While it likely will never be known whether Prussian carp entered Alberta waterways intentionally or inadvertently, research is showing their numbers are increasing in specific areas around the province.
The Alberta Conservation Association (ACA) is entering the second year of a three-year study on the distribution of Prussian carp in Alberta waterways and they recently compiled their 2018/19 project summary report, outlining the findings from last year’s surveys. ACA has partnered with both the U of A and Alberta Environment and Parks for the study.
Their research is an expansion of work conducted by Dr. Mark Poesch, from the Fisheries and Aquatic Conservation lab at the University of Alberta.
“We’re working in collaboration with Dr. Mark Poesch from the U of A, who studied the original work. We took that and expanded it across the province,” said Peter Aku, Fisheries program manager for ACA. “There are some sites where we got positive signals for the first time, where there had been no Prussian carp before. Some sites visited last year came back inconclusive or contaminated; so we’re going back to those sites this year.”
For last year's research, Environmental DNA (eDNA) was collected from 83 sites along 13 major watersheds throughout the province, as well as tributaries and irrigation canals.
From this, Prussian carp was detected at 12 sites, genetically confirming the presence of Prussian carp in Red Deer, Bow, Oldman, and South Saskatchewan river drainages.
No evidence was found in Athabasca, Battle, Beaver, McLeod, Milk, North Saskatchewan, Peace, Pembina, or Smoky rivers.
The objectives of the three-year project are to determine the distribution of the Prussian carp, population demographics, habitat characteristics, and the potential to impact native species.
Brendan Ganton, senior biologist and project lead for this year's research noted that Prussian carp was first confirmed in Alberta in 2006, although there were reports of the invasive species several years prior to that.
“The first detection was in 2000. That was when they were introduced illegally or inadvertently, but it wasn’t confirmed for a few more years,” said Ganton.
The research from last summer shows that the numbers of Prussian carp are increasing in water systems where they already exist, but they don't yet appear to be spreading to other waterbodies.
“The good news is that while there are more locations, they are always within the same watersheds - the Red Deer, Bow, Oldman, and South Saskatchewan,” said Aku.
Prussian carp is a hardy species with a unique reproductive system, making it difficult, if not impossible to eradicate once it has invaded a waterbody.
“It’s Identified as an invasive species, one that is native to Asia and it has had an impact on water environments in other places,” said Ganton.
Not only can they survive in water where there is very little oxygen, but they will eat almost everything from plants, roots, and algae to bugs and other small fish.
It is the very unique reproductive system of the Prussian carp, however, that makes it very hard to control. It reproduces rapidly and can spawn three times a year. Interestingly, the female will reproduce asexually by stealing the sperm of a related native species. In doing so, and coupled with its hardiness, the Prussian carp can easily overtake native fish species.
“The Prussian carp has a weird reproductive system,” said Aku. “Once they are established, they are very, very difficult to eradicate, so we need to learn to manage them.”
Last year, they used just eDNA samples, but this year they are going to also use a technique called electro-fishing and will conduct their studies when water levels are optimal.
“For both eDNA sampling and electro-fishing, adequate water and clarity of water are required,” said Ganton. “We’re aiming for late June, early July, after the spring runoff, but before the water levels are too low.”
The results will allow researchers to map the current Prussian populations, as well as in developing control measures and educational campaigns.
“We’ll look to where and how fast they’re expanding. It also allows us to make decisions for control,” said Ganton.
According to the research conducted by Dr. Poesch, Prussian Carp is one of the most noxious non-native species in North America.
Anglers can do their part in reducing the numbers by killing a Prussian carp if they catch one while out fishing.
Through its “Don't Let it Loose” campaign, Alberta Environment reminds people that releasing live fish into Alberta waterbodies is illegal and has some tips for those who raise fish and for anglers:
Water gardeners, pond and aquarium owners have a number of responsibilities, including:
•taking good care of the species that they keep
•ensuring their artificial water environment stays isolated from the outside environment
•when necessary, disposing of the fish or plants from that environment in a safe and humane manner
Do not dispose of plants and fish from aquariums and ponds into an Alberta stream, lake or river system. Releasing them disrupts the natural balance of Alberta's ecosystems, and ultimately results in biodiversity loss.
For example, koi and goldfish released from ponds and aquariums can survive Alberta's climate and grow to be very large.They have no natural predators in Alberta and will out-compete native species for resources.
It is illegal to release live fish into Alberta's lakes or rivers. Fines can be up to $100,000.
If you are no longer able to care for a fish from your pond or aquarium, do not release it into a lake or river. Try:
•Contacting the retailer for advice, or for a possible return
•Giving it to another aquarium or pond owner
•Donating it to a local aquarium society or school
•Talking to a veterinarian about humane disposal
Do not transfer live fish from one water body to another.
•It is illegal to move live fish from one water body to another. Doing so disrupts the local ecosystem, threatens the existing fish population and, if a stocked fishery, jeopardizes the future of that fishery.
•Fish that are illegally released into a stocked fishery can undermine efforts to maintain that fishery for the enjoyment of all Alberta anglers.
•Once an illegal introduction has occurred in a stocked fishery, the efforts to restore it are extremely expensive and can bring some harm to other parts of the local ecosystem.
•Penalties for illegally transferring fish into any water body aside from the one it was caught in can be up to $100,000 and/or a year in prison.
•Fish introduced from outside of Canada can cause significant damage to local fish populations.Though not currently found within Canadian waters, the silver and bighead carp are threatening to find their way to the Great Lakes. These fish, introduced into US waters from Taiwan, are voracious eaters and out-compete native trout and salmon. These carp are also known for their capacity to leap out of the water, creating a hazard for water skiers and boaters.
•To prevent the introduction of invasive worm species put unused bait back in its original packaging and put it in a garbage container.
•Do you wear waders when you fish? Felt-soled waders are highly absorbent and, if not properly cleaned, can transfer invasive species from one water body to another. Soak them in hot water for at least 40 minutes after every use, or better yet, switch to non-felt-soled waders.
For more information or to report invasive species such as Prussian Carp call 1-855-336-2628.