During any survival situation, your time and resources will be limited. In order to survive, you'll have to make the most of what you have and diversify your survival food portfolio. That means learning all you can about hunting, fishing, foraging for wild edibles, and other food-gathering techniques. If one of these methods fails, you'll have plenty of others to fall back on.
With this goal in mind, here's another great way to collect food in the wild: hand line crabbing. This technique has been used for thousands of years across various cultures, and only requires a few basic resources:
Once you have those items, you can catch blue crabs easily near the edge of a body of salt water, such as a pier, beach, or jetty. It's worth noting that you'll need a license to do this legally in most places, but if you're in a life-and-death scenario, you'll have to do what you need to survive.
Here's a video that shows how it's done:
It's really that simple—just be patient, use as many lines as you can, and combine this method with other hunting and fishing techniques to provide a sustainable food source for survival. Obviously, be sure to cook your crab thoroughly and follow other food safety rules before consuming your catch.