Oyster beds and oil protection boom at The Nature Conservancy's Coffee Island oyster restoration project in the Gulf of Mexico just off the Alabama coast, south of Bayou La Batre.
Judy Haner, The Nature Conservancy’s marine program director in Alabama, tells us the latest in boom deployment efforts off the Gulf Coast of Alabama, talks about why oyster reef restoration is so important for the Gulf’s coastal habitats, and says that the Conservancy and its partners might soon have to make hard choices together about which habitats to save. Read all our posts from the front lines in Alabama, including those of Bill Finch, our director of conservation in Alabama.
Q: What’s the latest from the Alabama coast on preparations for the spill?
Judy Haner: First, there’s great news for Coffee Island, where we have one site in our Alabama oyster reef restoration project. The Coast Guard has tied their booms into the booms we put out earlier in the week and they’ve encircled the entire island with booms.
We actually now have booms everywhere on the coast. We have booms along the frontline barrier islands, all along the secondary islands, and all along our inland tributaries. It’s really impressive how all the coastal communities of the Gulf are coming together to accomplish this three-line defense. It’s been amazing.
Q: About Coffee Island — that’s where the Conservancy and its partners are building a “living shoreline” where erosion has eaten away at the island’s shore. What’s a “living shoreline”? And what’s critical about this project?
Judy Haner: We’ve got accelerated erosion along the northern Gulf Coast for potentially several reasons. Is it climate change? Is it sea-level rise? Is it development upstream diverting river flow? What we do know is that the Mississippi River delta is second in land loss per year only to the Nile River delta in Egypt — and Mobile Bay is part of that larger system.
In some areas of the Bay, we’ve got 10 feet or more of erosion per year along our saltmarsh communities, which are a critical coastal resource. That erosion also puts a lot of turbidity or sediment in the water column, and that causes problems for submerged marine resources such as oysters and seagrass, which want to have clear water.
If you were to walk up to one of the Bay’s islands from the Gulf, you might come across an oyster reef, a vertical relief of oysters coming out of the water — and one thing that oyster reef does is knock down the Gulf’s waves. Behind that reef, if you were to keep walking, you’d come into an area of calm water — an area where seagrasses grow and proliferate, providing essential nursery habitat for blue crabs, shrimp, speckled seatrout and flounder, to name a few.
But with the erosion and the decline of the oyster reef and other submerged habitats, this coastal area just gets pounded by waves. The saltmarsh, which holds soil in its roots, starts to break off, impacting the seagrasses. There’s almost a negative feedback loop here — more turbidity causes fewer oyster reefs and seagrasses, which causes even more erosion and turbidity.
Q: So that’s why the Conservancy is doing oyster reef restoration in the Gulf?
Judy Haner: Yes. We’re looking at ways to repair these systems on multiple levels — but we need to first mitigate the shoreline erosion.
The first step involves making breakwaters. We’re conducting experiments with three types of materials:
* Oyster reefs made out of bagged oyster shells;
* Reefballs — a concrete composite with rough exteriors that allow oyster larvae to attach; and
* ReefBlks — Rebar structures that are packed along the edges with bagged oyster shells.
We’re examining each of those three types of materials for how they function to protect shoreline and how they function as a settlement substrate — something for the oyster larvae to attach to and grow. We’re also looking at them as fish habitat. The question we’re trying to answer is: Which treatment functions best across those three variables — shorelines, fisheries and oysters?
And we’re looking at this in two places — Coffee Island, which is part of Mississippi Sound, and Alabama Port, on the western shore of Mobile Bay. 61% of the Coffee Island site has been deployed since we started in mid-April, while 25% at Alabama Port is deployed. We will have a mile installed at each site as part of this project, so we’re making significant progress.
Q: Both of these efforts were funded with NOAA stimulus funds, correct?
Judy Haner: Yes. And the really great thing that’s happened — because of the injection of funds from the stimulus package into this project, we were able to start to get preliminary data on these habitats back in December and January, collecting all sorts of shoreline data and fisheries data as a baseline.
Q: When you find out which of the three treatments is best, can that knowledge then be used elsewhere in shoreline protection?
Judy Haner: Absolutely. If we find another area that needs shoreline protection, we’ll know which of these treatments works best for a particular variable — fisheries, etc. Eventually we want to say: We know what’s going to work.
And this knowledge will be applicable in other areas outside the Gulf. For instance, the Mediterranean has a huge oyster population and significant reef areas. If an oil spill event were to happen there, this information could be very valuable to them.
Q: So the data you’re collecting would also be valuable in recovery and restoration from other oil spills?
Judy Haner: Right. Since we have all this great data, we can look at the environmental response depending on how bad the oil is, whether it’s just a sheen, whether it comes ashore in tarballs, or whether it comes ashore as a slick. Because we already have this reef restoration experiment going, it’ll give us several tools in the toolbox with which to approach restoration of these systems.
For example — if oil reaches into marsh areas, and we decide that fire might be an approach to removing that oil, we can study the results of a burned marsh for restoration rather than leaving it to do it on its own and what that recovery comparison would be. And we’ll know what works because of the baseline data we’ve collected.
Any of those types of tools we could test effectively through the footprint of the project to use in the Gulf Coast and in other areas. One of the things lacking with the Exxon Valdez spill was baseline data on the ecosystem. We have 10 years or more of data on these systems.
Q: Now that the booms are secured, what other work are we doing?
Judy Haner: We’re going to Grand Bay tomorrow morning to look at the salt marsh, salt pans and clapper rails that are nesting there.
These are sad days. We may lose some things. So the questions we will soon have to answer are: What is it that we do save, and what is it that we don’t save? We’re working with our partners — state and federal agencies and local officials — to define what that is. Do we choose an area with nesting clapper rails to save over a coastal salt marsh — which do we choose? What are the ecological priorities?
The partners are all working together on what our response is going to be when the oil comes ashore. And we’re also asking: “What is the research that we will need to know?” Because while we may lose some things, we want to learn as much from this as we can.
(Image credit: Mark Godfrey/TNC.)