Seascapes on the Scotian Basin (Photo by Simon Ryder-Burbidge.) Seascapes on the Scotian Basin (Photo by Simon Ryder-Burbidge.)

This article is Part II of a two-part series on the challenges of cleaning oil spills. In this installation, A\J looks at ‘synthetic-based mud’ spills in the North Atlantic and the dangers they pose to marine ecosystems. Part I, on using patience and restoration measures to heal contaminated terrestrial ecosystems, can be found here.

On June 22, 2018, British Petroleum, the London-based energy firm responsible for spilling more than 700 million litres of oil into the Gulf of Mexico in 2010, made the news again for another marine spill, this time off the coast of Nova Scotia.

A bulletin posted by the Canada-Nova Scotia Offshore Petroleum Board (C-NSOPB) reported a 136,000 litre discharge of “synthetic-based mud” into the Atlantic Ocean over the course of several hours. The BP spill was instantly one of the largest ever in Atlantic Canadian history. It occurred at a site known as Aspy D-11, just two months into the company’s recently approved Scotian Basin Exploration Drilling Project.

Placed more than 300 kilometres east of Halifax, and just south of Sable Island, the Aspy D-11 project covers several thousand square-kilometres of ocean basin and aims to explore a handful of other deepwater wells at about 3,000 metres below the surface. By 2020, the company expects to wrap up production.

In its official statement on the mixture dumped into the North Atlantic, the C-NSOPB noted the mud is “used during drilling to lubricate the drill pipe.” It’s heavy, they reported, and dense. And because of its weight, the lubricant sinks rapidly down the water column before settling on the seafloor. The Board also categorized the spill as essentially harmless, calling the escaped substance a “low toxicity” fluid.

The “mud” BP spilled into the Atlantic last month is comprised of a highly specialized mixture of oil, water, enriched organic material, and other chemical compounds. The primary component, accounting for upwards of 65 per cent of the drilling fluid, is a Petro-Canada concoction known as PureDrill TM/MC IA-35, used widely in Canadian offshore operations.

Petro-Can describes PureDrill as a clear, odourless liquid. It’s near fatal in high doses, leading regulators to add a stipulation to PureDrill’s Safety Data Sheet suggesting users wear respiratory protection when handling it and contact a poison specialist immediately if ingested. Offshore, this potent slurry is mixed with water and other elements and set to ease friction during the drilling process.

It’s heavy, they reported, and dense. And because of its weight, the lubricant sinks rapidly down the water column before settling on the seafloor.

While we humans can affix respirators to our faces to protect ourselves from the harmful effects of PureDrill, marine animals have no such luxury. And the substance’s impacts on aquatic life are poorly documented, let alone the at a release rate of 136,000 litres in less than a day.

In response to a flurry of public questions and concerns related to fisheries and ecosystem impacts, C-NSOPB posted 73 seconds of video of the seabed at the Aspy D-11 well area online. Produced as part of a routine pre-drill marine survey, the footage shows brief clips of several benthic areas stitched together, appearing to show actual mud, not the PureDrill-laden kind, at the bottom of the ocean.

Although the setting appears sparsely populated in the video, a report drafted on April 16 by the consulting firm Stantec documented the presence of a variety of deep-sea inhabitants. Analyzing data from a remote operated underwater vehicle that scanned the seabed for 500 metres in all directions from the wellhead, Stantec’s marine scientists, found signs of brittle stars, sea cucumbers, shrimp, glass sponges, and several species of fish.


There is a wide variance in the literature that does exist on the marine impacts of synthetic drill fluids, often diverging across fluid types, release rates and benthic habitats. Because synthetic-based mud (known in the industry as “SBM”) relies on an unusually heavy liquid mixture, the discharged products sink quickly. While this means SBMs don’t spread across the surface of the water as pure crude oil does, as witnessed in BP’s other notorious spill in the Gulf of Mexico, it also means the mud cannot disperse, gathering instead at the seabed.

Rather than coat the top layer of the water column, these synthetic muds blanket the ocean floor in a thick film of toxic fluid — in some cases enough to smother marine species directly below. In 2004, another spill of a similar size to the Aspy D-11 spill occurred at the White Rose well off the coast of Newfoundland, contaminating ocean sediment upwards of six kilometres from the wellhead.

