What is the ruling on eating marine animals and plants, such as oysters, crabs, octopuses, and lobsters?

Allah has permitted hunting and eating from the sea. The Prophet, peace and blessings be upon him, said concerning the sea: "Its water is pure and its dead are lawful." Therefore, it is permissible to eat everything caught from the sea, whether alive or dead, unless it causes harm, based on the Prophet's saying, peace and blessings be upon him: "There should be neither harm nor reciprocal harm."