Authorities in northern Greece are to use state-of-the-art technology to detect the location of about a ton of garbage believed to be lying on the seabed of the Thermaic Gulf off Thessaloniki before a cleanup operation can get under way. Local diving experts will collaborate with environmental protection groups in implementing side-scan sonar techniques, which use sound waves to detect objects on the sea floor, said Macedonia-Thrace Minister Margaritis Tzimas. This exercise will produce three-dimensional maps determining the location of large pieces of refuse – such as fragments of shipwrecks, cars and sections of jetties. These maps can then be used as a point of reference in a subsequent anti-pollution exercise, Tzimas said. If the initiative is a success, it may be extended to other sections of the country’s coastline that are heavily polluted, the minister said. Experts have warned that the Thermaic Gulf could become a «dead sea» in 30 years, as tons of agricultural and industrial waste are flowing into it on a daily basis.