Bilge Dumping at Sea: What are SkyTruth and others doing about it?

With free public monitoring services and the help of watchdogs globally, bilge dumping can come to an end. SkyTruth’s new project Cerulean is one solution.

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

Throughout this multi-part series on global bilge dumping, we have revealed how SkyTruth has identified oily pollution from ocean-going vessels, the range of harmful effects to coastal communities and marine ecosystems, and the challenges in prosecuting ocean offenders. We now address the future. What’s next? 

Recall that bilge dumping occurs when vessels bypass treating their oily wastewater and discharge it directly into the ocean. When we started this series, we reported on SkyTruth’s 2019 ocean monitoring efforts in which we recorded 163 oily slicks around the world. So far this year we have detected 98 new slicks. Now that we better understand what is occurring at sea, we are working hard to share that information with citizen watchdogs and others, enabling them to take action such as alerting authorities and publicly exposing wrongdoing in their coastal waters. With sustained pressure, we hope polluters will be forced to act responsibly.

Using radar satellite imagery, SkyTruth can observe and measure oil pollution in the ocean. Making a conservative assumption about an oil slick’s thickness, we can estimate the volume of oil, an indicator of the severity of an incident. The legal limit for discharging oily wastewater under international law outlined by the International Convention for the Prevention of Pollution from Ships (MARPOL) is 15 ppm for most cargo vessels and tankers. Trained observers on aircraft can see oil at concentrations of 50 parts per million (ppm) and above. It’s possible that under favorable sea-state conditions, radar satellite imagery is capable of revealing oil at lower concentrations, so we’ll be able to spot more potential violations. In a resolution to MARPOL specifying visibility limits of oil discharges, the Marine Environment Protection Committee “urgently requests authorities to consider the principle that a visible trace of oil is one element of proof that the 15 ppm discharge standard of Annex I of the MARPOL Convention may have been violated.” Similarly, under the U.S. Clean Water Act, oil discharges that cause a visible sheen are encouraged to be reported and are classified as potentially harmful to public health or welfare. 

Using advanced remote sensing techniques, we often can determine a likely source of pollution, whether from a vessel, a natural oil seep, or energy infrastructure like pipelines, drill rigs and production platforms. This kind of information can help oil-spill response efforts: If they know the location and source of oil pollution, responders are better able to take action and reduce the impacts of the pollution. In addition, if the pollution is from a vessel, near-real-time monitoring can help authorities catch a perpetrator who might still be nearby, or take administrative action when that vessel comes into port. Prosecuting criminal offenses for environmental crime requires robust evidence connecting a culprit to the crime. Satellite imagery can help: It collects evidence remotely, potentially providing an efficient way to prosecute ocean offenders.

To demonstrate this potential, in late 2019 SkyTruth launched project Cerulean to automate the detection of oil slicks on the world’s oceans and identify likely sources. Cerulean applies a machine learning technique called Deep Learning (a type of Artificial Intelligence) to make it possible to analyze thousands of satellite images every day to detect slicks and sources. We compare these slicks with public Automatic Identification System (AIS) vessel tracking data in order to identify the likely sources of this pollution (you can read more about our process here).

Image 1. Sentinel-1 radar satellite image of suspected bilge slick (black streak) in the Java Sea on February 15, 2020. AIS signals are shown for two potential sources. The likely source vessel is circled in red, with its AIS track (red) closely matching the slick in space and time. The other nearby vessel’s broadcasts (white) did not match the time and location of the slick.

Satellite data such as that provided by Cerulean could potentially help prosecutors convict oil polluters if it is approved for use in court. Remote sensing evidence is a relatively new tool in court cases. It must be authenticated and checked for integrity regarding the collection and storage of the data to ensure its validity. In the United States, cases using satellite evidence have not been widely published since many decisions about whether evidence is admissible can be made orally or pretrial. Because of this, we do not have a good estimate of how frequently satellite imagery is accepted as evidence. However, we do know that if the remote sensing technology is not new or novel it is more easily admissible. When trying to prove a fact, an expert witness with specialized knowledge can explain the reliability of the technology used and the data presented. In describing the detection of an oily slick, for example, an expert might need to explain a variety of factors that are considered in the analysis of ocean imagery, including weather conditions such as rain and wind speed, atmospheric and oceanographic features, and differentiating a vessel from ocean infrastructure in order to demonstrate the admissibility of image-based evidence

Satellite imagery has been used as evidence of other environmental crimes such as deforestation and illegal fishing. However, it is uncommon for imagery alone to provide conclusive evidence, or to prove guilt beyond a reasonable doubt in prosecution for environmental crime. Satellite imagery has provided corroborating evidence that has led to prosecutions of pollution at sea. However, we have found no cases where it provided conclusive (dispositive) evidence, meaning it alone is usually not enough to link a crime to a perpetrator, or even prove that a crime occurred at all. Currently, eyewitness reporting is more often used as evidence for prosecution of bilge dumping. Whistleblowers and vessel inspectors have been a common catalyst for prosecution. For example, between 1993 and 2017, 76% of prosecuted cases under the U.S. Act to Prevent Pollution from Ships came from whistleblowers. Overall, there are no restrictions on satellite imagery’s power to serve as evidence in court as long as the technology has been proven valid and trustworthy.

