On 25 April this year, and the previous week, the sea became red. They don't know why, but they think it was from the "iron rich clay" which suddenly caused the effect.
Meanwhile I'll just go with this explanation:
Every time Nibiru crosses in front of the Earth, it plants our entire planet (land and seas) with millions of tons of fine red dust of Iron Oxide. As time goes by, the Iron Oxide builds up sediment, and this is covered over by new layers of sedimentation that has been deposited on top. And these days, the ground in many parts has moved. It is possible that the movement of the ground left a cloak of Iron Oxide exposed, that would have come in contact with water and been dragged away.