Pretty sick Baltic Sea

Patient: The Baltic Sea, age 3500 years
Epicrisis (medical case summary): The patient has been suffering from symptoms of eutrophication since the mid 1900´s, transformed from a nutrient-poor, clear state to the current murkier, nutrient-rich state. Suffering also from loads of harmful substances, such as heavy metals, but less than earlier. Some deformations observed in the biological communities due to foreign intruding species and human disturbances. The patient has been treated with reduction in the nutrient load from agriculture and waste waters and restrictions in the use of harmful substances.
Diagnosis: Chronically eutrophicated, moderately polluted by harmful substances, severely disturbed by human acitivities
Further treatment: continued reduction in the nutrient loads, binding multinational agreements on the protection of the sea, heavy control on the invasive species.

The health of the Baltic Sea is a general concern. The most alarming issue is eutrophication, but alien species, freighting of oil and chemicals present serious threats to the sea as well.

The concern is justified: HELCOM Holistic Assessment shows red for the current health status. Only some corners in the north and west are considered to be relatively healthy. The Baltic Sea has been a candidate for the most polluted sea in the world.

True or not, the state of the sea is far from a natural, healthy state.

Eutrophication

Massive algal blooms speak for themselves: The Baltic Sea is severely eutrophicated. Eutrophication means an overgrowth of algae and a lush shore vegetation, caused by excessive amounts of nutrients in the sea. More production means also murkier water. The visibility depth of the Baltic Sea has been significantly reduced during the last hundred years.

More green production - what´s the problem? Marine life can be suffocated by eutrophication. Some submerged plants, such as bladderwrack, suffers from the nutrient-rich, turbid water. Moreover, the massive green production may cause severe oxygen depletion in the sea bottom, as the organic material consumes oxygen when decomposed. This in turn, may kill the life in the deep totally.

Light in the tunnel: decrease in the amounts of harmful substances

The history of some pesticides shows the strength of joint efforts. The amounts of some toxic substances, such as heavy metals and DDTs, have decreased in the Baltic Sea marine environment.

The decreased amounts of harmful substances have reflected to the recovery of some marine animals, like the white-tailed eagle – a true success story of nature protection.

Aliens in the Baltic Sea!

Due to the peculiar conditions (brackish water, geologically young) there are few species in the Baltic Sea. Low biodiversity means vulnerability to human disturbances. Overfishing and eutrophication can be claimed to be the major factors affecting the biological communities.

Besides overfishing and eutrophication, invasive, or alien species, may interfere the native fauna and flora. They may be called as “biopollution”. Some of these “aliens” travel in ballast waters of boats.

The Baltic Sea seems to be a really a Sea of Problems. Is the state hopeless? Not at all. It´s time to leave the doomsday´s predictions and concentrate on problem solving.

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