Europe currently has an ocean monitoring service called the CleanSeaNet that has led to several prosecutions using satellite imagery in combination with on-ground evidence, in which fines were imposed. The European Union Directive 2009/123/EC specifies types of prosecution for ship-source pollution. However many courts still rarely prosecute. Often they require official inspection on site where the pollution occurred and on the vessel in order to connect the evidence to the crime, which can be challenging when collecting on-ground evidence is time sensitive. (Oil can disperse within 12 hours, and ships can easily be long gone by then.) Additionally, the European Maritime Safety Agency (EMSA) states “(r)esolution of cases can take many years, and in some countries privacy issues prevent the full details being disclosed publicly.” 

Image 2. Suspected bilge slick in the Gulf of Guinea on February 23, 2020. The red AIS signals closely follow the linear slick to the likely source vessel (circled in red). Another nearby vessel’s broadcasts (white AIS signals) were also analyzed; however, this vessel was moving nearly perpendicular to the slick and is not a likely source.

But law enforcement agencies and citizen-activists aren’t the only stakeholders concerned about clean oceans. Companies have market-based incentives to be recognized as sustainable and socially responsible businesses, and they are liable to their stakeholders to uphold promises of corporate social responsibility. While the shipping industry produces ocean oil pollution, it is also the most energy efficient method for transporting goods. Such a large and fast-growing industry requires effective environmental regulation and enforcement. 

The International Maritime Organization’s (IMO) theme for 2020 provides a unique opportunity for the shipping industry to clean up its act. The theme is “Sustainable shipping for a sustainable planet.”  For example, part of this includes the IMO’s 2020 sulphur cap on ships’ fuel oil. In transitioning to lower sulphur fuel, some shipping companies must adjust their current operations and infrastructure, which requires financing. By choosing cleaner ships that meet current and future environmental standards, investors, banks and other stakeholders consider Environmental, Social, and Governance (ESG) criteria. ESG concerns have led to efforts such as the Sustainable Shipping Initiative (SSI), an international partnership that promotes sustainability between its members, from ship owners to insurers to NGOs. SSI’s “Save As You Sail” program partners ship owners with financial providers in order to update vessels with more efficient emission-reducing technology and save on fuel costs. 

Additionally, vessel companies can voluntarily use grading initiatives such as the Swedish Clean Shipping Index (CSI) to hold themselves accountable. CSI scores a vessel company and its operations from its supply chain to emissions to operational discharges, allowing investors, clean tech providers, and other stakeholders, such as freight forwarders, to partner with responsible vessels who can be trusted to comply with international standards. A similar program exists in North America called Green Marine. The Environmental Ship Index (ESI) is an international scoring option that provides vessel-specific scoring and offers incentives such as discounts on port dues and bonuses to clean ships. Its index currently evaluates over 7,000 ships globally. To help support responsible ships and shipping practices, investment frameworks such as The Poseidon Principles provide banks around the world with principles that align ship financing with climate interests. Several large European banks such as the European Investment Bank (EIB) are committed to providing green investments through Blue Economy Finance Principles. These principles were created by the EIB to uphold the United Nations Environment Programme’s Sustainable Development Goal “Life below water.” In 2018, two banks, EIB and ING, agreed to provide 300 million euros of financing to support green shipping in Europe. These initiatives provide evidence that sustainability and a blue economy aren’t mutually exclusive. 

Cerulean aims to support international clean sea initiatives as well as stakeholder interests by providing a platform for stakeholders to directly monitor oily discharges from vessels. Companies and coalitions like those listed above can use Cerulean to help ensure a greener supply chain. Scoring indexes can use Cerulean to make sure vessels hold true to their ratings, allowing investors and insurers to be more confident in their partnerships. Widespread transparency of activity in the oceans encourages vessel operators, owners, and crew to operate responsibly in order to continue to receive support from their clients and other stakeholders, as well as to avoid criminal penalties. 

Image 3. These bright lines, compiled from dozens of radar satellite images, reveal heavy vessel traffic through the Strait of Malacca, one of the world’s busiest shipping lanes, over the course of several months in 2019.

Our conversation with a resort director in Southeast Asia suggests Cerulean will support citizen activists as well. This resort director (first introduced in the second blog post in this series) reached out to SkyTruth to share some of his experiences with bilge dumping. He has regularly found oil and tar washing ashore on beaches near Singapore and the Strait of Malacca for several years. He believes that part of the reason ship operators act irresponsibly is that they don’t really understand that they can be monitored, and don’t realize that their AIS broadcasts can be collected by the public. As an environmental activist whose livelihood depends on a clean coast, he would like to make vessel operators more aware of the transparency of their behavior and is interested in doing more personal monitoring of the sea surrounding his property. He believes Cerulean can help him, stating  “(i)t is super compelling to pair satellite data with AIS.” Knowledge of potential oil slicks nearby, even at night, allows citizens to prepare for when oil hits the land and can alleviate some of the clean-up. “It would be useful to know if a slick is coming,” he said. “We could get people organized to stop it. If we had a warning — even 30 minutes, it would give us enough time to make a difference.”

