For Jacqui Bergner, a U.S. Army Corps of Engineers aquatic biologist, the rumble of a dredging vessel's engine wasn't just noise—it was the sound of her office. For one week, she called the massive hopper dredge Essayons home, working 12-hour shifts sifting through thousands of pounds of sand and mud. Her mission: to monitor for the accidental “take” of threatened green sturgeon.