Aggregated Vessel Density and Fishing Effort Data (daily, monthly, annual) from VMS/ERS – Fish-X Project

Data content

The dataset contains harmonised spatial products generated through the Fish-X Insight Platform, the data-visualisation and analytics environment developed by CLS under WP4 of the Horizon Europe Fish-X Project. Insight supports the demonstration of a European fisheries data space by enabling the aggregation, anonymisation and dissemination of fisheries-dependent data for small-scale fisheries.

This dataset provides gridded maps of fishing vessel density and fishing effort derived from Vessel Monitoring System (VMS) and Electronic Reporting System (ERS) data. The raw VMS data were collected in real-time from pilot fishing vessels equipped with CLS NEMO vessel monitoring devices through three Fish-X use cases under WP5 led by WWF EPO : Portugal (SCIAENA, WWF Portugal), Croatia (WWF Adriatic), and Ireland (IIMRO). First-sales records were made available by DOCAPESCA in Portugal only and used by CLS to reconstruct fishing logbooks/Electronic Reporting System (ERS) data for the local pilot fishing fleet.

The following core variables are provided per statistical grid cell:

• Vessel presence (VMS-derived):

  • nb_vessels: number of distinct vessels present in the grid cell during the selected period,

  • nb_hours: cumulative number of hours spent at sea by vessels within the grid cell.

• Fishing effort (VMS-derived, AI-based estimation):

  • fishing_effort_passive_gear: apparent fishing effort for passive gears (gillnets, pots and traps, set longlines), expressed in hours × kilometre,

  • fishing_effort_drifting_longline: apparent fishing effort for drifting longlines, expressed in hours × kilometre,

  • fishing_effort_purse_seine: apparent fishing effort for purse seines, expressed in hours,

  • fishing_effort_handline_pole_line: apparent fishing effort for handlines and pole-and-line fisheries, expressed in hours.

• Catch reporting (ERS-derived, Portugal only):

  • nb_vessels_ers: number of vessels submitting electronic fishing logbook records within the grid cell during the selected period.

Spatial and temporal resolution

All variables are provided at daily, monthly, and annual temporal resolutions on a regular latitude–longitude grid with a spatial resolution of 0.025° × 0.025°.

VMS-derived variables are available for the period from 1 September 2023 to 30 November 2025 based on raw VMS data availability. ERS-derived variables are available only or the Portugal Use Case, for the period from 1 July 2024 to 31 December 2024.
For some days, no NetCDF file is provided when no fishing activity is detected at sea or when no grid cell contains at least three distinct vessels after application of confidentiality rules.

Annual products (2023 and 2025 for VMS, 2024 for ERS) are based on incomplete temporal coverage, depending on data availability. The effective temporal coverage of each file is explicitly documented in the NetCDF global attributes using time_coverage_start, time_coverage_end, and time_coverage_duration.

Data processing and confidentiality

All variables are aggregated into statistical grid cells following harmonised aggregation rules. 

Fishing effort is estimated by gear type using machine-learning methods applied to VMS trajectories, including automatic fishing-gear identification and detection of fishing activity phases. 

To ensure data confidentiality, information is withheld for grid cells containing fewer than three distinct vessels; no data values are provided for such grid cells in the dataset.

File format and standards

All files are distributed in NetCDF-4 format and follow the CF-1.8 conventions, ensuring interoperability with standard geoscientific tools and workflows.

Associated documentation

Detailed descriptions of variables, aggregation rules and fishing-effort computation methods are provided in the Fish-X Deliverable D4.3 – “Insight Platform v2.2 User Manual for Testing Users”, which serves as the primary technical documentation for this dataset.

Intended use

This dataset supports research and exploratory analyses related to fisheries activity, including:

• marine spatial planning,

• fisheries management studies,

• environmental impact assessments,

• data-space and interoperability demonstrations.

The dataset is provided for information and research purposes only and is not intended for operational control or enforcement.

Disclaimer

Funded by the European Union under Horizon Europe Grant Agreement No 101060879. Views and opinions expressed are those of the authors only and do not necessarily reflect those of the European Union or the European Research Executive Agency (REA). Neither the EU nor the granting authority can be held responsible for them.