Transducers and fish senses?

[fishndirk]

Often times while sitting there ancored off at a fishing hole I forget to turn the depthfinder off and im usually 2 beers too lazy to go over and shut it off but then I wonder, "Do the fish detect the pulses from the transducer and if so does this scare them away". I know it sounds stupid but just think of all the other stuff they detect with their lateral line. Does anyone have a definate answer to this?

 

[jigngrub]

Re: Transducers and fish senses?

You betcha!!!... but it really depends on how powerful your unit is.

I like to dropshot live bait for Crappie in the winter, fishing straight down.

Had a little 2400 watt sonar unit that I thought needed upgrading, so I bought a fancy smanshy 4000 watt color unit... couldn't catch a fish in less than 25' of water to save my life after installing it and taking the old unit off!:facepalm:

Put the old 2400 watt unit back on after a few months and started catching fish in 10-20' of water again.

I've found that if you're long line/flat line/downrigger trolling/ planer board trolling or just casting away from the boat it doesn't matter that much.. but can make a bit of a difference... but if you're fishing directly beneath the boat like drop shotting or jigging it can make a huge difference if you have a powerful sonar unit!!!

Your results and mpg's may vary... these are just my findings.

 

[dingbat]

Re: Transducers and fish senses?

Can fish hear the sound waves produced by a transducer?

No, the sound waves are ultrasonic.They are above (ultra) the sound (sonic) that human ears are able to hear. Humans can hear sound waves from 10 Hz to 20
kHz. Most fish are unable to hear frequencies higher than about 500 Hz to 1 kHz. The ultrasonic sound waves sent out by Airmar transducers have frequencies ranging from
10,000 kHz to 2 Megahertz (200,000,000 Hz), clearly beyond the hearing of fish. However, most people can hear the transmit pulses of our 10 kHz transducers.

http://www.airmartechnology.com/uploads/installguide/Theory_of_ Operations.pdf

A friend of mine is a diver. He confirmed that you can not hear a sounder under water. What he will tell you is that every little noise in the boat is multiplied many times under water. He said in 25' of water he can hear every word of a conversation going on in the boat above. The radio sounds like a concert hall.

 

[foodfisher]

Re: Transducers and fish senses?

^^^^^^ Now that helps. Thx

 

[JB]

Re: Transducers and fish senses?

Please recheck and edit your figures, dingbat. 10,000KHz is 10 MHz, 200,000,000 Hz is 200MHz. You are way beyond ultrasound and into radio frequencies.

EDIT: I went to the Airmar website. The errors are in their text, not your head. The actual frequencies used are about 10KHz to about 2MHz.

Peace.

 

[fishndirk]

Re: Transducers and fish senses?

So basically, the pulses emmitted by a transducer are at a much higher frequency than fish are capable of hearing and I should'nt even worry about it? Would'nt really know from the fishing I do since I usually cast my bait way past the range of where my depth finder is sending pulses.

 

[fishrdan]

Re: Transducers and fish senses?

My experience, if I forget to turn off the sonar after fishing, I'll find it while securing the boat and trailer. Not from looking at the screen, but from hearing the ducer clicking away...

I don't run my sonar while "trophy fishing" as I'm trying to be as stealthy as possible, superstitious I guess... If I'm dink fishing, I run it,,, and catch a lot of dinks.

I guess that wasn't the definitive answer you were looking for though

 

[fishndirk]

Re: Transducers and fish senses?

HaHa, yeah not really. You always see those huge "beep, beep" fishes under your boat while your sitting there ancored off but who knows weather those are fish or just trash under the surface...course their only under you for a few seconds so who knows weather they hear it or not. Too bad we cant be fish for a few days...the stuff we would learn! HaHa

 

[seapro235]

Re: Transducers and fish senses?

I usually turn off my sonar when i anchor ... I don't think fish respond to sonar as much as boat sounds, turn off the music and keep deck sounds to a minimum... also, if you ever want dolphins to come along side your boat, turn off your sonar !