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.
تمہارے لیے دریا (کی چیزوں) کا شکار اور ان کا کھانا حلال کر دیا گیا ہے (یعنی) تمہارے اور مسافروں کے فائدے کے لیے اور جنگل (کی چیزوں) کا شکار جب تک تم احرام کی حالت میں رہو تم پر حرام ہے اور خدا سے جس کے پاس تم (سب) جمع کئے جاؤ گے ڈرتے رہو
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.