Electrical Current from a Trolling Motor and Asian Carp

You can take a length of copper pipe and jam it in the dirt for ground and then test the water with piece of copper wire connected to pos...The reading if you get one would probably vary wildly.....You might test for frequency generation by the boat, it's possible the noise is unpleasant....but not terrifying...lol

Interesting, Maybe, and I'm just guessing, the trolling motor doesn't make enough noise to interfere with their echolocation senses; if they are able to sense the location of the noise, which may sound like a predator to them, they can swim away from it. The boat motor would be information overload. They are pretty loud underwater and would reverberate from every direction. And the paddle on the side of the boat? He might have just sneaked up and freaked them out.

Or it could be a short!

You don't sneak up on these fish...ever! They can sense movement, vibration and once they are caught and tagged....they hardly ever get re-caught. learned behavior with gillnets and trammel nets.

There's got to be something to the electric trolling motor....what I am not sure.

The guy who experienced this has been dealing with these fish every day since the late 90's. He knows when something new is happening.

thank you and keep the suggestions coming.

I've been involved with the removal of these fish for 4 years now. The use of electricity has been a proven method of making these fish move one way or another.

But there are some other gears that could use a low does of electricity to help capture the fish and this trolling motor thing has me intrgued.

At around 3:30 they hit a log and have to stop. the net on the Port side ( left has NO fyke ( funnel type retstriction that holds fish from escaping). Most all just swim out. Skip ahead to 10:40 and you see the Starboard net with a basket type fyke and still a load of fish in front of it.

These fish never stop trying to escape. Their endurance is like a Blue fin tuna.

Mild and safe electrical current could be very helpful in working to control these fish.

How mild is what i am looking for..

You should contact the fisheries departments in Australia. They have been using electrical current to control "euro's" (European Carp) for some time now. It is well documented and highly effective.

They float to the surface and can be caught and removed with no damage to the endemic (desirable) species.

In Aus, if you catch Euro on a line or in a net it is illegal to return them to the waterway. (I'm not a fisherman, but I think it's even to the point where it's illegal to NOT destroy them if they are caught.)

Same with these fish. You can not put them back.

Its a very prolific species.

So far, the messsage I am getting is that there is probably no leak in current from the trolling motor..

They use curent here also. Its a big issue and a huge expense. The current that stuns them, is ONLY produced in a field about 2 meters in diameter . They get about 100 fish and then 10,000 swim away.

We are looking at 'nudging' not stunning. This way we nudge them into a select spot and then we can deal with them in a huge school. They are so spooky. Their panic mode is enhanced by a pherome they discharge from a special galnd. Its almost like the Killer Bee air borne pherome.

Anyway, thank you for information.

If its not an electrical current, then there must be something to what the trolling motor is doing in terms of vibration.

Different hull designs are known to affect how fast these fish spook ..... different types of displacement ( wakes).

Mother Nature is so full of mysteries? Folks should have left these fish in Asia where they were kept under control by 1000's of folks constantly catching and eating them.

Not so here in the land of the Super market and chain stores.

Cathodic protection systems have evidently been installed on a number of bridges in Australia. These systems use a very low voltage (around three volts) to forestall corrosion on the submerged metal parts of the bridge. It apparently has also driven all the fish away. This suggests a simple experiment your customer could try himself.

For this experiment he'll need a three-volt battery pack like the kind you can find at Radio Shack. Also 20 feet of insulated, 20 AWG hook-up wire (also available at R.S.), and two batteries.

Cut the wire into two equal lengths and solder one end of each wire to the battery-pack terminals. Strip about 12" of insulation from the other two ends and drop them in the water at opposite ends of the boat. Insert the batteries and note how the carp respond. If the carp have highly-sensitive lateral lines as reported, they will respond. Also note how the other fish respond.

If the carp are not driven away as before then it may not be an electrical effect that they're responding to. If it isn't then they're responding to either the sound of the motor/prop or its magnetic field. I believe the electric motor in trolling motors is right behind the prop, yes? Or is it at the top of the assembly?

I suspect it is the sound of the motor or prop, quite honestly. Thing about trolling motors, there's really nothing in the water that would make an electrical circuit through the water. This suggests another experiment.

