On 25th June repeated imagery of the monitoring area was undertaken (the interval between two shots was 13 hours). The slick was detected once again.

On 27th June under conditions of the storm the slick was not detected. Analysis of available satellite images from the library of the European Space Agency (ESA) and low resolution optical data enabled to determine that for the first time the pollution caused by the ship was detected on the image in the evening of 23rd June 2011. It was found on the optical images on 24th and 25th June. This means that the slick existed on the sea surface for more than two days, which suggests a great volume of spilled products in a high concentration.

Nataly Filimonova, Operational Maritime Monitoring Group head of ScanEx, said that during satellite-based monitoring of the area of pollution local technology of operational satellite radar and optical data reception and in-depth processing were used, as well as processing of AIS system and meteo data.

A comprehensive analysis of satellite images and AIS data, performed by the specialists of federal institution AMP Novorossiysk together with their counterparts from ScanEx RDC allowed determining that within the area of the detected slick the Yukon Star tanker was located (flying the flag of the Great Britain). The ship performed a complicated and long manoeuvre right within the area of the detected pollution. It should be noted that the ship itself during the products dumping was detected on two satellite images of 23rd and 24th June with a long slick trail.

Based on the received information and preliminary investigation the tanker was subject to a detailed inspection after mooring in the next port in Tuapse to find what caused the pollution. According to the inspection carried out on 30th June by the inspectors of the Black Sea Inspection the ship was washing the tanks within the indicated area after offloading palm oil in the port of Yuzhny prior to loading gas oil. Such a procedure is allowed by the international conventions for the substances not threatening the sea environment or human health.

Dumping of flushing water from tankers after washing tanks is allowed only for certain categories of cargo and under certain conditions. "Detection of dumping from the tanker by satellite images, its identification and detection of reasons of the Black Sea pollution is a good experience of testing the application of satellite-based monitoring and investigation into illegal cases of dumping from ships", says AMP Novorossiysk Environmental Control Department head Vyacheslav Berdnikov.

Published: Spill-international (http://www.spill-international.com/news/id428-Tanker_Loosing_Oil_Discovered_in_Black_Sea.html)