Conservation Evidence: Evidence Data

Collected Evidence: Collected Evidence: Use artificial light on fishing gear Two studies examined the effects of using artificial light on fishing gear on marine fish populations. One study was in the Pacific Ocean (USA) and one in the Barents Sea (Norway). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (2 STUDIES) Reduction of unwanted catch (1 study): One replicated, paired, controlled study in the Pacific Ocean found that shrimp trawl nets with artificial lights caught fewer unwanted fish when they were fitted to the fishing line, but not to a size-sorting grid, compared to a conventional trawl. Improved size-selectivity of fishing gear (1 study): One replicated, controlled study in the Barents Sea found that size-selectivity of long rough dab, Atlantic cod, haddock and redfish was not improved by the presence of LED lights on a size-sorting grid. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2695https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2695Wed, 02 Dec 2020 17:04:07 +0000Collected Evidence: Collected Evidence: Change the size of the main body of a trawl net One study examined the effects of changing the size of the main body of a trawl net to reduce unwanted catch on marine fish populations. The study was in the North Sea (Norway). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (1 STUDY) Improved size-selectivity of fishing gear (1 study): One replicated study in the North Sea found that reducing the size of the main body of a trawl net did not improve the size-selection of cod and haddock. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2705https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2705Thu, 17 Dec 2020 12:05:11 +0000Collected Evidence: Collected Evidence: Modify a bottom trawl to raise parts of the gear off the seabed during fishing Two studies examined the effects of modifying a bottom trawl to raise parts of the gear off the seabed during fishing on marine fish populations. One study was in the Gulf of Carpentaria (Australia) and one was in the Atlantic Ocean (USA). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (2 STUDIES) Reduction of unwanted catch (2 studies): Two replicated studies (one randomized and both controlled) in the Gulf of Carpentaria and the Atlantic Ocean found that bottom trawls with parts of the gear raised off the seabed caught fewer unwanted sharks, other elasmobranchs and fish and fewer of three of seven unwanted fish species compared to conventional trawls. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2708https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2708Mon, 28 Dec 2020 15:51:05 +0000Collected Evidence: Collected Evidence: Modify design or arrangement of tickler chains/chain mats in a bottom trawl Two studies examined the effects of modifying the design or arrangement of tickler chains in a bottom trawl on marine fish populations. One was in the North Sea (Netherlands/UK) and one was in the Atlantic Ocean (Scotland). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (2 STUDIES) Reduction of unwanted catch (2 studies): One of two replicated, paired, controlled studies in the North Sea and Atlantic Ocean found that removing the tickler chain from a trawl reduced catches of non-commercial target skates/rays and sharks, and individuals were larger, compared to trawling with the chain. The study also found that catches of commercial target species were typically unaffected. The other study found that two modified tickler chain arrangements did not reduce discarded fish catch compared to a standard arrangement. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2709https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2709Mon, 28 Dec 2020 15:58:06 +0000Collected Evidence: Collected Evidence: Use a separator trawl Two studies examined the effect of using a separator trawl on marine fish populations. One study was in the North Sea (UK) and the other in the Atlantic Ocean (Portugal). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (2 STUDIES) Reduction of unwanted catch (2 studies): One replicated, randomized study in the North Sea found that a separator trawl separated unwanted cod from target fish species into the lower codend, where a larger mesh size allowed more unwanted smaller cod to escape capture. One replicated study in the Atlantic Ocean found that a separator trawl fitted with a square-mesh escape panel caught less of one of two unwanted fish species in a crustacean fishery. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2711https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2711Tue, 29 Dec 2020 16:27:31 +0000Collected Evidence: Collected Evidence: Use netting of contrasting colour in a trawl net One study examined the effect of using netting of contrasting colour in a trawl net on marine fish populations. The study was in the Baltic Sea (Denmark). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (1 STUDY) Reduction of unwanted catch (1 study): One replicated, paired, controlled study in the Baltic Sea found that a trawl codend with contrasting black netting used in conjunction with a square mesh escape panel caught a similar amount of undersized cod as a conventional codend. Improved size-selectivity of fishing gear (1 study): One replicated, paired, controlled study in the Baltic Sea found that two designs of contrasting netting colour in trawl codends with square mesh escape windows did not improve the size-selectivity of cod compared to conventional codend netting colour. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2718https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2718Tue, 05 Jan 2021 15:46:48 +0000Collected Evidence: Collected Evidence: Fit rigid (as opposed to mesh) escape panels/windows to a trawl net One study examined the effects of fitting rigid escape windows/panels to trawls for fish escape on marine fish populations. The study was in the Baltic Sea. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (1 STUDY) Reduction of unwanted catch (1 study): One replicated, paired, controlled study in the Baltic Sea found that fitting rigid escape windows in a section of trawl net reduced the catch of unwanted flatfish compared to a trawl net without escape windows. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2719https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2719Tue, 05 Jan 2021 15:50:35 +0000Collected Evidence: Collected Evidence: Fit mesh escape panels/windows to a trawl net and use square mesh instead of diamond mesh codend One study examined the effects of fitting mesh escape panels to a trawl net and using a square mesh instead of a diamond mesh codend on marine fish populations. The study was in the English Channel (UK). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (1 STUDY) Reduction of unwanted catch (1 study): One replicated, paired, controlled study in the English Channel found that using a trawl net with square mesh escape panels and a square mesh codend reduced the numbers of discarded finfish compared to a diamond mesh codend with no panels. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2724https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2724Thu, 21 Jan 2021 16:56:46 +0000Collected Evidence: Collected Evidence: Fit a size-sorting escape grid (rigid or flexible) to trawl nets and use a square mesh instead of a diamond mesh codend Three studies examined the effects of fitting a size-sorting escape grid (rigid or flexible) to trawl nets and using a square mesh instead of a diamond mesh codend on marine fish populations. The studies were in the North Sea (UK), the Kattegat and Skagerrak (Sweden/Denmark) and the Coral Sea (Australia). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR RESPONSE (0 STUDIES) OTHER (3 STUDIES) Reduction of unwanted catch (3 studies): Three replicated, paired, controlled studies (one randomized) in the North Sea, Kattegat and Skagerrak and Coral Sea found that trawl nets with an escape grid and a square mesh codend caught fewer unwanted whiting, plaice, cod, haddock and unwanted catch of the most frequently caught fish species, but not hake or less frequently caught species compared to a diamond mesh codend with no grid. One also found that catch rates of most fish species were similar compared to a square mesh codend alone. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2725https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2725Thu, 21 Jan 2021 16:59:21 +0000Collected Evidence: Collected Evidence: Fit a moving device to a trawl net to stimulate fish escape response (stimulator device) Three studies examined the effects of fitting a moving device to a trawl net to stimulate fish escape response (stimulator device) on marine fish populations. Two studies were conducted in laboratory facilities (South Korea) and one study was in the Baltic Sea (Northern Europe). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (3 STUDIES) Reduction of unwanted catch (2 studies): Two replicated, controlled studies in a laboratory found that trawl nets fitted with moving devices to stimulate fish escape response increased the escape of young red seabream compared to without devices, but for young olive flounder moving devices were only effective at increasing escape when used in combination with another novel device that made the net shake. Improved size-selectivity of fishing gear (1 study): One replicated, controlled study in the Baltic Sea found that only one of three types of moving stimulator devices fitted in conjunction with square mesh escape panels improved the size selectivity for cod, compared to without devices. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2729https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2729Tue, 26 Jan 2021 14:04:39 +0000