piscicides toxicants and explosives n.
Skip this Video
Loading SlideShow in 5 Seconds..
Piscicides, Toxicants, and Explosives PowerPoint Presentation
Download Presentation
Piscicides, Toxicants, and Explosives

Loading in 2 Seconds...

play fullscreen
1 / 20

Piscicides, Toxicants, and Explosives - PowerPoint PPT Presentation

  • Uploaded on

Piscicides, Toxicants, and Explosives. Reasons for using toxicants:. Control undesirable fish in favor of sport species; e.g. suckers or carp Eradicate exotic species; e.g., snakehead Eradicate competitors Control fish diseases Restoration of endangered species. Toxicants for fish sampling

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

PowerPoint Slideshow about 'Piscicides, Toxicants, and Explosives' - esmerelda

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
reasons for using toxicants
Reasons for using toxicants:
  • Control undesirable fish in favor of sport species; e.g. suckers or carp
  • Eradicate exotic species; e.g., snakehead
  • Eradicate competitors
  • Control fish diseases
  • Restoration of endangered species

Toxicants for fish sampling

  • Piscicides: fish poisons
  • Only four registered with EPA:
    • Rotenone
    • Antimycin
    • Two lampricides
      • TFM (3-trifluromethyl-4nitrophenol)
      • Bayer 73 (2-aminoethanol salt of 2',5-dichloro-4'-nitrosalicylanilide)
  • Must be applied by a certified pesticide applicator.


  • • Most common; derived from root of derris plant (a legume)
  • • Blocks oxygen uptake across gills -> suffocation
  • • 1 gal/acre-ft = 3 ppm
  • • 2.5-5% liquid
  • • Powder form: difficult to get into suspension; shelf life is limited
  • • Toxic ~10 days at 70-75ºF (longer at colder temperatures)
  • Effectiveness is function of species, size, water temperature, pH, O2, suspended matter
pros and cons of rotenone
Samples entire community

Low selectivity

Works well in shallow areas

Immediate detoxification with potassium permanganate (KMnO4)

Most fish are ‘sacrificed’

Negative public perception

Non-target species: swine, zooplankton, many invertebrates

Drinking water concerns

Potassium permanganate toxicity

Pros and Cons of Rotenone

Cove rotenone sampling-most common in SE U.S.

Administration of rotenone-mixing with prop wash.


Protocol for rotenone cove sampling:

  • determine cove volume
  • set block net (typically 3/8" mesh w/ 1/4" mesh float collar) pre-dawn or previous day
  • apply dilute solution w/pump at net and deep areas first; hand-spray littoral zone
  • Three day pickupand data collection schedule:
    • day 1: species, length, weight
    • day 2: species, length
    • day 3: species

Evaluation of Cove Rotenoning

  • Pro: allows estimation of standing crop (lb/acre or kg/ha)
  • Biases: typically conducted in late summer, so may not get true species composition or true size structure for populations
  • Scuba shows that 75% of total number and 95% of biomass will surface in 3 days
  • Use is declining because of concerns over fish mortality

Stream Rotenoning

  • Primarily in warm water streams
  • Use block nets
  • Determine velocity and make calculations
  • Use potassium permanganate, KMnO4, drip at lower end to detoxify
  • Antibiotic from the fungus Streptomyces
  • Sold as Fintrol
  • Inhibits respiration at cytochrome level
  • Toxicity decreased by high alkalinity, temperature, sunlight
  • Detoxified with potassium permanganate
  • Affects fish selectively: can be used to ‘clean out’ catfish ponds, as it will eliminate cyprinids, catostomids, percids and centrarchids

Sampling with Explosives

  • • Detonating cord (PrimaCord), dynamite
  • • Typically used only when any other technique is difficult to apply
    • – e.g., too much debris, timber, etc., cannot use seines, gill nets, or hoop/trap nets
    • – low conductivity--cannot use electrofishing
    • – remote area limits amount of gear
  • • Safety!! Likely will be quite a few requirements