With climate change, the oceans are becoming more acid and that is a threat to the dungeness crab, according to a study by the US National Oceanic and Atmospheric Administration.
The study says ocean acidification expected to accompany climate change may slow development and reduce survival of the larval stages of Dungeness crab.
The dungeness crab is a key component of the Northwest marine ecosystem and vital to fishery revenue from Oregon to Alaska.
The research by NOAA Fisheries’ Northwest Fisheries Science Center in Seattle indicates that the declining pH anticipated in Puget Sound could jeopardize populations of Dungeness crab and put the fishery at risk. The study was recently published in the journal Marine Biology.
Ocean acidification occurs as the ocean absorbs carbon dioxide from the combustion of fossil fuels. Average ocean surface pH is expected to drop to about 7.8 off the West Coast by 2050, and could drop further during coastal upwelling periods.
Dungeness crab is the highest revenue fishery in Washington and Oregon, and the second most valuable in California, although the fishery was recently closed in some areas because of a harmful algal bloom. The Dungeness crab harvest in 2014 was worth more than $80 million in Washington, $48 million in Oregon and nearly $67 million in California
“I have great faith in the resiliency of nature, but I am concerned,” said Jason Miller, lead author of the research, which was part of his dissertation. “Crab larvae in our research were three times more likely to die when exposed to a pH that can already be found in Puget Sound, our own back yard, today.”
Scientists collected eggs from Dungeness crabs in Puget Sound and placed them in tanks at the NWFSC’s Montlake Research Laboratory. The tanks held seawater with a range of pH levels reflecting current conditions as well as the lower pH occasionally encountered in Puget Sound when deep water wells up near the surface. Larvae also went into tanks with the even lower-pH conditions expected with ocean acidification.
“The question was whether the lower pH we can expect to see in Puget Sound interferes with development of the next generation of Dungeness crab,” said Paul McElhany, a NOAA Fisheries research scientist and senior author of the paper. “Clearly the answer is yes. Now the question is, how does that play out in terms of affecting their life cycle and populations overall?”
Larvae hatched at the same rate regardless of pH, but those at lower pH took longer to hatch and progressed through their larval stages more slowly. Scientists suggested that the lower pH may reduce the metabolic rate of embryos. That could extend their vulnerable larval period, or could jeopardize the timing of their development in relation to key food sources, researchers suggested.
Larval survival also dropped by more than half at lower pH. At pH 8.0, roughly equivalent to seawater today, 58 percent of the crab larvae – called zoeae – survived for 45 days. At pH 7.5, which sometimes occurs in Puget Sound now, survival was 14 percent. At pH 7.1, which is expected to roughly approximate the pH of water upwelling on the West Coast with ocean acidification, zoeae survival remained low at 21 percent.
“Areas of greatest vulnerability will likely be where deep waters, naturally low in pH, meet acidified surface waters,” such as areas of coastal upwelling along the West Coast and in estuary environments such Hood Canal, the new study predicts.
Eel grass is not a seaweed but a flowering plant that migrated to the sea, say scientists who have now mapped the eel grass genome. The study also shows that eel grass ( Zostera marina) is crucial in absorbing carbon dioxide in the soft sediments of the coasts.
Eel grasses form a carbon dioxide sink: “they store more carbon than tropical forests,” says Jeanine Olsen of the University of Groningen in the Netherlands who led the study.
Coastal sea grass ecosystems cover some 200,000 square kilometers, the study says. Those ecosystems account for an estimated 15 per cent of carbon fixed in global ocean, and also impact sulphur and nitrogen cycles.
The scientists argue that since sea grasses are the only flowering plants to have returned to the sea that is the most extreme adaptation a terrestrial (or even freshwater) species can undergo.
The science team says the Zostera marina genome is “an exceptional resource that supports a wide range of research themes, from the adaptation of marine ecosystems under climate warming and its role in carbon burial to unraveling the mechanisms of salinity tolerance that may further inform the assisted breeding of crop plants.”
Sea grasses form the backbone of one of the most productive and biodiverse ecosystems on Earth, rivaling coral reefs and rain forests in terms of the ecosystem services they provide to humans.
Sea grass meadows are part of the soft-sediment coastal ecosystems found in all continents, with the exception of Antarctica. They not only form a nursery for young fish and other organisms, but also protect the coastline from erosion and maintain water clarity. ‘
The study, which sequenced the genome of the eel grass taken from the Archipelago Sea off Finland. published today, in the journal Nature, is the work of an international consortium of 35 labs, most of them in Europe, working with researchers from the U.S. Department of Energy Joint Genome Institute.
The study showed that eel grasses are completely submerged marine flowering plants, called by science angiosperms. It shows that eel grass is a member of the ancient monocot family.
The monocots include about 60,000 species, flowering plants that first appear above the soil as a single leaf. They include orchids, “true grasses,” as well as rice, wheat, maize and “forage grasses” such as sugar cane, and the bamboos. According to Wikipedia, other economically important monocot crops include palms bananas , gingers, onions, garlic, lilies, daffodils, irises, amaryllis, bluebells and tulips.
Zostera marina is the first marine flowering plant have its genome fully sequenced. As well as finding the eel grass’s genetic ancestors the researchers were interested in understanding how the plant–and by extension other plants in the ecosystem–adapt to climate change.
As it adapted to an underwater, coastal lifestyle, eel grass gained genes that allowed it to live in saltwater but lost genes involved in traits associated with land-based plants.
Olsen called this “arguably the most extreme adaptation a terrestrial (and even a freshwater) species can undergo.”
What she describes as the “use it, lose it, or change it” scenario, eelgrass modified its cell walls. The eel grass cell wall is very different from normal plant cell walls and more like that of sea algae, similar to the cell in seaweeds. The eel grass has lost genes associated with light-sensing, pollination and regulation of internal water balance.
Eel grass lost its stomata (which are used by land plants to ‘breathe’) but also all of the genes involved in stomatal differentiation. “The genes have just gone, so there’s no way back to land for sea grass,” Olsen says. Sex is entirely underwater involving long naked sperm filaments especially adapted for underwater fertilization of the tiny flowers.
The team compared the eel grass genome to duck weed, one of the simplest flowering plants and Zostera marina’s closest sequenced relative. They noted differences in genes related to cell wall structure due to adaptations to freshwater or terrestrial conditions. For example, plants such as duckweed have seemingly lost genes that help plants retain water in the cell wall, while eel grass has regained these genes to better deal with osmotic stress at low tide.
“They have re-engineered themselves,” said Olsen of the changes affecting the eelgrass cell walls. “Crop breeders may benefit from lessons on how salt tolerance has evolved in these plants.”
With Zostera marina meadows stretching from Alaska to Baja California, and from the White Sea to southern Portugal, Olsen noted that these ecosystems afford researchers “a natural experiment to investigate rapid adaptation to warmer or colder waters, as well as to salinity tolerance, ocean acidification and light.”
Eel grass endangered
Jeremy Schmutz, head of the US Department of Energy’s genetic plant program, emphasized that while eel grasses are key players in coastal marine ecosystem functions and considered the “lungs of the sea,” they are also endangered. “There are estimates that nearly a third of the eel grass meadows worldwide have been destroyed by runoff into the ocean,” he said, “reducing their potential capabilities as carbon sinks. Thus, studying the adaptive capacity of eel grass is urgent to assist conservation efforts.”
An overarching question for Olsen’s team is how quickly eel grass can adapt to rapid climate change. The fact that Zostera marina grows along the coastline from Portugal to Scandinavia is being used as a natural experiment to investigate adaptation to warmer or colder water, as well as to salinity, ocean acidification and light.
That’s one of the predictions from a new study from the University of British Columbia, looking at the future of the fishery on the coast.
The study concentrates on the First Nations fishery and warns that aboriginal people could face a catastrophic decline in the harvest of traditional species, especially salmon and herring roe on kelp over the next thirty years, a decline that will also have an equally devastating effect on commercial and recreational fishing.
The main cause of the decline is climate change and the warming of the coastal waters. The study projected “modest to severe declines in catch potential” for all current commercial fisheries along the coast.
The study says that for the First Nations the between $28 million to $36 million in revenue they got from fishing between 2001 and 2010 could fall by up to 90 per cent depending on how the climate changes.
One scenario calls for a decline of up to 40 per cent in chinook and pink salmon.
If there is any good news, if you can call it that, the decline will be not as bad in northern coastal waters as it will be the warmer waters near the Lower Mainland and southern Vancouver Island. The range of some species, including salmon, herring, halibut and possibly oolichan will move to farther north along the BC Coast and into Alaskan waters.
That means in time the warming waters will also encourage an increase in other species, including sardines and some clams.
The changing oceans mean that “an increase in the relative abundance of warmer-water species was projected to lead to new or increased opportunities for commercial harvests by 2050.”
The study is urging the First Nations and other stakeholders in the British Columbia fishery to start long term planning immediately to anticipate changes in the coming decades.
The team of scientists led by Lauren Weatherdon, a graduate student at UBC, noted that while previous studies have looked at the impact of climate change on large-scale commercial fisheries, “few efforts have been made to quantitatively project impacts on small-scale subsistence and commercial fisheries that are economically, socially and culturally important to many coastal communities.”
The study was conducted in cooperation with the BC First Nations Fisheries Council and looked its seven coastal administrative regions “forming a sample of groups with diverse marine resources, geographical locations, territorial sizes, and treaty statuses.”
Within those regions 16 First Nations participated in the study, some under their treaty councils, including the Council of the Haida Nation, the Tsimshian Nations Treaty Society (including the Gitga’at at Hartley Bay and the Kitselas and Kitsumkalum near Terrace) and the Maa-nulth First Nations. The Heiltsuk First Nation at Bella Bella participated as an independent group.
