Tracking elusive and shifting identities of the global fishing fleet

Abstract

Illegal, unreported, and unregulated (IUU) fishing costs billions of dollars per year and is enabled by vessels obfuscating their identity. Here, we combine identities of ~35,000 vessels with a decade of GPS data to provide a global assessment of fishing compliance, reflagging patterns, and fishing by foreign-owned vessels. About 17% of high seas fishing is by potentially unauthorized or internationally unregulated vessels, with hot spots of this activity in the west Indian and the southwest Atlantic Oceans. In addition, reflagging, a tactic often used to obscure oversight, occurs in just a few ports primarily by fleets with high foreign ownership. Fishing by foreign-owned vessels is concentrated in parts of high seas and certain national waters, often flying flags of convenience. These findings can address the global scope of potential IUU fishing and enable authorities to improve oversight.

Satellite mapping reveals extensive industrial activity at sea

“…Each detection is thus provided with context in an area just over 100 × 100 km. We obtained the fishing and non-fishing labels from AIS vessel identities 26 .…”

“…Some vessel-tracking systems, such as the vessel monitoring system (VMS) used in fishing, are proprietary, which limit the ability to map and compare across regions 5 . For public mapping of ships, the focus has been on the automatic identification system (AIS) 24 , which broadcasts vessel coordinates to track vessel movements and support maritime safety; AIS data can also reveal vessel identities, owners and corporations, and fishing activities 5 , 25 , 26 . Not all vessels, however, are required to use AIS devices, as regulations vary by country, vessel size and activity 22 .…”

Unseen overlap between fishing vessels and top predators in the northeast Pacific

“…Intentional disabling has proven to be an actionable tool for detecting and charging vessels engaged in illegal, unreported, and unregulated (IUU) fishing activities ( 59 , 60 ). Unseen overlap with intentional disabling could be used to infer the species that vessels are fishing for in unauthorized locations ( 10 , 16 , 61 ) and subsequently transferring during unregulated transshipments ( 16 , 56 ). Unseen overlap with intentional disabling could be compared against fisheries dependent datasets to identify potential reporting discrepancies (e.g., the “Case study II” section) and noncompliance ( 42 ).…”

“…Although considerable strides have been made in recent years to map environmental ( 62 ), biological ( 63 ), and industrial ( 6 , 61 ) ocean conditions, our oceans remain data poor. Observational data are frequently only representative of a small proportion or area of the feature being quantified or mapped.…”

Securing ocean space for the sustainable development of small-scale fisheries

“…AIS data has been used in the past to measure incursions by prohibited large-scale shing vessels into African preferential access areas (Mullie, 2019;Belhabib et al 2020). However, there are global gaps in AIS coverage on large-scale shing vessels, so the data available is not comprehensive for the apparent shing effort of all such vessels(Park et al 2023). Increased availability of synthetic aperture radar (SAR) data may help ll these gaps to some extent(Paolo et al 2024…”