NB This worst case scenario marine oil spill for the Queen Charlotte Basin was part of Dr. Gerald Graham's 2004 Submission to the Royal Society of Canada Expert Panel on the British Columbia Offshore Oil and Gas Moratorium, pp. 7-12. It is worth noting that the scenario Dr. Graham created was also included as part of the Written Evidence of the Intervenor, Coastal First Nations, to the Enbridge Northern Gateway Joint Review Panel, Dec. 21, 2011, pp. 62-66. Here is the scenario:
"Our scenario involves a tanker spill of the same order as the Exxon Valdez spill, in the middle of Queen Charlotte Sound. We are attempting to determine whether a credible response can be mounted there, and what might be the consequences for the environment, economy, etc. if the response was either too weak or too late.
For the purposes of our simulation, the spill has occurred in the year 2009, five years after a sensitivity atlas was completed for the Central Coast; in other words, we know all we need to know about sensitive resources, hotspots, etc. Assume that at 4 AM on March 6, a total of 240,000 barrels of Athabasca heavy, synthetic crude oil accidentally releases from the holds of a stricken tanker in the Sound. The tanker suffered from structural failure after being hit by a giant, 30-metre wave during a marine bomb.[22]
Using ADIOS2, a spill weathering model developed by NOAA and available to users free of charge off of their website[23], if we assume that the wind speed is 25 knots from 224 degrees at the time of the spill, that the sea temperature is 4 degrees Celsius, and that the current is 2 knots towards 37 degrees, then of the original 240,000 barrels spilled, 40,000 barrels will disperse, and a further 40,000 barrels will have evaporated after four days. Thus, one will be left with 160,000 barrels of the original cargo to recover and/or clean up. However, the effect of emulsification will mean that this 160,000 barrels will have actually turned into an oil-water mixture of perhaps twice to three times that amount, compounding the response challenge and increasing the potential for negative impact.
Let’s assume that the nearest spill response depots are located at Bella Bella and Kitimat on the mainland, as well as Port Hardy on Vancouver Island. The resources of these centres would immediately be called upon, as well as those of the rest of Canada, the United States, and probably the international community, e.g. Oil Spill Response Limited in Southampton, England, and East Asia Response Limited in Singapore. However, given the standard weather conditions for this time of year, the relatively short days, the distance from the spill site, and the time required to organise and mount a response effort, it could easily be 48 to 72 hours before anyone is in a position to start containing and recovering oil off the surface, with the appropriate vessels, storage tanks, booms, skimmers, etc.[24]
Once in place, the standard response option of containment and recovery at sea, using mechanical equipment will probably not work; poor operating conditions could prevent the effective deployment of these devices for days, if not weeks, if the following figures for wintertime wind speeds in Hecate Strait are any indication[25]:
Average wind velocities equal or exceed the specification for standard types of mechanical equipment ( e.g. booms and skimmers ) in each month from December through March.
In the meantime, most of what is going to happen to the oil, e.g. evaporation, dispersion and emulsification, has already happened in that brief, initial period before the response vessels actually arrive on the scene. This severely limits the response options, because burning the oil at sea or using dispersants can typically only be done during a brief ‘window of opportunity’ and assuming the environmental conditions are conducive to such options. Unfortunately, at this time of year normal conditions are pretty dreadful, thereby eliminating these two options. Dispersants are an option Strong favours, without taking into account the limitations of its application[26]. Bornhold and Harper note the following:
“Dispersant use within 24 hr ( sic ) of the spill represents the only mitigation strategy. However, having a pre-approved dispersant application plan cannot be assumed as dispersant use is highly controversial. At present there is no pre-approved use of dispersants anywhere in Canada.”[27]
Where the oil will end up is anyone’s guess; this would depend in part on the sea temperature, wind speed and direction, tidal current speeds and direction, etc. We do, however, have a rough idea as to surface circulation in the Sound and off the central coast. Generally speaking, not accounting for tides, oil spilled in Hecate Strait and Queen Charlotte Sound should tend to drift in a southerly direction in the summer, and in a northerly direction in the winter. As a rule of thumb, oil on the surface will drift at the rate of 3 % of wind speed and 100% of current speed.
As the oil follows its trajectory, the response authorities would no doubt be well into the shoreline protection and cleanup phase of operations, conducting assessments of impacted shoreline, and directing the appropriate equipment and resources to sites identified in advance for priority treatment. Fishing vessels would also be called up to participate in the response effort, as per the contingency plan. Unfortunately, as mentioned earlier, worldwide experience demonstrates that even if things go relatively well, on average only 10-15% of oil spilled at sea is ever recovered; the rest either evaporates, disperses, dissolves or ends up on the shore somewhere. The Prestige spill off the coast of Spain had an exceptional ‘recovery rate’ of approximately 40% of the oil scooped off the surface; half of this amount was picked up by response vessels using conventional techniques such as sweeping arms, and half by fishing vessels using improvised techniques.
