1. Environmental Impacts of
a Major Marine Oil Spill
Prepared by
Stafford Reid
Environmental Emergency Planner
Enforcement and Environmental
Emergencies Branch
BC Ministry of Water, Land and
Air Protection
2. Presentation Outline
Major Marine Oil Spill Incidents
Oil Spill Risk In British Columbia
Oil Types and Characteristics
Oil Behaviour (Fate and Effects)
Oil Impacts
A Case Study - Exxon Valdez
Coastal Inventory and Oil Sensitivity Mapping
Shore Cleanup and Assessment
3. Torrey Canyon - England
(March 1967)
A Liberian-registered
tanker en route from the
Persian Gulf was stranded
by an error in ship
manoeuvring, releasing
93,000 tonnes of crude
oil. Contaminated 300
kilometres of both
England and France.
4. Amoco Cadiz - France
(1978)
A Liberian-registered
tanker en route to
England grounded on
a reef off the coast of
Brittany (France) and
releasing 260,000
tonnes of crude oil.
Contaminated 400 km
of coast. Took six
months to collect and
dispose of the drifting
oil.
5. Sea Empress - Wales
(February 15, 1996)
The single-hulled
Liberian oil tanker ran
aground on St. Ann’s
Head at the mouth of
Milford Haven estuary,
Wales, rupturing several
tanks. It released 72,000
tonnes of light North
Sea Crude.
6. Braer - Scotland
(January 5, 1993)
An 18 years old, American
owned, but Liberian-
registered, oil tanker that
ran aground at Garth Ness
in the Shetlands in severe
weather conditions. Cause
was complete engine
failure. Spilled its entire
cargo of 85,000 tonnes of
North Sea Crude.
7. Exxon Valdez - United States
(March 24, 1989)
A US-flagged tanker en
route to Long Beach
California wrecked on
Bligh Reef in Prince
William Sound, Alaska
due to Captain error.
Eight of the eleven tanks
damaged, releasing
41,000 tonnes of Alaska
Northslope Crude Oil.
Contaminated 1,900
kilometers of coast.
8. Nestucca - United States (December 23, 1988)
The fuel barge Nestucca and
its tender tug Ocean Service
collided of the mouth of
Grays Harbour, State of
Washington. An estimated
890 tonnes of heavy Bunker
C oil spilled from the
ruptured barge. The oil
drifted past Cape Flattery and
stranded along the west coast
of Vancouver Island, British
Columbia.
9. Tenyo Maru - United States
(July 22, 1991)
Off the entrance to the Juan de Fuca Strait,
the Japanese fishing vessel Tenyo Maru and
Chinese freighter Tuo Hai collided. The
Tenyo Maru sank, releasing 365 tonnes of
bunker fuel. The slick travelled southwest to
the State of Washington’s Cape Flattery
10. New Carissa - United States
(February 3, 1999)
A Japanese-owned, but
Panamanian-flagged bulk
carrier on its way to Coos
Bay, Oregon (US) lost
anchor during storm
conditions and grounded
outside of Coos Harbour. It
held 1,490 tonnes of bunker
fuel, spilling 268 tonnes
when it broke in half.
11. Kuroshima - United States
(November 26, 1997)
A 368 foot seafood
freighter broke away
from its anchorage
during a severe storm
and ran aground spilling
145 tonnes of Bunker C
oil. Contaminated
approximately 10
kilometres of shoreline
of Summer Bay on the
Aleutian Island of
Unalaska.
15. The Great Circle Route
- Major Vessels
New Carissa
Kuroshima
Tenyo Maru
16. Relative Spill Risk - British Columbia
Oil Tankers
(e.g. US TAPS)
Risk = Function of Probability &
Consequences
Major Vessels (e.g.Cargo,
Container, Bulk Carriers)
Bulk Oil Barges
Fuel Handling Facilities
High Probability, Low
Consequences
Low Probability, High
Consequences
20. Fate & Affect by Oil Type
DENSITY EXAMPLES
Group I less than 0.8 Gasoline, Kerosene
Group II 0.8 - 0.85 Gas Oil, Abu Dhabi Crude
Group III 0.85-0.95 Arabian Light Crude, North Sea Crude
Group IV greater than 0.95 Heavy Fuel Oil, Venezuelan Crude Oils
21. Impacts of a Major Oil Spill
Destroys Marine Life
Destabilizes Marine
Communities
Degrades Shore Amenities
Harms Economic Activities
Impacts Human Welfare
22. Destroys Marine Life
Physical contamination and smothering are primary
mechanisms that adversely affecting marine life -
particularly inter-tidal organisms. Oil can also change the
physical characteristics of a habitat.
Clean-up activities can add to these effects by crushing,
removing, and damaging marine life.
Birds and mammals suffer the greatest acute impact when
they meet the oil/water interface and become contaminated.
Reduction in thermal capability, and directed toxicity from
fumes and ingestion are the greatest causes of mortality.
23. Destabilizes Marine Communities
and Populations
Marine communities, such as planktonic waters,
wetlands (estuaries/marshes), kelp-beds and mud-
flats, and marine populations such as seabirds, seals
sea otters, and whales have variable resiliency to oil
spills - from highly tolerant (plankton, kelp beds) to
very intolerant (estuaries and sea otters).
