High-frequency sampling and piecewise models reshape dispersal kernels of a common reef coral.

Abstract

Models of dispersal potential are required to predict connectivity between populations of sessile organisms. However, to date, such models do not allow for time-varying rates of acquisition and loss of competence to settle and metamorphose, and permit only a limited range of possible survivorship curves. We collect high-resolution observations of coral larval survival and metamorphosis, and apply a piecewise modeling approach that incorporates a broad range of temporally varying rates of mortality and loss of competence. Our analysis identified marked changes in competence loss and mortality rates, the timing of which implicates developmental failure and depletion of energy reserves. Asymmetric demographic rates suggest more intermediate-range dispersal, less local retention, and less long-distance dispersal than predicted by previously employed non-piecewise models. Because vital rates are likely temporally asymmetric, at least for nonfeeding broadcast-spawned larvae, piecewise analysis of demographic rates will likely yield more reliable predictions of dispersal potential.