I would like to find a selection of natural poisons that are easily found in the UK that can be used to incapacitate fish but have no effect on the human physiology. Could someone please list me some.
Retenone - removes the oxygen from the water suffocating the fish which then must be quickly removed to prevent the ultimate stink as they rot away. A monumental task involving a LOT of manpower and boat power to spread the chemical and then to remove the resulting dead and dying fish. I don't recommend it. Also, some fish revive and survive which may require a second treatment. Depending on the size of the body of water, this can be a VERY spendy endeavor.