Submitted to: The 1890 Association of Research Directors Biennial Research Symposium
Publication Type: Abstract only
Publication Acceptance Date: 5/16/2008
Publication Date: 6/8/2008
Citation: Perschbacher, P.W., Ludwig, G.M. 2008. Risk evaluation of drift from 40 aerially-applied herbicides on fish production pond plankton and water quality [abstract]. The 1890 Association of Research Directors Biennial Research Symposium. p.36. Interpretive Summary:
Technical Abstract: Row crop herbicides were tested for possible adverse effects on pond plankton and water quality in triplicate 500-L outdoor, pool mesocosms. Treatments were drift at low (1% of full field rates) and high levels (10% of the full rate) to production ponds of 5 ha and large, and no drift (control). Herbicide (without additives) was sprayed on the pool surface and evaluations repeated at 24 and 48 h post-application, and if effects were noted continued until morning oxygen levels did not differ from controls (i.e. recovery). Of the 40 herbvicides tested, only diuron affected phytoplankton and oxygen production in relation to dose. However, morning oxygen levels fell to critical levels of 3ppm and below after one week in the high drift treatment. Zooplankton was also reduced relative to control levels at both drift levels. Positive impacts noted from diuron high drift were reduced bluegreen algae and reduced unionized ammonia. Two additional herbicides, atrazine and carfentrazone primarily affected zooplankton.