Georgia officials have signed off on a plan to raise Savannah’s towering suspension bridge to make room for larger cargo ships to reach the city’s busy seaport.

Army Corps of Engineers scientists drift in a boat toward a plume of red dye in the Savannah River, Ga., as they test large machines designed to boost oxygen levels in the river. SAVANNAH, Ga. - Conservation groups "remain skeptical" that machines injecting oxygen into the Savannah harbor will offset threats to fish caused by deepening the busy shipping channel to the Port of Savannah, but they won't return to court to fight the $973 million project, according to the environmental groups' attorney. Conservation groups and South Carolina state agencies had sued the Army Corps in federal court, arguing the harbor expansion would cause irreversible environmental damage. A settlement reached in 2013 stated that the plaintiffs could terminate the deal if the Corps couldn't prove the oxygen machines worked. DeScherer's letter said the environmental groups that sued won't scrap the settlement despite their doubts about the oxygen machines.