For stock ponds and possibly small fisheries, cross wires stretched over ponds have proved highly effective in keeping cormorants at bay, especially in other parts of Europe. Experience from Germany indicates that, in areas of heavy predation, wires spaced at between 5m and 7.5m are effective at deterring cormorants, and they are being used at carp ponds of up to 4ha (10 acres) in size. This technique is especially useful when there are alternative feeding areas for the birds in close proximity to their roost sites. This is not a cheap option and the unsightly appearance of a wired pond is likely to make any fishery unappealing to anglers and may render it unfishable. There may also be implications for other forms of wildlife (e.g. preventing waterfowl, terns, or herons from using the water, broken fishing lines and hooks tangled in the lines, etc). This is possibly only a viable method for stock ponds.