Hydrodynamics of larval settlement: The influence of turbulent stress events at potential recruitment sites

Limnology and Oceanography
By: , and 

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Abstract

We describe a laboratory investigation into the effect of turbulent hydrodynamic stresses on clam larvae in the settlement phase of the recruitment process. A two-component laser-Doppler anemometer (LDA) was used to measure time histories of the instantaneous turbulence structure at potential recruitment sites within reconstructed beds of the adult Asian clam, Potamocorbula amurensis. Measurements were made for two flow speeds over beds with three different clam densities and two different clam heights. We analyze the statistical effect of the turbulence on the larval flux to the bed and on the probability of successful anchoring to the substrate. It is shown that the anchoring probability depends on the nature of the instantaneous stress events rather than on mean stresses. The instantaneous turbulence structure near the bed is altered by the flow rate and the spacing and height of adult clams living in the substrate. The ability to anchor quickly is therefore extremely important, since the time sequence of episodic turbulent stress events influences larval settlement success. The probability of successful larval settlement is predicted to decrease as the spacing between adults decreases, implying that the hydrodynamics impose negative feedback on clam bed aggregation dynamics.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Hydrodynamics of larval settlement: The influence of turbulent stress events at potential recruitment sites
Series title Limnology and Oceanography
DOI 10.4319/lo.2002.47.4.1137
Volume 47
Issue 4
Year Published 2002
Language English
Publisher Association for the Sciences of Limnology and Oceanography
Contributing office(s) Pacific Regional Director's Office, San Francisco Bay-Delta, Toxic Substances Hydrology Program
Description 15 p.
First page 1137
Last page 1151
Online Only (Y/N) N
Additional Online Files (Y/N) N