The Dead Zone. It sounds ominous, mysterious.
“So it’s a phenomenon that, to my understanding, didn’t even really exist before the 1970s, but is an environmental response to high nutrient loads, primarily nitrogen and phosphorous,” says Seth Blitch, Coastal Program Manager for The Nature Conservancy in Louisiana.
All those nutrients delivered to the Gulf are like a buffet for algae. They feast on this newly found food supply. The feeding causes them to rapidly reproduce, creating huge algal blooms. Those algae soon die and their decomposition removes oxygen from the water. That’s a problem for marine life.
“It’s an area where you can’t live, it would be just like anywhere,” says Judy Palermo. She’s a spokeswoman for the Indianapolis Zoo.
A quick geography lesson explains why a zoo in Indianapolis is so concerned with something happening nearly a thousand miles away in the Gulf of Mexico. The Wabash River runs through Indiana. It flows into the Ohio River, which eventually joins the Mississippi River.
“One of the tenets of conservation ecology is that everything is connected in some way,” says Blitch. “That’s true everywhere and it’s evident in the Gulf and the Mississippi River Basin. The Basin itself drains about 41-percent of the United States.”
The Mississippi River Basin connects Indiana and Louisiana ecologically. This infrastructure delivers the nutrients that creates the Gulf’s Dead Zone.
According to Blitch, the Dead Zone forms largely off the coast of Louisiana from the mouth of the Mississippi, west. “Typically when you have higher flows in the Mississippi River you have a larger Dead Zone because you’re just delivering more water which carries more of those nutrients with it.”
Palermo adds that 10-11% percent of the nitrates and phosphates in the Gulf come from Indiana.
To educate visitors on the Dead Zone, the Indianapolis Zoo is revamping their dolphin exhibit. As part of the new exhibit, The Nature Conservancy helped the Zoo film a video of wild dolphins swimming off the coast of Grand Isle.
While dolphins can always swim out of the Dead Zone, they’re still affected by it. Blitch explains how.
They don’t kill fish directly. But what happens is, in the case of the dolphin for instance, dolphin feed primarily on fish, they love fish, so when those fish leave the area of the Dead Zone, those dolphin aren’t going to be there either because there’s nothing to eat and they’ll also leave and follow and the fish.
Agricultural runoff, rich with nitrogen and phosphorous, is commonly blamed for the Dead Zone. Blitch isn’t quick to point fingers, though. “We have a board member who says, ‘Never criticize a farmer with your mouth full.’ If we’re talking about the Dead Zone it’s not an issue you can point to anybody, again, to me it’s a societal thing.”
And Blitch says that makes finding a solution complicated.
Nutrients by themselves aren’t inherently bad. It’s a combination of a lot of different practices, whether they’re agricultural or its impervious surfaces or how waters are treated or not treated and then how those waters are available or not available to marshes, which can actually also absorb nutrients. So it’s complex, because it’s connected.
Judy Palermo hopes the dolphins at the Indianapolis Zoo will establish an emotional connection between their wild cousins in the Gulf and the audience. “We always say we’re a conservation organization that just happens to have a zoo. By seeing this video, when people see one of the animals they’re kind of ambassadors for their species in the wild.”
Because of the Mississippi River Basin, Indiana and Louisiana are linked.
“The choices we make in Indiana don’t just affect us,” Palermo says. “They affect animals states away.... So we’re not just living on an island.”