fishing with plant poison

[Tarrel]

Or, for a more sustainable alternative, there's always Electrofishing!

We went out the other week with a guy from SEPA (Scottish Environmental Protection Agency), who demonstrated the technique. They use it for auditing fish stocks in rivers.

Basically, the guy had a Backpack on, which contained a car battery and an inverter to push the voltage up to, IIRC, 400V. One lead was connected to a kind of lance with a metal ring on the end (maybe 20 cm dia.), the other was connected to a braided cable which dragged in the water. He was wearing heavy duty waders and got in the water. He immersed the lance in the water and they just came to it.

What looked like a completely empty gravel stream bed was soon teeming with eels, trout, small salmon - all sorts. He just scooped them out to count them before returning them.

Apparently the method works by causing the fish's spine to go into spasm, first one way, then the other. They literally find themselves swimming towards the lance. (Imagine a tractor-beam on a sci-fi space ship and you'll get the general idea). The fish are not harmed. In fact, they're not even stunned. If you were doing this in order to catch fish for food, you could take what you need and leave the rest to reproduce for another day.

It's illegal, by the way, but in a post-SHTF scenario, who knows??