Low Water Fishing

[waskeyc]

I've seen in numerous places recently references to a lack of fishing success when the water in a river or stream gets low at this time of year. I understand that low water warms faster, and that can be dangerous for coldwater species, making fishing for them inadvisable. But what about if the water temps are OK? And what about if the fish aren't sensitive to warm water, such as bass and sunfish? Here's my bigger question: Since there is less water in the stream, but the same number of fish, wouldn't that make the fishing easier? The fish are easier to find, the food is more scarce, and the fish's metabolism would be higher in warmer conditions, right?

I suspect the answer may depend somewhat on region, as different combinations of low water / warm temperature exist in different parts of the country right now. In my area of the country, the small mountain trout streams are low, but the water temps are pretty good as our summer temperatures have been very near normal with no extremely hot periods (yet). I was at a stream last weekend and the flow was just a trickle, but the water temp was in the mid 60s even at a low elevation. In my backyard warmwater stream, the flow is just a fraction of the annual average, but the water temperature is only in the mid 70s. I would expect to find concentrated, hungry fish in both environments, leading to good fishing.

Are we mistakenly associating dangerously warm water with low water levels when we say that low water hurts fishing opportunities, or am I missing something? What do you think?

[sagefisher]

waskeyc,

For trout, low waters combine two negative conditions: Higher water temperatures (70+ is bad for trout) and low oxygen levels. So even if the water manages to stay below 70 degrees, the oxygen levels may be way too low to sustain the fish. That can also hold true to warm water species, they need the oxygen levels to be high enough to sustain life.

It is true that the fish will be more concentrated when levels are low, hence another aspect comes into play, food levels. The 90% to 95% time that fish are feeding under the surface means that those bugs have to be around to be eaten. When stream/river levels get too low, many of the bugs burrow deeper into the rocks to stay in the water, so they are not around to be eaten by the fish.

But, life will sustain itself, one way or another. Many fish will head downstream to better waters and return to their own waters when water levels increase. Some fish get stuck in deep pools and are very easy targets for predators, both human and natural enemies.

In the early 2000's, Montana was going through a 5 year drought. I drove over there for some river fishing and the guide to me to the Beaverhead, the upper portion a little ways below the dam. We walked in to the river and there it was, the famous Beaverhead River. Actually, it was no longer a river but rather a 3 inch deep small stream that flowed into pockets of water. You know the old saying about shooting fish in a barrel, well that is what it would be like fishing there. I told the guide that that was not my style and told him to take me to a place where there was actually a river that had some water in it. So we fished the Jefferson, below the confluence of the Beaverhead and Big Hole.

If you fish those low water streams, get the fish in as fast as you can without hurting them and release them ASAP. Take some time between catches to sit and watch the water and enjoy nature.

Have fun,

Larry ---sagefisher---

[ScottP]

It's been so hot, dry and smokey up here in NW MT I haven't even thought about fishing any of the local streams, even those that aren't under Hoot Owl restrictions.

Regards,
Scott

[redietz]

Since there is less water in the stream, but the same number of fish, wouldn't that make the fishing easier? The fish are easier to find, the food is more scarce, and the fish's metabolism would be higher in warmer conditions, right?

The chief reason that low water make fishing more difficult is that fish are more skittish in skinny water. They're much more vulnerable to predation from above (mainly in the form of birds) and it takes a lot to convince a fish to leave whatever shelter it's found just to eat. They also can see you from farther off in clear, still water and will take off at the slightest movement on your part.

Temperature doesn't really play into this (of course you should avoid fishing for cold water species when the temperature is too high). On my local tailwater, it's much harder to catch fish at a flow of 30 cfs than it is at a flow of 120 cfs, even though the water temps are same (and never above 60 degrees). It just take one misplaced false cast to scatter (the clearly visible) fish everywhere.

And with lower and slower flows, the fish have more time inspect your offering. There's no "gotta grab it before it gets away" instinct.

And why do believe that food is more scarce? Yes, low flows often occur in late summer after the major hatches gone away, but the lack of aquatic food is compensated for the increased amount of terrestrial food (and bait fish are easier to catch.)