The Royal Dutch Shell drilling rig Polar Pioneer that has been the focus of environmentalists while it was docked in Seattle left port on Monday for Alaska as the first step of a summer 2015 drilling campaign in the Arctic. Dozens of activists in kayaks dubbed “kayaktivists” tried to stop it, but the Coast Guard enforced the marine safety zone around the vessel and prevented any disruption. Around two dozen people were temporarily detained and fined $500 each for violations. Although final permits are still pending, Shell cleared major hurdles when a federal appeals court struck down a challenge to its oil spill response plans and after President Barack Obama upheld the 2008 Arctic lease sale. The U.S. Geological Survey estimates Arctic offshore reserves at 26 billion barrels of recoverable oil and 130 trillion cubic feet of natural gas. Shell says developing these reserves could increase domestic oil supplies by more than 1 million barrels a day.