Common whelk is a neo-gastropod that is intensively fished on the west and east temperate Atlantic with baited pots. The UK hosts the largest Whelk fishery contributing 10–15% to the national Shellfish landings, worth 15–27 million £ a year. The fishery is regulated by a minimum conservation reference size (MCRS) which for most areas is set at 45 mm total shell length. However, scientific information quantifying the size selec...

Pot fisheries are a crucial component of small‐scale fisheries worldwide, characterized by their low environmental impact, high species selectivity, and superior catch quality. However, these fisheries are often constrained by poor size selectivity, which results in substantial bycatch of juvenile target species and remains a major challenge for pot fisheries management globally. Incorporating escape gaps or increasing mesh si...

The Japanese mantis shrimp (Oratosquilla oratoria) is a commercially important crustacean species distributed around the coastal waters of China, which is harvested with both active and passive fishing gears. Among these, traps are one of the primary passive gears used in the Bohai Sea, which is one of the most important fishing grounds for Japanese mantis shrimp in northern China. However, the use of traps with a small mesh s...

White croaker (Pennahia argentata) is an ecologically and economically relevant fish species targeted by demersal trawls using diamond-mesh codends at fishing grounds in China, Japan, and Korea. However, the stock has been overexploited, and the capture of undersized individuals is of concern. Further, diamond-mesh codends are known to have varying mesh shape due to the fact that the opening angle in them varies along the code...

This study analyses the behaviour of cod ( Gadus morhua ), haddock ( Melanogrammus aeglefinus ), saithe ( Pollachius virens ) and redfish ( Sebastes spp.) in relation to size-sorting grids from video recordings obtained during trawling in the Barents Sea. It quantifies how fish contact the grid, how frequently they do so, their escape success rate and whether they squeeze themselves through the grid bar spacings during the esc...

In demersal trawls, ground gears are typically fixed to the fishing line to protect against the seabed and ensure seabed contact. Rockhoppers (RH) are among the most applied types of ground gears, especially in fisheries with rough seabed. However, their use has earlier been associated with substantial loss of catch under the fishing line and low catch efficiency. A new ground gear concept known as the semicircular spreading g...

In several demersal trawl fisheries flatfish constitute a large part of the catch, but often a significant fraction of these flatfish are unwanted species or sizes. To design trawls that are capable of addressing this problem, it is necessary to understand and quantify the size selection of flatfish species in trawls. Therefore, based on laboratory experiments, we tested the ability of different sizes of three flatfish species...

Saithe ( Pollachius virens ) is common in the Northern Atlantic and is often captured with demersal and pelagic trawls that comprise diamond mesh codends. However, size selectivity data is scarce for saithe. The meshes in these trawl codends have limited openness due to the drag forces acting on the catch accumulation in the aft end, which reduces escape opportunities for roundfish like saithe. Shortening lastridge ropes attac...

Calanus spp. are marine zooplankton that are considered as a potential source for aquaculture feed, due to their high abundance in the North Atlantic. The diminutive size (< 5 mm) of these zooplankton necessitates the use of fine-meshed trawls to harvest them efficiently. However, the use of fine-meshed trawls leads to high drag and thus energy demand to tow the trawl. Therefore, it is of importance to know the effect of mesh...