Collected Evidence: Collected Evidence: Cease or prohibit all types of fishing Five studies examined the effects of ceasing or prohibiting all types of fishing on subtidal benthic invertebrate populations. All studies were in the North Sea (Belgium, Germany, Netherlands, UK).   COMMUNITY RESPONSE (2 STUDIES) Overall community composition (2 studies): Two site comparison studies (one before-and-after) in the North Sea found that areas closed to all fishing developed different overall invertebrate community compositions compared to fished areas. Overall species richness/diversity (2 studies): One of two site comparison studies (one before-and-after) in the North Sea found that areas closed to all fishing did not develop different overall invertebrate species richness and diversity compared to fished areas after three years, but the other found higher species richness in the closed areas after 20 years. POPULATION RESPONSE (3 STUDIES) Overall abundance (2 studies): Two site comparison studies (one before-and-after) in the North Sea found that areas closed to all fishing had similar overall invertebrate abundance and biomass compared to fished areas after three and five years. Crustacean abundance (1 study): One before-and-after, site comparison study in the North Sea found that closing a site to all fishing led to similar numbers of lobster compared to a fished site after 20 months. Crustacean condition (1 study): One before-and-after, site comparison study in the North Sea found that closing a site to all fishing led to larger sizes of lobster compared to a fished site after 20 months. OTHER (1 STUDY) Overall community energy flow (1 study): One before-after, site comparison study in the North Sea found that, during the 12–14 months after closing an area to all fishing, the invertebrate community structure (measured as energy flow) at sites within the closed area did not change, but that it increased in nearby fished sites. Species energy flow (1 study): One before-and-after, site comparison study in the North Sea found that closing an area to all fishing for 12–14 months had mixed effects on species-level energy flow. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2096https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2096Mon, 21 Oct 2019 15:32:10 +0100Collected Evidence: Collected Evidence: Establish temporary fisheries closures Six studies examined the effects of establishing temporary fisheries closures on subtidal benthic invertebrates. One study was in the English Channel (UK), one in the D’Entrecasteaux Channel (Australia), one in the North Pacific Ocean (USA), two in the Mozambique Channel (Madagascar), and one in the North Sea (UK).   COMMUNITY RESPONSE (2 STUDIES) Overall species richness/diversity (1 study): One replicated, site comparison study in the English Channel found that sites seasonally closed to towed-gear fishing did not have greater invertebrate species richness than sites where towed-fishing occurred year-round. Mollusc community composition (1 study): One replicated, before-and after study in the D’Entrecasteaux Channel found that temporarily reopening an area previously closed to all fishing for 12 years only to recreational fishing led to changes in scallop species community composition over four fishing seasons. POPULATION RESPONSE (1 STUDY) Overall abundance (1 study): One replicated, site comparison study in the English Channel found that sites seasonally closed to towed-gear fishing did not have a greater invertebrate biomass than sites where towed-fishing occurred year-round. Crustacean abundance (1 study): One before-and-after, site comparison study in the North Sea found that reopening a site to fishing following a temporary 20-month closure led to lower total abundance but similar marketable abundance of European lobsters compared to a continuously-fished site after a month. Mollusc abundance (5 studies): One replicated, site comparison study English Channel found that sites seasonally closed to towed gear did not have higher abundance of great scallops than sites where towed-fishing occurred year-round. Two before-and after, site comparison studies (one replicated) in the Mozambique Channel found that temporarily closing an area to reef octopus fishing did not increase octopus abundance/biomass compared to before closure and to continuously fished areas. Two replicated, before-and after studies in the D’Entrecasteaux Channel and the North Pacific Ocean found that temporarily reopening an area previously closed to all fishing to recreational fishing only led to a decline in scallop abundance after four fishing seasons and in red abalone after three years. Mollusc condition (3 studies): One replicated, before-and after study in the North Pacific Ocean found that temporarily reopening an area previously closed to fishing led to a decline in the size of red abalone after three years. Two before-and after, site comparison studies (one replicated) in the Mozambique Channel found that temporarily closing an area to reef octopus fishing increased the weight of octopus compared to before closure and to continuously fished areas, but one also found that this effect did not last once fishing resumed. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2098https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2098Tue, 22 Oct 2019 08:34:46 +0100Collected Evidence: Collected Evidence: Modify the design of dredges Six studies examined the effects of modifying the design of dredges on subtidal benthic invertebrate populations. Four were in the North Atlantic Ocean (Portugal) and two were in the Irish Sea (Isle of Man).   COMMUNITY RESPONSE (1 STUDY) Unwanted catch overall composition (1 study): One replicated, controlled, study in the Irish Sea found that a new design of scallop dredge caught a similar species composition of unwanted catch to a traditional dredge. POPULATION RESPONSE (3 STUDIES) Overall abundance (2 studies): One of two controlled studies in the North Atlantic Ocean and in the Irish Sea found that a new dredge design damaged or killed fewer invertebrates left in the sediment tracks following dredging. The other found no difference in total invertebrate abundance or biomass living in or on the sediment tracks following fishing with two dredge designs. Unwanted catch overall abundance (2 studies): Two controlled studies (one replicated) in the North Atlantic Ocean and the Irish Sea found that a modified or a new design of bivalve dredge caught less unwanted catch compared to traditional unmodified dredges. Unwanted catch condition (6 studies): Six controlled studies (one replicated and paired, four replicated) in the North Atlantic Ocean and the Irish Sea found that new or modified bivalve dredges damaged or killed similar proportions of unwanted catch (retained and/or escaped) compared to traditional or unmodified designs, three of which also found that they did not reduce the proportion of damaged or dead unwanted crabs (retained and/or escaped). OTHER (1 study) Commercial catch abundance (1 study): One replicated, controlled, study in the Irish Sea found that a new dredge design caught a similar amount of commercially targeted queen scallops compared to a traditional dredge. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2119https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2119Tue, 22 Oct 2019 09:59:43 +0100Collected Evidence: Collected Evidence: Fit one or more mesh escape panels/windows to trawl nets Seven studies examined the effects of adding one or more mesh escape panels/windows to trawl nets on subtidal benthic invertebrate populations. Six were in the North Sea (Belgium, Netherlands, UK), two in the Thames estuary (UK), one in the English Channel (UK), and one in the Gulf of Carpentaria (Australia).   COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (7 STUDIES) Overall survival (1 study): One replicated, paired, controlled study in the English Channel and the North Sea found that fitting nets with either one of seven designs of square mesh escape panels (varying mesh size and twine type) led to higher survival rates of invertebrates that escaped the nets compared to unmodified nets. Unwanted catch overall abundance (7 studies): Three of seven replicated, paired, controlled studies in the North Sea, the Thames estuary, the English Channel and the Gulf of Carpentaria  found that trawl nets fitted with one or more mesh escape panels/windows/zones reduced the unwanted catch of invertebrates compared to unmodified nets. Two found mixed effects of fitting escape panels on the unwanted catch of invertebrates and fish depending on the panel design. Two found that trawl nets fitted with escape panels  caught similar amounts of unwanted invertebrates and fish compared to unmodified nets. OTHERS (7 STUDIES) Commercially targeted catch abundance (7 studies): Three of seven replicated, paired, controlled studies in the North Sea, the Thames estuary, the English Channel and the Gulf of Carpentaria, found that trawl nets fitted with one or more mesh escape panels/windows/zones caught similar amounts of all or most commercial species to unmodified nets. Three found mixed effects of fitting escape panels on the catch of all or most commercial species depending on the species and/or panel design. One found that trawl nets fitted with escape panels reduced the catch of commercial species compared to unmodified nets. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2132https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2132Tue, 22 Oct 2019 10:33:29 +0100Collected Evidence: Collected Evidence: Restore biogenic habitats (other methods) - Restore oyster reefs Eight studies examined the effects of restoring oyster reefs (not by transplanting or translocating oysters) on oysters and oyster reef-associated subtidal benthic invertebrates. Two were in the Gulf of Mexico (USA), one was a global review, four were in the North Pacific Ocean (USA), and one was in the Mission-Aransas estuary (USA).   COMMUNITY RESPONSE (3 STUDIES) Overall community composition (2 studies): One of two replicated, controlled studies in the Gulf of Mexico and the Mission-Aransas estuary found that after restoring eastern oyster reefs, the community composition of combined mobile decapod invertebrates and fish was similar on all types of restoration material used, but the other found that composition varied with the material used. Overall species richness/diversity (3 studies): One replicated, site comparison study in the Gulf of Mexico found that diversity of reef-associated invertebrates was similar in reefs restored by laying rocks regardless of age, in young reefs restored by laying oyster shells, and in natural reefs, but lower in old shell-restored reefs. One replicated, controlled study in the Gulf of Mexico found that diversity of reef-associated invertebrates was higher in all restored reefs than on unrestored sediment, but that diversity varied between the restoration materials used. One replicated, controlled study in the Mission-Aransas estuary found that diversity of fish, crabs and shrimps varied with the restoration material used. POPULATION RESPONSE (7 STUDIES) Overall abundance (2 studies): One replicated, site comparison study in the Gulf of Mexico found that the effect of restoring eastern oyster reefs on the abundance of reef-associated invertebrates depended on the material used for restoration and the age of the reef. One replicated, controlled study in the Gulf of Mexico found that abundance of combined reef-associated mobile decapod invertebrate and fish was similar on all restored reefs regardless of the restoration material used, and higher than on unrestored sediment. Crustacean abundance (1 study): One replicated, controlled study in the Mission-Aransas estuary found that after restoring eastern oyster reefs, crab abundance, but not biomass, and shrimp biomass, but not abundance, varied with the restoration material used. Oyster abundance (6 studies): One replicated, site comparison study in the Gulf of Mexico found that oyster reefs restored by laying rocks had similar oyster abundance to natural reefs, and higher than reefs restored by laying oyster shells. One replicated, controlled study in the Mission-Aransas estuary found that oyster cover and abundance varied with the restoration material used. One replicated, controlled study in the Gulf of Mexico found that oyster spat abundance was similar on all types of restoration material used, and higher than on unrestored sediment. Three replicated, controlled studies in the North Pacific Ocean found that restoring oyster reefs by placing lines of clam shells below Mean Lower Low Water (MLLW) led to higher cover of clam shells by oysters than when placing the lines above MLLW, that for those placed below MLLW, keeping them there led to similar cover compared to moving them above MLLW halfway through the study, and that placing the lines on cobbly seabed led to similar cover compared to placing them on muddy seabed. Oyster reproductive success (3 studies): Three replicated, controlled studies in the North Pacific Ocean found that restoring oyster reefs by placing lines of clam shells below Mean Lower Low Water (MLLW) led to higher recruitment of oyster spat on clam shells than by lacing lines above MLLW, that recruitment was higher on lines placed on cobbly seabed than on muddy seabed, and that recruitment was similar on lines placed near