Husky Energy, the fossil fuel mega-corporation responsible for the damage at White Rose, reported a decreased abundance of benthic invertebrates at sample sites close to the drilling location, several of which were identified as toxic to local plankton populations – a microscopic plant-based lifeform crucial to the deep sea food chain. Further biological tests on snow crab and American plaice showed slightly elevated levels of iron and zinc, though ultimately Husky claimed any health effects on these commercial species were negligible. Causation was not described in the report. Husky called the spill’s overall ecological impact “limited.”

Meanwhile, the repercussions for operators like BP and Husky who oversee such significant chemical spills in Atlantic Canada are effectively non-existent. Just three years after Husky’s 2004 disaster, which released 96,000 litres of toxic drilling fluid into the surrounding sea, the Canada-Newfoundland and Labrador Offshore Petroleum Board (C-NLOPB) found the Calgary-based firm guilty of two counts of non-compliance with Canadian offshore drilling guidelines. Their punishment? C-NLOPB levelled a $70,000 penalty against Husky and ordered them to make a $30,000 contribution to Canada’s Environmental Damages Fund.

That year, Husky pulled in over $15 billion in revenue.


Husky and BP are far from alone when it comes allowing tens of thousands of litres of chemical-laden sludge to seep into Canadian waterways.

Newfoundland and Labrador has a long history of drilling in deepwater, stretching back to 1997 when its first well was popped at the Hibernia drilling site, several hundred kilometres east of the capital at St. John’s. In the two decade since, the C-NLOPB has recorded 527 spills in the area, ranging widely in volume and source.

The largest of these incidents came from Petro-Canada when 165,000-plus litres of pure crude were spilled from the Terra Nova well the same year Husky allowed 96,000 litres of synthetic-based mud to escape at White Rose. Much like Husky, Petro-Canada, a multi-billion-dollar, one-time crown corporation owned by Suncor Energy since 1990, received a $70,000 slap on the wrist and continued its operations in the North Atlantic.

According to the Canada-Newfoundland and Labrador Offshore Petroleum Board’s annual reporting, major blowouts have occurred on the watch of Chevron, Statoil, Alton Gas and Suncor. All have been the recipients of equally trivial penalties from the C-NLOPB, when indeed the spills were prosecuted at all.

Many prosecutions are passed to public legislators and held up in court for years; some never see the light of day. Taken together, these multi-billion-dollar fossil fuel entities spill and spill and spill and yet they continue to rake in massive profits at the expense of the Atlantic Ocean, a resource all Canadians share and that future generations will depend upon for sustenance, culture and economic livelihood.

The Skandi Vinland, a Canadian offshore supply vessel is pictured here in the St. John’s Harbour. A huge economic driver for the Newfoundland and Labrador, offshore oil has been a major boon to provincial economy. (Simon Ryder-Burbidge)

But spills are only one part of the story. Over the duration of any drilling initiative, by law, huge volumes of low toxicity fluids are scheduled for controlled release into marine environments. In BP’s waste dispersion models for the Scotian Basin, the company anticipates that roughly 130,000 litres of synthetic drilling fluid will be discharged into the marine environment over the course of the project’s initial exploration phase, totalling just 120 days.

Alongside the anticipated synthetic-based mud discharge, BP’s contracted modellers estimated a “water-based mud” (WBM) release of more than 4 million litres. Comprised primarily of water, WBMs are significantly less toxic than synthetic muds, though they still contain oil-based synthetics and some chemical components. Commenting on the project in 2017, federal experts at Environment and Climate Change Canada suggested BP use only the less toxic WBMs as a drilling fluid instead of their more toxic, synthetic cousin, to mitigate against potential ecological harm. BP refused, saying that while relying on water-based mud exclusively was both economically and technically feasible, synthetic fluids offered drilling efficiency-related advantages that WBMs could not. The Canadian Government’s call for lower toxicity substances was snubbed outright by the operator.

