Tailings ponds, troublesome externalities, tepid regulations and tipping points; what the Mount Polley Mine tells us about Canada’s environmental crisis.

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Tailings Ponds

It happened early on Monday 4th August. The tailings pond dam at the Mount Polley Mine in central British Columbia gave way. Ten million cubic meters of contaminated water and 4.5 million cubic meters of metals-laden sands and silts washed out into Hazeltine Creek, the outlet for Polley Lake. Hazeltine Creek flows southeast into nearby Quesnel Lake and then through Caribou Creek and on to the Fraser River. The contaminated sands and silts, together with debris scoured out of Hazeltine Creek plugged Polley Lake which rose 1.5 meters behind the unstable, and likely temporary plug. Most of the sands and debris ended up in Quesnel Lake where another large debris field is evident. Timber and other debris ripped from the banks of the Hazeltine Creek was floating about in Quesnel Lake as giant islands and for a time there was concern that one of these would ram into and demolish the only road bridge connecting the small town of Lively to the outside world.

tailings breech Polley mine CBC

Breached dam of the Mount Polley mine tailings pond and the path of destruction down to Hazeltine Creek and Polley Lake. Image © CBC

The tailings pond was about 4 x 4 km in area, a relatively big one. (If the 10 + 4.5 million cubic meters of water and sediments released were giant sugar cubes or Lego blocks they would form a rectangular stack, 100 meters by 100 meters at its base, and soaring nearly 1.5 km high, three times the height of Toronto’s CN Tower or more than 1.5 times the height of the Burj Khalifa.) Tailings ponds are the preferred method for handling mining wastes and the wastes from use of coal, and they do fail from time to time. In Our Dying Planet I wrote of the failure of a containment pond for fly ash generated at the Kingston Fossil Plant, a giant coal-powered electricity generating station near Knoxville, Tennessee. This 4 million cubic meter spill was less than a third the size of the failure at Polley Lake. Of course, the tailings lakes being used in Alberta’s tar sands operations dwarf even Mount Polley; the Pembina Institute reports that 173 km2 of Alberta, an area half again as large as the city of Vancouver, is already covered by tailings lakes, that 25 thousand cubic meters of tailings waste is being produced each day, and that the expected total of contained tailings from tar sands operations will reach 1.3 billion cubic meters by 2060.

Fortunately, it now appears that the water from the Mount Polley tailings pond was relatively free of contaminants although the sediments are likely to include nickel, arsenic, lead and copper. Water samples from Polley and Quesnel Lakes appear safe to drink although a drinking water ban still remains in effect. The contaminant loads in the sediments, however, may be a bigger problem, and cleaning them up will take some time. Water is now being pumped from Polley Lake into Hazeltine Creek to minimize the risk of an uncontrolled rupture of the plug of contaminated sediments and further damage downstream. Some water continues to flow from the tailings pond although the mine staff are working hard to put a temporary dam in place. The mine is in a remote part of the province, so most of the damage that has been done has not affected infrastructure or communities.

Troublesome Externalities

Still, this failure must cause us to think of the many risks that the mammoth scale of resource extraction industries now imposes on the environment and on people. Back when mines were small holes that went deep underground, back when dump trucks stood only three times as tall as a man and carried modest loads, back when tar sands were worthless because we did not have the technology or the capital investment needed to mine them, our impacts on the environment were similarly modest. But we are not back there anymore. Our much greater ability to change the landscape has led to ever grander projects, but we continue to think of environmental damage as something we can repair after the fact if necessary, rather than as something we should absolutely minimize in the first place. We think this way because environmental degradation or damage is just one of those negative externalities that do not enter into the economic assessment of the feasibility of a project. Sure, we have progressed from the old days when rape of the environment, with no effort to minimize damage or undertake any remediation, was the usual approach in all resource extraction industries. Now there is lip-service to the idea that minimizing environmental damage, and repair of any damage caused, should be the norm for all extractive industries – fisheries, forestry, and all types of mining are all managed with regulations that are intended to achieve sustainability (in the case of fisheries and forestry), and avoid or remediate any collateral environmental damage. Industry spends money to comply with the regulations, and some responsible corporations even go beyond the requirements of the regulations in order to more fully avoid environmental damage. But most corporations do their best to minimize these expenses because there is no payback to investors when the extractive operation ends if the environment is successfully put back together. If they do the bare minimum and walk away leaving something less than perfect behind, their investors are not unhappy.

Tepid Regulations

In situations where a major resource extraction operation, or a set of smaller nearby operations, comes to dominate the economic activity in a region, the economic power of the industry is such that it can influence government to minimize regulations, turn a blind eye, or, in other ways, let the industry get by with less effort to minimize or to remediate environmental damage. This is so because governments, the ultimate regulators, also tend to see environment as an externality – they understand the economic (and tax revenue) benefits of profitable industry that employs people far better than the intrinsic but often intangible, and certainly non-taxable, benefits of a healthy, sustainably managed environment. Environment comes second, if it even comes into consideration at all.

This certainly seems to be the case in Alberta’s tar sands district, where the enthusiasm of both provincial and national governments for an expansion of the industry seems to have led to minimal resource rents (Alberta), overly favorable taxation policies for the industry (national), weak regulations (Alberta), lack of enforcement (both), and perennial delays in putting additional or replacement tougher regulations in place (both). This overly compliant attitude by both governments has surely been encouraged by the Canadian Association of Petroleum Producers (CAPP), and individual operators, all of which have ample funds to spend in persuading government regulators to go easy, to go slow, and to give them yet more time to comply. This is all perfectly legal, but it is what happens when the foxes (the mining operators) are helping the farmers (the governments) look after the hen house (the environment).

Oil Pipeline

Tailings lakes in Alberta’s tar sands district. Photo © Jeff McIntosh/Associated Press

In the tar sands district, there are enormous quantities of water being permanently contaminated through use in bitumen extraction. These are stored permanently in tailings lakes, because there is no current technology to clean them up at reasonable cost. This water is effectively being withdrawn permanently from the hydrological cycle, with no evident thought concerning the availability of water in that relatively arid region, or the impacts of those withdrawals on the environment. The Pembina Institute reports that about 11 thousand cubic meters of contaminated water are leaching from tar sands tailings lakes into waterways and groundwater every day. There is solid evidence of pollution damaging to fish and wildlife downstream. The lakes do not appear to be becoming clean by themselves, and the possibility of a tailings lake breach is a continuing possibility (and these tailings are dirty). What future problems for ourselves are we building in northern Alberta?

Tipping Points

One of the over-used phrases when discussing the environmental crisis is ‘tipping point.’ Recognition of the fact that environmental responses to stressors are rarely linear and sometimes rapid, leads naturally to a concern that as we continue to stress the environment, we must anticipate some unexpected, rapid, and perhaps consequential responses. The most frightening ‘tipping point’ in my view is what James Hansen calls ‘runaway climate change’. This is a situation that could arise if we push global temperature high enough to trigger several plausible positive feedback mechanisms that would then essentially take over and continually escalate the rate of warming no matter how much we reduce our own contributions of greenhouse gases. Potential positive feedback mechanisms include the melting of Arctic sea ice, the thawing of permafrost, and the melting of methane clathrates. Melting of the sea ice leaves the Arctic Ocean darker (less reflective) and capable of absorbing (as heat) more of the sunlight that impinges on it. As more ice melts, the rate of warming increases. This is already happening. Thawing of permafrost has the potential to release large quantities of trapped methane (a potent greenhouse gas) formed from decomposition of organic material in the frozen soils. This is starting to happen. Melting of methane clathrates will release more methane, and will happen when the oceans warm sufficiently. There are vast quantities of methane clathrates in the deep ocean and in subsea sediments. Remember the difficulties BP had in capping the Deepwater Horizon blowout. One early attempt with a large steel cone that was to be positioned over the well to funnel the emerging oil into a pipe to the surface failed dismally when methane in the emerging stream of oil combined with seawater to form clathrates which attached to its inner surfaces, plugging its narrow opening to the pipe, and causing the cone to be pushed away by the emerging oil.

