Collected Evidence: Collected Evidence: Scare birds from fish farms One before-and-after study from Israel found that the population of pygmy cormorants in the area increased after birds were scared away from fish farms, possibly due to lower persecution. One of two studies that examined fish stocks found that fewer fish were taken from a farm when heron distress calls were played. The other study, a literature review, found no evidence for the effects of scaring birds on fish stocks. Two replicated studies from Belgium and Australia found that using foot patrols to disturb birds from fish farms did not reduce the number of birds present or fish consumption. Ten of eleven studies from across the world, three controlled, found evidence that playing distress calls or using other acoustic deterrents (some with flashes of light) reduced the number of birds at fish farms, or changed bird behaviours. One of these involved underwater broadcasting. One study found effects were only temporary and five found that birds became habituated to noises. Four studies, one replicated and controlled, two before-and-after, found that acoustic deterrents were not effective in scaring birds. Five of seven studies, one controlled, found evidence that visual deterrents (including inflatable ‘Scarey Man’ scarecrows) reduced the number of birds at fish farms. Three found evidence for habituation to deterrents and three studies found no evidence that visual deterrents were effective. Two studies examined other deterrents, finding that trained raptors were effective but that the effects of helicopters and ultra-light aircraft were either inconclusive or very temporary.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F244https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F244Wed, 18 Jul 2012 11:00:04 +0100Collected 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: 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: 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: Set or improve minimum sewage treatment standards One study examined the effects of improving minimum sewage treatment standards on subtidal benthic invertebrates. The study was in the Bay of Biscay (Spain).   COMMUNITY RESPONSE (1 STUDY) Overall community composition (1 study): One before-and-after, site comparison study in the Bay of Biscay found that after introducing a secondary treatment of sewage wastewaters, invertebrate community composition at an impacted site did not significantly change compared to unimpacted sites. Overall richness/diversity (1 study): One before-and-after, site comparison study in the Bay of Biscay found that after introducing a secondary treatment of sewage wastewaters, invertebrate richness and diversity at an impacted site did not significantly change compared to unimpacted sites. POPULATION RESPONSE (1 STUDY) Overall abundance (1 study): One before-and-after, site comparison study in the Bay of Biscay found that after introducing a secondary treatment of sewage wastewaters, total cover of invertebrates significantly increased at an impacted site at 8 m but not 3 m depth, compared to unimpacted sites. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2180https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2180Tue, 22 Oct 2019 12:36:42 +0100Collected Evidence: Collected Evidence: Restrict the use of tributyltin or other toxic antifouling coatings Four studies examined the effects of restricting the use of tributyltin as an antifouling coating on subtidal benthic invertebrate populations. One study was located in the English Channel (UK), two in the River Crouch estuary (UK), and one in Otsuchi Bay (Japan).   COMMUNITY RESPONSE (2 STUDIES) Overall community composition (1 study): One replicated, before-and-after study in the River Crouch estuary found that after restricting the use of tributyltin, invertebrate community composition changed, but that changes varied with locations. Overall richness/diversity (1 study): One replicated, before-and-after study in the River Crouch estuary found that after restricting the use of tributyltin, overall invertebrate species richness and diversity increased. POPULATION RESPONSE (2 STUDIES) Molluscs condition (1 study): One replicated, before-and-after study in the English Channel found that after restricting the use of tributyltin, there was a decrease in its concentration in dogwhelks and the penis length of female dogwhelks. Crustacean condition (1 study): One study in Otsuchi Bay found that after restricting the use of tributyltin its concentration decreased in skeleton shrimps. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2214https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2214Tue, 22 Oct 2019 13:30:42 +0100Collected Evidence: Collected Evidence: Translocate habitat-forming (biogenic) species - Translocate reef- or bed-forming molluscs Two studies examined the effects of translocating habitat-forming molluscs on associated subtidal benthic invertebrate populations. Both were in Strangford Lough (UK).   