Physical Sciences and Mathematics Commons^™

Dispersal Dynamics In A Wind-Driven Benthic System, John A. Commito, S. F. Thrush, R. D. Pridmore, J. E. Hewitt, V. J. Cummings

Environmental Studies Faculty Publications

Bedload and water column traps were used with simultaneous wind and water velocity measurements to study postlarval macrofaunal dispersal dynamics in Manukau Harbour, New Zealand. A 12-fold range in mean wind condition resulted in large differences in water flow (12-fold), sediment flux (285-fold), and trap collection of total number of individuals (95-fold), number of the dominant infaunal organism (84-fold for the bivalve Macomona liliana), and number of species (4-fold). There were very strong, positive relationships among wind condition, water velocity, sediment flux, and postlarval dispersal, especially in the bedload. Local density in the ambient sediment was not a good predictor …

Dispersal Dynamics Of The Bivalve Gemma Gemma In A Patchy Environment, John A. Commito, Carol A. Currier, Laura R. Kane, Kathleen A. Reinsel, Irene M. Ulm

Environmental Studies Faculty Publications

The purpose of this study was to analyze the dispersal dynamics of the ovoviviparous bivalve Gemma gemma (hereafter referred to as Gemma) in an environment disturbed by the pit-digging activities of horseshoe crabs, Limulus polyphemus. Gemma broods its young and has no planktonic larval stage, so all dispersal is the result of juvenile and adult movement. Animal movement was measured using natural crab pits, hand-dug simulated crab pits, and cylindrical bottom traps in the intertidal zone at Tom's Cove, Virginia, USA.

This study demonstrated that horseshoe crabs create localized patches with reduced densities of Gemma, that all sizes and ages …