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Alberta’s native trout species are all at risk

And it’s driven by human activity.

I was searching for some information on the Government of Alberta website recently when I discovered a page on the fish and wildlife section that talked about fish recovery in the province.

Did you know that every trout species native to Alberta is at risk?

According to the page I discovered on native trout recovery, there are three trout species native to the province: Athabasca rainbow trout, bull trout, and westslope cutthroat trout.

All three species are listed as threatened under the province’s Wildlife Act.

Under the federal Species at Risk Act, the trout range from special concern to endangered.

SpeciesProvincialFederal
Athabasca rainbowThreatenedEndangered
Bull: Saskatchewan–NelsonThreatenedThreatened
Bull: Western ArcticThreatenedSpecial concern
Westslope cutthroatThreatenedThreatened

Athabasca rainbow trout

Historically, of the 19 watersheds in their native range within what is now Alberta, population levels of Athabasca rainbow trout varied between moderately abundant and very abundant in 11 of them.

As of 2017, however, all of the watersheds of this species received either low or very low abundance assessment. While some isolated creeks have health populations, such populations just don’t exist across any of the watersheds, let alone all of them.

Their poor status is associated with heavy land use and development, including forestry, oil and gas, agriculture, and urbanization. These human activities change the flow of surface water and groundwater, fragment streams, increase sediment, and destroy riparian cover.

Bull trout

Prior to European settlement, bull trout were present throughout most river basins in what is now Alberta. Today, the bull trout population in 19 watersheds is functionally extirpated, with very few individual fish, if any at all, being found.

Population abundance, distribution, and size structure is listed as poor in 62 watersheds. In fact, there are only 7 watersheds remaining that have well-functioning populations. These watersheds are either protected or remote.

A bull trout recovery plan published last year identified that human-caused sediment is a widespread potential threat in every basin within the bull trout recovery area. Sediment, according to the plan, is often a result of forestry, oil and gas development, and infrastructure development (such as utilities and roadways).

Plus, two of the basins —Red Deer and Oldman—had phosphorous levels as a recovery threat, too, often a result of agricultural activities, such as cultivation and feedlots.

Westslope cutthroat

Like the other two species, this fish was historically widespread throughout what is now Alberta. Populations have declined dramatically in both the number of populations and their distribution throughout the province. Their decline has been driven primarily by habitat degradation, overharvesting, and the introduction of nonnative species.

A 2006 report found that the greatest threats to the populations of this species human activity that manipulates and degrades the environment; although overharvesting and the introduction of nonnative species have also played significant roles.

Specifically, the report highlighted forestry, mining, and hydroelectric development as major contributors to habitat loss, as well as road construction to support extraction industries (such as forestry and mining). These roads have also led to an explosive increase in the number of access points for fishing and other recreational activities (such as off-roading and ATV use).

All three of the above species require water sources that are cold, clean, clear, and connected to survive, and the habitat degradation mentioned above, combined with fishing pressure and nonnative species (which introduce hybridization and competition), are making access to such water networks a challenge.

Read more about recovery programmes here.

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By Kim Siever

Kim Siever is an independent journalist based in Lethbridge, Alberta. He writes daily news stories, focusing on politics and labour.

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