For safety, remove the prop from the trolling motor (if possible) and run the motor on-board the boat with the business-end of the motor touching the bottom of the hull. Placing the running motor in contact with the hull will conduct the sound of the running motor into the water but without making any electrical contact with the water. We're trying to isolate one of several potential causes for the carps' behaviour.

Note how the carp behave before and during the motor run.

If the carp don't react in the same way, it could be prop noise. To see if this is the case, lower the business-end of the trolling motor - sans prop - into the water (provided of course that removing the prop doesn't cause the thing to leak) and run the motor. If the carp don't react the same way, then it is most likely prop noise. The lateral lines in fish are sensitive to infrasound and low sonic frequencies (<100 Hz). Possibly it is this low-frequency prop noise that caused the carp to herd off in one direction whilst being quiet enough where they didn't panic. Have your customer re-install the prop and then repeat the experiment. If they herd off, you've likely got your answer: low-frequency prop noise.

Thank you for that well thought out experiment. I have already made arrangements for a test of really low end electricity ( which we know already HIGH END is being used to stun and kill the beasties ( Smith Root Electro-fish shocking units) and another test with a variety of devices that produce different amounts of magnetism.

The high end noise test is already a given I believe as any major sound that hits the water send them into a frenzy.

Your example of low end noise has yet to be experimented with.

Some others here also indicated low end noise from both the small spinning prop and the hull design. I am partial to the 'pontoon' hull design and the low speed of the trolling motor. who knows. but we are getting closer.

Thank you for the time and response.

A1) If it did, then it would be well 'on its way out'.

A2) Given A1, Q2 is not applicable.

Hi netmaker,

I realize now we have Asian Carp here too, but I have never seen or heard of a display like the you-tube video above. I wonder how they get upstream, past the locks and dams. What a nuisance and danger these will be for water skiers, jet skiers, and the bass boats that run 90 mph. (I see from you-tube someone has already invented extreme water skiing.) And the threat to of all the game fish!

I guess I will have to take up bow fishing. Any suggestions on where they would like to hang out on a large body of water like Ky Lake?

The fish spawn several times.

The Silver carp jump....the Big heads stay on bottom.

Both species eat plankton.....tons of it per year. They clean out the plankton ( both zoo and phylo) and leave nothing for the forage fish ( minnows and such) to eat.

Food chain break occurs.

The carp eat themsleves out of house and home after awhile and become putrid looking. Disease sets in and you have a whole other problem in your water way(s).

I was chastized a while back for being insenstive to these fish. Guilty! They are destroying , possibly beyond the point of recovery, numerous species of our native fishes.

I've seen these fish back in the day ( triploids: XXX chromosones and can not breed) get to 80 lbs in a fish pond. They will follow a bush hog along the berhm of a levee and EAT THE GRASS CLIPPINGS when all else is gone.

There have been folks knocked clean out of a boat by a 20 lber. launching itself in the air while the boat is travelling 30 knots.

Water skiers and jet skiers stay clear. You will get broken ribs, teeth and possibly knocked unconscious.

Window shields on boats, cowl covers on outboards and anything laying inside the boat are fair game when these acrobatic fish come flying in.

The glands leak a pheromone and like killer bees, they go into a shreken response and launch themselves in ANY direction all at once. The videos are nothing compared to being there. Its incoming missiles and no where to hide.

As for bow fishing ... dim the lights. they are really photo sensitive. If you get the right ( Small light) and skim it across the water, not angle it too directly, you will see their lips sucking the algae and plankton.

Shooting at them skeet style is a 2nd degree manslaughter or 1st degree Negligent Injury case just waiting for a lawyer!

They have made it to the Gulf of Mexico shoreline too.... brackish water, just inside the sand dunes near Vermillion Bay and even Barataria Bay below New Orleans. They may not stay in that brackish water long, but they are still there.

There is no escaping them, like the old 1950's BLOB, they are slowly creeping everywhere.

.........as I always say....I am NOT the expert. I just build gear for folks who are.

Your description put me in mind of a pride of lions patrolling the edge of a herd of impala. The impala have two reactions: as long as the lion make no sudden moves, the herd shifts subtly to maintain an escape distance between them and the lion and they carry on munching. If a lion charges, then the impala go into their asian carp routine.

Suppose that the fish (lateral lines?) can assess the speed of approach. The electric trolling bateau appproaches slowly and the fish retreat slowly. The bang of an oar on the gunwale sets them into leaping mode. With the outboard the speed of approach exceeds the ability of the fish to maintain the safety distance so they go into impala mode.

