Conservation Evidence: Evidence Data

Collected Evidence: Collected Evidence: Use alerts to reduce grey partridge by-catch during shoots We have captured no evidence for the effects of using alerts to reduce grey partridge by-catch during shoots on farmland wildlife. '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%2F102https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F102Mon, 24 Oct 2011 21:57:01 +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: Use a sonic scarer when setting longlines to reduce seabird bycatchA single study from the South Atlantic found that seabird bycatch rates did not appear to be lower on longlines set with a sonic scarer, and that changes in seabird behaviour due to the scarer were only temporary. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F295https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F295Tue, 24 Jul 2012 16:59:51 +0100Collected Evidence: Collected Evidence: Use acoustic alerts on gillnets to reduce seabird bycatchA repeated, randomised and controlled trial in the USA found that sonic alerts reduced the number of common guillemots Uria aalge but not rhinoceros auklets Cerorhinca monocerata caught in gillnets. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F301https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F301Tue, 24 Jul 2012 18:02:45 +0100Collected Evidence: Collected Evidence: Use alley croppingParasitism, infection and predation: Two of four studies from Kenya and the USA (including three randomised, replicated, controlled trials) found that effects of alley cropping on parasitism varied between study sites, sampling dates, pest life stages or the width of crop alleys. Two studies found no effect on parasitism. One study found mixed effects on fungal infections in pests and one study found lower egg predation. Natural enemies: One randomised, replicated, controlled study from Kenya found more wasps and spiders but fewer ladybirds. Some natural enemy groups were affected by the types of trees used in hedges. Pests and crop damage: Two of four replicated, controlled studies (two also randomised) from Kenya, the Philippines and the UK found more pests in alley cropped plots. One study found fewer pests and one study found effects varied with pest group and between years. One study found more pest damage to crops but another study found no effect. Weeds: One randomised, replicated, controlled study from the Philippines found mixed effects on weeds, with more grasses in alley cropped than conventional fields under some soil conditions. Yield: One controlled study from the USA found lower yield and one study from the Philippines reported similar or lower yields. Costs and profit: One study from the USA found lower costs but also lower profit in alley cropped plots. Crops studied were alfalfa, barley, cowpea, maize, pea, rice and wheat.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F718https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F718Thu, 30 May 2013 10:53:35 +0100Collected Evidence: Collected Evidence: Use alley croppingA controlled, randomized, replicated study from Canada found that intercropping with trees resulted in a higher diversity of arbuscular mycorrhizal fungi. SOIL TYPES COVERED: sandy-loam. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F903https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F903Wed, 02 Oct 2013 08:57:33 +0100Collected Evidence: Collected Evidence: Use alternative means of getting mussel seeds rather than dredging from natural mussel beds We found no studies that evaluated the effects of using alternative means of getting mussel seeds rather than dredging from natural mussel beds on subtidal benthic invertebrate 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%2F2122https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2122Tue, 22 Oct 2019 10:14:55 +0100Collected Evidence: Collected Evidence: Use a smaller beam trawl One study examined the effects of using a smaller beam trawl on subtidal benthic invertebrates. The study was in the North Sea (Germany and Netherlands). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Overall abundance (1 study): One replicated, paired, controlled study in the North Sea found that a smaller beam trawl caused similar mortality of invertebrates in the trawl tracks compared to a larger beam trawl. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2127https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2127Tue, 22 Oct 2019 10:23:07 +0100Collected Evidence: Collected Evidence: Use a square mesh instead of a diamond mesh codend on trawl nets One study examined the effects of using a square mesh instead of a diamond mesh codend on trawl nets on unwanted catch of subtidal benthic invertebrate populations. The study was in the English Channel (UK). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Unwanted catch abundance (1 study): One replicated, paired, controlled study in the English Channel found that a trawl net with a square mesh codend caught less non-commercial unwanted invertebrates in one of two areas, and similar amounts in the other area, compared to a standard diamond mesh codend. OTHER (1 STUDY) Commercial catch abundance (1 study): One replicated, paired, controlled study in the English Channel found that a trawl net with a square mesh codend caught similar amounts of commercially targeted fish species in two areas, and that in one of two areas it caught more commercially important shellfish, compared to a standard diamond mesh codend. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2136https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2136Tue, 22 Oct 2019 10:56:11 +0100Collected Evidence: Collected Evidence: Use alternative de-icers on roads We found no studies that evaluated the effects on mammals of using alternative de-icers on roads. ‘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%2F2616https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2616Fri, 12 Jun 2020 09:06:31 +0100Collected Evidence: Collected Evidence: Use a separator trawl Two studies examined the effect of using a separator trawl on marine fish populations. One study was in the North Sea (UK) and the other in the Atlantic Ocean (Portugal). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (2 STUDIES) Reduction of unwanted catch (2 studies): One replicated, randomized study in the North Sea found that a separator trawl separated unwanted cod from target fish species into the lower codend, where a larger mesh size allowed more unwanted smaller cod to escape capture. One replicated study in the Atlantic Ocean found that a separator trawl fitted with a square-mesh escape panel caught less of one of two unwanted fish species in a crustacean fishery. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2711https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2711Tue, 29 Dec 2020 16:27:31 +0000Collected Evidence: Collected Evidence: Use 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%2Fwww.conservationevidence.com%2Factions%2F2712https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2712Tue, 29 Dec 2020 16:31:56 +0000Collected Evidence: Collected Evidence: Use a square mesh instead of a diamond mesh codend in a trawl net Twenty-six studies examined the effects of using a square mesh instead of a diamond mesh codend in a trawl net on marine fish populations. Five studies were in the North Atlantic Ocean (Canada, Portugal, USA), four were in the Aegean Sea (Greece, Turkey), three were in the Mediterranean Sea (Spain) and the Tasman Sea (Australia), two studies were in each of the English Channel (UK), the Adriatic Sea (Italy) and the South Pacific Ocean (Australia, Chile), and one study was in each of the Greenland Sea (Iceland), the North Pacific Ocean (USA), the Bristol Channel (UK), the Kattegat and the Skagerrak (Denmark) and the Coral Sea (Australia). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (2 STUDIES) Survival (2 studies): One of two replicated, paired, controlled studies in the Aegean Sea and Bristol Channel found that the short-term survival of two of six fish species was higher after escaping through a square mesh compared to a diamond mesh codend. The other study reported that skate caught in a square mesh codend had a higher overall survival likelihood than those caught in a diamond mesh codend. BEHAVIOUR (0 STUDIES) OTHER (25 STUDIES) Reduction of unwanted catch (16 studies): Ten of 16 replicated, controlled studies (including five paired, three randomized and three randomized and paired) in the Greenland Sea, Aegean Sea, Atlantic Ocean, Tasman Sea, Pacific Ocean, Mediterranean Sea, English Channel, Bristol Channel and Coral Sea, found that square mesh codends reduced the unwanted (non-target or non-marketable/discarded) catches of all fish species monitored, young individuals of half or most commercially targeted fish, total unwanted catch (fish and invertebrates), and discarded fish in deeper but not shallower fishing areas, compared to diamond mesh codends; and two of those studies also found that there was a variable effect on unwanted catch between individual fish species/groups. Four studies found no reduction in catches of unwanted small rockfish and flatfish, three of four commercially important bottom fish species, total unwanted catch (fish and invertebrates), or the total number of unwanted species (fish and invertebrates), compared to diamond mesh codends. One study found that square mesh codends retained more fish overall than diamond mesh but varied for individual species by fish shape and size. One study found that unwanted fish catch depended on codend mesh size as well as configuration (square or diamond). Two of the studies, where square mesh codends had no or a varied effect, also found that size selectivity increased with increases in mesh size for both square and diamond mesh codends. Improved size-selectivity of fishing gear (14 studies): Six of 14 replicated, controlled studies (including three paired, one randomized and one randomized and paired) in the Atlantic Ocean, Mediterranean Sea, Adriatic Sea, Aegean Sea, English Channel, Pacific