The FNFC’s administrative regions intersect with five distinct ecological regions: the North Coast, comprising the Hecate Strait and Dixon Entrance; Haida Gwaii, which includes the waters surrounding the islands; the Central Coast, including Queen Charlotte Sound, Queen Charlotte Strait, and the southern tip of Hecate Strait; the Strait of Georgia; and the west coast of Vancouver Island (WCVI) .
The study says First Nations are likely to be exposed to different climate-related impacts on fisheries due to the differing ecological and biogeographical characteristics of these regions and to differing traditional and commercial harvests.
The study used a “dynamic bioclimate envelope” computer model to look at the changes to the distribution and relative abundances of the BC coastal species under two climate change scenarios, a high greenhouse gas model where society can’t curb emissions and a low greenhouse gas emission scenarios, depending on how society is able to curb the increase.
The study looked at ocean properties—including sea surface temperature, sea bottom temperature, salinity, oxygen concentration, surface action, and net primary production—using data from the US National Ocean and Atmospheric Administrations’ climate-related earth system model.
Climate change will mean that current species on the BC coast will “shift polewards.”
The study showed that by 2050, there could be declines in 87 of the 98 species in the study.
Greater losses in what the study calls “species richness” is likely to occur towards the southern coast of British Columbia, falling primarily between 48°N and 51°N. But, overall, species richness along coastal BC will continue—only with different species.
Most significantly the study projects a decline in the overall salmon catch from 17.1 per cent to 29.2 per cent, depending on the region and climate.
All aspects of the herring fishery, including roe herring, spawn-on-kelp, and the food and bait fishery could decline between 28.1 per cent and 49.2 per cent depending on the region.
The future of the oolichan is the most uncertain. One of the models studied projected a further 37.1 per cent decline in the oolichan, while other models called for for a decline between 5 per cent and 6.8 per cent. That will depend on how well, the oolichan already threatened in most regions of British Columbia are able to adapt to warmer waters or find a way to move their range northward.
The study says white sturgeon and Pacific sardines were projected to increase in abundance under both climate change scenarios, while manila clams were projected to increase in abundance by 14.5 per cent in one of the models. The eight remaining species showed little change.
The study suggests that the southern territories (Tsawwassen, Tla’amin, and Maa-nulth First Nations) will likely see a reduction in catch potential between -15.2 per cent and -27.8 per cent depending on how the climate changes.
On the north coast. The Haida and Tsimshian First Nations and those situated along the central or north-eastern coasts of Vancouver Island (Heiltsuk and ‘Namgis First Nations) would likely see smaller reductions in relative catch for each territory, with estimates falling between -3.2 per cent and -8.2 per cent.
The study shows that for the First Nations along the North and Central Coasts of British Columbia (Gitga’at and Haida, and Heiltsuk and ‘Namgis) there will be neutral or positive shifts in catch potential for white sturgeon, kelp greenling, and two species of perch under both scenarios.
While varying regionally, both scenarios also suggested either a slight cumulative decline or negligible change in catch potential for clams, rockfish, lingcod, and sculpins across the North and Central Coast.
One potential problem the study suggests is that fishers in southern British Columbia may, in the future, try to move north to follow the harvest, leading to potential conflicts. The cost of travel, may, however, discourage that.
One of the recommendations from the study is that First Nations revive the traditional clam gardens.
Traditional clam beds serve as an ideal example of a method that could be applied to offset climatic impacts through internalized mechanisms, using local cultivation to generate increased productivity by enhancing native habitat rather than redirecting extraction efforts towards other regions or species. Clam gardens constructed in a manner akin to those situated near ancient settlements of the Northern Coast Salish and Laich-kwil-tach First Nations have been found to generate higher clam densities, biomass, and growth rates than non-walled beaches . These benefits were observed for Pacific littleneck clams and butter clams , two clams that are of cultural, economic, and ecological importance to the region Reinstating clam beds in First Nations’ territorial lands has been suggested as a means of simultaneously achieving local conservation and cultural objectives and may thereby provide a politically and ecologically viable option for mitigating climate-related impacts.
The most important recommendation is that the First Nations and other stakeholders start cooperating immediately to offset how the changing climate with affect the fishery:
Management of salmon and herring stocks has been highly contentious due to the myriad of stakeholders who depend upon them, which include First Nations, recreational fisheries, and commercial fisheries….
Aside from fulfilling societal needs, salmon serve as key ecological components of the Pacific Northwest Coast, functioning as the mechanisms by which nutrients are transferred from the ocean to freshwater and terrestrial ecosystems
It says the projections show that a “redistribution of fishing effort” will not “fully offset declines in salmon and herring”
attaining a state of collaboration between First Nations, DFO, and other sectors has the potential to yield beneficial ecological and political results, if implemented correctly. Parallels exist between First Nations’ traditional fisheries management approaches and “modern” approaches (e.g., spatial management, mariculture, selective fishing, fishing closures), with differences arising primarily due to diverging worldviews.
It recommends local application of First Nations’ traditional management strategies to “provide opportunities to collaboratively engage in adaptive ecosystem-based management and to coordinate efforts to attain conservation objectives.”
They give an example of how the Nisga’a Nation have ensured their equal partnership in management by employing traditional fish wheel technology to monitor and assess stocks and by leveraging traditional ecosystem-based management practices that could be applied to plan long-term objectives and management approaches.
It concludes by saying that joint-management will not only work to reduce the impact of climate change but also head off potential conflict.
Through such joint-management regimes, traditional fisheries management strategies could be applied to advance localized research directives and to reduce impacts on stocks under unprecedented environmental change. Moreover, the risk of conflict over declining resources underlines the need to establish common and equitable ground to ensure successful joint management of fisheries, and to leverage collective expertise.
A “devastating megathrust earthquake” could hit Haida Gwaii sometime in the future, according to Canadian and US studies carried out after the magnitude 7.8 earthquake off Haida Gwaii on Oct. 27, 2012 and the 7.5 magnitude quake off Craig, Alaska, a few weeks later on Jan. 5, 2013.
The 2004 Indian Ocean earthquake and the 2011 Tōhoku earthquake in Japan, both accompanied by major tsunamis are recent examples of “great” (higher than magnitude 8.0) megathrust earthquakes. Most of the concern on the west coast has been the likelihood of a megathrust earthquake on the Cascadia Fault on the Juan de Fuca plate that stretches from northern California to the middle of Vancouver Island.
The 2012 Haida Gwaii main shock was the second largest seismic event in Canada since the establishment of a modern seismograph network. The first was the 1949 Haida Gwaii/Queen Charlotte earthquake with a magnitude of 8.1 That 1949 Haida Gwaii earthquake was a strike-slip event, where the plates move side-to-side, similar to the 1906 San Francisco earthquake and other quakes on the San Andreas Fault in California.
The 2012 Haida Gwaii earthquake is characterized in the studies as a “mini-megathrust” event, where part of the crust is pushed upward, meaning that a larger megathrust could have much more destructive consequences from both the earthquake and a possible tsunami.
Complex system of faults
The new studies show that the Pacific and North America plate boundary off the coast of British Columbia and southeastern Alaska creates a system of faults capable of producing very large earthquakes. The scientists conclude that while the two earthquakes in 2012 and 2013 released strain built up over years on the tectonic plates, those events did not release strain along the Queen Charlotte Fault off the west coast of Haida Gwaii. That means the fault remains the likely source of a future large earthquake.
A special issue of the Bulletin of the Seismological Society of America (BSSA), released Monday, April 6, 2015, contains 19 scientific and technical papers, outlining the results of the work carried out over the past two years.
The team estimated the rupture dimension of the 2012 Haida Gwaii earthquake to be about 120 kilometres long at a depth of about 30 kilometres.
The Craig earthquake ruptured the Queen Charlotte fault over a distance of more than 100 kilometres and at a depth of about 20 kilometres.
The two areas are joined in what is called the Queen Charlotte Fairweather Fault System. To the south the Queen Charlotte Fault also interacts with the Juan de Fuca plate that stretches from Vancouver Island to northern California.
“The study of these two quakes revealed rich details about the interaction between the Pacific and North America Plates, advancing our understanding of the seismic hazard for the region,” said Thomas James, research scientist at Geological Survey of Canada.
Two faults off Haida Gwaii
The studies conclude that the interaction between the plates off Haida Gwaii is much more complex than previously believed. Before the 2012 earthquake, the Queen Charlotte Fault, a strike-slip fault similar to the San Andreas Fault in California, was believed to be the dominating tectonic structure in the area. The 2012 tremor confirmed the existence of a previously suspected thrust fault beneath what is called the “Queen Charlotte Terrace,” to the west of the Queen Charlotte Fault, where the Pacific plate is sliding at a low angle below the North American plate.
The Queen Charlotte Terrace, which is about a kilometre below the surface of the ocean, is built up of layers of sediment, several kilometres thick, scraped off the oceanic plate as it subducts under the North American plate. It may also include some fragments of oceanic crust. For most of the terrace, it is “present as a clearly defined linear feature,” but the study adds: “north of about 53.5° N, a complex pattern of ridges and valleys appears.”
The earthquake was “essentially a mini-megathrust earthquake along the dipping plate interface of a subduction system,” one of the scientific papers says. The epicenter of the Haida Gwaii main shock was located about five kilometres landward (northeast) of the Queen Charlotte Fault. That probably means that the rupture was near the bottom of the locked plates, where the plate motion’s side to side movement is also thrusting downward. Significant aftershocks appeared to cluster on the periphery of the main rupture zone with most of the aftershocks occurring seaward to the west.
