NASA Earth Observatory image modified by SkyTruth
Our model highlights possible oil slicks and sources, which users can verify in the map interface. Learn how to use Cerulean through our tutorial videos and FAQ. Distinguish between true oil slicks and their lookalikes using our slick identification guide.
To improve accuracy and usability, we released Cerulean v1.0 in October 2024, featuring enhanced slick detection and a streamlined interface. SkyTruth initially launched a beta version in November 2023. Read more about the methods and models behind the technology. For API data access, see our Cerulean API Developer Guide.
With user feedback, Cerulean continues to evolve, exposing the environmental costs of shipping and offshore oil extraction. Share your feedback through our user portal. For assistance, contact support@skytruth.org.
Why is Cerulean necessary?
Cerulean is designed to detect both acute and chronic oil pollution from vessels and offshore oil platforms. These two sources of oil pollution have created a growing problem in our oceans. Shipping vessels transport 80% of global trade by volume, and the vast majority use heavy fuel oil (HFO), one of the world’s dirtiest fossil fuels. The initial six-month pilot of Cerulean revealed a startling portrait: ships may be dumping more than 1.8 million barrels of oil per year into the ocean.
Meanwhile, offshore oil production is rapidly expanding to extract the world’s untapped reserves that lie beneath the ocean floor. The expected growth of shipping and oil development increases the likelihood of undetected pollution, resulting in devastating impacts to marine ecosystems, and to the health and ocean-dependent economies of coastal communities.
Cerulean in Action
Fighting Offshore Drilling in Latin America and the Caribbean
The Interamerican Association for Environmental Defense uses the law and science to protect communities suffering from environmental harm. They plan to use Cerulean to expand their work against offshore drilling, which is growing in the area despite serious risks to ocean biodiversity and the livelihoods of coastal communities.
Read More
Empowering Ocean Advocates
Andrew Dixon epitomizes the independent Cerulean user – a diligent watchdog for the waters surrounding Nikoi Island, his 37-acre resort off the east coast of Bintan, Indonesia. Since anyone with an internet connection can use Cerulean to track oil spills and its potential culprits, that is exactly what Dixon is doing.
Read More
Increasing Maritime Security in Indonesia
The Indonesia Ocean Justice Initiative works toward policies that promote ocean protection, sustainable use, and equitable welfare. They are using Cerulean to alert government officials when oil spills occur, and empower those whose livelihoods depend on the sea with scientific data about what’s happening in their communities.
Read more
Investigating the Overlooked Culture of Illegal Bilge Dumping in Europe’s Seas
SkyTruth collaborated with a team of journalists and media outlets led by investigative newsroom Lighthouse Reports to inspect the problem of chronic (and often illegal) oil pollution by vessels transiting European waters. SkyTruth’s investigation revealed the actual number of pollution events to be much higher than the officially reported statistics.
Read more
Exposing Biodiversity Loss in UK Waters
The climate advocacy organization, Uplift, alongside ocean advocacy group, Oceana, used Cerulean data to reveal how oil and chemicals released into UK waters by the oil and gas industry harm endangered whales, dolphins, seabirds, seals, and cold water reefs. They published a report revealing that these species are subject to a constant flow of small spills.
Read more
Early Findings
