Transcript Oil spills in the marine environment

Oil Spills
Jen Gollehon and
Lindsey Poage
Introduction
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Increasing economic development has caused an increase in
marine transportation of crude oils and offshore production.
First major oil spills:
– 1967, “Torrey Canyon” tanker grounded, releasing
117,000 tons of oil
– 1969, blow-out of offshore platform “Santa Barbara”
released 13,600 tons of oil
Need for international legislation and control of
transportation and offshore production
Increase in research of marine environments, oil and its
affects, methods of clean-up, and prevention.
Types of Oil
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Crude oils: mixtures of hydrocarbons of
varying molecular weights and structures
Refined oils: products of distillation of
crude oil
– includes kerosene, diesel oil, jet fuel,
and lubricating oils
Characteristics of Oils
 Affect the behaviour of oil on water and thus
efficiency of clean up
 Will vary depending on environmental conditions
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Specific gravity
Surface Tension
Viscosity
Flash Point
Solubility
Behaviour of Oil
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Spreading and drifting of oil caused by waves
Evaporation
Dissolution
Dispersion of oil droplets
Photochemical oxidation
Microbial degradation
Absorption onto suspended particulate matter
Ingestion by organisms
Sinking and sedimentation
Input of Oil into Marine
Environment
(estimated million tons per year)
Natural
0.7
Offshore Production
0.05
Transportation
1.47
Atmospheric Deposition
0.3
Wastewaters, Run-off, and
Ocean Dumping
1.18
Significant Spill Causes
Weather
Engine Troubles
Fire Explosion
Oil Transfer
Groundings
Contacts
Collisions
Levels of Biological Effects
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Human hazards through eating contaminated
seafood
decrease of fisheries resources and damage to
wildlife
decrease of aesthetic values due to unsightly
slicks and oiled beaches
modification of marine ecosystems by elimination
of certain species with an initial decrease in
diversity and productivity
modification of habitats, delaying or preventing
recolonisation
Affects on Marine
Environments
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Fish and Crustaceans
– may have oily odor or flavor, becoming unfit for human
consumption
– hydrocarbons accumulate in muscle tissue
– formation of tumors
– resistant and opportunistic species increase
Mammals
– oil adheres to fur, affecting swimming ability and blocks
body orifices, loss of body temp.
– irritates skin and sensitive membranes
– ingestion and inhalation of oil
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Sea Birds
– water proofing and insulation of plumage is destroyed
– inability to fly and/or float in water
– difficulty obtaining food and escaping predators
– irritation of eyes
– susceptible to bacterial and fungal infections
Coral Reefs
– death of fish and invertebrates including lobsters, crabs,
gastropods, bivalves, octopus, sea urchins, sea stars, and
sea cucumbers.
– Becomes barren of sessile invertebrates and algae
Shore
– beaches are covered in an oil slime
– oil is buried in the sedimentation of the beach
– amount of oil on the shore depends on the wave actions
Chemical Response
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Natural Cleansing
– Biodegradation
– Enhanced Biodegradation
Chemical Barriers
Sinking Agents
Sorbents
Chemical Dispersants
Burning
Mechanical Response
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Mechanical containment only work when oil is floating
on the water surface
Booms
Pneumatic Barriers
Trawling
High Pressure Water Jets
Hydraulic Dispersion
Clean-Up
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In Water
– Weir Skimmer
– Sorbent Surface
Skimmers
– Suction Devices
– Centrifugal Devices
– Submersion Devices
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On Shore
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Sand Removal
Manual Clean-up
Sea Water Flushing
Sieving Sand