Effects of Disturbance Associated With Seismic Exploration for Oil and Gas Reserves in Coastal Marshes (original) (raw)
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Marine Pollution Bulletin, 1996
The impact of south Louisiana crude oil on the dominant vegetation, Spartina alterniflora, Spartina patens and Sagittaria lancifolia, of three types of coastal wetlands, salt, brackish and freshwater marshes, respectively, was studied. In the greenhouse, south Louisiana crude oil was applied to natural marsh sods at rates of 0, 4, 8, 16 and 24 I m-2. The photosynthetic rate of S. patens significantly decreased with increasing oil dosage after 1 month of oil application, while the photosynthetic rate of S. alterniflora was not significantly reduced by oil application until 3 months. The photosynthetic rate of S. lancifolia was not detrimentally affected by the oil treatments. Four months after oil application, live above-ground biomass production was significantly reduced at higher oil dosages for S. patens, was not affected in S. alterniflora, while S. lancifolia exhibited significantly higher total biomass at 24 i m-2 compared to the controls. The year following oil application, no regrowth of S. patens and S. alterniflora occurred at oil levels above 8 1 m -2. In contrast, the regrowth of above-ground biomass of S. lancifolia increased with increasing oil dosage and resulted in monospecific communities at 16 and 24 1 m -2. Furthermore, the residual oil in the soil greatly differed among the three marsh-types, with the highest concentrations in the S. patens soil sods and the lowest concentrations in S. alterniflora soil sods. This difference in oil residue among the marsh-types was mainly due to differences in soil organic content. The sensitivity of these marsh-types to south Louisiana crude oil increased in the following order: 5;. lancifolia, S. alterniflora and S. patens.
Journal of Marine Science and Engineering, 2016
April 20, 2010 marked the start of the British Petroleum Deepwater Horizon oil spill, the largest marine oil spill in US history, which contaminated coastal wetland ecosystems across the northern Gulf of Mexico. We used hyperspectral data from 2010 and 2011 to compare the impact of oil contamination and recovery of coastal wetland vegetation across three ecologically diverse sites: Barataria Bay (saltmarsh), East Bird's Foot (intermediate/freshwater marsh), and Chandeleur Islands (mangrove-cordgrass barrier islands). Oil impact was measured by comparing wetland pixels along oiled and oil-free shorelines using various spectral indices. We show that the Chandeleur Islands were the most vulnerable to oiling, Barataria Bay had a small but widespread and significant impact, and East Bird's Foot had negligible impact. A year later, the Chandeleur Islands showed the strongest signs of recovery, Barataria Bay had a moderate recovery, and East Bird's Foot had only a slight increase in vegetation. Our results indicate that the recovery was at least partially related to the magnitude of the impact such that greater recovery occurred at sites that had greater impact.
Environments, 2015
The present review summarizes the literature on the effects of oil spill on the U.S. Gulf of Mexico coastal vegetation including freshwater-, brackish-, and salt-marshes. When in contact with plant tissues, oil may have adverse impacts via physical and chemical effects. Oil may also become detrimental to plants by covering soil surfaces, leading to root oxygen stress and/or penetrate into the soil where it becomes in contact with the roots. The affected vegetation may survive the impact by producing new leaves, however, an episode of oil spill may impose severe stress. Oil spills may lead to partial or complete plant death but in many situations plants recover by regenerating new shoots. Plant sensitivity to oil varies among species; plants from salt marshes appear to be more sensitive than freshwater species. In addition, sensitivity appears to be dependent on the oil characteristics and the quantity of oil being spilled, repeated oiling events, season of spill, greenhouse vs. field conditions, and plant age are among the many factors that interact simultaneously. Many aspects of coastal plant responses to oiling remain in need of additional research, including the possibility that differences in oil sensitivity may interact with changes in the environment, and contribution to additional wetland losses through coastal erosion. Environmental stressors such as drought and salinity may also interact with oil, leading to the observed changes in plant species community composition following an oil spill.
Impacts of the Deepwater Horizon oil spill on the salt marsh vegetation of Louisiana
Environmental pollution (Barking, Essex : 1987), 2016
The coastal wetland vegetation component of the Deepwater Horizon oil spill Natural Resource Damage Assessment documented significant injury to the plant production and health of Louisiana salt marshes exposed to oiling. Specifically, marsh sites experiencing trace or greater vertical oiling of plant tissues displayed reductions in cover and peak standing crop relative to reference (no oiling), particularly in the marsh edge zone, for the majority of this four year study. Similarly, elevated chlorosis of plant tissue, as estimated by a vegetation health index, was detected for marsh sites with trace or greater vertical oiling in the first two years of the study. Key environmental factors, such as hydrologic regime, elevation, and soil characteristics, were generally similar across plant oiling classes (including reference), indicating that the observed injury to plant production and health was the result of plant oiling and not potential differences in environmental setting. Althoug...
