Yes. Sea animals are lawful even when found dead, because the Quran permits the game of the sea and its food (5:96). Scholars also permit locusts, based on the hadith that two kinds of dead animals are lawful: fish and locusts.
Lawful to you is game from the sea and its food as provision for you and the travelers, but forbidden to you is game from the land as long as you are in the state of ihram. And fear Allah to whom you will be gathered.
This is general information, not a fatwa. For your own situation, ask a qualified scholar.
Questions about halal and haram
Can I eat fish that died by itself?
Yes. Sea animals are lawful even when found dead, because the Quran permits the game of the sea and its food (5:96). Scholars also permit locusts, based on the hadith that two kinds of dead animals are lawful: fish and locusts.