Bilge Dumping at Sea: How can this be happening?

Despite large penalties for breaking the law, bilge dumping continues to occur. Infrequent prosecution, combined with incentives to dump oily waste instead of treating it, means some polluters take their chances.

This is the third entry in a multi-part series revealing the significance of bilge dumping globally. You can read parts one and two on SkyTruth’s blog. 

Today, ninety percent of international trade relies on global shipping. From commercial to passenger vessels the world’s global fleet exceeds 95,402 ships plus around 2.8 million fishing vessels. With all this ocean traffic occurring every day, SkyTruth has been monitoring the oceans for bilge dumping; the illegal discharge of oily wastewater at sea. In this post, we explore regulations governing bilge dumping and consider why this practice is so widespread, despite these regulations.

International regulations exist to ensure shipping practices are environmentally sound. The International Maritime Organization (IMO) is considered the global regulator of shipping; its regulations apply to 99% of the world’s merchant tonnage. Its convention —  the International Convention for the Prevention of Pollution from Ships (known more commonly as MARPOL) — has six annexes regulating several types of vessel pollution; everything from dangerous cargo, garbage, and noxious emissions, with one specific annex dedicated entirely to the treatment of oily waste mixtures, including oily bilge, and standards for operational or accidental discharges. Currently, vessels are allowed to return dirty water to the ocean, but are limited to discharge oil concentrations of no more than 15 parts per million (ppm), a limit that requires the use of machines called oil-water separators to reach. This is a strict requirement in the annex. Large vessels over 10,000 gross tonnage are required to install alarms and automatic stopping devices if the wastewater exceeds 15 ppm.  When vessels discharge untreated or insufficiently treated bilge, they circumvent this crucial step in the disposal process. 

With options to properly treat oily wastewater, and costly deterrents for breaking the law, it can seem confounding that vessels continue to deliberately pollute the ocean. Penalties for breaking the law include criminal felonies such as obstruction of justice, fines up to $40 million, probation of the shipping company and its operating vessels, as well as prison sentences for those directly responsible. Fines can support environmental compliance programs as well as community service and remediation funds. Under the U.S. Act to Prevent Pollution from Ships (APPS) up to 50% of the value of these fines provide compensation for whistleblowers involved in the prosecution. When whistleblowers report wrongdoings they are risking their employment as well as potential retaliation such as abuse. Appropriate compensation is an important incentive for whistleblowers to continue to take these risks, especially since whistleblowers are responsible for a a large number of successful convictions. However, compensation can be uncertain since it depends on how useful a court deems the information whistleblowers provide. It is questionable whether incentives to whistleblowers are strong enough, especially considering many cases aren’t heard or fail to result in prosecution. In 2016, 23 corporations were convicted in the United States; however, Marine Defenders, an educational program to reduce oil pollution in U.S. coastal waters, predicts that 5,000-7,500 vessels discharge untreated bilge around the world annually.  

Vessel operators are required to maintain an oil logbook that contains all cleaning and disposal events — whether intentional or accidental, legal or illegal. When accusations of bilge dumping appear in court, they often uncover false logbooks or inaccurate records of discharged pollutants at sea. This can reveal that the vessel is using bypass equipment or tampering with the oil-water separator to avoid appropriate treatment. Logbooks can be verified through vessel inspections, or sometimes with the help of whistleblowers. It is often these false logbooks that lead to large fines. Under the APPS, vessel owners face the largest fines. Additional fines and sentences can also be given to individuals directly responsible for the crime — usually the vessel operators or engineers

 

Image 1. The Marshall Island-flagged Ridgebury Alexandra Z. The Cyprus shipping company was penalized with a $2 million fine. Photo courtesy of Vessel Finder

But some vessels might not see the value in complying with MARPOL requirements if the savings of simply dumping oily wastewater into the ocean outweigh the potential risks. It is costly for vessels to treat their wastewater and requires they either invest upfront in an on-board treatment system or they pay for treatment at a port facility. Both of these options can cost tens of thousands of dollars a year depending on the amount of travel and fuel used. Operators, officers, and engineers have all been found to bypass expensive treatment or avoid operating costs, allowing vessels to gain a competitive advantage. Officers can receive bonuses if environmental compliance budgets are maintained. Some players in the shipping industry have been reported to treat crew members poorly, and crew members can be threatened with job loss or lost wages if they fail to follow orders. 