SALT MARSH RECOVERY FROM A CRUDE OIL SPILL: VEGETATION, OIL WEATHERING, AND RESPONSE
International Oil Spill Conference Proceedings, 1993
Responding to oil spills in marshes is always problematic, since inappropriate response activities can easily add to the overall damage to the marsh. When a spill of Prudhoe Bay crude oil covered a fringing Salicornia virginica marsh in Fidalgo Bay, Washington (northern Puget Sound) in February 1991, response personnel used several low-impact techniques to remove oil from the marsh, and minimized access by cleanup workers. Following the response, we established a monitoring program to track marsh recovery, and to document the effectiveness of the response techniques used and their impacts on the marsh.
Oil and Chemical Pollution, 1990
A pipeline break on 23 April 1985 near Nairn, Louisiana, resulted in the release of approximately 300 barrels of Louisiana crude oil into a brackish marsh dominated by a vegetative mixture of Spartina patens, S. alterniflora and Distichlis spicata. Since the impact of oil spills on brackish marshes has received little attention, we initiated this investigation to assess the post-spill status of the vegetation. Sixty-eight randomly selected plots located on 15 transects which traverse the complete study area were sampled for various vegetative cover parameters. The major impact of the spill was confined to the 50-acre (20-ha) marsh located immediately around the pipeline rupture. The oil caused a 64% reduction in live vegetative cover (adjusted for differences in total percentage cover among plots) in this marsh 3 months after the spill. This high plant mortality from a relatively low oil dosage (estimated at 0.28 liters/m 2) was probably due to the contact of the oil with a large percentage (about 30-70%) of the photosynthetic leaf surfaces of the vegetation and the penetration of the oil into the marsh substrate.
In Situ Burning Restores the Ecological Function and Structure of an Oil-Impacted Coastal Marsh
Environmental Management, 2010
As the use of in situ burning for oil spill remediation in coastal wetlands accelerates, the capacity of this procedure to restore the ecological structure and function of oil-impacted wetlands becomes increasingly important. Thus, our research focused on evaluating the functional and structural recovery of a coastal marsh in South Louisiana to an in situ burn following a Hurricane Katrina-induced oil spill. Permanent sampling plots were set up to monitor marsh recovery in the oiled and burned areas as well as non-oiled and non-burned (reference) marshes. Plots were monitored for species composition, stem density, above-and belowground productivity, marsh resiliency, soil chemistry, soil residual oil, and organic matter decomposition. The burn removed the majority of the oil from the marsh, and structurally the marsh recovered rapidly. Plant biomass and species composition returned to control levels within 9 months; however, species richness remained somewhat lower in the oiled and burned areas compared to the reference areas. Recovery of ecological function was also rapid following the in situ burn. Aboveground and belowground plant productivity recovered within one growing season, and although decomposition rates were initially higher in the oiled areas, over time they became equivalent to those in reference sites. Also, marsh resiliency, i.e., the rate of recovery from our applied disturbances, was not affected by the in situ burn. We conclude that in situ burning is an effective way to remove oil and allow ecosystem recovery in coastal marshes.
OBOT UTIBEMFON RICHARD, 2023
Large oilfields are often coincidentally located in major river deltas and wetlands, and potentially damage the structure, function and ecosystem service values of wetlands during oil exploration. In the present study, the effects of crude oil contamination during oil exploration on soil physical and chemical properties were investigated in marshes of the Momoge National Nature Reserve in Jilin Province, China. The concentrations of total petroleum hydrocarbons in the marsh soil near the oil wells are significantly higher than those in the adjacent control marsh. Soil water contents in oil-contaminated marshes are negatively correlated with soil temperature and are significantly lower than those in the control area, especially in fall. Crude oil contamination significantly increases the soil pH up to 8.0, and reduces available phosphorus concentrations in the soil. The concentrations of total organic carbon are significantly different among sampling sites. Therefore, crude oil contamination could potentially alkalinize marsh soils, adversely affect soil fertility and physical properties, and cause deterioration of the marshes in the Momoge National Nature Reserve. Phyto-remediation by planting Calamagrostis angustifolia has the potential to simultaneously restore and remediate the petroleum hydrocarbon-contaminated wetlands. Crude oil contamination affects the soil physical and chemical properties, so developing an effective restoration program in the Momoge wetland is neccesary.