of a spill depends on prevailing winds, water currents, and temperature. 

 Toxicity to the biota depends on the temperature salinity, and the life 

 form and life stage exposed. Spill coverage of the marsh is a function 

 of the ambient currents, wind direction, and wind velocity. 



A crude oil spill causes a die-back of marsh vegetation above the oil 

 line within two or three days. Emergent grasses, sedges, and rushes are 

 most likely to be affected. Cleanup efforts effect similar results with 

 either burning or hand-cutting methods of removing contaminated stems. 

 Plant species left with intact root systems and large food reserves 

 recover within one year; less tolerant species require more time. If 

 large quantities of materials are not rapidly dispersed over wide areas, 

 mobile consumers capable of avoiding contaminated sustances leave the 

 area. Less mobile consumers may be coated with oil or other noxious 

 fractions and die; food and shelter resources become so degraded as to 

 provide only minor benefits to consumer groups which previously used the 

 site. Birds, particularly waterfowl and wading species, contaminated 

 their plumage by landing or wading in spilled oil. Bird mortality results 

 from exposure (due to a loss of insulation properties of the plumage) or 

 ingestion of toxic petrochemical compoungs (swallowed while the birds 

 attempt to clean oil from soiled feathers). Furbearers and other small 

 mammals within the impacted area may experience similar difficulties. 



Movement of men, marsh buggies, airboats, barges, outboards, and other 

 cleanup equipment over and through aquatic marsh areas disturbs soft 

 sediments, thereby increasing suspended sediments and dissolved nutrient 

 concentrations. Similar movements on firmer substrates cause partial 

 vegetation damage and rearrangement of surface configurations. Such 

 alterations occur within, as well as around, the actual spill area. Such 

 changes are considered to be temporary and restricted in nature; they are 

 of little consequence at the ecosystem level of consideration. 



Cleanup techniques involve all or some of the following procedures: 

 (1) placement of floating booms or containment skirts; (2) dispersal and 

 collection of absorbent/adsorbent materials; (3) burning; (4) excavation 

 and removal of contaminated plants and soils; and (5) application of 

 chemical dispersants or emulsifiers. Boom deployment by boat causes few, 

 if any, environmental alterations. Deployment and subsequent collection 

 of absorbent/adsorbent materials such as hay, straw, or specially manufac- 

 tured plastic sheets is usually accomplished with manual labor. Site 

 alterations are restricted to vegetation trampling and small surface 

 disturbances. Cleanup of amounts of residual oil too small to effi- 

 ciently remove with conventional collection techniques is accomplished by 

 burning the contaminated site. Producers, and consumers which do not 

 abandon the site are removed. Fire accelerates biomass decomposition, 

 thereby increasing the availability of soil nutrients. Removal of 

 standing plant materials and sediments soaked with oils lowers the local 

 land elevation and could produce some new areas of standing water. The 

 storage of unavailable nutrients is decreased slightly, but probably not 

 enough to affect the ecosystem. Toxic components of the spilled material 

 are prevented from affecting existing or future biotic elements when 



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