Obtaining stock data and implementing effective controls

EM6 21 FISHINGThe digitalisation of the fishing industry is moving ahead

This article was featured in Eurofish Magazine 6 2021

Despite many improvements, regional overfishing, bycatches and discards remain unsolved problems for the global fishing industry. Catch quotas, controls at sea and in ports, area closures and fishing bans do help, but are not satisfactory solutions. It would be preferable if unwanted fish did not get caught in fishing gear in the first place. Innovative technologies are giving hope for new solutions.


The commercial fishing industry produces over 90 million tonnes of fish and seafood every year and employs many millions of people. But although the fishing industry is heavily regulated in many locations, some problems remain, such as illegal, unreported and unregulated fishing (IUU), overfishing, bycatches and discards. Fish are often caught before stocks have a chance to recover. According to the FAO, approximately one-third of fish stocks worldwide are overfished. There is therefore an urgent need for action to preserve ocean ecosystems, maintain the foundations of the fishing industry and secure attractive jobs. However, these challenges cannot be met with strict regulations and controls alone. Functioning monitoring of fisheries and compliance with all regulations are doubtless important elements in fisheries management. But reliable data for the scientific assessment of stocks in order to be able to determine sustainable catch thresholds is often lacking. However, such data is indispensable in order for the fishing industry to be able to operate sustainably. Unfortunately, no generally accepted universal best practice exists to reach this target and to combine supplying fish to the global population with legitimate environmental protection priorities. The overall package of required management measures includes many sub-steps, including technical
changes to fishing gear as well as fishing area and fishing effort ­controls.

There is a significant need for innovation in this area. Although fishing fleets have reduced globally since the mid-1980s and overcapacity has declined, the construction of new, modern and resource-conserving fishing vessels has remained significantly behind expectations. Because there was a lack of demand and a market for innovative fishing technologies, manufacturers hesitated to make urgently needed investments in improving fishing expertise. The consequences of this are being felt now, as fishing has become significantly less attractive in many Western countries, and there is a lack of young fishers almost everywhere. In order to attract more young people to the profession, qualified crews and resource-conserving vessels with advanced equipment and fishing gear that give the industry a future-oriented perspective are required. It is the younger generation that has the highest levels of environmental awareness and would like to be involved in science-based ­fisheries management. However, obtaining high-quality basic data on the fishing industry is very difficult with outdated gear and technologies. In order to enable fishers to act independently and with awareness, they need new kinds of infrastructure, more intelligent fishing technologies, multifunctional catch monitoring sensors and high-performance software for analysis and visualisation of the data collected.

In addition, the monitoring of fisheries must be expanded, because comprehensive controls at sea are not really possible with standard methods. On-board cameras for monitoring catches and discards are just one element of the overall concept, since monitoring objectives can vary significantly from fishery to fishery. It only makes sense to use technologies, sensors, data storage, data transmission devices and software if the data obtained from them can, if necessary, meet the standards for evidence that can be accepted in court. Catch quotas, days at sea and other fishing restrictions are helpful but in the final analysis are very blunt management instruments to limit fishing-related mortality to a level that allows for high and sustainable returns in the long run. The best way to avoid discards is to prevent non-target species from being caught and hauled on board in the first place. However, fishers can only avoid unwanted bycatches if they know what is swimming in their nets. Currently, attempts to solve the bycatch problem are primarily focused on passive protective measures related to fishing gear. These include size-selective sorting grids and exit windows that allow undersized animals and unwanted fish species to escape from nets. However, this does not always work as desired. A better option would be active bycatch prevention systems, for example systems that open trawl nets in a targeted way if too many young fish, unlicensed fish species or other non-target fish get into the nets.

Trawl nets should no longer be black boxes

This requires sensitive sensors that record all fish entering the net, and not just their number, but also, as far as possible, the sizes of individual animals and their species. This data must be transferred in real time to the central command of the fishing vessel. Ideally this should be done wirelessly, because additional cables could cause disruption or become damaged among the tangle of sweep lines and other net lines. Wireless sensors therefore require an independent power source and must be as durable as they are sensitive in order to be able to withstand the dynamic and water pressure underwater. Because this complex requirements profile is very demanding for technology manufacturers, these kinds of catch monitoring sensors are currently supplied only by a few specialists. One example is Simrad, which meets a variety of demands with its PX series sensors. Simrad’s PX sensors are multifunctional, which means that they complete multiple tasks as standard, and they include options to record up to five measurements simultaneously. All data recorded is transferred to the vessel wirelessly via coded acoustic signals. The vessel then records these signals using a hydrophone and forwards them to the catch monitoring system. There, incoming information is evaluated and visualised using special computer programs.

