Opinion: To save the Bow River’s trout, anglers stand to pay the price

It’s not the first time anglers have felt they were in the crosshairs of fisheries biologist Michael Sullivan from Alberta’s Ministry of Environment and Protected Areas. In the mid-1990s, Sullivan led a walleye recovery plan that many anglers felt unfairly singled them out as the cause of the walleye decline. As with most fisheries, there is typically a cumulative effect leading to a population decline, but many felt Sullivan ignored other factors, resulting in some of the most restrictive angling regulations Alberta has ever seen. One of the most controversial parts of his plan was the institution of a limited-entry draw allowing anglers to keep a small number of walleye.

Now Sullivan is leading the charge to bring more restrictive fishing regulations to Alberta’s famed Bow River, and many anglers are predictably watching with a suspicious eye. While rainbow and brown trout are not native to the Bow River drainage, they provide an important fishery in terms of both recreation and economics, with anglers injecting approximately $24.5 million into the local economy each year. Nonetheless, a recent decline in rainbow numbers has Sullivan and his colleagues looking for a solution—and once again, anglers seem to be their primary target.

THE CASE AGAINST ANGLERS

Interestingly, the number of small fish in the system seems to be robust, but populations of larger fish are seeing a dramatic decline. Although whirling disease has been identified in the Bow drainage, and recent floods have undoubtedly harmed fish populations, Sullivan still pins at least 50 per cent of the blame on anglers. “As a rule of thumb, we generally see declines in young fish with habitat or disease issues,” he says. “Big fish loss is almost always a harvest or entrainment [the loss of fish whenever streams, creeks or rivers are diverted for irrigation and other uses] issue.”

There’s no doubt anglers flock to the Bow. According to a 2018 study, the river saw 200,000 hours of angler effort between June and September, with approximately 45,000 fish caught and released between Fish Creek and Carseland. Since biologists estimate there were only 11,000 catchable fish in that stretch of river, they surmise each fish may have been caught and released four or more times during the study period.

While catch-and-release mortality isn’t well documented, there is undoubtedly some. In recent years, water levels in Alberta’s southern streams and rivers have had lower flow levels than normal, leading to warmer water temperatures. There is fairly conclusive evidence that catch-and-release mortality increases dramatically with a rise in water temperature; Sullivan contends it could account for up to 50 per cent of the Bow’s overall mortality.

THE REGULATORY OPTIONS

At this point, it’s not clear what Sullivan has in mind for regulation changes on the Bow, but it could involve seasonal closures and limiting angler numbers. But even Sullivan himself said, “While potentially effective and fast-acting, these are draconian measures with terrible consequences for fishing and the economy.” Other options under consideration are further restrictions on allowable tackle, and perhaps even on fish handling, but those measures are unlikely to do much to halt the rapid decline in trout numbers.

The elephant in the room is, of course, the amount of water being diverted from the Bow River for irrigation. When flow levels are high, the river can sustain the diversion of excess water. But in times of low flow, as we’ve seen in recent years, diversions result in extremely low water levels and dramatically rising temperatures. That in turn has led to temporary angling closures, so perhaps those will also be part of the solution moving forward.

I’m already starting to hear anglers grumbling about what’s coming, concerned that fishing restrictions are being looked upon as the sole means of recovery for the Bow’s rainbows. On the other hand, I appreciate that Sullivan and his team are in a tough spot, wanting to do what’s best for the fishery, but having to serve a very pro-business and pro-agriculture government. Management by economics rarely works well for the environment, however—or for the recreational users of the resource.

Western View is an opinion column, and we invite constructive discussion on the issues raised here.