Individual-based model of larval transport to coral reefs in turbulent, wave-driven flow: behavioral responses to dissolved settlement inducer
Authored by M A R Koehl, J A Strother, M A Reidenbach, J R Koseff, M G Hadfield
Date Published: 2007
DOI: 10.3354/meps335001
Sponsors:
United States National Science Foundation (NSF)
Platforms:
No platforms listed
Model Documentation:
Other Narrative
Mathematical description
Model Code URLs:
Model code not found
Abstract
Larvae of many benthic marine animals settle and metamorphose in
response to waterborne chemical cues. Can the behavioral responses of
microscopic larvae in the water column to dissolved chemical cues affect
their transport to the substratum in the turbulent, wave-driven flow
characteristic of many shallow coastal habitats? We addressed this
question using an individual-based model of larvae of the sea slug
Phestilla sibogae, transported in the oscillatory flow above coral
reefs. Larvae of P. sibogae stop swimming and sink in response to a
dissolved inducer released by their prey, the coral Porites compressa, and resume swimming when exposed to inducer-free water. The
instantaneous fine-scale spatial distribution of inducer in the flow
above a reef is filamentous; hence microscopic larvae swimming or
sinking through the water encounter inducer above threshold
concentration in on/off temporal patterns. Model results show that using
a time-averaged inducer concentration gradient to calculate larval
transport rates to the reef overestimates the rates by < 15\% (depending
on the threshold concentration of inducer required to trigger larval
sinking) compared with those calculated using time-varying, fine-scale
inducer distributions. Aspects of larval behavior that have large
effects on rates of transport to the substratum are swimming speed and
direction, sinking speed, and sensitivity (threshold concentration) and
responsivity (percent of encounters eliciting a response) to inducer. In
contrast, lag times to start sinking after encountering inducer or to
resume swimming after re-entering inducer-free water, have negligible
effect.
Tags
Crassostrea-virginica larvae
Water-flow
Imaging velocimetry measurements
Dispersing benthic organisms
Nudibranch phestilla-sibogae
Gradient
tensor field
Suspended particles
Planktonic larvae
Boundary-layer
Odor plumes