Collected Evidence: Collected Evidence: Set longlines at night to reduce seabird bycatch Six out of eight studies from fisheries around the world found lower rates of seabird bycatch on longlines set at night, compared with during the day, or with previously collected data. However, effects seemed to depend on the species caught. Two studies found higher rates of bycatch on night-set longlines, due to high numbers of white-chinned petrels Procellaria aequinoctialis or northern fulmars Fulmarus glacialis being caught at night.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F283https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F283Tue, 24 Jul 2012 13:04:04 +0100Collected Evidence: Collected Evidence: Turn deck lights off during night-time setting of longlines to reduce bycatchA single replicated and controlled study in the South Atlantic found significantly lower bycatch rates when deck lights were turned off during line setting at night.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F284https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F284Tue, 24 Jul 2012 14:11:52 +0100Collected Evidence: Collected Evidence: Use streamer lines to reduce seabird bycatch on longlines A total of eight studies and two literature reviews from coastal and pelagic fisheries across the world found strong evidence for reduced seabird bycatch on longlines when streamer lines were used. A replicated, controlled trial from the sub-Antarctic Indian Ocean found no reduction in bycatch rates when using streamer lines, whilst five studies were inconclusive, uncontrolled or had weak evidence for reductions. The effect of streamer lines appears to vary between seabird species: northern fulmars Fulmarus glacialis were consistently caught at lower rates when streamers were used but shearwaters Puffinus spp. and white-chinned petrels Procellaria aequinoctialis were caught at similar rates with and without streamers in one study each. The three studies that investigated the use of multiple streamer lines all found that fewer birds were caught when two streamer lines were used, compared to one, with even fewer caught when three were used.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F285https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F285Tue, 24 Jul 2012 14:37:19 +0100Collected Evidence: Collected Evidence: Use larger hooks to reduce seabird bycatch We captured no intervention-based evidence on the impact of large hooks on seabird bycatch. 'No evidence' for an action means we have not yet found any studies that directly and quantitatively tested this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action    Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F286https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F286Tue, 24 Jul 2012 16:26:21 +0100Collected Evidence: Collected Evidence: Use a water cannon when setting longlines to reduce seabird bycatch We found no evidence for the effects on seabird bycatch rates of using water cannon when setting longlines. 'No evidence' for an action means we have not yet found any studies that directly and quantitatively tested this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this actionCollected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F287https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F287Tue, 24 Jul 2012 16:27:42 +0100Collected Evidence: Collected Evidence: Set lines underwater to reduce seabird bycatch Four replicated and controlled studies and a literature review in Norway, South Africa and the North Pacific found reductions in northern fulmar Fulmarus glacialis, albatross and petrel bycatch rates when using an underwater setting funnel. Although one found a disproportionate number of albatross were caught during day line setting. A replicated and controlled study found that underwater setting increased attack rates of shearwaters Puffinus spp. on longlines and did not reduce bycatch.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F288https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F288Tue, 24 Jul 2012 16:38:44 +0100Collected Evidence: Collected Evidence: Set longlines at the side of the boat to reduce seabird bycatch We found no evidence for the effects on seabird bycatch rates of setting longlines from the side of the boat. 'No evidence' for an action means we have not yet found any studies that directly and quantitatively tested this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F289https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F289Tue, 24 Jul 2012 16:44:03 +0100Collected Evidence: Collected Evidence: Use a line shooter to reduce seabird bycatch A randomised, replicated and controlled trial from a pelagic fishery in the North Pacific found significantly higher seabird bycatch when a line shooter was used to set longlines. A second randomised, replicated and controlled trial (from Norway), found no effect of a line shooter on bycatch rates.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F290https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F290Tue, 24 Jul 2012 16:47:45 +0100Collected Evidence: Collected Evidence: Tow buoys behind longlining boats to reduce seabird bycatch We found no evidence for the effects on seabird bycatch rates of towing buoys behind longlining boats. 