|MEINELT, THOMAS - LEIBNIZ INSTITUTE OF FRESHWATER ECOLOGY AND INLAND FISHERIES|
|LIU, DIBO - LEIBNIZ INSTITUTE OF FRESHWATER ECOLOGY AND INLAND FISHERIES|
|Straus, David - Dave|
|PETRA, BARTSCHAT - STATE AGENCY FOR THE ENVIRONMENT|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 1/1/2020
Publication Date: 1/15/2020
Citation: Meinelt, T., Liu, D., Straus, D.L., Petra, B. 2020. Fischtoxizität von Peressigsäure(produkten) - Einfluss von Fischart & chemisch-physikalischen Wasserparametern [abstract]. Training conference for fish keeping and fish farming in Starnberg, Germany. January 15, 2020. p. 25.
Technical Abstract: Peracetic acid (PAA; also called peroxyacetic acid) is a stabilized mixture of acetic acid, hydrogen peroxide and water that does not leave dangerous residues in the environment when it breaks down as most compounds do. This study determined the acute toxicity of PAA to 12 fish species in well water. Experiments were designed to provide the 24 h LC50 (median lethal concentration), LOEC (lowest observed effect concentration) and NOEC (no observed effect concentration) values for each species at approximately 23 deg C. Ten fish were placed in static aquaria containing 10 L of well water. Each experiment consisted of 6 PAA concentrations and an untreated control (n=3). Water chemistry for the well water was: pH = 7.5, total alkalinity = 200 mg/L, total hardness = 125 mg/L. The mean LC50 value for all species tested was 5.3 mg/L PAA with the range of 2.8 mg/L to 9.3 mg/L. Black fathead minnows and blue tilapia were most and least sensitive, respectively. The mean NOEC value for all species tested was 3.7 mg/L PAA with the range of 1.9 mg/L to 5.8 mg/L. The immediate impact of this research is to understand the toxicity variance among species and ultimately to determine safe and effective therapeutic treatments. One way to produce sterile fish is through the creation of triploids. Triploidy can be induced through temperature shock applied to the embryo shortly after fertilization; so far, there has been only limited success. We chose a range of temperatures and times post-fertilization to shock the eggs during initial trials. Larvae produced were then checked for triploidy using a flow cytometer. Based on these data, we chose the highest triploid rates from the cold- and warm-shocks to continue trials. A large-scale trial was performed and larvae from both treatments and a diploid control were spawned from a single batch of eggs. Fish will be grown for two years to examine growth and gross morphology. From this large-scale trial, flow-cytometer results on 2-day old larvae indicated triploid production was 54% in the warm- and 52% in the cold-shock treatment groups. Fish were transferred to a fertilized pond where the larvae ate zooplankton over 28 days and grew to about 2 cm. There were few survivors in the cold-shock pond; none of these were triploid when checked with a Coulter Counter (CC). There were several thousand fish in the warm-shock pond and a sample of 50 fish indicated 14% triploid (by CC). Diploid and warm-shock triploid fish were then moved to separate growout ponds and fed commercial hybrid striped bass diets for 5 months; we then determined 7% success rate (by CC) of the triploid survivors. We will grow these until spring spawning 2020 to verify maturation/gamete production vs diploid fish from the same batch of eggs.