Were there any circumstances that influenced the survey?
Winter's high tide and storms have brought extreme amounts of litter on the beach. A large pile of seaweed with lots of litter has been gathered high up on the beach. We calculated the volume of the pile along the distance to 150 cubic meters. The measurement is probably a large underestimation of the amount of litter.
Were there any events that lead to unusual types and/or amounts of litter?