The scientists used GPS observations of crustal motion to locate the earthquake’s rupture offshore to the west of Haida Gwaii.
The situation off Haida Gwaii is complex because while the Pacific plate is converging with the North American plate at a rate of 15 to 20 millimetres a year, at the same time the two plates are slipping by each other toward the north northwest at angle of about 20 degrees at a rate of about 50 millimetres a year.
Honn Kao, a seismologist with the Geological Survey of Canada said, “This was an event the thrust interface of the plate boundary system, confirming that there is a subduction system in the Haida Gwaii area.
“The implication of a confirmed subduction zone is that in addition to the Queen Charlotte Fault, we now have another source which can produce devastating megathrust earthquakes in the area,” said Kao.
The study of the Haida Gwaii tremor looked at the causative faults, the rupture processes and depths of the main shock and sequence of strong aftershocks.
The Haida Gwaii earthquake generated a significant tsunami that left deposits indicating run-up exceeding 3 metres (maximum 13 metres) in a number of bays and inlets along about 230 kilometres along the west coast of Haida Gwaii. In Hawaii, a 0.8 metre wave was measured on a tide gauge.
In Queen Charlotte City perceptible shaking lasted for one and half to two minutes, with very strong shaking for about 30 seconds. The earthquake was felt as far away as Yukon Territory, Alberta, and Montana.
The study says “Damage was limited, in part owing to the sparse population, but also because of the seismic resistance of the generally low rise, wood-frame buildings on the islands. Felt intensities were at expected values close to the source zone, but regional intensities were smaller than predicted.”
The Haida Gwaii rupture also shook southeastern Alaska. The northwest direction of ground motion then may have influenced the timing of the Craig earthquake a few weeks later in January 2013. That earthquake occurred farther north in southeast Alaska, where relative plate motion is nearly parallel to the Queen Charlotte fault.
The Haida Gwaii aftershocks clustered around the periphery of the rupture zone, both on the seaward and landward side of the plate boundary and reflected what the study calls “normal faulting behavior–caused by the bending, extending or stretching of rock– rather than the thrust faulting of the main shock.” The pattern of aftershocks is similar to those observed after the 2011 Japanese megathrust earthquake.
“Our observations of normal faulting imply that the main shock of the Haida Gwaii earthquake dramatically altered the stress field in the rupture zone, especially in a neighboring region,” Kao said.
The distribution of aftershocks occurred to the north of a previously identified seismic gap where large earthquakes have not occurred in historic times. The gap is located to the south of the where 1949 magnitude 8.1 Queen Charlotte earthquake ruptured.
Though the Haida Gwaii earthquake may have activated some part of the Queen Charlotte Fault, Kao said, it was limited and did not relieve stress along the seismic gap.
The study concludes:
The Haida Gwaii event confirmed substantial seismic and tsunami hazard from large thrust events on the plate margin along the southern Queen Charlotte fault. It occurred where relatively young oceanic lithosphere under thrusts North America and in some ways is an analog for the much larger megathrust earthquakes known to occur on the Cascadia subduction zone to the south, where the young Juan de Fuca plate and other small plates subduct beneath North America. The Haida Gwaii earthquake had a complex pattern of main shock rupture and aftershocks and a large tsunami.
Further study needed
The Geological Survey of Canada plans further studies to understand the formations off Haida Gwaii.
One question to ask is if there are any records of major earthquake events in the past history of Haida Gwaii. The study notes that the impact of the tsunami was relatively minor “in this region with steep rocky coastlines.” That means there are limited sources of coastal sediments that can be checked for past events. It adds: “Low-elevation lakes, ponds, and bogs may offer the best opportunities for paleotsunami studies” warning that large earthquakes in the past that produced tsunamis may have left little evidence in the “paleoseismic record of Haida Gwaii and similar settings worldwide.”
Megathrust earthquakes occur at subduction zones at destructive plate boundaries where one tectonic plate is subducted (forced underneath) by another. These interplate earthquakes are the planet’s most powerful, with moment magnitudes that can exceed 9.0. Since 1900, all earthquakes of magnitude 9.0 or greater have been megathrust earthquakes. During the rupture, one side of the fault is pushed upwards relative to the other, and it is this type of movement that is known as thrust. The displacement of the ocean in a thrust can trigger a tsunami.
A transform fault is one where the motion is predominantly horizontal. Those faults end abruptly and are connected on both ends to other faults, ridges, or subduction zones. The best-known (and most destructive) are those on land at the margins of tectonic plates. Transform faults are the only type of strike-slip faults at plate boundaries show strike-slip or side-to-side in movement.
Queen Charlotte Terrace
The Queen Charlotte Terrace is a 25 kilometre wide zone of built up marine sediment immediately west of the active Queen Charlotte fault. The crust is about 12 kilometres thick at the terrace. On Haida Gwaii, the earth’s crust is 18 kilometres thick at the eastern edge. On the BC mainland the crust is in excess of 30 kilometres thick.
The 1949 Haida Gwaii quake was one of the largest in the recorded history of North America.
The largest known earthquake along the coast was the megathrust event on the Cascadia fault on January 26, 1700 where the Juan de Fuca plate ruptured for about 1,000 kilometres along from what is now northern California to Vancouver Island, estimated at magnitude 9.0. The dating is based on a tsunami that hit Japan that had no associated local earthquake as well studies of tree rings from the remains of trees downed in the tsunami.
Three studies of the geology of Douglas Channel are near completion and publication, according to Natural Resources Canada. That news comes as studies, released today, warn of a major megathrust earthquake on the fault west of Haida Gwaii.
Northwest Coast Energy News asked the Geological Survey of Canada if there were any recent updates available after the agency said that a survey had located a “possible fault” on Hawkesbury Island during studies for the Enbridge Northern Gateway Joint Review Panel.
Natural Resources Canada responded with a statement: “NRCan continues to conduct research studies in the area, including study of possible faults. Three scientific expeditions have been completed on board Coast Guard research ships. The first two reports are in the final stages of editing, and will be published in the coming months. The third expedition was just completed; therefore the third report will be available later.”
More recently there were slope failures nearer to Kitimat. The first slope failure occurred on October 17, 1974, triggering a 2.4 metre tsunami at low tide. Then on April 27, 1975 there was a second slope failure near low tide on the northeast slope of the Kitimat Arm that generated an 8.2 metre tsunami. The 1975 tsunami destroyed the Northland Navigation dock near Kitimat and damaged the Haisla First Nation docks at Kitamaat Village.
Thomas James, of the Geological Survey told Northwest Coast Energy news about the team’s finding on the Haida Gwaii earthquake: “The studies focused on the Haida Gwaii and Craig earthquakes which happened at the Pacific and North American plate boundary, west of Haida Gwaii, so east of Haida Gwaii there’s no comparable plate boundaries that gives rise of historic sieismisticity.”
As well as the fact that recent studies say the mainland margin coastal zone has had very little historical seismicity, it adds no currently active faults have been identified. A study ten years ago identified some very ancient faults which have not been active since the Eocene, about 33 to 56 million years ago.
GPS studies show that in northwestern British Columbia coastal block is moving northeast at the rate of just 5 millimetres a year.
Climate change, which will raise ocean temperatures and more carbon dioxide in the atmosphere which will increase the acidification of the oceans will have the greatest affect on the intertidal zones—and a key indicator species, crabs and similar creatures.
A study by San Fransisco State University published today in the Journal of Experimental Biology used the small (usually 15 millimetre) porcelain crab to simulate the conditions that will come to the intertidal zone and affect other species including the larger dungeness crab. ( According to Wikipedia, porcelain crabs are an example of carcinisation, whereby a non-crab-like animal,in this case a relative of a squat lobster evolves into an animal that resembles a true crab.)
Studies have shown that as climate changes, coastal ecosystems will be see “have increased extremes of low tide-associated thermal stress and ocean acidification-associated low pH.”
The study by co-author Jonathan Stillman and his colleagues, is the first to explore intertidal zone organisms’ response to combined variation in temperature and pH, which is expected to intensify in the future due to climate change and ocean acidification.
The current and previous studies have shown that during low tide, air temperatures in the intertidal zone can fluctuate dramatically as much as 20 degrees celcius over short periods of time up to six hours. Temperatures can reach extremes when low tides coincide with hot days. Marine intertidal organisms tolerate these natural temperature fluctuations, yet it is known that they are limited in their scope to tolerate future warming.
In the simulation porcelain crabs were placed in a specially built aquarium designed to simulate the natural environment, including tidal changes. At low tide, with the crabs exposed to the air, the researchers varied the temperature to mirror day-to-day changes the crabs currently experience — such as cooler air on a cloudy day and warmer air on a sunny day — as well as conditions expected in the future. At high tide, with the crabs submerged, they adjusted pH levels in the same fashion.
As the temperature rose and pH levels dropped — conditions expected in the future due to climate change — the crabs’ ability to withstand heat increased. But at the same time, researchers found, the crabs’ metabolism decreased. In addition, the combined effect of higher temperatures and lower pH levels was greater than the effect of either of those two factors alone.
“When you combine these things together, they slow down metabolism, which means crabs become sluggish and have less overall energy to do things like growth or reproduction,” Stillman said. “If their whole energy budget is a pie, then in the future the size of the pie is going to be smaller, and a larger percentage of it is going to be taken up by survival and maintenance.”
The study says that although porcelain crabs are not particularly important to humans — they are not fishery crabs such as Dungeness — they are an important food source for coastal fish, birds and other crabs.