While the first version of Cerulean won’t provide continuous monitoring of the ocean (because the satellites now in orbit can only cover a portion of the earth every day), it would allow insight into ocean pollution every several days and will build a one-of-a-kind record of incidents over time. One key objective of Cerulean is to establish a scalable pipeline that can process more and more images as new satellite constellations are launched and cover our oceans more continuously. 

Cerulean is currently under development, and we hope to have an operational product by 2021. Once up and running, Cerulean will be free and open to the public, providing a user-friendly interface that allows anyone, without any technical expertise, to monitor their areas of interest for oily slicks. Users can receive near real-time alerts for oil detected in their area of interest along with insights into who might be responsible for the pollution. Cerulean will identify features such as a slick’s location, date, time, and length, in addition to specific vessel characteristics such as a vessel’s ID number, destination, owner, operator, and flag country. We hope Cerulean will provide more insight into hotspots — where bilge dumping is particularly common — as well as track repeat offenders to enable more robust prosecutions. We anticipate Cerulean will be a useful tool for fleet owners, shipping companies, and international merchandise retailers that choose to be environmentally responsible: they’ll be able to use Cerulean to track the performance of their fleet and incentivize operators and crew to stay in compliance with ocean law. Additionally, law enforcement can use these near real-time alerts to catch perpetrators in port and in coastal waters. Finally, we hope it will be a tool that empowers citizen watchdogs, nongovernmental organizations (NGOs) and journalists  to keep an eye on what’s happening at sea, report wrongdoings, and rachet up pressure on governments and businesses to do a better job protecting our ocean. 

In the meantime, SkyTruth analysts will continue to monitor hotspots in the ocean and share our results on this blog. By continuing to report on pollution across the world, innovate user-friendly platforms, and spread awareness, we are working to stop oil pollution at sea and protect the world’s marine ecosystems and the coastal communities that depend on them. 

Ten years ago SkyTruth Revealed the Truth about the BP Oil Spill

SkyTruth video highlights our work fighting oil pollution, then and now.

Ten years ago last week, BP’s Deepwater Horizon platform in the Gulf of Mexico exploded, killing 11 men and setting off the worst environmental disaster in U.S. history. SkyTruth was there; not in person but remotely; using satellite imagery to track the spill from space. Working with oceanographer Ian MacDonald, we estimated that the amount of oil gushing from the broken wellhead was more than an order of magnitude larger than the estimates provided by BP and the U.S. Coast Guard. By making our independent analyses available to the public, we generated national and international media attention, and created pressure on the federal government to create its own scientific task force to determine the true size of the spill. Their conclusion, months later, was even larger than our estimates, and set the stage for the billions of dollars that BP eventually paid to help restore Gulf ecosystems and economies.

Watch our four-minute video to learn more about the disaster, and what SkyTruth is doing now to stop oil pollution at sea.

Thanks to Thad Reid for helping us with this production.

Bilge Dumping in Southeast Asia Continues in 2020

Southeast Asia appears to be a hotspot for bilge dumping.

SkyTruth continues to find frequent instances of apparent bilge dumping in the waters of Southeast Asia. Bilge dumping occurs when cargo vessels and tankers illegally discharge oily wastewater directly into the ocean. Vessel operators might do this to avoid the costs of treating their polluted wastewater, as required under international law (read more about that here).

On March 23, Sentinel-1 imagery captured three likely bilge slicks off the coast of Madura Island in Indonesia. The yellow circles in the image below highlight the length and variety of the slicks. In this image, two of the three bilge slicks reach a length of almost 90 kilometers (almost 56 miles). Multiple long bilge slicks in such close proximity to each other show an alarming trend for this region.

 

Image 1. Three suspected bilge slicks of varying length surround Madura Island in Indonesia.

On March 15, Sentinel-1 imagery captured another potential bilge slick about 30 kilometers long off the coast of Malaysia in the Java Sea. Using Automatic Identification System (AIS) broadcasts from the vessel, SkyTruth identified the likely source of this slick as the Indonesian vessel known as the ARIN 8. 

 

Image 2. A vessel spotted off the coast of Malaysia leaving a black trail in its path: an oily slick indicating a possible instance of bilge dumping.

SkyTruth frequently documented bilge slicks in Southeast Asian waters throughout 2019 suggesting that this region is a hotspot for dumping, and in 2020 we’ve spotted oily slicks indicating more than 25 potential bilge dumping incidents in the  region. These slicks ranged from 20 to 100 kilometers (12 to 62 miles) in length. SkyTruth will continue to monitor this high traffic area to help bring attention to the issues in this region. 

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.

 

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.