How bad are aquatic invasive species?

How bad are aquatic invasive species?

Harps | Friday, 3 July 2015

There has been a lot of media lately about aquatic invasive species in Alberta, recently.

One story about goldfish found in stormwater ponds has spread mis-information throughout Canada and the environmental community. Despite media and inexperienced biologist fear mongering, goldfish flushed down the toilet will not survive and be dumped in stormwater ponds to grow to giants. Those fish were dumped straight into the ponds from an aquarium, likely by some ignorant do-gooder. And they will not end the fishery, many lakes and rivers in Alberta have had reproducing populations of goldfish in Alberta that have either died out or integrated with the ecosystem... this includes the famous Bow River, pike lakes in Lethbridge, and trout lakes in the Crowsnest Pass. And despite other thoughts... I have personally seen a natural predator of goldfish and koi, having a happy chinese food feast.
Some things will eat goldfish...

In central Alberta, thousands of Prussian Carp have been found in the irrigation canals and poor condition streams. These carp (also known as pet store feeder fish) have been around for at least a decade and seem to be limited to these marginal waterways. The worst part is that government folks are telling people to kill all that they find, yet they look similar to many native species such as quillback suckers and the cure could be worse than the impact.

In another northern lake, bullhead were found to be successfully reproducing, or at least multiple generations had been released. The pond will be "wiped clean" using what ever means is necessary (poison is likely). I don't know what the bullhead would do in an intact ecosystem such as the nearby lakes and rivers, rather than in a stocked fishing pond. Potentially they could compete, but in small numbers could they compete and sucessfully reproduce in numbers high enough to start a population?
The worst potential (cost-wise and potentially substrate wise) is Quagga and Zebra mussels. They would be able to spread from whatever surface they are growing on, and potentially affect the bed of lakes, filtering out enough material to make the water too clear and shift the ecosystem. But who knows how they would withstand shifting ice or reservoir drawdown?
What are aquatic invasive species?

AIS, are defined by the US National Invasive Species Council as “a species that is non-native to the ecosystem under consideration and whose introduction causes or is likely to cause economic or environmental harm or harm to human health.
In an earlier front page on brook trout, I was on the fence about some local invasive species.
"My opinion flops on the invasive species topic. Some invasives seem to intergrate and are accepted in our ecosystems, yet others are mercilessly persecuted, with millions spent on removal efforts, often at the expense of ecosystems trying to find a balance."
Many AIS , if successful in surviving, reproducing, and colonizing in Alberta's waterbodies, will cause significant hardship, particularly to industry that rely on water-taking, such as irrigation, oil and gas processing, and power production. The AIS will also either fill an empty niche in the existing ecosystem (such as the missing plankton feeding niche in southern man-made reservoirs that was filled by the human introduced lake whitefish), or the AIS will push another species out of a niche because the AIS is a better competitor.
I realize the importance of preventing AIS from entering a system, but once they are here - what are their impacts? There are studies that show that weeds (plant invasive species) do not become established when the receiving ecosystem is health.

Where are the studies to look at potential colonization risks?
Why would we destroy an ecosystem to save the one we are destroying ... from something that may not be a threat?
We should do all we can to prevent unwanted colonizations, but we should also be studying the potential effects.
And what about the invasives that are already here that the government is just ignoring? House sparrows, European starling, crayfish, many spiders, earthworms, etc. 
They are still expanding, even if only by the cover of night...
Crayfish migrating out of a lake at night

I think we have a long way to go to educate the public and manage AIS in Alberta.
But at least we are making progress in identification and prevention of some incoming AIS.

Thinking of fishing invasive rainbow and brook trout.