All about Rotenone

What actions have been considered to correct the goldfish management problem?

The Town attempted a physical removal method first because of a Canada-wide shortage of certain types of Rotenone. We have considered 3 ways to remove and control invasive species:

• Physical/mechanical
  Unfortunately, these techniques don’t work well. Methods include nets, traps, electrofishing gear, and managing water levels and flows. Many others have tried these methods without success
• Biological
  Biological control is great for long-term management, but not to eradicate fish. Why? Because there is no guarantee that the predator will eliminate the target species and all its life stages, such as eggs. Target species may spread to other waterbodies before the predator can reduce invasive species population. Also, stormwater ponds are not a healthy habitat for predatory fish.
• Chemical
  Chemical control is the only method likely to eliminate undesirable fish in a body of water. The use of Rotenone offers the highest likelihood of success.

Why is Rotenone the most likely alternative management technique to remove goldfish?

• Rotenone provides the highest chance of success
• It can remove Goldfish fast enough so that they don’t spread to other waterbodies.

What is Rotenone?

• Rotenone is a naturally occurring compound made from the roots of a tropical plant of the bean family
• It has successfully eliminated invasive fish
• Alberta Environment and Protected Areas use the commercially available Rotenone formulation called Prentox Nusyn-Noxfish Fish Toxicant. It is a registered pesticide with the federal Pesticide Management Regulatory Agency (PMRA)

Is Rotenone harmful to humans when used as a goldfish management tool?

• No. A 132-pound person would have to consume more than 40,000 gallons (approx. 150,000 litres) of Rotenone-treated water within a 24-hour period to receive a lethal dose
• There is no opportunity for long-term effects since Rotenone biodegrades within two to four weeks
• The use of Rotenone for fish eradication does not present a risk of adverse effects to humans or the environment
• If Rotenone is not considered harmful, why does the pesticide application team wear personal protective equipment, including coveralls, gloves, goggles, and a respirator?
• Certified applicators handle concentrated products, which are have a larger risk of exposure
• When applied, the product is diluted and generally applied below the surface of the water, reducing the risk to the surrounding area and individuals

How long will the Rotenone treatment take?

• Project planning has lasted for months, but the Rotenone application takes a day
• Signage, barricades, and fencing will be installed before the application, and stay up for two weeks after the application

Does Rotenone affect all aquatic animals the same?

• No. Fish are more susceptible
• Gill-breathing animals such as fish, some amphibians, and some aquatic invertebrates are more susceptible to Rotenone. Their digestive enzymes cannot neutralize Rotenone
• Some organisms, like aquatic insects, are susceptible to Rotenone. But studies have shown that these organisms can quickly repopulate after treatment

Will wildlife that eat dead fish and drink treated water be affected?

• No. Birds and mammals that eat dead fish and drink treated water will not be affected. Their digestive system neutralizes the Rotenone
• A bird weighing 0.25 pounds would have to consume 100 quarts (95 litres) of treated water or more than 40 pounds of fish and invertebrates within a 24-hour period to receive a lethal dose. This same bird would normally consume 0.2 ounces (6ml) of water and 0.32 ounces (9g) of food daily

What can you expect during the proposed Rotenone treatment?

• Residents may notice:
• Fencing and barricades placed around the pond
• Chemical odours for 1 to 2 days
• Temporary change in watercolour
• Appearance of dead fish for 1 to 2 weeks
• Town staff monitoring the pond and surrounding area for 1 to 4 weeks

Questions

• Leave your questions in the project Ask & Answered