They are in the same taxonomic class as shrimp and lobster. Bit of work collecting them but if you really are hungry and there is a will then there is a way 
. They are said to be a great source of protein, and they have a unique, savory flavor. It is said that isopods can be cooked in a variety of ways, such as deep frying, sautéing, boiling, and steaming. You can also mix cooked isopods with vegetables and other ingredients to create a delicious, protein-packed meal.
I have not tried, or should I say have not been hungry enough to try them yet. I’m more the bayou la batre shrimp type person if wanting to nibble on something from the water distantly related to the insects. While there remains debate on many aspects of the phylogeny, including which crustaceans are most closely related to insects, there now seems to be a consensus that insects evolved from crustacean ancestors. Think about that next time you munch on a lobster, shrimp or crab 
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https://eattheplanet.org/land-shrimp-a-small-relative-of-our-favorite-seafood/