Invasive Goldfish Management

Once released into the wild, goldfish form large populations and present risks to native species and habitat, including:

• competition with native species for habitat and resources
• increased turbidity, which reduces oxygen in the water and contributes to algae blooms, impacting food resources and killing aquatic wildlife
• Viruses and diseases contracted in aquariums can be passed to other fish if released into the wild 

Aquatic invasive species are spread by intentional release, dumping aquariums or by accidental transfer on boats or equipment. There are some steps we can take to protect our waterbodies from invasive species:

• Never release your plants and animals into the wild or dump aquariums or water garden debris into rivers, streams, lakes or storm ponds or sewers.
• Unwanted pet fish can be disposed of humanely by returning them to pet stores or by giving them away.
• Dead fish can be disposed of by putting it in a bag and then putting it in the garbage.
• Unwanted aquarium water can be poured over dry land, away from waterbodies, and aquatic plants can be frozen and then thrown into the garbage.

While in an aquarium, goldfish tend to grow to about 1 – 2 inches long, when released into the wild, they typically range from 5 – 10 inches with some growing to 15 inches in length!

Female goldfish lay a few hundred to a few thousand eggs at once, which take only 2 to 7 days to hatch.

Goldfish are the longest-lived freshwater aquarium fish able to survive 30 – 40 years. Their long lifespans create plenty of opportunities for breeding and range expansion. An average lifespan is usually 5 – 15 years.

Goldfish are tolerant to low oxygen conditions and can survive local water temperatures.

Invasive goldfish have been identified in the Brett Drive Storm Pond. The Municipality is required by provincial and federal legislation to remove invasive species (goldfish) from Brett Storm Pond.

To effectively manage invasive goldfish, the Municipality will implement eradication measures.

A chemical application of Rotenone is being applied to the pond in August. Crews will be on-site to monitor and complete this necessary work.

Rotenone is the recommended method by Alberta Environment and Parks for eradicating invasive species and once applied to the waterbody, it does not pose any risks to humans, pets or local wildlife (such as birds, bears, deer etc.). 

Project work is expected to take approximately five weeks to complete. Please follow all posted signage and do not enter closed areas.

Rotenone is the recommended method by Alberta Environment and Parks to manage invasive fish species. It has been used in similar projects across Alberta and is proven to be one of the most effective and safest ways to eliminate aquatic invasive species in a body of water.

As projects like this can be costly, it is important to use an effective method for goldfish management the first time around.

No. A 132 pound person would have to consume more than 150,000 litres (approx. 40,000 gallons) 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 control/eradication does not present a risk of adverse effects to humans, animals or the environment.

Certified applicators of rotenone are required to wear a large and comprehensive amount of personal protective equipment including coveralls, gloves, goggles and a respirator as they are handling concentrated amounts of the compound which increases risk and exposure.

When applied to the waterbody, the product is diluted and is generally applied below the surface of the water, reducing the risk to the surrounding area and individuals.

The Rotenone treatment affects fish or species with gills, such as some stages of amphibians and some aquatic insects. Once applied to the waterbody, it does not present a risk of adverse effect to humans, animals or the environment. This is because all humans and animals have natural enzymes in the digestive tract that neutralize rotenone, whereas gill-breathing species do not possess these enzymes and cannot neutralize the compound.

The Rotenone applied to the water will naturally break down over a period expanding from a few days to a couple of weeks, depending on water condition and temperature.

Birds and mammals that eat dead fish and drink treated water will not be affected, for reasons mentioned above. A bird weighing approximately 113 grams would have to consume 95 litres of treated water or more than 18 kilograms of fish and invertebrates within a 24 hour period to receive a lethal dose. This same bird would normally consume 6 millilitres of water and 9 grams of food daily.

Wells and groundwater will not be affected by the rotenone treatment. Monitoring studies show that groundwater in adjacent areas have not been affected. 

Application of Rotenone may cause a mild odour, which may last up to a few days. Rotenone is not harmful to humans, pets or vegetation, even if the odour is present.

Aquatic invasive species disrupt the ecosystem and threaten native fish populations. 

When it comes to their impact on local ecosystems, invasive species can alter a habitat so drastically that it becomes uninhabitable for native populations in local waterbodies.

Aquatic invasive species are spread by intentional release, dumping aquariums or by transfer on boats or equipment.

Never release your plants and animals into the wild or dump aquariums or water garden debris into rivers, streams, lakes, storm ponds or storm sewers. Common aquarium and pond plants and animals can become invasive when released into the wild, potentially causing ecological harm.

It is illegal to transfer fish between waterbodies and could result in fines or jail time.

Pour unwanted aquarium water over dry land and freeze aquarium plants before throwing them in the garbage. Unwanted pets can be disposed of humanely by returning them to pet stores, donating them to schools or community organizations or by giving them away.

No. You can get rid of your dead pet fish by putting it in a bag and then putting it in the garbage. Dead fish are acceptable in your waste bins and will be collected on your collection days.