Burbot fishing at Balfour circa 1960. Photo courtesy of Ron Kerr

COLUMN: The Kootenay Lake fishery and why the kokanee are cranky

How power dams and pollution changed the Kootenay Lake fishery

By Eileen Delehanty Pearkes

First in a two-part series about the Kootenay Lake fishery

If you have any anglers in your life who like to fish for kokanee, you might have noticed they are cranky. No wonder! Two years ago, Ministry of Environment technicians counted only 18,000 kokanee in the lake, the lowest since counts began in 1964, and only one percent of the highest number ever tallied.

That’s right: one percent of kokanee remained in the system. That autumn, ministry technicians planted half-a-million kokanee eggs in the Meadow Creek spawning channel. In spring, 2016, more than 90 percent of those eggs emerged from the gravel beds as fry and entered Kootenay Lake.

After a brief opening, however, the 2016 fishery closed down. The fish had all but disappeared. Rumours surfaced about a mysterious infection. Some anglers blamed overpopulation of a key kokanee predator, the northern pikeminnow. Frustrated locals packed a Balfour meeting in June last year. I was at that meeting and walked out when it was over, thinking about the past. Today’s woes are not the first struggle for kokanee anglers. It’s possible that a closer look at the history can help sort out what needs to happen next.

At one time, Kootenay Lake supported the largest inland fresh-water fishery in the world. The star of the show was the Gerrard Rainbow, an oversized trout maturing at over 10 kilos. Supporting this sport-fishing star were bull trout (once commonly known as Dolly Varden and still called that by many locals); Northern pikeminnow (once known as squawfish); whitefish; sturgeon; burbot and kokanee. People came from all over North America to fish on Kootenay Lake.

They seldom left disappointed.

Many old-timers have shared stories with me about the glory days of the 1950s to 70s, when the fish practically jumped into the boat. It was not hard to catch one’s limit for kokanee in a day. The fish were big, healthy and delicious, especially the burbot. Stories abound of Americans who once brought their own chest freezers with them in RVs, to stock them with burbot before returning to Spokane. It seemed there were enough fish for everyone, and then some.

The healthy fishery in the 50s to 70s is, for many, the gold standard. Ironically enough, it was not entirely natural. During that era, the cold, clean waters of Kootenay Lake received a big charge of nitrogen and phosphorus from industrial pollution discharged into the upper Kootenay River system in Kimberley and Cranbrook. While we don’t tend to see pollution as a positive thing, this effluent made its way 400 kilometers downstream to Kootenay Lake waters.

The “polluting” phosphorus and nitrogen can wreck havoc in warmer waters by causing algae blooms that gobble up oxygen. In a cold, clean water system like Kootenay Lake’s, the nutrients offer habitat rather than taking it away.

As with human beings, when fish have food, they can prosper. And prosper they did. Until the next phase of human intervention caused the opposite: a fish famine.

Duncan Dam, completed in 1967, closed off a natural source of nutrients flowing out of the Duncan River valley. Libby Dam, upstream of Kootenay Lake in Montana, blocked more natural nutrients from entering the lake when it was completed in 1973. Environmental laws ended the discharge of effluent on the upper Kootenay River.

Dams have had a crippling effect on the function of the Kootenay Lake fishery. In my book, A River Captured, I describe how the local wildlife federations and fishermen resisted them in the early 1960s, knowing that they would have a negative impact.

Their protests fell largely on deaf ears in the midst of national political and economic enthusiasm over the Columbia River Treaty. B.C. Hydro easily received water licenses to construct the dams, with only a few small conditions. The government required B.C. Hydro to construct two spawning channels — Meadow Creek on Kootenay Lake, and Hill Creek on Arrow.

Initially, the spawning channel helped. But the millions of fish entering the system found themselves in water that had changed.

Industry no longer pumped phosphorus and nitrogen into the system. Dams blocked most of the remaining natural nutrients from circulating in the system, and decreased oxygen. By the late 1980s, the floor had dropped out of the kokanee population. It was clear that the Kootenay Lake system was on the verge of complete collapse.

Eileen Delehanty Pearkes is author of A River Captured: the Columbia River Treaty and Catastrophic Change.