Adding to the response challenge would be the enormous logistical problems faced in the region. Even at the best of times, there are very few roads, airports, ports or other staging areas from which to launch a coordinated response. At least fifty percent of the central coast consists of rocky shoreline; in high energy environments the oil should naturally degrade as wind and waves combine to break it down eventually. This is what happened in the case of the Braer spill off the Shetlands in 1993.
However, in low energy rocky shoreline environments which, according to Bornhold and Harper, comprise about 35% of the shoreline of the North Coast, the oil could remain there for months or years[28]. Another 35% of the shoreline, or 6000 kms, consists of “…low energy, bedrock shoreline that will have moderate oil residence periods”[29]. What oil is recovered may have to be stored in vessels or barges and hauled away by sea for eventual recycling or disposal, as there would be little opportunity to bring the oil ashore and haul it away by tank truck.
In the meantime, the marine environment could suffer in many ways from the effects of oil, as the following quote attests:
“Oil spills could affect all species resident, reproducing, or feeding in intertidal areas and salt marshes. This would include salmon, herring, abalone, sea urchins, sea cucumbers, clams, and sea and land birds and some marine mammals. Spills could affect all plants and animals in the surface and upper layer of the ocean, including most larval fish and planktonic eggs, and marine birds and mammals.”[30]
The Alan Wood report goes on to state: “Grazing herbivores such as sea urchins, and probably abalone, limpets, chitons, and snails, are highly impacted by oil”[31], and that:
“Intertidal feeders such as clams, rock scallops, and mussels are impacted by oil. Clams are impacted by oil settling into sand and gravel in their habitat. Beyond mortality, there is a long-term contamination and tainting of mussels”[32].
Harbo estimates that there are 7000 invertebrate species ( sponges, crab, shrimp, sea stars, etc. ) in British Columbian waters, plus 400 fishes, 200 marine birds and 30 types of marine mammals. In addition, there are 640 species of seaweeds and seagrasses in this province.[33]. Many of these species call the waters of the Queen Charlotte Basin home. Thus, the Strong report, which puts the total number of species in the region at between 500 and 1000, would seem to seriously underestimate the biodiversity of the area, and thus the potential impact of a major spill on marine life.[34]
Rather than provide a detailed summary of the species that spills may impact off the Central Coast, such as the Goose Island sea otter population, or the sponge reef colonies, let us highlight the potential impact of oil on just two species in the nearshore area – sand lance and sea mussels.
Sand lance
As Alan Wood Consulting point out in an annex to the Strong report, this small fish, which inhabits shallow water, could be vulnerable to oil spills[35] ( p. 105 ).
“In the Queen Charlotte Basin, sand lance is preferred food for rock sole, petrale sole, pacific cod, chinook, coho, lingcod, halibut and many other fish species and some seabirds.”[36]
Elsewhere, it is reported that in Puget Sound at least
“…35% of juvenile salmon diets are composed of sand lance. Juvenile Chinook salmon depend on sand lance for 60% of their diet. Minke whales, other marine mammals, and many species of seabirds also prey on sand lance”[37].
In short, destroy the sand lance and you could end up destroying salmon populations in the area. Destroying the salmon could produce a domino effect, imperilling not just the marine environment but the coastal forest ecosystem as well.
Sea mussels
As the Strong report says:
“The interaction between species are very important to the overall functioning of the ecosystem with some species ( the keystone species ) playing a more critical role. Any factor that has a negative impact on the keystone species would be expected to have profound impacts on the entire ecosystem.
For example, sea mussels form densely aggregated beds from the upper intertidal to subtidal depths. They provide a protective matrix for a very complex community of more than 300 different species. They are long-lived, and species richness increases with increasing mussel bed age and thickness. However, as filter feeders, mussels are very sensitive to oil contamination and are known to readily accumulate Polycyclic Aromatic Hydrocarbons (PAHs) in areas of urban run-off and oil spills.
Consequently, the exposure of sea mussels to oil as the result of frequent small or catastrophic spills would have serious implications for the entire food web, including fish, sea-birds and marine mammals”.[38]
In other words, a spill of 240,000 barrels could wreak havoc on the marine environment of the Central Coast, and there might be very few options for responding to it at certain times of year."