To view different types of fishing vessel data, on the top of the left panel, we have the Activity section. Within this section, you can enable Fishing or Presence
- Fishing includes AIS and VMS data, so all the apparent fishing effort.
- AIS data can be filtered by flag and gear type.
- VMS data can be filtered by source, flag and, in some cases, by gear type, fleet and origin.
- Presence layer analyzes AIS data collected from vessels that our research has identified. The activity layer displays a heatmap of vessel presence. The presence is determined by taking one position per day per vessel from the positions transmitted by the vessel’s AIS.
- The Presence layer can be filtered by fishing, carrier and other vessel types.
- The night lights vessel detections layer, known as visible infrared imaging radiometer suite or VIIRS, shows vessels at sea that satellites have detected by the light they emit at night. Though not exclusively associated with fishing vessels, this activity layer is likely to show vessels associated with activities like squid fishing, which use bright lights and fish at night. Global Fishing Watch has used a sophisticated matching system to match night light vessel detections with AIS information to identify vessels emitting light, and those that aren’t transmitting their identity. This matching is done using a probabilistic model that determines AIS-message/VIIRS-detection pairs based on all available AIS records right before and right after the time the VIIRS image was taken, as well as the probability of pairing a specific AIS message to any of the vessels appearing on that image.