The increasing availability of tracking data from the Automatic Identification System (AIS) allows for studying the relations between fishing coastal communities and fishing grounds at an unprecedented level of detail, with respect to the more aggregated figures on fishing effort derived from logbooks and assembled through the Data Collection Framework at EU level. In this project JRC analyzed a large AIS dataset covering one year of activity of the EU fishing vessels above 15 meters of length. With this data JRC produced the first high-resolution map of fishing intensity covering all EU waters and examined the gravitation between ports and the dependencies of coastal communities on fishing grounds. From a socio-economic perspective representing and quantifying where vessels tend to gravitate in ports and their dependencies on the seaside is important to study the performance of fisheries at regional and local level. Other policy support applications include the assessment of impacts on the fishing sector from the establishments of Marine Protected Areas and Territorial Use Rights in Fisheries, and the quantification of indicators of the pressure on the marine environment and the sea floor, as foreseen by Descriptor 6 of the Marine Strategy Framework Directive (MSFD). The GIS tool presented here is primarily addressed to researchers and policy makers. It allows one to explore in great detail the intensity of fishing activity over all EU waters. After selection of a high intensity fishing area the tool shows the fishing coastal communities that relate to that area. Note that for confidentiality reasons, all information is aggregated from individual vessels to the level of ports and figures of dependency are presented only for ports with more than five vessels in the AIS data set.
The data analysed in this study consists of around 150 million positions reports from EU fishing vessels above 15 m of length, operating in FAO areas 27, 34 and 37, in the period between September 2014 and September 2015. Each AIS message provides the position of the vessel, its speed and a timestamp, at intervals of five minutes. These messages were classified as either related to fishing or to steaming through a classification algorithm based on the analysis of individual vessels’ speed profiles. This classification approach proved to be sufficiently robust in the case of trawlers, that represent the majority of vessels above 15 m of length. The total number of messages from trawlers classified as fishing was around 60 million.
A first layer in the GIS tool presents the frequency of these messages in a grid with a resolution of 1 by 1 km. From this layer, high intensity fishing areas were defined as those including cells with a frequency of messages above the upper quartile of the frequency distribution in each FAO subdivision.
The intensity of the relations between coastal communities and these areas was calculated on the basis of the number of messages falling in their respective boundaries. Similarly the main center of gravitation of the vessels on land and the relations between ports were calculated looking at the number of messages in the surroundings of the ports.
In the GIS tool additional information is provided for each port, namely, the total number of vessels registered from the fleet register, the estimated employment and Gross Value Added (GVA) and the coverage in terms of the number of fishing vessels for which AIS data was available.
A final layer included in the GIS tool presents the level of coverage of the AIS signal in EU waters. The level of coverage was calculated considering the ratio between received and expected tracks of merchant vessels. Contrary to fishing vessels, merchant vessels follow specific routes that can be derived even with incomplete tracks. The coverage map tells where the information is expected to be complete, and therefore where the information is more reliable.
More information on the methods and data used can be found in the listed references.
The fishing intensity raster and polygons are available for download at JRC Data Catalogue
The authors would like to thank MSSIS, courtesy of the Volpe Center of the U.S. Department of Transportation and the U.S. Navy, and MarineTraffic for providing the AIS data used in this study.
A detailed description of the methodologies was published in the papers below.