Integrating remote sensing in fisheries control

Abstract To complement existing fishery control measures, in particular the Vessel Monitoring System (VMS),a pilot operational system to find fishing vessels in satellite images was set up. Radar is the mainstay of thesystem, which furthermore includes fully automated image processing and communication protocols with theauthorities. Different image types are used to match different fisheries – oceanic, shelf and coastal. Vesseldetection rates were 75–100% depending on image type and vessel size. Output of the system, in the form of anoverview of vessel positions in the area highlighting any discrepancies with otherwise reported positions, can beat the authorities within 30 min of the satellite image being taken – fast enough to task airborne inspection forfollow up. KEYWORDS : compliance monitoring, fisheries control, remote sensing, satellite observations, Synthetic Aper-ture Radar, Vessel Monitoring System.IntroductionEcological depletion caused by overfishing precedes allother pervasive human disturbance to coastal andmarine ecosystems, including pollution, degradation ofwater quality and anthropogenic climate change(Jackson et al. 2001; Conover & Munch 2002; Myers& Worm 2003). Changes towards more sustainablefisheries occur slowly.The main reasons for the collapse of many Europeanstocks are identified and discussed in the CommissionGreen paper (European Commission 2001) andinclude:1 fishing industry does not feel sufficiently involved insome important aspects of the policy;2 the current fishing fleet is much too large to besustainable;3 fisheries management has failed so far to implementa long-term strategy;4 monitoring and control of fishing activity suffersfrom fragmentation – inspection resources could bemore efficiently allocated;5 scientific advice still has significant gaps andweaknesses.In addition, for individual fishing enterprises, thestrongest incentives are toward short-term gains – inpart because fish stocks are openly accessed.A breakthrough was achieved when the Council ofthe European Union introduced the Vessel Monitor-ing System (VMS) regulation (European Council1992), obliging all European fishing vessels longerthan 24 m, as well as those fishing in Europeanwaters, to submit their position to either the flag stateor the coastal state at given intervals. A furtherregulation (European Council 2002) was introducedin December 2002 extending VMS to all vesselslonger than 15 m. VMS positions are obtained onboard from GPS, and transmitted via satellite com-munication in real time to a Fisheries MonitoringCentre (FMC), which is present in each Europeancountry. The interval is typically hourly, and mostsystems also allow polling, i.e. response to a positionrequest from the FMC. The FMCs in this way havecontinuous information on the whereabouts of theirnation’s fishing vessels.The VMS has given an enormous insight into thedynamics of fisheries all over the world. Although itsvalue in improving fisheries control became apparentimmediately, it soon became clear that more informa-tion has to be coupled with it to maximise itsimpact. To this end, the fisheries authorities turnedto space-borne remote sensing using Earth Observa-tion (EO) satellites (European Commission 2003). EOsatellites produce images of (in this case) the sea