Putting aside ‘runaway climate change’ as simply too awful to contemplate for very long, there remain a number of other potential ‘tipping points’ as nature responds to our meddling. The losses of insect pollinators due to our careless uses of pesticides and other chemicals are already having impacts on crop yields, but a tipping point in which widespread crop failure suddenly results is not far-fetched. Unexpected links between climate and insect-borne pathogens might lead to a sudden expansion to new regions of serious diseases like malaria. In much the same way, warming in British Columbia has already permitted a massive northern expansion and early incursions across the Rockies into northern Alberta by the mountain pine beetle resulting in large and growing losses in the BC forestry industry. Coinciding warming and shifts in location, timing and extent of rainfall have already led to severe droughts and floods in many parts of the world, but tipping into a long-term change in regional climate with severe consequences for food production or human health will likely occur and, because of the natural variability of weather, will not be recognized until some years after it happens. Has this already happened in the US Southwest or in western Australia?

Hidden complexity when several factors act together to stress a population

Most insidious of all are the tipping points that occur when seemingly unrelated impacts combine to lessen the chance of an ecological system being able to sustain itself. Some of these are surely already playing out in the oceans, but we are seeing only glimpses of what is going on. As an example of the potential complexity, consider the production of any fishery species. The production of young is a vital task for every population if it is to persist, and heavily fished populations are already stressed by being less abundant than before, and made up of younger organisms. Each individual may have, at best, only one opportunity to reproduce, while its ancestors lived long enough to reproduce in multiple years. Indeed, in the Pacific bluefin tuna, a heavily overfished species, the average individual is caught before it even reaches maturity, yet its ancestors, prior to overfishing, were living 15 years and reaching maturity at five years of age. Thus, overfishing both reduces the number of animals available to spawn, and reduces the number of chances to reproduce by each individual.
While this may not seem very important, limiting the number of chances to reproduce limits the overall total number of offspring that can be produced by each parent, and for organisms like fish that have very high (close to 100%) and very variable mortality in the first few days or weeks after hatching, that reduction in number of chances to reproduce can greatly limit the chance of a fish to get to be a successful parent at all. (It’s a bit like throwing a pair of dice – if you have only one or two chances, the likelihood of throwing a pair of sixes is small, but if you get to throw them 15 or 20 times the odds are much more in your favor for at least one pair of sixes. Think of a fish successfully reproducing as being like you throwing a pair of sixes.)

The typically high and variable mortality of newly hatched and older juvenile fishes is due to a number of factors including the availability of food and how fast they can grow. If there is plenty of food, they will grow faster, become better able to avoid being eaten themselves, and perhaps grow to adulthood. If food is scarce, they will grow slowly if at all, and may starve if not consumed themselves. Either way far fewer of the young fish get to grow up. If the water is warmer, that may increase growth rates directly, but only if food is available. Given this kind of a production system, an adult fish may well need more than one or two chances to reproduce to have any chance of producing young that reach adulthood themselves. This is so despite the fact that fish typically shed thousands of eggs at a time – thousands of eggs, of which nearly 100% usually die before reaching adulthood.

Now consider the prey species consumed by the young hatchlings. These tiny planktonic species must be available to be consumed at the time and place that young fish are present. But their own growth, survival and reproductive success is affected by the environment too. To the direct effects on survival and growth of these small prey species due to warming, or ocean acidification, add in the indirect effects of melting sea ice and glaciers which alter ocean circulation, transporting populations of plankton along different paths than they travelled before. All these factors together act to make the prey more abundant, less abundant, or even absent from a particular location in a particular year. Suddenly, juvenile fish are produced at a time and place that does not coincide with abundant prey to eat. The result is a reproductive failure by the population that year.

Have this happen in just two or three years in a row and that population will decline far more rapidly than would be expected based on overfishing alone (and also far more rapidly than it would if climate change was occurring but the fishery population was not being heavily fished). Mostly we find out about failed reproduction only after the fact, when the new individuals would be large enough to start being caught. Only there aren’t any new individuals. Only rarely do we know the full reasons for why the failure occurred.

MacKenzie et al Fig 5 2007

Figure 5 from MacKenzie et al 2007 showing the complex network of effects of climate change on a) reproductive success, and b) growth in three fishery species: cod, sprat and herring. Climate, by affecting salinity (S), oxygen content (O2) and water temperature (T) has both direct effects (solid arrows) and indirect effects (dashed arrows) on each species, and the pattern of effects on reproduction differs from that on growth. Figure © Global Change Biology

A number of recent reproductive failures of fishery species have been attributed to an absence of the usual prey species (or a shift in their distribution away from where the hatchlings are – which amounts to the same thing). In 2007, Brian MacKenzie and three colleagues, all from Danish research institutions, published a review of impacts of climate change on Baltic Sea fisheries, in the journal Global Change Biology. They showed complex direct and indirect effects of climate-induced changes in the environment (temperature, salinity, oxygen content) on cod, herring and sprat and on the copepod prey species used by their juveniles. That same year, in Fisheries Oceanography, Thomas Brunel and Jean Boucher of IFREMER, France, published a look at long-term trends in reproductive success of fishery species across the northeast Atlantic. They found that ten populations of cod, plaice, whiting and herring showed substantial declines over the period 1970-2000. These were strongly correlated with warming of ocean waters, however the details varied greatly among populations and species. In some, overfishing had a major impact on population size before climate effects on reproductive success began to add to the decline; in others effects on reproduction were paramount. The overall message from such studies is that the success of a fishery population, and hence its availability for capture, depends on a number of different, direct or indirect impacts that include complex effects of climate change as well as impacts from fishing.

Never mind the continued production of a fishery species. Consider the plight of coral reefs around the world. If ever there was a good example of a tipping point, this is it. Reefs have been impacted by humans for many years, through overfishing, pollution, and physical destruction either deliberately to blast out channels or harvest limestone for building purposes, or inadvertently through inappropriate coastal development that lowers water quality, increases turbidity or simply buries living reefs in fine silt. Reefs have also suffered for years. Now, with added pressures due to warming and ocean acidification, and continued overfishing, pollution and physical destruction, reefs in many locations are deteriorating rapidly – a classic tipping point brought about by the synergistic action of multiple stressors each of which might have been far less harmful if it had acted alone.

Coral landscape 3m patch steneck

A coral reef in healthy condition – the way they are supposed to look. Photo © R. Steneck

Tipping Points in the Tar sands?

