Environmental Impacts of a Major Marine Oil Spill

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. Anns 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 Washingtons
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.
12
Quantities of Oil Spilled 1970 - 1999
13
Spill Trend - 1970 to 1999
14
Oil Barge Tanker Routes
Exxon Valdez
Nestucca
15
The Great Circle Route - Major Vessels
Kuroshima
Tenyo Maru
New Carissa
16
Relative Spill Risk - British Columbia
Low Probability, High Consequences
Risk Function of Probability Consequences
Oil Tankers (e.g. US TAPS)
Bulk Oil Barges
Major Vessels (e.g.Cargo, Container, Bulk
Carriers)
Fuel Handling Facilities
High Probability, Low Consequences
17
Spill Scenario 1 - Outer Juan de Fuca Strait
18
Spill Scenario 2 - Rosario Strait
19
Fate and Effect of Spilled Oil
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 spills 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
Surface oiling a study sites in Prince William
Sound
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.
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
oceans 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 Columbias 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
37
Coastal Mapping
Shoreline Oil Sensitivity Mapping ensures the
most environmentally-sound and effective methods
are used. Based on technical, not political
evaluations
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.