Control of Potentially Toxic Cyanobacteria Using Chemicals 2017

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  • Control of Potentially Toxic Cyanobacteria Using Chemicals or

    Fish

    Gary J. Burtle

    University of Georgia

    Animal & Dairy Science - Tifton

  • Unusual Number of Toxic Blooms

    Toxic Algae blooms in Georgia causing cattle deaths

    Blame placed on drought conditions

    Rains in early 2012 followed by drought lead to concentration of nutrients in pond water

    Reduced pond flushing

  • Cattle Deaths

    More than two dozen ponds with reported cattle problems

    Six cases of cattle deaths

    2 to 8 cattle deaths per case

    Aborted or still birth calves in surviving cows

    Others with avoidance of pond water or dense algal blooms

  • Main Algae Suspects

    Microcystis

    Cylindrospermopsis Euglena sanguinea

    Euglena

  • Some Algae Toxins

    Algae Toxins

    MicrocystisAnabaenaPlanktothrix (Oscillatoria)AphanozomenonNostoc

    Microcystins (liver)Anatoxin-a (nerve)

    Cylindrospermopsis raciborski Cylindrospermopsin (liver, kidney)Saxitoxin (nerve)

    Euglena sanguinea Euglenophycin* (neurological)

    Lyngbya Lyngbyatoxin-a (skin)Aplysiatoxins (skin, gastro-intestinal)

    Toxic Cyanobacteria in Water: A guide to their public health consequences, monitoring and management. Edited by Ingrid Chorus and Jamie Bartram, World Health Organization, 1999.*Identification of euglenophycin--a toxin found in certain euglenoids. Zimba PV, Moeller PD, Beauchesne K, Lane HE, Triemer RE. Toxicon. 55(1):100-4. 2010.

    http://www.ncbi.nlm.nih.gov/pubmed?term=Zimba PV[Author]&cauthor=true&cauthor_uid=19615398http://www.ncbi.nlm.nih.gov/pubmed?term=Moeller PD[Author]&cauthor=true&cauthor_uid=19615398http://www.ncbi.nlm.nih.gov/pubmed?term=Beauchesne K[Author]&cauthor=true&cauthor_uid=19615398http://www.ncbi.nlm.nih.gov/pubmed?term=Lane HE[Author]&cauthor=true&cauthor_uid=19615398http://www.ncbi.nlm.nih.gov/pubmed?term=Triemer RE[Author]&cauthor=true&cauthor_uid=19615398http://www.ncbi.nlm.nih.gov/pubmed/19615398

  • Fate of toxins in the Environment

    It appears likely that cyanotoxins are produced and contained within the actively growing cyanobacterial cells. Release to the surrounding water, to form dissolved toxin, appears to occur mostly, if not exclusively, during cell senescence, death and lysis, rather than by continuous excretion. Kaarina Sivonen and Gary Jones, WHO 1999.

  • Tifton Studies on Algae Control

    Planktivorous fish

    Threadfin shad (600 per acre)

    (Or, stock 100/A and encourage spawning)

    Algicides

    Copper sulfate

    plus sodium percarbonate

    Cutrine plus

  • How to Improve Results of Sodium Percarbonate Application

    Increase rate of applicationfrom 8 lb to 25 lb/A

    OR, use in combination with COPPER

    0.1 to 0.25 ppm as copper sulfate

    Apply early in the day,

    before full sun or late in the day,

    after full sun

  • Treatment Evaluated

    0.25 ppm Copper Sulfate crystals (0.675 lb per acre ft of pond water)

    Dissolve in warm water before distribution

    25 lb GreenClean per acre ft of water

    Broadcast over the pond area as evenly as possible

    Applied before 10:00 AM

  • Changes to Phytoplankton after Treatment0.25 ppm Copper Sulfate plus 25 lb/Acre Sodium Percarbonate

    Time Microcystis Aphanocapsa Rhabdoderma Scenedesmus

    Initial 1,544 33,977 6,037 1,895

    24 hr. Post

    Treat

    210 22,324 1,334 2,257

    48 hr. Post

    Treat

    929 14,531 772 7,582

    72 hr. Post

    Treat

    421 12,987 351 7,722

    Pond 18 Moderate Bloom

    Colony units per milliliter, average of 4 samples.

  • Changes to Phytoplankton after Treatment0.25 ppm Copper Sulfate plus 25 lb/Acre Sodium Percarbonate

    Time Microcystis Aphanizomeno

    n

    Rhabdoderma Scenedesmus

    Initial 53,212 2,808 842 9,547

    24 hr. Post Treat 54,194 1,544 ND 6,318

    48 hr. Post Treat 35,942 421 982 9,126

    72 hr. Post Treat 45,541 421 421 9,574

    Pond 22 Dense Bloom

    Colony units per milliliter, average of 4 samples.

  • General Observations

    Algicide treatment can be selective

    Apply before dense scums appear

    Reapplication will probably be necessary, but perhaps only with Sodium Percarbonate

    Cost of chemical per acre ft: about $51.00

  • Implications

    Begin control before dense blooms develop.

    Pond owner should adopt long range plan for phytoplankton management including drought conditions.

    Repeat application

    1 to 2 weeks apart

    Test for toxin

    County Office

    About $100