Question: are crabs good for the environment?
Answer: Crabs are one of the main decomposers in the marine ecosystem. In other words, they help to “clean up” the sea bottom by harvesting decomposing plant and animal matter. Many fish (e.g. halibut and dogfish), birds (e.g. great blue herons) and sea mammals (e.g. sea otters) rely on crabs for a food source.