This winter two goldfish were released into the pond to see if the water was habitable for fish. Just this week, the two experimental carp resurfaced, demonstrating enough support for fish life in our waters here on Leafhopper Farm. Carp are a very hardy family in the fish network, able to live in all manner of aquatic habitat (hence their invasive status in most American waters). Few people realize that both goldfish and the decorative Koi are both members of the carp family.
Our pond is contained, so these friendly fish folks won’t be getting out into the wilder waters of the Snoqualmie River or its tributaries. Please note that your pet goldfish, if released into wild waters, will breed back into its old carp form in time, producing the large invasive predator fish that are overtaking our native lakes and rivers. Koi are the same way, in time breeding back to their less colorful form. Our pond will need to be managed to prevent a carp takeover by hunting and eating the offspring of these decorative samples of domestication.
It is so wonderful to be releasing fish into our pond in year two of our earthworks development. The waters have sustained themselves with ground catchment and do not dry up, even in harsh drought conditions, so we’re trying out our first round of fish to see if the addition of a predator will keep the bug populations in check. Blue Darner Dragonflies have come out of their water nymph forms and the tadpoles still developing in the water at this time are bullfrogs. Native frogs bred and lay their eggs earlier on in the spring before larger invasive frogs come to breed.
We added some smaller gold fish to tempt the herons away from the bigger, more costly Koi. Hopefully the cedar stump creates enough refuge, along with a still very deep center pool in the pond design to protect the fish against arial assault and the wily hands of the occasional raccoon. If the fish survive, they will be mature enough to breed in seven years. By then, the pond will be holding its maximum capacity of water, and fishing for the carp can begin to keep numbers in check. The colorful Koi add an esthetic sense to the water feature and ensure a more natural balance of predator and prey relationship in our aquatic habitat.
Why not native fish? Well, to stock your pond with natives, you must go through the state and pay an annual stocking fee. Since this aquatic home is man made, and not in use as a fish farm, we chose to enjoy decorative fish with a future plan of harvesting the carp. Native trout would also need more space, greater aeration, and are highly managed by the state if introduced to any water system. Koi are considered a hobby fish, and in our closed pond, there is no risk of contaminating wild waters with the highly invasive carp. We look forward to enjoying these beautiful fish for many years, as Koi have an impressive lifespan if cared for properly. In future, once the pond is holding maximum water, we’ll install an aerator for the health of the water, fish, and other species that thrive in an aquatic world.