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. And it also enhances eutrophication. Tourists on the Beach of Usedom, August 1999 Tourism Actually tourism itself is not really harmful to coastal waters. The problem is more to be seen in the number of tourists.