Collected Evidence: Collected Evidence: Establish long-term fishery closures Five studies examined the effects of establishing long-term fishery closures in an area on marine fish populations. One study was in each of the Norwegian Sea (Norway), the North Sea (UK), the Gulf of Maine (USA), the Bismark Sea (Papua New Guinea) and the Kattegat (Sweden/Denmark). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (4 STUDIES) Condition (2 studies): One replicated, before-and-after study in the Norwegian Sea found that in the five years after the long-term closure of a commercial coastal fishery, the weights of young salmon returning to rivers were higher than before, and weights of older salmon were similar or lower. One site comparison study in the Gulf of Maine found that there were smaller, but similar condition monkfish inside an area closed year-round to groundfish fishing for six to seven years than an area open to all fishing. Abundance (4 studies): Two site comparison studies in the Gulf of Maine and Bismark Sea found a higher abundance of only one of seven fish species and lower abundance of monkfish in areas closed to groundfish (bottom-dwelling) fisheries for six to eight years, compared to open areas. One of two replicated, before-and-after studies (one controlled) in the Norwegian Sea and North Sea found that there were more young salmon and similar numbers of older salmon returning to rivers than before, in the five years after the long-term closure of a commercial coastal fishery. The other study found that lesser sandeel biomass and density peaked but there was no overall increase in the three years after a long-term fishery closure compared to before. BEHAVIOUR (1 STUDY) Behaviour change (1 study): One site comparison study in the Bismark Sea found that in an area closed to customary fishing for eight years, six of seven fish species had a lower flight response distance compared to an area open to customary fishing, making them more vulnerable to capture with spear guns. OTHER (3 STUDIES) Reduction of unwanted catch (1 study): One replicated, before-and-after study in the Kattegat found that a combination of long-term fishery closures and areas limited to specific gears reduced unwanted catch of cod compared to before. Reduction of fishing effort (1 study): One replicated, controlled, before-and-after study in the North Sea found that long-term closure of a commercial fishery reduced overall fishing effort for lesser sandeel. Commercial catch abundance (1 study): One replicated, controlled, before-and-after study in the North Sea found that annual sandeel catch rates were varied after the indefinite closure of the commercial fishery in an area. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2655https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2655Thu, 12 Nov 2020 14:53:37 +0000Collected Evidence: Collected Evidence: Establish temporary fishery closures Five studies examined the effects of establishing temporary fishery closures on marine fish populations. Two studies were in the North Atlantic Ocean (Canada, UK) and one study was in each of the North Sea (UK), the Philippine Sea (Palau) and the Mediterranean Sea (Spain).  COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Abundance (1 study): One before-and-after, site comparison study in the Atlantic Ocean found no increase in the biomass of the spawning stock of cod following a temporary fishery closure compared to fished areas over nine years. Survival (1 study): One before-and-after, site comparison study in the Atlantic Ocean found no change in the survival of cod following a temporary fishery closure compared to fished areas over nine years. Condition (1 study): One before-and-after, site comparison study in the Atlantic Ocean found no change in the length composition of cod following a temporary fishery closure, compared to fished areas over nine years. BEHAVIOUR (1 STUDY) Use (1 study): A study in the Northeast Atlantic Ocean reported that over five years tagged adult cod spent nearly a third of time inside a seasonally closed cod spawning area during implementation, and were thus given increased protection from any gears targeting bottom-dwelling fish during the spawning period. OTHER (4 STUDIES) Reduction of fishing effort (1 study): One replicated, controlled, before-and-after study in the North Sea found that fixed temporary closures had little effect on fishing effort for cod, but real-time area closures reduced the annual amount of cod caught (retained and discarded). Commercial catch abundance (3 studies): One of two replicated (one controlled, one before-and-after) studies in the Philippine Sea and Mediterranean Sea found that during a temporary closure of a grouper fishery, spear fisher catch numbers of other fish groups (herbivores) increased, indicating they were being targeted more compared to the open season. The other study found that in targeted fisheries over 10 years, catch rates of red mullet and total catch (fish and invertebrates combined), but not European hake, increased after temporary closures, compared to before. One before-and-after, site comparison study in the Atlantic Ocean found no change over nine years in cod catches following a temporary fishery closure compared to fished areas. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2664https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2664Wed, 18 Nov 2020 16:03:49 +0000Collected Evidence: Collected Evidence: Cease or prohibit spearfishing Five studies examined the effects of ceasing or prohibiting spearfishing in an area on marine fish populations. Two studies were in the Mediterranean Sea (France, Corsica). One study was in each of the Tasman Sea (Australia) and the Indian Ocean (South Africa). One study was a review of marine reserves around the world. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (4 STUDIES) Abundance (4 studies): Two of three site comparison studies in the Mediterranean Sea, the Tasman Sea and the Indian Ocean found that prohibiting spearfishing, and line fishing, in protected areas increased the abundances of European seabass and gilthead seabream (years unknown) and of coral reef fish species, compared to protected and unprotected fished areas, after two to seven years. The other study found that fish densities differed between spearfished and non-spearfished areas after 10–12 years, and was affected by depth and/or fish size. A review of reef marine reserves around the world reported that two non-spearfished reserves in the northwestern Atlantic had more snappers and grunts after two years in one, and higher densities of reef fish, including snappers and grunts after 20 years in the other, compared to nearby fished reefs. Condition (3 studies): Two site comparison studies in the Mediterranean Sea and the Indian Ocean found that prohibiting spearfishing (and linefishing) in marine protected areas resulted in larger European seabass and coral reef fish species, compared to protected and unprotected fished areas, after two to seven years. A review of global reef marine reserves reported that reef fish were larger in one reserve in the northwestern Atlantic that had banned spearfishing for 20 years, compared to nearby fished reefs. BEHAVIOUR (0 STUDIES) OTHER (1 STUDY)  Commercial catch abundance (1 study): One replicated, site-comparison study in the Mediterranean Sea found that prohibiting spearfishing in specific zones of a marine reserve resulted in higher commercial and recreational fishery catches of targeted common dentex compared to zones that allowed spearfishing and areas outside the reserve after one to three years.    Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2672https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2672Fri, 20 Nov 2020 09:32:23 +0000Collected Evidence: Collected Evidence: Cease or prohibit all fishing activity in a marine protected area with limited exceptions Four studies examined the effects of ceasing or prohibiting all fishing activity in a marine protected area with limited exceptions on marine fish populations. One study was in each of the Pacific Ocean (USA), the Caribbean Sea (US Virgin Islands), the Great Barrier Reef (Australia) and the Skagerrak (Norway). COMMUNITY RESPONSE (1 STUDY) Richness/diversity (1 study): One site comparison study in the Caribbean Sea found that in marine protected areas closed to all fishing with limited exceptions for up to seven years, there was lower total fish species richness compared to unprotected areas. POPULATION RESPONSE (3 STUDIES) Abundance (2 studies): One replicated, site comparison study in the Pacific Ocean found that abundance of copper rockfish, quillback rockfish, china rockfish and lingcod was similar between non-voluntary and voluntary ‘no-take’ reserve sites where all fishing with limited exceptions had been prohibited for one to eight years, and sites open to fishing. One site comparison study in the Caribbean Sea found that restricting all fishing activity except for bait fishing in marine protected areas for seven years resulted in similar total fish biomass and lower total fish density, compared to unprotected areas. Survival (1 study): One replicated, controlled, before-and-after study in the Skagerrak found that cod survival increased inside a marine protected area in the eight years after almost all fishing was prohibited, compared to outside areas fished with a wider range of gear types. BEHAVIOUR (1 STUDY) Use (1 study): One replicated study in the Great Barrier Reef found that immature pigeye sharks and adult spottail sharks were detected frequently and over long time periods inside marine protected areas five years after prohibiting almost all fishing except restricted line fishing and bait netting, thus reducing the overall likelihood of fishing mortality. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2681https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2681Fri, 27 Nov 2020 16:53:17 +0000Collected Evidence: Collected Evidence: Deploy fishing gear at selected depths to avoid unwanted species Five studies examined the effect of deploying fishing gear at selected depths to avoid unwanted species on marine fish populations. Three studies were in the Atlantic Ocean (Florida, Brazil, Canary Islands), and one study was in each of the Pacific Ocean (Hawaii) and the Tasman Sea (Australia). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (5 STUDIES) Reduction of unwanted catch (5 studies): Four of five replicated studies (three controlled, one paired and controlled) in the Pacific Ocean, Atlantic Ocean and the Tasman Sea found that deploying fishing gear (longlines, handlines and traps) at selected depths, including above the seabed instead of on it, reduced the unwanted catches of five of 17 fish species, three of eight shark/ray species, non-commercially targeted fish species and Harrison’s dogfish, compared to depths usually fished. The other study found that different shark species were hooked at different depths in the water column during bottom-set longlining deployments.Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2683https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2683Mon, 30 Nov 2020 16:26:13 +0000Collected Evidence: Collected Evidence: Reduce duration of fishing gear deployments Four studies examined the effects of reducing the duration of time that fishing gear is deployed in the water on marine fish populations. Two studies were in the North Sea. One study was in the Atlantic Ocean (USA) and one was in both the Barents Sea and Atlantic Ocean (Norway/USA).  COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (2 STUDIES)  Survival (2 studies): Two replicated, controlled studies in the North Sea found that survival of unwanted plaice and/or sole released after capture in beam or pulse trawls was higher after shorter duration trawl deployments, but that the opposite was true for plaice captured in otter trawls, over tow durations of between one and two hours.  BEHAVIOUR (0 STUDIES) OTHER (2 STUDIES)  Reduction of unwanted catch (1 study): One of two replicated studies (one paired and controlled) in the Barents Sea/Atlantic Ocean and the Atlantic Ocean found that catch rates of unwanted sharks caught in longline gear decreased with decreasing time the gear was deployed in the water, over durations of up to 10 hours. The other study found that shorter tow durations caught similar amounts of small haddock, but more small cod, than longer durations, in bottom trawls fished for between five minutes and one hour. Improved size-selectivity of fishing gear (1 study): One replicated, paired, controlled study in the Barents Sea/Atlantic Ocean found that varying bottom trawl fishing durations between five minutes and two hours had no effect on the size-selectivity of Atlantic cod, haddock or long rough dab. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2686https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2686Mon, 30 Nov 2020 17:00:02 +0000Collected Evidence: Collected Evidence: Reduce the duration of exposure to air of captured fish before release Three studies examined the effect of reducing the duration of exposure of fish to air on marine fish populations. One study was in each of the Bay of Biscay (Spain), Gulf of Alaska (Canada) and Coral Sea (Australia).  COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (2 STUDIES) Survival (1 study): One replicated study in the Bay of Biscay found that reducing air exposure before release did not increase the survival of small-spotted catshark caught during commercial trawling. Condition (1 study): One replicated study in the Gulf of Alaska found that shorter durations of air exposure before release improved the physical condition and reduced the amount of injury to discarded chum salmon caught in purse seine nets.  BEHAVIOUR (1 STUDY) Behaviour change (1 study): One study in the Coral Sea found that minimal exposure to air and handling resulted in improved overall behaviour after release (activity and ability to return to reef) of reef fish, compared to fish exposed to air and handling for longer duration. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2690https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2690Wed, 02 Dec 2020 14:47:25 +0000Collected Evidence: Collected Evidence: Release protected or species of concern alive after capture Six studies examined the effects of releasing protected or species of concern alive after capture on marine fish populations. Two studies were in the Atlantic Ocean (USA and Canada), and one was in each of the Coral Sea (Australia), Tasman Sea (New Zealand), Cantabrian Sea (Spain) and the Pacific Ocean (USA).  COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (6 STUDIES) Survival (6 studies): Four of six replicated studies in the Atlantic Ocean, Tasman Sea, Cantabrian Sea and the Pacific Ocean found that the majority (76–92%) of unwanted (discarded or protected) small-spotted catshark, thorny skate, pearl perch and Atlantic wolffish, but less than half of smooth skate, survived for at least 1 h–5 days after capture and/or release, and survival was reduced by hooking/capture depth injuries and longer tow durations. One study found that nearly all yelloweye rockfish survived for four days after capture and release, but canary rockfish survival decreased with increasing capture depth. The other study found that all spinetail devilrays brailed aboard from purse seine nets survived but not those brought aboard entangled in the net. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2691https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2691Wed, 02 Dec 2020 14:55:19 +0000Collected Evidence: Collected Evidence: Modify longline configuration Four studies examined the effects of modifying longline configuration on marine fish populations. One study was in each of the Norwegian Sea (Norway) and Atlantic Ocean (Brazil). Two were global reviews.  COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (2 STUDIES) Survival (2 studies): One global review found that survival of unwanted sharks and rays at retrieval of longline gear was higher on nylon hook attachment lines instead of wire for two of three species and lower for one. One replicated, controlled study in the Atlantic Ocean found that survival of unwanted sharks caught on tuna longlines was reduced with nylon hook lines compared to wire. BEHAVIOUR RESPONSE (0 STUDIES) OTHER (4 STUDIES) Reduction of unwanted catch (4 studies): One of two replicated, controlled studies in the Norwegian Sea and Atlantic Ocean and one of two reviews of worldwide longline fisheries found that modifying longline configuration (increasing the lead weight on mid-water longlines to increase the sinking rate or using nylon instead of wire hook attachments) reduced the catches of unwanted sharks and/or rays compared to standard longlines. One review found that longline modifications reduced unwanted shark/ray catches in one of two cases. The other study found that modified longlines did not reduce catches of undersized haddock compared to standard longlines. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2699https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2699Wed, 09 Dec 2020 16:42:33 +0000Collected Evidence: Collected Evidence: Modify gillnet or entangling (trammel/tangle) net configuration Four studies examined the effects of modifying gillnet or entangling (trammel or tangle) net configuration on marine fish populations. One study was in each of the Gulf of Maine (USA), the Atlantic Ocean (USA) and the Adriatic Sea (Italy), and one study was in two estuaries in North Carolina (USA).  COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (4 STUDIES) Reduction in unwanted catch (4 studies): Three of four replicated studies (one controlled, two paired and controlled) in the Gulf of Maine, Atlantic Ocean, Adriatic Sea and estuaries in the USA, found that modifications to the configuration of gillnets, including reduced height, increased tension twine diameter and mesh size and orientation, reduced the unwanted catch of cod in one of two net designs, discarded fish of commercial and non-commercial species, and the discards of non-commercial, but not commercial species (fish and invertebrates), compared to conventional configurations. The other study found that gillnet modification did not typically reduce unwanted shark catches compared to unmodified gillnets. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2701https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2701Fri, 11 Dec 2020 11:55:00 +0000Collected Evidence: Collected Evidence: Fit escape devices (panels/grids) to encircling nets Three studies examined the effect of fitting fish escape devices (panels or size-sorting grids) to encircling nets on marine fish populations. One study was in the Tasman Sea (Australia), one was in the North and Norwegian Seas (Norway) and one was in the Atlantic Ocean (Portugal).  COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Survival (1 study): One replicated, controlled study in the North and Norwegian Seas reported no difference in the survival of saithe, but reduced survival of mackerel, between fish that had passed through a rigid size-sorting escape grid in a purse seine net and those that had not, after one month. BEHAVIOUR (0 STUDIES) OTHER (2 STUDIES) Reduction of unwanted catch (2 studies): Two replicated studies (one controlled) in the Tasman Sea and Atlantic Ocean found that transparent panels of net and a large-diamond mesh escape panel fitted to fish seine nets, reduced the catches of unwanted small individuals of one of four commercially targeted fish and unwanted or undersized fish, compared to conventional seine nets. Improved size-selectivity of fishing gear (1 study): One replicated, controlled study in the Tasman Sea found that size-selectivity of one of four commercial fish species was improved in seine nets with transparent netting panels compared to without. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2703https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2703Mon, 14 Dec 2020 14:09:11 +0000Collected Evidence: Collected Evidence: Modify the design or configuration of trawl doors Three studies examined the effects of modifying the design or configuration of trawl doors on marine fish populations. One study was in the Tasman Sea, one in the Clarence Estuary and one in Lake Wooloweyah (all in Australia).  COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (3 STUDIES) Reduction in unwanted catch (3 studies): Three replicated, controlled studies (one paired) in the Tasman Sea, the Clarence Estuary and Lake Wooloweyah found that modified or different designs of trawl doors caught similar amounts of unwanted fish overall, compared to conventional door types. However, one study found fewer of one of five individual unwanted fish species were caught with modified doors. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2707https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2707Mon, 28 Dec 2020 15:41:41 +0000Collected Evidence: Collected Evidence: Use a different twine type in a trawl net Five studies examined the effects of using a different twine type in a trawl net on marine fish populations. Two studies were in each of the North Sea (UK) and the Western Baltic Sea (Denmark/Germany), and one study was in the Adriatic Sea (Italy). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (5 STUDIES) Improved size-selectivity of fishing gear (5 studies): Four of five replicated studies (four controlled) in the North Sea, Baltic Sea and Adriatic Sea found that using a different twine type (twine thickness and construction material) improved the size-selectivity of bottom fish, haddock, Atlantic cod, plaice and flounder, compared to thinner or other twine materials. One study found that selectivity of non-target haddock and plaice was similar for three different twine diameters. One of these studies also found that size-selectivity of fish was influenced by twine number and mesh orientation, while another found no effect of twine number and mesh orientation, but cod selectivity increased with a smaller codend circumference. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2710https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2710Tue, 29 Dec 2020 16:07:09 +0000Collected Evidence: Collected Evidence: Use a topless (coverless) trawl Four studies examined the effect of using a topless or coverless trawl on marine fish populations. Two studies were in the North Sea (UK, Norway, Sweden), one study was in the Gulf of Maine (USA) and one study was in the North Sea, Skagerrak and the Baltic Sea (Northern Europe).  COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (4 STUDIES) Reduction of unwanted catch (4 studies): Two of four replicated, controlled studies (three paired) in the North Sea, Gulf of Maine, and North Sea, Skagerrak and Baltic Sea found that using a topless trawl, in one case in combination with another non-conventional trawl type, reduced the catch of unwanted Atlantic cod and discards of commercial fish species compared to conventional trawl types. One study found that topless trawls reduced unwanted catches of larger but not smaller haddock and larger Atlantic cod only in one of two cases, compared to standard trawl types. The other study found that discarded catches of one of four commercial fish species were reduced in topless trawls. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2712https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2712Tue, 29 Dec 2020 16:31:56 +0000Collected Evidence: Collected Evidence: Use an electric (pulse) trawl Three studies examined the effects of using an electric (pulse) trawl on marine fish populations. The studies were in the North Sea (Belgium, Netherlands and multiple European countries).  COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR RESPONSE (0 STUDIES) OTHER (3 STUDIES) Reduction of unwanted catch (3 studies): Two replicated, paired, controlled studies and one review in the North Sea found that using an electric/pulse trawl reduced the catches of non-target or undersized (discarded) commercial fish in some or all cases, compared to using a standard trawl. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2713https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2713Tue, 29 Dec 2020 16:45:07 +0000Collected Evidence: Collected Evidence: Rotate the orientation of diamond mesh in a trawl net Six studies examined the effects of rotating the orientation of diamond mesh in a trawl net on marine fish populations. Three studies were in the Baltic Sea (Denmark), and one study was in each of the Kattegat and Skagerrak (northern Europe), the Aegean Sea (Turkey) and the North Sea (Belgium/UK).  COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (6 STUDIES) Improved size-selectivity of fishing gear (6 studies): One review study in the Kattegat and Skagerrak and four of five replicated, controlled studies (one paired) in the Baltic Sea, Aegean Sea, and North Sea found that turning the orientation of diamond mesh in trawl codends by 90° resulted in better size selection of cod, red mullet and common pandora, and round-bodied fish species, but not of plaice, annular sea bream, and flatfish species, compared to standard orientation of diamond mesh in trawl codends. The other study found that turned mesh instead of standard diamond mesh trawl codends did not improve the size selectivity of cod, plaice and flounder. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2715https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2715Fri, 01 Jan 2021 16:13:18 +0000Collected Evidence: Collected Evidence: Fit a size-sorting mesh funnel (a sieve net) to a prawn/shrimp trawl net Three studies examined the effects of fitting a size-sorting mesh funnel (sieve net) to a prawn/shrimp trawl net on marine fish populations. All three studies were in the North Sea (Belgium, UK). 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 in the North Sea found that shrimp trawls fitted with a mesh size-sorting funnel, a sieve net, reduced the catches of unwanted (non-commercial or discarded) fish, compared to standard trawls. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2722https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2722Wed, 20 Jan 2021 12:16:50 +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%2Fconservationevidencejournal.com%2Factions%2F2725https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2725Thu, 21 Jan 2021 16:59:21 +0000Collected Evidence: Collected Evidence: Fit a size-sorting escape grid (rigid or flexible) and large, supported escape openings to trawl nets Four studies examined the effect of fitting trawl nets with a size-sorting escape grid and large, supported escape openings for fish escape on marine fish populations. Two studies were in the Gulf of Carpentaria (Australia), one study was in the Atlantic Ocean (USA) and one study was in the Persian Gulf (Iran).  COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (4 STUDIES) Reduction of unwanted catch (4 studies): Three of four replicated studies (three paired and controlled) in the Gulf of Carpentaria, the Atlantic Ocean and the Persian Gulf, found that trawl nets fitted with a both a size-sorting escape grid and a large supported escape opening reduced the catches of unwanted fish and sharks and rays, but not sawfish, compared to standard trawl nets. The other study found that trawl nets with an escape grid/opening caught similar amounts of unwanted sharks to trawl nets without. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2726https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2726Fri, 22 Jan 2021 13:26:19 +0000Collected Evidence: Collected Evidence: Fit mesh escape panels/windows and a size-sorting grid (rigid or flexible) to a trawl net Six studies examined the effects of fitting trawl nets with mesh escape panels or windows and a size-sorting grid on marine fish populations. Two studies were in the Atlantic Ocean (Portugal, Suriname), two were in the Indian Ocean (Australia, Mozambique), one study was in the Gulf of Carpentaria (Australia) and one was in the English Channel (UK).  COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (6 STUDIES) Reduce unwanted catch (5 studies): Four of five replicated studies (four paired, controlled) in the Gulf of Carpentaria, Indian Ocean and Atlantic Ocean, found that bottom trawl nets fitted with square mesh escape panels and size-sorting grids of various types reduced the unwanted catch (non-target or undersized) of fish, sharks and stingrays, rays and total discarded catch (fish and invertebrates), compared to standard unmodified trawl nets, and that fish escape through either the panel/window, grid, or both varied between fish species or sizes. The other study found that the escape of non-target fish from the combined use of a square mesh panel and grid depended on the position of the panel in the net. Improved size-selectivity of fishing gear (1 study): One replicated, paired, controlled study in the English Channel found that size-selectivity of whiting was increased in bottom trawl nets fitted with square mesh escape panels or cylinders in combination with one or two size-sorting grids of different types, compared to standard nets. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2727https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2727Fri, 22 Jan 2021 15:52:49 +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%2Fconservationevidencejournal.com%2Factions%2F2729https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2729Tue, 26 Jan 2021 14:04:39 +0000Collected Evidence: Collected Evidence: Use hook and line fishing instead of other commercial fishing methods Three studies examined the effects of using hook and line fishing instead of other commercial fishing methods on marine fish populations. One study was in each of the Tasman Sea (Australia), the Atlantic Ocean (Canada) and the Gulf of St. Lawrence (Canada).  COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Survival (1 study): One replicated, controlled study in the Gulf of St. Lawrence found that fish caught by hook and line methods had greater vitality (an indicator of post-release survival) than fish caught by other gear types. BEHAVIOUR (0 STUDIES) OTHER (2 STUDIES) Reduction of unwanted catch (1 study): One replicated, controlled study in the Tasman Sea found that using longlines reduced the capture of unwanted small snapper, compared to trawling. Improved size-selectivity of fishing gear (1 study): One replicated, paired, controlled study in the Atlantic Ocean found that longlining compared to trawling, increased the size selectivity of cod and haddock at larger hook sizes only. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2732https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2732Thu, 28 Jan 2021 11:49:50 +0000Collected Evidence: Collected Evidence: Set a minimum landing size for commercially fished species Five studies examined the effects of setting a minimum landing size for commercially fished species on marine fish populations. One study was a global review and one study was in each of the Tasman Sea (Australia), the Baltic Sea (Northern Europe), the Ionian Sea (Greece) and the Northwest Atlantic Ocean (USA). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (2 STUDIES) Reproductive success (2 studies): One global review reported that one of five swordfish fisheries showed an increase in swordfish recruitment after the setting of recommended minimum landing sizes and catch limits, with recruitment in the other fisheries either highly variable or unable to be assessed. One replicated study in the Ionian Sea reported that, despite established minimum sizes, most fish landed in commercial catches were immature, and thus had never spawned. BEHAVIOUR (0 STUDIES) OTHER (3 STUDIES) Reduction of unwanted catch (3 studies): One of three before-and-after studies (one replicated) in the Atlantic Ocean, Tasman Sea and Baltic Sea found that following an increase in the set minimum landing size and mesh size of gill nets the catches of the youngest southern flounder were reduced. The other two found that increasing the minimum landing size did not reduce the catches of discarded dusky flathead and Atlantic cod3, and discarding of flathead increased in one of three cases. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2735https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2735Tue, 02 Feb 2021 14:28:08 +0000Collected Evidence: Collected Evidence: Involve fishers and stakeholders in co-management Three studies examined the effect of involving fishers and stakeholders in co-management on marine fish populations. One study was in each of the Indian Ocean, the South China Sea (Vietnam) and the Pacific Ocean (Tonga).  COMMUNITY RESPONSE (1 STUDIES) POPULATION RESPONSE (1 STUDY) Abundance (1 study): One before-and-after study the Indian Ocean found that involving fishers and stakeholders in co-management increased overall fish abundance, but abundance varied between species groups, nine years after implementation compared to before. BEHAVIOUR (0 STUDIES) OTHER (2 STUDIES) Reduction of fishing effort (1 study): One before-and-after study in the Pacific Ocean found that in the five years after implementation of a new co-management system there was no decrease in overall fishing effort in the managed area. Commercial catch abundance (1 study): One before-and-after study in the Pacific Ocean found no increase in total fish catch rates and a decrease in catch rates of half of the six species groups individually inside an area with a new co-management system after five years. Improved compliance/reduction of illegal fishing activity (1 study): One before-and-after study in the South China Sea reported that after co-management was established in an area there was a decrease in illegal fishing using destructive fishing gears. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2910https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2910Mon, 08 Feb 2021 16:20:11 +0000Collected Evidence: Collected Evidence: Protect spawning fish from capture Four studies examined the effects of protecting spawning fish on marine fish populations. Two studies were in the North Atlantic Ocean (Canada, UK) and one study was in each of the Philippine Sea (Palau) and the Tasman Sea (Australia).  COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Abundance (1 study): One before-and-after, site comparison study in the Atlantic Ocean found no increase in the biomass of the spawning stock of Atlantic cod in the nine years following implementation of a seasonal fishery closure to protect spawning cod, compared to fished areas. Survival (1 study): One before-and-after, site comparison study in the Atlantic Ocean found no change in Atlantic cod survival in the nine years after a seasonal fishery closure to protect spawning cod was implemented, compared to fished areas. Condition (1 study): One before-and-after, site comparison study in the Atlantic Ocean found no change in the length composition of Atlantic cod in the nine years following a seasonal fishery closure to protect spawning cod, compared to fished areas. BEHAVIOUR (2 STUDIES) Use (2 studies): One site comparison study and one study in the Northeast Atlantic Ocean and Tasman Sea reported that spawning and/or nursery areas closed seasonally or permanently to fishing were used by tagged adult Atlantic cod for nearly a third of time during spawning, and by school sharks less than one year old for up to 80% of time, but by school sharks between one and two years old for 18% of time, compared to areas outside. OTHER (2 STUDIES) Commercial catch abundance (2 studies): One before-and-after, site comparison study in the Atlantic Ocean found no change over nine years in commercial catches of Atlantic cod following a seasonal fishery closure to protect spawning cod compared to fished areas. One replicated, controlled study in the Philippine Sea found that during seasonal closure of a grouper fishery to protect spawning individuals, the commercial catch numbers of other fish groups (herbivores) increased, indicating they were being targeted more by spear fishers compared to the open season. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2938https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2938Thu, 11 Feb 2021 16:13:52 +0000
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What Works in Conservation

What Works in Conservation provides expert assessments of the effectiveness of actions, based on summarised evidence, in synopses. Subjects covered so far include amphibians, birds, mammals, forests, peatland and control of freshwater invasive species. More are in progress.

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