Fish Traps

A fish trap is a box or funnel of wire, mesh or screen set where fish have to pass - at a pond's inlet or outlet, or in a channel joining two waters. Nothing drives the fish in; it holds whatever swims in, so it must sit where they already gather. It does two different jobs. One is taking fish to eat: removing the largest thins a crowded pond, leaving more room and more natural food for the rest, which is what stops it stunting, where too many fish share too little food and none reach a useful size. The other is catching young fish moving on high water to stock a second pond.

Two things decide whether a trap is a good idea, and neither is the trap. The first is the law. Catching and moving live fish is commonly regulated wherever a pond connects to a stream or other public water, and a permit is usually needed before a trap is set - one of the few things worth settling before building rather than after. The second is what arrives with the catch. Stocking from an unrelated water body can bring in a species or a parasite nobody wanted, and undoing that can mean draining and clearing the whole pond. The self-stocking use is sound where the source and the pond are already one system, and risky where they are not.

A set trap has to be checked daily. The catch is alive in a small volume of water, and in warm weather a trap left over a weekend is not a harvest but a fish kill. Work early while it is cool, keep the fish in clean water and move them on quickly. Turtles and other creatures that were never the target need a way out or someone to release them. A trap does not make fish grow, either: on a new pond there is nothing worth catching for two or three years while the stock reaches a useful size. A movable mesh trap left in mud is a wear item needing repair and dry storage; a concrete basin at a pond's drain needs little of that and lasts far longer.