Consideration: Warm Water Angling Restrictions on our Trout Streams

Editor’s Note: Weather and water conditions are going to change for short periods this summer and ease impacts temporarily. The following is where we are at and what the long-range weather forecasts (both 2 week and summer synopsis) suggest is to persist through the 2015 summer season. Please keep this in mind through this summer.

As we’ve mentioned in the weekly Alberta Fishing Forecasts, 2015’s spring and early summer weather has led to the best conditions our trout streams have seen in years. We’ve also stated that continued hot weather with little to no precipitation will eventually catch up to us, leading to stress on our trout. We’ve said all along to enjoy fishing the low, clear water conditions until the time comes that there is too little water, too little flow, too much daytime heat to allow water to carry enough oxygen to help trout recover after being caught.

That time has come.

We’re likely staring at the warmest drought since 2002. The warmest, driest spring to early summer in recorded history on the prairies has had impact and it’s time to consider the trout we’re catching. We legitimately have to ask ourselves “Should I be fishing? Is this fair to the trout?” If you’re standing in the hot sun, sweating, and the stream or river water feels warm, it’s a sign you likely shouldn’t be trout fishing.

As water warms, its capacity to hold dissolved oxygen lessens. When waters are as low as they are now, heat from the sun warms the entire stream rapidly. Trout struggle to breathe and heat stress takes further tolls. Further, available trout habitat is reduced significantly, forcing trout into the few holding lies to avoid predation, to find solace and respite, to avoid energy expense. This is all stressful. Optimal trout water temperature is 10 – 15C. At those temperatures the dissolved oxygen levels are prime. Such temperatures are typically married to good stream flows that in turn provide ample holding lies in spread out spring to summer trout population distribution. With daytime temperatures of 25 to 35C recently coupling with overnight temperatures of 14 to 18C, many of our streams are 20C or higher through the entire 24 hr period daily at present. It was the cool overnight temperatures that had been keeping our waters cool through early summer. That has changed, especially on waters slightly west of, and all small to mid-sized waters east of hwys 22 south of the Yellowhead and Hwy 40 north of the Yellowhead.

During warm spells (warm to hot days or continued warm nights) CONSIDER :

  • Limit fishing to midnight through 2pm. Avoid 2 in the afternoon through midnight as those are the warmest, most stressful periods of the day.
  • Fish riffled waters
  • Fish tailwaters, spring creeks, lake outflows, or heavily treed waters.
  • The best fish handling possible.
  • Use heavier leader to play fish quickly.
  • Limit fish photography/videography.

The long-range forecast is for continued heat and drought. It’s unfortunate that we’re experiencing such a dramatic drought and heat wave so soon after the 2013 floods but do keep in mind trout do have resiliency. If we do our part to avoid adding stress, trout will lie doggo, expending little energy as they side up to logs, behind and under rocks or rock ledges, nose into riffles, etc to avoid energy expense until conditions change. Even if we do experience some summer kills (and we aren’t there yet), remember that nothing is ever absolute nor permanent, that just as we’re seeing an incredible return of some of the chunkiest rainbow trout on record in the Bow River after the 2013 flood, our drought-stricken waters will recover (if they are indeed impacted).

Belly River DroughtWe fished southern Alberta last weekend and it’s incredible to see the lower Belly (above photo), Waterton (below photo), and St Mary Rivers so low. The St Mary R tailwater mid afternoon temperature was nearly 25C last weekend 3km below the dam. Each afternoon recently there is a serious algae release from the river bed, turning the river creamy white with massive chunks of released algae (which further inhibits available dissolved oxygen for trout). The river release from the dam was 4 m3sec while we visited, though there were 71 m3sec in the irrigation canal, which is flowing cold, clear, and clean. With these conditions we cut our trip short by two days as the fish were extremely lethargic and sluggish during the day. We fished 2 evenings and one morning before pulling the pin on that trip. It simply isn’t ethical to fish these waters at present.

