Collaborative Research: Flow and Nutrient Exchange Driven by Pulsating Coral

University Of California - Merced, Merced CA

Investigators

Abstract

Coral ecosystems are of significant interest to conservationists because of their remarkable diversity. Coral reefs, in comparison to colonies of soft corals, are composed of hard corals with calcium carbonate skeletons. One significant difference between the two corals is that the soft coral of the family Xeniidae actively pulse, and this energetically expensive behavior has been shown to enhance photosynthesis rates by an order of magnitude. The central goal of this proposal is to describe how these active movements might give soft coral a competitive advantage through augmented photosynthetic rates under certain environmental conditions. The broad focus of this project is to determine how active movements of flexible organisms enhance particle capture and nutrient exchange. In particular the PIs will study species of the family Xeniidae, the pulsing soft corals, using a combination of mathematical modeling and experiments. This work will develop mathematical models to represent poroelastic structures representative of the feathery tentacles of the corals. The PIs will also develop adaptive numerical methods for handling the flux of nutrients at these moving elastic boundaries. Two graduate students and four undergraduates will be trained at the interface of scientific computing, mathematical modeling, and experimental biology. The PIs willrecruit a diverse group of undergraduate students through established mechanisms at each institution. Several educational activities will be implemented to promote computation in biophysics, including the development of quantitative biology labs. The following specific aims will be addressed in this project: Aim 1: Determine how the pulsing dynamics of a single polyp affects the bulk transport of fluid past the organism and the small scale mixing around the surface of the organism. Aim 2: Determine how the pulsing action enhances particle capture, the exchange of nutrients, and removal of waste. Aim 3: Determine whether or not the group pulsing dynamics are optimized for exchange using network analysis and computational fluid dynamics.