In some cases, vessels without oil-water separator equipment that need to empty their hull of oily waste might choose to avoid the extra travel needed to reach a port facility with the appropriate equipment, and instead dump the wastewater into the sea on route. However, there is no shortage of port reception facilities. IMO reports 3,253 facilities to treat oily bilge water in over 80 member states in its Global Integrated Shipping Information System, and the majority of these port facilities are conveniently located along common shipping routes. Some of these vessel operators might assume they have a low probability of being caught, and perhaps are unaware of how closely they can be monitored by Global Positioning System (GPS), satellites, and nearby aircraft or other vessels. Operators who fear being caught sometimes illegally alter or turn off their Automatic Identification System (AIS) and “go dark” at sea. AIS is a radio frequency broadcast equipped with GPS that is mandatory on almost all large oceangoing vessels, to help promote safety at sea. Ships can communicate through AIS and avoid collisions in high traffic situations.

Image 2. Major shipping lanes revealed by a year’s worth of AIS broadcasts from non-fishing vessels. Map courtesy of Global Fishing Watch.

Another incentive for illegal bilge discharge: an overwhelming number of illegal ocean dumpers go unpenalized for their crimes in many different countries. Vessels can control the level of enforcement they face by registering to sail under a flag that is different from the country in which the vessel is owned. For example, in 2015 a German-owned motor vessel named City of Tokyo, operating under the flag of Liberia, was caught bilge dumping off the Alaskan coast. Often this means a vessel from a developed state is using the flag of a developing state; Panama, Liberia and Marshall Islands currently flag the world’s largest fleets. More than 70 percent of the world’s merchant vessels are registered under a different flag state. By choosing a flag of convenience, vessel operators, without a genuine link to their country of ownership, can find advantageous loopholes depending on a flag state’s national laws. They can shop for lower registration fees and taxes and can choose a registry that allows them to remain anonymous. They can also recruit a foreign workforce at lower labor costs. Essentially, some developing states prioritize economic development over environmental enforcement

The United Nations Convention on the Law of the Sea (UNCLOS) is the legal framework states use to adopt international laws for the world’s oceans. It differentiates rights in territorial seas near each state’s coastlines, and non-territorial or high seas. Since individual states have jurisdiction to adopt (“in conformity with generally accepted international regulations”) and enforce their own national laws, prosecution for environmental harm such as bilge dumping varies in leniency. UNCLOS specifies that flag states have exclusive jurisdiction over their ships on the high seas. Exclusive jurisdiction means vessels abide by flag state laws and are subject to flag state prosecution. Additionally, flag states issue vessels their compliance certifications by approving the vessel’s equipment and crew. These certifications can be used by vessels when passing through other states’ territorial waters, making it difficult for port or coastal states to pursue noncompliance of other flag state vessels within their territorial waters. It is only in territorial waters and under good reason that a foreign state can make a hot pursuit on vessels neglecting the law. 

 It can seem confounding why enforcement is so infrequent globally given that, under UNCLOS, each flag state should have at least minimal legislation. SkyTruth spoke with John Kostyack, executive director of the National Whistleblower Center to answer this question. Kostyack told us “The concept behind treaties like MARPOL is that domestic legislation then implements them, but most countries have either not passed legislation, or they have legislation that is not enforced consistently.” Kostyack notes that fines are imposed in some countries, including the US, but the level of penalties are nowhere near sufficient, stating “(d)umping oily waste illegally is seen by these companies as a risk worth taking because they don’t see a significant threat of prosecution. Even when penalties are imposed they are not steep enough to change behavior. This is a recipe for continued pollution.” Ultimately, Kostyack feels the primary reason vessels are bilge dumping is because it is cheaper to occasionally pay modest penalties than to pay to treat their own waste. 

SkyTruth will continue to search the world’s oceans for illegal bilge dumping. We are currently working to automate this process to cover more areas in near real-time. We hope that by revealing this otherwise often hidden practice, we can arm whistleblowers and others with useful information to prosecute these crimes more frequently, and create greater incentives for vessel owners and operators to comply with international law.