COMMUNITY RESPONSE (2 STUDIES) Overall community composition (2 studies): One replicated, site comparison study in Strangford Lough found that plots with translocated mussels had different associated invertebrate communities to plots without mussels, but also to natural mussel beds. One replicated, controlled study in Strangford Lough found that translocating mussels onto scallop shells or directly onto the seabed led to similar associated invertebrate communities. Overall richness/diversity (2 studies): One replicated, site comparison study in Strangford Lough found that plots with translocated mussels had higher richness and diversity of associated invertebrates to plots without mussels, and similar to natural mussel beds. One replicated, controlled study in Strangford Lough found that translocating mussels onto scallop shells or directly onto the seabed led to similar richness and diversity of associated invertebrates. POPULATION RESPONSE (2 STUDIES) Overall abundance (2 studies): One replicated, site comparison study in Strangford Lough presented unclear abundance results. One replicated, controlled study in Strangford Lough found that translocating mussels onto scallop shells or directly onto the seabed led to higher abundance of associated invertebrates in one of two comparisons. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2245https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2245Wed, 23 Oct 2019 08:48:18 +0100Collected Evidence: Collected Evidence: Translocate habitat-forming (biogenic) species - Translocate reef-forming corals Two studies examined the effects of translocating habitat-forming corals on associated subtidal benthic invertebrate populations. One was in Tayabas Bay (Philippines) and one in the South China Sea (Philippines).   COMMUNITY RESPONSE (2 STUDIES) Overall community composition (1 study): One replicated, controlled, before-and-after study in the South China Sea found that following coral translocation associated invertebrate communities did not change and remained similar to plots without translocated corals. Overall richness/diversity (2 studies): One replicated, controlled, before-and-after study in the South China Sea found that following coral translocation richness of associated invertebrates increased but also increased in plots without corals, likely due to spill-over. One replicated, controlled study in Tayabas Bay found that richness of associated invertebrates was higher in plots with translocated corals than in plots without. POPULATION RESPONSE (1 STUDY) Overall abundance (1 study): One replicated, controlled, before-and-after study in the South China Sea found that following coral translocation abundance of associated invertebrates increased and became higher than in plots without translocated corals. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2246https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2246Wed, 23 Oct 2019 08:52:10 +0100Collected Evidence: Collected Evidence: Restore biogenic habitats (other methods) - Restore mussel beds Two studies examined the effects of restoring mussel beds (not by transplanting or translocating mussels) on mussels and mussel bed-associated subtidal benthic invertebrates. Both were in Strangford Lough (UK).   COMMUNITY RESPONSE (2 STUDIES) Overall community composition (2 studies): One replicated, controlled study in Strangford Lough found that after restoring beds of horse mussels by adding scallop shells to the seabed, overall invertebrate community composition in restored plots was different to that of unrestored plots. One replicated, controlled study in the same area found that after restoring beds of horse mussels by adding scallop shells to the seabed and translocating horse mussels, overall invertebrate community composition in plots restored with shells and mussels was different to plots restored without mussels (shells only), and both were different to unrestored plots and to nearby natural horse mussel beds. Overall species richness/diversity (2 studies): One replicated, controlled study in Strangford Lough found that after restoring beds of horse mussels by adding scallop shells to the seabed, overall invertebrate species diversity was lower in restored plots compared to unrestored plots, but species richness was similar. One replicated, controlled study in the same area found that after restoring beds of horse mussels by adding scallop shells to the seabed and translocating horse mussels, species richness and diversity were higher in restored plots with mussels and shells compared to plots with shells only, and similar to nearby natural horse mussel beds. POPULATION RESPONSE (1 STUDY) Overall abundance (1 study): One replicated, controlled study in Strangford Lough found that after restoring beds of horse mussels by adding scallop shells to the seabed, overall invertebrate abundance was higher in restored plots compared to unrestored plots. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2247https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2247Wed, 23 Oct 2019 09:33:18 +0100Collected Evidence: Collected Evidence: Restore biogenic habitats (other methods) - Restore oyster reefs Eight studies examined the effects of restoring oyster reefs (not by transplanting or translocating oysters) on oysters and oyster reef-associated subtidal benthic invertebrates. Two were in the Gulf of Mexico (USA), one was a global review, four were in the North Pacific Ocean (USA), and one was in the Mission-Aransas estuary (USA).   