Lurking in the murky depths of Alberta’s greatest rivers, they are living fossils from a time when giant lizards walked the earth.
But a prominent fisheries biologist fears the province’s lake sturgeon could go the way of the dinosaurs due to increasing pressure on water resources.
“The more you reduce the area where a creature lives, the more likely it is to disappear,” said Lorne Fitch, a retired provincial biologist, university professor and author. “That can certainly happen to lake sturgeon.”
Lake sturgeon are different from other freshwater fish.
Fish survival
They appeared around 200 million years ago and somehow survived the mass extinction of the dinosaurs and the freezing times of the Ice Age.
They haven’t changed much since then — and they look their age.
“They’re monsters,” Fitch said.
Covered with sharp, bony plates and rough skin instead of scales, they can reach lengths of up to two metres.
Long, sensitive “whiskers”, called barbels, grow on the sides of the fish’s mouths, allowing them to find crayfish, snails, clams and leeches in the muddy bottoms of the rivers they frequent.
They have no backbones because they evolved before fish had spines. They live for decades and are difficult to see.
But when they do appear, they look really menacing, Fitch said.
“It’s like pulling the distant past out of a pool. I wondered, ‘What world did these fish evolve into that they had to have these armor plates?'”
Under threat
Once abundant, sturgeon populations are now declining as water quality in Alberta’s rivers has deteriorated and their once-continuous flow has been interrupted by dams.
There are no reliable population estimates, Fitch said, but the western lake sturgeon is listed as a threatened species under the federal Species At Risk Act and as a vulnerable species under Alberta provincial legislation.
“We don’t really know how many sturgeon there are,” Fitch said. “We don’t know what the impact of invasive species is. We don’t know what the impact of drought is.”
He added that both current and possible future policies create problems.
Clear-cutting reduces the watershed’s ability to regulate stream flows. Demand for irrigation continues to grow, while regulators consider thirsty new industries like coal mining.
Meanwhile, Alberta’s population is growing rapidly. That’s driving demand for more freshwater and better flood protection as climate change makes extreme weather more frequent.
New dams that would further isolate sturgeon populations are back on the table, with the province considering projects on the Red Deer and Bow rivers, as well as a dam in southern Saskatchewan.
“We’re not done thinking about dams,” Fitch said. “If these dams are built, lake sturgeon populations will be further restricted to smaller and smaller units.”
A 2002 feasibility study for Meridian Dam, a now-abandoned project originally planned to be built on the western shore of the Saskatchewan-Alberta border on the South Saskatchewan River, found that dams and reservoirs could impact sturgeon.
The study found that such structures can block fish movement, limit food availability and restrict spawning sites.
“The consequences of blocking fish movements in this section of the South Saskatchewan River are significant, as species such as lake sturgeon, walleye and sauger salmon could become isolated from one or more key habitats,” the document reads.
Ryan Fournier of Alberta Environment and Protected Areas said the province is working to improve water storage and management, especially in southern Alberta.
In an email, he said feasibility studies worth about $10 million are underway for the proposed Eyremore Dam on the lower Bow River near Bassano and Ardley Dam east of Red Deer on the Red Deer River. Both dams are located in sturgeon habitat.
“A province-wide review is also underway to identify other areas where new water storage projects would be most beneficial,” he added.
“We are taking a whole-of-government approach to maintaining the province’s water management infrastructure systems to ensure Albertans have a safe and reliable water supply.”
“The ability to survive”
Agriculture and Irrigation Minister RJ Sigurdson said environmental issues would be taken into account in the research.
Alberta should try to reduce water demand rather than rely on more supply — especially as climate change threatens to make the prairies drier and hotter, Fitch said.
“If we continue to tighten the demand side, we will continue to [try to] We will outpace climate change by building reservoirs. And we will lose.”
The sturgeon, which have already been through so much, will thrive if they are given the chance, Fitch said.
“This is a creature that predates the history of humanity, predates the history of many living things. The fact that they still swim in our rivers is a testament to their ability to survive.”