The wide range of services that they provide make PX sensors ideal tools for communication between the trawl net and the fishing vessel, making significantly better catch control possible. Measurements that would previously have required multiple different sensors can now be recorded with a single sensor. Simrad’s PX MultiSensor is suitable for both trawl and purse seine nets. The PX TrawlEye even has an integrated echosounder that makes detailed recording of the fish in the trawl net and the sea floor structure possible.

The 3D Sonar Visualizer F3D-S from Furuno provides a similar range of functions to represent fish data and the sea floor in a real 3D view. Information on the fish caught, the fishing effort and the trawl path of the net is presented visually. The precise image of the sonar package makes it easier for both professionals and laypersons to understand the situation under the water, which is very helpful when it comes to appropriate responses. Camera systems installed in different positions in the net are increasingly developing into valuable aids to fishers for better monitoring and controlling fishing processes. Combined with the right software, their performance is already very significant and developments in this area keep advancing. With CamTrawl, a sideways facing digital stereo-camera system fitted near the open cod-end of a traditional trawl net, fish and small or transparent marine organisms, for example, can be precisely recorded, which was not possible with older technology.

Real-time observations make rapid intervention possible

Systems that combine camera images with hydroacoustic sonar data obtained from sensors on trawl nets enable an even deeper understanding of the world under the water, the net position and the catch. However, the development and manufacture of complex equipment such as the FX80 system, for example, often requires the cooperation of multiple highly specialised companies. Simrad, the camera specialist Kongsberg and Trawl Products Division, among others, were involved in the FX80 technology. However, sensors and camera systems do not always need to be developed from the ground up. Where possible, manufacturers are adapting existing, tried-and-tested devices, expanding their possible uses. JT Electric, for ­example, ­manufactures underwater camera systems for use in trawl nets that supply video images of net inlets. However, a big disadvantage of the original devices was that they could only display and evaluate the data once the trawl net was back on board. This meant that the skipper in charge of the vessel could analyse the most recent catch retrospectively, but could not actively intervene during trawling to change something. The logical next step to improve the system was therefore to add a new level of functionality to make the live streaming of data possible. JT also added a remote light to its camera system that eliminates backscatter in the water, lights up a larger area of the fishing gear, improves range and thus supplies better images.

The two light HD trawl cameras from LH Camera that record sharp videos in the trawl net in full HD quality also provide this functionality. They save the video images internally on an integrated recorder, but can also transmit the recordings live to the surface. Their 120° wide-angle lens covers a wide image area in the net. The Deep Sea Trawl Camera, weighing just under 2 kg, is even suitable for deep-sea fishing, as it withstands water pressure down to 1,500 metres below the surface.

An important prerequisite for fishing in a way that conserves resources is often overlooked, because in order to be able to fish according to quotas, the fisher must of course know how many fish they already have on board their boat. Gravimetric measurements to determine weight were previously not technically feasible on unstable platforms such as fishing vessels. Determining how many fish baskets (usually 40–50 kg each) of each species that the catch filled was the method most commonly used to record weight. This offered creative fishers a certain amount of leeway to exceed the permitted catch quotas. In the meantime, however, movement-compensating intelligent weighing systems have been developed. They can accurately measure, calculate and save the gross weight of the catch despite the movement of the vessel. Modern versions of these smart weighing systems can even report the data via satellite directly to fish markets and ports in order to update the predicted landing. Weighing systems such as these can often also interact with the RFID tags on the fish crates, which opens up interesting possibilities for catch traceability. Beyond catch weight, modern RFID tags also save other important information such as the vessel ID, the fishing location and the fishing date, fish species and sizes as well as other data. Overall, smart weighing technologies offer fisheries management the opportunity to monitor compliance with catch quotas more precisely than ever before and potentially to issue fishing bans for specific areas. Obstacles to installing these scales on smaller fishing vessels include, for one, the relatively high acquisition costs (sea-going scales cost 6 to 8 times more than weighing systems on land), and legal reasons, since weighings at sea are not recognised in court as evidence in all countries in the event of a legal dispute.