The results suggest “there is a potential for adverse long-term ecological consequences for intertidal ectotherms”– that is creatures that depend on the external temperatures to regulate body heat– “exposed to increased extremes in pH and temperature due to reduced energy for behavior and reproduction.”
The porcelain crabs can also be seen as a model for scientists to understand the impacts of climate change and ocean acidification on crustaceans in general, Stillman said. Future studies will look at the impact of varying temperature and pH changes on different species of porcelain crabs, juvenile crabs and crab embryos.
The United States says acidification of the oceans means there is an already growing risk to the northwest coast fishery, including crab and salmon, according to studies released by the National Oceanic and Atmospheric Administration.
As more carbon dioxide is released into the atmosphere and absorbed by the oceans, the water is becoming more acidic and that affects many species, especially shellfish, dissolving the shells.
A NOAA study released today of environmental and economic risks to the Alaska fishery says:
Many of Alaska’s nutritionally and economically valuable marine fisheries are located in waters that are already experiencing ocean acidification, and will see more in the near future…. Communities in southeast and southwest Alaska face the highest risk from ocean acidification because they rely heavily on fisheries that are expected to be most affected by ocean acidification…
An earlier NOAA study, released in April, identified a long term threat to the salmon fishery as small ocean snails called pteropods which are a prime food source for pink salmon are already being affected by the acidification of the ocean.
The term “ocean acidification” describes the process of ocean water becoming more acidic as a result of absorbing nearly a third of the carbon dioxide released into the atmosphere from human sources. This change in ocean chemistry is affecting marine life, particularly the ability of shellfish, corals and small creatures in the early stages of the food chain to build skeletons or shells.
Today’s NOAA study is the first published research by the Synthesis of Arctic Research (SOAR) program, which is supported by an US inter-agency agreement between NOAA’s Office of Oceanic and Atmospheric Research and the Bureau of Ocean Energy Management (BOEM) Alaska Region.
Des Nobles, President of Local #37 Fish [UFAWU-UNIFOR] told Northwest Coast Energy News that the fisheries union and other fisheries groups in Prince Rupert have asked both the Canadian federal and the BC provincial governments for action on ocean acidification. Nobles says so far those requests have been ignored,
Threat to crabs
The studies show that red king crab and tanner crab grow more slowly and don’t survive as well in more acidic waters. Alaska’s coastal waters are particularly vulnerable to ocean acidification because of cold water that can absorb more carbon dioxide and unique ocean circulation patterns which bring naturally acidic deep ocean waters to the surface.
“We went beyond the traditional approach of looking at dollars lost or species impacted; we know these fisheries are lifelines for native communities and what we’ve learned will help them adapt to a changing ocean environment,” said Jeremy Mathis, Ph.D., co-lead author of the study, an oceanographer at NOAA’s Pacific Marine Environmental Laboratory in Seattle, and the director of the University of Alaska Fairbanks School of Fisheries and Ocean Sciences Ocean Acidification Research Center.
As for Dungeness crab, Sarah Cooley, a co-author of the Alaska study, who was with the Woods Hole Oceanographic Institution at the time, told Northwest Coast Energy News, “The studies have not been done for Dungeness crab that have been done for king and tanner crab, that’s something we’re keenly aware of. There’s a big knowledge gap at this point.” She says NOAA may soon be looking at pilot study on Dungeness crab.
Risk to Salmon, Mackerel and Herring
In a 2011-2013 survey, a NOAA-led research team found the first evidence: “that acidity of continental shelf waters off the West Coast is dissolving the shells of tiny free-swimming marine snails, called pteropods, which provide food for pink salmon, mackerel and herring.”
The survey estimated that the percentage of pteropods along the west coast with dissolving shells due to ocean acidification had “doubled in the near shore habitat since the pre-industrial era and is on track to triple by 2050 when coastal waters become 70 percent more corrosive than in the pre-industrial era due to human-caused ocean acidification.”
That study documented the movement of corrosive waters onto the continental shelf from April to September during the upwelling season, when winds bring water rich in carbon dioxide up from depths of about 120 to 180 metres to the surface and onto the continental shelf.
“We haven’t done the extensive amount of studies yet on the young salmon fry,” Cooley said. “I would love to see those studies done. I think there is a real need for that information. Salmon are just so so important for the entire Pacific Northwest and up to Alaska.”
In Prince Rupert, Barb Faggetter, an independent oceanographer whose company Ocean Ecology has consulted for the fisherman’s union and NGOs, who was not part of the study, spoke generally about the threat of acidification to the region.
She is currently studying the impact of the proposed Liquified Natural Gas terminals that could be built at Prince Rupert near the Skeena River estuary. Faggetter said that acidification could affect the species eaten by juvenile salmon. “As young juveniles they eat a lot of zooplankton including crustaceans and shell fish larvae.”
She added, “Any of the shell fish in the fishery, including probably things like sea urchins are all organisms that are susceptible to ocean acidification because of the loss of their capacity to actually incorporate calcium carbonate into their shells.”
Faggetter said her studies have concentrated on potential habitat loss near Prince Rupert as a result of dredging and other activities for liquified natural gas development, She adds that ocean acidification “has been a consideration that climate change will further worsen any potential damage that we’re currently looking at.”
Her studies of the Skeena estuary are concentrating on “rating” areas based on the food supply available to juvenile salmon, as well as predation and what habitat is available and the quality of that habitat to identify areas that “are most important for the juvenile salmon coming out of the Skeena River estuary and which are less important.”
She said that climate change and ocean acidification could impact the Skeena estuary and “probably reduce some of the environments that are currently good because they have a good food supply. If ocean acidification reduces that food supply that will no longer be good habitat for them” [juvenile salmon].
The August 2011 NOAA survey of the pteropods was done at sea using “bongo nets” to retrieve the small snails at depths up to 200 metres. The research drew upon a West Coast survey by the NOAA Ocean Acidification Program in that was conducted on board the R/V Wecoma, owned by the National Science Foundation and operated by Oregon State University.
Nina Bednarsek, Ph.D., of NOAA’s Pacific Marine Environmental Laboratory in Seattle, the lead author of the April pteropod paper said, “Our findings are the first evidence that a large fraction of the West Coast pteropod population is being affected by ocean acidification.
“Dissolving coastal pteropod shells point to the need to study how acidification may be affecting the larger marine ecosystem. These near shore waters provide essential habitat to a great diversity of marine species, including many economically important fish that support coastal economies and provide us with food.”
Ecology and economy
Today’s study on the effects of acidification on the Alaska fishery study examined the potential effects on a state where the fishing industry supports over 100,000 jobs and generates more than $5 billion in annual revenue. Fishery-related tourism also brings in $300 million annually to the state.
The study also shows that approximately 120,000 people or roughly 17 percent of Alaskans rely on subsistence fisheries for most, if not all of their dietary protein. The Alaska subsistence fishery is open to all residents of the state who need it, although a majority of those who participate in the subsistence fishery are Alaska’s First Nations. In that way it is somewhat parallel to Canada’s Food, Ceremonial and Social program for First Nations.
“Ocean acidification is not just an ecological problem—it’s an economic problem,” said Steve Colt, Ph.D., co-author of the study and an economist at the University of Alaska Anchorage. “The people of coastal Alaska, who have always looked to the sea for sustenance and prosperity, will be most affected. But all Alaskans need to understand how and where ocean acidification threatens our marine resources so that we can work together to address the challenges and maintain healthy and productive coastal communities.”
The Alaska study recommends that residents and stakeholders in vulnerable regions prepare for environmental challenge and develop response strategies that incorporate community values and needs.
“This research allows planners to think creatively about ways to help coastal communities withstand environmental change,” said Cooley, who is now science outreach manager at Ocean Conservancy, in Washington, D.C. “Adaptations can be tailored to address specific social and environmental weak points that exist in a community.
“This is really the first time that we’ve been able to go under the hood and really look at the factors that make a particular community in a borough or census are less or more vulnerable from changing conditions resulting from acidification. It gives us a lot of power so that we don’t just look at environmental issues but also look at the social story behind that risk.”
As for the southern part of the Alaska panhandle nearest British Columbia, Cooley said, “What we found is that there is a high relative risk compared to some of the other areas of Alaska and that is because the communities there undertake a lot of subsistence fishing, There tend not be a whole lot of commercial harvests in the fisheries there but they are very very important from a subsistence stand point… And they’re tied to species that we expect to be on the front line of acidification, many of the clam species that are harvested in that area and some of the crab species.”
Long term effects
Libby Jewett, Director of the NOAA Ocean Acidification Program and author of the pteropod study said, “Acidification of our oceans may impact marine ecosystems in a way that threatens the sustainability of the marine resources we depend on.
“Research on the progression and impacts of ocean acidification is vital to understanding the consequences of our burning of fossil fuels.”
“Acidification is happening now,” Cooley said. “We have not yet observed major declines in Alaskan harvested species. In Washington and Oregon they have seen widespread oyster mortality from acidification.
“We don’t have the documentation for what’s happening in Alaska right now but there are a lot of studies staring up right now that will just keep an eye out for that sort of thing, Acidification is going to be continuing progressively over the next decades into the future indefinitely until we really curb carbon dioxide emissions. There’s enough momentum in the system that is going to keep acidification advancing for quite some time.
“What we need to be doing as we cut the carbon dioxide, we need to find ways to strength communities that depend on resources and this study allows us to think differently about that and too really look at how we can strengthen those communities.
Faggetter said. “It’s one more blow to an already complex situation here, My study has been working particularly on eel grass on Flora Bank (pdf) which is a very critical habitat, which is going to be impacted by these potential industrial developments and that impact will affect our juvenile salmon and our salmon fishery very dramatically, that could be further worsened by ocean acidification.”
