Long‐term consequences of residual petroleum on salt marsh grass

Abstract

Summary 1.Remnants from oil spills can persist for decades within anoxic coastal sediments affecting local flora and fauna, but few studies have examined the long-term impacts of the residual petroleum on these valuable coastal ecosystems. 2. The Wild Harbor salt marsh (Buzzards Bay, Massachusetts, USA) still harbours residual petroleum from a 1969 oil spill, which released 700 000 L of No. 2 fuel oil. Previous effects have been noted in fiddler crabs and ribbed mussels inhabiting the oiled marsh. 3. Spartina alterniflora biomass was sampled above-and below-ground in elevational transects through areas with different total petroleum hydrocarbon (TPH) content. Further, elevational differences were mapped in oiled and non-oiled locations. 4. Stem density and above-and below-ground biomass decreased in oiled areas. The decreased vegetation biomass led to unconsolidated sediments, increased topographical variation and, ultimately, loss of salt marsh habitat. 5. Four decades after the Florida spill, with only 100 kg of the original 595 000 kg of spilt oil persisting in salt marsh sediment, the effects on large-scale ecosystem functions are still evident. 6. Synthesis and applications . Our results demonstrate specific impacts of residual petroleum on S. alterniflora biomass and coastal erosion. Further, we have defined TPH content thresholds at which to expect long-term ecosystem impacts. The recalcitrant nature of these contaminants and their chronic large-scale ecosystem effects leads to the potential demand for alternative compensation, such as preservation of coastal systems at risk elsewhere.

Effects of residual hydrocarbons on the reed community after 10 years of oil extraction and the effectiveness of different biological indicators for the long-term risk assessments

“…4). Previous field studies indicate that the detrimental effects of elevated soil TPH concentration on biomass continue for several months or decades (Culbertson et al, 2008) after initial contamination. Ji et al (2004) demonstrate experimentally that the addition of soil TPH significantly reduces the aboveground biomass of reeds in the first year but this was reversed during the second year relative to the control (no oil addition).…”

“…This reduction in LAI is due to decreases in the size and number of leaves (Zhang et al, 2007). PH also can inhibit the height (Lin et al, 2002;Peng et al, 2009;Rosso et al, 2005;Zhang et al, 2007), stem density (Culbertson et al, 2008), biomass and coverage (Culbertson et al, 2008;Lin and Mendelssohn, 2012;Peng et al, 2009;Rosso et al, 2005;Zhang et al, 2007) of plants. These tests allow explorations of the underlying mechanisms for the PH effects under controlled conditions, but they are not practical for the analysis and prediction of plant community behavior in all its complexity in field situations (Forbes et al, 2006;van Gestel et al, 2001;Pezeshki et al, 2000;Zhu et al, 2012).…”

“…Increasing oil exploration, manufacture and transportation of petroleum products has resulted in numerous environmental issues (Lin et al, 2002;Peng et al, 2009;Peterson et al, 2003;Ribeiro et al, 2013 a direct toxic effect on most organisms (Lin et al, 2002;Peng et al, 2009;Ribeiro et al, 2013), have long persistence in the environment and long-term adverse effects on ecosystems (Culbertson et al, 2008;Li and Boufadel, 2010;Peterson et al, 2003;Reddy et al, 2002). Furthermore, PH may eventually affect human health (Ha et al, 2012;Lu et al, 2012) and associated activities, such as agriculture (Anoliefo and Vwioko, 1995) and tourism .…”

“…However, few studies have investigated the potential long-term effects of elevated PH levels on plant community in the field (Culbertson et al, 2008;Hester and Mendelssohn, 2000). PH have been found to lower plant community productivity (Kinako, 1981;Mishra et al, 2012;Zhu et al, 2013), simplify their structure (Burk, 1977;Collins et al, 1994;Mendelssohn et al, 1990;Mishra et al, 2012) and reduce their biological diversity (Osuji et al, 2004).…”

Impact of Edaphic Hydrocarbon Pollution on the Morphology and Physiology of Pea Roots (Pisum Sativum L.)

“…In plant tissues, organic pollutants can migrate from roots to leaves, and within the plant organs, they can be modified by conjugation, hydroxylation and by cytochrome containing monooxygenase enzymes (Korte et al, 2000). Plant growth is affected by decrease of biomass in oiled areas (Culbertson et al, 2008). For maize germination and growth in crude-oil polluted soil, the effect is proportional to the concentration of the crude oil in the environment (Ogboghodo et al, 2004).…”