Climate-Mediated Shifts in Hurricane Characteristics: Large-Scale Ecological Effects on Coral ReefsEPA Grant Number: U915144
Title: Climate-Mediated Shifts in Hurricane Characteristics: Large-Scale Ecological Effects on Coral Reefs
Investigators: Kerr, Alexander M.
Institution: Yale University
EPA Project Officer: Hahn, Intaek
Project Period: September 1, 1997 through August 1, 2000
Project Amount: $102,000
RFA: STAR Graduate Fellowships (1997) RFA Text | Recipients Lists
Research Category: Academic Fellowships , Ecological Indicators/Assessment/Restoration , Fellowship - Ecology and Ecosystems
The overall objective of this research project is to begin understanding potential climate-induced shifts in storm disturbance to marine ecosystems, I propose to examining the role of wave disturbance in maintaining oceanic-basin-wide patterns of ecological diversity in scleractinian corals in the western Pacific Ocean. This region is experiencing the widest range of return times of cyclonic storms in the world. The specific objectives of this research project are to: (1) examine the relationship between hurricane features (intensity, frequency, and temporal spacing) and the population demographics of corals with contrasting expected responses to disturbance?; and (2) examine the contribution of factors (depth, colony size, colony shape, reef aspect to swell, and recovery time) mediating this interaction.
First, I will develop a time-integrated picture of significant wave characteristics in shallow water for any given reef,. I will incorporatinge the effects of bathymetry, shoaling, and refraction on deep water waves estimated from 50 years of archived meteorological data on cyclonic storms in the western North Pacific. Much of this involves incorporating standard, previously verified, linear wind- and wave-field equations will be incorporated into a format that allows me to input a site's position and receive, for a given depth, a history of hydrodynamic attributes responsible for storm damage. Then I then will then use the time series to select minimallya minimum of three islands experiencing either high, medium, or low wave disturbance, and around which I will intensively survey the population structure of a hemispherical, a tabulate, and an encrusting coral. I will consider several variables affecting wave-energy transfer, including reef topography, angle of incoming swell, depth, recovery time, colony size, colony morphology, and storm frequency and intensity. Response variables will include clustering, percent cover, and the number of colonies. The data will be analyzed via multivariate regressions and path analysis,; a method that identifies multilevel synergisms and antagonisms between predictors to uncover, among other things, their net effect on the variation of the response. Resulting first- and second-order models parameterized with data from the severely and rarely buffeted islands will then be used to interpolate predicted responses for island(s) experiencing intermediate disturbance.