Romania\'s governement wants to step up the fight against illegal fishing in the Danube delta, a natural zone listed on UNESCO\'s World Heritage list, the environment minister said on Monday.\"We have to take all necessary measures to stop the decrease of fishing stocks in the Danube delta. (...) We will be strict and we will not tolerate any breach of the law\", Laszlo Borbely said during a visit to the area in eastern Romania, close to the Black Sea. He pledged to create \"inauspicious times\" for fish poachers by reinforcing checks. About 5,000 tonnes of fish are illegally captured every year, according to a study by the National research institute for the Danube delta.The waters of the Danube form the largest and best preserved of Europe\'s deltas. Listed since 1991 as a UNESCO World heritage, it hosts over 300 species of birds as well as 45 freshwater fish species in its numerous lakes and marshes.