Transcript OilSpillBiol

Oil Spill Biology
1. Impacts
2. Cleanup
Ned Black, Ph.D.,
CERCLA Ecologist, U.S. EPA Region 9
415-972-3055
[email protected]
1. IMPACTS (aka Ecological
Risk Assessment or
Natural Resource Damage
Assessment)
Stressors
Ecological
Receptors
Measures of
Exposure/
Impact
Unacceptable
Risk/Damage
Contaminants,
e.g., bunker oil
Birds, otters,
fish, eel grass
Evidence there
is or might
be a problem
Someone should
pay for cleanup
or damages
Ecological Risk Assessment Fundamentals
COCs and receptors
present, but COCs not
bioavailable or
concentrations too low
Contaminants
of concern
COCs at demonstrably toxic
concentrations, but exposure
pathway to receptors
incomplete, e.g., Mansfield
Canyon mining district
Measures of
Exposure/
Impact
Potential
Receptors
Potential receptors impacted
by something other than COCs,
e.g. habitat destruction and
industrial contamination along
Gulf Coast
Ecological Receptors
• Charismatic macrofauna
• Eel grass, pickle weed, barnacles, herring
roe
Impacts
• Acute and chronic toxicity of fuel in water column:
mortality to plankton (including larvae of many species);
narcosis effects to juvenile fish at ultra-low concentrations
• Population-level effects: Cosco Busan spill decimated
2007 herring reproduction due to oiling of roe on piers
• Smothering of marsh and tidal plants
• Oil-coated animals: hypothermia, poisoning from ingesting
oil during preening or from eating contaminated food
2. Cleanup (aka
Biodegradation)
• Global carbon cycle: bacteria and fungi
mineralize complex organic molecules
• Bacteria and fungi have been doing this for 4.5
billion years
• Bacteria and fungi are everywhere (including
water puddles inside gas pipelines)
• Bacteria will attach to an oil/water interface and
consume hydrocarbons as they slowly dissolve
into the water
• Dispersing oil into tiny particles speeds this
process
Ripley, M. , Harrison, A. , Betts, W. and Dart, R. (2002),
Mechanisms for enhanced biodegradation of petroleum
hydrocarbons by a microbe-colonized gas–liquid foam.
Journal of Applied Microbiology, 92: 22–31.
Figure 7. (a) Phase contrast (100×); (b)
fluorescence (40×) and (c) confocal
scanning laser (40×) photomicrographs
illustrating the sorption of Acinetobacter
junii (Hex-2) at the gas–liquid interface of
the foam. L, Lamellae; P, plateau border;
B, bacteria; G, gas bubble
Mansfield Canyon Mining District, AZ
Shaft pool