Get in touch with the Environment Agency, ask for the local area rivers/fisheries officer and ask them if they know anywhere where they have found Zander. They carry out periodic electro-fishing of the rivers and usually find some. They will give you details of locations and also ask if there are any deep spots where they cannot reach and that's your likely hot spot. So ask there first. Now if you want to copy the so called predator experts in the mags and sit with a legered dead bait you might aswell watch paint dry. Get some live minnows and trot them down about 12" off teh bottom on 6lb line and a 3gram avon type float no wire trace single 10 treble and you can empty the river! The EA state that they should not be returned to the water because they are an alien species. good luck let me know how you get on. NOTE Tranferring fish without EA licence is an offence.