Koi Disappears from 60-Gallon Pond: Predators or Jump?

One Koi Gone from a Small Pond—What Happened?

A 60-gallon pond with three koi over a year old suddenly has one missing. In a volume this small, the list of culprits is short but the risk is high.

Likely Scenarios

• Predation: Raccoons, herons, cats, or even large birds can take a koi from a 60-gal pond—especially if it's shallow or lacks cover. A 60-gal pond is typically 2–3 ft wide; a heron can stand in it.
• Jumping: Koi jump when stressed, spawning, or if water quality drops. Check around the pond perimeter, in plants, under decks, and in filter boxes.
• Decomposition: If the fish died and sank, it may be hidden in debris or eaten by snails/insects quickly in warm water.

Immediate Steps

1. Measure the missing koi's size—larger fish point to herons; smaller to raccoons/cats.
2. Inspect pond edges for tracks, disturbed plants, or scales.
3. Check filtration system—sometimes fish swim into skimmers or pump intakes.
4. Test water quality: ammonia/nitrite spikes can cause erratic behavior and death.

Prevention for Small Ponds

• Install rigid netting or a floating frame cover.
• Add a motion-activated sprinkler (e.g., ScareCrow).
• Provide a submerged cave or PVC pipe for refuge.
• Ensure pond edges are vertical or overhung to deter wading birds.

In 60 gallons, every fish is visible daily. A disappearance demands immediate investigation—small ponds offer little margin for error.