Waterton River drought

Central Alberta brown trout streams are equally low. Prairie Creek has been as low as you’ll likely see it in your lifetime. The browns are easy to spot as they cruise stagnant water or slide in to rest amongst logs and rocks. The Dogpound’s browns are sluggish. Fallentimber is like a bath. The Little Red Deer is perfect for a swim. The Red Deer R in Red Deer is prime temperature and flow for the hundreds of dingies floating from the Penhold bridge and Fort Normandeau daily. There are many other waters that are simply too low, too warm.

While high country cutthroat trout waters are presently cooler, they aren’t too far behind in concern. Their saving grace is the cool overnight temperatures of our foothills and mountains at present. The caution is that these native and high country trout have lower temperature tolerances than lower elevation rainbows and browns. Cutthroat and bull trout start to stress once water temperatures warm into the mid to high teens C.

Our northern waters are certainly not exempt. Our northern bull trout and grayling waters are soon to feel the heat as well. For the second consecutive summer the weather is drier and hotter north of hwy 16 than south. Concentrations of fish will be found earlier in the summer, pooling them into close proximity.

This is a tough summer on trout. Please consider stopping fishing by 2 pm on days where the air temperature is +24C or more. While that might sound low to not fish, the lingering impact of warm daytime heating and warm over night temperatures are keeping our trout waters warm through the entire 24 hr period. A general guideline: If you are hot in the sun and warm in the water please consider the trout you are fishing for are teetering on being unable to recover from you catching them. While most of us practise catch and release, it’s simply unethical to do so knowing that they are likely to struggle immensely once released.

Fish Handling – If you are going to fish, and many people will, imagine yourself sprinting full-out for a full minute. We’d all be breathing hard and heavy. Now take away 60% of the available oxygen. Feel like passing out? Stressed? That’s what we have to consider on warm trout waters. Focus your fishing in riffled waters. This is a benefit on two fronts: the active fish will most likely be found in riffles. More importantly, once you land the fish in the shallow edge water (which will be warm and poorly oxygenated) you can quickly release it into the main flow, oxygen-rich, riffled water. Use 8+lb leader or tippet to bring fish in quickly. You are encouraged to touch the trout as little as possible to avoid additional stress. Try to not remove trout from the water, leaving its gills submerged at all times. Try to slide your hand down the leader to remove the hook without touching the fish. Be sure to limit your photography – keep the fish wet, hold it as little as possible, and simply let it slide back into riffled water. Do your best to fish at the coolest time of the day, late night or first light.

The most susceptible waters: Lower elevation and the further east waters are always more susceptible as they tend to be slower flow, prone to solar radiation. Southern waters such as the Waterton, St Mary, Belly are like this, especially so since they flow through grasslands. Slow flowing brown trout streams of central Alberta are extremely low and warm. Smaller waters see impacts of warming earlier in the day – they also cool sooner in the late evening.

The best opportunities: Larger rivers usually offer better mixing of oxygen and can be fished longer into the day and season. Large rivers have long riffles that mix in oxygen and the volume of water takes longer to heat each day. The rub is that larger volumes of water take longer to cool and once heated can take several days to cool. Further opportunities to fish exist on streams with tighter treed canopies that block the sun and heat; spring creeks that have constant flow and temperature; lake outflows; tailwaters (dam releases) are mostly bottom releases in Alberta and are quite cool. This typically provides cool water to fish at this time of the year as the reservoirs haven’t warmed fully. While smaller tailwaters may warm during the day the cool water flush can re-invigorate the river as cool water flushes the warmer from the dam-downstream each evening and through the night.

Night Time Fishing

In the following video –  we are at the place of fish struggling to find oxygen, to find a comfort zone. We are well into drought and the heat is having impact. Fast forward to 3:55 of this video and that’s exactly where we are. (PLEASE NOTE: drought similarly impacts all trout, not just brown trout).

One final word: while this awareness article is shared at a time of drought and heat, the same considerations need to made at all times of the year on a stream by stream specific consideration. Please always keep a considerate mind to the plight of our trout in our ever-changing conditions.

Dave Jensen
Alberta Fishing Guide Magazine

3 thoughts on “Consideration: Warm Water Angling Restrictions on our Trout Streams

Leave a Reply