Collected Evidence: Collected Evidence: Cease or prohibit all (mobile and static) fishing gears that catch bottom (demersal) species Three studies examined the effects of ceasing or prohibiting mobile and static fishing gears that catch bottom (demersal) species in an area on marine fish populations. One study was in each of the Greenland Sea (Iceland), the North Pacific Ocean (Canada) and the North Atlantic Ocean (USA/Canada). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (3 STUDIES) Abundance (3 studies): One of three replicated, controlled studies (one paired) in the Greenland Sea, North Pacific Ocean and the North Atlantic Ocean found that an area where fishing gears targeting bottom-dwelling species had been prohibited for 15 years had higher numbers of larger and older cod than openly fished areas. One study found that fish densities in areas closed to mobile and static bottom fish gears (trawls and longlines) for at least 11 years varied between fish species/groups, and also with depth and temperature. The other study found that prohibiting mobile and static bottom fish gears (trawls and hook and line) in protected areas for 2–7 years had no effect on fish densities compared to non-protected areas. Condition (2 studies): One of two replicated, controlled studies (one paired) in the Greenland Sea and the North Atlantic Ocean found that cod had better growth in areas closed for 5-15 years to mobile and static gears that targeted bottom-dwelling fish, compared to openly fished areas. The other study found that fish size varied between areas closed and open to bottom fish gears (trawls and longlines) and was also affected by depth and temperature. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F2654https%3A%2F%2Fconservationevidence.com%2Factions%2F2654Thu, 12 Nov 2020 14:42:52 +0000Collected Evidence: Collected Evidence: Cease or prohibit all commercial fishing Eight studies examined the effects of ceasing or prohibiting all commercial fishing in an area on marine fish populations. Two studies were in the Tasman Sea (Australia), and one was in each of the Indian Ocean (Australia), the Mediterranean Sea (Spain), the Greenland Sea (Iceland), the Gulf of Mexico (USA), the South China Sea (China) and the South Atlantic Ocean (South Africa). COMMUNITY RESPONSE (3 STUDIES) Community composition (3 studies): Two before-and-after studies (one site comparison) in the Tasman Sea and South China Sea found that the fish assemblage/species composition was different before and after prohibiting all commercial fishing, in an estuary after two years, and in the nearby wider region surrounding two marine reserves five years after their creation. One site comparison study in the South Atlantic Ocean found no change in species composition between a reserve closed to all commercial fishing for 40 years and unprotected fished areas. Richness/diversity (2 studies): One site comparison study in the South Atlantic Ocean found no difference in overall fish diversity between a protected area closed to all commercial fishing for 40 years compared to unprotected fished areas. One before-and-after study in the South China Sea found that fish species richness decreased in the wider region five years after all commercial fishing was banned in two marine reserves. POPULATION RESPONSE (7 STUDIES) Abundance (7 studies): Two of four site comparison studies (one replicated, one before-and-after) in the Mediterranean Sea, Indian Ocean, south Atlantic Ocean and the Gulf of Mexico found that in protected areas prohibiting all commercial fishing for five years and 40 years there were higher abundances of three of 12 commercially targeted and non-targeted fish species/groups and one of four commercially targeted fish species, compared to unprotected fished areas. One study found mixed effects on fish densities 30–40 years after banning all commercial fishing, varying with level of commercial exploitation, and higher abundances of five of five commercially exploited species. The other study found there was no increase in white seabream and gilthead bream biomass 2–13 years after closure compared to an unprotected fished area, but it was lower than a no-take area protected for over nine years. One before-and-after, site comparison study in the Tasman Sea found that most fish species in an estuary in a marine reserve had a lower abundance two years after it was closed to all commercial fishing than before, as did one of two reference sites in unprotected adjacent estuaries. One before-and-after study in the South China Sea found that in the five years after the creation of two marine reserves with limits on commercial fishing activity, overall fish density in the nearby wider region increased. One replicated, site comparison study in the Tasman Sea found that in areas of a marine reserve closed to commercial trapping, fish abundance varied over 10 years and was higher for some groups than others compared to reserve sites open to trapping. Condition (1 study): One replicated, site comparison study in the Indian Ocean found that in marine reserve areas banning all commercial fishing for five years, overall fish size was bigger compared to fished areas. BEHAVIOUR (1 STUDY) Use (1 study): One replicated, controlled study in the Greenland Sea found that areas closed to commercial fishing (trawling) had higher recaptures of tagged smaller immature cod than adult cod over time compared to trawled areas, indicating they were more likely to have an increased protection from fishing. Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F2667https%3A%2F%2Fconservationevidence.com%2Factions%2F2667Thu, 19 Nov 2020 11:03:46 +0000Collected Evidence: Collected Evidence: Cease or prohibit shellfish dredging One study examined the effects of ceasing or prohibiting shellfish dredging on marine fish populations. The study was in the North Sea (Denmark). COMMUNITY RESPONSE (1 STUDY) Richness/diversity (1 study): One before-and-after, site comparison study in the North Sea reported that 10 years after mussel dredging ceased in an area closed to all towed fishing gears there was no change in species richness of bottom-dwelling fish compared to before and to open areas. POPULATION RESPONSE (1 STUDY) Abundance (1 study): One before-and-after, site comparison study in the North Sea, reported that ceasing mussel dredging in an area closed to all towed gears had no effect on the abundance of bottom-dwelling fish after 10 years, and compared to open areas. BEHAVIOUR (0 STUDIESCollected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F2668https%3A%2F%2Fconservationevidence.com%2Factions%2F2668Thu, 19 Nov 2020 15:42:05 +0000Collected Evidence: Collected Evidence: Cease or prohibit mobile midwater (pelagic) fishing gears One study examined the effects of ceasing or prohibiting fishing with towed (mobile) midwater fishing gears on marine fish populations. The study was in the Norwegian Sea (Norway). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Condition (1 study): One replicated, before-and-after study in the Norwegian Sea found that in the five years after drift netting was prohibited in an area, the weights of young salmon returning to rivers were higher than before, and weights of older salmon were similar or lower. Abundance (1 study): One replicated, before-and-after study in the Norwegian Sea found that in the five years after the use of drift nets was prohibited, there were more young salmon returning to rivers than before, and similar numbers of older multi-returning salmon. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F2669https%3A%2F%2Fconservationevidence.com%2Factions%2F2669Thu, 19 Nov 2020 16:06:33 +0000Collected Evidence: Collected Evidence: Cease or prohibit all non-towed (static) fishing gear One study examined the effects of ceasing or prohibiting all non-towed (static) fishing gears on marine fish populations. The study was in the Coral Sea (Australia).   COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Abundance (1 study): One replicated, site comparison study in the Coral Sea found that in areas closed to non-towed fishing gears overall shark abundance was higher when sampled with longlines but not gillnets compared to areas where commercial gillnets were permitted. Condition (1 study): One replicated, site comparison study in the Coral Sea found that in areas closed to non-towed fishing gears shark length was greater for two of five species/groups, similar for two and dependent on sampling gear for one species, compared to areas where commercial gillnets were permitted. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F2670https%3A%2F%2Fconservationevidence.com%2Factions%2F2670Thu, 19 Nov 2020 16:10:49 +0000Collected Evidence: Collected Evidence: Cease or prohibit line fishing One study examined the effects of ceasing or prohibiting line fishing in an area on marine fish populations. The study was in the Indian Ocean (South Africa). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY)  Abundance (1 study): One site comparison study in the Indian Ocean found that prohibiting offshore line fishing and all other boat-based fishing in a zone of a marine protected area resulted in higher abundances of four of four fish species over-exploited by line fishing, compared to two zones where boat-based line and spear fishing was permitted. Condition (1 study): One site comparison study in the Indian Ocean found that in a zone of a marine protected area closed to offshore line fishing and all other boat-based fishing for two to seven years, four of four fish species over-exploited by line fishing were larger, compared to two zones where boat-based line and spear fishing was permitted. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F2671https%3A%2F%2Fconservationevidence.com%2Factions%2F2671Thu, 19 Nov 2020 16:41:12 +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%2Fconservationevidence.com%2Factions%2F2672https%3A%2F%2Fconservationevidence.com%2Factions%2F2672Fri, 20 Nov 2020 09:32:23 +0000Collected Evidence: Collected Evidence: Cease or prohibit mobile fishing gears that catch bottom (demersal) species and are dragged across the seafloor Ten studies examined the effects of ceasing or prohibiting mobile fishing gears that catch bottom (demersal) species and are dragged across the seafloor on marine fish populations. Two studies were in each of the North Atlantic Ocean (Canada, Portugal), the Indian Ocean (Tasmania, Kenya) and the Mediterranean Sea. One study was in each of the North Sea (Denmark), the Arafura Sea (Australia), the Coral Sea (Australia) and the Gulf of Mexico (USA). COMMUNITY RESPONSE (3 STUDIES)  Richness/diversity (3 studies): Two of three site comparison studies (one replicated and randomized, and one before-and-after) in the North Sea, Indian Ocean and Gulf of Mexico found that the number of fish species, the fish assemblage and overall species richness and diversity (fish and invertebrates combined) varied between areas with different exposures to bottom trawling, and was also dependent on bottom depth and habitat type. The other study reported no effect of closing an area to all towed bottom fishing gears on the species richness of bottom-dwelling fish after 10 years and compared to areas open to trawling.  POPULATION RESPONSE (8 STUDIES) Abundance (5 studies): Two of three replicated studies (one controlled and before-and-after, and two site comparison) and one of two before-and-after studies (one site comparison) in the North Sea, Arafura Sea, North Atlantic Ocean and the Mediterranean Sea found that ceasing or prohibiting fishing with towed bottom gears resulted in higher total fish biomass after 15 years, higher biomass of adult red mullet after 14 years and increased abundances of long-snouted, but not short-snouted, seahorses after one year, compared to openly fished areas. The other two studies found that a ban on towed bottom fishing gears for five and 10 years had no effect on the abundance of bottom-dwelling fish species after closure compared to before, or the abundance and biomass of fish and invertebrate species (combined) compared to areas open to towed gears/trawling. Reproductive success (2 studies): One of two before-and-after studies (one site comparison) in the North Atlantic Ocean and Mediterranean Sea found that after the closure of an area to all bottom-towed fishing gears for 14 years, recruitment of young red mullet had increased. The other study found that an area closed to bottom trawling did not have higher recruitment of young haddock seven years after closure and compared to a trawled area. Survival (1 study): One before-and-after, site comparison study in the North Atlantic Ocean found that closing an area to bottom trawling did not increase the survival of young haddock seven years after closure, and compared to a trawled area. Condition (5 studies): One of four replicated studies (two site comparison and one randomized, site comparison) and one before-and-after study in the Arafura Sea, Mediterranean Sea, Gulf of Mexico and the Indian Ocean found that areas prohibiting bottom towed fishing gears had larger sizes of adult red mullet 14 years after closure than before. Two studies found that the effect on fish size of closing areas to towed bottom gears for 3–6 years or areas with no bottom fishing activity varied between individual fish groups and with habitat type, compared to fished areas. The other two found that areas closed to bottom trawling for five years and 15 years had no effect on the overall size of fish and invertebrate species combined or average fish weight, compared to trawled areas. BEHAVIOUR (0 STUDIES) OTHER (2 STUDIES) Reduce unwanted catch (1 study): One randomized, replicated, site comparison study in the Coral Sea found no reduction in the biomass of non-commercial unwanted catch (fish and invertebrate discard) or in the number of ‘common’ and ‘rare’ discard species in areas closed to trawling for seven years compared to trawled areas. Catch abundance (1 study): One replicated, before-and-after study in the Indian Ocean found that areas prohibiting beach and all other seine nets for 3–6 years found overall fish catch rates were higher, and catch rates of individual fish groups were variable, compared to unrestricted areas. Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F2673https%3A%2F%2Fconservationevidence.com%2Factions%2F2673Fri, 20 Nov 2020 12:12:24 +0000Collected Evidence: Collected Evidence: Control human activity in a marine protected area with a zonation system of restrictions Eight studies examined the effects of controlling human activity in a marine protected area with a zonation system of restrictions on marine fish populations. Three studies were in the Indian Ocean (South Africa), two were in the Coral Sea (Australia), and one was in each of the Southern Atlantic Ocean (South Africa), the Ligurian Sea (Italy) and the Philippine Sea (Philippines). COMMUNITY RESPONSE (1 STUDY)  Richness/diversity (1 study): One site comparison study in the Philippine Sea found a higher number of fish species in the no-fishing/no access zone of a multi-zoned marine protected area compared to two partially fished zones and unprotected fished areas 10 to 15 years after implementation.  