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: 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: Designate a Marine Protected Area and prohibit all types of fishing Thirty studies examined the effects of prohibiting all types of fishing in marine protected areas on subtidal benthic invertebrate populations. Four studies were systematic reviews of marine reserves (New Zealand and across the world). Two studies were in the North Atlantic Ocean (Bahamas). Five were in the South Pacific Ocean (New Zealand, French Polynesia). Three were in the North Pacific Ocean (USA). Seven were in the Tasman Sea (New Zealand, Australia). One was in the Florida Keys (USA). One was in the Coral Sea (Australia). Three were in the Mediterranean Sea (Italy, Spain). One was in the Bristol Channel and the Irish Sea (UK). Two were in the Firth of Clyde (UK). One was in the Foveaux Straight (New Zealand).   COMMUNITY RESPONSE (5 STUDIES) Overall community composition (3 studies): Three site comparison studies (one replicated and paired, one replicated, one paired) in the Mediterranean Sea, the Tasman Sea, and the Firth of Clyde found that marine protected areas that had been prohibiting all fishing for five to 16 years depending on the study, had similar combined algae, invertebrate and fish community composition, similar combined mollusc and echinoderm community composition, and similar overall community composition of large invertebrates but different composition of small sessile invertebrates, compared to fished areas. Overall species richness/diversity (5 studies): One global systematic review, and three site comparison studies (one replicated and paired, one replicated, one paired) in the Mediterranean Sea, the Tasman Sea, and the Firth of Clyde found that marine protected areas that had been prohibiting all fishing for five to 16 years depending on the study, had similar overall invertebrate species richness/diversity, similar combined algae, invertebrate and fish species richness, and similar combined mollusc and echinoderm species richness, compared to fished areas. One site comparison study in the Tasman Sea found inside a marine protected area prohibiting all mobile fishing that macroinvertebrate species richness remained stable over the 15 years after its designation and enforcement, but decreased at fished sites. POPULATION RESPONSE (2 STUDIES) Overall abundance (4 studies): Two systematic reviews of marine protected areas across the world prohibiting all fishing found that they had greater overall invertebrate abundance and biomass compared to fished areas. Two site comparison studies (one before-and-after, one replicated) in the Tasman Sea found that inside marine protected areas prohibiting all fishing, overall invertebrate abundance did not change over the 15 years after their designation and enforcement and that it did not change in fished areas either, and that all areas had similar combined mollusc and echinoderm abundance after 16 years. Overall condition (1 study): One global systematic review found that in marine protected areas prohibiting all fishing, invertebrates were bigger compared to fished areas. Crustacean abundance (17 studies): Two reviews (one global and systematic, one of New Zealand areas) found that marine protected areas prohibiting all fishing had more lobsters compared to marine protected areas only partially prohibiting fishing and unrestricted fished areas. Eleven of 15 site comparison studies (including replicated, randomized, paired, before-and-after) in the North Atlantic Ocean, the Bristol Channel and the Irish Sea, the Firth of Clyde, the Mediterranean Sea, the North Pacific Ocean, the Florida Keys, the South Pacific Ocean, the Tasman Sea, and the Coral Sea found that inside marine protected areas prohibiting all fishing, the abundances and/or biomasses of lobsters and mud crabs were higher compared to areas where seasonal or unrestricted fishing was allowed, after four to 33 years depending on the study. Four found that they had mixed effects on the abundances of lobster, and crab species, after one to seven years depending on the study. Two found that they had similar abundance of lobsters compared to fished areas after either five to seven years or after approximately 30 years.  Crustacean reproductive success (4 studies): Two site comparison studies (one replicated, randomized) in the Florida Keys and the Firth of Clyde found that marine protected areas prohibiting all fishing and harvesting had similar population sex ratios of lobsters compared to where seasonal fishing or all fishing was allowed, after four to seven years depending on the study. Two replicated, site comparison studies (one randomized) in the Tasman Sea and the Mediterranean Sea found that marine protected areas prohibiting all fishing had greater lobster egg production potential compared to commercial fishing exclusion zones and fully fished areas, after either 15 years or 21 to 25 years. One site comparison study in the Firth of Clyde found that marine protected areas prohibiting all fishing had more female lobsters with eggs than fished areas, after four to seven years. Crustacean condition (8 studies): One review of studies in New Zealand, and five of seven site comparison studies (four replicated, one replicated and randomized) in the North Atlantic Ocean, the Bristol Channel and the Irish Sea, the Firth of Clyde, the Florida Keys, the South Pacific Ocean, the Coral Sea, and the Tasman Sea, found that marine protected areas prohibiting all fishing had bigger lobsters and crabs compared to seasonally fished or fully fished areas, after four to seven years depending on the study. Three found mixed effects on lobsters and crabs depending on species, sex, and locations, after one to seven years depending on the study. Crustacean population structure (2 studies): Two replicated site comparison studies (one randomized) in the Tasman Sea and the Mediterranean Sea found that marine protected areas prohibiting all fishing had different population size structures of lobsters compared to commercial fishing exclusion zones (only for females) and compared to fished areas, after either 15 years or 21 to 25 years. Echinoderm abundance (3 studies): Two of three site comparison studies (two replicated, one paired) in the North Pacific Ocean, the South Pacific Ocean, and the North Pacific Ocean, found that marine protected areas prohibiting all fishing had similar abundance of Kina sea urchins after more than 10 years, and sea cucumbers after eight years to fished areas, and a third found higher abundance of red sea urchins after approximately 30 years. One also found that the effects on abundance of red sea urchins depended on the age of the protected area and the size of the urchins. Echinoderm condition (1 study): One paired, site comparison study in the South Pacific Ocean found that marine protected areas that had been prohibiting all fishing for over 10 years had heavier Kina sea urchins compared to fished areas. Mollusc abundance (10 studies): Four of 10 site comparison studies (including replicated before-and-after, and site comparison) in the North Atlantic Ocean, the North Pacific Ocean the South Pacific Ocean, the Tasman Sea, and the Foveaux Straight found that inside a marine reserve prohibiting all fishing, abundances/biomass of giant clams, adult queen conch, Cook’s turban snails, rock scallops and green abalone were higher compared to a fished area, after eight to 36 years depending on the study. Six found similar abundances of scallop species, pink abalone, juvenile queen conch, and top shell species, after five to 36 years depending on the study. Three found lower abundances of star limpets after 23 to 25 years and blacklip abalone after 15 to 16 years. One found that the effects of marine protected areas prohibiting all fishing on the abundance of mussel species compared to a commercial fishing exclusion zone varied with the age and location of the protected areas. Mollusc reproductive success (1 study): One site comparison study in the North Atlantic Ocean found that inside a marine protected area that had been prohibiting all fishing for 33 to 36 years, abundance of queen conch larvae was higher compared to an unprotected fished area. Mollusc condition (1 study): One site comparison study in the North Pacific Ocean found that in marine protected areas that had been prohibiting all fishing pink abalone were bigger five to 23 years after their designation, compared to fished site. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2224https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2224Tue, 22 Oct 2019 14:04:19 +0100Collected Evidence: Collected Evidence: Translocate to re-establish or boost populations in native range Sixty-four studies evaluated the effects of translocating mammals to re-establish or boost populations in their native range. Twenty studies were in the USA, eight in Italy, four in Canada and South Africa, three in the Netherlands and Spain, two in each of the USA and Canada, Zimbabwe, Sweden, Australia and the USA and Mexico and one in each of Uganda, the UK, Brazil, France, Portugal, Africa, Europe, North America, Botswana, Nepal, Chile, Slovakia, Ukraine, Slovakia and Poland and one global study. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (62 STUDIES) Abundance (22 studies): Two studies (incuding one controlled and one before-and-after, site comparison study) in Spain and Canada found that translocating animals increased European rabbit abundance or American badger population growth rate at release sites. Fourteen studies (one replicated) in South Africa, the USA, the Netherlands, Italy, France and Spain found that following translocation, populations of warthogs, Eurasian beavers, red squirrels, roe deer, Alpine ibex, Iberian ibex, Cape mountain zebra, 22 species of grazing mammals, black bears, brown bear, bobcats and most populations of river otters increased. Two reviews in South Africa and Australia found that reintroductions (mainly through translocations) led to increasing populations for four of six species of large carnivores and that over half of translocations were classified as successful. One replicated study in the USA and Mexico found that translocating desert bighorn sheep did not increase the population size. Two studies (one replicated) and a review in USA and Canada, the USA and Australia found that translocated American martens, and sea otters at four of seven sites, established populations and that translocated and released captive-bred macropod species established populations in 44 of 72 cases. A study in Italy found that following the translocation of red deer, the density of Apennine chamois in the area almost halved. A worldwide review found that translocating ungulates was more successful when larger numbers were released, and small populations grew faster if they contained more mature individuals and had an equal ratio of males and females. Reproductive success (16 studies): A controlled study in Italy found that wild-caught translocated Apennine chamois reproduced in similar numbers to released captive-bred chamois. Fourteen studies (four replicated) in Canada, the USA, Zimbabwe, South Africa, the UK, Italy, the Netherlands and Slovakia found that translocated black and white rhinoceroses, warthogs, common dormice, European ground squirrels, cougars, bobcats, brown bears, sea otters, river otters and some Eurasian otters reproduced. A study in the Netherlands found that translocated beavers were slow to breed. Survival (39 studies): Four of five studies (including three controlled, two replicated and one before-and-after, site comparison study) in the USA, Canada and Chile found that wild-born translocated long-haired field mice, female elk, cougars and American badgers had lower survival rates than non-translocated resident animals. One found that translocated Lower Keys marsh rabbits had similar survival rates to non-translocated resident animals. Five of four studies (two replicated, four controlled) and two reviews in Canada, Canada and the USA, the USA, Italy, Sweden and Africa, Europe, and North America found that wild-born translocated swift foxes, European otters, black-footed ferret kits and a mix of carnivores had higher survival rates than released captive-bred animals. One study found that wild-born translocated Apennine chamois had a similar survival rate to released captive-bred animals. Twenty of twenty-one studies (including two replicated and one before-and-after study) and a review in Nepal, France, Italy, Portugal, Ukraine, Slovakia and Poland, Canada, USA, Brazil, Uganda, South Africa, Zimbabwe and Botswana found that following translocation, populations of or individual mammals survived between two months and at least 25 years. The other two studies found that two of 10 translocated white rhinoceroses died within three days of release and an American marten population did not persist. A review in Australia found that over half of translocations, for which the outcome could be determined, were classified as successful. Two of three studies (one replicated) and one review in Sweden, the UK, the Netherlands and the USA and Mexico found that following release of wild-caught translocated and captive-bred animals, European otters and common dormice survived three months to seven years. The review found that most black-footed ferret releases were unsuccessful at maintaining a population. A replicated study in the USA found that following translocation of bighorn sheep, 48–98% of their offspring survived into their first winter. Condition (3 studies): Three studies (including one replicated, controlled study) in the USA and Italy found that following translocation, populations of elk had similar levels of genetic diversity to non-translocated populations, descendants of translocated swift fox had genetic diversity at least as high as that of the translocated animals and brown bear genetic diversity declined over time. BEHAVIOUR (9 STUDIES) Use (7 studies): A study in Italy found that following translocation, Alpine ibex used similar habitats to resident animals. Two of four studies (including one randomized, controlled study) in the USA, Netherlands and Botswana found that following translocation (and in one case release of some captive-bred animals), most Eurasian otters settled and all three female grizzly bears established ranges at their release site. The other two studies found that most nine-banded armadillos and some white rhinoceroses (when released into areas already occupied by released animals) dispersed from their release site. Two studies (one replicated) in Spain found that following translocation, Iberian ibex expanded their range and roe deer increased their distribution six-fold. Behaviour change (2 studies): A replicated controlled study in Chile found that following translocation, long-haired field mice travelled two- to four-times further than non-translocated mice. A controlled study in Italy found that wild-caught translocated Apennine chamois moved further from the release site than released captive-bred animals. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2397https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2397Thu, 28 May 2020 10:46:18 +0100Collected Evidence: Collected Evidence: Use holding pens at release site prior to release of translocated mammals Thirty-five studies evaluated the effects of using holding pens at the release site prior to release of translocated mammals. Ten studies were in the USA, seven were in South Africa, four were in the UK, three studies were in France, two studies were in each of Canada, Australia and Spain and one was in each of Kenya, Zimbabwe, Italy, Ireland and India. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (31 STUDIES) Abundance (4 studies): Three of four studies (two replicated, one before-and-after study) in South Africa, Canada, France and Spain found that following release from holding pens at release sites (in some cases with other associated actions), populations of roe deer, European rabbits and lions increased in size. The other study found that elk numbers increased at two of four sites. Reproductive success (10 studies): A replicated study in the USA found that translocated gray wolves had similar breeding success in the first two years after release when adult family groups were released together from holding pens or when young adults were released directly into the wild. Seven of nine studies (including two replicated and one controlled study) in Kenya, South Africa, the USA, Italy, Ireland, Australia and the UK found that following release from holding pens at release sites (in some cases with other associated actions), translocated populations of roan, California ground squirrels, black-tailed prairie dogs, lions, four of four mammal populations, most female red squirrels and some pine martens reproduced successfully. Two studies found that one of two groups of Cape buffalo and one pair out of 18 Eurasian badgers reproduced. Survival (26 studies): Two of seven studies (five controlled, three replicated studies) in Canada, the USA, France, the UK found that releasing animals from holding pens at release sites (in some cases with associated actions) resulted in higher survival for water voles and female European rabbits compared to those released directly into the wild. Four studies found that translocated swift foxes, gray wolves, Eurasian lynx and Gunnison's prairie dogs released from holding pens had similar survival rates to those released directly into the wild. One study found that translocated American martens released from holding pens had lower survival than those released directly into the wild. Two of four studies (three controlled) in South Africa, Spain, and the USA found that translocated African wild dogs and European rabbits that spent longer in holding pens at release sites had a higher survival rate after release. One study found mixed effects for swift foxes and one found no effect of time in holding pens for San Joaquin kit foxes. Eleven studies (one replicated) in Kenya, South Africa, the USA, France, Italy, Ireland, India, Australia and the UK found that after release from holding pens at release sites (in some cases with other associated actions), translocated populations or individuals survived between one month and six years, and four of four mammal populations survived. Two studies in the UK and South Africa found that no released red squirrels or rock hyraxes survived over five months or 18 days respectively. One of two controlled studies (one replicated, one before-and-after) in South Africa and the USA found that following release from holding pens, survival of translocated lions was higher than that of resident animals, whilst that of translocated San Joaquin kit foxes was lower than that of resident animals. A study in Australia found that translocated bridled nailtail wallabies kept in holding pens prior to release into areas where predators had been controlled had similar annual survival to that of captive-bred animals. Condition (1 study): A controlled study in the UK found that translocated common dormice held in pens before release gained weight after release whereas those released directly lost weight. BEHAVIOUR (5 STUDIES) Behaviour change (5 studies): Three studies (one replicated) in the USA and Canada found that following release from holding pens, fewer translocated sea otters and gray wolves returned to the capture site compared to those released immediately after translocation, and elk remained at all release sites. Two studies in Zimbabwe and South Africa found that following release from holding pens, translocated lions formed new prides. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2434https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2434Tue, 02 Jun 2020 08:44:51 +0100Collected Evidence: Collected Evidence: Cease or prohibit all types of fishing in a marine protected area Seventy-nine studies examined the effects of ceasing or prohibiting all types of fishing in a marine protected area on fish populations. Fifteen studies were in the Indian Ocean (Kenya, Tanzania, South Africa, Mozambique, Madagascar, multiple African countries, Australia). Twelve studies were in the Mediterranean Sea (Spain, France, Italy). Ten studies were in the Pacific Ocean (New Zealand, USA, Hawaii, New Caledonia, Costa Rica, Tonga, Vanuatu, Solomon Islands). Seven studies were in each of the Coral Sea (Australia, Vanuatu), the Tasman Sea (New Zealand, Australia) and the Atlantic Ocean (Brazil, USA, Puerto Rico, Argentina, South Africa, UK, Canary Islands, Portugal, Turks and Caicos Islands). Four studies were in the Philippine Sea (Philippines). Three studies were in the Caribbean Sea (Belize, Puerto Rico). One study was in each of the Gulf of Mexico (USA), the Java Sea (Indonesia), the Pacific and Indian Oceans (multiple countries), the Sulu Sea (Malaysia) and the North Sea (Norway). Six studies were reviews of marine reserves (New Zealand, Latin America/Caribbean, regions unspecified and across the world).  COMMUNITY RESPONSE (26 STUDIES)  Community composition (7 studies): Seven site comparison studies (two replicated, and one before-and-after) in the Mediterranean Sea, Indian Ocean, Philippine Sea and the Atlantic Ocean found that protected areas where all fishing had been prohibited for between three and 16 years, had a different fish community composition, compared to fished areas.  Richness/diversity (22 studies): Fourteen of 20 site comparison studies (eight replicated, one replicated and paired, and one before-and-after) in the Indian Ocean, Mediterranean Sea, Philippine Sea, Tasman Sea, Atlantic Ocean, Caribbean Sea, Coral Sea and the Pacific Ocean, found that marine protected areas that had prohibited all fishing for between one to more than 25 years, had higher fish species/richness compared to fished areas. Six studies found similar fish species/richness between one and 20 years after all fishing was banned in protected areas, compared to fished areas. One systematic review in the Atlantic and Pacific Oceans found no difference in species richness between unfished protected areas and fished areas. One replicated, site comparison study in the Indian Ocean found that the effects of prohibiting all fishing on fish species richness/diversity after 15 years varied with the sampling method used. POPULATION RESPONSE (66 STUDIES) Abundance (64 studies): Thirty of 54 site comparison studies (18 replicated, eight replicated and paired, two before-and-after, one paired and before-and-after, and one replicated and before-and-after) in the Indian Ocean, Atlantic Ocean, Mediterranean Sea, Pacific Ocean, Tasman Sea, Coral Sea, Philippine Sea, Caribbean Sea, Gulf of Mexico, and the Sulu Sea, found that marine protected areas that had been prohibiting all fishing for up to 25 years or more, had higher abundances (density and/or biomass) of all fish (total fish biomass, total fish density), fishery targeted fish species, non-fishery targeted fish species and all or most of the individual fish species/groups monitored, except fish densities (all or most) and non-fishery targeted species, compared to unprotected fished areas and/or partly-fished protected areas. The studies also found that in some cases where the total fish biomass or densities were higher in no-fished areas, the effect varied between individual groups of fish based on species family and/or position in the food chain, commercial target and non-target species, fish sizes, depth and habitat types. Eight studies found that inside protected areas prohibiting all fishing there were similar abundances of all fish, and all or most of the individual fish species/groups monitored, compared to fished areas between one and 20 years after implementation. The other sixteen studies found that the effect of prohibiting fishing in protected areas for three to 20 years on fish abundance varied between fish species or groups and on their fished status (fishery target or non-target) and/or position in the food chain. One also found that the effect varied with size or age of the protected areas. Five of six reviews (three systematic) across the world, in the Pacific and/or Atlantic Oceans and in unreported regions found that non-fished marine reserves with one to 27 years of protection had higher abundances of all fish, all fish and invertebrates combined and blue cod compared to fished areas, but there were differences between species/groups and fishing intensity outside reserves. The other review found that fish abundance varied between species in no-take marine reserves between one and 25 years old, and was affected by food chain position, level of exploitation and duration of protection. One replicated study in the Pacific Ocean found a long-term decline in the abundance/presence of eight of 12 shark and ray species inside an established (>15 years) no-fishing protected area, however enforcement was poor. One before-and after, site comparison study in the Pacific Ocean, found no differences in overall fish abundance between a marine reserve closed permanently to fishing for five years and a closed area that was harvested for two years during the same period. One site comparison study in the Coral Sea found that in a no-take zone of an area protected for at least 10 years, fish abundance of four of six fish groups were similar to no-entry and fished zones, but two had lower abundance than the no-entry zone. One replicated, paired, site comparison study in the Tasman Sea found that in a non-fished marine park zone abundance of commercially targeted fish was higher than partly fished zones but lower than unprotected areas after four to eight years. Reproductive success (1 study): One site comparison study in the Mediterranean Sea found more eggs of four commercially targeted fish species inside a non-fished marine reserve enforced for three years than in fished areas outside the reserve. Survival (1 study): One site comparison study in the Atlantic Ocean found that prohibiting all fishing in a marine protected area for three years resulted in similar survival of red hind grouper, compared to fished areas. Condition (20 studies): Two global review studies (one systematic) and two systematic reviews in the Pacific Ocean and the Atlantic and Pacific Oceans found that prohibiting all fishing in marine protected areas for one to 27 years resulted in larger fish overall and larger blue cod compared to fished areas, but there were differences between individual fish families or species. Eight of 11 site comparison studies (four replicated, one before-and-after, one paired, and one replicated and paired) in the Tasman Sea, Pacific Ocean, Indian Ocean, Mediterranean Sea, Atlantic Ocean, Java Sea and the Philippine Sea, found that non-fished protected areas had larger fish overall and larger individuals of all or most of the fish species/groups monitored, compared to fished areas, after one to 22 years. The other three studies found similar fish sizes of all or all but one species, compared to fished areas one to 16 years after all fishing was prohibited. Three site comparison studies (one replicated) in the Coral Sea, Caribbean Sea and the Atlantic Ocean found that fish size in protected areas that had not been fished for six to more than 20 years, varied between fish species or food chain groups. One site comparison study in the Atlantic Ocean found that red hind grouper were larger, but had similar growth, in an area protected from fishing for three years compared to fished areas. One site comparison study in the Atlantic Ocean found that young lemon sharks in areas protected from fishing for 20 years had similar growth rates, but lower condition, than sharks in unprotected fished areas. BEHAVIOUR (2 STUDIES)  Behaviour change (2 studies): One replicated, site comparison study in the Pacific and Indian Oceans found that surgeonfish and parrotfish inside established protected areas where fishing was prohibited, showed a similar avoidance response to fishing gears as in fished areas, and this increased with increasing fishing intensity outside the protected areas. One replicated, site comparison study in the Indian Ocean found that in non-fished areas protected for one and 24 years, fish grazing rates were higher compared to fished areas.  