Fly fishing while trout are spawning isn’t inherently wrong, evil, or immoral. In many ways, fishing the spawn is one of the more effective tools anglers can use to better manage out-of-control trout populations.
Before calling for my head on a stick, allow me to explain.
Catch-and-Release Works Almost Too Well
Catch-and-release fishing has been so effective in the past 30 years (probably longer, but at least since the River Runs Through It surge in the sport in the 90s) that a fair number of trout streams are now overpopulated. Streams with brown trout, in particular, seem to be the hardest hit.
This isn’t an anecdotal claim, either. Phaedra Budy and Jereme W. Gaeta, two wildlife researchers, wrote a paper for Utah State University about the invasive nature of brown trout, and the problems brown trout pose to certain fisheries.
The whole study is worth reading, but one fact proves essential for the discussion on fishing to spawning trout, especially browns.
In Utah’s Logan River – a freestone stream managed as a wild trout fishery, and one of the few remaining dam-free rivers in the West – brown trout occur at a rate of nearly two fish per square meter of water. In their native range in Europe, brown trout typically occur at a rate of 0.4 fish per square meter.
For the Logan River, that means its brown trout exist at a density almost 1.5 times greater than the density to which they evolved.
That story is played out on hundreds, if not thousands, of other rivers here in America, and it’s the density that proves more of an issue than anything else. As noted in this paper in the journal Evolutionary Ecology, freshwater fish (such as trout) populations will stunt when too many fish exist in a given waterbody. I bet most anglers can name a few streams off the top of their heads where the brown trout have overpopulated, with almost no fish exceeding eight-to-ten inches in length.
To fix this problem of stunted fish, we generally have two options: remove excess fish from the waterbody (often through a rotenone treatment) or introduce a highly-piscivorous predator. Both options have their merits.
Poisoning a waterbody is usually a fishery manager’s last resort. It’s often more palatable to the public – and far cheaper – to introduce a predator species than it is to kill off an entire fishery. And in rivers where brown trout are the only gamefish, poisoning the river means losing the fishery entirely for at least a year.
The next logical question, then, is what predatory fish can we introduce into stunted brown trout populations that won’t further unbalance that waterbody’s ecosystem?
Sterile predators like tiger trout are often a popular choice, especially here in the Rocky Mountains. They can’t reproduce, which means fisheries managers can stock an exact number of predator fish in a system. The risk of the new fish wiping out an existing brown trout population in its entirety is extremely low, so anglers shouldn’t worry they’re trading one overpopulated fish for another.
What About Harvest?
The other option to deal with stunted fish populations is increasing harvest. As noted earlier, though, harvesting trout is a hard sell for most fly anglers. Catch-and-release is so engrained into our collective psyche that the idea of keeping a full limit of fish feels almost wrong.
In some fisheries, it is wrong. Wild, high-country cutthroat streams, for example, likely need no harvest. Famous tailwaters like the Green River below Flaming Gorge, or the Frying Pan River below Reudi Reservoir, don’t need large-scale fish harvests. Both the Green and Frying Pan might see a bump in average trout size if a few were removed each year from the river, but with both fisheries providing such incredible trophy-class opportunities, it’s best not to mess with a good thing.
On rivers where trout are notably struggling, harvest isn’t a viable option. The brown trout in Montana’s Big Hole River, for example, are currently in a precarious spot. And even though larger browns are fewer and further between than they used to be on the Big Hole, harvest isn’t going to improve that problem.
Should We Fish During The Spawn?
I say all this to counter the dozens, if not hundreds, of self-righteous social media posts I see from anglers every autumn. You’ve seen them, too. Anglers condemning others for fishing during the brown trout spawn, for “raping redds” and “stomping all over the future’s fish.”
To those anglers, I ask: Is fishing during the spawn really a bad thing? In light of the information put together here, if someone chooses to fish during the spawn on a stream that’s overpopulated with brown trout, is that somehow a morally wrong or evil choice? If we’re not going to harvest enough trout, and introducing predators isn’t an option, then what other option do we have to reduce populations back to a sustainable level? Or does our fishing during the spawn even make a noticeable difference?
To those same anglers: Is it wrong that we hunt elk during the rut, or other big game animals when they’re nearing mating season? That’s been the American model of hunting for decades, and we have the best public land hunting in the world. What’s the difference between shooting a bull elk out of a herd of cows, or catching a big brown trout from behind a redd?
There’s no difference.
Unless you’re fishing to trout that are actively spawning on a redd, there’s no difference between that and hunting elk during the rut. I’ll go out on a limb here and assert that most of us who hunt wouldn’t likely shoot an elk right in the middle of it propagating the species. By that same token, we shouldn’t pull fish that are actively spawning off redds.
The fish behind the redds, or to the side, however, are fair game. Especially in rivers where the population needs harvest to stay in balance.
You shouldn’t walk through redds. If you’re lucky enough to stumble on a massive fish on a redd, sit back and watch instead of casting. The behavior of these fish during spawning season, especially browns, is fascinating.
We absolutely need to care for and cherish our fisheries. Every angler has to be on board with conservation and preservation; otherwise, we’ll quickly lose what few fisheries we have. Part of that, however, is understanding that harvest is a necessary conservation tool. Some rivers – especially those with stunted trout populations – need the extra harvest when the fish are at their most vulnerable. We have to exercise discretion, stay within the regulations set by local fisheries managers, and use a bit of common sense. Some fish should never be bothered during spawning season, like cutthroat, bull, and golden trout. But I reckon most anglers are smart enough to decide for themselves if they’re fishing somewhere that can adequately handle the increased pressure during the spawn.
I’ll end with this. If the hordes of people fishing Utah’s Lower and Middle Provo Rivers (two of the busiest rivers in the state) during the spawn haven’t put a dent in brown trout numbers, then I’m not sure anything will.
So quit jumping to judgement, especially on social media. Celebrate what others catch. Facilitate the community that fly fishing is so well-known for. Remember that fishing during the spawn isn’t always wrong.
Spencer Durrant is a fly fishing writer, guide, and bamboo rod builder from Utah. He runs the Utah Fly Fishing Company, is the News Editor for MidCurrent, and a regular columnist for Hatch Magazine. Connect with Spencer on Instagram/Twitter, @Spencer_Durrant.