Admittedly, not everyone with a backyard pond is in need of a heron deterrent. The beautiful blue bird may even be a welcome sight, until you decide to stock your pond with goldfish, koi, or another fish of your choice. The heron isn’t known to be particularly fussy about which kind. To a heron, “fish is fish”.It isn’t just private pond owners that feel a need to find a heron deterrent of one type or another. Some years back, in a Seattle marina, the fisheries department had an enclosure immersed in the salt water, which contained a large number of salmon fingerlings. The size of this enclosure was approximately 6′ by 6′, with the sides sticking up about 6 inches above the surface of the water. A blue heron took up residence one day and contented itself by gorging on the little salmon.