About 2,500 penguins en route to their Antarctic mating grounds could be sickened by a diesel fuel spill from a cruise boat that struck an iceberg and sank last week, Chilean scientists said. Areas surrounding the 1.6-km-long spill site include breeding grounds for Antarctic and Adelia penguins, and the largest mating colony for Papua penguins, said Maria Jose Rosello, a Chilean marine biologist. "The danger is that this fuel spill will impede the journey that species like Papua penguins make at this time of year," Rosello said. Veronica Vallejos, director of the scientific department at the Chilean Antarctic Institute, said the spill could also affect other Antarctic fauna, including sea lions, seals and sea birds as well as fish, krill, algae and plankton colonies - key elements of the Antarctic food chain. "There's always environmental danger when fuel leaks, and even more so in a zone with high biodiversity," Vallegos said. The MS Explorer, an adventure travel ship on a 19-day cruise off Antarctica, hit an iceberg on November 23, forcing its 154 passengers and crew into lifeboats in the middle of the night. They waited more than three hours in icy waters until they were rescued by a Norwegian cruise ship. About 190,000 litres of diesel, 24,000 litres of lubricant and 980 litres of petrol were on board when the Explorer sank hours later. Chile's navy said on Thursday bad weather has kept clean-up crews from containing the spill now penned in by large chunks of floating ice in the Bransfield Strait, about 80 km east of King George Island. "The diesel oil continues flowing" from the ship, which now rests 4,800 feet (1470 metres) below the sea, Vallegos told Cooperativa radio. Vallegos and other Chilean experts who toured the spill site reported seeing no contaminated birds this week, but noted they hadn't been able to fully assess the damage the diesel might have done. Studies by scientists who regularly conduct research in Antarctica at this time of year will be key to establishing the extent of the damage, she said. Diesel is the least harmful type of hydrocarbon product, scientists told a news conference on Thursday.