or far from the nearest adult oyster populations. Oyster survival (5 studies): One global systematic review found that two of nine restoration techniques (restoring oyster reef by transplanting juveniles, and by creating no-harvest sanctuaries) assessed resulted in over 85% survival of restored oysters. Four replicated, controlled studies in the North Pacific Ocean found that restoring oyster reefs by placing lines of clam shells below Mean Lower Low Water (MLLW) led to similar survival of oysters than when placing the lines above MLLW, but that for those placed below MLLW, moving them above MLLW halfway through the study led to higher survival than keeping then below, that survival was similar on lines placed on cobbly seabed or muddy seabed, and that survival was similar on lines placed near or far from the nearest adult oyster populations. Oyster condition (5 studies): One replicated, controlled study in the Gulf of Mexico found that the effect of restoring eastern oyster reefs on average spat size varied with the restoration material used. One replicated, controlled study in the North Pacific Ocean found that restoring oyster reefs by placing lines of clam shells below Mean Lower Low Water (MLLW) led to similar growth of oysters on the shells than placing lines above MLLW. Four replicated, controlled studies in the North Pacific Ocean found that restoring oyster reefs by placing lines of clam shells below Mean Lower Low Water (MLLW) led to higher cover of clam shells by non-native species than placing lines above MLLW, but that for those placed below MLLW, moving them above MLLW halfway through the study led to lower cover than keeping then below, that cover was similar on lines placed on cobbly seabed or muddy seabed, and that cover of clam shells by non-native species was higher on lines placed near compared to far from the nearest adult oyster populations. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2248https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2248Wed, 23 Oct 2019 09:37:47 +0100Collected Evidence: Collected Evidence: Provide artificial shelters Five studies examined the effects of providing artificial shelters on subtidal benthic invertebrates. Three studies were in the Caribbean Sea (Mexico); one in Florida Bay and one in the Florida Keys (USA).   COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (2 STUDIES) Lobster abundance (2 studies): Two replicated, controlled, before-and-after studies in the Caribbean Sea found that abundance of lobsters either increased in plots with artificial shelters but not in plots without, or increased in all plots but more so in plots with artificial shelters than those without. Lobster condition (1 study): One replicated, controlled, before-and-after study in the Caribbean Sea found that lobsters in plots with artificial shelters were bigger than in plots without. BEHAVIOUR (3 STUDIES) Use (3 studies): Three replicated studies (two controlled) in Florida Bay, the Florida Keys, and the Caribbean Sea, found that artificial shelters were occupied by lobsters and molluscs, that occupancy by lobsters varied with artificial shelter designs, that lobsters occupied artificial shelters more than natural ones (crevices), and that lobsters occupying artificial shelters were larger, had greater nutritional condition, and had similar sex ratio and survival rate, compared to lobsters occupying natural shelters. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2257https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2257Wed, 23 Oct 2019 10:13:10 +0100Collected Evidence: Collected Evidence: Transplant/release captive-bred or hatchery-reared species - Transplant/release crustaceans Five studies examined the effects of transplanting or releasing hatchery-reared crustacean species on their wild populations. Four examined lobsters in the North Sea (Germany, Norway, UK), and one examined prawns in the Swan-Canning Estuary (Australia).   COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (5 STUDIES) Crustacean abundance (1 study): One study in the Swan-Canning Estuary  found that after releasing hatchery-reared prawn larvae into the wild, the abundance of egg-bearing female prawns increased. Crustacean reproductive success (3 studies): Two studies (one controlled) in the North Sea found that after their release, recaptured hatchery-reared female lobsters carried eggs, and the number, size and developmental stage of eggs were similar to that of wild females. One study in the Swan-Canning Estuary  found that after releasing hatchery-reared prawn larvae into the wild the overall population fecundity (egg production/area) increased. Crustacean survival (2 studies): Two studies in the North Sea found that 50–84% and 32–39% of hatchery-reared lobsters survived in the wild after release, up to eight and up to five years, respectively. Crustacean condition (4 studies): Two studies in the North Sea found that hatchery-reared lobsters grew in the wild after release. One controlled study in the North Sea found that after release into the wild, hatchery-reared female lobsters had similar growth rates as wild females. One study in the North Sea found that after releasing hatchery-reared lobsters, no recaptured lobsters displayed signs of “Black Spot” disease, and 95% had developed a crusher-claw. One study in the Swan-Canning Estuary  found that after releasing hatchery-reared prawn larvae into the wild, the size of egg-bearing female prawns increased. BEHAVIOUR (1 STUDY) Crustacean movement (1 study): One controlled study in the North Sea found that after release into the wild, hatchery-reared female lobsters had similar movement patterns as wild females. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2266https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2266Wed, 23 Oct 2019 12:11:24 +0100Collected Evidence: Collected Evidence: Establish temporary fishery closures Five studies examined the effects of establishing temporary fishery closures on marine fish populations. Two studies were in the North Atlantic Ocean (Canada, UK) and one study was in each of the North Sea (UK), the Philippine Sea (Palau) and the Mediterranean Sea (Spain).  COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Abundance (1 study): One before-and-after, site comparison study in the Atlantic Ocean found no increase in the biomass of the spawning stock of cod following a temporary fishery closure compared to fished areas over nine years. Survival (1 study): One before-and-after, site comparison study in the Atlantic Ocean found no change in the survival of cod following a temporary fishery closure compared to fished areas over nine years. Condition (1 study): One before-and-after, site comparison study in the Atlantic Ocean found no change in the length composition of cod following a temporary fishery closure, compared to fished areas over nine years. BEHAVIOUR (1 STUDY) Use (1 study): A study in the Northeast Atlantic Ocean reported that over five years tagged adult cod spent nearly a third of time inside a seasonally closed cod spawning area during implementation, and were thus given increased protection from any gears targeting bottom-dwelling fish during the spawning period. OTHER (4 STUDIES) Reduction of fishing effort (1 study): One replicated, controlled, before-and-after study in the North Sea found that fixed temporary closures had little effect on fishing effort for cod, but real-time area closures reduced the annual amount of cod caught (retained and discarded). Commercial catch abundance (3 studies): One of two replicated (one controlled, one before-and-after) studies in the Philippine Sea and Mediterranean Sea found that during a temporary closure of a grouper fishery, spear fisher catch numbers of other fish groups (herbivores) increased, indicating they were being targeted more compared to the open season. The other study found that in targeted fisheries over 10 years, catch rates of red mullet and total catch (fish and invertebrates combined), but not European hake, increased after temporary closures, compared to before. One before-and-after, site comparison study in the Atlantic Ocean found no change over nine years in cod catches following a temporary fishery closure compared to fished areas. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2664https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2664Wed, 18 Nov 2020 16:03:49 +0000Collected Evidence: Collected Evidence: Cease or prohibit spearfishing Five studies examined the effects of ceasing or prohibiting spearfishing in an area on marine fish populations. Two studies were in the Mediterranean Sea (France, Corsica). One study was in each of the Tasman Sea (Australia) and the Indian Ocean (South Africa). One study was a review of marine reserves around the world. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (4 STUDIES) Abundance (4 studies): Two of three site comparison studies in the Mediterranean Sea, the Tasman Sea and the Indian Ocean found that prohibiting spearfishing, and line fishing, in protected areas increased the abundances of European seabass and gilthead seabream (years unknown) and of coral reef fish species, compared to protected and unprotected fished areas, after two to seven years. The other study found that fish densities differed between spearfished and non-spearfished areas after 10–12 years, and was affected by depth and/or fish size. A review of reef marine reserves around the world reported that two non-spearfished reserves in the northwestern Atlantic had more snappers and grunts after two years in one, and higher densities of reef fish, including snappers and grunts after 20 years in the other, compared to nearby fished reefs. Condition (3 studies): Two site comparison studies in the Mediterranean Sea and the Indian Ocean found that prohibiting spearfishing (and linefishing) in marine protected areas resulted in larger European seabass and coral reef fish species, compared to protected and unprotected fished areas, after two to seven years. A review of global reef marine reserves reported that reef fish were larger in one reserve in the northwestern Atlantic that had banned spearfishing for 20 years, compared to nearby fished reefs. BEHAVIOUR (0 STUDIES) OTHER (1 STUDY)  Commercial catch abundance (1 study): One replicated, site-comparison study in the Mediterranean Sea found that prohibiting spearfishing in specific zones of a marine reserve resulted in higher commercial and recreational fishery catches of targeted common dentex compared to zones that allowed spearfishing and areas outside the reserve after one to three years.    Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2672https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2672Fri, 20 Nov 2020 09:32:23 +0000Collected Evidence: Collected Evidence: Deploy fishing gear at selected depths to avoid unwanted species Five studies examined the effect of deploying fishing gear at selected depths to avoid unwanted species on marine fish populations. Three studies were in the Atlantic Ocean (Florida, Brazil, Canary Islands), and one study was in each of the Pacific Ocean (Hawaii) and the Tasman Sea (Australia). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (5 STUDIES) Reduction of unwanted catch (5 studies): Four of five replicated studies (three controlled, one paired and controlled) in the Pacific Ocean, Atlantic Ocean and the Tasman Sea found that deploying fishing gear (longlines, handlines and traps) at selected depths, including above the seabed instead of on it, reduced the unwanted catches of five of 17 fish species, three of eight shark/ray species, non-commercially targeted fish species and Harrison’s dogfish, compared to depths usually fished. The other study found that different shark species were hooked at different depths in the water column during bottom-set longlining deployments.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2683https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2683Mon, 30 Nov 2020 16:26:13 +0000Collected Evidence: Collected Evidence: Use a different twine type in a trawl net Five studies examined the effects of using a different twine type in a trawl net on marine fish populations. Two studies were in each of the North Sea (UK) and the Western Baltic Sea (Denmark/Germany), and one study was in the Adriatic Sea (Italy). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (5 STUDIES) Improved size-selectivity of fishing gear (5 studies): Four of five replicated studies (four controlled) in the North Sea, Baltic Sea and Adriatic Sea found that using a different twine type (twine thickness and construction material) improved the size-selectivity of bottom fish, haddock, Atlantic cod, plaice and flounder, compared to thinner or other twine materials. One study found that selectivity of non-target haddock and plaice was similar for three different twine diameters. One of these studies also found that size-selectivity of fish was influenced by twine number and mesh orientation, while another found no effect of twine number and mesh orientation, but cod selectivity increased with a smaller codend circumference. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2710https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2710Tue, 29 Dec 2020 16:07:09 +0000Collected Evidence: Collected Evidence: Set a minimum landing size for commercially fished species Five studies examined the effects of setting a minimum landing size for commercially fished species on marine fish populations. One study was a global review and one study was in each of the Tasman Sea (Australia), the Baltic Sea (Northern Europe), the Ionian Sea (Greece) and the Northwest Atlantic Ocean (USA). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (2 STUDIES) Reproductive success (2 studies): One global review reported that one of five swordfish fisheries showed an increase in swordfish recruitment after the setting of recommended minimum landing sizes and catch limits, with recruitment in the other fisheries either highly variable or unable to be assessed. One replicated study in the Ionian Sea reported that, despite established minimum sizes, most fish landed in commercial catches were immature, and thus had never spawned. BEHAVIOUR (0 STUDIES) OTHER (3 STUDIES) Reduction of unwanted catch (3 studies): One of three before-and-after studies (one replicated) in the Atlantic Ocean, Tasman Sea and Baltic Sea found that following an increase in the set minimum landing size and mesh size of gill nets the catches of the youngest southern flounder were reduced. The other two found that increasing the minimum landing size did not reduce the catches of discarded dusky flathead and Atlantic cod3, and discarding of flathead increased in one of three cases. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2735https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2735Tue, 02 Feb 2021 14:28:08 +0000Collected Evidence: Collected Evidence: Prohibit or restrict hunting of marine and freshwater mammal species Five studies evaluated the effects of prohibiting hunting of marine mammal species. One study was in each of the Kattegat and Skagerrak seas (Denmark and Sweden), the North Atlantic Ocean, North Pacific Ocean and the Southern Hemisphere, the South Pacific Ocean (Australia), the North Atlantic Ocean (Greenland) and the Southern Ocean (Australia). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (5 STUDIES) Abundance (5 studies): Four of five studies (including three before-and-after studies) in the Kattegat and Skagerrak Seas, the South Pacific Ocean, the North Atlantic Ocean and the Southern Ocean found that after hunting was prohibited, the abundance of harbour seals and humpback whales increased over 7–30 years. The other study found that numbers of mature male sperm whales did not differ significantly before or 31 years after hunting was prohibited. One review in the North Atlantic Ocean, North Pacific Ocean and the Southern Hemisphere found significant increase rates for 10 of 12 baleen whale populations during 7–21 years after legislation to prohibit hunting was introduced. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2780https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2780Thu, 04 Feb 2021 16:09:52 +0000Collected Evidence: Collected Evidence: Use acoustically reflective fishing gear materials Five studies evaluated the effects on marine mammals of using acoustically reflective fishing gear materials. Two studies were in the Bay of Fundy (Canada) and one study was in each of the Fortune Channel (Canada), the North Sea (Denmark) and the South Atlantic Ocean (Argentina). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (2 STUDIES) Behaviour change (2 studies): One controlled study in the Fortune Channel found that harbour porpoises approached nets made from acoustically reflective material (barium sulfate) and conventional nets to similar distances and for similar durations, but porpoises used fewer echolocation clicks at barium sulfate nets. One controlled study in the Bay of Fundy found that harbour porpoise echolocation activity was similar at barium sulfate and conventional nets. OTHER (3 STUDIES) Reduction in entanglements/unwanted catch (3 studies): Two of three controlled studies (including two replicated studies) in the North Sea, the Bay of Fundy and the South Atlantic Ocean found that fishing nets made from acoustically reflective materials (iron-oxide or barium sulfate) had fewer entanglements of harbour porpoises than conventional fishing nets. The other study found that nets made from barium sulfate did not reduce the number of dolphin entanglements. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2807https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2807Thu, 04 Feb 2021 17:31:28 +0000Collected Evidence: Collected Evidence: Use acoustic devices on fishing vessels Five studies evaluated the effects on marine mammals of using acoustic devices on vessels. One study was in each of the Shannon Estuary (Ireland), the Rainbow Channel (Australia), Keppel Bay (Australia), the North Atlantic Ocean (Azores) and the Indian Ocean (Crozet Islands). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (4 STUDIES) Behaviour change (4 studies): One controlled study in the Shannon Estuary found that common bottlenose dolphins avoided a boat more frequently when acoustic devices of two types were deployed alongside it. One controlled study in the Indian Ocean found that killer whales were recorded further from a fishing vessel when an acoustic device was used during hauls, but distances decreased after the first exposure to the device. Two before-and-after studies in the Rainbow Channel and Keppel Bay found that an acoustic device deployed alongside a vessel reduced surfacing and echolocation rates and time spent foraging or socializing of Indo-Pacific humpback dolphins and Australian snubfin dolphins but there was no effect on 8–10 other types of behaviour (e.g. vocalizing, diving, travelling etc.). OTHER (1 STUDY) Human-wildlife conflict (1 study): One randomized, controlled study in the North Atlantic Ocean found that using acoustic devices of two types did not reduce predation of squid catches by Risso’s dolphins. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2815https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2815Fri, 05 Feb 2021 14:45:12 +0000Collected Evidence: Collected Evidence: Use catch and hook protection devices on fishing gear Five studies evaluated the effects on marine mammals of using catch and hook protection devices on fishing gear. Two studies were in the South Pacific Ocean (Chile, Australia and Fiji), two were in the Indian Ocean (Seychelles, Madagascar) and one was in the Southwest Atlantic Ocean. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (5 STUDIES) Reduction in entanglements/unwanted catch (1 study): One study in the South Pacific Ocean found that using cage or chain devices on fishing hooks resulted in fewer unwanted catches of toothed whales. Human-wildlife conflict (5 studies): Two of four studies (including three controlled and one before-and-after study) in the South Pacific Ocean, the Southwest Atlantic Ocean and the Indian Ocean found that net sleeves or cage and chain devices on fishing hooks reduced damage to fish catches by sperm whales, killer whales and toothed whales. The two other studies found that attaching ‘umbrella’ or ‘spider’ devices on fishing hooks did not reduce predation and/or damage to fish catches by sperm whales or toothed whales. One controlled study in the Indian Ocean found that attaching catch protection devices made from streamers to fishing lines reduced Indo-Pacific bottlenose and spinner dolphin predation on fish bait, but only during the first two trials. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2821https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2821Fri, 05 Feb 2021 15:18:24 +0000Collected Evidence: Collected Evidence: Sow grassland seeds from a local source Five studies examined the effects of sowing grassland seeds from a local source on grassland vegetation. Two studies were in Germany, two were in the USA and one was in Italy. VEGETATION COMMUNITY (2 STUDIES) Overall richness/diversity (1 study): One replicated, controlled study in Italy found that sowing grassland seeds from a local source increased plant species richness compared to sowing a commercial seed mix. Characteristic plant richness/diversity (1 study): One replicated, controlled study in Germany found that sowing grassland seeds from a local source, along with increasing the number of species in a seed mix, led to an increase in the species richness of target plants. VEGETATION ABUNDANCE (3 STUDIES) Overall abundance (2 studies): One of two replicated studies (including one site comparison and one controlled study) in the USA and Germany found that after sowing grassland seeds from a local source vegetation cover increased over time compared to areas sown with non-native seeds, but the density of individual plants declined. The other study found that vegetation cover did not differ to that in areas sown with commercial grass seed. Characteristic plant abundance (2 studies): One replicated, controlled study in Germany found that sowing grassland seeds from a local source, along with increasing the number of species in a seed mix, led to an increase in the cover of target plant species. One replicated, randomized, paired, controlled study in Germany found that sowing grassland seeds from a local source increased the abundance of one of four characteristic plant species that were sown. VEGETATION STRUCTURE (2 STUDIES) Height (2 studies): Two replicated studies (including one controlled and one site comparison study) in the USA and Italy found that sowing grassland seeds from a local source did not alter vegetation height compared to sowing non-native grass seeds or a commercial seed mix. OTHER (1 STUDY) Survival (1 study): One replicated, randomized, controlled experiment in the USA found that sowing Sandberg bluegrass seeds from a local source did not change the survival of sown plants compared to sowing non-local varieties. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3400https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3400Fri, 25 Jun 2021 14:08:23 +0100Collected Evidence: Collected Evidence: Increase number of species in seed mix Five studies examined the effects of increasing the number of species in a seed mix on grassland vegetation. Four studies were in the USA and one was in Germany. VEGETATION COMMUNITY (4 STUDIES) Overall richness/diversity (1 study): One replicated, site comparison study in the USA found that increasing the number of species in a seed mix did not change plant species richness. Characteristic plant richness/diversity (1 study): One replicated, controlled study in Germany found that increasing the number of species in a seed mix, along with sowing seeds from a local source, increased the species richness of target plants. Sown/planted species richness/diversity (2 studies): Two replicated, controlled studies in the USA (one of which was randomized) found that increasing the number species in a seed mix increased the species richness of sown plants. VEGETATION ABUNDANCE (3 STUDIES) Characteristic plant abundance (1 study): One replicated, controlled study in Germany found that increasing the number of species in a seed mix, along with sowing seeds from a local source, increased the cover of target plant species. Sown/planted species abundance (2 studies): One of two replicated, controlled studies (one of which was randomized) in the USA found that increasing the number of species in a seed mix increased the cover of sown plant species. The other study found that there was no change in the cover of sown species. VEGETATION STRUCTURE (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3406https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3406Fri, 25 Jun 2021 14:56:06 +0100Collected Evidence: Collected Evidence: Drill seed rather than seeding by hand Five studies examined the effects of drill seeding rather than sowing by hand on grassland vegetation. The studies were in the USA. VEGETATION COMMUNITY (3 STUDIES) Overall richness/diversity (3 studies): Two of three replicated, controlled studies (two of which were paired) in the USA found that sowing seeds with a seed drill did not alter plant species richness. The other study found mixed effects. VEGETATION ABUNDANCE (4 STUDIES) Sown/planted species abundance (3 studies): One of three replicated, controlled studies (two of which were randomized and one paired) in the USA found that sowing seeds with a seed drill increased the density of two sown grass species compared to sowing by hand. The two other studies found that in most cases sowing seeds with a seed drill led to no change or a reduction in the abundance of sown plants compared to hydroseeding or sowing by hand. Grass abundance (1 study): One replicated, paired, controlled study in the USA found that sowing grassland seeds with a seed drill increased the abundance of warm-season grass species compared to sowing by hand. VEGETATION STRUCTURE (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3410https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3410Fri, 25 Jun 2021 15:23:50 +0100Collected Evidence: Collected Evidence: Inoculate soil with mycorrhiza before seeding/planting Five studies examined the effects of inoculating soil with mycorrhiza before seeding/planting on grassland vegetation. Four studies were in the USA and one was in Germany. VEGETATION COMMUNITY (1 STUDY) Overall richness/diversity (1 study): One replicated, randomized, controlled study in Germany found that inoculating soil with mycorrhizal fungi and sowing seeds of grassland species did not alter plant species richness. VEGETATION ABUNDANCE (4 STUDIES) Overall