She said that acidification could also be a long term threat to plans in Prince Rupert to establish a geoduck fishery (pronounced gooey-duck).
The popular large 15 to 20 centimetre clam is harvested in Washington State and southern BC, but so far hasn’t been subject to commercial fishing in the north.
NOAA said today’s study shows that by examining all the factors that contribute to risk, more opportunities can be found to prevent harm to human communities at a local level. Decision-makers can address socioeconomic factors that lower the ability of people and communities to adapt to environmental change, such as low incomes, poor nutrition, lack of educational attainment and lack of diverse employment opportunities.
NOAA’s Ocean Acidification Program and the state of Alaska are also developing tools to help industry adapt to increasing acidity.
The new NOAA study is the first published research by the Synthesis of Arctic Research (SOAR) program. which is supported by an inter-agency agreement between NOAA’s Office of Oceanic and Atmospheric Research and the Bureau of Ocean Energy Management (BOEM) Alaska Region.
MAPP stands for Marine Planning Partnership for the North Pacific Ocean.
According to the documents the purpose of the North Coast Marine Plan “is to provide recommendations for achieving a sustainable balance between ecosystem health, social and cultural well-‐being and economic development through an ecosystem-‐based approach to planning and management.”
The plan is all about managing “common First Nation and provincial interests related to marine areas.”
The parners include the province and the Skeena First Nations Stewardship Society (NCSFNSS), representing the Metlakatla, Kitsumkalum, Kitselas, Haisla, Gitga’at, and Gitxaala Nations.
According to the doucments the North Coast plan area covers 27,000 kilometres of coastline;
that is indented with deep fjords and dotted with thousands of islands. It is a region of profound beauty, significant ecological diversity and remarkable cultural richness. Prince Rupert, Terrace and Kitimat are the largest communities in the North Coast plan area, which supports an overall population of approximately 42,000.
According to the summary of the plan:
The physical complexity of the North Coast includes a range of ecosystem types, including important estuaries that support distinct marine ecosystems and species. A diverse range of economic and community activities occur within the North Coast plan area. Commercial fisheries and associated processing facilities and logging have supported communities along the coast since the early 1900s. These activities continue to be important to the well-‐being of coastal communities. Port activities centered around the communities of Prince Rupert, Kitimat and Stewart, and active recreational fishing and tourism sectors, continue to be strong economic drivers in the area. North Coast First Nations living in the region have distinct cultural and spiritual heritages that are intricately linked to the marine environment and the long-‐standing sustainable use and management of marine resources.
The plan appears to overlap some areas where there have been environmental assessments of the Northern Gateway and the numerous liquified natural gas proposals.
The plan summary goes on to say:
The draft plan brings together science and Aboriginal knowledge, input from the technical staff of NCSFNSS (representing the Gitga’at, Gitxaała, Metlakatla, Kitsumkalum, Kitselas and Haisla Nations) and the Province. Key information and direction was provided by First Nations strategic marine use plans and existing provincial planning and policy documents.
Ecological, cultural and social and economic data sources were compiled and analysed by the joint technical team and contract support. Relevant background scientific reports and technical documents from the Pacific North Coast Integrated Management Area (PNCIMA) process were also used, along with the BC Marine Conservation Analysis. Additional information was drawn from government reports and publications, academic literature, industry or sector publications, discussions with experts and local knowledge. Advice was also incorporated from the North Coast Marine Plan Advisory Committee and public and stakeholder engagement.
That was 25 years ago. The media loves anniversary stories and the Exxon Valdez look-backs and updates are already ramping up—right in the middle of the Kitimat plebiscite on the Northern Gateway pipeline and terminal project.
The hashtag #ExxonValdez25 is beginning to trend, based on a Twitter chat for Monday sponsored by the US National Oceanic and Atmospheric Administration.
The voters of Kitimat who will have to cast their ballots on the Joint Review Panel’s interpretation of the Northern Gateway proposal will find once again that the JRP tilted toward the industry and downplayed the lingering risks from a major tanker disaster—and that means neither the pro nor the anti side can be happy with the events that will be marked on March 24, 2014.
The Exxon Valdez accident is part of the Joint Review Panel findings that the economic benefits of Northern Gateway outweigh the risks. The JRP generally accepted the industry position, taken by both Northern Gateway and by ExxonMobil that Prince William Sound has recovered from the Exxon Valdez incident, something that is fiercely debated and disputed.
One area that is not in dispute is that the Exxon Valez disaster brought laws that forced energy companies to use double-hulled tankers. However, commercials that indicate that Northern Gateway will be using double-hulled tankers because the company respects the BC coast is pushing things a bit far, since those tankers are required by law.
Northern Gateway told the Joint Reivew Panel that
on a worldwide basis, all data sets show a steady reduction in the number
and size of oil spills since the 1970s. This decline has been even more apparent since regulatory changes in 1990 following the Exxon Valdez oil spill, which required a phase-in of double-hulled tankers in the international fleet. No double-hulled tanker has sunk since 1990. There have been five incidents of double-hulled tankers that have had a collision or grounding that penetrated the cargo tanks. Resulting spills ranged from 700 to 2500 tonnes
The Haisla countered by saying:
The Haisla Nation said that, although there have been no major spills since the Exxon Valdez spill in Prince William Sound, there were 111 reported incidents involving tanker traffic in Prince William Sound between 1997 and 2007. The three most common types of incidents were equipment malfunctions, problems with propulsion, steering, or engine function, and very small spills from tankers at berth at the marine terminal. The Haisla Nation said that, in the absence of state-of-the-art prevention systems in Prince William Sound, any one of those incidents could have resulted in major vessel casualties or oil spills.
The herring of Prince William Sound still have not recovered. Neither have killer whales, and legal issues remain unresolved a quarter of a century later. Monday is the 25th anniversary of the disaster, in which the tanker Exxon Valdez ran aground on Bligh Reef and spilled at least 11 million gallons of oil into the pristine waters of the sound.
Prince William Sound today looks spectacular, a stunning landscape of mountainous fjords, blue-green waters and thickly forested islands. Pick up a stone on a rocky beach, maybe dig a little, though, and it is possible to still find pockets of oil.
“I think the big surprise for all of us who have worked on this thing for the last 25 years has been the continued presence of relatively fresh oil,” said Gary Shigenaka, a marine biologist for the National Oceanic and Atmospheric Administration.
The legal dispute over the spill is still ongoing, with the Telegraph’s Joanna Walters noting:
[S]tate senator Berta Gardner is pushing for Alaskan politicians to demand that the US government forces ExxonMobil Corporation to pay up a final $92 million (£57 million), in what has become the longest-running environmental court case in history. The money would primarily be spent on addressing the crippled herring numbers and the oiled beaches.
“There’s still damage from the spill. The oil on the beaches is toxic and hurting wildlife. We can’t just say we’ve done what we can and it’s all over – especially with drilling anticipated offshore in the Arctic Ocean – this is significant for Alaska and people around the world,” she told The Telegraph.
An ExxonMobil spokesman then told The Telegraph, the energy sector’s standard response:
Richard Keil, a senior media relations adviser at ExxonMobil, said: “The overwhelming consensus of peer-reviewed scientific papers is that Prince William Sound has recovered and the ecosystem is healthy and thriving.”
But federal scientists estimate that between 16,000 and 21,000 gallons of oil from the spill lingers on beaches in Prince William Sound and up to 450 miles away, some of it no more biodegraded than it was at the time of the disaster.
Overall, the Exxon Valdez disaster was, as US National Public Radio reported, a spur to science. But NPR’s conclusion is the exact opposite of that from the Northern Gateway Joint Review Panel—at least when it comes to fish embryos.
Twenty-five years of research following the Exxon Valdez disaster has led to some startling conclusions about the persistent effects of spilled oil.
When the tanker leaked millions of gallons of the Alaskan coast, scientists predicted major environmental damage, but they expected those effects to be short lived. Instead, they’ve stretched out for many years.
What researchers learned as they puzzled through the reasons for the delayed recovery fundamentally changed the way scientists view oil spills. One of their most surprising discoveries was that long-lasting components of oil thought to be benign turned out to cause chronic damage to fish hearts when fish were exposed to tiny concentrations of the compounds as embryos.
It seems that some species recovered better than others from the oilspill.
For example, the recovery of the sea otter population has received widespread media coverage, but with widely divergent points of view. The more conservative and pro-industry writers point to the recovery of the otter population, while environmental coverage stresses the quarter century it took for the otter population to rebound.
Although recovery timelines varied widely among species, our work shows that recovery of species vulnerable to long-term effects of oil spills can take decades,” said lead author of the study, Brenda Ballachey, research biologist with the U.S. Geological Survey. “For sea otters, we began to see signs of recovery in the years leading up to 2009, two decades after the spill, and the most recent results from 2011 to 2013 are consistent with recovery
The Joint Review Panel generally accepted Northern Gateway’s and the energy industry’s evidence on the Exxon Valdez incident and concluded
The Panel’s finding regarding ecosystem recovery following a large spill is based on extensive scientific evidence filed by many parties, including information on recovery of the environment from large past spill events such as the Exxon Valdez oil spill. The Panel notes that different parties sometimes referred to the same studies on environmental recovery after oil spills, and drew different conclusions.
In its consideration of natural recovery of the environment, the Panel focused on effects that are more readily measurable such as population level impacts, harvest levels, or established environmental quality criteria such as water and sediment quality criteria.