A crude test of this idea is possible. Your customer could proceed with the outboard at a very slow rate - no faster than the troller - and see if the fish get to leaping. Similarly your customer could proceed with the electric troller and give the gunwale a bang with the paddle.

Excellent analogy. This could indeed be something they are learning, as once caught fish with radio tags are seldom caught again....at least Not quickly.

I am suspect that the bateau he was in was not a true bateau but one of those molded fiberglass 'pontoon' hulls. The double keel would NOT make the same noise as a true, flat bottomed bateau.

Thank you again.

stupid question but what preys upon them in their normal habitat? are they susceptible to a disease that native fish are not? could you use a genetically engineered pathogen to kill just that species of carp?

They come originally from the Yangtze River system. The locals eat them to the point of keeping their numbers under control. There are reports (un-documented as yet) that the jumping behavior is something they acquired or was enhanced once let loose here in the USA.

In the US, we are not that hungry. We still can be picky about what we eat. However, it might come to that one day(?)

I am sure they could come up with deadly pathogen. HOWEVER....getting permission to use it would be a paper chase night mare. Never happen.

Right now, the Big Heads are looking very putrid. they have suffered the worse case of eating themselves out of food. Some fishery folks said just to leave them alone and in 10 years the problem will be over....OK, so what about all the damage they can do to the ecosystems they infest in those 10 ten years?

One guy I do some work for in Kansas said that he would hit the YOY ( Young of the Year) class of fish real hard with anything that would catch them or kill them. His idea was to stop their numbers while they can not spawn . who knows.

Rotenone kills them off in the thousands.....and also gets game and native species too.

The first good video of a couple of dead Pallid Sturgeon and a few gravid Paddle fish might instigate legislation to stop even the gill netters from working on these fish. No one knows how political it can get.

If you watch the videos on You tube, you will see the gill net guys with HUGE fish in the 20 lbs range and larger.These are fish that are 28-32 inches long.

Now, watch all the other videos.....there are millions of fish in the 12" to 24" size that are NOT going to be targeted as they are yet too small for commercial use.Those critters can eat their way from New Orleans to Cairo, Ill. and every tributary east or west. Once the plankton is gone, the forage fish go, then the yoy of bass, crappie, blue gill and every other native.....we'll be left with dead water and dying fish.

To put it bluntly, there are only 2 kinds of locations east of the Rockies ; those with Asian carp and those who will soon HAVE Asian Carp.

Anyway, Mother Nature will balance it all eventually. Maybe the Snake Heads that are loose in the wild now ( and showing up in some eastern and midwest lakes) will eventually proliferate enough to clean up the carp.

OOops! Where is that edit button ...??? dang it!!!!

we call that "ca ce Pourri" in Cajun........ Stinky!!!

The fish meal thing has been discused for years.

Baader makes an assortment of fish-meal-bone separator that might work with these fish. Problem is like you said, location , smell and run off.

the other issue is how to transport. These local commercial guys can haul fish in their boats only so far and then they spoil. Unlike the catfish industry, the processors are NOT talking about sending trucks to pick up the catch.

Logostics are not in place. There is a processor who is handling these fish right now but only the extra large ones and only within his 'area".

Fish meal is the way to go with these....they just need to get past the politics.

A peak inside of one those catfish plants would show them how its done automatically. Of course these fish have lots of bones. But I'd be willing to bet that Baader has a solution for that too.

I wonder if some of your Red Bellies wouldn't acquire a taste for juvenile carp??

Stay cool.............I know its hotter in your neighborhood than mine. ha ha !

I'm thinking that its not stray current but the magnetic field generated by the motor. There has been some study of magnetic field effects on sharks.

http://en.wikipedia.org/wiki/Magnetic_shark_repellent

Excuse my ignorance. Could you maybe explain the difference in a magnetic field as opposed to an electric field? Joe 6 Pack language if you don't mind please.

I am thinking vibration from the different hull designs, then an electric leak of sorts, I never thought of a magnetic field. YOU are 100% correct, during my brief work with shark guys back in the late late 80's and early 90's they were constantly speaking of how they thought a shark could home in on prey by using magnetic fields. It was new back then.

