I've had a pond for twenty yrs. Several ups and downs but I enjoy it immensely. My question involves how to protect my fish in the winter when the lilies die back and they have no cover. In the last month I've scared off a big egret two times that was hellbent on having a koi lunch. We've also had blue herons pay visits. Our pond is about 3 1/2 ft. deep but these birds have long necks. I've checked with local pond stores about large fake water lilies or something similar to give the fish a little cover, but they can't find anything. Right now I'm thinking of putting bubble wrap on top, but would like to find something more attractive. Any ideas?