A conservation group is suing in federal court over a U.S. agency's timeline for dredging a Georgia shipping channel, saying dredging in the summertime would threaten rare sea turtles. A lawsuit filed in U.S. District Court in Savannah targets the Army Corps of Engineers. Georgia environmental group One Hundred Miles says the agency plans to conduct harbor dredging off the port city of Brunswick next summer during the nesting season for rare loggerhead sea turtles. The Army Corps has avoided maintenance dredging outside the winter months in Georgia and the Carolinas for three decades to help protect sea turtles. An Army Corps spokeswoman declined to comment on pending litigation.