It wasnarrated from Jabir bin 'Abdullah that the Messenger of Allah(ﷺ)said:
"Whatever the sea throws out or is left behind when thetideebbs, eat it, but whatever rises to its surface, do not eat it.'" (TH)
English reference (TH): Vol. 4, Book 28, Hadith 3247 (TH)
Arabic reference (TH): Book 28, Hadith 3370 (TH)