These consequences do not only reduce the bathing water quality and are a nuisance but they might also be harmful, especially to bathing small childs. This affects the local tourism. Eutrophication especially occurs in coastal waters near the shore where a large amount of nutrients are transported by rivers. Blooms of phytoplankton have become a recurrent problem in the Baltic Sea. As mentioned above an exceeded amount of nutrients discharged to the water leads to eutrophication.
Agriculture is one of the major sources.
Especially in proximity to the sea so that animal excretion can easily and directly reach the water without getting filtered. As seen in the picture a paddock is reaching directly to the Oder Lagoon. Cows prefer to stand in the water during summer so they can get cooling. This goes along with the fact that the major part of their excrements go directly into the water, which amounts to approximately 20 kg per cow per day. It often results in a dangerous increase of the concentration of E.Coli bacteria what can lead to a ban of bathing.