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. (IT)
English reference (IT): Vol. 1, Book 1, Hadith 388 (IT)
Arabic reference (IT): Book 1, Hadith 419 (IT)