The U.S. Army Corps of Engineers opened the Bonnet Carre Spillway on Friday, while the wildlife in the Mississippi Sound is still struggling to recover after the spillway's opening in February.
The spillway was opened "in an abundance of caution …," the Corps of Engineers said in a press release issued Friday, "to ensure the safe passage of this high water by limiting the elevations down-river of the spillway."
The spillway was built in 1931 to help prevent flooding in New Orleans and surrounding communities, but until this week had only been opened 13 times in its history. Friday marked the first time it had ever been opened twice in the same year.
The reason it is rarely opened, Corps officials said, is to limit the impact of the freshwater entering the Lake Pontchartrain basin and the Mississippi Sound.
Last month saw unprecedented damage to the Sound's habitat, with 28 dolphins and 57 sea turtles found dead along the Gulf Coast in April alone.
"This has been a really serious situation," Dr. Moby Solangi, executive director of the Institute for Marine Mammal Studies (IMMS) in Gulfport, said last month after a Kemp's Ridley turtle was found washed up on the beach in Waveland.
The dead dolphins and turtles all seem to have suffered from skin and eye lesions that are consistent with freshwater damage, Solangi said.
Due to the opening of the spillway, "A very significant amount -- trillions and trillions of gallons of fresh water over a long period of time -- has been introduced to the Mississippi Sound …," Solangi said. "When a huge amount of fresh water comes in like that, it significantly alters the habitat.
"In addition, if you put this huge slug of freshwater and silt and mud and clay and all that effluent that's up in the Mississippi River -- and fertilizer and all of that -- that's not where the water from the Mississippi Sound normally comes from. The Mississippi River drains these effluents. It's not only fresh water, it's all these other components. You're now introducing that water into a body of water that's not used to it."
"We need to be looking deep into" ways to fix the continuing problems, Solangi said. "The spillways were created in the early 1900s. We need to rethink our strategies."
To report dead or stranded marine life, call the IMMS at 888-767-3657.