Submitted to: Book of Abstracts Aquaculture America
Publication Type: Abstract Only
Publication Acceptance Date: 10/15/2006
Publication Date: 2/26/2007
Citation: Edziyie, R., Perschbacher, P.W., Ludwig, G.M. 2007. Phytoplankton succession in sunshine bass fry ponds and the effect of Aquashade® [abstract]. Book of Abstracts Aquaculture America. p. 273. Interpretive Summary:
Technical Abstract: Phytoplankton management in aquaculture ponds is very critical in maintaining good quality water for culturing fish especially during the fry and fingerling stages. Though much is known about succession in catfish ponds, that is not the case for sunshine bass ponds. This study was designed to look at phytoplankton succession in fry ponds and also determine if early or late applications of Aquashade® at the recommended rate of 1 ppm (effectively 2 ppm due to shallow ponds) had any effect on phytoplankton succession. Nine ponds were filled on the 17th of May and stocked with fry on the 22nd of May. Control had no Aquashade®, Early application had Aquashade® put in on the 18th of May, and Late Application on the 12th of June. Each treatment had three replicates. Results indicate that chlorophyll a levels were significantly different between the control and late treatment, but early were not different from either. Control fry ponds were dominated by green algae up to the 27th of May, then the diatoms begun to increase (5/27 – 6/5). Blue green algae (mostly Anabaena spp) started to dominate from the 8th of June until a die off after 19th of June, after which the greens and the diatoms are the two major groups (Fig1). Using a Wilcoxon’s signed rank test from 6/8 to 6/12 (date of late treatment), early treatment Anabaena was lower than late and untreated (Fig. 2). From 6/12 to 6/26, late was lower than control, but not early treatment. But, from 6/14-6/26 late is lower than untreated and early. So it appears to take two days following Aquashade® addition to change the community. Complete control of Anabaena spp (scum forming and off- flavor) might require both an early and a late treatment; however the early treatment seemed to adequately control the Anabaena spp.