TM males are always sterile, females are generally fertile and will backcross with either parental species, particularly NP.
The conditions your pond shows with the flooding of vegetation such as that is similar to a lake in PA where they drained it down several feet for dam repairs. It was down for about 4 years allowing vegetation to grow in the area usually covered when at normal pool. When the repair was finished and the lake filled back up, the pike had an incredible spawn producing an amazing couple of years classes.