Still, let’s struggle back onto dry land, because there is a reason I brought up tipping points. I believe our relatively new ability to embark on giant projects causing major changes to environment, even without unplanned events like tailings pond failures, is setting us up for a variety of tipping points in the near future. The tar sands operations in Alberta certainly constitute such a giant project.

There has been a tendency in the long-running debate over the tar sands to deal with issues one at a time. This mirrors the practice of government to evaluate and approve new tar sands projects one at a time. Given the scale of the tar sands industry, and its potential scale in the future if it expands as proponents and governments want, it makes sense to look at all the issues surrounding this industry together – instead of a series of separate potential environmental problems, there is a set of interacting, possibly synergistic problems that are likely to cause unacceptable environmental change. Let’s build a list:


  1. While the products refined from tar sands bitumen yield essentially the same CO2 emissions as those obtained from conventional oil, extracting and refining the bitumen costs about three times the amount of energy (= three times the CO2 emissions).
  2. Much of the energy used to produce the bitumen and upgrade it (make it liquid) for transport comes from burning natural gas, the least polluting of the fossil fuels – good fuel is burned to produce environmentally poor fuel, sort of like using gold to produce lead.
  3. The current scale, and the planned expansion of the tar sands operations are such that executing these plans makes it impossible for Canada to reduce its national CO2 emissions, no matter what adjustments are made in other parts of the economy. Current estimates suggest Canadian emissions will still be higher than 1990 levels in 2020. This puts Canada in an impossible position with respect to other nations, a position which will complicate international relations in ways that are unclear.
  4. Tar sands production is currently being constrained by the lack of capacity to transport the bitumen to refineries and markets. New pipelines and other transport capacity will boost refinery activity and production of refined products, with the result that availability of fuels will increase, prices will fall, and the North American addiction to gasoline and similar fuels will lead to increased use. We will be using more of the environmentally dirtiest oil, at the very time that nations should be weaning themselves off these products. A recent estimate in Nature Climate Change by Peter Erickson and Michael Lazarus of the Seattle-based Stockholm Environment Institute, suggests that approval of the Keystone XL pipeline would unlock about four times the CO2 pollution than in previous estimates, because of this effect on price and use. Yes, it would be worse to transition towards fuels derived from coal, but not much worse.
  5. Tar sands operations have already radically altered 280 km2 of the boreal forest, wetland and lake system of northern Alberta. If they expand as planned some 140,000 km2 of natural habitat could be disturbed. To date, reclamation of terrestrial habitats has been negligible, and techniques for reclaiming the wetlands do not exist. The United Nations Environment Program has included Alberta’s tar sands region among the 100 hotspots of environmental degradation worldwide, and Environment Canada has referred to the “staggering challenges for forest conservation and reclamation”.
  6. The extensive wetlands are an important sink for CO2, storing between 2000 and 6000 tonnes CO2 per hectare. Yet the approved reclamation plans call for most of these wetlands to become upland forests. A 2011 study by Rebecca Rooney and colleagues from University of Alberta, published in the Proceedings of the National Academy of Sciences (USA) reported that the net loss of wetlands from mining ventures approved to that time, is equivalent to the release of 41.8 to 173.4 million tonnes stored CO2, and the permanent loss of the capacity to store 21 to 26 thousand tonnes CO2 per year into the future.
  7. The Athabasca River, nearly 1500 km long, winds from its headwaters in the Columbia icefield in Jasper National Park, through the tar sands district and on to its delta into Lake Athabasca in Wood Buffalo National Park. It is also one of the longest undammed rivers in North America. Its water flow north from Lake Athabasca via the Slave River to Great Slave Lake and thence via the majestic Mackenzie River to the Arctic coast, a journey of about 4000 km. We all know what is happening to glaciers and the rivers they feed. The tar sands industry takes all its water from the Athabasca River or from groundwater sources in the basin. Current permits allow the taking of 349 million m3 water per year, an amount comparable to that used by a city of 2 million people. Unlike in most mining operations, that water is not used, cleaned and returned to the river. It’s used, dirtied, and stored forever in those giant tailings lakes. Flow in the river is already reaching critical low levels for fish populations during the winter months, and it is clear the river cannot supply the ever larger amounts of water a ramping up of tar sands production will demand. What will happen then? The governments have not yet introduced any regulations to limit operators access to water when river flow is low, and existing permits to draw water explicitly permit continued use so long as there is water available to use.
  8. The tailings lakes are already leaching contaminated waters into the Athabasca system. They are acutely toxic to animal life, containing naphthenic acids, for example, at concentrations 100 times greater than natural waters. And nobody knows how, if, or when these waters will be reclaimed.
  9. Air pollution is also a problem in Alberta’s tar sands paradise. Nitrous oxides, sulfur dioxide, volatile organic compounds and particulate matter are all emitted in large quantities from tar sands operations. Modelling of pollution from 6 operations (three in use and three more approved and under development) shows that they will collectively exceed provincial, national and international standards. Releases of benzene are also on the rise, from the burning of fossil fuels in operations and via evaporation from the tailings lakes.
  10. And then there are the pipelines, and the trains carrying explosive tar sands crude. Not only does construction of each pipeline snake across the countryside like a lengthening scar, the pipelines do rupture from time to time, and some, such as Northern Gateway will empty out into previously pristine coastal waters. To get the tar sands product to flow, it has to be diluted with natural gas condensate or similar fluids. Last year’s Lac Mégantic derailment and catastrophic fire showed what could happen to tar sands crude carried by train.

Put these ten issues together and it is clear – tar sand mining as practiced in Alberta is setting us up for any number of tipping points down the road. Meanwhile, our Harper government is spending a fortune of our money advertising the merits of the Keystone XL pipeline and Canada’s ethical oil on the walls of the Washington DC subway.

tar-sands-2-1000 Dodge Pembina

This used to be a productive, carbon sequestering environment of boreal forests and wetlands.
Photo © David Dodge, Pembina Institute.

Meanwhile, back at the Mount Polley Mine, the ban on use of water in Polley and Quesnel Lakes and Hazeltine and Caribou Creeks remains in effect, and Imperial Metals is still working to put temporary repairs in place at the tailings pond. A report in the Vancouver Sun suggests that Imperial Metals’ property and business interruption insurance ($15 million) may fall far short of the expected costs for clean-up, estimated to be in vicinity of $200 million. If that is not enough, production at the mine, now suspended, generates 83% of Imperial Metals’ revenue, and a class-action lawsuit by a group of investors in the company has already been filed. Needless to say, If the clean-up costs more than the deep pockets of Imperial Metals can provide, bankruptcy doesn’t magically repair the damaged environment. That troublesome externality will sit a permanent scar to join all those other scars in other places where industry made mistakes it could not repair.

How long will it take before we know the full extent of the damage? Let’s just observe that on 28th July 2014, over four years after the Deepwater Horizon blowout occurred, Charles Fisher of Penn State University, and 11 colleagues published a report in Proceedings of the National Academy of Sciences (USA) detailing their discovery of five, previously unknown, deep water coral reefs, two of which had been damaged by toxic substances from the blowout or from chemicals dispersed to control it. One of these reefs was 22 km southwest of the site and 1900 meters deep. That greatly expands the footprint of that disaster, both in distance and depth from previous estimates. The damage due to the Deepwater Horizon blowout continues today.

