Relationship of Spartina alterniflora growth to sediment oil content following an oil spill

A single spillage of crude oil in a salt marsh is generally considered to have limited biological effects. A crude oil spill in Dickinson Bayou (Galveston Bay system of Texas) in January 1984 provided the opportunity to test this concept in salt marshes exposed to varying amounts of oil. Growth of Spartina alterniflora was unaffected in light to moderately oiled sediments; however, S. alterniflora growth was significantly reduced in sediments with high oil content through 18 months. Erosion of shoreline areas with high oil content was evident by 16 months and had continued through 32 months. These results demonstrate the adverse effect of high concentrations of crude oil in salt marsh sediments. Therefore, each crude oil spill must be evaluated for the likelihood of significant accumulation of oil in sediment before a decision is made regaurding a cleanup response.