Trawler fishing vessels 'Releixo' and 'Egaluze' going dark in Senegal and Gambia

Summary:

Between 2014 and 2015, trawler fishing vessels 'Releixo' and 'Egaluze' go dark in Senegal and Gambia in order to conduct illegal fishing activities. The ships were transmitting AIS signals for some of the time, and algorithms were then used to identify when the signal ceased for longer than 24 or 48 hours. Relaxio appeared to go dark to public tracking systems, around 21 times during a 19-month period between 2014 and 2015. Each incident lasted an average of 16 days, resulting in over 8,000 hours of unaccounted activity. Egaluze vanished from public AIS systems for 190 days when operating around the coasts of five African countries.

Reference URL

https://usa.oceana.org/reports/avoiding-detection-global-case-studies-possible-ais-avoidance/
https://www.nationalgeographic.com/science/article/illegal-fishing-ais-data-going-dark-protected-ocean-reserve-spd
https://www.wired.co.uk/article/ships-turn-off-tracking-systems-fishing-eu-investigate https://www.vice.com/en/article/d3wnzj/why-do-fishing-vessels-go-dark-in-certain-regions-of-the-ocean https://maritime-professionals.com/what-does-it-mean-when-fishing-boats-go-dark/