. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. FLOW AND SUSPENSION FEEDING 209 i. 9:36 12:00 14:24 16:48 19:12 21:36 0:00 Time Figure 4. Two characterizations of ambient flow regimes at the algal canopy level for Sites 1-3. Sites are denoted by numbers, with arrows pointing to relevant data. Overall mean velocities (OMV) are plotted in the top graph and were calculated from flow measurements in the .v, y. and ; directions over 5-min intervals during inflow (from 1024-1450) and out- flow (from 1513-2311) at Sites 1-3 (see Fig. I). Bars represent one standard deviation
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. FLOW AND SUSPENSION FEEDING 209 i. 9:36 12:00 14:24 16:48 19:12 21:36 0:00 Time Figure 4. Two characterizations of ambient flow regimes at the algal canopy level for Sites 1-3. Sites are denoted by numbers, with arrows pointing to relevant data. Overall mean velocities (OMV) are plotted in the top graph and were calculated from flow measurements in the .v, y. and ; directions over 5-min intervals during inflow (from 1024-1450) and out- flow (from 1513-2311) at Sites 1-3 (see Fig. I). Bars represent one standard deviation. Values of turbulent kinetic energy density (TKED) are shown in the lower graph. See Materials and Methods section for details on flow measurements and characterization of the flow regimes. length. There must also, however, be some slight increase in width—even though zooid width on its own did not vary significantly among sites (but see trend towards increasing width with increased flows; Fig. 5b)—since less elongate zooids in sites exposed to faster flows have areas similar to those of zooids in slower flow sites. Although we made no explicit attempt to compare zooid shapes, other than assess- ing zooid elongation, it was apparent that zooids in colonies exposed to the extremely rapid flows at Site 4 were irregular in outline. They were more hexagonal, often with wavering walls, than the normal elongate, fairly rectangular zooid with straight walls (see Fig. 2). This suggests that calcula- tions based on data for maximum length and width may overestimate the zooid areas of colonies under conditions of very rapid flows. Such irregularly shaped zooids may be a character indicative of exposure to flow in M. incm- hranacea. Table I Ranges of mean velucilii'.t nicu\nrcJ in tin1 \. y. and z directions denoted as u. v. ami u mea\ured at Sites 1-1 during inflow and outflow tidal periods Tidal Period Site Mean u (m s ') Mean v (m s~ Mean w (m s ) 1 Inflow 2 3
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