The Panel finds that the evidence indicates that ecosystems will recover over time after a spill and that the post-spill ecosystem will share functional attributes of the pre-spill one. Postspill ecosystems may not be identical to pre-spill ecosystems. Certain ecosystem components may continue to show effects, and residual oil may remain in some locations. In certain unlikely circumstances, the Panel finds that a localized population or species could potentially be permanently affected by an oil spill.
Scientific studies after the Exxon Valdez spill indicated that the vast majority of species recovered following the spill and that functioning ecosystems, similar to those existing pre-spill, were established.
Species for which recovery is not fully apparent, such as Pacific herring, killer whales, and pigeon guillemots, appear to have been affected by other environmental factors or human influences not associated with the oil spill. Insufficient pre-spill baseline data on these species contributed to difficulties in determining the extent of spill effects.
Based on the evidence, the Panel finds that natural recovery of the aquatic environment after an oil spill is likely to be the primary recovery mechanism, particularly for marine spills. Both freshwater and marine ecosystem recovery is further mitigated where cleanup is possible, effective, and beneficial to the environment.
Natural processes that degrade oil would begin immediately following a spill. Although residual oil could remain buried in sediments for years, the Panel finds that toxicity associated with that oil would decline over time and would not cause widespread, long-term impacts.
The Panel finds that Northern Gateway’s commitment to use human interventions, including available spill response technologies, would mitigate spill impacts to ecosystems and assist in species recovery..
It is clear, however, from the local coverage in Alaska and from the attention of the world’s media that Prince William Sound has not fully recovered from the Exxon Valdez incident (it may yet in who knows how many years). Anger and bitterness still remains among the residents of Alaska, especially since the court cases are dragging on after a quarter century.
Those are the kinds of issues that Kitimat residents will face when they vote in the plebiscite on April 12. Just who do the people of Kitimat believe, those who say the chances for a spill are remote and the environment and the economy will quickly recover? It probably depends on whether or not you consider 25 years quick. Twenty-five years is quick in geological time but it is a third or a half of a human life time.
As for the residents of Kitamaat Village, and probably many people in Kitimat, Haisla Chief Counsellor Ellis Ross summed it up in a Facebook posting on Sunday
If this happens in Kitamaat, all those campaigning for Enbridge will pack up and leave for another coastline to foul. Haisla don’t have much of a choice. We would have to stay and watch the court battles on who should pay what.
Ross is right. Whether it’s Prince William Sound or Douglas Channel, the people who live the region are stuck with the mess while the big companies walk away and the lawyers get rich.
Excerpts from the Northern Gateway Joint Review Panel report relating to the Exxon Valdez disaster.
Northern Gateway told the Joint Reivew Panel that
on a worldwide basis, all data sets show a steady reduction in the number
and size of oil spills since the 1970s. This decline has been even more apparent since regulatory changes in 1990 following the Exxon Valdez oil spill, which required a phase-in of double-hulled tankers in the international fleet. No double-hulled tanker has sunk since 1990. There have been five incidents of double-hulled tankers that have had a collision or grounding that penetrated the cargo tanks. Resulting spills ranged from 700 to 2500 tonnes
The Haisla countered by saying:
The Haisla Nation said that, although there have been no major spills since the Exxon Valdez spill in Prince William Sound, there were 111 reported incidents involving tanker traffic in Prince William Sound between 1997 and 2007. The three most common types of incidents were equipment malfunctions, problems with propulsion, steering, or engine function, and very small spills from tankers at berth at the marine terminal. The Haisla Nation said that, in the absence of state-of-the-art
prevention systems in Prince William Sound, any one of those incidents could have resulted in major vessel casualties or oil spills.
There were disputes about how the Exxon Valdez affected species in the Prince William Sound area:
Northern Gateway said that, although crabs are known to be sensitive to toxic effects, they have been shown to recover within 1 to 2 years following
a spill such as the Exxon Valdez incident. Northern Gateway said that Dungeness crab was a key indicator species in its assessment of spill effects.
Northern Gateway said that potential effects to razor clams are not as well studied. It said that sediment toxicity studies after the Exxon Valdez spill did not suggest significant effects on benthic invertebrates. Following the Exxon Valdez and
Selendang Ayu oil spills in Alaska, food safety closures for species such as mussels, urchins, and crabs were lifted within 1 to 2 years following the
In response to questioning from the Council of the Haida Nation regarding potential spill effects on herring, Northern Gateway said that herring were a key indicator species in its spill assessment.
Northern Gateway said that the Exxon Valdez spill did not appear to cause population-level effects on Prince William Sound herring.
As did throughout its report, the Joint Review Panel gave great weight to Northern Gateway’s evidence:
Northern Gateway said that potential effects of oil stranded on the shorelines and in the intertidal environment were assessed qualitatively with particular reference to the Exxon Valdez oil spill. It said that the entire intertidal zone along affected
shorelines would likely be oiled, coating rocks, rockweed, and sessile invertebrates. Some of the diluted bitumen could penetrate coarse-grained intertidal substrates, and could subsequently be remobilized by tides and waves. There were
relatively few shoreline areas with potential for long oil residency. Northern Gateway said that the stranded bitumen would not be uniformly distributed, and that heavy oiling would likely be limited to a small proportion of affected shoreline. Northern
Gateway said that, compared to the Exxon Valdez oil spill, the simulation suggested that more dilbit would be distributed along a shorter length of shoreline.
Northern Gateway said that, due to the relatively sheltered conditions in Wright Sound, and in the absence of cleanup, most of the stranded oil would be weathered or dispersed into the marine environment within 3 to 5 years. It said that,
while weathering and dispersal could represent an important secondary source of hydrocarbon contamination of offshore or subtidal sediments, the weathered hydrocarbons themselves would have lower toxicity than fresh dilbit.
Northern Gateway assessed potential effects on key marine receptors including marine water quality, subtidal sediment quality, intertidal sediment
quality, plankton, fish, and a number of bird and mammal species. The company said that acute effects from monocyclic aromatic hydrocarbons such as benzene, toluene, ethylbenzene, and xylene may briefly occur in some areas. Acute effects from polycyclic aromatic hydrocarbons were not likely due to their low water solubility.
Northern Gateway said that chronic adverse effects on the subtidal benthic community were not predicted. After a large spill, consumption advisories for pelagic, bottom-dwelling and anadromous fish, and invertebrates from open
water areas and subtidal sediments would probably be less than 1 year in duration. Northern Gateway said that consumption advisories for intertidal communities and associated invertebrates, such as mussels, could persist for 3 to 5 years or longer in
some sheltered areas.
But dilbit is different from heavy crude
In response to questions from the Haisla Nation and the United Fishermen and Allied
Workers Union, Fisheries and Oceans Canada said that, although it had a great deal of information on conventional oils, the results of research conducted on the biological effects of conventional oil products may not be true for dilbit or unconventional products. Fisheries and Oceans Canada said that it was not in a
position to quantify the magnitude and duration of impacts to marine resources
The United Fishermen and Allied Workers Union said that, because there are so many variables, each spill is a unique event, and some results will be unknowable. It said that a spill the size of the Exxon Valdez incident would affect the entire ecosystem
in the project area, and that recovery to pre-spill conditions would be unlikely to ever occur. It said that a spill the size of the Exxon Valdez oil spill would likely have similar effects in the project area because marine resources in the project area are
similar to those in Prince William Sound. It argued that the cold, sheltered, waters of the Confined Channel Assessment Area would likely experience reduced natural dispersion and biodegradation of oil, leading to heavier oiling and longer recovery
times than seen in Prince William Sound and elsewhere.
The United Fishermen and Allied Workers Union said that patches of buried oil from the Exxon Valdez oil have been found on sand and gravel beaches overlain by boulders and cobbles. It said that effects from a tanker spill associated with the
Enbridge Northern Gateway Project would likely be more severe than the Exxon Valdez oil spill due to the more persistent nature of dilbit and the lack of
natural cleaning action in the sheltered waters of the Confined Channel Assessment Area.
The Gitxaala Nation’s experts said that large historical spill events are not necessarily good indicators of what will happen in the future. They
argued that each spill has unique circumstances and there is still significant uncertainty about the effects of major spills.
The Gitxaala Nation concluded Northern Gateway had failed to adequately consider the potential consequences on ecological values of interest to the Gitxaala.
Gitga’at First Nation said that a spill of dilbit greater than 5,000 cubic metres would result in significant, adverse, long-term, lethal, and sublethal effects
to marine organisms, and that effects would be particularly long-lasting on intertidal species and habitats. It also said that effects from a tanker spill associated with the project would probably be more severe than the Exxon Valdez oil spill, due to
the more persistent nature of dilbit and the lack of natural cleaning action in the sheltered waters
The JRP told how Nothern Gateway looked at the scientific evidence:
The company used a case study approach and reviewed the scientific literature for environments similar to the project area. The review examined 48 spills, including the Exxon Valdez oil spill in 1989, and 155 valued ecosystem components from cold temperate and sub-arctic regions. Northern Gateway said that the scientific evidence is clear that, although oil spills have adverse effects on biophysical and human environments, ecosystems and their components recover with time.
Pacific herring, killer whales, and pink salmon were species that were extensively studied following the Exxon Valdez spill and were discussed by numerous participants in the Panel’s process.
As referred to by the Haisla Nation, Pacific herring are listed as “not recovering” by the Exxon Valdez Oil Spill Trustee Council. The Trustee Council said that, despite numerous studies to understand the effects of oil on herring, the causes constraining population recovery are not well understood.
Northern Gateway said that scientific evidence indicates that a combination of factors, including disease, nutrition, predation, and poor recruitment
appear to have contributed to the continued suppression of herring populations in Prince William Sound.