COMMUNITY RESPONSE (3 STUDIES) Overall community composition (2 studies): One of two replicated, controlled studies in the Gulf of Mexico and the Mission-Aransas estuary found that after restoring eastern oyster reefs, the community composition of combined mobile decapod invertebrates and fish was similar on all types of restoration material used, but the other found that composition varied with the material used. Overall species richness/diversity (3 studies): One replicated, site comparison study in the Gulf of Mexico found that diversity of reef-associated invertebrates was similar in reefs restored by laying rocks regardless of age, in young reefs restored by laying oyster shells, and in natural reefs, but lower in old shell-restored reefs. One replicated, controlled study in the Gulf of Mexico found that diversity of reef-associated invertebrates was higher in all restored reefs than on unrestored sediment, but that diversity varied between the restoration materials used. One replicated, controlled study in the Mission-Aransas estuary found that diversity of fish, crabs and shrimps varied with the restoration material used. POPULATION RESPONSE (7 STUDIES) Overall abundance (2 studies): One replicated, site comparison study in the Gulf of Mexico found that the effect of restoring eastern oyster reefs on the abundance of reef-associated invertebrates depended on the material used for restoration and the age of the reef. One replicated, controlled study in the Gulf of Mexico found that abundance of combined reef-associated mobile decapod invertebrate and fish was similar on all restored reefs regardless of the restoration material used, and higher than on unrestored sediment. Crustacean abundance (1 study): One replicated, controlled study in the Mission-Aransas estuary found that after restoring eastern oyster reefs, crab abundance, but not biomass, and shrimp biomass, but not abundance, varied with the restoration material used. Oyster abundance (6 studies): One replicated, site comparison study in the Gulf of Mexico found that oyster reefs restored by laying rocks had similar oyster abundance to natural reefs, and higher than reefs restored by laying oyster shells. One replicated, controlled study in the Mission-Aransas estuary found that oyster cover and abundance varied with the restoration material used. One replicated, controlled study in the Gulf of Mexico found that oyster spat abundance was similar on all types of restoration material used, and higher than on unrestored sediment. Three replicated, controlled studies in the North Pacific Ocean found that restoring oyster reefs by placing lines of clam shells below Mean Lower Low Water (MLLW) led to higher cover of clam shells by oysters than when placing the lines above MLLW, that for those placed below MLLW, keeping them there led to similar cover compared to moving them above MLLW halfway through the study, and that placing the lines on cobbly seabed led to similar cover compared to placing them on muddy seabed. Oyster reproductive success (3 studies): Three replicated, controlled studies in the North Pacific Ocean found that restoring oyster reefs by placing lines of clam shells below Mean Lower Low Water (MLLW) led to higher recruitment of oyster spat on clam shells than by lacing lines above MLLW, that recruitment was higher on lines placed on cobbly seabed than on muddy seabed, and that recruitment was similar on lines placed near or far from the nearest adult oyster populations. Oyster survival (5 studies): One global systematic review found that two of nine restoration techniques (restoring oyster reef by transplanting juveniles, and by creating no-harvest sanctuaries) assessed resulted in over 85% survival of restored oysters. Four replicated, controlled studies in the North Pacific Ocean found that restoring oyster reefs by placing lines of clam shells below Mean Lower Low Water (MLLW) led to similar survival of oysters than when placing the lines above MLLW, but that for those placed below MLLW, moving them above MLLW halfway through the study led to higher survival than keeping then below, that survival was similar on lines placed on cobbly seabed or muddy seabed, and that survival was similar on lines placed near or far from the nearest adult oyster populations. Oyster condition (5 studies): One replicated, controlled study in the Gulf of Mexico found that the effect of restoring eastern oyster reefs on average spat size varied with the restoration material used. One replicated, controlled study in the North Pacific Ocean found that restoring oyster reefs by placing lines of clam shells below Mean Lower Low Water (MLLW) led to similar growth of oysters on the shells than placing lines above MLLW. Four replicated, controlled studies in the North Pacific Ocean found that restoring oyster reefs by placing lines of clam shells below Mean Lower Low Water (MLLW) led to higher cover of clam shells by non-native species than placing lines above MLLW, but that for those placed below MLLW, moving them above MLLW halfway through the study led to lower cover than keeping then below, that cover was similar on lines placed on cobbly seabed or muddy seabed, and that cover of clam shells by non-native species was higher on lines placed near compared to far from the nearest adult oyster populations. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2248https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2248Wed, 23 Oct 2019 09:37:47 +0100Collected Evidence: Collected Evidence: Restore biogenic habitats (other methods) - Restore seagrass beds/meadows Three studies examined the effects of restoring seagrass beds (not by transplanting or translocating seagrass) on seagrass bed-associated subtidal benthic invertebrates. One was in the North Atlantic Ocean (USA), one in the Indian Ocean (Kenya), and one in the Florida Keys (USA).   COMMUNITY RESPONSE (2 STUDIES) Overall community composition (1 study): One randomized, replicated, controlled study in the Florida Keys found that restoring seagrass beds by fertilizing the seabed had no effect on overall invertebrate community composition, but adding sand led to communities different from both unrestored and natural sites. Overall species richness/diversity (2 studies): One randomized, replicated, controlled study in the Florida Keys found that after restoring seagrass beds by fertilizing the seabed and adding sand, overall invertebrate species richness was similar at restored, unrestored, and natural sites. One replicated, controlled study in the Indian Ocean found that transplanting plastic seagrass mimics into bare sites, previously-restored seagrass sites, and natural seagrass sites, resulted in similar invertebrate diversity on mimic leaves and in the surrounding sediment, and similar species richness on mimic leaves at all restored sites as on natural seagrass leaves. POPULATION RESPONSE (3 STUDIES) Overall abundance (3 studies): One replicated, randomized, controlled, before-and-after study in the North Atlantic Ocean found that after restoring seagrass beds, the abundance of mobile invertebrates had increased and was higher in restored than unrestored plots, but the abundance of sessile invertebrates had not increased. One replicated, controlled study in the Indian Ocean found that transplanting plastic seagrass mimics into bare sites, previously-restored seagrass sites, and natural seagrass sites, resulted in similar abundance of invertebrate in the surrounding sediment across sites, and resulted in different abundance of invertebrates on mimic leaves between sites although all had lower abundances than on natural seagrass leaves. One randomized, replicated, controlled study in the Florida Keys found that after restoring seagrass beds by fertilizing the seabed or adding sand, overall invertebrate abundance was not different at restored sites compared to both unrestored and natural sites. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2249https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2249Wed, 23 Oct 2019 09:45:10 +0100Collected Evidence: Collected Evidence: Translocate species - Translocate crustaceans One study examined the effects of translocating crustacean species on their wild populations. The study took place in the Tasman Sea (Australia).   COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Crustacean survival (1 study): One study in the Tasman Sea found that following translocation survival of southern rock lobsters was similar to that of resident lobsters. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2269https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2269Wed, 23 Oct 2019 12:36:49 +0100Collected Evidence: Collected Evidence: Translocate species - Translocate molluscs Nine studies examined the effects of translocating mollusc species on their wild populations. Two examined scallops in the North Atlantic Ocean (USA) and one examined scallops in the Tasman Sea and South Pacific Ocean (New Zealand). One study examined conch in the Florida Keys (USA). One examined clams in the North Atlantic Ocean (Portugal). One examined abalone in the North Pacific Ocean (USA). One examined mussels in Strangford Lough (UK). Two examined mussels in the Gulf of Corinth (Greece).   COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (8 STUDIES) Mollusc abundance (3 studies): One replicated, controlled, before-and-after study in the North Atlantic Ocean found that translocating bay scallops increased larval recruitment into the adult population compared to before translocation. One before-and-after study in the North Pacific Ocean found that following translocation of adult pink abalone to existing patchy populations, total abalone abundance (translocated and resident) decreased to similar levels as before translocation. One replicated, site comparison study in Strangford Lough found that after translocating horse mussels, the abundance of young mussels was higher in site with translocated mussels compared to both sites without translocated mussels and natural mussel reefs. Mollusc reproductive success (1 study): One replicated, controlled, before-and-after study in the North Atlantic Ocean found that translocating bay scallops did not increase larval production compared to before translocation. Mollusc survival (5 studies): Three replicated studies (one before-and-after and two site comparisons) in the