Thousands of potentially illegal or environmentally damaging shipping and fishing vessels are sailing the world’s oceans under the radar, according to new research that reveals the extent of untracked activity at sea in unprecedented detail.
About 75% of industrial fishing ships and 25% of transport and energy vessels aren’t publicly tracked, researchers report Wednesday in the journal Nature. To fill in the gaps, a team of researchers analyzed satellite imagery from 2017 to 2021 of about 15% of the oceans’ surface where more than 75% of industrial activity takes place. They used artificial intelligence to classify objects in the images as infrastructure, fishing ships or non-fishing ships.
On average, about 63,000 ships were afloat at any given time during the analysis, nearly half of which were fishing vessels. Of those fishing vessels, roughly 75% weren’t publicly tracked, and this under-the-radar activity was concentrated around South Asia, Southeast Asia and Africa. Many untracked vessels were found in protected areas set aside for conservation, such as the Galápagos Marine Reserve and the Great Barrier Reef Marine Park.
The research raises concerns about the environmental impact of unregulated human activities at sea.
Most boats and ships are equipped with transponders that communicate their position to automated identification systems that track maritime traffic. Such automatic identification systems can help ships avoid collisions with other vessels and bolster government efforts to regulate their waters. But not all countries require ships to have such systems, and vessels engaging in illegal activity can simply turn them off, making it hard to see a global picture of ocean traffic.
The researchers also documented about 28,000 off-shore built infrastructure units, 48% related to wind energy and 38% used for oil production.
The extensive mapping effort “provides a more complete quantification of human activities in the oceans than ever before,” write Konstantin Klemmer and Esther Roth, geospatial researchers at Microsoft Research New England and Harvard University, respectively, in a companion article.
Better tracking could enable detection of illegal fishing operations and boost conservation efforts, they say.