Ocean, Tasman Sea and the Kattegat and Skagerrak, found that using a square mesh codend in a trawl net (bottom and pelagic) improved size selectivity for silver hake, horse mackerel, European hake, axillary seabream, poor cod, greater forkbeard, blue whiting, discarded fish and three of four commercially targeted fish, compared to diamond mesh codends. Five studies found no difference in size selectivity between square and diamond mesh codends for Atlantic mackerel, long rough dab, yellowtail scad and striped seapike, rockfish and flatfish, and three of four commercially important bottom fish species. The other three studies found that the effect of square mesh instead of diamond mesh codends varied with fish body shape (round or flat), and for three of three and five of five roundfish species size selectivity was improved, but not for one flatfish. Two of the studies, where square mesh codends had either no or a varied effect, also found that size selectivity increased with increases in mesh size for both square and diamond mesh codends. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2714https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2714Fri, 01 Jan 2021 14:39:22 +0000Collected Evidence: Collected Evidence: Use acoustic devices at renewable energy sites We found no studies that evaluated the effects of using acoustic devices at renewable energy sites on marine and freshwater mammal populations. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated 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%2F2748https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2748Tue, 02 Feb 2021 16:48:11 +0000Collected Evidence: Collected Evidence: Use acoustic devices at cooling water intake structures We found no studies that evaluated the effects of using acoustic devices at cooling water intake structures on marine and freshwater mammal populations. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated 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%2F2751https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2751Tue, 02 Feb 2021 16:53:08 +0000Collected Evidence: Collected Evidence: Use acoustic devices on moving vessels We found no studies that evaluated the effects of using acoustic devices on moving vessels on marine and freshwater mammal populations. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated 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%2F2761https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2761Tue, 02 Feb 2021 17:05:37 +0000Collected Evidence: Collected Evidence: Use acoustic devices at aquaculture systems Six studies evaluated the effects on marine and freshwater mammals of using acoustic devices at aquaculture systems. Four studies were in the North Atlantic Ocean (USA, UK), one was in the Reloncaví fjord (Chile) and one in the Mediterranean Sea (Italy). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (6 STUDIES) Human-wildlife conflict (6 studies): Four of six studies (including five before-and-after and/or site comparison studies and one controlled study) in the North Atlantic Ocean, the Reloncaví fjord and the Mediterranean Sea found that using acoustic devices at salmon farms reduced predation on caged salmon by grey seals, harbour seals and South American sea lions, or reduced the number of harbour seals approaching a fish cage. The two other studies found that using acoustic devices did not reduce harbour seal predation at salmon farms, or reduce the presence, approach distances, groups sizes or time spent around fin-fish farms by common bottlenose dolphins. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2775https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2775Thu, 04 Feb 2021 15:29:04 +0000Collected Evidence: Collected Evidence: Use a smaller mesh size for fishing nets We found no studies that evaluated the effects of using a smaller mesh size for fishing nets on marine and freshwater mammal populations. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated 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%2F2802https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2802Thu, 04 Feb 2021 17:11:57 +0000Collected Evidence: Collected Evidence: Use acoustically reflective fishing gear materials Five studies evaluated the effects on marine mammals of using acoustically reflective fishing gear materials. Two studies were in the Bay of Fundy (Canada) and one study was in each of the Fortune Channel (Canada), the North Sea (Denmark) and the South Atlantic Ocean (Argentina). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (2 STUDIES) Behaviour change (2 studies): One controlled study in the Fortune Channel found that harbour porpoises approached nets made from acoustically reflective material (barium sulfate) and conventional nets to similar distances and for similar durations, but porpoises used fewer echolocation clicks at barium sulfate nets. One controlled study in the Bay of Fundy found that harbour porpoise echolocation activity was similar at barium sulfate and conventional nets. OTHER (3 STUDIES) Reduction in entanglements/unwanted catch (3 studies): Two of three controlled studies (including two replicated studies) in the North Sea, the Bay of Fundy and the South Atlantic Ocean found that fishing nets made from acoustically reflective materials (iron-oxide or barium sulfate) had fewer entanglements of harbour porpoises than conventional fishing nets. The other study found that nets made from barium sulfate did not reduce the number of dolphin entanglements. