Monday, 29 March 2021 14:14

Electronic monitoring could be a potent tool

EM2 21 DKConvincing fishers to have cameras on board is an uphill battle

This article was featured in EUROFISH Magazine 2 2021.

Over 97m tonnes of fish and seafood were caught globally in 2018, according to the latest data from the FAO. Many fisheries are well regulated with catches at the maximum sustainable level, but others forego opportunities to improve yields, profits, and jobs because they are poorly managed, and yields are below the optimum level.

In addition, illegal, unreported, and unregulated (IUU) fishing is widespread depleting stocks, damaging the environment, penalising legitimate fishers, and is often associated with other illegal activities such as smuggling. Electronic monitoring (EM), the use of cameras and other electronic devices such as position and activity sensors, on board fishing vessels is becoming increasingly attractive to fisheries managers as a cost-efficient supplement to existing catch monitoring activities. While observers on board are customary in some fisheries in areas regulated by regional fishery management organisations, fisheries administrators, scientists, NGOs, and other stakeholders recognise the need for more comprehensive data on catches, bycatches, discards, fishing effort, and compliance with regulations.

Cameras could generate much useful data

Since placing observers on board all kinds of fishing vessels would be both impractical and expensive, EM has the potential to collect information that can contribute to resource management and provide the incentives to comply with regulations. According to the Environmental Defence Fund, an NGO, deploying EM is a way of allowing fisheries to reach their full potential, generate data for stock assessments, and help ensure compliance with regulations. Despite these advantages, as a paper by van Helmond and colleagues shows, EM has not found wide acceptance as managers are reluctant to deploy it knowing its unpopularity among fishers. The latter consider it an invasion of their private workspace and a reflection of official mistrust.

Trials of EM have been conducted in North America, South America, Europe, Australia, New Zealand, and the Pacific Islands among other places. The trials monitored catch, effort, handling, gear modification, and protected species, or some ­combination of these factors and they tested how suitable EM was as a complement or a replacement for on-board observers. The tests revealed that EM was feasible on a wide range of vessels, was more cost effective and scalable, and the availability of video enabled the data to be reviewed. Spanish trials of EM in the Atlantic and Indian Oceans led to two Spanish tuna purse seine associations adopting 100% coverage by EM, possibly the only programmes in the world that are managed by the industry itself rather than national or regional authorities. EM is also fully implemented in a few fisheries in North America, Australia and in tropical tuna fisheries in the Atlantic and Indian Oceans.

An independent reporting tool would eliminate bias, human error

Self-reporting tools such as logbooks suffer from certain constraints, among others, conflicts of interest. Information recorded accurately in a logbook may jeopardise future fishing opportunities if too many individuals of a protected species are caught, for example. Faithful reporting may be unintentionally coloured by bias or human error which can affect the reliability of records. Systems that independently record data are free from these pressures and offer other advantages as well. The data can be stored digitally and analysed later; they spare the fisher from paperwork; they can be deployed even on small vessels; they are cheaper than having observers on board while generating data that is comparable to that produced by observers; they can capture a wide variety of data that including on fish populations and habitat conditions that is useful for fisheries managers; they can work around the clock; they promote transparency enabling owners to monitor the activities of their vessels; by improving compliance with regulations; and by generating data the integrity of which cannot be compromised.

Studies have also shown that EM is cost effective compared with having observers on board. This is both because of the wider number of objectives (catch, effort, catch handling, gear modification, protected species, etc.) that can be monitored by the system and because the costs of the electronic components, sensors, cameras, data storage drives, etc., are falling even as their performance improves. In addition, the costs of software to integrate the components into a system, automated analysis of footage recorded, and data transmission are dropping all the time. Being able to dispense with the logistics of getting an observer on board a vessel is also a saving. Studies by NOAA Fisheries in 2015 showed that annual costs of electronic ­monitoring were about a third of those of having a monitor on board.

EM cannot do it all

However, EM systems also have their limitations. For example, they cannot collect biological data, such as otoliths, nor may they be able to monitor compliance with measures to reduce bycatches or discards if they do not happen on deck. Observers are also better at complex catch sampling operations. EM systems, like any other electronic equipment, can also fail, either breaking down or recording in poor quality if the camera lenses are not clean. The efficacy of an EM system also depends on the vessel where it is installed. Because of the lack of space, a small vessel may not afford the cameras an ­unimpeded view of the process they are to record. Other systems to monitor fishing activities include the use of patrol vessels and aerial surveillance, but these are estimated to be substantially more expensive than EM. Drones are also being used in some countries. All three, however, provide only a snapshot of the activities of the vessel.

