I live in a bayside suburb of Melbourne along with 3.5 million...

I live in a bayside suburb of Melbourne along with 3.5 million possums, they have just about killed my 40 y/o apple tree which supplied the neighbours up until a couple of years ago with more apples than they could use, if something is not done this season will be it’s last.
Last year I had to pay to remove a 20ft tall Photina that they killed and the lemon tree was under attack a couple of months back (there were all these nude lemons under the tree).
What to do? Shooting is not an option as 1 or 2 neighbours are animal lovers (even cats). Trapping and relocating? legally only allowed to move them 50 Mts. (I think). Poison? 1080 is very difficult to get, anything else work?
I am looking for practical suggestions.
Now if it was NZ !