OTHER (15 STUDIES) Use (7 studies): Four of six site comparison studies in the Pacific Ocean, Atlantic Ocean and the Tasman Sea found that marine protected areas where all fishing had been prohibited for at least five to 15 years, were used for a large proportion of time by shark and ray species and commercially important reef fish species, compared to fished areas, thus were provided protection from fishing. Two other studies found that time spent inside areas closed to all fishing for 20 years and over 30 years, varied between species and with size for three shark species and with size for giant trevally. One replicated study in the Indian Ocean found that most individuals of five fish species remained inside a marine reserve zone closed to fishing over a nine-year period. Catch abundance (2 studies): One of two site comparison studies in the Mediterranean Sea and Pacific Ocean found that commercial fish catch rates in small-scale traditional fisheries were highest closest to a marine reserve closed to all fishing for 22 years, and decreased with increasing distance from the reserve. The other study found that there was no increase in fish catch rates in commercially landed catch in the five years after a no-fishing zone was implemented in a co-managed protected area. Stock biomass (1 study): One replicated, site comparison study in the Indian Ocean found that the stock biomass (the harvested portion of the population) of reef fish species was highest in enforced protected areas closed to all fishing, compared to various other area management regimes.  Fishing mortality (2 studies): Two site comparison studies in the North Sea and Pacific Ocean found that prohibiting fishing in protected areas resulted in reduced commercial fishing mortality of corkwing wrasse tagged inside non-fished marine reserves compared to fished areas, and that the overall fishing mortality of grey reef sharks tagged inside protected areas was low.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2682https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2682Sat, 28 Nov 2020 14:35:06 +0000Collected Evidence: Collected Evidence: Use a larger mesh size Forty-two studies examined the effects of using a larger mesh size of fishing net on marine fish populations. Ten studies, and one review, were in the Atlantic Ocean (UK, Portugal, USA). Eight studies were in the Aegean Sea (Greece, Turkey). Five studies were in the North Sea (UK, Netherlands, France, North Europe) and three were in the Tasman Sea (Australia). Two studies were in each of the Mediterranean Sea (Italy, Turkey), the Pacific Ocean (USA, Chile), the Skagerrak and Kattegat (Northern Europe) and the Gulf of Mexico (Mexico). One study was in each of the English Channel (UK), the Bering Sea (USA), the Baltic Sea (Finland), the Caribbean Sea (Barbados), the Persian Gulf (Kuwait), the Bristol Channel (UK), the Barents Sea (Norway) and the Arabian Sea (India).  COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (3 STUDIES) Survival (3 studies): One of three controlled studies (one replicated and paired, and one replicated) in the Atlantic Ocean, Baltic Sea and Bristol Channel found that larger mesh sizes improved the post-capture survival of skates and rays compared to smaller meshes. The other two found similar post-capture survival in haddock, whiting and small herring between trawl nets with larger mesh and nets of smaller mesh size. Condition (1 study): One replicated, paired, controlled study in the Bristol Channel reported that the condition of skates and rays at capture was better with a larger trawl codend mesh size compared to a smaller mesh. BEHAVIOUR (0 STUDIES) OTHER (41 STUDIES) Reduction of unwanted catch (21 studies): Fifteen of 20 replicated studies (five controlled, two paired, eight paired and controlled, one randomized and one randomized and controlled) in the North Sea, Skagerrak/Kattegat, Aegean Sea, Caribbean Sea, Mediterranean Sea, Atlantic Ocean, Tasman Sea, Gulf of Mexico, Pacific Ocean, Bering Sea and the Bristol Channel found that using a larger mesh size in a fishing net (various trawls, gillnets, seines and trammel nets) reduced the catches of unwanted (small/undersized, non-commercial, discarded) fish or fish and invertebrates combined, compared to nets with standard/smaller mesh sizes. One study found that amounts of unwanted fish were reduced with larger mesh at smaller catch sizes but were similar between large and small meshes at larger catch sizes, and one found that increasing a trawl codend mesh size reduced the unwanted catch of one of two fish species compared to a standard mesh. Three found that larger mesh sized fishing nets did not typically reduce the unwanted fish catch compared to nets of smaller mesh sizes. One study found that increasing both the mesh size and minimum size limit reduced catches of the youngest fish. Improved size-selectivity of fishing gear (23 studies): Nineteen of 21 replicated studies (eight controlled, four paired and controlled, three randomized and controlled, and one paired) and one review, in the North Sea, Aegean Sea, Baltic Sea, Pacific Ocean, Atlantic Ocean, Gulf of Mexico, Tasman Sea, Arabian Sea, Persian Gulf, Barents Sea and the Mediterranean Sea found that larger mesh sizes (both diamond and square) of the netting of various gear types improved the size-selectivity for all fish species assessed and in one, for two of three fish species, compared to smaller mesh sizes. One study found that size-selectivity for fish was not improved with larger mesh size in the netting of fish traps. The other found that increasing the codend mesh size of trawls fitted with size-sorting escape grids resulted in similar size-selectivity of the codend for fish compared to smaller codend mesh sizes. One controlled study in the English Channel found that a trawl net codend with a larger size of square mesh had similar size-selectivity for Atlantic mackerel as a smaller diamond mesh codend. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2697https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2697Thu, 03 Dec 2020 19:56:32 +0000Collected Evidence: Collected Evidence: Use a different hook type Twenty-five studies examined the effect of using a different hook type on marine fish populations. Nine studies were in the Atlantic Ocean (Portugal, South Africa, USA, Brazil, Portugal, Iceland), six studies were in Pacific Ocean (New Zealand, Japan, Costa Rica, Hawaii, Fiji) and two studies were in the Mediterranean Sea (Spain, Italy). One study was in each of the Barents Sea (Norway), the Denmark Strait (Greenland), the Coral Sea (Australia) and the Strait of Gibraltar (Spain/Morocco). Four studies were reviews (worldwide, Atlantic and Pacific Oceans). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (10 STUDIES) Survival (10 studies): Four of seven replicated, controlled studies in the Atlantic Ocean, Pacific Ocean and Coral Sea and two of three worldwide systematic reviews, found that using different hook types in longline or recreational fisheries, including sizes, styles and other modifications to hooks, reduced the incidence of fish hook injuries (associated with higher post-release mortality), and reduced the capture mortality of some species of unwanted sharks and rays and non-target billfish species, compared to conventional hooks or other hook types. The other four studies found that using a different hook type did not reduce the post-release mortality of young sea breams, or the capture mortality of sharks species and non-target fish species, but did reduce the incidence of deep-hooking in some cases. BEHAVIOUR (0 STUDIES) OTHER (23 STUDIES) Reduction of unwanted catch (20 studies): Eight of 16 replicated studies (13 controlled, one randomized) in the Atlantic Ocean, Pacific Ocean, Barents Sea, Mediterranean Sea, Denmark Strait and Coral Sea, found that using a different hook type, including different sizes, styles and hook modifications, reduced the unwanted catch in longline and recreational hook fisheries of non-commercially targeted and targeted fish species, small non-target fish species, overall fish catch, overall discarded bony fish catch but not sharks and rays, undersized haddock, two of three unwanted fish species, non-target sharks and rays and non-target rays and sailfish, compared to standard hooks or hooks of other types. Seven studies found that changing hook type did not reduce the unwanted catch of young or non-target fish species, unwanted sharks and rays, unwanted blue shark, unwanted roughhead grenadier or non-target pelagic stingray and silky shark, compared to standard or other hook types. The other study found that catch rates of young groupers, and non-target fish and shark species varied with hook design, and larger hooks caught fewer non-target fish species overall, but more undersized grouper and sharks compared to other hook types. Four global systematic reviews found that hook style did not affect the unwanted catch of billfish species, sharks and rays or sharks, compared to standard styles. Improved size-selectivity of fishing gear (3 studies): Two of three replicated studies in the Atlantic Ocean and Strait of Gibraltar, found that increasing hook sizes improved the size-selectivity (by increasing the average catch length) of hottentot and black spot seabream compared to smaller hook sizes. The other study found that a different hook size improved size selectivity for two of five commercially targeted fish species and was also affected by bait size. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2698https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2698Tue, 08 Dec 2020 15:46:56 +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: Decrease the circumference or diameter of the codend of a trawl net Thirteen studies examined the effects of decreasing the circumference or diameter of a trawl codend on marine fish populations. Four studies were in the Tasman Sea (Australia) and three studies were in the North Sea (UK, Norway). Two studies were in the Adriatic Sea (Italy) and two were in the Baltic Sea (Denmark/ Germany). One study and one review were in the Northeast Atlantic Ocean (Northern Europe).  COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (13 STUDIES) Reduction of unwanted catch (6 studies): Two of six replicated, controlled studies (three paired, and one randomized and paired) in the Tasman Sea, Adriatic Sea and Northeast Atlantic Ocean found that bottom trawl nets of smaller circumferences reduced discarded catch of fish in three of five cases and of total discarded catch (fish and invertebrates) in one of two areas, but not overall, compared to standard trawls. Two studies found that reduced circumference codends reduced non-target or discarded fish catch in three of 12 cases and for one of four species. The two other studies found that discarded fish catch was not reduced in smaller circumference codends. Improve size-selectivity of fishing gear (8 studies): Four of eight replicated, controlled studies (one paired) in the North Sea, Adriatic Sea and Baltic Sea, and one review in the Northeast Atlantic Ocean, found that decreasing the circumference or diameter of the codend of trawl gear (bottom trawls and seines) improved the size-selectivity of haddock, Atlantic cod, whiting and European hake and red mullet, compared to larger circumferences/diameters. One also found the effect was the same across two codend mesh sizes, and one also found the effect was greater in diamond mesh with the netting orientation turned by 90° compared to standard diamond mesh. Two studies found that a decrease in codend circumference/diameter improved size-selectivity of haddock and saithe in one of two cases, and of one of three fish species. The other study found that a smaller circumference codend reduced size-selectivity of the gear for one of three fish species and was similar for the other two. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2706https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2706Thu, 17 Dec 2020 14:51:11 +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: Fit mesh escape panels/windows to a trawl net Thirty-eight studies examined the effects of fitting one or more mesh escape panels/windows to trawl nets on marine fish populations. Ten studies were in the North Sea (UK, Netherlands, Norway), four studies were in each of the Baltic Sea (Denmark, Sweden, Northern Europe), Kattegat and/or Skagerrak (Norway/Sweden/Denmark) and the Northeast Atlantic Ocean (Iceland, UK, Northern Europe). Two studies were in the Gulf of Carpentaria (Australia) and two were in the Bay of Biscay (France). One study was in each of the Irish Sea (UK), the Tasman Sea (Australia), the Bering Sea (USA), the Indian Ocean (Mozambique), the Norwegian Sea (Norway), the Pacific Ocean (Chile), the Mid-Atlantic Bight (USA), the Gulf of Maine (USA) and the Tyrrhenian Sea (Italy). Two studies were reviews (Northern Europe), and one study was in a laboratory (Japan).  COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Survival (1 study): One replicated, controlled study in the Baltic Sea found that there was no difference in survival between cod escaping from diamond mesh codends with or without square mesh escape windows. BEHAVIOUR (1 STUDY) Use (1 study): One replicated study in a laboratory found that small immature masu salmon were able to actively swim (escape) through the meshes of square mesh panels under simulated trawl conditions. OTHER (36 studies) Reduce unwanted catch (30 studies): One before-and-after study in the Baltic Sea and fourteen of 19 replicated studies (including one paired, four controlled, 10 paired and controlled, and one randomized, paired and controlled) in the North Sea, Kattegat and Skagerrak, Irish Sea, Tasman Sea, Bering Sea, Gulf of Carpentaria, Mid-Atlantic Bight, Indian Ocean, Baltic Sea, Northeast Atlantic Ocean, Bay of Biscay, Tyrrhenian Sea and the Pacific Ocean, found that square mesh escape panels/windows of varying designs and number fitted to diamond mesh trawl nets (bottom and pelagic), reduced the unwanted catches (non-target or non-marketable species/sizes) of all fish species monitored, all but one and one of four fish species, the main unwanted fish species but only two of nine other finfish, and the total unwanted/discarded catch (fish and invertebrates combined), compared to standard diamond mesh trawl nets, and the effect varied with panel/window design, position in the net and/or fish body type, as well as catch size. The other five studies and a review study of mesh escape panel/window use in the Kattegat and Skagerrak, found that square mesh panels/windows did not reduce the unwanted catches of fish, Atlantic cod and three of three commercial bottom fish species, compared to diamond mesh nets without panels/windows. Four of five replicated, controlled studies (including three paired) in the North Sea, Northeast Atlantic Ocean and Gulf of Maine, found that large diamond mesh escape panels in diamond mesh trawl nets (beam and bottom) reduced unwanted catches of cod, whiting and haddock, and discarded catch (fish and invertebrates), but not of whiting in one study, compared to nets without large diamond mesh panels, and the effect varied with panel design and vessel size. The other study found that the unwanted catches of only one of seven species/groups of non-target fish was reduced by a large diamond mesh panel. Two replicated, paired, controlled studies in the North Sea and Baltic Sea found that new or different configurations of square mesh panels/windows in diamond mesh trawl nets reduced unwanted fish and cod catches, compared to existing/standard panels or windows. One replicated, paired, controlled study in the Gulf of Carpentaria found that diamond mesh trawl nets with either a top square mesh escape panel or a large supported opening ('Bigeye') reduced unwanted shark, but not ray and sawfish catches compared to standard trawl nets. One before-and-after study in the Bay of Biscay found that supplementing a top square mesh escape window in a prawn trawl net with either a bottom window, a flexible escape grid or an increased mesh size diamond codend, did not reduce the unwanted hake catch Improved size selectivity of fishing gear (9 studies): One review study of mesh escape panel/window use in the Kattegat and Skagerrak and four of six replicated, controlled studies (including four paired) in the Baltic Sea, North Sea, northeast Atlantic Ocean, found that square mesh escape panels/windows in diamond mesh trawl nets improved the size selectivity of trawl nets for Atlantic cod and haddock, compared to trawl nets without panels/windows, and there was no difference compared to standard trawl nets with reduced mesh circumferences, and the effect varied with panel position and design. The other two studies found no effect on the size selectivity of undersized fish, haddock, saithe or Atlantic cod, compared to standard trawl nets. One review study of gear size selectivity in the northeast Atlantic Ocean found that the effect of fitting square mesh panels to trawl nets on haddock selectivity varied with panel mesh size, position, and time of year. One replicated, controlled study in the Norwegian Sea found no difference in the size selectivity of cod and haddock between diamond mesh trawl nets fitted with either square mesh escape windows, rigid size-sorting escape grids or a large diamond mesh codend. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2716https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2716Sat, 02 Jan 2021 12:18:36 +0000Collected Evidence: Collected Evidence: Fit a size-sorting escape grid (rigid or flexible) to a fish trawl net Eighteen studies examined the effects of fitting size-sorting escape grids to a fish trawl net on marine fish populations. Six studies were in the North Sea (France, Norway, Scotland), three were in the North Atlantic Ocean (Portugal, USA), and two were in the Norwegian Sea (Norway). One study was in each of the Barents Sea (Norway), the South Atlantic Ocean (Namibia), the Mediterranean Sea (Spain), the Adriatic Sea (Italy), the Gulf of Maine (USA), and the Baltic Sea (northern Europe). One study was in a laboratory (Japan).  COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (1 STUDY) Use (1 study): One replicated study in a laboratory in Japan found that masu salmon were able to actively escape through a rigid escape grid, irrespective of grid orientation and towing speed, but escape was reduced in dark conditions compared to light. OTHER (17 STUDIES) Reduction of unwanted catch (14 studies): Eleven of 14 replicated studies (three paired and controlled) in the North Sea, North Atlantic Ocean, Barents Sea, South Atlantic Ocean, Mediterranean Sea, Adriatic Sea, Gulf of Maine and Baltic Sea found that fitting size-sorting escape grids of various types and configurations to fish trawl nets reduced the catches of unwanted small mackerel, small monkfish, non-target whiting and haddock, small hake, unwanted spiny dogfish, non-target herring, prohibited halibut, unwanted sizes of cod and other non-target fish, relative to the retained codend catch or compared to trawls without grids. One study found that fitting size-sorting escape grids of three designs to fish trawl nets reduced the discarded catch of nine of 12 fish species and the overall amount of discarded catch (fish and invertebrates combined), relative to the retained codend catch. One study found that fitting size-sorting escape grids had a mixed effect on the reduction of unwanted and/or undersized fish catch relative to the retained codend catch depending on fish ecological group. The other study found that, compared to standard trawl nets without escape grids, trawls with size-sorting escape grids reduced the overall catch of whiting, but not of undersized whiting. Improved size-selection of fishing gear (3 studies): Two of three replicated studies (two paired and controlled and one controlled) in the North Sea and Norwegian Sea, found that a size-sorting escape grid fitted to trawl nets improved the size-selection of haddock, but not saithe or cod, compared to standard nets without grids. One study found that trawl nets fitted with an escape grid did not improve the size-selection of cod and haddock compared to trawl nets fitted with square mesh escape windows. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2720https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2720Fri, 08 Jan 2021 16:54:19 +0000Collected Evidence: Collected Evidence: Fit a size-sorting escape grid (rigid or flexible) to a prawn/shrimp trawl net Thirty studies examined the effects of fitting size-sorting escape grids to prawn/shrimp trawl nets on marine fish populations. Five studies were in the North Sea (Scotland/Norway, Belgium/Netherlands, UK, Scotland), four were in the Coral Sea (Australia) and two were in each of the Gulf of Carpentaria (Australia), the Indian Ocean (Australia, Mozambique), the North Atlantic Ocean (Portugal, USA), the Pacific Ocean (Chile, USA), the Skagerrak and Kattegat (northern Europe) and the South Atlantic Ocean (Brazil). One study was in each of the Tasman Sea (Australia), the Greenland Sea (Svalbard), the Bay of Biscay (France), the Gulf of Maine (USA), the Gulf of Thailand (Vietnam), the Tyrrhenian Sea (Italy), the Gulf of St Vincent (Australia), the Persian Gulf (Iran) and the Northeast Atlantic Ocean (Norway). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (30 STUDIES) Reduction of unwanted catch (30 studies): Seven of seven replicated studies (including one controlled) in the northeast Atlantic Ocean, North Sea, North Atlantic Ocean, Greenland Sea, Gulf of Thailand, Tyrrhenian Sea and the Skagerrak and Kattegat found that fitting rigid or flexible size-sorting escape grids, of various types and configurations, to prawn/shrimp trawl nets reduced unwanted fish catches (non-commercial species and discarded commercial species/sizes) by allowing the escape of unwanted sharks and the other fish species monitored. Two of two before-and-after studies in the Gulf of Maine and Pacific Ocean found that after the introduction of size-sorting escape grids to trawl nets in fisheries for shrimp, the capture of non-target and unwanted fish was reduced compared to before grids were used. Eleven of 20 replicated studies (including one controlled and 19 paired and controlled) in the Tasman Sea, Coral Sea, Gulf of Carpentaria, North Sea, Indian Ocean, Bay of Biscay, Skagerrak and Kattegat, Pacific Ocean, South Atlantic Ocean, Gulf of St Vincent and Persian Gulf found that prawn/shrimp trawls with size-sorting escape grids, of various types and configurations, had lower catches of all or all but one undersized or otherwise unwanted fish and shark/ray species monitored, and unwanted total catch (fish and invertebrates), compared to trawl nets without escape grids. Two found that escape grids reduced non-target catches of most sizes of whiting and plaice and larger sizes of total fish, but increased the retention of small cod and haddock. Three studies found a variable effect of fitting escape grids to shrimp/prawn trawl nets on unwanted fish catch compared to nets with no grids, and the effect varied with year, site and grid type. Three found that grids had no effect on the reduction of unwanted fish and catches were similar for all or most of the unwanted non-commercial and commercial fish species/groups and for the total unwanted catch (fish and invertebrates). The other study found that fewer unwanted fish of 10 of 11 species/groups were retained in a shrimp/prawn trawl net with an escape grid used in combination with a diamond mesh codend with the mesh orientation turned by 90°, compared to a conventional diamond mesh net with no grid. One replicated, randomized study in the North Atlantic Ocean found that the reduction in catch of unwanted sharks depended on the type of escape grid and shrimp/prawn trawl net used. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2721https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2721Mon, 18 Jan 2021 16:42:48 +0000Collected Evidence: Collected Evidence: Use a different design or configuration of size-sorting escape grid/system in trawl fishing gear (bottom and mid-water) Twenty-three studies examined the effects of using a different design or configuration of size-sorting escape grid/system in trawl fishing gear on marine fish populations. Ten studies were in the Atlantic Ocean (Canada, USA, Brazil, Spain, Norway). Five studies were in the Barents and/or Norwegian Sea (Norway). Two studies were in the Kattegat and Skagerrak (Denmark/Sweden). One study was in each of the Arafura Sea (Australia), the Greenland Sea (Norway), the North Sea (Norway), the North Pacific Ocean (USA) and the Indian Ocean (Australia). One study was in a laboratory (Japan).  COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) OTHER (23 STUDIES) Reduction of unwanted catch (17 studies): Six of 16 replicated studies (eight paired and controlled, three controlled, one randomized and controlled, and one paired) in the Atlantic Ocean, a laboratory, Arafura Sea, Barents Sea, Kattegat and Skagerrak, Greenland Sea, North Sea, Pacific Ocean and the Indian Ocean, and one controlled study in the Barents Sea found that using a different design or configuration of size-sorting escape grid/system in trawl nets reduced the unwanted (undersized, non-target, discarded) catches of all or most of the fish species assessed, compared to standard or other grid designs/configurations. Four studies found that the effect of using different escape grids on the reduction of unwanted catch varied with fish species, light conditions, and the type of trawl net used. The other six found that, overall, using a different escape grid did not reduce unwanted fish catch. Improve size-selectivity of fishing gear (7 studies): Three of seven replicated studies (three controlled, one paired and controlled) in the Barents/Norwegian Sea, the Atlantic Ocean and the Greenland Sea found that different types or configurations of size-sorting escape grid systems in trawl nets resulted in better size-selectivity for unwanted redfish and Greenland halibut and of commercial target hake compared to other designs or configurations. Three studies found that the effect of using a different design or configuration of size-sorting escape grid/system on improving the size-selectivity of trawls varied between fish species compared to standard or other escape grid designs. The other study found that a new design of grid system did not improve the size-selectivity of unwanted redfish compared to an existing system. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2728https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2728Mon, 25 Jan 2021 16:30:19 +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: Rehabilitate and release injured, sick or weak marine and freshwater mammals Twenty-seven studies evaluated the effects of rehabilitating and releasing injured, sick or weak marine and freshwater mammals. Nine studies were in the North Atlantic Ocean (USA, UK, France), six studies were in the North Pacific Ocean (USA), four studies were in the Gulf of Mexico (USA), two studies were in each of the North Sea (the Netherlands) and the Gulf of Maine (USA), and one study was in each of the Indian River Lagoon (USA), Bohai Bay (China), The Wash estuary (UK), water bodies in Florida (USA), El Dorado Lake (Peru), and the Gulf of California (Mexico). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (26 STUDIES) Reproductive success (1 study): One replicated study in the North Pacific Ocean found that more than a quarter of rehabilitated and released Hawaiian monk seals reproduced. Survival (26 studies): Twenty-one studies (including two controlled studies, four replicated studies and one review) in the North Atlantic Ocean, the Gulf of Maine, the Gulf of Mexico, the North Pacific Ocean, the Indian River Lagoon, The Wash estuary, water bodies in Florida, El Dorado Lake, and the Gulf of California found that 10–100% of dolphins, porpoises, whales, seals, sea lions and manatees released after rehabilitation in captivity survived during post-release monitoring periods, which ranged in length from three days to five years. Five studies (including one replicated study) in the North Sea, the North Atlantic Ocean, Bohai Bay and the North Pacific Ocean found that two of three harbour porpoises, 152 of 188 grey seal pups, a common seal, a west Pacific finless porpoise and 14 of 35 California sea lions were successfully rehabilitated and released but survival after release was not reported. One controlled study in the North Pacific Ocean found that at least a quarter of California sea lions treated for toxic algae poisoning and released back into the wild died or had to be euthanized. BEHAVIOUR (3 STUDIES) Behaviour change (3 studies): Two of three controlled studies in the North Atlantic Ocean, the North Pacific Ocean and The Wash estuary found that a harbour porpoise and six harbour seals that were rehabilitated and released had similar movements and/or behaviours to wild mammals. The other study found that California sea lions treated for toxic algae poisoning and released travelled further from the shore, spent less time diving or hauled out and made shorter, shallower dives than wild sea lions without poisoning. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2925https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2925Mon, 08 Feb 2021 16:57:11 +0000Collected Evidence: Collected Evidence: Directly plant non-woody plants: brackish/saline wetlands Thirty studies evaluated the effects, on vegetation, of directly planting emergent, non-woody plants in brackish/saline wetlands. Twenty-four studies were in the USA. There was one study in each of Canada, New Zealand, Spain, Italy and Australia. One study was a global systematic review. Four of the studies monitored different outcomes of one planting experiment in California. Two other studies used the same marsh as each other. Two studies shared some plots with each other. VEGETATION COMMUNITY Community composition (1 study): One replicated, site comparison study around fresh/brackish lakes in Australia reported that as planted rush stands aged, their near-shore plant community became more similar to that behind mature natural rush stands. Overall richness/diversity (3 studies): One controlled study on a brackish sandflat in the USA reported that an area planted with wetland herbs contained more plant species, after eight years, than an adjacent unplanted area. One replicated, site comparison study around fresh/brackish lakes in Australia found that the near-shore vegetation behind >8-year-old planted rush stands and mature natural stands contained a similar number of plant species. One study of a fresh/brackish/saline marsh in Italy simply quantified plant species richness for up to 13 years after planting herbs (along with other interventions). VEGETATION ABUNDANCE Overall abundance (4 studies): Two site comparison studies (one replicated) of brackish/saline marshes in the USA reported that areas planted with herbs (sometimes along with other interventions) contained less vegetation, after 2–3 growing seasons, than nearby natural marshes. This was true for biomass and cover. One replicated, site comparison study around fresh/brackish lakes in Australia found that the density of near-shore vegetation behind older planted rush stands was similar to that behind mature natural stands. One replicated, randomized, paired, controlled study in an estuary in the USA reported that plots planted with salt marsh vegetation contained more vegetation biomass than unplanted plots, after three growing seasons. Individual species abundance (18 studies): Eighteen studies quantified the effect of this action on the abundance of individual plant species. Four studies in the USA compared the abundance of plant species in planted and unplanted areas. Two replicated studies found that planted herb species were typically more abundant in planted than unplanted plots, after 2–4 growing seasons. One replicated, paired, controlled study reported that there were fewer common reed Phragmites australis stems in plots planted with other wetland herbs (and shrubs) than in unplanted plots, after 1–3 years. One replicated, randomized, controlled study reported species-specific effects of planted individuals on recruitment of conspecific seedlings. Nine studies in the USA and Australia compared the abundance of herb species where they had been planted to their abundance in natural brackish/saline marshes. Results varied between studies, species, metrics and time since planting. One before-and-after study of an intertidal site in the USA reported greater abundance of smooth cordgrass Spartina alterniflora over five years after planting (along with other interventions) than before. Seven studies (six replicated) in brackish/saline marshes in the USA and Canada simply quantified the abundance of individual species over 1–3 growing seasons after they were planted (sometimes along with other interventions). VEGETATION STRUCTURE Overall structure (2 studies): One replicated, randomized, paired, controlled, site comparison study in a salt marsh in the USA found that plots planted with herbs contained more canopy layers than unplanted plots after 2–4 growing seasons. One replicated, site comparison study around fresh/brackish lakes in Australia reported that as planted rush stands aged, their width increased – becoming more similar to mature natural stands. Height (11 studies): Three replicated studies in salt marshes in the USA found that vegetation in areas planted with herbs was at least as tall as vegetation in unplanted areas, 2–4 growing seasons after planting. Of six site comparison studies that compared vegetation height in planted and natural marshes (sometimes along with other interventions), three studies in the USA reported that vegetation was shorter in planted marshes after 2–5 growing seasons. Two studies in the USA and Australia found that vegetation was typically a similar height in planted and natural marshes after 2–11 years. One study in the USA found that vegetation was taller in planted marshes after three growing seasons. Four replicated studies in brackish/saline marshes in the USA simply quantified the height of herbs over 1–5 growing seasons after they were planted; in three of these studies, the average height increased over time. OTHER Survival (17 studies): Seventeen studies (including 13 replicated and one systematic review) in the USA, Canada, New Zealand, Spain and multiple countries quantified survival rates of individual herbs planted (or sown) in brackish/saline wetlands. Survival rates ranged from 0% to 100% after 20 days to 2 years. Four studies in the USA, New Zealand and multiple countries reported 0% survival or absence of planted herb species, in at least some cases, after nine months to eight years. Proposed factors affecting survival included elevation/water levels, age of planted individuals, treatment with root dip, planting date, soil pH, damage by waterbirds, salinity and sediment organic matter content. Growth (2 studies): Two studies monitored true growth of individual herbs (rather than changes in average height of survivors). One replicated study in a brackish marsh in the USA reported that in 8 of 10 cases, rushes/bulrushes grew in both height and circumference over the second year after planting. One replicated study in an estuary in Spain reported growth of planted small cordgrass Spartina maritima and glasswort Sarcocornia perennis over the year after planting. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3257https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3257Sat, 10 Apr 2021 13:27:23 +0100Collected Evidence: Collected Evidence: Directly plant trees/shrubs: brackish/saline wetlands Forty-seven studies evaluated the effects, on vegetation, of directly planting trees/shrubs in brackish/saline wetlands. Forty-four studies involved planting mangroves or other coastal swamp trees: 20 in Asia, seven in Central America, six in Africa, four in North America, four in South America, two in Oceania and one globally. Three studies involved planting shrubs in the USA or Spain. There was overlap in the sites used in two studies. One systematic review included several of the other summarized studies. VEGETATION COMMUNITY Overall extent (3 studies): Two before-and-after studies in India and South Africa reported that the area of mangrove forest was greater 6–42 years after planting mangrove trees (sometimes along with other interventions) than in the years before. One study in Sri Lanka simply quantified the area of mangrove vegetation present 8–10 years after planting seedlings (and propagules). Tree/shrub richness/diversity (6 studies): Three site comparison studies in the USA, Mexico and Brazil reported that where mangrove forests developed after planting trees (sometimes along with other interventions), they contained a similar number of tree species to mature and/or naturally regenerating forests after 10–30 years. One site comparison study in Vietnam reported that after 14–34 years, a planted mangrove forest contained more tree species than a (slightly older) naturally regenerated forest. One replicated, paired, before-and-after, site comparison study in Kenya reported that planted mangrove forest contained fewer adult tree species than mature natural forest after five years, but more species of seedling. One study in a former shrimp pond in Thailand simply reported the number of unplanted tree species that had colonized six years after planting (along with other interventions). VEGETATION ABUNDANCE Tree/shrub abundance (9 studies): Three replicated, site comparison studies of coastal sites in the Philippines, the USA and Brazil reported that where mangrove forests developed after planting trees (sometimes along with other interventions), woody vegetation was typically more dense than in mature natural forests and/or naturally regenerating forests. Two site comparison studies in Kenya and Vietnam found that tree abundance (density and biomass) was similar in planted and natural mangroves after 5–34 years. One site comparison study in Mexico reported that a planted mangrove forest contained fewer trees than pristine natural forests after 12 years. Two site comparison studies in the Philippines reported mixed results according to time since planting and site. One study in Thailand simply quantified the abundance of mangrove trees six years after planting (along with other interventions). Algae/phytoplankton abundance (1 study): One site comparison study in Kenya found that mangrove forests restored by planting contained a similar algal