'No evidence' for an action means we have not yet found any studies that directly and quantitatively tested this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F292https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F292Tue, 24 Jul 2012 16:54:34 +0100Collected Evidence: Collected Evidence: Use high-visibility longlines to reduce seabird bycatch We captured no intervention-based evidence on the impact on seabird bycatch of high-visibility longlines. 'No evidence' for an action means we have not yet found any studies that directly and quantitatively tested this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.    Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F294https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F294Tue, 24 Jul 2012 16:58:27 +0100Collected Evidence: Collected Evidence: Thaw bait before setting lines to reduce seabird bycatchA single study from Australia found that lines set using thawed baits caught significantly fewer seabirds than controls.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F298https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F298Tue, 24 Jul 2012 17:24:13 +0100Collected Evidence: Collected Evidence: Reduce seabird bycatch by releasing offal overboard when setting longlinesTwo replicated and controlled studies in the South Atlantic and sub-Antarctic Indian Ocean found significant reductions in the number of albatross and petrels attacking baits and being caught when offal was released overboard during line setting.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F299https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F299Tue, 24 Jul 2012 17:39:55 +0100Collected Evidence: Collected Evidence: Use high-visibility mesh on gillnets to reduce seabird bycatch A repeated, randomised and controlled trial in the USA found that having gillnets made partially from high-visibility mesh was effective in reducing seabird bycatch. Having a greater percentage (25% vs. 10%) of the net made from high-visibility mesh was more effective, but also reduced catch of the target species.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F303https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F303Tue, 24 Jul 2012 18:10:09 +0100Collected Evidence: Collected Evidence: Reduce gillnet deployment time to reduce seabird bycatch We found no evidence for the effects on seabird bycatch rates of reducing gill net deployment time. 'No evidence' for an action means we have not yet found any studies that directly and quantitatively tested this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.    Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F304https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F304Tue, 24 Jul 2012 18:11:14 +0100Collected Evidence: Collected Evidence: Reduce bycatch by employing seasonal or area closures We found no evidence for the effects on seabird populations or bycatch rates of seasonal or area closures. 'No evidence' for an action means we have not yet found any studies that directly and quantitatively tested this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.    Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F307https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F307Tue, 24 Jul 2012 18:19:08 +0100Collected Evidence: Collected Evidence: Install exclusion devices on fishing gear: Sea turtles Three studies evaluated the effects of installing exclusion devices on fishing gear on sea turtle populations. One study was in the Gulf of Mexico (USA), one was in the Mid-Atlantic (USA) and one was off the coast of Western Australia. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Survival (1 study): One replicated, before-and-after study in the Gulf of Mexico found that when exclusion grids with escape holes were used in a shrimp trawl fishery there were fewer lethal strandings of loggerhead turtles compared to when grids were not used. BEHAVIOUR (1 STUDY) Use (1 study): One controlled study in the Mid-Atlantic found that when exclusion devices were used on scallop dredges there were fewer interactions with sea turtles than when no devices were used. OTHER (1 STUDY) Unwanted catch (1 study): One replicated study off the coast of Western Australia found that exclusion grids with escape hatches prevented sea turtles entering trawl nets. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3584https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3584Wed, 08 Dec 2021 15:30:20 +0000Collected Evidence: Collected Evidence: Install exclusion devices on fishing gear: Tortoises, terrapins, side-necked & softshell turtles Thirteen studies evaluated the effects of installing exclusion devices on fishing gear on tortoise, terrapin, side-necked & softshell turtle populations. Ten studies were in the USA, two were in Canada and one was in Australia. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Survival (1 study): One replicated, randomized, paired, controlled study in the USA found that fewer turtles died in hoop nets with an exclusion device than in unmodified traps. BEHAVIOUR (1 STUDY) Use (1 study): One randomized, controlled trial in the USA found mixed effects of crab pot exclusion devices on use of pots by diamondback terrapins depending on the device design. OTHER (13 STUDIES) Unwanted catch (13 studies): Eight of 13 controlled studies (including seven replicated, paired studies) in the USA, Australia and Canada found that crab pots, fyke nets, hoop nets and eel traps with exclusion devices caught fewer turtles, diamond back terrapins and short-necked turtles than unmodified gear. Two studies also found that modified gear caught smaller short-necked turtles and diamondback terrapins than unmodified gear. Three studies found mixed effects of exclusion devices on unwanted catch of turtles and diamondback terrapins depending on the device design. The other two studies found that that crab pots with wire exclusion devices or magnetized exclusion devices caught a similar number of diamondback terrapins compared to unmodified pots. One study also found that crab pots with wire exclusion devices caught larger diamondback terrapins than pots with plastic exclusion devices. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3590https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3590Wed, 08 Dec 2021 16:11:04 +0000Collected Evidence: Collected Evidence: Install exclusion devices on fishing gear: Snakes & lizards One study evaluated the effects of installing exclusion devices on fishing gear on snake and lizard populations. This study was in Australia. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (1 STUDY) Unwanted catch (1 study): One replicated study off the coast of Western Australia found that exclusion grids did not prevent sea snakes from entering trawl nets. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3599https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3599Wed, 08 Dec 2021 16:47:50 +0000Collected Evidence: Collected Evidence: Install escape devices on fishing gear: Sea turtles One study evaluated the effects of installing escape devices on fishing gear on sea turtle populations. This study was in the Gulf of Carpentaria (Australia). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (1 STUDY) Unwanted catch (1 Study): One randomized, paired, controlled study in the Gulf of Carpentaria found that trawl nets with escape devices caught a similar number of sea turtles compared to unmodified nets. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3601https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3601Wed, 08 Dec 2021 17:09:33 +0000Collected Evidence: Collected Evidence: Install escape devices on fishing gear: Snakes & lizards Three studies evaluated the effects of installing escape devices on fishing gear on snake and lizard populations. All three studies were in the Gulf of Carpentaria (Australia). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (3 STUDIES) Unwanted catch (3 Studies): One of two paired, controlled studies (including one randomized and one replicated study) in the Gulf of Carpentaria found that trawl nets with escape devices caught a similar number of sea snakes compared to unmodified nets. The other study found that trawl nets with an escape device caught fewer sea snakes compared to unmodified nets. One replicated, paired, controlled study in the Gulf of Carpentaria found that the placement of escape devices trawl nets affected the number of sea snakes caught compared to unmodified nets. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3603https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3603Thu, 09 Dec 2021 10:08:51 +0000Collected Evidence: Collected Evidence: Install exclusion and escape devices on fishing gear Six studies evaluated the effects of installing exclusion and escape devices on fishing gear on reptile populations. Two studies each were off the coast of Australia, in the Gulf of Carpentaria (Australia) and in the Adriatic Sea. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (2 STUDIES) Use (2 studies): Two replicated studies (including one controlled study) in the Adriatic Sea found that one or two loggerhead turtles were able to escape from a trawl net with an exclusion and escape device. OTHER (5 STUDIES) Unwanted catch (5 studies): Four studies (including two replicated, paired, controlled studies) off the coast of Australia and in the Gulf of Carpentaria (Australia) found that that trawl nets with an exclusion and escape device caught fewer loggerhead turtles or sea turtles and sea snakes compared to unmodified nets. One replicated study in the Adriatic Sea found that no loggerhead turtles were caught by a trawl net with an exclusion and escape device. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3605https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3605Thu, 09 Dec 2021 10:22:38 +0000Collected Evidence: Collected Evidence: Use a different bait type: Sea turtles Nine studies evaluated the effects of using a different bait type on sea turtle populations. Three studies were in each of the Atlantic and Pacific, and one was in each of the Atlantic and north Pacific, the Gulf of Garbes (Tunisia) and Italy. