Salt Marsh Recovery and Oil Spill Remediation After In-Situ Burning: Effects of Water Depth and Burn Duration.
Salt Marsh Recovery and Oil Spill Remediation After
In-Situ Burning: Effects of Water Depth and Burn
Lin, Q.; Mendelssohn, I. A.; Carney, K.; Bryner, N. P.;
Walton, W. D.
Environmental Science and Technology, Vol. 36, No. 4,
oil spills; in situ burning; water; diesel fuels
Effects of water depth, burn duration, and diesel fuel
concentration on the relationship between recovery of
marsh vegetation, soil temperature, and oil remediation
during in-situ burning of oiled mesocosms were
investigated. The water depth over the soil surface
during in-situ burning was a major factor controlling
recovery of the salt marsh grass, Spartina alterniflora.
Ten centimeters of water overlying the soil surface was
sufficient to protect the marsh soil from burn impacts
with soil temperatures <37 deg C and high plant survival
rate. In contrast a water table 10 cm below the soil
surface resulted in mean soil temperatures> 100 deg C at
the 2-cm soil depth, which completely inhibited the
post-burn recovery of S.alterniflora. Although poor
plant recovery was also apparent in the treatments with
0 and 2 cm of water over the soil surface, this result
was likely due to the chemical stress of the diesel fuel
used to create the fire rather than the heat per se,
which never reached the estimated lethal temperature of
60 deg C. In-situ burning effectively removed more than
95% of floating oil from the water surface. Thus,
in-situ burning prevented the oil from potentially
contaminating adjacent habitats. However, in-situ
burning did not effectively remediate the oil that had
penetrated the soil.