The border guards and the navy will step up their crackdown on illegal fishing in Russian territorial waters this summer using a massive flotilla of ships and dozens of aircraft, the guard's commander in chief said Friday.Coast guards will conduct widespread vessel checks from June 20 to July 10 in an operation called Zaslon, or Shield, on the Barents, Black, Azov and Caspian seas. The operation will extend to the Chudskoye Lake in northwestern Russia and the Siberian rivers Amur and Ussuri, Major General Andrei Nikolayev said.The forces will implement the second stage of operation Putina, or Dragnet, aimed at preventing illegal fishing and pollution in the Pacific Ocean, Nikolayev told a news conference.He said about 60 percent of the 1,000 ships and 300 aircraft under his command will be deployed.Nikolayev said the measures, scheduled to continue into late autumn, will check huge economic losses suffered as a result of violations of its territorial waters. The first stage of Putina alone prevented damages worth 120 billion rubles ($61.4 million), he said.Andrei Alyoshin, a spokesman for the Federal Border Service, said one coast guard ship on the Barents Sea prevented $3.2 million worth of fish being smuggled out of Russia during 11 days of patrolling in late May and June.On five occasions guards supported by aircraft fired warning shots to persuade trespassers from Japan to leave Russian waters, Nikolayev said.