Retrieval operations of derelict fishing gears give insight on the impact on marine life.

Abandoned, lost and discarded fishing gear (ALDFG), significantly impacts marine ecosystems and biodiversity by incidental capture known as ghost fishing. Such impacts were quantified during the Norwegian Directorate of Fisheries' annual ALDFG cleanup operation in September 2023 by examining the characteristics of retrieved ALDFG and recording the taxonomically sorted catch abundance and biomass. A total of 307 specimens equaling 382 kg of biomass were caught in the recovered gillnets and king crab pots.

Ghost fishing efficiency by lost, abandoned or discarded pots in snow crab (Chionoecetes opilio) fishery.

Marine pollution by lost, abandoned or otherwise discarded fishing gear (ALDFG) often has negative impact on the ecosystem through plastic pollution and continuous capture of marine animals, so-called "ghost fishing". ALDFG in pot fisheries is associated with high ghost fishing risk. The snow crab (Chionoecetes opilio) pot fishery is conducted in harsh weather conditions increasing the risk of fishing gear loss.

Effect of gillnet twine thickness on capture pattern and efficiency in the Northeast-Arctic cod (Gadus morhua) fishery.

Gillnets are among the most common fishing gears worldwide. They are often made of thin twine, which is prone to wear and tear, limiting the lifespan of the gillnet. This increases gillnet turnover, and consequently increased risk of gear discarding, gear loss, ghost fishing and marine pollution.

Effect of the Nordmøre grid bar spacing on size selectivity, catch efficiency and bycatch of the Barents Sea Northern shrimp fishery.

The introduction of the Nordmøre grid in shrimp trawls has reduced the bycatch of non-target species. In the Norwegian Northern shrimp (Pandalus borealis) fishery, the mandatory selective gear consists of a Nordmøre grid with 19 mm bar spacing combined with a 35 mm mesh size diamond mesh codend. However, fish bycatch in shrimp trawls remains a challenge and further modifications of the gear that can improve selectivity are still sought.

Comparison of the efficiency and modes of capture of biodegradable versus nylon gillnets in the Northeast Atlantic cod (Gadus morhua) fishery.

Modern gillnets are usually made of nylon with high breaking strength, suitable elasticity and durability making them an efficient fishing gear. Lost, abandoned, or discarded gillnets at sea cause plastic pollution and can continue capturing marine animals over long periods of time. Biodegradable materials are being developed to replace nylon in gillnets.

Can biodegradable materials reduce plastic pollution without decreasing catch efficiency in longline fishery?

Longlining is a widely used fishing method. During longline fishing, some of the snoods connecting the hooks to the mainline are often lost at sea. Since snoods are made of nylon or polyester, lost snoods contribute to marine plastic pollution.

Can vertical separation of species in trawls be utilized to reduce bycatch in shrimp fisheries?

Several shrimp trawl fisheries use a Nordmöre sorting grid to avoid bycatch of fish. However, small fish can pass through the grid. Therefore, the retention of juvenile fish often remains an issue during shrimp trawling.

Quantification of gear inflicted damages on trawl-caught haddock in the Northeast Atlantic fishery.

External damages are indicators of the overall quality of fish and fish welfare. Haddock is an important commercial species widespread in the North Atlantic, but few studies related to quality have been carried out on this species. We studied the levels of external damages on haddock captured with a demersal trawl in the Northeast Atlantic.

Quantification of bell-shaped size selectivity in shrimp trawl fisheries using square mesh panels and a sorting cone after a Nordmøre grid.

Shrimp trawlers in the Barents Sea use a Nordmøre sorting grid ahead of a small-mesh codend to avoid bycatch while catching shrimps efficiently. However, small fish can still pass through the grid to enter the codend, which increases their risk of being retained. In this study, we quantified the selectivity of a standard Nordmøre grid used together with one of two different codend designs, namely a diamond mesh codend with square mesh panels and a codend with a square mesh sorting cone section, for deep-water shrimp (Pandalus borealis), redfish (Sebastes spp.

Alternative bait trials in the Barents Sea snow crab fishery.

Commercial harvesting of snow crab () in the Barents Sea started in 2012 by Norwegian fishing vessels. This new fishery has significant bait requirements, representing an emerging conservation challenge. In this study, we evaluate the performance of five alternative (natural) baits manufactured from the waste stream of existing and sustainably managed harp seal () and minke whale () capture.

Catch and release patterns for target and bycatch species in the Northeast Atlantic deep-water shrimp fishery: Effect of using a sieve panel and a Nordmøre grid.

The Nordmøre grid and the sieve panel are two of the main devices used to reduce fish bycatch in trawl fisheries targeting shrimp species. However, even when using such devices, some small-sized fish enter the codend of the trawl together with the targeted shrimp. Therefore, bycatch reduction remains a problem in some shrimp fisheries.

Sequential codend improves quality of trawl-caught cod.

Trawl-caught fish are frequently associated with deteriorated catch quality. This study presents a new dual sequential codend concept with the aim of improving the quality of trawl-caught fish by minimizing the frequency and severity of catch damage. During towing, the fish are retained in an anterior codend segment with the legislated mesh size.