 

What’s a Mathematician Doing at SkyTruth?

Alice Foster discovered her love for geology at Brown University, and meandered onto SkyTruth’s path.

My name is Alice Foster, and I started as an intern at SkyTruth this past January. But my journey to SkyTruth was a bit unexpected. I am currently studying applied mathematics at Brown University. And until recently, I was somewhat unenthusiastic about science, although I was interested in conservation issues.

Then, in search of an introductory environmental studies class at my first academic fair, I ended up talking to a professor at the Department of Earth, Environmental, and Planetary Sciences table. She convinced me to try out her class, which she said offered a good foundation for understanding environmental issues. In the opening lecture, I was a bit disappointed to learn that the class was about geology; lacking any understanding of the subject beyond an earthquake project in seventh grade, I associated the word with something vaguely boring and irrelevant. But after a few minutes, I was hooked. I found it beautiful to understand how mountain ranges and canyons and plains come into being, and to try to wrap my head around the massive time scales on which geological processes take place. Learning about crystal deformation at a molecular level was fascinating because it could explain how an entire glacier moves. Everything seemed to fit together. Over the course of the semester we applied physics and chemistry, satellite and seismic imagery, and logic to solve Earth’s riddles. 

One of my favorite topics covered in that class was meandering rivers, a concept I identified with. A meander forms a curve in a river: fast-moving water wears away at the outer bank, while sediment transported by slower-moving water amasses at the inner edge, creating a point bar. This process of erosion and deposition makes the bends bendier and the river wander. 

If you look at outcrops on the side of a road, you might spot evidence of ancient meandering rivers. A fast-moving river can transport and deposit large pebbles in its channel. When the water changes course, the former channel becomes part of the river’s floodplain. At times, the river overwhelms its banks and leaves behind sand and clay to overlay the old layer. Some years later, the channel might shift again and deposit larger grains on top of the fine particles. In the rock record, these deposits can appear as beds of shale interspersed with conglomerates.

Alice camping with friends. Photo by Ailita Eddy.

The summer after I took this geology class, I encountered a magnificent meandering river near a farm I worked at in Iowa. Tall trees with lush foliage grew on one bank; a cow pasture bordered the other. I liked to walk down the road to a bridge overlooking the river. I imagined it all playing out: water flowing around the outer edge and loosening soil from the steep bank, bits of rock bouncing chaotically along the riverbed, and the inner bank growing thick with silt. In millions of years, the vestiges of the river might lie deep beneath the ground, compacted, cemented, and turned to stone. 

Since then, my interest in geology and climate science, combined with my love for mathematics, has informed my meandering career exploration. This semester, I decided to take a break from school and homework and experience new things. I wanted to intern at SkyTruth because SkyTruth’s work combines many of my greatest passions, and because I felt excited about contributing to work that could benefit others. It is amazing to see up close how SkyTruth uses geospatial technology to solve tangible problems. I get to think about math and geology while engaging with immediate conservation issues around the world. 

Right now I am working on monitoring bilge dumping in oceans around the Arabian Peninsula, Africa, and Brazil. I am also working with SkyTruth staff to digitize natural gas well pads for a machine learning model. This model will allow SkyTruth to automatically identify well pads in Alaska and Patagonia.

As an intern I have had the chance to learn how to create maps in QGIS and how to program in Google Earth Engine. QGIS is a geographic information system application that can be used to analyze and visualize geospatial data such as satellite imagery or a ship’s track across the ocean. I have also gotten to reflect on what I might want my career to look like. I love getting to be part of a welcoming, supportive, super knowledgeable, all-around wonderful group of people pursuing new projects and ideas. Though I am unsure of my path, this is the kind of environment I will look for as I embark on my career.

Alice made this on a letterpress printer using a linoleum carving block and metal type. “Wild Geese” is one of her favorite poems. She wanted to create an image having to do with the refuge one can find in the natural world. Credit: Alice Foster

Bilge Dumping at Sea: Why should I care?

Scientific research on the impact of oil pollution on marine life and coastal communities, combined with evidence of frequent bilge dumping, suggests oily bilge could be harming marine ecosystems and coastal economies.