abundance (2 studies): One replicated, randomized, paired, controlled study in the USA found that inoculating soil with mycorrhizal fungi before sowing seeds initially increased vegetation cover, but after three years, vegetation cover did not differ between areas that were and were not inoculated. One controlled study in the USA found that adding soil microbes and nutrients when planting grass plugs did not change the overall cover of herbaceous species. Characteristic plant abundance (2 studies): One replicated, randomized, controlled study in Germany found that adding mycorrhiza to the soil and sowing seeds of grassland species increased the abundance of target species that were considered a local conservation priority. One controlled study in the USA found that adding soil microbes and nutrients when planting grass plugs increased the cover of three of 38 native prairie species. Tree/shrub abundance (1 study): One controlled study in the USA found that adding soil microbes and nutrients when planting grass plugs did not change the cover of woody species. Native/non-target species abundance (1 study): One replicated, controlled study in the USA found that adding mycorrhizal fungi to soil before sowing seeds did not alter the biomass of three native grass and forb species. VEGETATION STRUCTURE (1 STUDY) Height (1 study): One replicated, controlled study in the USA found that adding mycorrhizal fungi to soil before sowing seeds increased the height of giant sacaton plants. Individual plant size (1 study): One replicated, controlled study in the USA found that adding mycorrhizal fungi to soil before sowing seeds did not increase the biomass of giant sacaton plants. OTHER (1 STUDY) Germination/Emergence (1 study): One replicated, controlled study in the USA found that adding mycorrhizal fungi to soil before sowing seeds did not increase the emergence of giant sacaton plants. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3429https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3429Mon, 28 Jun 2021 13:23:20 +0100Collected Evidence: Collected Evidence: Create long flexible habitats (>50 mm) on subtidal artificial structures Five studies examined the effects of creating long flexible habitats on subtidal artificial structures on the biodiversity of those structures. Three studies were in estuaries in southeast Australia and two were in a port in the Netherlands. COMMUNITY RESPONSE (2 STUDIES) Overall community composition (2 studies): Two replicated, controlled studies (including one randomized study) in Australia and the Netherlands reported that long flexible habitats created on subtidal artificial structures supported macroalgae and non-mobile invertebrate or fish species that were absent from on and around structure surfaces without flexible habitats. Invertebrate community composition (1 study): One replicated, controlled study in the Netherlands reported that creating long flexible habitats on subtidal artificial structures altered the non-mobile invertebrate community composition on structure surfaces. Fish richness/diversity (1 study): One replicated, randomized, controlled study in Australia found that creating long flexible habitats on subtidal artificial structures had mixed effects on the fish species richness around structures, depending on fish presence when flexible habitats were created. POPULATION RESPONSE (4 STUDIES) Overall abundance (1 study): One replicated, controlled study in the Netherlands reported that long flexible habitats created on subtidal artificial structures supported higher combined macroalgae and invertebrate (mostly mussels) biomass than structure surfaces without flexible habitats, and found that deeper flexible habitats supported higher biomass than shallower ones. Invertebrate abundance (3 studies): Two of three studies (including two replicated, two controlled and one randomized study) in Australia and the Netherlands found that creating long flexible habitats on subtidal artificial structures had mixed effects on the mobile and/or non-mobile invertebrate abundance on and around structure surfaces, depending on the species group and survey week, or the flexible habitat length and density. One study reported that creating flexible habitats decreased the mussel abundance on structure surfaces but that the flexible habitats themselves supported higher biomass (mostly mussels) than the structure surfaces. Fish abundance (2 studies): Two randomized, controlled studies (including one replicated study) in Australia found that creating long flexible habitats on subtidal artificial structures had mixed effects on the abundance of fishes or seahorses on and around structures, depending on the species and fish presence when flexible habitats were created, or the survey week. BEHAVIOUR (1 STUDY) Use (1 study): One replicated study in Australia reported that long flexible habitats created on subtidal artificial structures were used by seahorses. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3451https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3451Thu, 09 Sep 2021 12:22:16 +0100Collected Evidence: Collected Evidence: Create hole habitats (>50 mm) on intertidal artificial structures Five studies examined the effects of creating hole habitats on intertidal artificial structures on the biodiversity of those structures. Three studies were in estuaries in southeast Australia and the UK, one was on an open coastline in the Netherlands, and one was in a marina in northern Israel. COMMUNITY RESPONSE (3 STUDIES) Overall community composition (3 studies): One replicated, randomized, paired sites, controlled, before-and-after study in Israel found that creating hole habitats on an intertidal artificial structure, along with grooves, small ridges and environmentally-sensitive material, altered the combined macroalgae and invertebrate community composition on structure surfaces. The study, along with two other replicated, controlled studies in Australia and the UK, also reported that hole habitats, along with rock pools, or grooves, small protrusions and environmentally-sensitive material, supported macroalgae and/or non-mobile invertebrate species that were absent from structure surfaces without added habitat features. Overall richness/diversity (3 studies): Three replicated, controlled studies (including one randomized, paired sites, before-and-after study) in Australia, the UK and Israel found that creating hole habitats on intertidal artificial structures, along with rock pools, or grooves, small protrusions and environmentally-sensitive material, increased the combined macroalgae and invertebrate species diversity and/or richness on structure surfaces. POPULATION RESPONSE (2 STUDIES) Algal abundance (1 study): One replicated, paired sites, controlled study in the Netherlands reported that creating hole habitats on an intertidal artificial structure did not increase the macroalgal abundance on structure surfaces. Invertebrate abundance (2 studies): One of two replicated, controlled studies (including one paired sites study) in Australia and the Netherlands reported that creating hole habitats on an intertidal artificial structure did not increase the invertebrate abundance on structure surfaces. One study found that creating holes, along with rock pools, had mixed effects on the limpet abundance, depending on the shore level and site. BEHAVIOUR (1 STUDY) Use (1 study): One study in Australia reported that hole habitats created on an intertidal artificial structure, along with rock pools, were used by sea slugs, urchins and octopuses. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3467https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3467Thu, 16 Sep 2021 11:18:24 +0100Collected Evidence: Collected Evidence: Use prescribed fire to maintain or restore disturbance in forests Five studies evaluated the effects on butterflies and moths of using prescribed fire to maintain or restore disturbance in forests. Four studies were in the USA and one was in Australia. COMMUNITY RESPONSE (4 STUDIES) Richness/diversity (4 studies): Three of four studies (including one replicated study, one paired study, two controlled studies, two before-and-after studies, and one site comparison study) in the USA found that coniferous forest restored 1–2 years ago by burning (in combination with thinning) or burned once within the last 20 years, had a higher species richness of butterflies than unburned forest. The fourth study found that mixed forest and shrubland sites which had been burned the year before had similar butterfly species richness to unburned sites. POPULATION RESPONSE (3 STUDIES) Abundance (3 studies): Two studies (including one controlled, before-and-after study and one site comparison study) in the USA found that pine forest restored 1–2 years ago by burning (in combination with thinning) had a higher abundance of butterflies than unburned forest. One replicated, before-and-after study in Australia reported that in the spring after selective burning of eucalyptus forest there were fewer Eltham copper caterpillars than before. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3877https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3877Wed, 20 Jul 2022 18:19:12 +0100Collected Evidence: Collected Evidence: Remove, control or exclude native predators Five studies evaluated the effects on butterflies and moths of removing, controlling or excluding native predators. Two studies were in each of the UK and the USA and one was in Kenya. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (5 STUDIES) Survival (5 studies): Three of five replicated studies (including one randomized, paired, controlled study and three paired, controlled studies) in the UK, Kenya and the USA found that using mesh cages, net sleeves and sticky resin to exclude predators (including birds and mammals and spiders and ants) increased the survival of large copper caterpillars, Boisduval silkworm eggs and caterpillars and Appalachian brown eggs and juveniles. The other two studies found that using cages or water and chemicals to exclude vertebrate or terrestrial predators (mainly ants) did not increase the survival of monarch caterpillars. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3889https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3889Tue, 26 Jul 2022 18:30:11 +0100Collected Evidence: Collected Evidence: Restrict certain pesticides or other agricultural chemicals Five studies evaluated the effects on butterflies and moths of restricting the use of certain pesticides or other agricultural chemicals. Three studies were in the UK, and one was in each of Germany and Italy. COMMUNITY RESPONSE (3 STUDIES) Richness/diversity (3 studies): Two replicated, site comparison studies in the UK and Italy found that arable field margins and rice field banks which were not sprayed with the herbicide glyphosate had a greater species richness of butterflies than margins and banks sprayed once/year for 1–3 years. One replicated, randomized, controlled study in the UK found that grass strips which were not sprayed with the herbicide fluazifop-P-butyl had a similar species richness of butterflies to strips sprayed once. POPULATION RESPONSE (5 STUDIES) Abundance (5 studies): Three replicated, site comparison studies (including two randomized studies) in the UK and Italy found that arable field margins and rice field banks which were not sprayed with the herbicide glyphosate had a higher total abundance of butterflies, and of meadow brown and large copper specifically, than margins and banks sprayed once/year for 1–3 years. One controlled study in Germany found that white campion plants sprayed with water had a higher abundance of lychnis moth eggs and caterpillars after one night than plants sprayed with the insecticide Karate Zeon. One replicated, randomized, controlled study in the UK found that grass strips which were not sprayed with the herbicide fluazifop-P-butyl had a similar abundance of butterflies to strips sprayed once. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3896https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3896Tue, 09 Aug 2022 13:23:40 +0100
What Works 2021 cover

What Works in Conservation

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

More about What Works in Conservation

Download free PDF or purchase
The Conservation Evidence Journal

The Conservation Evidence Journal

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

Read the latest volume: Volume 21

Go to the CE Journal

Discover more on our blog

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

Who uses Conservation Evidence?

Meet some of the evidence champions

Endangered Landscape ProgrammeRed List Champion - Arc Kent Wildlife Trust The Rufford Foundation Save the Frogs - Ghana Mauritian Wildlife Supporting Conservation Leaders
Sustainability Dashboard National Biodiversity Network Frog Life The international journey of Conservation - Oryx Cool Farm Alliance UNEP AWFA Bat Conservation InternationalPeople trust for endangered species Vincet Wildlife Trust
For a full list of, and information about, our champions:
All Evidence Champions
About our champions, why and how to become one:
Become an Evidence Champion

This website uses Cookies

We use limited Cookies to run the site and to analyse our traffic (none for site vendors). By using this site, you will be providing your consent to our use of Cookies.

Accept & continue