Marine pollution is the harmful effect cause by the entry into the ocean of chemicals or particles. An associated problem is that many potentially toxic chemical's adhere to tiny particles which are then taken up by plankton and benthos animals, most of which are either deposit or filter feeders, concentrating upward within ocean foodchains. Also, because most animal feeds contain high fish meal and fish oil content, toxins can be found a few weeks later in commonly consumed food items derived from livestock and animal husbandry such as meat, eggs, milk, butter and margarine.