scary depth sounders?

[Hobes]

Hmmm whilst out fishing the other day, got to wondering about depth sounders, fish finder etc.... They all work off sonar principal of soundwaves.


Just wondering does anyone know if these soundwaves spook the fish below?

[cod_botherer]

“Bony fishes have an inner ear for equilibrium, detecting acceleration, and hearing. There is no external opening to the ear. A fish's soft body tissue has about the same acoustic density as water; sound waves travel through soft tissue to the ear.

There is great variation in hearing sensitivity, bandwidth, and upper frequency limit among bony fish species. The hearing range of the cod Gadus morhua is about 2 to 500 Hz, with a peak sensitivity near 20 Hz-probably typical for most bony fish species.” *

Your sounder is running at about 50,000hz to 100,000hz and up.

Should be OK I think.

*Seaworld web site

[Volvo]

:)Just from experience i tend to think so ???..
Cheers

[Hobes]

Hmmm do other people turn their sounders off when at anchor or leave them running all the time?

[cod_botherer]

Just run them all the time Hobes, you might see a mermaid ;)

[Aaron_Fogarty]

Thats the best explanation Ive ever heard COD B, should wrap this topic up.
I usually turn mine off though, for no educated reason. Just a habit or supastition I guess
Regards
Aaron

[devocean]

Dont think so from spearfishing experience.

[baldyhead]

A couple of years ago I saw a fisher who was setting a net around some very large tree type snags in a river way up north and was interesting to watch. He and his mate would run the 25 foot drop net around the snag then paddle the 18' dory into the middle of the net and you could actually see the fish hitting the net and meshing. NO they were not banging the water with anything nor were they "plonking" the water and they were not flogging the floor of the dory.
The fisher simply turned his lowrance X70 on and watched his net fill up.
I watched him do this for about 5 days and went to his camp and over a few rums he told me that he had been 'scaring fish' like this for years and that it worked every time. He said that he would sound the snag 1-2 days before he put his nets in and then clean up.
From this valuable lesson I have learned to turn off my sounder once I have located and anchored. I believe this works in 120 feet of briny also.
cheers baldy

[dfox]

I dont care what scientists say, turn on a 1 kw sounder during a big red bight and watch them go quiet.. :-[ seen it happen to often to be a coincidence...foxy