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A concept for innovative underwater passive tracking of lost fishing gear to support marine resource management; marine litter, sustainable fishing, hazards to navigation.

Challenge and vision

Abandoned/lost fishing gear have a significant and dangerous contribution to marine litter, illegal fishing, reduced resource
management, hazards to navigation and is been of great concern for the Food and Agriculture organization of United Nations.
Our vision; to develop a cost-effective passive high precision underwater identification and localization method of fishing gear
such as relevant problem owners (fishing sector authorities, commercial/leisure fishing) can significantly improve their
management of marine resources for which they are responsible and depend on.

Problem and need

FAO’s Code of Conduct states that the fishing gear should be marked in accordance with national legislation in a way that the owner of the gear can be identified. However, abandoned, lost or discarded fishing gear (ALDFG) is often impossible to identify as to fishery of origin. Marking the gear will provide a more effective way to the resource management, reduces risks / hazards to navigation, and reduces the environmental impact. Lost fishing gear that remain in the ocean and continue to fish without being emptied cause suffering to animals stuck but may also threaten fish stocks in the long run. An EU estimate shows that all fishing gear containing plastic accounts for 27% of the marine litter on the beaches, and that the EU fishermen dump or lose 11,000 tons of gear each year. In the Baltic Sea, it is estimated that 100 million lost yarn catches approximately 300 tons of cod annually. However, today marking of the fishery gear is not a common practice.

Both the fishing industry and leisure fishermen are using passive fishing gear like nets, pots and similar equipment. There where in 2017, 994 fishing vessels in Sweden using passive fishing gear however, The Swedish Agency for Marine and Water Management (SwAM), estimates that leisure fishing are even bigger and only the lobster fishing on the Swedish west coast estimates to approximately 5000 to 10000 persons with six pots each. About 3000-5000 pots are estimated to be lost every year.

SwAM has not quantified the economical loss on ghost fishing however, a modern lobster pot has a value of approximately 600 SEK which gives a loss of 2,4 MSEK only in lobster pots. Also, SwAM states that the lost gear does not only pose a threat with ghost fishing but also creates a lot of marine pollution that needs to be cleaned up; the annual costs for cleaning coastlines are estimated to 17 MSEK, and 33% of these costs are related to lost fishing gear.

Loss of fishing gear is a source of serious problems for marine life:
– Birds, marine mammals and non-targeted fish being caught in lost fishing gear.
– These gears are made of plastics that breaks down into macro, micro and nano plastics, which are ingested by marine species through food.

Socio-economic damage by, for example, degradation of beaches, leading to:
– Costs for cleaning beaches
– Loss of recreational values
– Attractiveness loss for accommodation in beach-front locations

Problems marine fisheries face due to ghost nets and marine litter has consequences in increased costs related to:
– Reduced catching income
– Remove junk from fishing gear
– Broken motors and propellers
– Emergency rescue services.

A trackable ID would help authorities with management, the industry and leisure fishermen would gain the possibility to find lost gear and recover it from the seabed as actually obliged by national regulations.

Project solution

After completing Step 3, we have developed a complete method and system for underwater identification and localization of fishing gear such that a better control of abandoned, lost or otherwise discarded fishing gear (ALDFG) is supported. This gives a better decision tool for fishing practices and resource management. This method and system could be a proposal for standardization for fishing gear identification under “Code of Conduct for Responsible Fisheries” from Food and Agriculture organization of United Nations (FAO) as well as national authorities.

The project’s solution offers a modular technology for underwater localization and identification allowing for simple identification (1 ID) or more complex (hundreds of IDs) with enough accuracy. In step 1 we will identify and evaluate different
types of techniques and measurement principles to then develop a method for underwater identification and localization for one or more of the different identified technologies.

On air-based applications, most used principle for identification is the wireless Radio Frequency identification (RFID) systems. For underwater application, the hydro-acoustic triangulation principle for finding objects is most used, but no technical solution exists yet for identification. A methodology that we already identified is the novel combination of acoustic triangulation with passive electro-acoustic RFID tags based on Surface Acoustic Wave (SAW). The elegance of this method is that it is chipless (doesn’t need an IC chip for Identification) and it is passive, thus the tag doesn’t need a battery. By tying the received acoustic
signature to the known type of programmed signal code, a specific passive SAW-RFID tag is identified. The transmitter will be placed on the vessel to allow for higher power consumption of the transmitter and thus longer reading distances. The transmitted signal can propagate up to 1 km in freshwater, so the main challenge is the design of tag antenna and SAW chip for the extra signal absorption in marine (salt) water. The design of the code reflectors, as well as signal processing are essential for the signal delay and recognition after reception of environmental echoes.

We also intend to develop and validate both theoretical and experimental model based on acoustic communication and calibration measurements for salt water. This model is an important part of the methodology of underwater localization and identification system that can deliver relevant data for system design optimization.

Testing of technique, not only in lab but in realistic environment is a prerequisite for our project which will be defined under stage 1 and further developed and validated together with our partners during stage 2 and stage 3, respectively.


  • Coordinator: Research Institutes of Sweden
  • Contact: Cristina Rusu (
  • Partners: Swedish Maritime Technology Forum, University of Gothenburg, Fiskarföreningen Norden
  • Funding: 500 kSEK (50 kEUR) from Vinnova (Sweden’s Innovation Agency), Challenge Driven Innovation
  • Duration: November 2018 – June 2019