Collected Evidence: Collected Evidence: Restrict fishing activity (types unspecified) in a marine protected area Two studies examined the effects of restricting (unspecified) fishing activity in a marine protected area on marine fish populations. One study was global and the other was in the Indian Ocean (Tanzania).  COMMUNITY RESPONSE (1 STUDY) Richness/diversity (1 study): One global review reported that of 11 studies showing effects of protection from restricting fishing activity in marine reserves, one found higher fish species richness inside reserves compared to non-protected fished areas. POPULATION RESPONSE (2 STUDIES) Survival (1 study): One site comparison study in the Indian Ocean found that survival was higher for blackspot snapper inside a marine park with unspecified fishing restrictions and low fishing intensity compared to more intensively fished areas outside. Abundance (1 study): One global review reported that 10 of 11 studies showing effects of protection from restricting fishing activity in marine reserves found higher abundance of fish inside the areas compared to areas without fishing restrictions. Condition (2 studies): One site comparison study in the Indian Ocean found that blackspot snapper inside a marine park with unspecified fishing restrictions and low fishing intensity were of larger average size, reached older ages, but did not have different growth rates compared to more intensively fished areas outside the park. One global review reported that five out of 11 studies showing effects of protection from restricting fishing activity in marine reserves found fish were larger inside reserves compared to non-protected areas without fishing restrictions. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2680https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2680Fri, 27 Nov 2020 16:25:54 +0000Collected Evidence: Collected Evidence: Selectively avoid unwanted fish based on temperature distribution We found no studies that evaluated the effects of selectively avoiding fish by their temperature distributions on marine fish populations. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this intervention during our systematic journal and report searches. Therefore, we have no evidence to indicate whether or not the intervention has any desirable or harmful effects.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2685https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2685Mon, 30 Nov 2020 16:56:00 +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%2Fwww.conservationevidence.com%2Factions%2F2686https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2686Mon, 30 Nov 2020 17:00:02 +0000Collected Evidence: Collected Evidence: Reduce the hauling speed of a trawl net We found no studies that evaluated the effects of reducing the hauling speed of a trawl net on marine fish populations.  ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this intervention during our systematic journal and report searches. Therefore, we have no evidence to indicate whether or not the intervention has any desirable or harmful effects.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2688https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2688Wed, 02 Dec 2020 10:47:28 +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%2Fwww.conservationevidence.com%2Factions%2F2690https%3A%2F%2Fwww.conservationevidence.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%2Fwww.conservationevidence.com%2Factions%2F2691https%3A%2F%2Fwww.conservationevidence.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%2Fwww.conservationevidence.com%2Factions%2F2699https%3A%2F%2Fwww.conservationevidence.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%2Fwww.conservationevidence.com%2Factions%2F2701https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2701Fri, 11 Dec 2020 11:55:00 +0000Collected Evidence: Collected Evidence: Modify fishing trap/pot configuration Twenty-three studies examined the effects of modifying fishing trap or pot configuration on marine fish populations. Five studies were in the Atlantic Ocean (USA, Brazil, Canary Islands, Canada). Three studies were in each of the Bothnian Sea (Sweden), the Baltic Sea (Poland, Sweden), the Tasman Sea (Australia) and the Indian Ocean (Kenya, South Africa). One study was in each of the Kattegat (Denmark), the Mediterranean Sea (Spain), the Adriatic Sea (Italy), the Southern Ocean (Australia), the Pacific Ocean (Canada) and the Barents Sea (Norway).  COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Survival (1 study): One replicated, controlled study in the Bothnian Sea found that survival of small herring escaped from a pontoon fish trap through a size-sorting grid was similar to trap-caught herring that did not pass through a grid. BEHAVIOUR (0 STUDIES) OTHER (22 STUDIES) Reduction of unwanted catch (20 studies): Sixteen of 20 replicated studies (11 controlled, one randomized, paired and controlled, one randomized and controlled, two paired and controlled and one randomized) and one before-and-after study in the Atlantic Ocean, Baltic Sea, Mediterranean Sea, Southern Ocean, Tasman Sea, Adriatic Sea, Bothnian Sea, Indian Ocean, Pacific Ocean, the Kattegat and the Barents Sea, found that modifications to trap configuration (various, including using a different trap type, increased mesh size and fitting an escape device) reduced the unwanted (undersized, discarded or non-commercial target) catches of fish (overall, or all of multiple study species), brown trout, black sea bass, herring, bluethroat wrasse and leatherjacket, cod, protected rockfishes, whitefish, black sea bass, American eel and winter flounder, sharks/rays and of salmon and rainbow trout in one of two cases, compared to unmodified conventional traps or traps of other designs. One of these also found that the number of unwanted species (fish and invertebrates) was lower in modified traps. Three other studies, found that trap modification or type had no effect on unwanted catches of white croaker, non-commercial fish or undersized Atlantic cod, and non-target haddock catches were increased. However, one of these also reported that traps (creels) did not catch high proportions of immature fish, unlike bottom trawls. Improved size-selectivity of fishing gear (4 studies): Three of four replicated studies (two controlled and one randomized, paired and controlled) in the Baltic Sea, Tasman Sea, Indian Ocean and Atlantic Ocean found that traps or pots modified with a square mesh escape window or larger mesh sizes improved the size-selectivity of Atlantic cod, black sea bass and most fish species compared to smaller mesh and/or standard gear. The other found that increasing mesh size of a trap escape panel had no effect on size-selectivity of panga. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2702https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2702Mon, 14 Dec 2020 10:32:58 +0000Collected Evidence: Collected Evidence: Modify the design or configuration of trawl gear (mixed measures) Nineteen studies examined the effects of modifying the design or configuration of trawl gear on marine fish populations. Seven studies were in the Clarence River estuary (Australia), three studies were in each of the Mediterranean Sea (Turkey) and North Sea (UK), two studies were in the North Pacific Ocean (USA), and one study was in each of the South Pacific Ocean, the Skagerrak and Baltic Sea (Denmark/Sweden), the Atlantic Ocean (USA) and the Coral Sea (Australia).  COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (19 STUDIES) Reduce unwanted catch (16 studies): Twelve of 16 replicated studies (seven paired and controlled, five controlled, and two paired) in the Clarence River estuary, South Pacific Ocean, North Pacific Ocean, Mediterranean Sea, Skagerrak and Baltic Sea, Atlantic Ocean, North Sea and the Coral Sea, found that various modifications to trawl gear, including changes to the trawl wires, number of nets, codend number, footrope configuration, front trawl body panels, codend netting layers, spreading mechanism, method of weaving, knot orientation or using a new overall trawl design, resulted in reduced unwanted catches of non-target and/or discarded fish species or sizes, and of all sizes of four of seven commercial species, compared to standard unmodified trawl gear or other trawl designs. One of these also found increased catch rate of one commercial species and for another two species the effect varied with fish size. Two studies found that modified trawl gear reduced the unwanted catch of only a small proportion of the number of individual fish species caught compared to other trawl configurations, and also that unwanted fish catches varied between day/night. One study found that different trawl configurations had mixed effects on the numbers and sizes of non-target fish catch. The other study found no reduction in catches of discarded finfish between a modified and standard trawl codend. Improved size-selectivity of fishing gear (5 studies): Five replicated, controlled studies in the North Sea and Mediterranean Sea found that various modifications to trawl gear, including changes to the length of the extension piece, the codend strengthening bag, the method of weaving, the number of codend layers and overall design improved the size-selectivity for unwanted (non-target/discarded) fish species or sizes, and annular seabream in one of two cases, compared to unmodified standard trawl gear or other design configurations. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2704https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2704Thu, 17 Dec 2020 11:29:15 +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%2Fwww.conservationevidence.com%2Factions%2F2707https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2707Mon, 28 Dec 2020 15:41:41 +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%2Fwww.conservationevidence.com%2Factions%2F2715https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2715Fri, 01 Jan 2021 16:13:18 +0000Collected Evidence: Collected Evidence: Modify the configuration of a mesh escape panel/window in a trawl net Ten studies examined the effects of modifying the configuration (position/size and increased mesh size) of a mesh escape panel/window in a trawl net on marine fish populations. Four studies were in the Baltic Sea (Sweden/Poland). Two studies were in each of the North Sea (UK), the Irish Sea (UK) and the Kattegat and Skagerrak (Northern Europe). One study was in the Atlantic Ocean (Portugal).  COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Survival (1 study): One replicated, controlled study in the Baltic Sea found that modifying the position of a mesh escape panel in a trawl net had no effect on the survival rate of cod. BEHAVIOUR (0 STUDIES) OTHER (9 STUDIES) Reduction of unwanted catch (5 studies): Three of five replicated, paired studies (one controlled) in the Irish Sea, Atlantic Ocean and Kattegat-Skagerrak found that modifying the position or mesh size of a mesh escape panel/window in a trawl net reduced the unwanted catches of whiting in one of two cases, haddock and whiting, and boarfish, but caught similar amounts of horse mackerel and blue whiting. The other studies found that catches of unwanted cod or other fish were not reduced. Improved size-selectivity of fishing gear (4 studies): Two of four replicated, controlled studies in the North Sea and Baltic Sea found that modifying the position and/or size of a mesh escape panel in a trawl net improved size-selectivity of haddock and whiting. One of these studies also found that increasing the mesh size of the panel had no effect on size-selectivity for haddock. The other two studies found that size-selectivity was similar for cod compared to standard trawls. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2717https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2717Tue, 05 Jan 2021 14:46:39 +0000Collected Evidence: Collected Evidence: Release fish that are carrying eggs or live young We found no studies that evaluated the effects of releasing fish that are carrying eggs or live young on marine fish populations.  ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this intervention during our systematic journal and report searches. Therefore, we have no evidence to indicate whether or not the intervention has any desirable or harmful effects. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2733https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2733Tue, 02 Feb 2021 12:04:35 +0000Collected Evidence: Collected Evidence: Release males of species known to guard nests during breeding season We found no studies that evaluated the effects of releasing males that guard nests during the breeding season on marine fish populations.  ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this intervention during our systematic journal and report searches. Therefore, we have no evidence to indicate whether or not the intervention has any desirable or harmful effects. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2734https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2734Tue, 02 Feb 2021 12:09:39 +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%2Fwww.conservationevidence.com%2Factions%2F2735https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2735Tue, 02 Feb 2021 14:28:08 +0000Collected Evidence: Collected Evidence: Set a maximum landing size for commercially fished species We found no studies that evaluated the effects of setting a maximum landing size for commercially fished species on marine fish populations.  ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this intervention during our systematic journal and report searches. Therefore, we have no evidence to indicate whether or not the intervention has any desirable or harmful effects. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2736https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2736Tue, 02 Feb 2021 14:40:24 +0000Collected Evidence: Collected Evidence: Organise vessel monitoring systems We found no studies that evaluated the effects of organising monitoring systems on marine fish populations.  ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this intervention during our systematic journal and report searches. Therefore, we have no evidence to indicate whether or not the intervention has any desirable or harmful effects. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2739https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2739Tue, 02 Feb 2021 15:11:19 +0000Collected Evidence: Collected Evidence: Promote knowledge exchange between fishers to improve good practice We found no studies that evaluated the effects of promoting knowledge exchange between fishers to improve good practice on marine fish populations.  ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this intervention during our systematic journal and report searches. Therefore, we have no evidence to indicate whether or not the intervention has any desirable or harmful effects.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2814https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2814Fri, 05 Feb 2021 10:10:50 +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%2Fwww.conservationevidence.com%2Factions%2F2938https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2938Thu, 11 Feb 2021 16:13:52 +0000Collected Evidence: Collected Evidence: Prohibit certain gear types Two studies examined the effects of prohibiting certain gear types on marine fish populations. One study was in the Indian Ocean (Kenya) and one was in the Kattegat (Sweden/Denmark).   COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Abundance (1 study): One replicated, site comparison study in the Indian Ocean found that in an area where all but one gear type was prohibited there was a higher fish density compared to areas where just one gear type was prohibited and to unrestricted areas. BEHAVIOUR (0 STUDIES) OTHER (1 STUDY) Reduction of unwanted catch (1 study): One replicated, before-and-after study in the Kattegat found that a combination of areas in which non-selective gear types were prohibited and long-term fishery closures reduced unwanted catch of cod compared to before. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3810https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3810Thu, 26 May 2022 14:57:28 +0100Collected Evidence: Collected Evidence: Purchase fishing permits from fishers to limit vessel or fisher numbers We found no studies that evaluated the effects of purchasing fishing permits from fishers to limit vessel or fisher numbers on marine fish populations.   ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this intervention during our systematic journal and report searches. Therefore, we have no evidence to indicate whether or not the intervention has any desirable or harmful effects. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3818https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3818Fri, 27 May 2022 08:43:16 +0100Collected Evidence: Collected Evidence: Purchase fishing vessels from fishers to limit vessel numbers We found no studies that evaluated the effects of purchasing fishing vessels from fishers to limit vessel numbers on marine fish populations.   ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this intervention during our systematic journal and report searches. Therefore, we have no evidence to indicate whether or not the intervention has any desirable or harmful effects. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3819https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3819Fri, 27 May 2022 08:45:56 +0100Collected Evidence: Collected Evidence: Prohibit the catching and/or landing of specific fish species We found no studies that evaluated the effects of prohibiting catching and/or landing of specific species on marine fish populations.   ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this intervention during our systematic journal and report searches. Therefore, we have no evidence to indicate whether or not the intervention has any desirable or harmful effects.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3822https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3822Fri, 27 May 2022 08:51:56 +0100Collected Evidence: Collected Evidence: Prohibit high grading in which only the most profitable individuals or species are landed One study examined the effects of prohibiting high grading in which only the most profitable individuals or species are landed on marine fish populations. The study was in the North Sea/North Atlantic Ocean (UK).   COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (1 STUDY) Commercial catch abundance/landings (1 study): One replicated, before-and-after study in the North Sea/North Atlantic Ocean reported that a ban on high grading did not eliminate the discarding of legal-sized but unwanted common megrim Lepidorhombus whiffiagonis that were required to be landed. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3823https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3823Fri, 27 May 2022 08:55:44 +0100
What Works 2021 cover

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.

More about What Works in Conservation

Download free PDF or purchase
The Conservation Evidence Journal

The Conservation Evidence Journal

An online, free to publish in, open-access journal publishing results from research and projects that test the effectiveness of conservation actions.

Read the latest volume: Volume 21

Go to the CE Journal

Discover more on our blog

Our blog contains the latest news and updates from the Conservation Evidence team, the Conservation Evidence Journal, and our global partners in evidence-based conservation.


Who uses Conservation Evidence?

Meet some of the evidence champions

Endangered Landscape ProgrammeRed List Champion - Arc Kent Wildlife Trust The Rufford Foundation Save the Frogs - Ghana Mauritian Wildlife Supporting Conservation Leaders
Sustainability Dashboard National Biodiversity Network Frog Life The international journey of Conservation - Oryx Cool Farm Alliance UNEP AWFA Bat Conservation InternationalPeople trust for endangered species Vincet Wildlife Trust