cecil, any idea where to get coated wire?
Scott,
Aquatic Ecosystems has it:
Galvanized PVC coated. Oh but it's not cheap and you have to buy 100 feet. 100 feet of 1/2 by 1/2 inch four feet wide is $665.00. That does not include motor freight!
Maybe Stoney Creek sells it and they will cut some off for you? Don't even see the plastic cage material in their latest catalog although I know they sell it.
If it was me I'd go with the plastic netting. It's pretty strong stuff. It's possible otters will ignore the cage of fish. Are you sure you have them?