Humans are very powerful, and too often that power damages the fabric of the environment that ultimately sustains us. If there are tipping points in our future, and there probably are, we have put them there because we insist on seeing environmental damage as simply a troubling externality. It’s an externality that we need to internalize as quickly as we can.

Categories: Canada's environmental policies, Changing Oceans, Climate change, Economics, Fisheries, In the News, Tar Sands | Leave a comment

Pacific Bluefin Tuna, Overfishing, and the Anthropocene Defaunation

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Failure to Protect the Pacific Bluefin Tuna

A magnificent creature is going extinct before our eyes because it ranges far and wide across the Pacific Ocean, because it takes too long to grow up before it begins to reproduce, because it tastes far too good, and most of all because we are selfish, unwilling to relinquish the taste sensation or the buckets of money to be made in catching it. It is the Pacific bluefin tuna, Thunnus orientalis. IUCN listed it as ‘Least Concern’ in 2011, and have not yet seen fit to change their view. FAO reports it to be ‘Fully Exploited’ but otherwise scarcely mentions it in the 2014 State of World Fisheries and Aquaculture. The Inter American Tropical Tuna Commission (IATTC), which is supposed to be managing the catch in the Eastern Pacific, met in Lima, Peru, in July, and decided to punt until October, despite a clear recommendation from its scientific staff to reduce the catch in 2014 to no more than the tonnage caught in 2013 (3154 tonnes). (This compares to catches from the Eastern Pacific averaging about 10,000 tonnes per year in the period since 2000.)

PacificBlueTuna5918 CAS MacDonald

Pacific bluefin tuna, Thunnus orientalis, a high-speed, long-distance swimming machine.
Photo © CAS MacDonald

Across the Pacific, abundance of bluefin has fallen to about 4% of pre-fished state, and spawning stock biomass (literally the tonnage of adult fish) is at all-time lows. Recruitment of juveniles also seems to be bouncing along close to the minimum. About 90% of the fish taken are not yet mature – never the best way to harvest a population that is at very low numbers. But, of course, the science can always be questioned, and number of recruits is notoriously variable from one year to the next, so why should the catch be reduced until we are sure there is a problem? Then too, the numbers taken in the East Pacific are just a small part of the total and if catch is reduced there while fishing continues in the West Pacific all that has happened is the East Pacific fishers have lost money.
This is how we fish species to oblivion. By delaying action until we are absolutely certain that there is a problem. By assuming that the behavior of others (in the West Pacific) is the real cause of the problem. By being unwilling to step forward and do the right thing, because we do not want to lose even a tiny bit of income. By holding endless meetings in which we discuss but never reach a conclusion. The Pacific bluefin tuna is simply too tasty, and therefore, pound for pound too valuable to be allowed to continue to exist.

In the 1990 comedy, The Freshman, starring Marlon Brando and Matthew Broderick, the plot revolves around the clandestine Fabulous Gourmet Club, which meets in out-of-the-way venues to serve endangered species to wealthy guests. For a million dollars, you get to eat the last individual of a species going extinct. I remember watching, and thinking, this is not that far from reality! We value rarity, and willingly pay to possess it, whether it be fine art, fast cars, or bits and pieces stripped from the carcasses of rare animals – tiger whiskers, bear gall bladders, dried seahorses ground to a fine dust, rhino horn (also ground), shark fin, or a couple of slices of kuro- or hon-maguro sushi. Unfortunately, no matter how rare each species becomes, there is always somebody willing to acquire one more meal, one more fur, one more medicinal powder, and eventually another species bites the dust.


Matthew Broderick delivers a Komodo dragon to the Fabulous Gourmet Club.
Image © The Freshman, Tristar Pictures

In December 2012, I wrote of the plight of the Atlantic bluefin tuna, which is, if anything, closer to extinction than the Pacific species. What I wrote then about the sheer magnificence of this beast is true also of the Pacific Bluefin, and worth re-reading. So beautifully adapted to living on the high seas, a magnificent swimming machine, an engineering marvel that leaves me in total awe of the power of evolutionary change to sometimes achieve perfection, these are really the ultimate fishes. We are so privileged to share this planet with them that I find it hard to believe we are capable of willingly watching ourselves fish them to extinction. And yet we are. Because they taste too wonderful.

There had been outside pressure on IATTC to act. The Pew Charitable Trust had called upon members, prior to their July meeting, to act decisively on Pacific bluefin tuna because of its perilous status. Predictably, the failure of IATTC to act was met with considerable outrage and high dudgeon. The EU representative was annoyed that nothing much happened at the meeting, but reports suggested the annoyance was more with failure to act on a whole host of items (such as election of a new Director) that the EU favored, rather than specifically at the lack of action on bluefin. The WWF was critical of the failure to act, and has said it will call for a cessation of the fishery if IATTC fails to act in October, and Amanda Nickson, director of global tuna conservation work by the Pew Charitable Trust, was quoted as saying after the meeting,

“Once again, fishing nations have ignored the scientific evidence before them and will allow this decimated population to continue to be overfished, despite dire warnings that it is on the edge of collapse. Pacific bluefin tuna needs an oceanwide recovery plan. This lack of action shows that a suspension of the Pacific bluefin tuna fishery may be the only way to save this species.”

I do not see a suspension of the fishery occurring any time soon. Not until a far greater proportion of humans begins acting ethically instead of selfishly. Nor do I see this case as an isolated instance. We are currently causing an unprecedented thinning out of biodiversity across the planet.

The Anthropocene Defaunation

In the 25th July issue of Science, Rodolfo Dirzo of Stanford University, and five colleagues from the USA, Brazil, Mexico, and UK, published a chilling article, Defaunation in the Anthropocene. In it, they review anthropogenically driven loss in biodiversity since 1500, choosing that year as the start of the Anthropocene, that period in Earth history in which humanity is a major force for planetary change. Their results are not surprising, but they should be concerning. In the past 500 years, humanity has triggered a wave of reduction in abundance, extirpations of populations, and extinction of species that may rival anything seen in any of the five great mass extinction events in Earth’s history. Since 1500, 322 species of terrestrial vertebrates have become extinct, and populations of the remaining species show 25% average decline in abundance.

Invertebrate patterns are equally dire: 67% of monitored populations show 45% decline in mean abundance. (Not mentioned in their article, our impacts on the ocean have been just as severe, with a 90% reduction in biomass of marine fishes commonly cited as the result of our over-enthusiastic fishing.)

As Dirzo and colleagues make clear, while the extinctions, particularly of large, charismatic species, capture the attention, it is the pervasive losses in abundance and reductions of range of individual species that are the most important consequence ecologically. Fewer individuals are available, in fewer places, to play the ecological roles they used to play.

In fact, if we think carefully, most of us can remember a time when there was more life on this planet (and I am not referring to the 1960’s, although they were lively). I particularly remember that back in the days when all gas stations were full service, part of that service was getting your windshield washed. A capable attendant could get the nozzle going, filling your gas tank, and then have time to wash and squeegee your windshield clean before he had to get back to close the tank, hang up the hose and collect your money. Sometimes you got additional cleaning of headlamps and so on. What I particularly remember, back in the day, was that travel in the country, rather than the city, sometimes made it necessary to stop at a gas station before you needed fuel, because you needed your windshield cleaned.

