Verschmutzung der Ostsee durch Öleintrag erreicht Tiefpunkt
The number of oil spills in the Baltic Sea detected through daily aerial surveillance reached an all-time low again in 2015. According to the annual HELCOM report now available, also the size of spills spotted in the region continue to decline following long-term trends.
Striking is that half (49%) of all spill detections were identified as substances other than oil or as unknown observations—highlighting the ongoing need to track various kinds of spills. Nonoil-based discharges, which only have been reported to HELCOM since 2014, are not as strictly regulated as oil in the Baltic Sea and may cause threats to the marine environment. Collecting data on the frequency, size and nature of such spills is essential to understanding the environmental impacts of different kinds of substances on the Baltic Sea.
According to the HELCOM report, a total of 82 mineral oil spills were identified in the Baltic Sea by air in 2015, with the overwhelming majority (98%) limited to an area of one cubic metre (1 m3) or less. Almost three-quarters (78%) were smaller than 100 litres or 0.1 m3.
The total flight time dedicated to spill detection by the HELCOM member countries has dropped in recent years with an average of around 4,000 hours per year being logged in 2014 and 2015. This is a significant fall from the 10-year average of over 4,500 flight hours a year—a fact that may play a factor in the decreasing number of detections made.
Regional aerial surveillance continues to be vital to detecting oil spills and other potentially harmful substances released into the Baltic Sea. It also acts as a deterrent to ships, thus preventing violations to regulations on ship pollution. When a spill is discovered, if possible, the identity of a polluter is established and the spill is sampled from both the sea surface and on-board the suspected offending ship to enable prosecution.
In addition to regular, nationally led flights, high-intensity operations are organized on a yearly basis to bolster compliance levels to anti-pollution regulations. During such operations a selected area is continuously surveyed together by a number of countries up to several days.