I recently upgraded my bow with a Garmin Echomap 93sv UHD and noted that it has an easy way to suspend sonar transmission. That got me to wondering, does the ping put fish on high alert?  

Sometimes

When I drop my trolling motor,  my 360 imaging transducer starts spinning,  MEGA Live starts pinging, the 2D sonar built into the TM starts pinging,  and my trolling motor prop starts spinning.   Do the fish know I’m there?  I have no doubt they do.  I recently watched three fish on MEGA Live leave the cover they were on and swim 15 feet directly toward my trolling motor.   I guess they wanted to see what all the commotion was about. I wouldn’t be surprised if some of the smarter ones swam in the other direction.  

If I'm fishing my Solix/360 is pinging.

Sonar only has a positive effect here, hypnotic.

I vertical fish a lot. I’ve been on top of fish in 15’ of water and caught them. If they even aware of the sonar it doesn’t Look like it affects them. YMMV

Watch this video and see if this helps answer your question. 
 

 

Even if someone could show evidence it does spook fish and leads to fewer catches, I'd still use it. Vertical jigging and watching the screen is too much fun.

I think its probably more so the hum of that blade on the trolling motor making some noise than the pinging of sonar off a transducer.

Hard to tell when bass fishing, especially when fishing in cover.  When salt water flats fishing, this is much more apparent.  This is the reason flats fishermen pole their boats.  Any noise whatsoever will spook flats fish.   Sight fishing for tarpon, bonefish and redfish is a stealth game.   The water is very clear and even waves from a boat will run them off.  I don't see that happening in bass waters. 

I read somewhere that whales and porpoises are negatively effected by sonar. 
 

I get it that they are mammals and the sonar on a submarine in the open ocean is far different than what’s on a boat in a lake. 

But in my narrow minded thinking mode,

I would think there has to be some type of effect…

 

 

 

 

Mike

31 minutes ago, Mike L said:

I read somewhere that whales and porpoises are negatively effected by sonar. 
 

I get it that they are mammals and the sonar on a submarine in the open ocean is far different than what’s on a boat in a lake. 

Absolutely true.  Whales use sonar to communicate.  The navy has been using a deep-sea heavy banded sonar called Sonic Sonar and it can actually damage the communication body parts of whales.  Think of it as a constant noise in your ears that never goes away.  It would eventually cause health issues.

1 hour ago, gimruis said:

Absolutely true.  Whales use sonar to communicate. 

Yeah and dolphins have had forward facing sonar for a long time.?

My recollection is that results from tagged fish studies suggest that some fish scatter at the sound of the sonar.

Fish are capable of learning, if even on a basic level.  Your dog knows when you open the bag of treats that something good is about to happen.  Can a fish who has been jerked out of the water by a hook learn to equate certain sounds with this experience?   Since I was a small boy, I was told to fish as quietly as possible.  I was scolded for shuffling my feet on the bottom of the boat or opening my tackle box too loudly.  I make long casts and I don't run my trolling motor in the cover I am fishing.  Does this help me catch more fish?   I don't know because I don't catch the fish that I scare off.  

Good question. One that I haven't thought of before and I couldn't tell you if it's good or bad. I still keep it on.

I have heard pros say they turn off the ping when in shallow flats and bays.  There is so much we don't know about what sounds bass react to...positively and negatively.  My limited observations relate specifically to a couple of examples.  I have trolled in clear water at constant speed and had bass swim parallel for hundred yards, even with slight changes in direction.   However, when I changed the speed, even slightly, they'd peel off immediately.  When I'm in a kayak in shallow pad fields, I am far more successful just plowing into a spot and then sitting quietly for a few minutes before making a cast or pitch, than if I just try to move along continuously,  fishing as I go.  So, I don't know....I typically leave the sonar on, but if I'm doing the shallow flats or pads thing, I'll sometimes pause the ping.

I don't turn mine off in the kayak.  I am more worried about the trolling motor than the ping, specifically the turning motor and not the prop motor.  The prop on a low setting makes very little noise.  The turning motor is a higher pitch whine that, while above the water, I'm sure can be heard under it. 

 

That said, fish can certainly hear it and feel it.  In another thread I told the story of when we were diving the last time.  We were under the boat in 60' of water and when I hit the cone of the transducer it was like a drum in my ears/sinuses and basically every air cavity could feel it.  If we stayed too long (like more than 10 seconds) I started to get a headache.  I don't know what transducer or unit it was since it was a saltwater boat (used for both diving and fishing).

Situational, but more often than not, I leave my sonar on. The only time I may turn my sonar off is when I can actually hear the pinging of my 360 as I am dropping it into the water. The condiitons have to be pretty dang calm for that though, and most of the time, I will just turn my Hydrowave on a very low setting to cover my tracks... Does it work? Who knows... The conditions are tough anyways ?‍♂️

Sound travels much faster in water then air, at least 4 times faster. There isn't any doubt the bass hear your sonar, they also hear your trolling motor, outboard motor and boat hull from a long distance via lateral line senses.

Bass accustom to the white noise are less affected then bass in quite environments.  Best example is bass located in and around marinas would be less alarmed then bass far away from boat traffic.

I assume the bass can detect my presence and try to avoid pinging them with sonar when trying to catch them. Locate the bass and bait with sonar and return quietly later.

Tom

I don’t think that their hearing range goes high enough for them to pick up the sonar pinging sound.  They may not even be able to hear the sound made by a rattling bait.

https://www.bassresource.com/fish_biology/how-bass-hear.html#:~:text=possible food source.-,Dr.,t hear high frequency sounds.

The study is on hearing however bass also use their lateral line to feel (hear) vibrations, that how a blind bass finds and strikes your moving lures and hunts live prey to survive.

Our bass boats have trolling motors the feel (hear) the prop vibrations, your OB prop etc.

I have watched big bass take off when switching my Sonar on, so they detect it. Your TD puts out a thumping pulse of frequency, put your hand under it and you feel it.

Tom

The modern bass boat's sonar is like a navy destroyer moving through the water. I have little doubt that all that pinging and beeping puts the fish on alert, if ever so slightly. In a rowboat, with no motor and no sonar, a rattlebait hits fishes senses so much differently than if the same bait is being presented from a boat with sonars and props. They don't react the same at all. 

I doubt bass can hear the actual frequency of a sonar.  It's WAY up there.  It starts off around 80kHz on most freshwater sonars and runs up north of 800kHz.  Even a dog can't hear above 60kHz.  Most fish can't hear above 5kHz, which means most fish can't hear as high as humans.  

 

That being said, there are other, lower frequencies that a sonar puts out.  You've probably heard a sonar clicking before.  It's not the frequency of the actual ping, but a residual tone far below it.  Obviously, this click is in the human audible spectrum, and might be detectable by fish.  However, as you can tell, it's not loud.  The question is, do bass hear it, and does it mean anything to them?  A lot probably depends on what else is going on in the water and how far away you are.  High frequencies don't travel as well as lower frequencies.  As you've noticed, when you put your head underwater, the high frequencies get diminished pretty quickly.  And, if it's windy or there's a current, you'll have the sound of waves to mask you.  And there will be the sound of waves crashing against your boat, plus the sound of your trolling motor, and you walking around your boat that will also give you away at much lower frequencies that bass are much more likely to be able to hear. 

Given the frequencies, I would be impressed if bass can hear them to be honest.