Prospects for Wetland Recovery in the Northern Gulf of Mexico

• Date: 01 November 2010
• Author: Christopher J. Anderson, Catherine Artis, and Jacob Pendergrass

40 ELR 11090 ENVIRONMENTAL LAW REPORTER 11-2010

Prospects for Wetland Recovery

in the Northern Gulf of Mexico

by Christopher J. Anderson, Catherine Artis, and Jacob Pendergrass

Christopher J. Anderson is Assistant Professor at the School of Forestry and Wildlife Sciences and Associate Director for the Center for

Forest Sustainability at Auburn University. Catherine Artis is a recent graduate of the Department of Fisheries and Allied Aquacultures at

Auburn University. Jacob Pendergrass is a recent graduate of the Department of Biological and Environmental Sciences at Troy University.

The explosion of the BP oil rig Deepwater Horizon has

resulted in the single largest oil spill recorded in the

Gulf of Mexico.1 As a result, there are immediate and

long-term concerns regarding the environmental health of the

northern Gulf of Mexico (GOM) region (the Florida Pan-

handle to Texas). In this region, tidal wetlands are largely salt

marshes (non-forested wetlands), although there are also small

and highly scattered populations of black mangroves (Avicen-

nia germinans) along the coasts of Louisiana and Texas and

tidal freshwater wetlands (marshes and forests) within coastal

rivers and creeks.2 Oil spills have the potential to impact all of

these wetlands, but in terms of oil exposure and wetland area,

the greatest impacts are expected to salt marshes.

An estimated one million hectares (ha) of salt marsh occurs

along the GOM, with approximately 43% occurring in the

Mississippi River Delta.3 Salt marshes occur in the intertidal

zone, where there is sucient protection from wave energy

often near river mouths, bays, and in protected lagoons. Being

in the intertidal zone, they are subjected to daily tidal uc-

tuations a nd may alternate from drained to submerged on

a daily basis. In the northern GOM, tides are usually small

(<1 meter (m)), however, because of the at topography along

the coast, intertidal zones can be extensive. Salt marshes in

the GOM are dominated by rooted perennial grasses and

rushes, including: smooth cordgrass (Spartina alterniora);

salt meadow cordgrass (Spartina patens); salt grass (Distichlis

spicata); and black needle-rush (Juncus roemerianus).4 Few

plant species are adapted to survive in these marshes because

of highly anaerobic soils (caused by prolonged ooding) and

the added stress of sa linity. As a result, salt marshes are usu-

ally not species-diverse a nd often a single species will form

nearly homogeneous stands. e range of tidal ooding and

elevations within a marsh often promote discernable high-

and low-marsh zones that can be occupied by dierent species

1. Cutler J. Cleveland, Deepwater Horizon Oil Spill, in T E 

E (Cutler J. Cleveland ed., Environmental Information Coalition, Na-

tional Council for Science and the Environment, 2010).

2. W J. M  ., W E 295 (John Wiley & Sons,

Inc. 2009).

3. R W. T, F G  C W P   S-

 U S (Univ. of Mass. Press 1993).

4. Id.

or dierent growth forms of the same species.5 In addition

to tides and salinity, salt marsh vegetation is inuenced by

other factors, including substrate type (muds, sand, and peat),

climate (temperature, rainfall, and hurricane patterns), fresh-

water ow, biological competition, and surrounding land

use/human activities.6 Despite the stressful environment,

these marshes are often highly productive and complex eco-

systems with multiple bottom-up and top-down factors that

aect ecological processes.7 Salt marshes are fragile habitats

and extremely important breeding grounds for many species,

including those considered economically important for sh-

eries, such as brown shrimp (Farfantepanaeus aztecus), white

shrimp (Litopenaeus setiferus), blue crab (Callinectes sapidus),

and several pelagic sh.8 ey also provide important habitat

for species that make up the food base for other commercially

important sh species and species of conservation interest,

e.g., wading birds. Coastal marshes are also critical for shore-

line protection and storm-surge abatement,9 particularly with

increasing human development along the U.S. coastline. In

short, tidal marshes along the northern GOM are critically

important ecosystems.

e potential impact and recovery to salt marshes caused

by oil exposure is dicult to generalize, because of inher-

ent dierences between wetlands, the varying nature of oil

impacts, and the range of potential cleanup options that

could be employed. Predicting future conditions and recov-

ery is probably premature, because the full extent of damage

caused by this oil spill is still unknown. However, research

and accounts from past oil spills provide important lessons

for anticipating wetland impacts and selecting appropriate

management tools for recovery. We review some of these les-

sons learned and identify factors that will likely determine

the extent of wetland damage and recovery.

5. See M  ., supra note 2.

6. See T, supra note 3.

7. Jenneke M. Visser & Donald M. Baltz. Ecosystem Structure of Tidal Saline

Marshes, in C W: A I E A 425-

44 (G.M.R. Perillo et al. eds., Elsevier Science, 2009).

8. Lawrence P. Rozas et al., An Assessment of Potential Oil Spill Damage to Salt

Marsh Habitats and Fishery Resources in Galveston Bay, Texas, 40 M P-

 B. 1148-60 (2000).

9. John D. Day Jr. et al., Restoration of the Mississippi Delta: Lessons From Hur-

ricanes Katrina and Rita, 315 S 1679-84 (2007).

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