It was narrated from Jabir that:
The Prophet was asked about seawater, and he said: "Its water is a means of purification, and its dead meat is permissible." (Hasan)Another chain with similar wording. (AR)
English reference (AR): Vol. 1, Book 1, Hadith 388 (AR)
Arabic reference (AR): Book 1, Hadith 419 (AR)