biomass, after eight years, to mature natural forests. However, mangrove forests created by planting into bare sediment contained less algal biomass than mature natural forests. Individual species abundance (7 studies): Seven studies quantified the effect of this action on the abundance of individual plant species. Four of the studies compared the abundance of woody vegetation or algae in planted mangrove forests and mature natural forests – and sometimes naturally regenerating forests (see original papers for data). One replicated, paired, controlled study in a brackish wetland in the USA reported that there were fewer common reed Phragmites australis stems in plots planted with wetland shrubs (and herbs) than in unplanted plots, after 1–3 years. One before-and-after study of an intertidal site in the USA reported greater abundance of red mangrove Rhizophora mangle over five years after planting (along with other interventions) than before. VEGETATION STRUCTURE Overall structure (3 studies): Three replicated, site comparison studies of coastal sites in the Kenya, the USA and the Philippines reported that where mangrove forests developed after planting trees (sometimes along with other interventions), their overall structure differed from mature natural forests for up to 50 years. Height (18 studies): Four site comparison studies (three replicated, three paired) of coastal sites in Kenya, the USA, Brazil and the Philippines reported that where mangrove forests developed after planting trees (sometimes along with other interventions), the vegetation was shorter than in mature and naturally regenerating forests after 5–30 years. One site comparison study in Mexico reported that planted mangrove forests contained taller trees than pristine natural forests after 12 years. Fourteen studies (four replicated) in Asia, Central/South America, Africa and North America simply quantified the height of mangrove trees for up to six years after they were planted; in 13 of these studies, the average height increased over time. Diameter (7 studies): Two site comparison studies in Mexio and Vietnam reported that tree diameters were similar in planted and natural mangroves after 12–34 years. In contrast, two site comparison studies in Brazil and the Philippines reported that planted mangroves contained thinner tree stems than mature natural mangroves after 7–12 years. The study in Brazil also reported that stem diameters were thinner than in naturally regenerating areas. Three studies in India and Nigeria simply quantified the diameter of mangrove trees for up to three years after they were planted; in all three studies, the average stem diameter increased over time. Basal area (3 studies): Two site comparison studies (one also replicated, paired, before-and-after) in Kenya and Mexico reported that planted mangrove forests had a smaller basal area than mature natural forests after 5–12 years. One replicated, site comparison study in the USA reported that where mangrove forests developed after planting trees (along with other interventions), their basal area was similar to mature natural forests after 17–30 years. OTHER Survival (37 studies): Thirty-six studies (including one review and one systematic review) quantified survival rates of individual trees/shrubs planted in brackish/saline wetlands. Survival rates ranged from 0% to 100% after 15 days to 21 years. The studies were of mangroves in North America, Central/South America, Asia, Africa, Oceania or globally, and of shrubs in the USA or Spain. Six studies reported 100% survival in some cases. Eleven studies reported 0% survival or absence of planted species in some cases. In six studies, survival of planted seedlings was not distinguished from survival of seeds or propagules. Proposed factors affecting survival included elevation/water levels, exposure to wind/waves, soil properties, sediment deposition, oyster/barnacle colonization, salinity, use of guidance and post-planting care. Growth (9 studies): Nine studies monitored true growth of individual trees/shrubs (rather than changes in average height of survivors). The nine studies, in Colombia, the USA, the Philippines, Brazil and China, reported that planted trees/shrubs typically grew, over periods from 40 days to 50 years. One replicated study in the USA reported that planted seedlings grew less quickly than naturally colonizing seedlings. One replicated, site comparison study in the Philippines found that growth rates of trees in planted mangroves became more similar to those in mature natural mangroves over time. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3259https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3259Sat, 10 Apr 2021 13:27:43 +0100Collected Evidence: Collected Evidence: Introduce tree/shrub seeds or propagules: brackish/saline wetlands Nineteen studies evaluated the effects, on vegetation, of introducing seeds or propagules of trees/shrubs to brackish/saline wetlands. All 19 studies involved planting mangrove propagules: seven in Asia, five in North America, three in Central America, two in Oceania, one in South America and one globally. Three studies in the USA shared some study sites. VEGETATION COMMUNITY Overall extent (2 studies): Two studies in the USA and Sri Lanka simply quantified the area of mangrove vegetation present 6–14 years after planting propagules (along with other interventions). Relative abundance (1 study): One replicated, paired, site comparison study in the USA reported that mangrove forests created by planting propagules (after reprofiling) supported a different relative abundance of tree species to natural forests, after 7–15 years. Tree/shrub richness/diversity (2 studies): Two replicated, site comparison studies in the USA reported that mangrove forests created by planting propagules (along with other interventions) contained a similar number of tree species to mature natural forests, after 7–30 years. VEGETATION ABUNDANCE Tree/shrub abundance (3 studies): Three replicated, site comparison studies of coastal sites in the USA and the Philippines reported that where mangrove forests developed after planting propagules (along with other interventions), trees were typically more dense than in mature natural forests. VEGETATION STRUCTURE Overall structure (1 study): One replicated, site comparison study in the USA reported that mangrove forests created by planting propagules (along with other interventions) had a different overall physical structure to mature natural forests, after 17–30 years. Height (4 studies): Four studies (three replicated) in Thailand, the USA, Mexico and the United Arab Emirates simply quantified the height of surviving mangrove trees for up to 16 years after sowing seeds or planting propagules; in all of these studies, the average height increased over time. Diameter/perimeter/area (3 studies): Two site comparison studies (one also replicated and paired) in the USA reported that mangrove forests created by planting propagules (after reprofiling) contained thinner trees, on average, than mature natural forests, after 7–18 years. One study in a coastal area planted with mangrove propagules in Thailand reported that the average diameter of surviving seedlings increased over time. Basal area (3 studies): Three site comparison studies (two also replicated, one also paired) in the USA compared mangrove forests created by planting propagules (along with other interventions) and mature natural forests. Two of the studies reported that planted forests had a smaller basal area than mature natural forests, after 7–18 years. The other study reported that planted forests had similar basal area to mature natural forests, after 17–30 years. OTHER            Germination/emergence (2 studies): One replicated study in the United Arab Emirates reported 65–92% germination of sown grey mangrove Avicennia marina seeds, across five coastal sites. One replicated study in a brackish/saline estuary in China reported 38–100% germination of planted mangrove propagules, depending on the species and habitat. Survival (16 studies): Fifteen studies quantified survival of individual tree/shrub propagules planted in brackish/saline wetlands (or plants originating from them). All 15 studies were of mangroves: in Central/South America, Asia, North America, Oceania or gloablly. All reported survival in at least some cases, from 20 days to 30 years after planting. Five studies reported 100% survival in some cases. However, nine studies reported 0% survival or absence of planted species in some cases. In five studies, survival of seeds or propagules was not distinguished from survival of planted seedlings. Proposed factors affecting survival rates included elevation/water levels, substrate, invertebrate herbivory, use of tree shelters, mechanical stress, oyster colonization, use of guidance, post-planting care and repeated planting. Growth (5 studies): Five studies monitored true growth of individual trees/shrubs (rather than changes in average height of survivors). All five studies (three replicated) in Australia, the USA, Colombia and the Philippines reported that mangrove seedlings, originating from planted seeds or propagules, grew over time. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3267https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3267Sat, 10 Apr 2021 15:36:07 +0100Collected 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 +0000
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What Works in Conservation

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

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