Scientists Are Shedding Light on ‘Dark Vessels’ at Sea

The ocean is a major industry hub, acting as a marine highway for shipping vessels, a connector for transport ships and cruise lines, and a critical food and economic resource for the world’s fishing fleets.

However, this sprawling marine ecosystem, which covers more than 70 percent of the planet, also provides a perfect place for unregulated human activities to hide in plain sight, experts say. A recent study revealed just how much fishing activity is slipping under the radar, finding that roughly three-quarters of the world’s industrial fishing ships are not publicly tracked. 

“The reason this matters is because it’s getting more crowded [at sea] and it’s getting more used and suddenly you have to decide how we’re going to manage this giant global commons,” David Kroodsma, director of research and innovation at the nonprofit Global Fishing Watch and co-lead author of the study, told The Verge. “It can’t be the Wild West. And that’s the way it’s been historically.”

This undetected and unregulated activity poses serious ethical and environmental risks, but scientists are tapping into a variety of technologies to shed light on these “dark vessels.” 

Satellite Watchdogs: In many parts of the world, marine vessels are required to carry a small box onboard known as an Automatic Identification System (AIS), which emits radio signals that broadcast their location at sea to government officials and other boats.

However, AIS signals don’t always reach the satellites that track them in remote parts of the ocean where reception is poor. Other times, fishing vessels can intentionally flip off their AIS if they want to go dark, a strategy that some use to hide criminal activities, the study’s authors say. 

“On land, we have detailed maps of almost every road and building on the planet,” Kroodsma said in a statement. “In contrast, growth in our ocean has been largely hidden from public view.”

To fill in the gaps from traditional technology, the authors recruited the help of a different space watchdog: the European Space Agency’s Sentinel-1 satellite constellation. Using deep-learning machine models, the researchers sifted through 2 million gigabytes of satellite imagery captured from 2017 to 2021 in areas of the ocean where the majority of industrial activity takes place. 

They found that untracked activity is largely concentrated in Africa and South Asia, and spotted many dark vessels cruising inside marine protected areas.

Wildlife Risks: Humans aren’t the only ones merging onto the ocean’s marine highways; a number of highly mobile ocean species such as sea lions, sharks and leatherback sea turtles traverse long distances of the sea as they migrate. 

In busy industrial areas, these animals can get entangled in fishing nets as bycatch or get caught in the crosshairs of shipping lanes and become “ocean roadkill,” an issue I covered in October. 

It turns out marine biodiversity may be even more threatened than previously thought “because of large numbers of dark fishing vessels operating where these species live,” Heather Welch, a marine researcher at the University of California, Santa Cruz and the NOAA Southwest Fisheries Science Center affiliate, writes in the Conversation. 

For a study published in March, Welch and her colleagues mapped the overlap between the habitat areas of 14 marine predators with a 2022 global dataset that revealed hotspots where commercial fisheries’ AIS are disabled. They found that dark vessel activity increases the risks to marine predators by nearly 25 percent, with particularly high dangers in the Bering Sea and along the Pacific coast of North America. 

The team did not account for vessels that do not use AIS, which means “risk calculations likely still underestimate the true impact of fisheries on marine predators,” Welch writes in the Conversation. 

What now? Illegal, unreported and unregulated (IUU) fishing can lead to rampant criminal activity, from human rights abuses to overexploitation. These issues have been covered extensively by The Outlaw Ocean Project, a nonprofit journalism organization founded by journalist Ian Urbina. 

Shedding light on the impact of dark vessels specifically could help countries better regulate fisheries, such as by setting catch limits for species like tuna in high risk areas, according to Welch’s study.

It could also be crucial to following through with conservation goals at a global level, the Verge reports. In 2023, nearly every nation around the world signed onto a goal of protecting 30 percent of the Earth’s land and sea by 2030. 

“The question is which 30 percent should we protect? And you can’t have discussions about where the fishing activity [and] where the oil platforms are unless you have this map,” Kroodsma told the Verge.

In other places, people are taking the illegal fishing issue into their own hands. For example, a fisherman in Italy is working with artists to thwart illegal bottom trawlers, which drag large nets across the seafloor, using underwater sculptures that snag the criminals’ equipment, Tristan Kennedy writes for Wired.  

More Top Climate News

On Tuesday, the U.N. officially confirmed what many other organizations had already broadcasted: 2023 was the hottest year in human history by a “clear margin.” 

Celeste Saulo, the secretary-general of the World Meteorological Society—the U.N. division that focuses on climate, weather and water resources—said that the organization is “sounding the Red Alert to the world.”

The report also stressed unprecedented sea-level rise due to glacial retreat, droughts that led to water insecurity and widespread biodiversity loss. 

The primary “glimmer of hope” that the report spotlights is the recent rise in renewable energy capacity, which surged by nearly 50 percent in 2023. However, the heat is already taking its toll on communities around the world. 

In mid-February, a devastating heat wave hit the southern part of West Africa, and a new report suggests that climate change made this event 10 times as likely. Researchers have not determined the extent of how this heat affected individuals in the region, but they do know that many residents lack access to enough water or air-conditioned spaces, reports The New York Times. 

“People are left with very limited options for individual coping strategies,” Maja Vahlberg, a risk consultant at the Red Cross Red Crescent Climate Centre and co-author on the analysis, told the Times.