Northern Gateway said that 20 years of research on herring suggests that the Exxon Valdez oil spill is likely to have initially had localized effects on herring eggs and larvae, without causing effects at the population level. Northern Gateway said
that, even after 20 years, the effects of the spill on herring remain uncertain. It said that there has also been convergence amongst researchers that herring declines in the spill area cannot be connected to the spill.
Northern Gateway said that herring stocks along the entire coast of British
Columbia have been in overall decline for years and that herring were shown to recover within 1 to 2 years following the Nestucca barge spill.
A Gitxaala Nation expert noted the uncertainty in interpreting the decline of herring following the Exxon Valdez oil spill and said that the debate is not likely to ever be settled.
The Living Oceans Society said that the Exxon Valdez Oil Spill Trustee Council reported that some killer whale groups suffered long-term damage from initial exposure to the spill. Northern Gateway’s expert said the research leads him to
conclude that the actual effects on killer whales of the Exxon Valdez spill are unknowable due to numerous confounding factors. He said that the
Exxon Valdez Oil Spill Trustee Council has not definitively said that killer whale mortalities can be attributed to the spill. A Government of Canada
expert said that the weight of evidence suggests that the mortality of killer whales was most likely related to the spill.
Northern Gateway said that mass mortality of marine fish following a spill is rare. In response to questions from the Haisla Nation, Northern Gateway said that fish have the ability to metabolize potentially toxic substances such as polycyclic aromatic hydrocarbons. It said that international experience with oil spills has demonstrated that fin fishery closures tend to be very short in duration.
Northern Gateway said that food safety programs for fin fish conducted following the Exxon Valdez spill and the Selendang Ayu spill in Alaska indicated
that the finfish were not affected by the spill and that the fish were found, through food safety testing programs, to be safe to eat.
The Haisla Nation referred to the Exxon Valdez Oil Spill Trustee Council report that discussed the complexities and uncertainties in the recovery status of pink salmon. It said that, by 1999, pink salmon were listed as recovered and that the
report noted that continuing exposure of embryos to lingering oil is negligible and unlikely to limit populations.
Northern Gateway said that the longterm effect of the spill on pink salmon survival is
best demonstrated by the success of adult returns following the spill. Northern Gateway said that, in the month following the spill, when there was still
free oil throughout Prince William Sound, hundreds of millions of natural and hatchery pink salmon fry migrated through the area. It argued that these fish would arguably be at greatest risk from spill-related effects but that the adult returns 2 years later were one of the highest populations ever. Northern Gateway said that sockeye and pink salmon appear to have been unaffected by the Exxon Valdez spill
over the long term.
In response to questions from the Council of the Haida Nation and the United Fishermen and Allied Workers Union, Northern Gateway said that effects
on species such as seaweed, crabs, and clams have been shown to be relatively short-term, with these species typically recovering within 2 years or less
following a spill, depending on circumstances.
Northern Gateway said that, based on the Exxon Valdez spill, the level of hydrocarbons dissolved or suspended in the water column would be expected
to be substantially lower than those for which potential toxic effects on crabs or fish may occur.
In response to questions from BC Nature and Nature Canada, Northern Gateway said that the Exxon Valdez oil spill indicates which species of birds are most susceptible to oiling. Seabirds are generally vulnerable to oil spills because many species spend large amounts of time at sea. Diving seabirds such as murres are particularly vulnerable to oiling because they spend most of their time on the surface, where oil is found, and tend to raft together. Thus, these species often account for most of the bird mortality associated with oil spills.
More than 30,000 seabird carcasses, of which 74 per cent were murres, were recovered following the Exxon Valdez spill and it was initially estimated
that between 100,000 and 300,000 seabirds were killed. However, detailed surveys of breeding murres in 1991 indicated no overall difference from pre-spill levels confirming rapid recovery of this species.
Northern Gateway said that, although potential toxicological effects from oil spills on
birds have been well documented in laboratory studies, the ultimate measure of recovery potential is how quickly birds return to their natural abundance and reproductive performance. It said that recovery is often difficult to measure due to
significant natural variation in populations and the fact that the baseline is often disputed. It said that this can lead to misinterpretation of results depicting recovery.
At the request of Environment Canada, Northern Gateway filed two reports on the susceptibility of marine birds to oil and the acute and chronic effects of the Exxon Valdez oil spill on marine birds. Northern Gateway said that marine birds are
vulnerable to oil in several ways such as contact, direct or indirect ingestion, and loss of habitat.
It said that many marine bird populations appear to have recovered from the effects of the Exxon Valdez spill, but some species such as harlequin ducks and pigeon guillemots have not recovered, according to the Exxon Valdez Oil Spill Trustee
Council. It said these reports demonstrate that marine birds are susceptible to marine oil spills to varying degrees depending on the species, its life
history and habitat, and circumstances associated with the spill.
Northern Gateway concluded that:
• Marine, freshwater, and terrestrial environments recover from oil spills, with recovery time influenced by the environment, the valued ecosystem components of interest, and other factors such as spill volume and characteristics
of the oil. Depending on the species and circumstances, recovery can be quite rapid or it can range from 2 to 20 years. Other scientific reviews have indicated that recovery of marine environments from oil spills takes 2 to 10 years.
• Different marine ecosystem components recover at different rates. Recovery time can range from days or weeks in the case of water quality, to years or decades for sheltered, soft sediment marshes. Headlands and exposed rocky shores can take 1 to 4 years to recover.
• Little to no oil remained on the shoreline after 3 years for the vast majority of shoreline oiled following the Exxon Valdez spill,
• The Exxon Valdez Oil Spill Trustee Council concluded that, after 20 years, any remaining Exxon Valdez oil in subtidal sediment is no longer a concern, and that subtidal communities are very likely to have recovered.
• Because sheltered habitats have long recovery times, modern spill response gives high priority to preventing oil from entering marshes and other protected shoreline areas.
• Valued ecosystem components with short life spans can recover relatively rapidly, within days to a few years. Recovery is faster when there is an abundant supply of propagules close to the affected area. For example, drifting larvae from
un-oiled marine and freshwater habitats will rapidly repopulate nearby areas affected by a spill.
• Plankton recovery is typically very rapid.
• Seabed organisms such as filter feeders may be subject to acute effects for several years, depending on location, environmental conditions, and degree of oiling.
• Marine fisheries and other human harvesting activities appear to recover within about 2 to 5 years if the resource has recovered and has not been affected by factors other than the oil spill.
• Protracted litigation may delay resumption of fisheries and other harvesting.
• Local community involvement in spill response priorities and mitigation plans can reduce community impacts and speed recovery of
fisheries and harvesting activities.
• A long life span typically means a long recovery time, in the case of bird and mammal populations that can only recover by local reproduction rather
than by immigration from other areas.
• Fast moving rivers and streams tend to recover more quickly than slow flowing watercourses, due to dispersal of oil into the water column by turbulence, which can enhance dissolution, evaporation, and microbial degradation.
• Drinking water and other water uses can be affected by an oil spill for weeks to months. Drinking water advisories are usually issued. Groundwater use may be restricted for periods ranging from a few weeks to 2 years, depending on
the type of use.
• Groundwater can take years to decades to recover if oil reaches it. Groundwater does not appear to have been affected in the case of Enbridge’s Kalamazoo River spill, near Marshall, Michigan.
• Freshwater invertebrates appear to have recovered within 2 years in several cases.
• Freshwater fisheries may recover fully in as little as four years, with signs of partial recovery evident after only a few months. The ban on consumption of fish in the Kalamazoo River was to be lifted approximately two years following
• Human activities are affected by factors such as cleanup activities, safety closures and harvesting bans. These typically persist for months to a few years.
• Appropriate cleanup can promote recovery, while inappropriate cleanup techniques can actually increase biophysical recovery time.
Modern spill response procedures carefully consider the most appropriate treatment for the oil type, level of contamination, and habitat type.
The Living Oceans Society noted the following in relation to potential recovery of the marine environment following a spill:
• Physical contamination and smothering are primary mechanisms that adversely affect marine life, particularly intertidal organisms.
• Birds and mammals suffer the greatest acute impact when exposed to oil at or near the water surface.
• Marine communities 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,sublethal, and chronic ecological impacts.
• As the return of the marine environment to the precise conditions that preceded the oil spill is unlikely, a measurement of spill recovery can be
based on a comparison of un-oiled sites with oiled sites of similar ecological characteristics.
• The Exxon Valdez oil spill killed many birds and sea otters. Population-level impacts to salmon, sea otters, harbour seals, and sea birds appear to have been low. Wildlife populations had recovered within their natural range of variability after 12 years.
• Intertidal habitats of Prince William Sound have shown surprisingly good recovery. Many shorelines that were heavily oiled and then cleaned appear much as they did before the spill. There is still residual buried oil on some beaches. Some mussel and clam beds have not fully recovered.
• The marine environment recovered with little intervention beyond initial cleaning. Natural flushing by waves and storms can be more effective than human intervention.
• Wildlife rescue and rehabilitation efforts had a marginal beneficial effect on the recovery of bird and mammal populations
• The impacted area of Prince William Sound had shown surprising resiliency and an ability to return to its natural state within the range of natural variability.
• The Exxon Valdez oil spill had significant and long-lasting effects on people and communities.
The Panel posed a series of questions to experts representing Northern Gateway, federal government participants, and the Gitxaala First Nation regarding the potential recovery of marine ecosystems following a large oil spill.
Northern Gateway said that past marine spills have demonstrated that, over time, the environment will recover to a pre-spill state, and that most species fully recover. It said that species associated with the surface of the water tend to be most susceptible to oil spills, and that cleanup efforts can help direct and
accelerate natural restoration processes.