This is the second entry in a multi-part series revealing the significance of bilge dumping globally.

Last year SkyTruth reported 163 accounts of likely bilge dumping across the world, from Brazil, to the Mediterranean, to Southeast Asia and elsewhere. As we described in our recent post,  bilge dumping is the illegal release of untreated oily wastewater from a vessel’s lower hull. This wastewater, or bilge, appears as an oil slick in the ocean, which eventually disperses and can migrate to vulnerable coastlines.  

Because it happens out at sea, bilge dumping traditionally has been an enigmatic source of pollution and challenging to consistently monitor. Although SkyTruth is working to change that, so far the negative effects of bilge dumping are sparsely documented. To explore the potential impacts of frequent bilge dumping worldwide, we can start by considering the contaminants oily bilge waste contains. Oily bilge waste water is the byproduct of operating ocean-going vessels and, according to the Environmental Protection Agency, contains contaminants such as lubricants, grease, and cleaning fluids, as well as harmful or toxic metals such as arsenic, cadmium, chromium, lead, and selenium, some of which are known or probable carcinogens. Other harmful substances in bilge can include organic chemicals such as benzene, chloroform, hexachlorocyclohexane isomers, and naphthalene

The size of tankers and container vessels that dump their waste can help us understand the amount of pollution they are emitting. Commercial marine vessels are some of the largest machines in the world, with some measuring 131 meters (143 yards) in length; comparable to the size of a small skyscraper. The engines in these vessels can be as large as three buses and have up to 333 times more horsepower than the engine of a midsize car. Their large size makes cargo vessels very efficient for transporting goods; but if the waste from these massive engines routinely ends up in the oceans, their environmental impact can be substantial. Even two decades ago, researchers reported that ocean-going vessels generated millions of tons of waste annually. A 2003 report by the nonprofit conservation group Oceana estimated that in European waters alone “illegal dumping and routine operations of vessels account for between 666,000 and over 2.5 million tons of hydrocarbons of marine pollution per year.” That amount is up to 70 times greater than the Exxon Valdez oil spill and is likely even greater today. Over a 20 year span from 1992 to 2012, the amount of ocean-going traffic has grown by 300%, increasing the likelihood of even more vessel pollution. 

A large research collaboration published by The National Academies Press (2003) found that between 1990 and 1999 vessels (in contrast to pipelines or facilities) in US waters produced the largest oil spills. Additionally, this research reports that 12 percent of the total petroleum hydrocarbons found worldwide in the oceans were from “accidental spills and operational discharges of cargo oil occurring during transportation of petroleum products.” This accounted for 160,000 tonnes of oil annually; the equivalent of four Exxon Valdez oil spills every year. 

Exxon Valdez oil spill [photo courtesy ARLIS, Alaska Resources Library & information Services]

Exxon Valdez oil spill [photo courtesy ARLIS, Alaska Resources Library & information Services]

The negative effects of bilge dumping can be seen in the United Arab Emirates. In 2017, one of the emirates, Fujairah experienced three oil spills in just two months. Locals reported that this contributed to a significant decrease in local hotel bookings and left dead fish and black oil on the shores. Last year, nine Brazilian states and 132 beaches were impacted by multiple mysterious incidents of oil washing up onshore. The cause of these incidents still has not been determined, but one possibility is a series of bilge dumping incidents. The impact occurred in multiple biodiverse tourism areas, specifically in Brazil’s oldest national park

SkyTruth also continues to find oil offshore Nigeria, in the Gulf of Guinea. And while this oil is mostly a consequence of energy infrastructure, we suspect this oil stems from bilge dumping as well. Nigeria’s Niger Delta, which drains into the Gulf of Guinea, experiences periodic water contamination from heavy metals due to extensive energy development, so much so that the delta has been called the “oil rivers.” Over a 38 year timespan, 12,000 oil spills were reported in the delta. Communities often use this water untreated for cooking or drinking as well as for local agriculture and fish farming. 