To make matters worse, drill “cuttings”, comprised of rock retrieved through the drill-bit that’s been exposed to toxic mud during the extraction process, are released back into the water at a projected rate of 2.4 million litres for every 120-day project. In total, BP estimates a combined discharge of more than 6 million litres of drilling fluid (combining cuttings, SBMs, and WBMs) for the exploration of a single well in a single summer season.

And that’s just the exploration phase. If oil or natural gas is found, the extraction phase begins with some sites, like those at Newfoundland’s Hibernia and Terra Nova sites, producing fuel on a year-round basis for decades. The rate of legal discharge during the life cycle of an offshore project remains steady, if modest, releasing a perpetual stream of contaminated fluids into the ocean until the well runs dry.


Beyond these oil-based “muds”, and beyond any single incident, there is a more important story to tell about offshore development on Canada’s east coast.

These discharges and spills in the preliminary stages of BP’s Scotian Basin Exploration Drilling Project are a sliver of the total impact that offshore extraction exerts upon the marine environment. Today, each project is considered on a case-by-case basis. But the ocean is hyper-connected, ensuring no development project can exist (or be considered for approval) in a vacuum. The cumulative effects of hundreds of large scale, high-energy drilling initiatives across the Atlantic are not challenged in any meaningful way — not by provincial petroleum regulators, and not by the Canadian Environmental Assessment Agency.

Over time, the deleterious aspects of each project augment those before it, producing a patchwork of debilitated ecosystems and complicating any path to recovery we may plan once a project’s lifespan is complete.

Over the duration of any drilling initiative, by law, huge volumes of low toxicity fluids are scheduled for controlled release into marine environments.

In light of this knowledge, and amidst a host of concerns about cumulative effects laid out by government bodies, environmental non-profits, and First Nations, Canada’s assessment agency still approved BP’s Scotian Basin proposal in February of 2018. The final report addressed these effects as such: “The Agency has not identified any specific measures required to mitigate cumulative environmental effects beyond those identified to mitigate project effects on individual valued components.”

Today, investment in the Atlantic Canadian offshore continues at an alarming rate.

In Newfoundland and Labrador, after more than two decades of successful extraction, trillions of barrels of oil rendered, and all of the toxic discharge (controlled and uncontrolled), Premier Dwight Ball committed to doubling the province’s offshore oil output by 2030. In Halifax, Premier Stephen McNeil has continued to endorse offshore development in Nova Scotia. Some analyses suggest there could be as much as 3.5 trillion litres of natural gas and 1.3 trillion litres of oil in the Nova Scotian seabed, a resource potential that will tempt politicians for decades to come.

To be sure, nobody wants toxic substances to be discharged into the ocean — especially not major fossil fuel companies operating in an increasingly difficult and litigious climate to search for, extract, and ship oil and natural gas. But the volume of hazardous byproducts released during the offshore process drilling are immense. The ocean is vast, but BP is simply one of many companies, drilling many wells, in the North Atlantic.

Even if Canada’s Atlantic provinces had stronger regulators and better enforcement systems, the likelihood of disaster in one form or another is inevitable. Ultimately, we’re left with two choices: death-by-a-thousand-cuts, in which small-scale discharges are accepted at dozens of sites over decades, or irretractable damage caused by swift and major spills – in the end, it’s no choice at all. Continued spillage of any kind can devastate deepwater ecosystems. In today’s ocean of cumulative effects, at this scale of deep sea extraction, Atlantic Canada’s treasured marine environment will be forever changed.

Simon Ryder-Burbidge is a marine conservation officer with the Ecology Action Centre in Halifax, Nova Scotia.

If you liked this article, please subscribe or donate today to support our work.

A\J moderates comments to maintain a respectful and thoughtful discussion.
Comments may be considered for publication in the magazine.
  • The holidays are around the corner and it’s time to give some thought to how to green up your celebrations this yea… 11 hours 55 min ago
  • RT : Happy to have gotten the opportunity to interview Dr. (on-air medical expert & writer) & Dr. Thompson… 1 day 1 hour ago
  • Giving of yourself – and giving someone your open-mind to listen and to be edified – is one of the greatest gifts a… 1 day 11 hours ago