1959 LVC Lambda La Verne Chevron Service

Gas station attendants gave personalized service back in the day. Image © Old Towne Laverne Blog

Flying insects, particularly the big ones that managed to go splat right in front of your steering wheel, were so abundant that the windshield cleaning courtesy was far more than a courtesy. It was a necessity for safe travel. Today, I can drive for hours through farming country and pick up no more than two or three modest little bugs. People of a certain age who watch birds, and particularly those who watch and keep a journal, can tell numerous tales of birds that used to be common but are now seldom seen. In my part of the world, I find the question, ‘have you heard a whip-poor-will lately?’ an effective way to get people thinking about the losses that have taken place. Because this iconic call, that always told a much younger me it was summertime in Ontario, is a call I have not heard for years. The bird is not extinct in Ontario, but it is completely absent from large swaths of former territory.

Dirzo et al Fig 1 large

Four examples from the article by Dirzo and colleagues show the losses in biodiversity being caused by humanity worldwide. A) Large fractions of all the insect species monitored by IUCN are currently declining in abundance. B) Records for British insects of four Orders show from 30 to 60% of species are becoming less widely distributed. C) Globally, an index based on invertebrate species abundance shows that moths and butterflies have declined less severely than other types of invertebrate. D) A meta-analysis of studies of moth and butterfly diversity show the overwhelming majority of disturbed areas hold a reduced biodiversity of these insects. Figure 1 © R. Dirzo, Science

Dirzo and colleagues make the important point that while deforestation is a well-understood term, and an event that is readily apparent and quantifiable in aerial photos of landscapes, defaunation is a far less familiar process to people, and essentially invisible until detailed monitoring studies are undertaken. (Or until someone asks if one has heard a whip-poor-will.) Yet both defaunation and deforestation are vitally important ecologically. They discuss the patterns in defaunation, noting that species are differentially susceptible, and that extent of defaunation varies geographically as well. Among vertebrates, the amphibia have proven particularly susceptible, perhaps because of their dependence on water in the landscape and their sensitivity to chemical pollution. Among mammals, the larger species tend to be most impacted; indeed, mammal faunas show a clear pattern in which the largest-bodied species became extinct by the end of the Pleistocene, a next-largest cohort became extinct in recent years, a next-largest cohort of species is currently threatened and in reduced numbers, and the smallest-bodied cohort seems relatively less affected by us. In general, defaunation has also proceeded more rapidly in the tropics, partly because this is where most species occur, but also because this is where human activities have had the most profound impacts on natural habitats.

Dirzo et al Fig 3 large

Distribution of adult body size varies among mammal species that became extinct during the Pleistocene, became extinct more recently, are currently considered as threatened with extinction, or are currently considered not to be threatened.  Anthropocene defaunation is making mammalian faunas smaller in stature. Figure 3 © G. Dirzo, Science

The main strength of their article, however, is not in how it enumerates the losses of species or reductions in population range or abundance. Dirzo and colleagues summarize the several ecological consequences of this simplification of the biosphere. These include pollination, pest control, nutrient cycling and decomposition, maintenance of water quality, impacts on human health, and the distinct possibility that our defaunation is shaping the evolution of ecological systems in ways that may or may not be to our advantage.

I commented on pollination issues in this blog in April 2013, and attention to the declining abundance of bees has, if anything, grown since then. Neonicotinoid pesticides are among the new weapons we are attacking bees with, and the seed and pesticide agribusinesses are playing the ‘evidence does not absolutely confirm neonicotinoids are to blame’ game used by every business on the planet that wants to continue with practices that obviously damage the biosphere. Dirzo and colleagues simply state that 75% of all our crop plants require insect pollinators, and that the pollination service is estimated to be worth 10% of the economic value of our global food supply. They then report that pollinators appear to be declining strongly, both in abundance and diversity, across the globe.

Small vertebrates play a major role in controlling the abundance of smaller, usually insect or other invertebrate, pests. Experimental or observational studies have found that removal of small vertebrates from a site leads to a broad range of adjustments to the composition of the animal community as prey species become more common, and inflect more damage on plants or their own prey organisms. Such ‘trophic cascades’ are a feature of any ecological system that is disturbed by removing an important predator. Dirzo and colleagues report that arthropod (mainly insect) pests are typically responsible for destroying 8 to 15% of crop yields, and that reduced abundance of small vertebrates could see this damage rise to 37%. In North America alone, they peg the value of pest control by small native vertebrates at $4.5 billion annually.

Comments in the article on effects on human health were particularly chilling. Defaunation, by reducing diversity, reduces the provision of numerous goods and services, including sources of pharmaceutical compounds, biocontrol agents, food resources, and disease regulation. Between 23 and 36% of all birds, mammals, and amphibians used for food or medicine are now threatened with extinction. In addition, wildlife provides important food resources in many societies, and loss of abundance deprives people of needed food. One estimate suggests loss of wildlife in Madagascar will lead to a 30% increase in anemia with resultant increases in mortality, morbidity and learning difficulties. While Dirzo and colleagues stuck to terrestrial fauna, the collapse of coastal artisanal fisheries is increasing the challenges for the very poor in many tropical countries, yet current trends suggest we are proving inept at preventing this degradation.

Dirzo and colleagues end their review with a warning that “cumulatively, systematic defaunation clearly threatens to fundamentally alter basic ecological functions and is contributing to push us toward global-scale ‘tipping points’ from which we may not be able to return.” Then, they plead for a more meaningfully attack on “immediate drivers of defaunation” stating that

“mitigation of animal overexploitation and land-use change are two feasible, immediate actions that can be taken. These actions can also buy necessary time to address the other critical driver, anthropogenic climate disruption. However, we must also address the often nonlinear impacts of continued human population growth and increasingly uneven per capita consumption, which ultimately drive all these threats (while still fostering poverty alleviation efforts). Ultimately, both reduced and more evenly distributed global resource consumption will be necessary to sustainably change ongoing trends in defaunation and, hopefully, eventually open the door to refaunation.”

I came away feeling that their recommendations for action were unlikely to achieve very much, and that until people realize the true extent of the 6th mass extinction, we are unlikely to change our ways. But then, that is true for virtually every aspect of the global environmental crisis we face. Until a sufficient number of us wake up and look around, nothing much is going to get done and the problems will continue getting worse. Surely that sufficient number must be just around the corner?

forest fish bee reef

We will find our way once we comprehend that the trees are worth more than the timber, the bluefin are worth more than the sushi, the bees are worth more than the honey, and the reefs are worth more than the limestone.

Categories: Biodiversity Loss, Fisheries, In the News | Leave a comment

Cumulative Effects, Synergistic Stressors, and the Decline of Coral Reefs

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The Coral Reefs of the Caribbean

Dr. Thomas F. Goreau, who died in 1970 at just 45 years age, was a pioneer coral reef ecologist who began studying the reefs of Jamaica in 1951.  A faculty member at the University of the West Indies, he established the Discovery Bay Marine Lab, which still operates on the mid north coast of the island – one of the oldest research facilities in the Caribbean.  Many reef scientists got their start as graduate students working at Discovery Bay, and some of these have gone on to make great contributions to coral reef science in their own right.  One of these, Dr. Jeremy Jackson, just published a report on the decline of Caribbean coral reefs.  But I am getting ahead of myself.

