Tossing Mullet

There was a workshop recently in the Panhandle held by NOAA’s (National Oceanic and Atmospheric Administration) office for coastal research, which was intended to scavenge the brainpower of the Mississippi-Alabama-Panhandle region concerning research needs relative to sea level rise.

The intriguing issue lies buried in the confusing notion that while sea level is definitely rising globally, the adjacent land level may also be moving up or down? Relative to what? – you may ask! There are parts of our continental landmass that are actually rising.

Think of it as that flagstone patio that you were too lazy to level the base with sand before you laid the stones. Some are tipping down, raising the other edge. The west coast is more threatened by the rising edge breaking off and falling into the Pacific Ocean than being flooded, while the southeast region, including the Gulf, is much more exposed to inundation.

The reason that the Louisiana coastal region, including New Orleans, is so very vulnerable is due to the undisputed reason that the land is sinking under the weight of centuries of deposited sediment (mud), which is actually tipping the geological plate there downwards. But there is not enough now being deposited to keep up with the rising water level – thus the plans to redistribute more mud into the delta rather than sending it down the river to the depths of the Gulf where it does little or no good for anyone.

Plus, the situation in Louisiana and Texas is greatly exacerbated by the fact that enormous amounts of gas, oil, and associated stuff have been pumped out from under the land over the decades, adding to settling. The recurring use of the word, “relative,” should be becoming clearer to you by now.

So, what about the central Gulf? The first geologist hired at the University of South Alabama, Dr. George Lamb, actually foresaw and addressed this issue and published a paper many years ago. George believed that there was a relative sinking of our own particular “flagstone” near Memphis, meaning our coast line was, in fact, coming up – or at least keeping up with rising ocean levels.

That was a major reason for his professional belief that we were relatively secure in developing our coast. He and Dr. Robert Dean, one of the country’s foremost coastal engineers, drew up the original Coastal Construction Control Line for the State of Alabama. A line of concrete monuments, parallel to the shoreline was established from the Florida line to the end of the paved road on Dauphin Island by the Alabama Department of Environmental Management (ADEM). This was completed in the ‘80s and is still in place – except, of course, for those monuments that have fallen into the advancing Gulf of Mexico!

I suppose the assessments and predictions of the ‘70s by Drs. Lamb and Dean did not have the benefits of our current concern for climate change, which includes a more rapid rise in relative sea level as well as increased tropical storm activity.

There are two broad efforts in habitat preservation and shoreline stabilization ongoing at the federal, state and local levels. One addresses the relatively natural habitats of oyster reefs, submerged aquatic vegetation (grassbeds) and the emergent vegetation of our coastal marshes and swamps, while the other deals rather explicitly with the human habitat features of houses, roads, water, sewer and power.

A variety of entities ranging from NOAA, the Alabama Department of Conservation and Natural Resources, Mississippi/Alabama Sea Grant, The Nature Conservancy, the Dauphin Island Sea Lab and the Mobile Bay National Estuary Program are all spending money in a laudable effort to restore, maintain and stabilize the various habitat types mentioned above for the ecosystem services they provide .

But (why is there always a “but”?), the efforts seem to be largely aimed at putting them back where they were or enhancing them where they are now, with too little thought and money being expended on where they might be in 50 years if the “creek” is rising! Oysters may not care if there is another six inches of water over their head, but if it’s saltier they are going to be more rapidly consumed by the natural predator, the oyster drill (a snail that is the bane of the oyster industry).

The floral habitats actually care a great deal about the water over and around them and the populations will try to move up and ahead of the rising water level, no matter how small.

And then (why is there always an “and then”?) they encounter our other habitat stabilization and enhancement project – us! Enormous sums of money have been poured into keeping human habitat in place; engineering storm-resistant structures, bulkheading shorelines and generally operating on the assumption that we can handle anything that Mother Nature throws at us. Houses and buildings, even on the west end of Dauphin Island, are now much better constructed and elevated.

If the property owners would stop asking taxpayers to rebuild the roads, water, sewer, power and beach habitats, I would have no problem with their building a fishing camp with a generator and a dock for their boat, but they have to haul their waste back with them!

The worst sea level rise scenario frankly doesn’t threaten the mainland all that much except where it is quite low, but there has been a strong preference for bulkheading, leading Dr. Scott Douglass, the most experienced of our local coastal engineers, to describe the “bathtub” effect for Mobile Bay. The consequences of the walls along our engineered shoreline are dire for the natural habitats described above. They may be able to migrate landward along naturally gentle slopes, but none of the species concerned, which include shrimp, crabs and roughly 90 per cent of our commercial Gulf seafood can scale that bulkhead without some serious adaptations!

Frankly I have to think that there is a good chance that we are carefully aligning the deck chairs on the Titanic, the afternoon of April 14, 1912.

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George Crozier is Lagniappe columnist. Contact him at GCrozier@bellwether-group.com.

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