These carp are so tuned in. their gas bladders are connected directly to their hard wiring so they can use that big @$$ bony head as a collection receptacle for any vibration or noise. Along with extra sensitive laterals these fish may possess a defense mechanism unparalleled except by maybe, dolphins..... who knows.

Magnetic fields??? I wonder how far they would extend and how far these critters pick up on that.

I am getting out of comfort zone with discussions of electric and magnetic fields so if you can, keep in simple. I ain't a dummy, but i ain't that smart either. ha ha.

they are related but different. an electric field can generate a magnetic field, and vice versa. this is a pretty good layman's explanation: http://in.answers.yahoo.com/question/index?qid=20080710215215AA3TS4j

You have an electric field when opposite charges get separated -- for example, when you rub a balloon on your head. It provides a force on the charged particles (electrons) to move back together again (hence, a spark).

A magnetic field is caused by moving charges, for example, electricity flowing through a wire. Electric current flowing through the motor create magnets in the motor which attract and provide the force that allows the motor to do work.

I think it's fascinating that these fish are affected by the trolling motor. I hope you find out what's going on. I'm sure we would all like to hear about it.

If there is profit in it, it will be exploited to the max.We(mankind) have made many species extinct by putting a bounty on their hides,head,and meat.What is needed, as suggested by others, is a commercial venture to process this abundant source of protein.Fish food, animal feed, fertilizer,etc.However, since they are bottom or trash feeders, they may have high levels of whatever pollutants are in the water.

This could serve a benefit by removing contaminates, but present a problem when processing them.

No easy solution here.

As for the trolling motor, having a smaller prop,it generates a higher frequency than a larger prop, and slapping the boat hull would generate a low frequency.Low frequencies travel farther than high frequencies, and because of this long-range, perhaps the fish are naturally tuned to a lower frequency.I doubt that many natural enemies would generate high frequency sounds when launching an attack.

I think a study of the frequency sensitivity of the fish might reveal some interesting insights into control.

for that matter, just blast the hell out of the water with thousands of watts of sound and pulverize their brains... problem solved. nice part, you can make the sound directional too...

.....not so far fetched..... I actually over heard some guy from Finland years ago talking about such a thing.

Not far fetched at all. The navy calls it SONAR.

... ha ha ha you got me on that one! Just not thinking today. Lunch time and i keep smelling that roast beef sandwich the wife is slapping together.............

I guess we could find out what frequency overloads their sensors and turn up the volume.

Didn't we have s discussion a year or so back about sonar on subs affecting whales and dolphins???

Yes, quite the controversy. I believe that the Navy has declared that SONAR doesn't harm aquatic life and are continuing to use it as before.

Those dead whales are just a little collateral damage.

actually you could use a low power or passive sonar to identify the targets autonomously and then blast the hell out of them automatically. think of it as a carp seeking missile....

TEXACANS..............always thinking of different ways to use a gun!

If you turn the power up high enough, it'll cook em too.... the cavitation in their brains will boil them from the inside.

the operative word, "thinking"

Hi netmaker,

I have been following along on this thread with great interest. We have the same problem but not yet to the same extent.

Sonar certainly works on mammals including divers. At close range the sets of the 1970s could blow a diver's ear drums. This is/was a great comfort to those of us working and living below the waterline.

The idea of the magnetic field intrigued me and I started thinking of how you could make a test field. I thought about a coil wrapped around the hull from stem to stern hooked up to a starter coil, battery and stuff like that. Then I thought this is a lot of trouble for a simple proof of concept test.

Then I thought what about a metal detector? That produces a magnetic field that is fairly directional. If these fish are as sensitive as they seem to be then maybe a metal detector held over the side and aimed in different directions could provide all the proof needed and possibly some fun as well.

Metal detectors are available for hire but you can probably borrow one from someone.

Wouldn't it be great to be able to heard these finned rats into a small creek and then put a net across it.

As for processing the the fish into fish meal, the more bones the better. This is calcium and is ideal for feeding laying hens. The liquid by product is sold over here as a liquid fertiliser.