In 1959, Tom Goreau published an article in the journal Ecology, titled “The ecology of Jamaican coral reefs, I. Species composition and zonation.”  It was illustrated with gorgeous underwater and aerial photographs that are unfortunately grainy messes in the pdf versions of his paper that I can now download from the web.  They are photos of another world in two very real senses – a world so very different to the high-and-dry world that most of us inhabit all our lives, and an underwater world totally unlike that at any location that now exists in the Caribbean.  It was a world of magnificent coral architecture stretching for miles along the coast of Jamaica.

Coral reefs grow in a more-or-less typical form  comprising at its simplest, a wide but very shallow reef flat with some living but lots of dead coral, a reef crest, the highest point facing the breaking waves, and a reef slope that may be divided into several zones covering different depths.  In the beginning, which for coral reef science means the mid-20th century, corals were so abundant on typical Caribbean reefs, that when people like Tom Goreau set out to describe reefs, they gave names to most zones in the structure of the reef based on the dominant coral species present.  Thus, Goreau recognizes the ‘reef flat’ or Zoanthus zone, the palmata zone, the buttress zone, the cervicornis zone and the annularis zone.  Goreau wrote of the palmata zone:

In the upper, or breaker, region of this zone, the Zoanthus overgrown reef flat abruptly gives way to a narrow zone which is populated almost exclusively by huge tree-like colonies of Acropora palmata that take the full force of the surf.  The great serried outliers of this coral are predominantly oriented in the direction of the prevailing seas which thus give the whole zone the characteristic appearance of a great jagged comb with irregular teeth. ….. In front of the breaker zone, the reef slopes gently downward to depths of between 5 and 6 meters. …..  Acropora palmata is still the dominant coral, growing in large isolated heads that also are strongly oriented into the prevailing seas.”

A palmata by sailn1-flickr

Imagine miles of reef front composed of a magnificent rampart of Elkhorn coral (Acropora palmata), a species now on the Endangered species list.  Goreau’s reefs no longer exist.  Photo © sailn1/flickr

Notice his phrasing – “huge tree-like colonies,” “great serried outliers.”  Elkhorn coral (palmata’s other name) can indeed be giant and tree-like, with stout branches as big around as a human arm or leg, soaring upwards before fanning out to create archways as much as one to two meters high, and sometimes spacious enough that a careful diver can squeeze in between.  Treelike indeed, and in great serried ranks stretching along the coast as a giant barrier protecting the shore from incoming waves.  Elsewhere in the article, Goreau refers to “the extensive proliferation of Acropora palmata that is so characteristic of the upper zones of West Indian reefs.”  He also talks about the buttress zone having its surfaces almost 90% covered by living corals, and refers to the “immense beds of staghorn coral, Acropora cervicornis” that typify the “cervicornis” zone.  From his words and his pictures comes a clear picture of a place dominated by colonies of living corals, a living architecture that provides the background to the lives of all those other creatures one expects to find on a coral reef.

Several of the scientists featured in Reef Reminiscences describe the Caribbean reefs they remembered, using similar phrases, and Judy Lang remembers her time at Discovery Bay as a young graduate student working with Tom Goreau.

Fast forward to 2014, and the new IUCN publication authored by Jeremy Jackson.  It begins by quoting well-known senior marine scientist, Sylvia Earle, who wrote in 1972:

Perhaps the most striking aspect of plant life on a coral reef is the general lack of it.  It seems anomalous to even the casual observer that tropical reefs, notable for their dazzling profusion of animal life, are almost devoid of conspicuous plants.

It then states, “Sylvia Earle’s early observations upon Caribbean reefs describe a forgotten world. Caribbean coral reefs have suffered massive losses of corals since the early 1980s due to a wide range of human impacts including explosive human population growth, overfishing, coastal pollution, global warming, and invasive species.  The consequences include widespread collapse of coral populations, increases in large seaweeds (macroalgae), outbreaks of coral bleaching and disease, and failure of corals to recover from natural disturbances such as hurricanes.”

Status and Trends Caribbean 2014

Cumulative Effects

Welcome to the world of cumulative effects.  That phrase refers to the fact that different stressors acting on an ecological system have a total effect that is larger than the effect of any single stressor.  For example, the impact of one hurricane on an otherwise healthy coral reef will be some degree of physical damage, the extent of which depends on storm intensity, tidal phase and direction of storm travel at the time of impact.  That damage can be repaired by regrowth of corals in following years.  A succession of hurricanes of similar strength, hitting the same reef over a several year span will cause greater damage, and might even hammer the reef to rubble – each successive storm will further damage an already damaged reef structure.  Similarly, if a reef is subject to pollution from coastal agriculture, damage will be caused, and a hurricane will further damage this reef.  In each case there are cumulative effects.

Sometimes the cumulative effects are no greater than the sum of the impacts of each of the stressors, but the stressors may also act synergistically, meaning that one affects the degree to which the other has impacts.  For example, the pollution may weaken the reef, making it more susceptible to the physical damage caused by storms than it would otherwise be.

Caribbean and all other coral reefs have been suffering cumulative effects of human activities for a long time.  Overfishing removes organisms with important ecological roles, such as the parrotfishes that graze algae and scrape away at dead and living corals to generate newly exposed, clean rock surfaces that may be particularly suitable settlement sites for new coral larvae.  Pollution from domestic and agricultural run-off adds nutrients that favor growth of algae that may in turn smother corals, shade them out and ultimately kill them.  The pollution may also make the corals more susceptible to diseases.  Destruction of reefs through inappropriate coastal development, fishing using traps or explosives, anchor damage, and coral mining for use in construction projects, may further damage already damaged reefs, or may happen at rates that exceed the reef’s capacity to repair itself through new coral growth.

The story of Caribbean coral reefs is a textbook example of cumulative effects in operation, and the depressing results are there for all to see.  Jackson and colleagues report the results of a careful analysis of the various monitoring data from across the Caribbean and from the early 1970s until now.  Despite differences among data sets in data quality or sampling methods that make an analysis much more difficult, they have been able to develop a reasonably precise estimate of the extent to which coral cover has declined, and to examine the different patterns of decline from place to place across the region.  Coral cover across the region, based on the most recent data available is now on average 14.3%.  Abundance of various fleshy algae (nearly absent in Goreau’s time) has grown to an average of 24% coverage of the reefs over the same period.  Coral cover has declined from an average of 34.8% during 1970-1983, to 19.1% during 1984-1998, and to 16.3% during 1999-2011.  The variation among locations is large, both in pattern of decline through time and in overall extent.

As the graphs below show, the pattern of decline was steep prior to 1984 for nine well-studied locations from the Dry Tortugas to Costa Rica including five sites within Jamaica, with little change after that time (Graph A).  The decline was almost linear across the full time period at five other locations in the Virgin Islands, Mexico and the northern Florida Keys (Graph B), and was essentially non-existent at seven locations, five along the southern boundary of the Caribbean and one each at the Flower Gardens Bank in the northern Gulf of Mexico and at Bermuda well to the north.  Clearly, the loss of coral cover has not been uniform across the Caribbean.

Status & Trends Fig 4 A-C

Status & Trends Fig 4 D resize

Figure 4 from the IUCN report, Status and Trends of Caribbean coral reefs, 1970-2012, showing in Graphs A, B, and C the different patterns of coral loss at 21 well-studied sites located at the sites shown across the Caribbean.  Image © IUCN.