Heavy oil has been sullying the beaches of northeastern Brazil since early September. The cause remains elusive. [Photo courtesy tvBrasil via Creative Commons license]

Recently, an environmental activist and resort director contacted SkyTruth after repeatedly discovering remnants of oil and tar washing up on beaches near Singapore and the Strait of Malacca, one of the world’s busiest shipping lanes. This local activist continues to report regular incidents that they believe may be the result of bilge dumping. 

When oil washes up onshore, our Southeast Asian source states that it sometimes can be small and relatively easy to clean up, but at times, when it’s a bad spill, “it can be barrels full of it, or it can be thick tar balls, sometimes five to six inches across — so large that they look like they came out of a pipe,” he told us. The oil releases a “distinct petroleum smell” and “if it gets in amongst the rocks it can take months to clean out,” he told us. “If it washes up on a beach at high tide, it melts in the sun and is terribly messy to clean up.” Most incidents happen during the northeast monsoon season when the region gets stronger winds; however, outside of this season oil still lingers. “I can almost always walk down a beach and find some,” he told us. 

Video of oil globs from suspected bilge dumping washing up on a beach in Southeast Asia in February 2020. Video by anonymous.

Studies from oil spills suggest that oil at sea disperses over a period of days to weeks, and some of this oil can wash up on coastlines, potentially harming ecosystems and soiling beaches. Vessel bilge dumping incidents typically receive less attention than large oil spills: they are much smaller-scale events, but occur more frequently and potentially can have a significant cumulative effect. The substantial scientific literature analyzing the effects of large-scale historical oil spills — most notably BP’s Deepwater Horizon and the Exxon Valdez — could help shed light on the potential impacts of bilge dumping.

The impact of oil on a community’s natural environment can be very prominent, and it varies. When a slick disintegrates, its components can weather into dense tar balls which pile up on shores, as well form a messy sludge coined chocolate mousse. Well-protected clean-up teams are needed to carefully remove oil from coastal areas.

One unsettling outcome from oil in the water is its effects on marine life — from acute to progressive diseases. After the Deepwater Horizon oil spill, dolphin deaths from lung and adrenal lesions increased, and reproduction decreased, which scientists believe could be linked to exposure to oil. In addition, a multi-state natural resource damage assessment estimates that as many as 102,000 birds were killed or harmed during the Deepwater Horizon spill. Mangroves and coral reefs in Brazil, Panama and Singapore have been harmed by oil in the water. Human health can also be affected. One survey from an oil spill in Pakistan in 2003 found those who lived near the coastline experienced eye, skin, and respiratory health symptoms, asfumes and a mist of oil in the air.” Far worse, years after an oil spill offshore Spain, some cleanup workers of the spill showed signs of genetic mutations in their blood, potential catalysts for more serious disease. 

Lastly, oil spills have triggered social and psychological distress. After the Deepwater Horizon disaster, some impacted individuals were found to have high oil related stress and PTSD related symptoms. This discomfort led to lengthy lawsuits and ongoing political protests by citizens who felt that the energy company responsible, BP, was not taking full responsibility. 

Bilge dumping is unlikely to trigger such large-scale reactions. However, based on what SkyTruth has documented over the past year, we believe that bilge dumping could be the stealthy, less recognized cousin to large oil spills, that cumulatively leads to large amounts of oil in ocean waters and coastlines. Perpetrators often evade prosecution and accountability, leaving communities to bear the impacts and costs. 

Although scientific research on bilge dumping per se is limited, harmful impacts of oil pollution on marine life, human health, and coastal communities are well documented. Given the dozens of likely bilge dumping incidents SkyTruth has revealed over the past year, and the concerns expressed to us by coastal residents, we believe bilge dumping could be a sleeper source of oil pollution in the sea. It’s time to do something about it. 

 

New Intern Matthew Ibarra Shifts from Aerospace Engineering to Protecting the Planet from Space

Matthew thought he wanted to be an aerospace engineer when he started college. Then he learned more about environmental damage to the planet.

Hello There!

My name is Matthew Ibarra and I am a new intern at SkyTruth. I am currently a student attending West Virginia University (WVU). Originally I came to WVU to study mechanical and aerospace engineering. I have always been passionate about math and science and so naturally I believed engineering would be a perfect fit for me. I was a part of my robotics team in high school and I believed this would be something I could do forever. 

