Keepers of koi appreciate their unmatched beauty and contribution to the larger ecosystem of a pond. Commitment to care is required with koi; fragility of life, well recognized. Nature, in all its brilliance, provides clear clues when conditions are amiss and life is threatened. It gives us a chance to rectify the situation and right a potential disaster. Koi are sensitive fish and seek stability in their environment. The best caretakers ensure a consistent ecosystem and are rewarded with fish that serve as a connective thread between man and nature.
Working off of a short list of typical causes, a stressed koi can be identified in short time but the root cause may be difficult to pin down. They range from water quality to parasites to predators, or a mix of all.
Perhaps the most obvious indicator of stress is change in the koi’s appearance. Their orange, copper and buttery glossed goodness will fade to a dull matte. And damage to scales or fins that might attract predators will surely induce anxiety. Parasites, such as tapeworms, can bring about a physical change but are easily treated. As a preventative measure, many koi owners choose to regularly treat fish for infections - before problems arise. A general treatment will address a wide range of potential issues, but a healthy and well-balanced ecosystem is considered the best prevention. Good aeration and clean water, with an OASE filter and pump, could make the difference.
As with humans, fear and stress go hand-in-hand. While a new home with a healthy ecosystem might offer a fresh beginning, koi will require time to relax. They will seek shelter while becoming acclimated to the new ecosystem. But koi will only settle properly if the pond boasts good water quality, so ensure the pond is cycled correctly prior to arrival of the fish - or risk harming or killing the koi. Fish are responsive to sudden changes in water quality and other aspects of their environment. Imbalanced ammonia and pH are typical offenders, but not always.
And, of course, there are the predators. The domesticated sort - the family cat or dog, for example, enjoys the game of cat and mouse and expects to win. The powerful hawk and nimble blue heron may be awe-inspiring for a homeowner but terrifying for koi. Deter predators with decoys, fountain displays, or netting. Undeterred predators will force koi to the most remote spot of the pond where they will remain hidden until the threat is removed. Give koi space to hide, under lily pads or other plants while rebuilding confidence. They will re-emerge when ready.
Science has proven the connection between Koi stress and their health. If we commit to raising koi, we are responsible for their physical and psychological health. If we don’t address one, the other is surely to become an issue.