Port Buffer – Why is Apparent Fishing Effort Near Ports Now Filtered by Default?

What is the ‘Port Buffer’?

• To improve data accuracy, we’ve introduced a port buffer filter to the ‘Apparent Fishing Effort’ (AIS) map layer.
• This filter excludes fishing activity that appears within 3 kilometers of ports and anchorages.
• Vessels often move slowly near ports while anchoring, transiting, or waiting. In AIS-based models, this slow movement can easily be misclassified as fishing.
• The port buffer helps reduce these false positives, which can otherwise distort results—especially in dynamic area analysis reports or when reviewing coastal activity.

What Changed?

• We’ve added a port buffer filter to the AIS-based Apparent Fishing Effort layer.
• The filter automatically excludes AIS activity within 3km of known ports and anchorages.
• Users can adjust or disable this filter in the map’s layer settings.

Why 3 Kilometers?

After internal testing, 3km was chosen as the default because it effectively removes misleading near-port activity while still preserving legitimate fishing effort in nearshore areas. Platform users can set the port buffer to 1km, 2km, 3km (default), or 4km, or turn it off entirely.

How Can I Change or Remove the Port Buffer?

You can modify the port buffer in the Apparent Fishing Effort (AIS) layer:

1. Open the layer filter menu.
2. Locate the ‘Port Buffer’ filter.
3. Choose your preferred buffer distance or disable the filter.

Keep in mind that turning off the port buffer may reintroduce inaccurate data near ports, especially in areas with heavy maritime traffic.

What Does This Not Affect?

• The port buffer does not apply to fishing events that may be calculated along a track.
  • Use caution when interpreting fishing events close to ports or anchorages when reviewing individual or multiple vessel tracks.
  • Improvements to this will be made alongside improvements to the general fishing detection model in 2026 (see below)
• The port buffer filter is only applied to the AIS-based ‘Apparent Fishing Effort’ layer

What’s Next?

This update is a short-term fix to improve reporting quality and minimize errors. A longer-term upgrade to the fishing detection model is planned for 2026, which will more robustly address this issue without the need for a port buffer.