A fish trap is a great tool in a survival situation.
With fast weaving you too can have a fish trap in a pinch. Witness how to make a fish trap with Survival Lilly.
With reeds, grasses or sticks one can weave together a fish trap that just may catch your dinner if lost in the wilds. The fish swim in and then get confused. They usually will not back out and a trapped fish will be there when you return. Well that is the plan at least as long as the fish are willing.