Impacts to communities and populations are very
difficult to measure due to lack of scientific methods
to measure, long-term, sub-lethal, and chronic
ecological impacts
24. Degrades Shore Amenities
Contamination of coastal amenity areas is a common
feature with many marine oil spills, leading to public
disquiet and concern regarding impacts to boating, sun-
bathing, swimming, angling and other recreational pursuits.
The prevailing question is how much and how long of an
impact? The degree of impact to recreation is largely based
on the season it occurred.. Summer being the highest impact
period due to recreation and tourism.
25. Harms Economic Activities
Economic activities that can be adversely affected by
an oil spill include: tourism, hotel and restaurant
businesses, dive and fishing charters, rentals, marina
operations. There can also be direct impacts to
commercial fishing and aquaculture due to closures or
concerns about tainted products.
The impacts to a coastal communities economic
activities can be accentuated by media press, beyond
the actual impacts to the recreational and commercial
opportunities.
26. Impacts Human Welfare
A spill’s impact to human welfare is often under-rated.
Coastal communities, and public in general, are deeply
passionate about a safe, clean marine environment. There is
no tolerance for accidental spills of oil of any quantity. As
such a marine oil spill accentuates this passion, often
beyond rationale thinking.
During an incident, public stress and anxiety prevail over
the long-term economic uncertainty of lost welfare. In
addition, a large influx of spill money can divide a
communities from those the volunteer from their
“hearts” and those the offer their services for a “fee”.
27. Spill Impact Recovery
The recovery of the marine
environment from the effects of
a spill is generally thought to be
“a return to the precise
conditions that preceded the
oil spill”. However, this is very
unlikely to happen. As such,
the measurement of spill
recovery is based on a
comparison of unoiled sites
with oiled sites of similar
ecological characteristics.
28. A Case Study - Exxon Valdez
This 1989 crude oil spill occurred in the most biological
active season
More than 1,900 kilometres of coast oiled
3,500 to 5,500 sea otter died
200 harbour seals
144 species of dead birds collected
Estimated bird loss ranges from 260,000 to 580,000
60 to 70% colony reduction in Common and Thick-
billed Murres
29. Case Study - Oil Reduction in
Intertidal Shorelines
Intertidal habitats of the Prince William Sound have shown
surprisingly good recovery. Many shorelines that were heavily
oil and then cleaned now appear much as they did before the
spill. There are, however, still oil vestiges 10 years later.
Surface oiling a study sites in
Prince William Sound
30. Case Study - Remaining Impacts to
Intertidal Habitats
Remaining impacts include:
some deeply penetrated oil continue to leach from
a few beaches, and weathered remnants of oil in a
few sites
some intertidal animals, such as mussels, are still
contaminated
some rock sites stripped by aggressive (e.g. high-
pressure, hot-water) cleaning are still bare
a few rich clam beds that suffered high mortality
have not fully recovered.
31. Case Study - Remaining Impacts to Wildlife
Though a high number of
individual animals may have
been killed, the actual initial
impacts to communities
(populations) of salmon, sea
otters, harbour seals and sea bird
was low. Indications show that
wildlife species populations
have recovered within their
natural range of variability.
32. Case Study - Restoration Focus
The marine environment with its natural resiliency and
ability to recover required little work in restoration, beyond
initial cleaning. The bird and wildlife populations are more
threatened by upland activities such as logging, which
destroyed Marbled Murrelet nesting areas, bear foraging
sites, and salmon habitats.
Settlement funds - billions of dollars - enable purchase of a
million acres of forest lands to ensure a sustainable
environment. These purchases recognized that one can't
draw a line at the ocean’s edge.
33. Case Study - Some Lessons Learned
Natural flushing action of waves
and storms is far more efficient
and better in restoration than
mops, hoses, and rakes.
Wildlife rescue and rehabilitation
efforts had a marginal beneficial
effect on the recovery of bird and
mammal populations.
Conventional wisdom is that
habitat protection is a better cure
than damage mitigation, no
matter how extensive or tender.
34. Case Study - Conclusions
From an ecological perspective, the impacted area of the
Prince William Sound from the Exxon Valdez has shown
surprising resiliency - an ability to return to its natural state
within the range of natural variability. There are still
environmental scarring.
From a social perspective, the impact of the Exxon Valdez
oil spill on those people who lived and experienced the
event remains as fresh in their minds as the day it happened.
People still hurt.
In conclusion, the environment has a greater resiliency to an
oil spill than people.
35. British Columbia’s Ecological Approach to
Marine Oil Spill Management
The Exxon Valdez as well as many other major oil spills
has enable British Columbia to learn from the experiences
of what to do, or more importantly what not to do.
These lessons are reflected in two main areas that the
Province focuses on:
•Coastal Inventory and Shoreline Oil Sensitivity
Mapping
•Shore Cleanup and Assessment
36. Coastal Inventory and Shoreline Oil
Sensitivity Mapping
British Columbia has one
of the most extensive and
sophisticated coastal
inventory and shoreline
sensitivity mapping
program in the world.
Red = High Oil
Sensitivity
38. Shoreline Cleanup and Assessment
When a spill occurs, Canada utilizes the Shoreline Cleanup and
Assessment Team (SCAT) process adopted from Alaska to determine
when and how each individual shoreline will be cleaned based on
geomorphological, ecological and archaeological factors.
