquatic Ecology and Ecosystems , Academic Fellowships
Objective:
The objective of this research project is to
evaluate the effect of solar irradilance and plankton on 13C levels in coral
skeletons to reconstruct
paleoclimate (climate of past ages) changes related to cloud cover and the
extent of upwelling events in the eastern Pacific Ocean.
Approach:
The proposed experiments were designed to test the
following hypotheses: (1) as irradiance increases, skeletal 13C increases;
and (2) as plankton levels
increase, skeletal
13C decreases. A controlled tank experiment was conducted
in Hawaii to grow coral fragments of Porites compressa and P. lobata under
specific light and zooplankon regimes for 4 months. The resulting skeletal
material will be extracted, and the
13C levels will be analyzed. A multiple
linear regression of the data will be used to assess the association between
skeletal
13C, light, and plankton. The resulting predictive model will facilitate
reconstruction of past light and plankton levels based on patterns of the skeletal
13C signature. The model was validated by conducting a field experiment (similar
to the tank experiment); its range of applicability was tested by conducting
a similar field experiment in Florida. The model will be used to reconstruct
cloud cover and upwelling events from published coral isotope records. The
complete reconstruction of tropical paleoclimates and its incorporation into
global climate models (GCMs) are essential to improving the reliability of
GCMs and their powers of global climate prediction.
Supplemental Keywords:
fellowship, stable carbon isotopic composition, scleractinian corals, solar irradiance, plankton, global climate modesl, GCMs., RFA, Scientific Discipline, Air, Ecosystem Protection/Environmental Exposure & Risk, Aquatic Ecosystems & Estuarine Research, Chemistry, climate change, Air Pollution Effects, Aquatic Ecosystem, Monitoring/Modeling, Ecological Risk Assessment, Atmosphere, environmental monitoring, environmental measurement, meteorology, climatic influence, global change, climate, climate models, UV radiation, ecosystem indicators, aquatic ecosystems, environmental stress, coastal ecosystems, plankton, global climate models, coral reef communities, ecological models, climate model, ecosystem stress, solar irradiance, Global Climate Change, atmospheric chemistryProgress and Final Reports:
The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.