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2807https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2807Thu, 04 Feb 2021 17:31:28 +0000Collected Evidence: Collected Evidence: Use acoustic devices on fishing gear Thirty-three studies evaluated the effects on marine mammals of using acoustic devices on fishing gear. Eight studies were in the North Atlantic Ocean (Canada, USA, UK), four studies were in each of the North Pacific Ocean (USA) and the North Sea (Germany, Denmark, UK), three studies were in the Mediterranean Sea (Spain, Italy), two studies were in each of the Fortune Channel (Canada), the South Atlantic Ocean (Argentina, Brazil) and the Baltic Sea (Denmark, Germany, Sweden), and one study was in each of Moreton Bay (Australia), the Black Sea (Turkey), the Celtic Sea (UK), the South Pacific Ocean (Peru), the Rainbow Channel (Australia), the UK (water body not stated), the Great Belt (Denmark), Omura Bay (Japan), and the Indian Ocean (Australia). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (16 STUDIES) Behaviour change (16 studies): Twelve of 16 controlled studies (including three replicated studies) in the North Atlantic Ocean, the Fortune Channel, the South Atlantic Ocean, Moreton Bay, the Mediterranean Sea, the Celtic Sea, the Rainbow Channel, a coastal site in the UK, the Great Belt, the North Sea, Omura Bay and the Indian Ocean found that using acoustic devices on fishing nets, float lines or simulated fishing nets resulted in harbour porpoises, common bottlenose dolphins, tuxuci dolphins, finless porpoises and seals approaching nets or lines less closely, having fewer encounters or interactions with nets, or activity and sightings were reduced in the surrounding area. The other four studies found that using acoustic devices on trawl nets, float lines or simulated fishing nets did not have a significant effect on the behaviour of common bottlenose dolphins, harbour porpoises, Indo-Pacific humpback dolphins or dugongs. OTHER (19 STUDIES) Reduction in entanglements/unwanted catch (14 studies): Nine studies (including seven controlled studies and two before-and after studies) in the North Atlantic Ocean, the North Sea, the South Atlantic Ocean, the North Pacific Ocean, the Black Sea, and the South Pacific Ocean found that using acoustic devices on cod traps or fishing nets resulted in fewer collisions of humpback whales or entanglements of harbour porpoises, Franciscana dolphins, beaked whales and small cetaceans. Three studies (including two controlled studies and one before-and-after study) in the North Pacific Ocean found that using acoustic devices on fishing nets resulted in fewer entanglements of some species but not others. One controlled study in the North Atlantic Ocean found that fishing nets with a ‘complete’ set of acoustic devices had fewer entanglements of harbour porpoises, but those with an ‘incomplete’ set did not. One replicated, controlled study in the North Sea and Baltic Sea found that using acoustic devices on fishing nets reduced harbour porpoise entanglements in one fishing area but not the other. Human-wildlife conflict (6 studies): Five of six studies (including six controlled studies, one of which was replicated) in the Baltic Sea, the Mediterranean Sea, the North Pacific Ocean, a coastal site in the UK and the North Sea found that using acoustic devices reduced damage to fish catches and/or fishing nets caused by common bottlenose dolphins and seals. The other study found that acoustic devices did not reduce damage to swordfish catches by California sea lions. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2808https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2808Thu, 04 Feb 2021 17:56:14 +0000Collected Evidence: Collected Evidence: Use acoustic devices on fishing vessels Five studies evaluated the effects on marine mammals of using acoustic devices on vessels. One study was in each of the Shannon Estuary (Ireland), the Rainbow Channel (Australia), Keppel Bay (Australia), the North Atlantic Ocean (Azores) and the Indian Ocean (Crozet Islands). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (4 STUDIES) Behaviour change (4 studies): One controlled study in the Shannon Estuary found that common bottlenose dolphins avoided a boat more frequently when acoustic devices of two types were deployed alongside it. One controlled study in the Indian Ocean found that killer whales were recorded further from a fishing vessel when an acoustic device was used during hauls, but distances decreased after the first exposure to the device. Two before-and-after studies in the Rainbow Channel and Keppel Bay found that an acoustic device deployed alongside a vessel reduced surfacing and echolocation rates and time spent foraging or socializing of Indo-Pacific humpback dolphins and Australian snubfin dolphins but there was no effect on 8–10 other types of behaviour (e.g. vocalizing, diving, travelling etc.). OTHER (1 STUDY) Human-wildlife conflict (1 study): One randomized, controlled study in the North Atlantic Ocean found that using acoustic devices of two types did not reduce predation of squid catches by Risso’s dolphins. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2815https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2815Fri, 05 Feb 2021 14:45:12 +0000Collected Evidence: Collected Evidence: Use acoustic devices on moorings Eight studies evaluated the effects on marine and freshwater mammals of using acoustic devices on moorings. Two studies were in the South Pacific Ocean and one study was in each of the Puntledge River (Canada), the Bay of Fundy (Canada), the Shannon Estuary (Ireland), the Rivers Conon and Esk (UK), the Kyle of Sutherland estuary (UK) and the North Atlantic Ocean (UK). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (7 STUDIES) Behaviour change (7 studies): Two of four controlled studies in the South Pacific Ocean, the Kyle of Sutherland estuary and the North Atlantic Ocean found that deploying acoustic devices on moorings reduced numbers of grey and harbour seals, and the activity of harbour porpoises, short-beaked common dolphins and common bottlenose dolphins. The two other studies found that using an acoustic device on a mooring did not have a significant effect on the number, direction of movement, speed, or dive durations of migrating humpback whales. One controlled study in the Bay of Fundy found that using an acoustic device on a mooring reduced harbour porpoise echolocation activity, but the probability of porpoises approaching within 125 m of the device increased over 10–11 days. One controlled study in the Shannon Estuary found that one of two types of acoustic device reduced the activity of common bottlenose dolphins. One replicated, controlled study in the Rivers Conon and Esk found that using acoustic devices reduced the number of grey and harbour seals upstream of the device but did not reduce seal numbers overall. OTHER (1 STUDY) Human-wildlife conflict (1 study): One randomized controlled study in the Puntledge River found that deploying an acoustic device on a mooring reduced the number of harbour seals feeding on migrating juvenile salmon. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2816https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2816Fri, 05 Feb 2021 15:00:49 +0000Collected Evidence: Collected Evidence: Use acoustic decoys to divert mammals away from fishing gear One study evaluated the effects on marine mammals of using acoustic decoys to divert mammals away from fishing gear. The study was in the Gulf of Alaska (USA). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (1 STUDY) Behaviour change (1 study): One study in the Gulf of Alaska found that increasing the distance between an acoustic decoy device and fishing lines resulted in fewer sperm whales at the lines, but sperm whale presence and time of arrival did not differ. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2820https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2820Fri, 05 Feb 2021 15:15:05 +0000Collected Evidence: Collected Evidence: Use acoustic devices to deter marine and freshwater mammals from an area to reduce noise exposure Four studies evaluated the effects of using acoustic devices to deter marine and freshwater mammals from an area to reduce noise exposure. Two studies were in the North Sea (Germany), one study was in the Great Belt (Denmark) and one was in Faxaflói Bay (Iceland). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (4 STUDIES) Behaviour change (4 studies): Three studies (including two controlled and one before-and-after study) in the North Sea and the Great Belt found that using acoustic devices to deter mammals from an area at a wind farm construction site or pelagic sites reduced the activity and sightings of harbour porpoises at distances of 1–18 km from the devices. One before-and-after study in Faxaflói Bay found that when an acoustic device was deployed from a boat, minke whales swam away from the device, increased their swimming speed, and swam more directly. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2896https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2896Mon, 08 Feb 2021 12:04:42 +0000Collected Evidence: Collected Evidence: Use alternative methods instead of airguns for seismic surveys We found no studies that evaluated the effects of using alternative methods instead of airguns for seismic surveys on marine and freshwater mammal populations. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated 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%2F2899https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2899Mon, 08 Feb 2021 16:10:05 +0000