Behind the aforementioned pergola we have a pond 8ft.sq., for the last 15years we have kept gold fish which seem to have thrived. Last year, over night, all the fish vanished and we thought we had been visited by a heron. after investing in a new mesh cover we placed it over the pond weighed down round the edges by stones and new fish we bought! Two or three days later they were gone,the mesh was still in place slightly raised in one place, and we discovered that there are otters in area. Now the dilemma, do we invest in a stainless steel grill or put our hands up and turn the so calling fishpond into a wild life pond. I don't want to keep providing breakfast for the otters. Any opinions out there. Finty