It is known that 70% of the Earth's surface is made up of seas and oceans, and one of the most latest topics in the last few years is the pollution of the aquatic environment. A big amount of harmful substances in the sea comes from the land. The massive number of industries, the more frequent use of pesticides in agriculture, the use of various vessels, all types of urban waste, etc., cause marine pollution. The most endangered is the seacoste where biological, chemical and physical contaminants affect the seawater and all the marine organisms of the area. After harvesting, a large number of organisms are consumed as human food. An example are shellfish, which are mostly consumed raw or slightly cooked, and it is especially important to take into account their microbiological safety. The aim of this bachelor thesis is to describe the process of depuration and its significance with the public health. The thesis describe all biological, chemical and physical substances that have negative consequences on public health. The process of depuration is explained as well as the importance of monitoring the parameters that effect the rate of depuration and some of the most important regulations is preventing foodborne disease.