Why Do Trout and Salmon Jump? But Then Refuse to Bite?

Have you ever been to the river and seen trout jumping, and wonder what they might be up to? Well in this article, I hope to share the main reasons why trout jump high into the air.

I will also share tips, on how to catch trout that are jumping.

Why are jumping trout difficult to catch?

Trout that are jumping are often very difficult to catch because they are not in a feeding mood.

In most situations they are in a state of distress, usually being chased or are migrating upriver in search of their spawning grounds.

The only time, where it might be easy to catch a jumping trout is when they are feeding on hovering insects. In such situations, a well-presented, high floating dry fly is the best option.

Some overly enthusiastic young trout also leap from the water after hatching mayflies. Sometimes, the biggest rings on the river are caused by the smallest trout.

If the trout are refusing your dry fly, I suggest working on your presentation. Make sure the fly drifts directly past the feeding fish. Also, make sure, there is no artificial drag and keep the tip of the fly line well out of sight.

Trout jump to feed upon hovering insects like Damsel or Dragonflies

I find nothing is more relaxing than watching trout leap out of the water to grab a hovering insect.

When a feeding troup leaps clear from the water, they are usually after a damsel or dragonfly that had stayed in one place slightly too long.

It does take quite a bit of luck, skill, and the right conditions. But it is actually possible to catch trout as they leap out of the water. If you can hide between tall grass and reeds, and with the assistance of the wind, it can be possible to suspend a fly directly above the water. This is not an easy way to catch trout but is a fun challenge that is extremely rewarding if you manage to pull it off.

If the trout are just poking through the surface they are feeding.

If the trout are just breaking the surface, like in the video below. They are likely feeding upon an insect hatch. Usually the adult sage of mayflies.

If the trout, for the most part are remaining beneath the water, and just causing swirls on the surface. They are likely to be seeping emerging insects just beneath the surface. It is important to match your fly choice with the stage of the hatch the trout are targeting.

Why do trout jump when they are hooked?

Trout jump when they are trying to escape. This is why hooked trout often go crazy, going on multiple jumps and long runs. I feel brook trout and Rainbows put on the best aerial display. Such displays can be quite exciting for the angler, but it must be traumatizing for the trout trying to escape.

To prevent a jumping trout from breaking off, it is important to set your drag lightly, allow the running fish to freely take line. Otherwise, a snapped line is a real possibility.

Trout and Salmon often jump when evading predators

Trout also leap from the water when they are trying to escape from predators, if a large pike, bass or Otter charges into a school of trout they can scatter in all directions. Including high in the air. If trout start to jump out of nowhere, chances are they are being chased by an underwater predator.

This can also be a great time to cast out a large streamer or lure, and try to catch the monster that is hunting the trout. Hopefully, you brought an 8wt because you could be in for a serious fight.

Fish suffering from thermal shock often jump

Ever watched a trout stocking take place, or rescued trout from a warm drying pool into the main river? Sometimes the release trout will dart around crazily, and leap all over the place. Sometimes they are just terrified and just trying to escape.

But, if the temperature difference between the storage tank and their new pool is too different they can go into thermal shock. This can cause a wide range of strange behaviors, including jumping and flapping all over the place.

Stock truck operators try to limit the amount of thermal shock by only releasing trout into water within 5 degrees F of what they are use to.

Migrating trout, Salmon leap from the water to clear obstacles

If the Salmonoid are swimming upstream and leaping over obstacles such as waterfalls or dams then they are migrating, usually on their spawning run. This usually occurs in the spring for Rainbows, and in the fall for Brown trout. The trout have breeding on their mind and not food.

If you really must catch one, then here are some tips.

Migrating trout, as spawning approaches usually become more aggressive. So if you can present a lure or spinner, right into their ‘personal space’ they are likely to strike it out of aggression.

They often gather in the plunge pool, downstream of the obstruction. This is the best water to fish your lure through.

Just be careful to present the lure with enough finesse not to spook the trout instead.

Do trout jump to clear their gills and bodies of debris and parasites?

Will, trout jump to try and escape predators, including a hook in their mouth, but unless they are in a mad panic I do not really believe they will leap from the water as a way to clean themselves of parasites or debris.

I have never seen it.

This question was bothering me. So I did even more research to try and find the origin of this belief. My conclusion, is that this misconception might have something to do with research into treating Atlantic salmon for sea lice.

The researchers sprayed a pesticide chemical onto the water surface, then encouraged the Salmon to leap through it in an attempt to coat their bodies and remove the lice. You can read more about the experiment here.

Do trout jump to stabilize their swim bladders?

I have read, that trout sometimes jump to stabilize their swim bladder. I personally find this difficult to believe, because if a trout surfaces too quickly, leaping out of the water would only increase the relative pressure further, increasing any potential discomfort.

Unless someone can prove me wrong. I believe this is just an old fisherman’s tale.

How high can trout jump?

While researching for this article, I read the claim that trout can jump up to 15feet. That seemed impossible for fish rarely longer than a foot, even elite human high jumpers struggle to jump half that.

So I investigated further and discovered that the figure was from a report that brook trout are able to overcome barriers such as waterfalls up to a height of 15 feet. So, yes, trout are not capable of a vertical 15ft jump, but under the right flow conditions, using a combination of jumps and high speed acceleration they can get over a 15ft high obstacle. Still very impressive.

That makes a lot more sense, trout certainly can not

So just how high can trout jump vertically?

Well, this is difficult to measure, and there is certainly quite a few anecdotal reports of trout jumping over 10ft.

One experiment, in laboratory conditions, found that 20cm (7.8”) long brook trout could jump over a 72cm (28”) high waterfall. This is over three times it’s length so quite impressive. Brook trout in the wild have been reported clearing higher obstacles. It largely comes down to the depth of the pool, and the velocity of the water. The faster the trout as it leaves the water the higher they can jump.

The National Park Service, on a factsheet about Yellowstone trout claims that Rainbow trout are capable of jumping up to 5x the length of their body. So it is easy to imagine a foot long rainbow could clear five or so feet out of the water.

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