Global squid fishing increased by 68% between 2017 and 2020, according to our international analysis, prompting concerns that much of the international fishing fleet is sidestepping necessary conservation and management.
Our study, carried out with colleagues in Australia, Japan, the United States, Chile and Canada, and published today in Science Advances, reveals that almost all of the increase in squid fishing has occurred in unregulated areas, with 86% of squid fishing now occurring in places with little or no scrutiny of catch sizes.
Unregulated fishing poses a significant challenge to fishery sustainability and raises substantial equity concerns. While attention has tended to focus on illegal fishing, the growth in legal but unregulated fishing may pose an even bigger threat, particularly to species such as squid, whose fisheries can cover entire oceans.
To estimate the scale of global squid fishing, we analysed satellite imagery and vessel tracking data to see how many vessels are fishing for squid, and where and how often they operate.
Squid fishing vessels are typically outfitted with powerful lamps to attract squid to the surface. These lamps are so powerful that they are visible from space. This means we can use satellite data to spot these lights at night, along with data from the ships’ Automatic Identification System (AIS), which allows authorities to monitor the location and course of registered vessels.
Using this data, we estimate that the amount of light-luring vessel effort increased from an estimated 149,000 vessel days in 2017, to 251,000 vessel days in 2020. Of these, 61-63% were by vessels not broadcasting their AIS, and thus only visible by the loom from their lamps. This light-luring vessel effort represents an estimated total of 801,000 vessel days over the period 2017–20.
Finally, we correlated these data with national and regional management bodies, and determine how much of this activity is unregulated.