Electronic Monitoring in Fisheries

Electronic monitoring (EM) systems generally consist of various activity sensors, GPS, computer hardware and cameras, which allow for video monitoring and documentation of catches and detailed fishing effort estimation. The sensors measure force on the net tow tables of net drum rotation, signaling setting and hauling of the net(s). In a common EM system setup the sensors were used to trigger the control box to start video recording during fishing operations. After the fishing activity on deck is recorded the cameras stop, to limit storage of “useless” footage. The cameras recorded overhead views of the working deck and catch-handling areas, while fishing, hauling, and processing the catches. The recorded footage can be reviewed at a later stage to obtain catch information, for example species composition, numbers, volume and lengths. It is still common practice that EM data is stored at exchangeable hard drives. Once full, hard drives are replaced by empty drives to continue recording. Drives were usually replaced by authorized persons, for example fisheries inspectors or staff of research institutes. In some cases, i.e. compliance monitoring, data encryption is provided to ensure data protection in the chain of custody, and making it also possible to send drives by mail service. Recently, new EM systems that allow wireless transmission of data via 3G, 4G, (5G) or Wi-Fi networks. To avoid manual replacement of hard drives and increased convenience of accessing EM data, it is expected that wireless trans mission will be progressively implemented in EM. The hypothesis is tested that cod catches are difficult to detect with video monitoring, specifically in catches with large volumes of bycatch. This mixed bottom-trawl fishery differs from fisheries where EM was proven to be a successful method at that time, e.g. hook and line or single-species fisheries with low bycatch volumes. In 2011, a pilot study started in which EM was used as an audit system to review the consistency of reported cod catches. In addition, the effect of the transformation from a landings to catch quota regulated system, e.g. the proposed EM regulation, was tested. The observed changes in fishing behaviour are described and analysed. Comparison of logbook records with video observations were done to test efficacy of EM for different size classes of sole (Solea solea) on board bottom trawlers. Results exposed the limitation of EM to detect the smallest size class, the discards, of sole on large volumes of mixed catch. These results gave already a strong indication of the potential problems the EU will run into after the implementation of innovative fisheries management. EM could be a powerful tool in providing data in research and, eventually, fisheries management. However, the uptake of EM in fisheries management in Europe remains low. To get a better understanding of the state of play, this thesis presents the insights gained from a review of 100 pilots studies and 12 fully implemented EM programmes worldwide and, within this context, discuss more specifically the European experiences with EM.