Aquatic Sciences Meeting, Albuquerque 2001

SS07 Biomechanics: Turbulent Mass Transfer (Environmental Connections)

Date: Monday, February 12, 2001, Time: 3:00:00 PM

Location: San Miguel

Zimmer (previously Butman), C, A, Biol. Dept., UCLA, Los Angeles, CA, USA, cbutman@obee.ucla.edu

Zimmer (previously Zimmer-Faust), R, K, Biol. Dept., UCLA, Los Angeles, CA, USA, z@biology.ucla.edu

Starczak, V, R, Woods Hole Oceanographic Institution, Woods Hole, MA, USA, vstarczak@whoi.edu

LARVAL SWIMMING, TRANSPORT AND SETTLEMENT IN THREE-DIMENSIONAL LABORATORY FLOWS AND THE ROLE OF NEAR-BED FLOCCULATED MATERIAL

Planktonic larvae of the opportunistic polychaete Capitella sp. I select high-organic muds indicative of the adult habitat in steady, one-dimensional flume flows. Such flows are idealizations of nature. Here, larval settlement was quantified in the more complicated, yet predictable and well-described 3D flows that occur in annular flumes. Video observations of individual swimming and exploratory behavior were coupled with settlement rates of the flume larval population, all as a function of flow regime (u* of 0-1.6 cm/s). In experiments with mud cores, settlement rate decreased with increasing flow speed. Negatively buoyant flocculated material ("flocs") was eroded from the cores at high flows, and concentrated along the inner flume wall due to the corkscrew-like circulation in annular flumes. Larvae moved toward and were contained within flocs, and thus, additional experiments were conducted using "flocs only" and "no flocs" treatments. These results explained the decreased settlement at high flow -- 40-90% of the larvae were found in flocs at the inner flume wall, with higher percentages at higher flow speeds, whereas few larvae were found along the inner flume wall in the absence of flocs.

This Session Listing

Aquatic Sciences Meeting, Albuquerque 2001

Quicklinks