New study shows where fishing vessels disable detection devices
From 2017 to 2019, fishing vessels turned off their detection devices, leaving nearly 5 million hours of fishing activity unexplained. A new research intentionally disables automatic detection system devices and shows that one of the disabling hotspots occurs in US waters off the coast of Alaska.
new study, “The Hotspots of Undiscovered Fishing Ships”Posted on November 2 in the journal science advance and presents the first global dataset of disabling AIS in commercial fisheries, which obscures up to 6 percent of vessel activity. This work, which was supported by the Catena Foundation and NOAA’s Office of Law Enforcement, provides a global analysis showing that fishing vessels’ detection devices have been turned off.
Lead author Heather Welch, a project scientist at the Institute of Marine Sciences at the University of California, Santa Cruz (UCSC), worked on the study with researchers from Global Fishing Watch and NOAA Fisheries. While maintaining a dataset of vessel activity, Global Fishing Watch developed a machine learning method to intentionally separate AIS from gaps in satellite coverage and other technical issues, identifying the major reasons Welch had to discontinue AIS equipment. allowed to do so.
Originally designed as a collision avoidance tool, automatic identification systems or AIS for short can be disabled intentionally—sometimes for legitimate reasons, and other times in an attempt to conceal illegal activities. This is what this new research shows: The analysis uses automatic identification systems, or AIS, data to provide information about global fishing activity, including illegal, unreported and unregulated fishing.
“AIS data can tell us a lot, but it can also be lacking,” said co-author Tyler Clawell, data scientist for Global Fishing Watch. “We may not always be able to see what ships are doing, but knowing that they are deliberately concealing their movements provides valuable information that managers and scientists did not have before. Having a better understanding of what is hiding allows officials to deploy more strategically valuable water resources, supporting better fisheries management.
Using equipment developed by Global Fishing Watch, which National fisherman Covered in an article last July – An interactive map for monitoring dark fleet activity in coastal waters —Heather Welch, project scientist at UCSC and lead author, was able to identify four primary causes of AIS being disabled.
The team first developed a rule-based classification model to identify which gaps in AIS transmissions may have been caused by intentional incompetence, and reveal the locations, flag states and gear types in which the most Overfishing is obscured by disabling vessel activity.
They then used a popular machine learning method called Boosted Regression Trees to identify the primary drivers of suspected AIS that could be related to the quality of fishing land, piracy, transshipment and jurisdiction boundaries. Disabled from a suit.
Four hotspots of undiscovered fishing vessels
Heather Welch said, “There are some valid reasons why ships disable their AIS, but we found two situations in which this is done for potentially nefarious reasons, either for fishing in unauthorized locations or to obscure unauthorized transshipment.” to do.” “This dataset is now operational, and the data is generated in real time, so it can be used to target inspections and improve fisheries management.”
In the study, researchers identified more than 55,000 suspected intentional disabling incidents from 2017 to 2019 that obscured nearly 5 million hours of fishing vessel activity. More than 40 percent of the total hours obscured by suspected AIS disabling occurred in four geographic locations identified as hotspots, three of which are areas of concern for illegal fishing: the Pacific Northwest and the Exclusive Economic Zones of Argentina. (EEZ) adjoining regions and West African nations. These areas have rich fishing grounds with limited management oversight.
The study indicates that incidents of disabling were concentrated in waters adjacent to EEZ boundaries, suggesting that ships may disable AIS before entering unauthorized locations for illegal fishing. “In many cases, ships ‘go dark,’ disabling their AIS as they approach the edge of the EEZ where they are not authorized to fish,” Welch said. “For example, you can see a Korean-flagged ship headed for Argentina, and then it goes dark in international waters outside Argentina’s EEZ.”
In particular, disabling was particularly common with overlapping claims within and around the EEZ, such as the Falkland Islands (Malvinas) which are disputed by the UK and Argentina. Political conflicts in these areas can create blind spots for enforcement.
Incidents of disabling were also common in areas with high transshipment activity, where ships transfer their catches to refrigerated cargo ships. According to the study, “Transshipment can be an effective way to catch back on shore and resume fishing quickly, but it can also be used to obscure illegal fishing activity, effectively Illegal “laundering” can be carried out through a cargo vessel. In addition, it can foster conditions that allow forced labor on fishing boats, which rarely return to ports. “
Disabling AIS to Avoid Pirates
The study also found evidence that some incapacitated by ships engaged in legal activities for less nefarious reasons. In some cases AIS can be disabled to hide the locations of good fishing grounds from competitors. The fourth disabling hotspot was caused by the disabling of American trawlers in US waters off the coast of Alaska – one of the most intensively managed fishing grounds in the world.
Research shows that ships flagged to the four major nations lost 82% of the time in suspected disabling incidents in waters more than 50 nautical miles from shore. Spain had the highest fraction of vessel activity due to disabling incidents (up to 14%), followed by the United States (up to 8%), Chinese Taipei (up to 6%), and China (up to 5%). The researchers point out, however, that “AIS use is biased towards flagged ships in upper- and middle-income countries, thus, these results, in part, reflect who uses AIS (higher AIS use is more likely to disable AIS). leads to higher opportunities).
Another reason for disabling a ship’s AIS is to protect the ship and crew from piracy. Using a database of past events, it is clear that ships have historically turned off AIS in dangerous waters to prevent the ability of others to track and intercept them. The approach demonstrated in this study can be used to support surveillance and enforcement efforts.
“This new dataset is an untapped resource that provides a real opportunity to trace previously observed behavior and illegal fishing activities,” Welch said. “Officers can use this information to decide where to send surveillance drones or patrol vessels, and it can also be used to focus port inspections on vessels that have entered or near EEZ borders. AIS has been disabled in the transshipment hotspot.”
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