Lots of great ideas; my $0.02. I have a serious electric fence; it does not keep out cats,racoons, armadillos, etc; coons may cross in the trees, others mostly go under. There are alway branchs falling on it , brush growing into it and draining some power (I have to "walk the line" every week). And deer running through it when it zings them.
However, I have lost many, many more fish to snakes than other perdators ( my yard is too wooded for air attack). How do you control snakes? I like the shotgun, but I think it would damage the liner .