Author
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Ludwig, Gerald |
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Submitted to: Aquaculture Conference Proceedings
Publication Type: Abstract Only Publication Acceptance Date: 7/24/2001 Publication Date: 1/21/2001 Citation: LUDWIG, G.M. POND NUTRIENTS, ZOOPLANKTON, AND SUNSHINE BASS, MORONE CHRYSOPS X M SAXADILIS FINGERLING PRODUCTION.. AQUACULTURE CONFERENCE PROCEEDINGS. 2001. p.390. Interpretive Summary: Technical Abstract: Sunshine bass fingerling production depends upon using fertilizers to produce the right amount and type of zooplankton at the right time. This study determined the effects of four levels of fertilizers (3 ponds/treatment) on water chemistry, zooplankton and fingerling production.e determined. Rice bran and liquid 10-30-0 NPK were used. They were applied twice weekly in progressively smaller doses for six weeks. A total of 473 kg ha-1 of rice bran plus 226 kg ha-1 liquid fertilizer was applied in one treatment. Other treatments received two, three, and four times as much. Four-day-old fry stocked (37,065 fry ha-1) 4 days after ponds were filled. Fry were fed a 50% protein meal at 11.3 kg ha-1 for 20 days starting at one week after stocking and then at 17 kg ha-1 until ponds were harvested at 43-44 days post filling. Aerators were used during the last 5 days. Rotifers, increased in abundance with increasing fertilization and should also have caused higher fingerling survival. However survival rates (8.9% to 51.2%) were inversely related to fertilizer rates. Increased amounts of TAN and decreased dissolved oxygen levels probably caused higher mortality at high fertilizer rates. Increased fertilization rates may only be beneficial during the first few weeks of fingerling culture. |
