Islam encourages Muslims to consume what is lawful and pure. According to the majority of scholars, seafood, including crabs, whales, crawfish, and other sea creatures are lawful to eat. When the Prophet (peace and blessings be upon him) was asked about the sea, he replied, “Its water is pure and its dead arehalal.” (Ahmad)
It is also reported, on the authority of Jabir, that the Prophet (peace and blessings be upon him) once sent some of his Companions on an expedition. They found a dead whale by the sea and subsisted on it for more than twenty days. On their return to Madinah, they told the Prophet (peace and blessings be upon him) about this and he said, “Eat the food which Allah has brought forth for you and feed us from it if you have any left.” They then brought him some whale meat and he ate it (Al-Bukhari).
Elaborating on the Islamic ruling of eating sea food including sea animals, Sheikh M. S. Al-Munajjid, a prominent Saudi Muslim lecturer and author, states: “Among the blessings that Allah has bestowed upon us is the fact that He has made our religion easy for us, and has not made it too difficult or unbearable. He has allowed us many things that were forbidden according to previously-revealed laws. Allah says: “… Allah intends for you ease, and He does not want to make things difficult for you…” (Al-Baqarah 2:185).
Hence all kinds of food from the sea are permissible, whether they are plants or animals, alive or dead. Allah says: “Lawful to you is (the pursuit of) water-game and its use for food – for the benefit of yourselves and those who travel…” (Al-Maa’idah 5:96). Ibn `Abbas said: “Sayduhu (i.e. hunting, pursuit) refers to whatever is taken from it alive, and ta’aamuhu (i.e. its food) means whatever is taken dead.”
There are a few things – certain types of water animals – which some scholars exclude from the permission outlined above. These are:
Crocodiles. The correct view is that eating these is not allowed, because they have fangs and live on land – even though they may spend a lot of time in the water – so precedence should be given to the reason for forbidding it (it is a land animal that has fangs).
Frogs. It is not permitted to eat them because the Prophet (peace and blessings be upon him) forbade killing them, as is reported in the hadith of ‘Abd al-Rahmaan ibn ‘Uthman, who said that the Messenger of Allah (peace and blessings be upon him) forbade the killing of frogs. (Narrated by Imaam Ahmad and Ibn Maajah). The rule is that everything which we are forbidden to kill, we are not allowed to eat; if we are allowed to eat it we are allowed to kill it.
Some scholars exclude sea snakes, but the correct view is that as they live nowhere except in the water, we are permitted to eat them, because of the general nature of the aayah: “Lawful to you is (the pursuit of) water-game and its use for food – for the benefit of yourselves …” (Al-Ma’idah 5:96).
Otters and turtles. The correct view is that to be on the safe side, it is permissible to eat them after slaughtering them properly, because they live both on land and in the sea. Here the rule is that in the case of animals that live both on land and in the sea, the rules concerning land animals should be given precedence, to be on the safe side, so they must be slaughtered properly, except for crabs which do not need to be slaughtered, even though they live both on land and in the sea, because they do not have blood.
Everything that can cause harm is forbidden as food, even if it comes from the sea, because Allah says: “… And do not kill yourselves (nor kill one another). Surely, Allah is Most Merciful to you.” (Al-Nisaa’ 4:29) and: “… and do not throw yourselves into destruction…” (Al-Baqarah 2:195).”
Moreover, Dr. Muzammil Siddiqi, president of the Fiqh Council ofNorth America , adds:
“In the Qur’an, Allah Almighty says, “Lawful to you is (the pursuit of) water game and its use for food – for the benefit of yourselves and those who travel, but forbidden is (the pursuit of) land game as long as you are in a state of Ihram (for Hajj or ‘Umrah). And fear Allah to whom you shall be gathered back” (Al-Ma’idah 5:96).
Some jurists interpret the word “ta’amuhu” (meaning food that comes from the water) as being fish only. But other jurists take it to mean anything that lives in the water and is edible. The latter is the majority opinion, and it is closer to the language of the Qur’an. I am inclined to take the majority opinion. Majority of the jurists consider shrimps, shark, whale, and all other types of seafood permissible to eat.”