However, as my time at WVU went on I became much less interested in engineering and I decided that I wanted to study something else. Through my engineering classes I inadvertently learned more about energy and from there about renewable energy sources. I developed a passion for renewables and I decided I wanted to shift my focus of study and work on environmental challenges. I have always felt there is a lot more bad news than good news in the world and I kept hearing about problems such as massive deforestation in the Amazon, pollution of the planet and the oceans — and those were just the tip of the melting iceberg. I wanted to do something that would leave a lasting impact. All of these factors pushed me to change my major to Environmental and Energy Resource Management. And it was the best decision I have ever made. 

Matthew played saxaphone for the WVU marching band and currently plays clarinet in the WVU Concert Band and saxophone in the WVU pep band. Photo by Roger Sealey.

My best friend Amanda’s mother Teri works at SkyTruth as our office administrator, which was very serendipitous for me. Amanda told me about SkyTruth and I was excited to learn how SkyTruth gathers environmental data and conducts research using satellite imagery. I was intrigued because it seemed like SkyTruth worked in all the areas I was passionate about: the environment, technology, and research. I looked into some of SkyTruth’s current and past projects and the ones that excited me the most include FrackFinder, which helps keep track of the environmental impacts of fracking for natural gas. I was also excited about SkyTruth’s interactive maps that help track the removal of mountaintops from coal mining. SkyTruth works on many other projects that I knew that I wanted to be a part of as well. An internship at SkyTruth was the perfect way for me to not only help work on projects I cared about, but also to learn more about what I am interested in.

As an intern I am currently working to monitor the South East Asia region for bilge dumps. Bilge dumps are illegal practices by vessels that attempt to bypass pollution control and dump their oily ballast and waste water at sea. I am collecting useful data that will contribute to a machine learning program that can automatically detect bilge dumps from satellite images around the world. I am also working to update FrackFinder to include data from 2016 and create an interactive map that can easily display information such as natural gas well pad locations in West Virginia, and when they were drilled, to show how natural gas fracking has impacted West Virginia over time.

I am passionate about sustainability and hope to make this central to my career. Sustainability is the notion of living your life in such a way that you leave resources for the people who come after you. After my time here at SkyTruth I hope to go into government work. I would like to work for the Department of Energy in the Office of Energy Efficiency and Renewable Energy. Fossil fuels will eventually run out and a transition to renewables will help current climate and environmental issues. I feel that it is important to find solutions now and transition our power needs to something that is more sustainable while we are still able to do so. 

Matthew admires Blackwater Canyon in West Virginia. Photo by Matthew Ibarra.

I believe SkyTruth is important in achieving my goals because I am gaining valuable skills and knowledge that I know will help me in the future. I love working with Geographic Information System programs (GIS). GIS is essentially using computers to analyze physical features of the Earth such as measuring forest density or tracking changing temperatures; it has almost endless applications.  I am learning to work with Google Earth Engine which is essentially a super powerful and intuitive way to work in GIS. Earth Engine requires me to be able to code in the programming language JavaScript and so I’m learning that skill as well. These are skills that will be forever relevant in the future and I am excited to deepen my understanding of them.

When I started college five years ago I never thought that I would end up where I am today. I spent so many sleepless nights trying to finish my physics homework and study my chemistry notes. I never thought that I would want to give all that up to work in something completely different, but I am thankful I did. I am eager to be learning something new every day at SkyTruth and I am thankful to everyone who helped me get to where I am today. I am excited to continue my internship here and keep learning more about what’s important to me.

Matthew is a hockey fan and celebrated the DC Capitals’ Stanley Cup victory in 2018. Photo by Photos Beyond DC.

 

 

A Systematic Search for Bilge Dumping at Sea: 2019 in Review

What can a year’s worth of bilge dumping data tell us?

This is the first entry in a multi-part series revealing the significance of bilge dumping globally. 

Out of sight, beyond the horizon, lies a world of activity taking place in the sea. The ocean encompasses over 70% of the globe, yet most of us only see its edges from the coasts. We’ve built many of humanity’s largest and most advanced societies along coastal regions, yet because the ocean is so remote, much of what happens there remains mysterious.  