North Atlantic Ocean and in the Tasman Sea and South Pacific Ocean, found that following translocation, scallops and clams survived. Survival of translocated New Zealand scallops was higher in areas closed to commercial fishing compared to fished areas. Two studies in the Gulf of Corinth found that Mediterranean fan mussels survived when translocated to a deep site, and had similar survival compared to naturally-occurring mussels, but did not survive when translocated to a shallow site. Mollusc condition (2 studies): One replicated, site comparison study in the North Atlantic Ocean found that following translocation, clams had similar condition indices to clams in the source site. One study in the Gulf of Corinth found that translocated Mediterranean fan mussels had similar size-specific growth-rates compared to naturally-occurring mussels. BEHAVIOUR (1 STUDY) Mollusc behaviour (1 study): One replicated study in the Florida Keys found that translocating non-reproductive adult queen conch to aggregations of reproductive conch did not have adverse effects on the movement patterns of non-translocated resident conch, and all conch displayed similar total distance travelled, movement rates, migration patterns, home-range sizes, and sociability. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2270https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2270Wed, 23 Oct 2019 12:38:40 +0100Collected Evidence: Collected Evidence: Tag species to prevent illegal fishing or harvesting One study examined the effects of tagging species to prevent illegal fishing or harvesting on subtidal benthic invertebrates. The study examined the effects on the Californian abalone fishery (USA).   COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOURS (1 STUDY) Behaviour-change (1 study): One before-and-after study in California found no significant reduction in non-compliance with daily quotas of abalones after introducing tagging regulations. OTHER (1 STUDY) Illegal catch (1 study): One before-and-after study in California found no significant reduction in illegal takes of abalones after introducing tagging regulations. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2275https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2275Wed, 23 Oct 2019 12:50:46 +0100Collected Evidence: Collected Evidence: Translocate mammals away from site contaminated by oil spill One study evaluated the effects of translocating mammals away from a site contaminated by oil spill. This study was in the USA. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Survival (1 study): A study in the USA found that after being translocated in a trial of responses to a hypothetical pollution incident, most sea-otters survived for the duration of monitoring. BEHAVIOUR (1 STUDY) Behaviour change (1 study): A study in the USA found that after being translocated in a trial of responses to a hypothetical pollution incident, most sea-otters did not return to their capture location. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2542https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2542Mon, 08 Jun 2020 20:32:49 +0100Collected Evidence: Collected Evidence: Set catch limits or quotas for non-targeted commercial catch Two studies examined the effects of setting catch limits or quotas for non-targeted commercial fish species on marine fish populations. One review was in the North Atlantic and Pacific Oceans and one study was in the Pacific Ocean (Canada).  COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (2 STUDIES) Reduction of unwanted catch (2 studies): One review in the Atlantic and Pacific Oceans found that setting catch limits or quotas for non-commercially targeted fish reduced unwanted catch in two of three cases. One before-and-after study in the Pacific Ocean found that catch limits for non-target commercial species reduced the amount of unwanted halibut, but a previous quota system based on the whole catch (individual transferrable quotas) did not. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2693https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2693Wed, 02 Dec 2020 16:15:52 +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: 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: Translocate mammals away from aquaculture systems to reduce human-wildlife conflict Two studies evaluated the effects of translocating mammals away from aquaculture systems to reduce human-wildlife conflict. Both studies were in the Tasman Sea and one was also in the Southern Ocean (Tasmania). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES)       OTHER (2 STUDIES) Human-wildlife conflict (2 studies): Two studies (including one site comparison study) in the Tasman Sea (one also in the Southern Ocean) found that more than half or nearly all of Australian and New Zealand fur seals translocated away from salmon farms returned. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2776https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2776Thu, 04 Feb 2021 15:43:44 +0000Collected Evidence: Collected Evidence: Set and enforce vessel speed limits Two studies evaluated the effects on marine and freshwater mammals of setting and enforcing vessel speed limits. One study was in the Indian River estuarine system (USA) and the other in the North Atlantic Ocean (USA). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (2 STUDIES) Survival (2 studies): One before-and-after study in the Indian River estuarine system found similar numbers of manatee deaths before and after vessel speed limits were set in ‘zones’, but fewer deaths were recorded after speed limits were set and enforced in all areas. One before-and-after study in the North Atlantic Ocean found that setting vessel speed limits during specific periods in key habitats resulted in fewer North Atlantic right whale deaths caused by collisions. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2777https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2777Thu, 04 Feb 2021 15:48:43 +0000Collected Evidence: Collected Evidence: Restore habitat for marine and freshwater mammals One study evaluated the effects of restoring habitat for marine mammals. The study was in the Kattegat sea (Denmark). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Abundance (1 study): One before-and-after study in the Kattegat sea found that harbour porpoise activity increased at a stony reef after it was restored with boulders and fishing was prohibited. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2920https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2920Mon, 08 Feb 2021 16:36:03 +0000Collected Evidence: Collected Evidence: Rescue and release stranded or trapped marine and freshwater mammals Eleven studies evaluated the effects of rescuing and releasing stranded or trapped marine and freshwater mammals. Five studies were in the North Atlantic Ocean (USA), two studies were in the Indian Ocean (Tasmania, South Africa), and one study was in each of the South Atlantic Ocean (Brazil), the Cachoeira River estuary (Brazil), the North Pacific Ocean (USA) and the Shannon Estuary (Ireland). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (11 STUDIES) Reproductive success (2 studies): One review in the North Pacific Ocean found that after rescuing and releasing stranded or trapped Hawaiian monk seals, along with at least seven other interventions to enhance survival, more than a quarter of the seals reproduced. One study in the Shannon Estuary found that a stranded common bottlenose dolphin that was rescued and released was observed with a calf a year later. Survival (11 studies): Seven studies (including one review) in the North Atlantic Ocean, Indian Ocean and the Shannon Estuary found that 17–100% of rescued and released Atlantic white-sided dolphins, short-beaked common dolphins, common bottlenose dolphins, long-finned pilot whales, short-finned pilot whales, and Cape fur seals survived during post-release monitoring periods, which ranged in length from three weeks to three years. Three studies in the South Atlantic Ocean, the Cachoeira estuary and the Indian Ocean found that a trapped rough-toothed dolphin, two stranded tucuxi dolphins and seven stranded sperm whales were successfully rescued and released, although long-term survival was not reported. One review in the North Pacific Ocean found that rescuing and releasing stranded or trapped Hawaiian monk seals, along with at least seven other interventions to enhance survival, resulted in more than a quarter of the seals surviving. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2924https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2924Mon, 08 Feb 2021 16:51:49 +0000Collected Evidence: Collected Evidence: Set unwanted catch quotas One study evaluated the effects of setting unwanted catch quotas on reptile populations. This study was in the USA. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Survival (1 study): One study in the USA found that following the re-opening of a swordfish long-line fishery with turtle catch limits in place, loggerhead turtle bycatch reached the annual catch limit in two of three years, and when the limit was reached the fishery was closed for the rest of the year. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3549https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3549Wed, 08 Dec 2021 12:07:09 +0000Collected Evidence: Collected Evidence: Translocate adult or juvenile reptiles: Sea turtles Two studies evaluated the effects of translocating sea turtles on their populations. One study was global and one was in Japan. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (2 STUDIES) Abundance (1 study): One global review reported that zero of four sea turtle translocations were considered successful. Reproductive success (1 study): One global review reported that zero of four sea turtle translocations found that breeding occurred. Survival (1 study): One study in Japan found that at least two of five wild-caught hawksbill turtles survived at least six months following release. BEHAVIOUR (1 STUDY) Behaviour change (1 study): One study in Japan found that at least two of five wild-caught hawksbill turtles returned to their point of capture after release. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3706https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3706Mon, 13 Dec 2021 10:47:32 +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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