Electrozapping fish

[spindle]

Casually watching from my narrowboat the local angling club electro-stunning pike presumably to remove them from the canal, I enquired as to what power was being used and was somewhat surprised with the answer 10A at 110V in very close proximity to my boat. It crossed my mind as to what effect, if any, this would have on my galvanic isolator.

[Smelly]

Never mind your isolator, what about the bleedin Pike?

[alan_fincher]

I enquired as to what power was being used and was somewhat surprised with the answer 10A at 110V in very close proximity to my boat.

I know nowt about electro-zapping, but for 10 amps to flow at just 110 volts, there has to be a resistance of just 11 ohms across the supply voltage. Where is that 11 ohms coming from, as clearly neither electrodes separated by fresh water, nor even a fish, presents such a low resistance. I think the story you have been given may be less than accurate, but I'm not sure......

[estwdjhn]

I know nowt about electro-zapping, but for 10 amps to flow at just 110 volts, there has to be a resistance of just 11 ohms across the supply voltage. Where is that 11 ohms coming from, as clearly neither electrodes separated by fresh water, nor even a fish, presents such a low resistance. I think the story you have been given may be less than accurate, but I'm not sure......

 

I suspect that the device in use is powered from a 110v supply.

 

I imagine that the voltage applyed to the fish is upped somewhat.

[fuzzyduck]

So the fish come pre cooked, cool!

[Justme]

Check this out

[fuzzyduck]

Later the fish - some with burn marks - died.

 

So they do come precooked.

[DameEdna]

Casually watching from my narrowboat the local angling club electro-stunning pike presumably to remove them from the canal, I enquired as to what power was being used and was somewhat surprised with the answer 10A at 110V in very close proximity to my boat. It crossed my mind as to what effect, if any, this would have on my galvanic isolator.

 

 

Not a lot unless your shore-power cable is connected to ground in which case the isolator will detect the current and turn on which in turn will trip the RCD and disconnect the onshore power from your boat.

 

I wouldn't stand astride the gap between boat and bank with one foot on the steel deck and one in the wet grass either

[John Orentas]

Check this out

 

 

Yes it is quite wrong to catch fish in this way.

 

I used to work with a chap who served in Korea, he said that by far the most effective way is to chuck a hand-grenade in the water "You get as many fish as you can eat".

[carlt]

This method is used regularly, to remove zander, from the cut

 

It doesn't work, though, they've been doing it for years and the zander are still here.

[Justme]

I think they work on the same principle as electric stunners used before killing animals. Its all to do with the frequency.

 

Justme

[chris w]

No the equipment may work off 110v and be capable of delivering 10A through a suitable impedance, but they will be upping the voltage to a high level to stun the fish and the current will be miniscule. I wonder how they are able to just select pike

 

It's a sobering thought though that the human heart can go into fibrillation on as little as 5 milliamps (ie: 0.005 amps!). Think of that next time your 30 milliamp RCD blows. It's the reason that the US use 5mA RCD's on protected domestic sockets.

 

Chris

[carlt]

I wonder how they are able to just select pike

The Braunston Zander zappers electrocute everything but only the Zander get scooped up, to drown , in the dinghy.

[Guest TerryL]

I wonder how they are able to just select pike

They use an earth spike.

[tinca steve]

WHOA THERE Water authorities have used Electrofishing techniques for many years to no ill affect. I believe its a very small shock that stuns fish so that they float to the surface for just a few seconds then recover very quickly, WHEN it is done correctly.

 

Also Zander are an introduced species that need to be culled.

Edited November 4, 2008 by tinca steve

[carlt]

WHOA THERE Water authorities have used Electrofishing techniques for many years to no ill affect.

True, I've never seen dead fish, as a result of the zander zappers.

 

Also Zander are an introduced species that need to be culled.

Culling Zander doesn't affect the population, they just weed out the slowest to recover from a zapping.

 

Waters that are not controlled have seen the zander establish itself, but in no greater numbers than where culling takes place. and balance is eventually restored.

 

Electrofishing is, arguably, encouraging the leaner, fitter fish to flourish.

[tinca steve]

Smoked Zander is also very nice .

[GSer]

I've done a fair bit of electro fishing/survey work in the past, and i've never seen a fish harmed by the stunning itself, much more damage is done to the fish by clumsy handling IMO. Handling damage can be kept to the very minimum by use of unhooking mats and padded interiors of the boat and its equipment.

 

Big pike fetch good money, but I doubt that would have been the intention of that fishery manager from Oxford

 

Paul

[carlt]

Smoked Zander is also very nice .

I haven't tried it smoked but the electrofishers always left me a few and baked, stuffed with herbs and half a lemon, worked for me.

 

I've got a smoker, now (since getting the lifeboat, the freezer is overrun with seafish) but I've lost my Zander source.

[tinca steve]

If your vessel has a wood burning stove/ heater then you have a smoker . Check out H.F. Whittingstall.

[John Orentas]

I know it keeps coming up and the louder people think they know all about it but there are so many variables in this electrocution in water business.. Does the James Bond trick of dropping an electric fire into your spouses bath really work, I am not sure that it would..

 

Electrocution of course depends on attaining a sufficient voltage differential between the head and the feet.. So larger creatures are far more vulnerable than small ones, so many times I have heard "It's the amps that kills you, not the volts" that very hackneyed sentence makes very little sense either.

 

So in theory, pass a current through a pool in Africa and you will get a few dead Alligators and thousands of tiddlers will be unaffected ? anyway pure water is a good insulator so how grimy has the water got to be.

Edited November 4, 2008 by John Orentas

[alan_fincher]

Does the James Bond trick of dropping an electric fire into your spouses bath really work, I am not sure that it would..

Oh was that James Bond ? ......

 

I thought it was James Blunt !

 

(Sorry John! )

[ditchcrawler]

True, I've never seen dead fish, as a result of the zander zappers.

 

 

Culling Zander doesn't affect the population, they just weed out the slowest to recover from a zapping.

 

Waters that are not controlled have seen the zander establish itself, but in no greater numbers than where culling takes place. and balance is eventually restored.

 

Electrofishing is, arguably, encouraging the leaner, fitter fish to flourish.

That last line sounds like the argument made to retain fox hunting

[carlt]

That last line sounds like the argument made to retain fox hunting

When the hunt believes it is an effective means of culling?

[ditchcrawler]

Casually watching from my narrowboat the local angling club electro-stunning pike presumably to remove them from the canal, I enquired as to what power was being used and was somewhat surprised with the answer 10A at 110V in very close proximity to my boat. It crossed my mind as to what effect, if any, this would have on my galvanic isolator.

A bit about it here http://en.wikipedia.org/wiki/Electrofishing