The lack of consistency in pattern is not surprising.  The relative intensity of such stressors as overfishing, pollution, and physical destruction varies from place to place, and the reefs themselves are in different oceanographic settings – close inshore, near a polluting river mouth, bathed by clean oceanic water, facing or protected from prevailing winds.  The cumulative effects, not surprisingly, also differ.

The report evaluates the various stressors, and possible interactions among them.  For example, certain coral diseases have been of major importance in Caribbean reef decline, and have virtually wiped out Elkhorn and Staghorn coral (they are both on the US EPA Endangered Species List).  There is some scientific evidence suggesting synergy: diseases appear to have been facilitated by the exuberant growth of algae and/or by pollution.  This is also the first major report I have seen to make the case that in some places tourism has had significant negative effects on reefs.  Overfishing is particularly interesting, because it may be that the removal of important grazers, particularly the parrotfishes, has facilitated the growth of algae that in turn has contributed to the loss of coral through competition for space on the reef, and inhibition of settlement of new coral larvae.  The effects are not only cumulative, there are many of them and they seem to be interacting in complex ways.  Naturally, the chief cause of coral decline in the Caribbean is our growing numbers, and growing desire to live near, and make use of reef systems.

One result that is at first surprising is that, in the Caribbean, bleaching and subsequent coral death due to the warming of climate change has been of less importance than several other stressors.  There is no doubt that bleaching damage has been important at some locations, and scientists expect that bleaching, together with ocean acidification, is going to become a more important stressor over the next decades as we further warm up the climate, but up to now it has played only a small role in this part of the world.

Dumbing Down the Story

The IUCN report does a generally good job of reviewing the evidence for each of the stressors in turn, and makes the point clearly that Caribbean coral decline has been a complex process with multiple causes that vary a lot from place to place.  Unfortunately, when it came to writing the summary for the report, and even more so, when it came to writing the press release, the people at IUCN made the common mistake of dumbing down the results, focusing on only a couple of stressors, and suggesting (unless the words are read very carefully) that all we have to do is to begin protecting parrotfishes and coral reefs will recover.  Naturally, the media dumbed the message down even further – coral reefs are degrading because we have been overfishing parrotfishes.  And the climate change deniers grabbed the few sentences on climate change to trumpet that the worldwide decline of coral reefs had everything to do with overfishing parrotfishes, and nothing to do with CO2 pollution.

Global Coral Decline

So let me say it once more.  Cumulative effects are real.  The global decline of coral reefs is a classic example of the consequences of cumulative effects, and has different causes from place to place.  In the Caribbean, climate change induced coral bleaching has been one of the causes, but not a major one until now.  A number of other factors have been more important there until now.  These include the overharvesting of parrotfishes, and if we begin protecting parrotfishes that should be helpful.  Paradoxically, if the many marine protected areas (MPA) throughout the Caribbean had been properly managed, so that fish within their boundaries largely escaped fishing pressure, we would be able, today, to see the extent to which protecting parrotfishes could help reefs.  Instead, of course, most Caribbean MPAs are only really protected on paper, as are far too many MPAs around the world, and fish inside their borders suffer from overfishing just as do fish living outside their boundaries.

I’ve written before about the report in Science in 2012, in which Glenn De’ath and colleagues used a 27-year long data set to evaluate extent and causes of change in coral cover on the Great Barrier Reef.  Their results were equally as depressing as those in Jeremy Jackson’s IUCN report.  Cumulative effects were again in evidence, but the three main stressors were cyclones (hurricanes), outbreaks of the Crown-of-Thorns starfish which feeds on living coral, and bleaching due to climate change.  I earlier discussed how humans had a partial role in two and perhaps all three of these.

These relatively recent results for the Great Barrier Reef and the Caribbean represent the two best surveys of coral decline over large geographic regions.  There is nothing to my knowledge to suggest that most other regions of the world are not suffering similar patterns of coral decline, and I anticipate that cumulative effects are evident in every location.

There is one more thing to say before leaving this topic.  If we want to restore coral reefs, in the Caribbean or anywhere else, we have to take action to reduce the impacts of at least some of the stressors acting.  We have to take real action, not plan to take action, not pass legislation or write new regulations.  We have to actually take action to alter our behavior around reefs.  This is good news!  Because it means there are actions we can take that will make a difference.  It’s not rocket science, but it does take a real commitment.

We have a serious problem that can be mitigated if we want to do so, because most of the stressors act locally.  While it is going to require major international action to reduce CO2 pollution, better regulation of fishing, of pollution, of coastal development, and of tourism can all be done locally, on single stretches of coast, where the community and the government want to make a difference.  It’s a serious problem, but a very fixable problem!  But not fixable if we only pretend to act, or if we grab at one cause only and run around telling people that saving parrotfishes will save the reefs.  It is really time now to get real.  Do we really want to save some of the world’s coral reefs?

Adding to the Cumulative Effects

One thing we should not be doing is adding to the cumulative effects.  Unfortunately, in Australia right now that is precisely what government action seems destined to do.  Australians value their Great Barrier Reef.  It is well managed at considerable annual cost, and it generates far more than it costs in the tourism it drives year by year.  It is a UNESCO World Heritage Site, recognized around the world.  I thought it was in safe hands.

This was not always the case, and I describe in Our Dying Planet how Australians changed their attitude to the reef and to the environment in general during the mid-70’s, all because a tiny NGO called the Queensland Littoral Society produced a bumper sticker with the slogan, Save the Barrier Reef.  That slogan led ultimately to legislation banning oil prospecting over reef waters, and to the formation of the Great Barrier Reef Marine Park and the Federal Agency that manages it in close cooperation with the Queensland state government.  I have long claimed the Great Barrier Reef to be the best example of reef management in the world.  It has a strongly science-based management process.  Among notable achievements, it now has 33% of its area protected as no-take fishing exclusion zones, and managers have been able to work with agricultural interests to modify the farming practices along the length of Queensland to reduce fertilizer and pesticide run-off and restore water quality for reefs hundreds of kilometers away from the nearest sugar cane fields.  That kind of reach beyond the borders of the area of jurisdiction is very rare in the world of marine protection.


A bumper sticker which saved the Great Barrier Reef in the 1970s.  Image © AMCS

But Australia is also a nation rich in coal and other mineral deposits and resource exploitation and export is a major component of the economy.  A significant battle has been going on over the past few months because the ‘need’ to expand port facilities to export more and more coal to China has run up against the need to protect the Great Barrier Reef.  The change of government, late last year, bringing a climate change dismissing (if not denying) government to power in Canberra has tilted the playing field back in the direction of coal and away from conservation.  In unrelated legislative activities, Australia has just cancelled its carbon tax – a backward move that may be substantially more serious than Canada’s abrupt withdrawal from Kyoto several years ago.

