Baltic fish less contaminated than 25 years ago

HELSINKI, Finland, January 4, 2005 (ENS): There is good news for people who eat fish from the Baltic Sea - they are less contaminated now than they were 25 years ago. Concentrations of lead and polychlorinated biphenyls (PCBs) in Baltic Sea fish have declined during the last 25 years, according to a new study issued Monday by the Helsinki Commission.

The Helsinki Commission, or HELCOM, works to protect the marine environment of the Baltic Sea from all sources of pollution through intergovernmental co-operation between the countries bordering the sea - Denmark, Estonia, the European Community, Finland, Germany, Latvia, Lithuania, Poland, Russia and Sweden.

HELCOM is the governing body of the "Convention on the Protection of the Marine Environment of the Baltic Sea Area," more usually known as the Helsinki Convention.

The decrease of contaminants in the Baltic Sea fish is a result of measures taken by the HELCOM countries to reduce discharges of lead and PCBs to the environment, the Commission said when launching the report.

The Baltic Sea, as one of the world’s largest bodies of brackish water, is ecologically unique. Due to its special geographical, climatological, and oceanographic characteristics, the Baltic Sea is highly sensitive to the environmental impacts of human activities in its catchment area, which is about four times larger than the sea area itself and is inhabtied by some 85 million people.

The comprehensive monitoring program coordinated by HELCOM assesses the whole pathway of hazardous substances - from emissions on land to their effects in the marine environment, including fish.

"This information allows for appropriate decisions to be made in order to reduce pollution," the Commission said.

As a result, annual emissions of heavy metals to the air have decreased since 1990 and consequently their annual deposition onto the Baltic Sea has been halved during that time, HELCOM said.

The study found that lead concentrations in liver tissues of fish commonly eaten by humans, such as herring, cod, and perch, show "coherent trends of similar magnitudes in various regions of the Baltic Sea."

Sampling, sample preparation, storage in specimen bank and evaluation of results were carried out by the Contaminant Research Group at the Swedish Museum of Natural History, Stockholm. Chemical analysis was carried out at Institute of Applied Environmental Research at Stockholm University.

They have documented that since 1981 the concentrations of lead in herring and cod liver have been decreasing at an average rate of four to seven percent per year, and more recently in perch liver up to a rate of 13 percent.

The Helsinki Commission has imposed bans and restrictions on the production and marketing of PCBs since the 1980s and called for measures to decontaminate PCB containing equipment and dispose of PCBs in an environmentally sound manner. The Commission's goal is to completely cease the input of these hazardous substances to the Baltic Sea by the year 2020.

As a result of these bans and restrictions, PCB concentrations in herring muscle have shown significant decreasing trends during the last 25 years. The rates of decrease have varied between four and 10 percent a year, indicating a total decrease of 60 to 80 percent since the end of the 1970s.

PCB concentrations in cod and perch also have been decreasing, with an average annual rate of decrease of six to 10 percent since 1980.

Still, despite obvious progress in the reduction of discharges of lead and PCBs to the environment, their concentrations in the sea water are still several times higher in the Baltic Sea compared to waters of the North Atlantic.

Concentrations of PCBs and lead are three to six times higher in the Baltic Proper and in the southern Bothnian Sea even compared to the Kattegatt and the Skagerrak areas, HELCOM said.

In general, the concentrations of heavy metals and organic pollutants in sea water are several times higher in the Baltic Sea compared to waters of the North Atlantic.

Continued eutrophication and persistent pollutants in living organisms are the main concerns underlined in a set of new and updated HELCOM environmental indicators launched by the Helsinki Commission Monitoring and Assessment Group in December 2004.

The regional extent of eutrophication is clear from concentrations of nutrients in winter and the subsequent intensity of spring phytoplankton blooms. Toxic blooms of blue-green algae, or cyanobacteria, continue to be extensive in the Baltic Sea, the monitoring group warned.

The amount of radioactive caesium-137 in the Baltic Sea from the 1986 Chernobyl explosion and fire remains unchanged, with highest concentrations in the sediments of the Bothnian Sea and the Gulf of Finland.

Even though an increase in maritime transportation across the Baltic during the past decade has increased the potential for illegal oil discharges, the number of observed illegal oil discharges has been decreasing every year. Still, some 300 illegal oil spills were detected in 2003.

The Baltic Sea catchment area extends over some 1.7 million square kilometers and is home to nearly 85 million people.

There are 11 cities with populations greater than 500,000 citizens in the catchment area, and almost 15 million people live within 10 kilometers of the coastline.

View the new Baltic Sea indicators online at: http://helcom.navigo.fi/environment/indicators2004/en_GB/indicators2004/