In Denmark trials with EM started in 2008 and include one of the longest running pilots to test the potential of EM as a tool for fisheries management and control. In a paper in Fisheries Research from 2015 Kristian S. Plet-Hansen from DTU Aqua and his co-authors use the data from the trial to study the potential of EM as a tool for management and for monitoring compliance with the discard ban. The trial started in 2010 and continued to 2014 and was followed by a second phase carried out over the next two years. It initially covered fisheries in the North Sea, Skagerrak, and the Baltic Sea but after 2011 was restricted to fishing operations in the North Sea and Skagerrak. Among the conclusions the researchers came to was that the reliability of the EM system could be improved significantly with the help of relatively simple measures, such as correct positioning of the cameras and ensuring the lenses were kept clean. The ability to stream video data, which was not possible in the early stages, was a significant improvement as auditors could monitor the stream in real time and suggest improvements to camera positioning or crew behaviour that would increase the usability of the data.

Combining EM with an observer might be best to monitor compliance with the discard ban

In terms of monitoring compliance with the discard ban the scientists suggested that a combination of EM and on-board observers may be the most reliable as the disadvantages of each can be compensated for by the other. Observers enable the most sample detail but not the continuous coverage that cameras provide. Video analysis could be restricted to random samples which are then checked against electronic logbook entries. Mismatches between the two could trigger an audit of a higher number of video samples or even of the entire footage to confirm possible non-compliance. The authors suggest future improvements in hardware and software should enable automated video analysis that would be faster (and cost less) than manual audits and would open up other possibilities such as estimating the entire catch. However, they point out that video analysis does not allow estimations of fish age which is needed for scientific stock assessments. EM could link temporal and spatial data with the incidence of discards, information that fishers or managers could use to increase spatial or temporal selectivity and thus reduce discards. The authors also propose that despite its advantages the use of EM in the EU is not widespread because of fishers’ reluctance to adopt the technology citing privacy issues. In Denmark, fishers participating in trials of EM were given incentives in the form of quota top ups, though in other trials fishers have participated without being offered any rewards. In their paper van Helmond and his colleagues find that objections to EM from fishers stem from privacy concerns and the intrusiveness of monitoring. Sofie Smedegaard Mathiesen, a biologist with Denmark’s Fishery Association likens monitoring with cameras on board a vessel to surveillance in a prison.

Incentives may make fishers more amenable to camera monitoring

To address the opposition of fishers to EM they need to be convinced that there is something in it for them, such as increases in quota, greater flexibility to switch gears, or access to closed areas. Some fishers may also be persuaded by the potential benefits to them from EM data, for example, if the data identifies areas or seasons with high discards, it could be shared with fishers to encourage greater selectivity. Ms Mathiesen also points to the landing obligation (LO), EU legislation that demands that all fish regulated by total allowable catches (TACs) should be landed and counted against quota. The regulation forces fishers to land undersized specimens or individuals that would survive if returned to the sea. Instead of monitoring compliance with such regulations, she feels more effort should go into crafting better legislation that would benefit stocks. Her scepticism regarding the LO is reflected in the paper by van Helmond and his co-authors who suggest that it incentivises fishers to illegally discard small fish to retain quota to catch large fish of the same species. In mixed fisheries, choke species are also likely to be discarded in favour of target species.

EM2 21 DK M SchouWhen cameras are contentious and rules ignored, turn to economics

The debate seems to have shifted from one about ways to achieve healthy stocks to one about the merits and shortcomings of video monitoring. As things stand, despite the introduction of the LO, fishers still discard and authorities turn a blind eye. If legislation does not achieve its objectives, and monitoring is controversial, perhaps economics is the answer. Mogens Schou, a former ministerial advisor on fisheries policy in Denmark, states that if fishermen were given an increased quota comparable to the discard level in the given fishery on the condition that all catches were documented and counted against quotas, they would have every incentive to stop discarding. Instead of optimizing catches by discarding the least valuable fish, fishers would optimize catch-results by improving their catch methods to target only the most valuable fish. Extensive Danish and UK trials 2009-2014 reported this very clearly. In the illustration the red bars are the cheaper size 5 fish starting to show in catches for trial vessels when CCTV was installed in September.

EM certainly has its uses, but fishers are wary if not outright hostile to having it on board. Attempts to deploy it must involve fishers from the outset and it must be seen as a tool to help them fish better for themselves and the environment, rather than an instrument to monitor compliance. Mistrust of EM can also be allayed if it is introduced simultaneously in all Member States to ensure a level playing field for fishers across the EU.


van Helmond ATM, Mortensen LO, Plet-Hansen KS, et al. Electronic monitoring in fisheries: Lessons from global experiences and future opportunities. Fish. 2020;21:162–189. https ://
Schreiber Plet-Hansen, K. (2020). Fisheries data from electronic monitoring and traceability systems in the context of the EU landing obligation. Technical University of Denmark.
David C. Bartholomew, Jeffrey C. Mangel, Joanna Alfaro-Shigueto, Sergio Pingo, Astrid Jimenez, Brendan J. Godley, Remote electronic monitoring as a potential alternative to on-board observers in small-scale fisheries, Biological Conservation, Volume 219, 2018, Pages 35-45, ISSN 0006-3207,