In-person inspections remain indispensable

The above points alone demonstrate that fisheries management cannot do without regular controls at sea. In the 1982 United Nations Convention on the Law of the Sea, coastal states bear the responsibility for the use of resources in their exclusive ­economic zones (EEZs). Since then, almost all developed states have increasingly been using electronic control methods as part of their regular MCS (monitoring, control and surveillance) activities, in addition to air monitoring, on-board observations and inspections at sea. This is particularly true on the open seas, which, due to their vast extent and the number of and distances between vessels, take huge amounts of effort to monitor. The on-board electronic monitoring devices have two essential tasks. First, they monitor whether fishers are acting in a legally compliant manner while at sea and, for example, if they are actually observing all regulations such as the requirement to land the whole catch and bans on discards. Second, they also provide important basic data for fisheries management. Fisheries scientists need reliable information on vessel positions, catch quantities, fish sizes and discards in order to be able to estimate the stock situation and possible catch quantities with enough certainty. The more data is incorporated into the forecasts, the more reliable the calculations are.

Satellite-supported vessel monitoring systems (VMS) supply valuable information on the physical and temporal distribution of trawl net fishing. This makes it possible, for example, to examine whether closures of areas to fishing vessels are being observed or ignored. Using additional data, the unit catches (catch quantities per unit of time) for specific sea regions can also be calculated, which in turn enables conclusions to be drawn about overfishing. If there is a decreasing unit catch trend, this is an important indication of overfishing. A central task for the monitoring of sea waters with VMS is the curbing of IUU fishing. However, this technology is not suitable to monitor illegal discards or compliance with the obligation to bring all catch to land. These tasks are more suited to the methods of electronic remote monitoring (EM), where high-resolution cameras keep an eye on fishing-relevant areas of the vessel and record around the clock. When compared with fishery monitoring from the air or with patrol vessels, such video recordings systems have the advantage that they can be implemented on all ships almost without limitation seven days a week, i.e. they allow for comprehensive control. And for a much lower cost than would be possible with expensive on-board observers.

The fishing profession must be future-proofed

Since 2008, some EU countries have already carried out multiple EM studies with different goals and a variety of different technologies. The North Sea countries tested the first commercial EM system in the world, the EM Observe program, during the period of 2008–2016. The AnchorLab black box system was developed to further support EM tests in Denmark. The Electronic Eye (eEYE) by Marine Instruments was used on Spanish tuna purse seine vessels primarily to monitor bycatch of endangered, threatened and protected species. The iObserver system developed by the CSIC scientific institute in Spain, on the other hand, supports the development of algorithms for automatic species recognition and size estimation of fish that move past the lens of a camera on conveyor belts. CatchScanners, which scan fish with lasers, are helpful in combating infringements of the rules. They generate 3D colour images of the fish that can be analysed with the help of artificial intelligence to estimate the weight and identify the species. However, these systems have not been fully automated and cannot get by without human intervention, particularly in the assessment of the recorded film material. Nevertheless, work is being done on the development of more efficient analytics software and leaner processes in order to significantly shorten monitoring times. Advances in the areas of artificial intelligence, machine learning and automated image analysis give rise to hope that the time and costs required will continue to decrease in the near future.

The resistance of many fishers to some MCS tools and to on-board camera monitoring can perhaps be overcome with incentives such as higher shares of the quota, more days at sea, improved access to fishing waters or more flexible use of fishing gear. A reversal of this trend is unlikely, since the advantages of innovative and practical MCS solutions in the fishing industry are obvious. Smart technologies are also rapidly advancing in the fishing industry – the technological transformation and digitalisation of the fishing industry have already begun. To fishers who are deeply anchored in tradition, sensor technology, GPS and video cameras both in nets and on deck may be unfamiliar or be seen as disruptive, but these technologies contribute to making the fishing industry more sustainable and making the profession more attractive and future-proof. However, the future of the fishing industry may look quite different to what we can imagine today. In the SmartFish H2020 project, a team managed by SINTEF Ocean are working on the development of intelligent fishing gear, including, among other solutions, the new SmartGear trawl net. It produces noise when used in the sea and uses flashing LED lights of differing colours and intensities that only entice target fish species into the net, while unwanted bycatch species are scared off.



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