O
OIL POLLUTION
Michael J. Kennish
Department of Marine and Coastal Sciences,
School of Environmental and Biological Sciences,
Rutgers University, New Brunswick, NJ, USA
Synonyms
Crude oil; Petroleum
Definition
Crude oils consist of complex mixtures of hydrocarbon
and nonhydrocarbon compounds, and they vary considerably in their chemical composition and physical properties. Discharges, leakages, or spills of oil can cause
serious impacts in estuarine and marine environments.
Composition
Hydrocarbon compounds account for more than 75 % of
most crude oils, although nonhydrocarbon components
(e.g., compounds containing oxygen, nitrogen, sulfur,
and metals such as copper, iron, nickel, and vanadium)
can predominate in heavy crude oils. There are many toxic
substances in crude oils including, but not limited to, benzene, toluene, xylene, phenols, and carboxylic acids.
Hence, oil spills and leakages into estuarine and marine
environments can pose a serious threat to biotic communities and habitats in these environments, particularly those
in the coastal zone (Kennish, 2001; Cormack, 2010).
Crude oils are composed of four major classes of
hydrocarbons: (1) straight-chain alkanes (n-alkanes or
n-paraffins), (2) branched alkanes (isoparaffins),
(3) cycloalkanes (cycloparaffins), and (4) aromatics. The
lower-molecular-weight compounds in each class dominate in these oils (Kennish, 1997). Several important
physical-chemical processes alter the composition and
toxicity of oil in estuarine and marine environments
through time. These include evaporation, photochemical
oxidation, emulsification, and dissolution. Marked
changes in composition occur during the first 24–48 h of
an oil spill when the more toxic and volatile components
are lost to evaporation and dissolution effects.
Anthropogenic effects
Most oil inputs from human activities to estuarine and
marine environments result from marine transportation
(deballast and tanker accidents), leakages of fixed installations (e.g., coastal refineries, offshore production facilities, and marine terminals), municipal and industrial
wastewaters, urban and suburban runoff, and atmospheric
deposition (Kennish, 1997; Kennish, 2001). A number of
factors determine the severity of oil impacts on organisms
and habitats in these environments: (1) amount of the oil;
(2) composition of the oil; (3) form of the oil (i.e., fresh,
weathered, or emulsified); (4) occurrence of the oil (i.e.,
in solution, suspension, dispersion, or adsorbed onto particulate matter); (5) duration of exposure; (6) involvement
of neuston, plankton, nekton, or benthos; (7) juvenile or
adult biotic forms exposed; (8) previous history of pollutant exposure; (9) season of the year; (10) temperature,
salinity, and other physical-chemical variables; (11) type
of habitats impacted; and (12) cleanup methods (Clark,
1992; Doerffer, 1992; Kennish, 1992; Kennish, 2001).
Polluting oil may not only be directly toxic to aquatic
organisms, but also can increase their mortality by smothering or suffocating them. Both lethal and sublethal
effects can devastate impacted populations. Therefore,
oil spills and other releases of oil to estuarine and marine
environments must be carefully monitored and quickly
remediated (Kim et al., 2010).
Oil spills tend to sink through time in the marine hydrosphere as the density of the oil increases. Hence, sedimentation of oil on the seafloor poses a significant long-term
M.J. Kennish (ed.), Encyclopedia of Estuaries, DOI 10.1007/978-94-017-8801-4,
© Springer Science+Business Media Dordrecht 2016
OIL POLLUTION
Michael J. Kennish
Department of Marine and Coastal Sciences,
School of Environmental and Biological Sciences,
Rutgers University, New Brunswick, NJ, USA
Synonyms
Crude oil; Petroleum
Definition
Crude oils consist of complex mixtures of hydrocarbon
and nonhydrocarbon compounds, and they vary considerably in their chemical composition and physical properties. Discharges, leakages, or spills of oil can cause
serious impacts in estuarine and marine environments.
Composition
Hydrocarbon compounds account for more than 75 % of
most crude oils, although nonhydrocarbon components
(e.g., compounds containing oxygen, nitrogen, sulfur,
and metals such as copper, iron, nickel, and vanadium)
can predominate in heavy crude oils. There are many toxic
substances in crude oils including, but not limited to, benzene, toluene, xylene, phenols, and carboxylic acids.
Hence, oil spills and leakages into estuarine and marine
environments can pose a serious threat to biotic communities and habitats in these environments, particularly those
in the coastal zone (Kennish, 2001; Cormack, 2010).
Crude oils are composed of four major classes of
hydrocarbons: (1) straight-chain alkanes (n-alkanes or
n-paraffins), (2) branched alkanes (isoparaffins),
(3) cycloalkanes (cycloparaffins), and (4) aromatics. The
lower-molecular-weight compounds in each class dominate in these oils (Kennish, 1997). Several important
physical-chemical processes alter the composition and
toxicity of oil in estuarine and marine environments
through time. These include evaporation, photochemical
oxidation, emulsification, and dissolution. Marked
changes in composition occur during the first 24–48 h of
an oil spill when the more toxic and volatile components
are lost to evaporation and dissolution effects.
Anthropogenic effects
Most oil inputs from human activities to estuarine and
marine environments result from marine transportation
(deballast and tanker accidents), leakages of fixed installations (e.g., coastal refineries, offshore production facilities, and marine terminals), municipal and industrial
wastewaters, urban and suburban runoff, and atmospheric
deposition (Kennish, 1997; Kennish, 2001). A number of
factors determine the severity of oil impacts on organisms
and habitats in these environments: (1) amount of the oil;
(2) composition of the oil; (3) form of the oil (i.e., fresh,
weathered, or emulsified); (4) occurrence of the oil (i.e.,
in solution, suspension, dispersion, or adsorbed onto particulate matter); (5) duration of exposure; (6) involvement
of neuston, plankton, nekton, or benthos; (7) juvenile or
adult biotic forms exposed; (8) previous history of pollutant exposure; (9) season of the year; (10) temperature,
salinity, and other physical-chemical variables; (11) type
of habitats impacted; and (12) cleanup methods (Clark,
1992; Doerffer, 1992; Kennish, 1992; Kennish, 2001).
Polluting oil may not only be directly toxic to aquatic
organisms, but also can increase their mortality by smothering or suffocating them. Both lethal and sublethal
effects can devastate impacted populations. Therefore,
oil spills and other releases of oil to estuarine and marine
environments must be carefully monitored and quickly
remediated (Kim et al., 2010).
Oil spills tend to sink through time in the marine hydrosphere as the density of the oil increases. Hence, sedimentation of oil on the seafloor poses a significant long-term
M.J. Kennish (ed.), Encyclopedia of Estuaries, DOI 10.1007/978-94-017-8801-4,
© Springer Science+Business Media Dordrecht 2016