Musannaf Ibn Abi Shayba 13:3247

Abu Bakr narrated to us, he said: Zayd ibn al-Hubab narrated to us, from Hammad ibn Salamah, from Hajjaj, from Ata regarding the sea: [If] goods are cast [overboard], he said: It is in the status of a lost item (luqata); you make it known.