SS1.04 Small-scale Biophysical Coupling in Plankton Ecology
Date: Thursday, June 13, 2002
Time: 5:00:00 PM
Location: Esquimalt
DowerJF, University of Victoria, Victoria BC, Canada,
Miller, T, J, Chesapeake Biological Lab, Solomons MD, USA,
Waking up in an inertial world: Linking small-scale physics and metamorphosis in larval fish
Patterns of survivorship in marine fish generally follow an exponential decay during the early larval stages, before leveling off somewhere around metamorphosis. In general, we believe that this widespread pattern reflects the fact that most yolk-sac and early stage larvae are rather helpless and are subject to the combined negative effects of (i) starvation, (ii) predation and/or (iii) advective losses. However, this still doesn't explain why survivorship often increases around metamorphosis in many species. In this talk we will explore the potential for small-scale physical processes to contribute directly to the survival of larval fish at or around the time of metamorphosis. Consider the fact that, during their earliest life-history stages, larval fish inhabit a very viscous world. At some point, however, they finally achieve a size enabling them to move from the viscous into the inertial regime. Specifically, we will examine whether "waking up in an inertial world" has ontogenetic ramifications for larval foraging, predator avoidance and respiration rates that may serve to make post-metamorphs ecologically more efficient and less prone to density independent processes than early stage larvae.