Federal government experts generally agreed with Northern Gateway’s responses, although they stressed that effects could be felt in areas other than the water surface, such as intertidal and subtidal zones. They said that it is difficult to define
and assess effects and recovery, depending on the species and availability of baseline information.
They said that most species may fully recover over time, and that the time frame for this recovery can be extremely variable depending on species and circumstances.
The Gitxaala Nation’s experts noted the potential for effects on species at the water surface and in intertidal areas, and noted exceptions to the notion that
the marine environment will naturally restore itself.
They said that full recovery can occur, depending on the circumstances, but is not guaranteed. They said that it is difficult to assess spill effects in the absence
of adequate baseline information.
Despite the quarter century of studies on the Exxon Valdez inicident, the paucity of studies prior to the spill mean that arguments will continue over “baseline information.”
Participants told the Panel that a lack of baseline information has often made it difficult to separate spill-related effects from those that were caused by natural variation or other causes not related to a spill.
Northern Gateway acknowledged the need for adequate baseline information. Parties such as Coastal First Nations, Raincoast Conservation Foundation, and the Gitxaala Nation said that Northern Gateway had provided insufficient baseline information to assess future spill-related effects. The Kitsumkalum First Nation asked how
spill-related effects on traditionally harvested foods could be assessed in the absence of baseline information.
The Haisla Nation noted the importance of collecting baseline data in the Kitimat River valley to compare with construction and spill-related impacts. The Haisla Nation submitted a report outlining important considerations for a baseline
monitoring program. One recommendation was that the program should engage stakeholders and be proponent-funded. In response to questions
from Northern Gateway, the Haisla Nation noted that a design along the lines of a before/after control/impact model would be appropriate.
In response to these comments, Northern Gateway noted its commitment to implement a Pipeline Environmental Effects Monitoring Program. Northern Gateway’s
proposed framework for the monitoring program indicates that a number of water column, sediment, and biological indicators would be monitored.
The Raincoast Conservation Foundation said that one of the principal lessons learned from the Exxon Valdez oil spill was the importance of collecting abundance and distribution data for non-commercial species. Because baseline information was
lacking, spill effects on coastal wildlife were difficult to determine. Environment Canada also noted the importance of adequate baseline information to
assess, for example, spill-related effects on marine birds.
Northern Gateway outlined the baseline measurements that it had already conducted as part of its environmental assessment. It also said that is
would implement a Marine Environmental Effects Monitoring Program. Northern Gateway said that the initial baseline data, plus ongoing monitoring,
would create a good baseline for environmental quality and the abundance, distribution, and diversity of marine biota. In the event of an oil spill
it would also help inform decisions about restoration endpoints.
Northern Gateway said that it would provide Aboriginal groups with the opportunity to undertake baseline harvesting studies. In response to questions from the United Fishermen and Allied Workers Union, Northern Gateway said that baseline information gathered through the environmental effects monitoring program would also be relevant to commercial harvest management and for assessing compensation claims in the event of a spill.
The Kitimat Valley Naturalists noted the ecological importance of the Kitimat River estuary.
The Joint Review Panel, in its conclusions and ruling, generally agreed with the energy industry that affects of a major oil spill would be temporary.
The Panel heard evidence and opinion regarding the value that the public and Aboriginal groups place on a healthy natural environment.
The Panel finds that it is not able to quantify how a spill could affect people’s values and perceptions.
The Panel finds that any large spill would have short-term negative effects on people’s values, perceptions and sense of wellbeing.
The Panel is of the view that implementation of appropriate mitigation and compensation following a spill would lessen these effects over time. The
Panel heard that protracted litigation can delay recovery of the human environment.
The Panel heard that appropriate engagement of communities in determining spill response priorities and developing community mitigation plans can also lessen effects on communities. Northern Gateway has committed to the development
of Community Response Plans
The Panel’s finding regarding ecosystem recovery following a large spill is based on extensive scientific evidence filed by many parties, including information on recovery of the environment from large past spill events such as the Exxon Valdez
oil spill. The Panel notes that different parties sometimes referred to the same studies on environmental recovery after oil spills, and drew different conclusions. In its consideration of natural recovery of the environment, the Panel focused
on effects that are more readily measurable such as population level impacts, harvest levels, or established environmental quality criteria such as
water and sediment quality criteria.
The Panel finds that the evidence indicates that ecosystems will recover over time after a spill and that the post-spill ecosystem will share functional attributes of the pre-spill one. Postspill ecosystems may not be identical to pre-spill ecosystems. Certain ecosystem components may continue to show effects, and residual oil
may remain in some locations. In certain unlikely circumstances, the Panel finds that a localized population or species could potentially be permanently affected by an oil spill. Scientific studies after the Exxon Valdez spill indicated that the vast majority of species recovered following the spill and that functioning ecosystems, similar
to those existing pre-spill, were established.
Species for which recovery is not fully apparent, such as Pacific herring, killer whales, and pigeon guillemots, appear to have been affected by other
environmental factors or human influences not associated with the oil spill. Insufficient pre-spill baseline data on these species contributed to
difficulties in determining the extent of spill effects.
Based on the evidence, the Panel finds that natural recovery of the aquatic environment after an oil spill is likely to be the primary recovery
mechanism, particularly for marine spills. Both freshwater and marine ecosystem recovery is further mitigated where cleanup is possible, effective, and beneficial to the environment.
Natural processes that degrade oil would begin immediately following a spill. Although residual oil could remain buried in sediments for years, the Panel finds that toxicity associated with that oil would decline over time and would not cause
widespread, long-term impacts.
The Panel finds that Northern Gateway’s commitment to use human interventions,
including available spill response technologies, would mitigate spill impacts to ecosystems and assist in species recovery. Many parties expressed concerns about potential short-term and long-term spill effects on resources that they use or depend on, such as drinking water, clams, herring, seaweed, and fish. The weight of
evidence indicates that these resources recover relatively rapidly following a large oil spill.
For example, following the Selendang Ayu and Exxon Valdez spills in Alaska, fin fish were found, through food safety testing programs, to be safe to eat. Food safety closures for species such as mussels, urchins, and crabs were lifted within 1 to
2 years following the spills.
The actual time frame for recovery would depend on the circumstances of the spill. Until harvestable resources recover, various measures are typically put in place, such as compensation,harvest restrictions or closures, and provision of
It is difficult to define recovery of the human environment because people’s perceptions and values are involved. This was made clear to the
Panel through oral statements and oral evidence.
The Panel finds that oil spills would cause disruptions in people’s lives, especially those people who depend on the marine environment for sustenance, commercial activities and other uses. The extent and magnitude of this disruption
would depend on the specific circumstances associated with the spill. The Panel views recovery of the socio-economic environment as the time when immediate impacts and interruption to people’s lives are no longer evident, and the
natural resources upon which people depend are available for use and consumption.
The Panel heard that assessing the potential recovery time of the environment is often complicated by challenges in separating background or unrelated events from spill-related effects. There can be natural variation in species populations,
and other natural and human-induced effects can also make it difficult to determine which impacts are spill-related and which are not.
The Panel notes that Northern Gateway has committed to collect baseline data and gather baseline information on harvest levels and values through initiatives such as its Environmental Effects Monitoring Program, Fisheries Liaison
Committee, and traditional harvest studies. The Panel finds that these commitments go beyond regulatory requirements and are necessary. This information would contribute to assessments of spill effects on resource harvesting values,
post-spill environmental recovery, and loss and liability determinations.
The Panel is of the view that it is not possible to predict a specific time in which overall recovery of the environment may occur. The time for recovery would depend on the type and volume of product spilled, environmental conditions,
the success of oil spill response and cleanup measures, and the extent of exposure of living and non-living components of the environment to the product spilled. Recovery of living and non-living components of the environment would
occur over different time frames ranging from weeks, to years, and in the extreme, decades.
Even within the same environmental component, recovery may occur over different time frames depending on local factors such as geographic location, the amount of oiling, success of cleanup, and amount of natural degradation.
Based on the physical and chemical characteristics described for the diluted bitumen to be shipped and the fate and transport modelling conducted, the Panel finds that stranded oil on shorelines would not be uniformly distributed on
shorelines and that heavy oiling would be limited to specific shoreline areas. The Panel accepts Northern Gateway’s prediction that spilled dilbit could persist longer in sheltered areas, resulting in longer consumption advisories for intertidal
communities and associated invertebrates than in more open areas.
Based on the scientific evidence, the Panel accepts the results of the
chronic risk assessment that predicted no significant risks to marine life due to oil deposition in the subtidal sediments.
For potential terrestrial and marine spills, the Panel does not view reversibility as a reasonable measure against which to predict ecosystem recovery. No ecosystem is static and it is unlikely that an ecosystem will return to exactly the same
state following any natural or human induced disruption. Based on the evidence and the Panel’s technical expertise, it has evaluated whether or not functioning ecosystems are likely to return after a spill. Requiring Northern Gateway to
collect baseline data would provide important information to compare ecosystem functions before and after any potential spill.
The Panel finds that Northern Gateway’s ecological and human health risk assessment models and techniques were conducted using conservative assumptions and state of the art models. Combined with information from past spill events, these assessments provided sufficient information to inform the Panel’s deliberation on
the extent and severity of potential environmental effects. The Panel finds that this knowledge was incorporated in Northern Gateway’s spill prevention strategies and spill preparedness and response planning. Although the ecological risk assessment
models used by Northern Gateway may not replicate all possible environmental conditions or effects, the spill simulations conducted by Northern Gateway provided a useful indication of the potential range of consequences of large oil spills in
complex natural environments.