Hmmmmm.
A new problem.
One that I've never encountered before.
How to keep turkeys out of the pond...

Well, let's see.
I would start with displays of pilgrims, turkey basters and
footballs around the pond.
The turkey would see all the stuff and have a panic attack thinking
that Thankgiving is getting close and take off.
Or
You could set up an electric fence for bulls,
turn it up REAL high. If the turkey hits the fence you'll have
dinner taken care of.
Or
Bait a humane trap with cranberry sauce. Once caught transport
the turkey to nearest supermarket, turn loose in the frozen food
aisle so it can join all its friends, collectively known as
Butterballs.

kathy :-)