One problem with people is that they hear different messages in their own mind when told the same thing. I think Lusk has a good idea to tell people that the biologist does not want people fishing the pond, but many of those would-be anglers may interpret that as "Well, they must be concerned about other species getting into the pond, so it must be OK to fish with artificial lures, just not live bait, and because I catch and release everything, I can fish there." WRONG ANSWER!
I've found that the best, most clearly interpreted message is to simply say "NO" or "no, it's private."
Leave no room for interpretation.
At our lake, we had people come by and say "you just bought the property and now we can't fish or hunt here, and we've been fishing and hunting here all our lives."
I just tell them that they should have bought the property when it was for sale.
We tried the nice approach with unsatisfactory results. Now we just stearnly say NO.