I started noticing media reports at the start of 2014.  An article in the Sydney Morning Herald for 4th February reported that plans called for an increase in coal exports from 240 million tonnes in 2013 to 787 million tonnes in 2030.  To do this will require expanded and new shipping terminals along the Queensland coast – and that means inshore of the Great Barrier Reef.  A report released by the Australian Marine Conservation Society early in 2014, Dredging, Dumping, and the Great Barrier Reef, identified nine port construction or expansion projects being planned.  While the dredging planned at Cairns is in order to permit entry of larger cruise ships, the others all relate to the coal export industry.  They range from Cape York in the far north of the reef to Gladstone at its southern end – they could not be more widely distributed along its shoreward side if they had been explicitly designed to be so.  The report estimates a total of 83 million m3 (or 149 million tonnes) of material to be dredged and then dumped offshore, but still within the Great Barrier Reef region (there is lots of open space between and inshore of the reefs).  The Guardian commented on the situation on 7th May, drawing attention to the mining industry’s claim that coral decline has been caused by bleaching, Crown-of-Thorns, disease, and cyclones (quoting De’ath’s article), and inferring therefore that dredging does no damage (the logic of mining companies is sometimes a bit shaky).  Dredging planned for the future is not going to show up as a cause of coral decline in the past unless Australia exists in a really unusual universe!  The Guardian article also mentioned a study of effects on corals of smaller scale dredging at one of the ports, and the inadequacy of the methods used to assess possible damage – needless to say, the mining industry quite likes to reference these inconclusive data.

New Scientist for 26th May carried a short article by Dr. Jon Brodie of James Cook University that looked specifically at one port – Abbott Point, currently the most northerly coal port on the Queensland coast, located 25 km north of the town of Bowen, and slated for expansion requiring 5 million tonnes of sediment to be dredged and dumped further offshore (but still inside the reef).  Brodie notes that when the plan was announced, the Environment Minister, Greg Hunt, stated that the project would not reduce water quality over the reef.  This is because the approval requires that the impacts due to sedimentation by the dredged material be ‘offset’ by improvements to agricultural practice to reduce sediment run-off in two nearby rivers.  As Brodie noted, to fully offset the delivery of 5 million tonnes of sediment requires that the waters of those rivers must have their sediment loads cut by 5 million tonnes of sediment.  Unfortunately, they carry only 6 million tonnes a year, so cutting that by 5 million becomes “a tall order”.  I’d call the pretense that this is a solution a tall tale.

Recently, a post on coral-list by Dr. Terry Hughes of James Cook University alerted me to two recent articles from that institution that are relevant to the issue.  The first, by Joe Pollock and seven colleagues from James Cook University, Australian Institute of Marine Science, and other institutions in Western Australia and Queensland, was published in the open access journal, Plos One, on 16th July.  Their study, funded as part of the required environmental impact assessment process, was a detailed study of coral health and survivorship at different distances from a sediment plume caused by dredging for another resource development project, the giant Gorgon gas project on the Pilbara coast of Western Australia.

Fig 1 Pollock resize

Figure 1 from Pollock’s article showing the incidence of diseased (red) or compromised (green) corals at sites exposed to the sediment plume and at sites away from the plume.  Numbers indicate number of days exposure to sedimentation.  Image © Plos One

Dredging for that installation amounted to some 7.6 million tonnes of sediment over an 18 month period from May 2010 to November 2011.  Their results show clear impacts of the sediment plume on coral health.  Primarily, corals exposed to the sediment plume suffered greater incidence of a suite of coral diseases.  In addition, the prevalence of a number of other morbidity factors was increased.  Tissue necrosis was 57 times more likely at sites within the sediment plume, and bleaching, overgrowth by sponges, and changes in pigmentation also increased.  Their conclusions are quite explicit:

This study provides the first empirical evidence linking turbidity and sedimentation with elevated levels of coral disease and other indicators of compromised coral health in situ.  We found two-fold higher disease prevalence, largely driven by increases in [‘white syndrome’, a common disease], and six-fold higher levels of other compromised health indicators at high sediment plume exposure sites.  Since these in situ health assessments were conducted more than 18 months after commencement of dredging, it is likely that the most susceptible corals experienced complete mortality prior to surveys being undertaken.  Therefore, these prevalence figures likely underestimate the true impact of dredging-associated sedimentation and turbidity on coral health”.

The second study, by Kathryn Burns of James Cook University, was published in Estuarine, Coastal and Shelf Science, and directly concerned the sediments being dredged within the Great Barrier Reef.  She examined samples of the sediments, and of material collected from the sediment plume caused by dredging at Hay Point, off Mackay, Queensland.  Looking for PAHs (polynuclear aromatic hydrocarbons – some of the nastier chemicals out there) she found ample evidence that PAHs derived from coal dust were in the sediments being deposited from the plume well out to sea and towards the outer Great Barrier Reef.  Her conclusions were also explicit:

The data shown here demonstrate that the coastal sediments offshore of the Hay Point coal port are already contaminated with coal residues which exceed the ANZECC/ARMCANZ (2013) toxicity guidelines and approach toxicity values under the US EPA guidelines.  If the US EPA guidelines had included the biphenyl and dibenzothiophene series which are also present in samples then calculated toxicity values would have been higher…”

Putting this all together, we have evidence that extensive dredging is going to damage the Great Barrier Reef through impacts on water quality, and that turbidity, smothering due to sedimentation, and noxious chemicals all play a role.  But we also have evidence that the industry and the government want to expand those coal ports, and are willing to claim there will be no damage to the reef.  The Australian government is playing the same ‘economy’ and ‘jobs’ cards being played by the Harper government in pushing expansion of Canada’s tar sands industry.  And the science and conservation community are doing their best to be heard.

Let’s Close with Some Good News

On 24th May, we learned that the HSBC bank had followed the lead of Deutsche Bank, and decided not to fund the expansion of port facilities at Abbot Point, citing unacceptable social, environmental and financial risks to investors.  Put into plain English, neither bank wants to risk its reputation by investing in a project that will damage the Great Barrier Reef.

On 20th June, Reuters reported that the Dudgeon Bay project, a new port facility near Hay Point intended to handle 180 million tonnes of coal a year, had been put on hold indefinitely.  The developers claimed that lower than anticipated prices for coal meant that demand for export facilities would not be sufficient to justify the expense.  It’s also possible they were just getting cold feet.

I do not, for one moment, believe this battle is over yet.  A number of port expansions remain in play, and the Australian government has certainly not seen any reason to slow down the rush to dig up and export every thing of value from Australia …. Boy, that does sound a lot like Canada, doesn’t it!

However, there is one more tiny bit of good news.  That tiny NGO, the Queensland Littoral Society, with its simple slogan, Save the Barrier Reef, that really did save the Great Barrier Reef back in the 70’s…. it changed its name a few years ago, and is now the Australian Marine Conservation Society.  It’s the same people!  You can read about its history on its web-site while you download its report on dredging.  It is still out there, saving the barrier reef.  With that kind of long-term commitment and dedication, and with the efforts from the science community to get the truth out about likely impacts, there is a good chance the reef can be saved yet again.

Putting this news about the Great Barrier Reef together with the story of coral decline in the Caribbean, I feel strangely invigorated.  Even though the threats due to climate change and ocean acidification still hang over coral reefs worldwide, there are many other stressors acting, and most of these are local.  It is possible to make a real difference now, by acting on each of these local stressors, by cutting pollution and by saving parrotfishes, by curtailing unwise coastal development and regulating tourism firmly.  A good start might be simply to protect all those unprotected MPAs around the world, while speaking out forcibly about any new projects to add to the difficulties faced by coral reefs.  Cumulative effects require cumulative efforts to stem the tide and prevent us from killing the reefs.  They are worth caring about.

A palmata by seestjohn-com

Fish sheltering under Elkhorn coral, St. John, USVI.  Photo © Gerald Singer

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