Can Contrails Predict Fishing Success?

My family likes walks. We walk almost every day – sometimes multiple times per day. The fresh air, exercise, time we get to spend chatting with each other, and the exciting things we see make every walk enjoyable and interesting. It’s our go-to way to get outside and get into nature. Two days ago, I wanted to walk in a nearby prairie at sunset because the light across the fall landscape is especially beautiful this time of year.

Dried flowers dot the fields,

dainty grass plumes sparkle in front of the lowering rays,

and the family seems to feel the magic just as I do.

But, this is not what this post is about. This post is about contrails and fishing.

At the very western edge of the prairie one can find a clear lake with a sandy bottom. The kids love to explore the shores of the lake when we visit the prairie and we did just that two days ago. While the kids ran up and down the shore, made clouds out of cattail fluff,

and searched for lures that others had unfortunately lost while fishing,

my husband offered an interesting bit of information:

“Too bad we are not fishing right now.” he said (this after he and my son had been shut out three days in a row – well, except for a few mudpuppies).

“Why is that?” I questioned (thinking there may be more to this statement than the obvious fact that he’d like to fish all day – every day if he could).

“You see those vapor trails [contrails] that the airplanes are leaving in the sky, and how they are slowly spreading out?” he asked.

“Yes?” I questioned.

“They indicate good fishing.”

“How is that?” I asked, “And, where did you learn that?”

“I must have read about in one of my fishing books, but I don’t remember where or which one.” he replied.

To be fair, my husband has read a plethora of fishing books – books about fishing technique, fishing memoirs, fiction books about fishing, and he even studies lake and river maps.

He continued: “It has something to do with pressure changes.”

Today I explored this theory further using my favorite learning tool – the World Wide Web.

This is what I found:

A contrail is: a condensation trail left behind jet aircrafts where hot humid air from jet exhaust mixes with environmental air of low vapor pressure and low temperature. The result is a cloud similar to those that you see when you exhale and see your breath outside.

Okay, so how does this affect fishing?

I found a simple explanation in a bass fishing forum on BassResource.com. BassChaser57, a self-proclaimed “airline pilot by profession, BassChaser by passion,” stated:

There are lots of variables i[n] bass fishing such as temperature, cloud cover, barometric pressure, wind speed and direction, moon phase, fishing pressure, rising/falling water, muddy water, etc. There is one variable that I have used over the years… it is simple and it works.

Few of us can spend as much time on the water as we would like so I try to maximize my quality fishing possibilities. I do this by watching jet contrails (the white trails left in the sky by jets.) When I see the sky crisscrossed by contrails I go fishing and expect to find active bass.

The explanation is simply that there is high level moisture meaning there is an approaching weather system. Many of us realize bass get active with an approaching storm or lowering barometric pressure, the contrails will tell us the same thing without having to be able to see the weather channel.

The next time you see the contrails in the sky, try to go fishing and expect the Bass to be active and prove to yourself that contrails=active bass.

Dan Johnson from In-Fisherman magazine defines barometric pressure more thoroughly…

In a nutshell, barometric pressure—also called atmospheric or air pressure—is the weight of the air pressing down upon everything on the planet, including fish and anglers. Lest you think such a load is light as a feather, consider that a square-inch column of air rising from sea level to the top of our atmosphere weighs about 14.7 pounds.

Even slight changes in barometric pressure can cause big changes in fish behavior. According to Spud Woodward, Assistant Director for the Georgia Department of Natural Resources Coastal Resources Division, fish sense pressure changes through their air bladder. He goes on to explain:

Fish that have small air bladders, such as kings, Spanish mackerel, wahoo and dolphin, aren’t as affected by barometric changes as those with large bladders, such as trout, redfish, tarpon, grouper and snapper… That’s because fish with small bladders have a body density that’s closer to that of the surrounding water. They don’t sense the pressure changes as dramatically, so their comfort levels aren’t drastically altered. However, many things they eat have air bladders, and that alone could have a big impact on where you might find them and how they’ll behave.

For example, zooplankton and phytoplankton have air bladders and can be caught off-guard by pressure changes causing a feeding frenzy among minnows and other small fish, which in turn brings out larger fish to eat.

Woodward continues:

Fish with large bladders quickly sense when the air pressure is dropping, because there’s less pressure on their bladder. And when there’s less pressure squeezing their bladders, the bladders expand a bit. When their bladders expand, fish become uncomfortable. They relieve their discomfort by moving lower in the water column or by absorbing extra gas in their bladders.

These stresses cause fish to forget about eating, and instead focus on finding a depth where they can find comfort.

Finally, Woodward explains the pressure changes where contrails are most evident – the period just before a low-pressure system sets in. Just what I was looking for.

Let’s say we’re experiencing a prolonged period of high pressure and the fishing has been good. Then a cold front heads our way. Ahead of the front is low pressure. The fish can sense that the barometer is about to drop. So, right before the high begins to dissipate and the barometer falls, the fish respond with a change in feeding patterns. They’ll often feed heavily right before the pressure drops. As it does, they become more uncomfortable and feed less aggressively. When the front passes and high pressure moves back in, the fish may not feed aggressively for at least 24 hours, since they’re still adjusting

The day after our walk in the prairie, my husband got a text from a friend depicting 1 of 30 beautiful rainbow trout that had been hooked and released. This just so happened in the same area my husband and son had fished days before.

I laughed thinking about the contrails my husband had shown me the day before. The trout must have been on a feeding frenzy as our temperatures had plummeted 15 degrees in the last 24 hours – the fish knew what was coming.

My family and I went on another walk this evening, and we were all dressed in our winter jackets, hats, and mittens,.  The light winds made the 45-degree temperature feel extra chilly. The sky was bright blue, clear, and free of clouds – low pressure had settled in. I caught a glimpse of a plane high in the sky, but this time the contrail was disappearing quickly behind the plane. There were no long streaks of clouds that lingered behind the plane.

I imagine the fish have probably settled in deep, trying to maintain comfortable bladder pressure instead of searching for their next meal.

The things we learn on our walks.

Have you learned something new on a recent walk? I’d love for you to share what you have learned in the comments below.