WaterMarks Interview: John Day, LSU

Dr. John Day is a Distinguished Professor in the Department of Oceanography and Coastal Science at Louisiana State University.

WaterMarks: How big a problem is this Dead Zone? Is hypoxia something that’s been around for years and we only just noticed it?

DAY: I think this is a very serious problem, a growing problem that will only get much, much worse. Louisiana has two big problems, wetlands loss and hypoxia. They are related, with the potential in the coming decade for us to see catastrophic results.

WaterMarks: So far the fisheries, the shrimpers and the recreational fishing industries have not been adversely affected by the Dead Zone. So why is this so important?

DAY: There is a growing consensus, a strong expectation that this problem is going to become a critical one. How long will it be before the Dead Zone is so big that the fish simply run out of habitat to escape to? How long will it be before the coast is so fragmented that there is no coast left? We don’t know if the problem will just get worse and worse gradually or if we will reach a critical threshold when the entire Louisiana fishery will collapse.

It’s wrong to focus on just Louisiana. This is a national problem, a distributed problem and we need a distributed solution. We are all unified by this huge river system; we are all part of the problem; and we can and should be part of the solution. If we can reverse the trend of the last 50 years, reduce the hypoxia, reverse or at least slow the coastal wetlands loss, maybe we will be lucky enough to never find out how big a disaster this might have become.

WaterMarks: Are the farmers to blame for this mess?

DAY: It would be a huge mistake to blame farmers for this problem. Nobody ought to be pointing a finger at anyone else. This is our problem in the same way that Louisiana’s wetlands loss is our problem, the nation’s problem.We were achieving national goals, agricultural production and flood control, as we created these problems. Now we need to make new national goals to solve these problems. We need to work together with the farmers and say “Hey, look, we need you to use only 2 or 3 percent of your farmland to make a first filter for the fertilizer runoff.”

This is a win-win solution. The farmer saves money on fertilizer and gets a green area with more birds and other wildlife. A system for creating nitrogen credits in the same way as carbon credits are used to prevent global warming would help even more.

We would all get cleaner local water sources with all the health benefits of that. We would get flood reduction too, because the wetlands absorb the excess rainfall and some of the over-bank waters.

WaterMarks: Is it more important to solve the problem upstream first? How important are the Louisiana wetlands in solving this problem?

DAY: Most of the problem is in the upper parts of the basin. Maybe 5 to 10 percent of the problem could be solved in Louisiana but I think it is important for Louisiana to be able to say it is doing its part. The delta wetlands can act as the “polisher” in removing the last bit of excess nitrogen, making the load of the river water that heads out to the Gulf in the range of 0.5 mg/liter, right what it should be.

WaterMarks: Can river-water reintroductions help? How can we be sure we aren’t going to make the estuaries hypoxic instead of the Gulf?

DAY: Reintroductions are the way to go for this problem. I am not too worried about hypoxia in the estuaries. They are too shallow and mix every day. There is no stratification. The danger to the estuaries is the possibility of algal blooms, possibly toxic ones. But the data at Caernarvon show that it is possible to get a significant drop in nitrogen levels across the area between the reintroduction and the estuary.

WaterMarks: If reintroductions can help, what is the best way to use a reintroduction?

DAY: The best way to use a reintroduction is to send the water through in pulses, more water in a little time rather than a moderate flow of water all the time. Pulsing gets more water up and over the marsh surface, causing more sediment to be deposited and more nitrogen to be taken up. Robert Twilley of Louisiana State University has found that denitrification is much more efficient when the water leaves the channels, because the water is warmed by 5 to 10 degrees Celsius. The oyster beds also benefit because the low-salinity water is not constantly in the channels but is out on the marsh.When I began the pulsing study at Caernarvon, the preliminary data were so overwhelmingly positive that the study was not even finished before pulsing was adopted as the best management plan for that reintroduction.

WaterMarks: Does it look like there will be any funding for these projects, or for further research?

DAY: Right now we have piecemeal studies and we are trying to link these all together. I would like to see a large federal, state and private program, an integrated program, stretching from Minnesota down to Louisiana, doing research, buying land for conversion to wetlands, promoting nitrogen credits for farmers. I’m optimistic about it.We have an enormous opportunity to bring all players together in a win-win situation to move us down the road towards solving this problem.

WaterMarks: Don’t we already know enough about the causes of the Dead Zone? Why should we do more research?

DAY: To those who say that we don’t need any more research, I answer that the research here is not just academic study without practical results. It is done on the ground, meaning that each time study is done, that wetland becomes part of the solution. Each study tells us more about where a wetland needs to be placed relative to the fertilizer source, how big it needs to be and how the water should flow through it for the best results.

Understanding where the wetlands should be is as important to the solution as knowing that we need them. A wetland that is improperly placed may attract ducks and other wildlife but it doesn’t act as a filter for the adjacent farmland.

WaterMarks: Assuming that your big plan goes into effect, how many years might it be before we see any improvement? What is going to be happening during those years?

DAY: We’re talking about a bunch of little steps that may need to be spread out over three decades of wetland restoration. But there will be a direct relationship to the hypoxia of the Gulf. Every little bit is going to help. But, just as importantly, the people in the rest of the watershed will be able to say “Hey, there are more birds around, the local drinking water is cleaner, the flooding is not as severe and we spend less money on fertilizer.We helped our neighbors in Louisiana too, and that means we can buy fish and shrimp for dinner!”