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<br />Water Quality Measurements <br />Water temperature, pH, and dissolved oxygen were monitored over a 24 hour period for <br />multiple days at approximately two week intervals between June 11 and August 6 with a <br /> <br />Hydrolab minisonde. Measurements alternated every other day between each enclosure during <br />the time period. A staff gage was placed at the deepest site in the high-density fish enclosure and <br />checked every few days to monitor maximum depth in the enclosures. Zooplankton was <br />sampled at one-week intervals between May 14 and July 15, 2002. Three samples each were <br />taken from the high-density enclosure, low-density enclosure and outside the enclosures on each <br />sampling date. The plankton net sampled an area of 0.07 m2 and were 80 micron mesh size. <br />Fish stocking and sampling <br />Two densities of razorback sucker and bonytail larvae with approximately equal numbers <br />of nonnative fish were tested (Table 1). The numbers of nonnative fish introduced were based <br /> <br />on densities observed during the Levee Removal study (Birchell et al. 2002). Prior to breaching ~ <br />the levees for the Levee Removal study, the floodplain sites were dry and so the fish populations <br />were reset. The fish assemblage, and relative density, that entered these reset floodplains during <br />the first year of the Levee Removal study was used to test the reset theory in this study. The i <br />high-density enclosure (high for endangered fish larvae) was stocked with 81 fathead minnow <br />(Pimephales promelas), 37 red shiner (Notropis lutrensis), 15 black bullhead (Amierus melas), <br />18 green sunfish (Lepomis cyanellus), and 3 carp (Cyprinus carpio) (154 fish) prior to ~ <br />introducing larval endangered fish. The low-density enclosure (low for endangered fish) <br />received 75 fathead minnow, 42 red shiner, 16 black bullhead, 12 green sunfish and 4 carp (149 <br />fish) also prior to introducing larval razorback (Table 1). The nonnative fish used in the 7 <br />experiment were collected from the Green River and local ponds, and they were of mixed age <br />1 +. <br />1 <br />4 <br />