Innovation project selective shrimp fishery Wadden Sea

The Dutch fishing sector for Dutch shrimps (Crangon crangon) is innovating with the aim of improving the selectivity of the gears and fishing lighter, for example within the Innovation project selective shrimp fishery Wadden Sea.

Innovation project selective shrimp fishery Wadden Sea

Within the Innovation project selective shrimp fishery Wadden Sea, existing prototypes to improve selectivity and to fish more easily in the fishery for Dutch shrimps (Crangon crangon) were being further developed. This was done in collaboration between fishermen, net makers and scientists from the research institute Wageningen Marine Research (WMR).

Innovation in shrimp fishing

Those with the best ideas for gear modifications to improve selectivity or reduce fuel consumption are often the fishermen themselves. Whether the designs devised by them also work under the rough conditions at sea is the question, however. Field tests are needed to see how the gear adjustments behave under the influence of, for example, the water flow and the resistance of the seabed. Scientists thereby collect data in order to be able to determine with an objective view whether the modified gear produces the desired results.

This form of innovation is expensive: ships that are used can catch less than usual during the tests and the scientists have to be paid. If a promising prototype is available after an initial test period, it will be further developed to ensure that earnings are made that keep the fishing company profitable. The Innovation project selective shrimp fishery Wadden Sea is about the last part of the innovation process: preparing promising prototypes for use.

The following prototypes were tested in the project:

Alternative bobbin rope
Flexible panel
Wing bobbins and flexible panel
Sieve mat
Sorting grid for small shrimps
Flatfish sorting grid
Horizontal sorting grid

VIDEO – Innovations for shrimp fishing – WMR

Below is a brief description and main conclusions of three prototypes that provide sufficient starting points for further development. For more information, results and conclusions about all prototypes, see the scientific final report of WMR.

>> The final scientific report can be found on the website of WMR

Alternative bobbin rope

In a conventional bobbin rope, the bobbins hang in an arc under the beam of the fishing gear. Due to this shape, the bobbins cannot easily roll along on the seabed, resulting in the bobbins ‘digging’ when they are dragged over the seabed while fishing. With the alternative bobbin rope, all bobbins are positioned in the fishing direction.

Conclusions:

1-10% fewer marketable shrimps caught, depending on rigging and attachment of the bobbin rope;
No difference in bycatch at species level;
No difference in resistance between alternative bobbin rope and the conventional shrimp trawl;
Less wear on the rubber bobbins, but more wear on the metal frame around the bobbins;
Ground penetration and lower tractive power (fuel consumption) need to be further quantified.

Sieve mat

The shrimp fishery uses a sieve net to allow some of the unwanted bycatch to escape from the net. However, the seave net can quickly become clogged with jellyfish, bryozoans and/or seaweed. This can lead to a significant reduction in the catch of marketable shrimp. Cleaning the sieve net takes a lot of time (15-45 minutes), during which no fishing is possible. The sieve mat is an alternative to the sieve net that is selective, easy to use, controllable and quick to clean.

Conclusions:

Less catch of marketable shrimp in conditions with and without seaweed;
Better fishing opportunities due to fast cleaning time (3 minutes) in conditions with a lot of weed;
Bycatch of herring and shore crab in conditions without weed significantly lower, bycatch of gobies higher.

Horizontal sorting grid

The horizontal sorting grid is a V-shaped sorting grid that is positioned in a metal frame in front of the cod end. Small bycatch escapes from the net between the bars of the sorting grid. The bar spacing (6mm) ensures that no marketable shrimp can escape.

Conclusions:

20.7% less bycatch (mainly jellyfish, crabs and small non-marketable shrimp);
No significant loss of catch of marketable shrimp;

Future

The Nederlandse Vissersbond will work with WMR to explore how gear innovations in shrimp fishing can be followed up that provide sufficient starting points for further development and ultimately implementation in shrimp fishing. New ideas for gear innovation will also be included, both from the Netherlands and abroad.

Sustainability objectives

The sustainability objectives, such as improving the selectivity of the gears and fishing lighter, are laid down in the VIBEG agreement with nature organizations and the government. The sector has also been awarded the MSC certificate for sustainable fisheries, partly for these objectives. This project also anticipates the landing obligation regulation, which aims to allow European fishermen to innovate to fish more selectively.

Waddenfonds

The Waddenfonds allocated 60% funding for this project. The project started in the autumn of 2018 and has run for five years. The Nederlandse Vissersbond was the secretary of this innovation project on behalf of the entire shrimp sector. Together with the fisheries organizations VisNed and PO Rousant, the Nederlandse Vissersbond carried out the organizational activities to make the innovation possible.

Information links (in Dutch)

Innovation project selective shrimp fishery Wadden Sea

Project Details

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