Background information and definitions
Oil spills can damage vegetation in marshes and swamps. Lighter oils can kill plants through their toxic effects, whilst heavier oils coat and smother vegetation (Michel & Rutherford 2013). Coastal salt marshes and mangroves are vulnerable to offshore tanker spillages. An estimated 5.5 million tonnes of oil has been released into mangrove-lined coastal waters around the world since 1958, killing at least 126,000 ha of mangrove vegetation (Duke 2016). Oil pipelines crossing inland marshes or swamps (e.g. the Russia-China Oil Pipeline; Yu et al. 2010) pose a threat from leaks and malfunctions. Loss of vegetation can increase the risk of erosion and permanent habitat loss (Beland et al. 2017; https://youtu.be/UkATPicHIo4).
This action includes a range of specific actions that directly remove or break down oil, such as picking up lumps of oil, removing oil-contaminated litter/wrack/sediment, vacuuming, washing, sand-blasting, using chemical cleaners, and adding chemical dispersants. For more information about implementing these techniques, see ExxonMobil (2008), Michel & Rutherford (2013) and Hoff & Michel (2014). The effectiveness of these actions may depend on the type of oil, exposure to waves and currents, climate, time of year that the spill occurred, and the species involved (Michel & Rutherford 2014). Caution: Interventions to remove oil could kill any surviving vegetation and churn oil into the sediment, potentially hindering long-term recovery.
Related actions: Use artificial barriers to block pollution; Cut or burn oil-contaminated vegetation (freshwater marshes – brackish/salt marshes – freshwater swamps – brackish/saline swamps); Stimulate microbial breakdown of oil.
Beland M., Biggs T.W., Roberts D.A., Peterson S.H., Kokaly R.F. & Piazza S. (2017) Oiling accelerates loss of salt marshes, southeastern Louisiana. PLoS ONE, 12, e0181197.
ExxonMobil (2008) Oil Spill Response Field Manual. ExxonMobil, USA.
Hoff R, & Michel J. (2014) Oil Spills in Mangroves: Planning & Response Considerations. US Department of Commerce.
Michel J. & Rutherford N. (2013) Oil Spills in Marshes: Planning & Response Considerations. US Department of Commerce.
Michel J. & Rutherford N. (2014) Impacts, recovery rates and treatment options for spilled oil in marshes. Marine Pollution Bulletin, 82, 19–25.
Yu X., Wang G., Zou Y., Wang Q., Zhao H. & Lu X. (2010) Effects of pipeline construction on wetland ecosystems: Russia-China Oil Pipeline Project (Mohe-Daqing Section). Ambio, 39, 447–450.