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (2 STUDIES) Survival (2 studies): Two studies (including one replicated, controlled study) off the coast of Hawaii and in the Southern Atlantic found that the percentage of loggerhead and leatherback turtles that survived being caught by fish-baited or squid-baited hooks or fish-baited circle hooks and squid-baited J-hooks was similar. Condition (1 study): One before-and-after study off the coast of Hawaii found that fish-baited circle hooks deeply hooked fewer leatherback and hard-shell turtles compared to squid-baited J-hooks. BEHAVIOUR (1 STUDY) Use (1 study): One controlled study in Italy found that loggerhead turtles in a captive setting were less likely to bite at fish bait than squid bait. The study also found that smaller turtles were more likely to bite at mackerel bait and larger turtles at squid bait. OTHER (8 STUDIES) Unwanted catch (8 studies): Four of five studies (including one replicated, paired, controlled study) in the North Pacific, Eastern Pacific, Atlantic and Atlantic and North Pacific found that fish-baited hooks caught fewer sea turtles or were swallowed by fewer olive ridley turtles than squid baited hooks. One study also found that fish bait in combination with larger circle hooks lead to the highest percentage of external hookings. The other study found mixed effects of using fish or squid-baited hooks on the unwanted catch of hard-shell and leatherback turtles. One replicated, controlled study in the north-western Atlantic Ocean found that fish-baited J-hooks caught fewer sea turtles compared to squid-baited hooks. The study also found that unwanted catch was more similar for fish-baited and squid-baited circle hooks. One before-and-after study off the coast of Hawaii found that fish-baited circle hooks caught fewer loggerhead and leatherback turtles compared to compared to squid-baited J-hooks. One replicated study in the Gulf of Garbes found that hooks baited with stingray caught fewer loggerhead turtles compared to fish-baited hooks. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3612https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3612Thu, 09 Dec 2021 12:02:07 +0000Collected Evidence: Collected Evidence: Establish handling and release procedures for accidentally captured or entangled (‘bycatch’) reptiles One study evaluated the effects on reptiles of establishing handling and release procedures for accidentally captured or entangled reptiles. This study was in Canada. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Condition (1 study): One replicated, controlled study in Canada in a captive setting found that recovery of painted turtles after a long period of being held underwater was similar when turtles recovered out of the water or in the water. BEHAVIOUR (0 STUDIES) OTHER (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3621https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3621Thu, 09 Dec 2021 13:31:57 +0000Collected Evidence: Collected Evidence: Release accidentally caught (‘bycatch’) reptiles Three studies evaluated the effects on reptile populations of releasing accidentally caught reptiles. One study was in each of the Caribbean Sea, Costa Rica and the Republic of Korea. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (2 STUDIES) Survival (2 studies): One replicated study in the Caribbean Sea found that from a released group of green turtles that included some accidentally caught and some head-started individuals, some survived for at least several months in the wild. One replicated study in the Republic of Korea found that green turtles caught in pound nets all survived for at least two weeks to a year after release. BEHAVIOUR (1 STUDY) Behaviour change (1 study): One controlled study off the Pacific coast of Costa Rica found that the behaviour of longline-caught sea turtles following release was broadly similar to free-swimming turtles. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3624https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3624Thu, 09 Dec 2021 13:37:44 +0000Collected Evidence: Collected Evidence: Set catch shares by species One study examined the effects of setting catch shares by species on marine fish populations. The study was in the Pacific Ocean (Canada).   COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (1 STUDY) Reduction of unwanted catch (1 study): One before-and-after study in the Pacific Ocean found that after a species-specific catch share was set (Individual Vessel Bycatch Quota) unwanted halibut catch in a multi-species fishery was reduced, whereas it was higher under a previous catch share system (Individual Transferable Quota) based on all species in the catch. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3814https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3814Fri, 27 May 2022 08:31:55 +0100
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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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