You might think of crime at sea as violence (piracy), abuse of natural resources (illegal fishing), or pollution (oil spills). However, at SkyTruth, we’ve recently focused on combating another very troubling action on the water: a serious crime known as bilge dumping. While not as well known as pollution like the Great Pacific Garbage Patch, bilge dumping is a phenomenon that should not be overlooked, and yet it often is. 

Bilge dumping occurs when a vessel illegally releases untreated, oily wastewater into the ocean. This wastewater, known as bilge, collects in the ship’s lower hull and needs to be emptied regularly. Since the 1970’s an international law known as MARPOL has required that bilge water be treated to remove the oil before the bilge can be legally discharged into the sea. When a vessel circumvents treatment and dumps directly into the ocean, its wastewater creates an oily slick on the water. Radar satellite imagery captures these distinctive slicks — dark and opaque — because oil smoothes the surface of the water. This dense oily slick lingers in the water until it’s broken apart by wind and wave action, dispersing toxins and globs of oil that can harm coastal communities and marine ecosystems. Vessel operators probably commit this crime as an act of convenience: to save money or time cleaning up after themselves, imposing on others the negative consequences.

SkyTruth has observed likely bilge dumping incidents around the globe many times since 2007. But in 2019, we started seeking out these incidents more systematically. We focused our daily monitoring efforts on some of the world’s major shipping lanes and on areas where we’ve found problems in the past, cataloguing every incident of bilge dumping we found through imagery. Our intent was to better understand the scope of this recurrent problem. We noted that when we went to look for oily slicks, we always found more! Unfortunately, we began to expect to see them; they were occurring somewhere within the areas we monitored almost every day. And our monitoring only covered a small part of the ocean. 

In total, between January and December 2019, we found 163 slicks averaging 56 kilometers (almost 35 miles) in length. We almost always found bilge dumps using Sentinel-1 imagery:  high-resolution C-band Synthetic Aperture Radar satellite data made available by the European Space Agency. Although this imagery is sparse over the open ocean (see our blog post showing the coverage provided by these and other imaging satellites), it is collected regularly in coastal areas and provided coverage of several areas we considered likely to experience bilge dumping. Figure 1 documents each bilge dump incident we discovered, identified as red dots (note that because our monitoring was not covering the entire ocean, the lack of red dots in many areas on this map doesn’t necessarily mean those areas are free from bilge dumping).

 

Figure 1: Likely bilge dumping events identified by SkyTruth in 2019.

Our work suggests that bilge dumping isn’t sporadic; we repeatedly detected this illegal behavior in shipping lanes across the world, usually surrounding areas with significant energy development or active commercial ports, and often in areas with a “chokepoint” of marine traffic congestion. Bilge dumping was commonly seen in Southeast Asia, the Persian Gulf, and the Gulf of Guinea. Less frequently, but notably, we discovered it off the coast of Brazil, in the Mediterranean Sea, and in the Gulf of Mexico. In some cases, we have been able to identify the polluters, by correlating Automatic Identification System broadcasts (used to prevent collisions) from ships, with the time and location of oily slicks. 

In 2020, SkyTruth is working towards automating this process so we can routinely monitor much more of the ocean. We plan to use machine learning techniques to scan available satellite imagery daily, with the hopes of identifying these slicks automatically. Near real-time detection will allow authorities and the public to respond as soon as they receive notice of the slick, meaning more perpetrators (who might still be nearby, or headed into port) can be caught, and timely actions can be taken to mitigate potential environmental harm.

Figure 2. Likely bilge dump incidents identified by SkyTruth in 2019 by region.

The next segments of this series will explore bilge dumping in more depth, includingWhy should you care?” “How can this be happening?” and “What can be done about it?” We work as  space detectives —  investigating meticulously from above, revealing as much as we can down to the most pressing and actionable details. As we increase monitoring, automate the detection of offshore pollution with the use of machine learning, and raise public awareness, polluters will learn that they are being watched. We believe that more transparency leads to better behavior, better management, and better outcomes for Planet Earth. At SkyTruth, we are working to stop this illegal pollution by giving it the scrutiny it deserves. 

 

Updated 5/11/20