Here is a link: http://www.charliecarp.com/news.php

BAB

Get a cheap compass and use it to see if the trolling motor generates a substantial magnetic field before investing in electromagnets. Put the compass at different points on the hull and see where the needle points when the motor is on and when it is off. Secure the boat during tests so it doesn't dtift about, changing directions and screwing with your readings. Did you say 35 HP trolling motor? If that's running off 12 volts you've got a helluva lot of current* flowing through that motor and its battery cables. That much current will create a noticeable magnetic field. Hold the compass near one of the cables and the compass should flip right perpendicular to it the *instant* the power is switched on. In place of a compass, many of the new mobiles (iPhones, et al) have built in magnetometres. Is there a compass "App For That?"

* 2173 A = (35 HP * 745 W/HP) /12 V. Almost 2200 Amps is going to create a non-trivial field, no doubt about it.

Thank you for that simple test. It makes sense.

The rating is 35 pounds of thrust. I am not sure of how they rate these things as never having owned a trolling motor.

Sorry, I misread your post (it was late, and I was fighting off zombies singlehandedly :-); 35 lbs thrust vs 35 HP is *huge* difference. Forget that part but try the compass.

netmaker, stupid question but has anyone identified the pheromone given off by the females when they are ready to spawn? I wonder if you couldn't build a chute with high vertical walls with a trap door and a conveyor on the bottom that released the scent of a spawning female asian carp into the water to attract the males. when the chute is full of horny males, close the trap door pump out the water, and crank up the conveyor and haul them into a fishmeal processing facility. granted it only gets mature males, but without mature males, the spawning should get cut way down...

Rumor only.... I was told by a guy, who heard from a guy that knows a guy....scuttle butt...... that they did ID the pherome and could re-produce.

Reality??? I have no clue. I'll be up there next month with the Danish Seine and Paupier rig. I want to ask that question myself.

It would make for an easy way to the river rats in a cleaned out section of river or oxbow and then cirlce 'em up with the Danish (purse).

Pick out the natives and bring just the bad guys to the processor.

Hi Netmaker

This device used an electric field to keep sharks at bay. It might have a similar effect on your Asian Carp.

I would make an underwater recording of both the outboard motor as well as the electric trolling motor and play it back near a school of carp to see whether it is an acoustic stimulus.

A long time ago I experimented with acoustic (sea) fishing. I tried the full range of frequencies without much success. One day I plugged the underwater speaker into the radio and ..... got some responses (I think from sharks) when the Beatles started playing. Can't remember the song - could have been "Yellow Submarine"

Thank you for the lead Maurice, I'll pass this along. Yellow submarine....... ha ha ha sounds like it makes enough noise.

I think what you are seeing here is similar to a sheep dog herding sheep, by gentle persuasion, versus a mountain lion running at the herd at full throttle.

The trolling motor is not fast enough to outrun the fish, so they merely move ahead of the boat.

The outboard, on the other hand, is much faster and louder, and puts the fish in a panic stampede mode.

I have seen other species of fish leap out of the water when a large predator is close by,even bream,perch, and crappie.

Perhaps a gentle herding could corral the fish into a net for capture.

Hello Red,

That sure looks like the pattern.Hopefully in the next weeks, they will experiment a little and determine something concrete. I have so little time to test this stuff out when I get up there, as everyone wants to put the Big Ol' nets in the water and start fishin'.

However, I've been steadily recommending the suggestions fom here to the lead researcher and he is trying to test each theory out.

One thing did occur....we found that when these Young of the Year (YOY) fish are under 8" in length they immediately school like herring or sardines when threatened. Every body is looking at chasing the Big Critters that can swim 5-8 knots for 60-90 seconds Burst Speed and maintain Cruising speed at 2-3 knots afterwards for a long time.

I am thinking it would be better to discuss a plan to concetrate on the YOY fish which will be much easier to 'herd' and encircle as all of their attributes for escape and gear avoidance will NOT be matured as yet.

thank you for the analogy.

Won't that leave you with having to repeat it every year (for some years, anyway), unless you stop the mature fish breeding?

The mature fish are being targeted by commercial fishermen on one end and are eating themselves out of food on another.

There is a thought that if you control all the YOY, there will be no recruitment of sexualy mature adults.

Sort of like limiting a duck hunt to just breaking eggs and chasing ducklings, or maybe just hunting deer with SPOTS ONLY, or maybe killing off all the calves on the range, whether you plan to eat them or not, just start killing all the calves you see.

Its one way of keeping numbers low. ( I am NOT a biologist and this idea was brought to me as a suggestion from a biologist)

Some big critters will escape and there will always be some in the eco system just not millions of them.