Affect from sonar?

[BobT]

Depth finders, fish locators, flashers, however they are referred, are all sonar units. They emit a sound pulse wave that reflects off objects and the time interval between sending and receiving the reflected wave is used to determine the distance to the target. Power up your unit on a bench and you can hear the ticking emitting from the transducer. It’s actually quite loud and in water is magnified significantly.

Has there ever been any research or evidence about how the fish may be affected by this? In other words, has anyone been able to determine if the sound pulse spooks or attracts fish?

Bob

[fiskyknut]

It may attract the fish? Pikes anyhow as I have had my transducer attacked on the LOTW nearly pulling the whole unit into the hole!!!

[Jorgie]

I've heard the ticking attracts jumbo perch.

But I don't know of any scientific studies that have tested this.

[Ray Esboldt]

Bob,

I've thought about this many times as well. I have never read any scientific evidence one way or the other. I have had several days where I've turned my flasher off and caught decidely more fish. I would like to know as well.

[JP Z]

From what I've experienced it really depends on the depth. I know folks who when fishing in less that 6' of water won't use any electronics. Ice fishing or from a boat. But it really depends on the amount of pressure the fish are feeling I would think.

[Eric Wettschreck]

Like Fisky I've had my trasducer attacked by a northern. Like Ray I've turned my Vexilar off and caught more fish. Like aboot everyone in the midwest I've turned my Vexilar on and caught more fish.

And there ya have it, it's clear as mud.

[Gissert]

What Fisky said. I had a 40 inch class pike grab my transducer in Sabaskong bay on LOW and give it a nasty shake.

There have also been times, mainly suspended crappies, where the flasher may have had a negative effect. Not real sure about that, however. With out the flasher, I would never have known they were there.

[Duffman]

I think it all depends on the body of water and the species involved. On seldom fished waters, I don't think it makes much difference; the fish have not had the opportunity to associate the sound of a transducer with the concept of danger. I think on waters that are heavily fished the fish might be changing their behavior to avoid transducer activity. It might not be the smaller species of fish like sunnies and perch, but the bigger predator fish.

Guys were reporting that the walleyes on Mille Lacs were becoming underwater camera shy, if the fish can associate cameras with possible danger, why not sonar sound. When I'm fishing in my canoe, I can see carp off in the distance react alarmingly the second I turn on the trolling motor. I was icefishing a metro pond RIGHT next to a busy road, there was a bunch of bullheads on the camera and every time a car with a thumping subwoofer passed, the fish would dive straight to the bottom.

In certain situations, there's no doubt in my mind that sonar can affect the fish negatively. I do turn mine off when fishing shallow at times, and also while laker fishing at times. And I've had better luck while it's off; it's with me at all times, but not necessarily on.

[Iceboy]

I've had the same thoughts before, though I haven't seen any conclusive evidence one way or the other. I've always wondered about the times when I've had "sniffers" come in constantly with nary a bite, that perhaps they were on to me and had picked up the sound of the transducer. Doesn't mean I will fish without one, but it might be worth turning off for periods of time to see if the sniffers don't start biting more.

[Cheeser]

Trout are very sensitive to electronics. I know a bunch of guys that refuse to use them while fishing for trout. I use my flasher for finding depth, but then I'll shut it off.

--Mark

[icegrogg]

Now all MARCUM should do is make their LX'S trasducers put out sound waves with sounds like the BIOSONIX!!!! Make the units so they will except a chip and there you have a $$$$$$ maker.

[Jason Hubbard]

thats a pretty expensive depth finder.but anyways i fish next to people without a vex all the time. i never been out fished by someone with out one..that is a fact.my brother would get so frusterated and peed off he bought a vex just so he could keep up.i love my vex

[HarryG]

I attended a Laker seminar at the St Paul Ice Show. They said that lakers are much more sensitive that other species of fish. The speaker recommended that you turn off your flasher while fishing for lakers. There must be something to it. But they also said the auger in some situations would cause them to bite.

[alwaysfishin]

it's easy to turn one off, but tough to do. i think i'll just keep mine on. until al lindner tells me not to!!!

[dec]

something to think about. fish don't hear the same as us. they have a very limited frequency range. its unlikely that a fish has the ability to hear in the frequency range that a sonar transducer is operating. its more likely that fish are responding to other sounds generated above the ice such as: shuffling of your feet, power augers, music, atv's etc. all of these activities produce sounds that fall within the frequency range that fish will respond to.

duane cummings

[fiskyknut]

Hey Duane.....What is it about flashers and 200mhz transducers on all of them? I have an old Clearwater pro I use on occasion that runs a 150 mhz transducer and it picks up no interferance at all no matter how close, what type, or how many other units it's around. Never had it near another 150mhz Clearwater pro though! Am I correct in assuming the IR buttons on Marcum and vex products modify the frequency of sound produced slightly to avoid picking up interferance? And if so how much tweaking of the sound is needed, and how much frequency change occurs thru the 12 levels on an LX5?

[Northlander]

In shallow waters and with certain species it will spook them. I never thought that it could but had a friend fishing bows in shallow and it spooked them.

[jig n' jerk]

Cheese,

I have also heard from many avid trout fisherman that trout are extra sensitive to sonar. It makes sense to me as I have read a few articles on trout being very susceptable to vibration (or sound waves).