Submitted to: Book of Abstracts Aquaculture America
Publication Type: Abstract Only
Publication Acceptance Date: 12/10/2008
Publication Date: N/A
Citation: N/A Interpretive Summary:
Technical Abstract: Rooted macrophytes make harvesting fingerling sunshine bass Morone chrysops × M. saxatilis difficult because they tangle in the seines and increase fish stress. Aquashade(c), a dye, is used to reduce macrophyte growth. Fingerling culturists are reluctant to use it because it may reduce phytoplankton concentrations and zooplankton food supplies of larval fish. Aquashade(c) was applied at 4 mg/L (twice the recommended rate) to three ponds when they were filled and to three ponds at the time fry were started on prepared feed. An additional three ponds served as a control. All ponds were stocked with sunshine bass larvae at 15,000/0.04 ha. Water quality and plankton were monitored daily until fingerlings were harvested. Almost no differences were found among treatment ponds for in water quality, chlorophyll a, primary productivity, phytoplankton and zooplankton concentrations or weight of rooted macrophytes. No differences were found in the number, total weight or per cent survival of fingerlings harvested from the ponds. Differences in average individual total length, total weight and coefficient of condition were found but were not thought to be related to dye use. The dye did not reduce fingerling production but it was not effective for rooted macrophyte control.