Salt Marsh Recovery After In-Situ Burning for Oil Spill Remediation: Effects of Water Depth and Burn Duration.
Salt Marsh Recovery After In-Situ Burning for Oil Spill
Remediation: Effects of Water Depth and Burn Duration.
Mendelssohn, I. A.; Lin, Q.; Carney, K.; Bryner, N. P.;
Walton, W. D.
NIST SP 995; Volume 2; NIST SP 995; 37 p. 2000.
Environmental Science and Technology, Vol. 36, No. 4,
oil spills; in situ burning; water; statistical analysis
Oil spills pose a serious risk to the health of wetland
systems. A cleanup technique that is compatible with the
wetland environment and is consistent with present
wetland management procedures would be highly valued.
In-situ burning of oiled wetlands potenually provides
such a procedure. However, the burning of wetlands can
have beneficial as well as detrimental impacts. Factors,
such as water depth over the soil surface, the season of
the burn, and burning intensity and duration may
influence the response of wetlands to the burn, yet
these factors have not been adequately addressed
scientifically. A mesocosm scale investigation was
conducted to study the effects of water depth, burn
duration, and oil application on the relationship
between recovery of marsh vegetation, soil temperature
and oil remediation. Marsh sods, which were collected
from a south Louisiana salt marsh dominated by Spartina
alterniflora, were instrumented with thermocouples and
assigned to the following treatments: (a) Oil exposure:
unweathered diesel (1.5 l/m2) versus no diesel
application, (b) Burn duration: 400 s (seconds) versus
1400 s (seconds), and (c) Water depth: -1O, -2, 0, and
10 cm of the marsh surface relative to the water level.
Soil temperature, as a function of soil depth and sod
elevation, was continuously recorded during the burn and
for a total of 5400 s post-burn. After the burns, the
mesocosms were returned to the greenhouse where plant
recovery was monitored. Soil samples for total petroleum
hydrocarbon and gas chromatography/mass spectrometry
(GC/MS) analyses were collected 24 hours after oil
addition and 1 day and 7 months post-burn.