POPULATION RESPONSE (4 STUDIES) Condition (4 studies): Two of four site comparison studies in the southern Atlantic Ocean, Ligurian Sea, Indian Ocean and the Coral Sea found that controlling human activity in marine protected areas with a zonation system of restrictions resulted in larger average lengths of steentjies and three seabream species three years after implementation compared to unprotected fished areas, and lengths were largest within a no-take zone than a partially fished zone. Two other studies found larger sizes of four of four coral reef fish in a zone where nearly all fishing is prohibited compared to an adjacent zone with fewer fishing restrictions two to seven years after protection, and of two of six fish feeding groups in no-entry zones compared to both no-take and fished zones protected between 10 and 20 years. Abundance (6 studies): Two of four site comparison studies (one replicated) in the Ligurian Sea, Philippine Sea and the Coral Sea found that controlling human activity in protected areas with a zonation system of restrictions resulted in a greater biomass and/or abundance of fish species after 3–15 years compared to unprotected areas outside, and between the zones fish abundance varied with the level of restriction and between individual fish groups and sizes. The other two studies found higher density, biomass, and abundance of fish in non-fished zones (no-entry and no-take) compared to fished zones inside areas protected for 10 to 27 years depending on region, but the effect varied between fish feeding groups, zone protection level and reef region. One site comparison study in the Indian Ocean found higher abundances of four of four reef fish species in a zone where nearly all fishing is prohibited, compared to an adjacent zone with fewer fishing restrictions. One site comparison study in the Southern Atlantic Ocean found that steentjies in a protected zone closed to fishing but open to other recreational activities had a different age and sex structure to a fished multipurpose zone, and both were different to a distant unprotected fished site with low steentjie exploitation. BEHAVIOUR (2 STUDIES) Use (2 studies): Two site comparison studies in the Indian Ocean found that in marine protected areas with zonation systems of activity controls, most of the individuals of the reef fish species tagged and released inside the protected areas were recaptured again at almost the same locations over the following nine or four years, and mainly in the zones where all or nearly all fishing was prohibited for up to 20 years, indicating increased protection from fishing. Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F2674https%3A%2F%2Fconservationevidence.com%2Factions%2F2674Fri, 20 Nov 2020 16:38:07 +0000Collected Evidence: Collected Evidence: Cease or prohibit customary fishing (indigenous fishing for cultural and community needs) One study examined the effects of ceasing or prohibiting customary fishing in an area, on marine fish populations. The study was in the Bismark Sea (Papua New Guinea). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Abundance (1 study): One site comparison study in the Bismark Sea found a higher abundance of only one of seven fish species in an area closed to customary fishing for eight years, compared to an area open to customary fishing. BEHAVIOUR (1 STUDY) Behaviour change (1 study): One site comparison study in the Bismark Sea found that in an area closed to customary fishing for eight years, six of seven fish species had a lower flight response distance compared to an area open to customary fishing, making them more vulnerable to capture with spear guns. Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F2675https%3A%2F%2Fconservationevidence.com%2Factions%2F2675Fri, 27 Nov 2020 15:46:26 +0000Collected Evidence: Collected Evidence: Allow only small-scale, traditional (artisanal) fishing One study examined the effects of allowing only small-scale traditional (artisanal) fishing in an area on marine fish populations. The study was in the Adriatic Sea (Italy). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (1 STUDY) Commercial catch abundance (1 study): One site comparison study in the Adriatic Sea found that a marine protected area zone allowing only artisanal fishing activity for three years had higher overall commercial catch rates of five of seven species compared to unprotected areas openly fished. Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F2678https%3A%2F%2Fconservationevidence.com%2Factions%2F2678Fri, 27 Nov 2020 16:09:39 +0000Collected Evidence: Collected Evidence: Allow periodic fishing only One study examined the effects of allowing fishing only periodically in an area on marine fish populations. The study was in the Coral Sea (Vanuatu). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Abundance (1 study): One replicated, paired, site comparison study in the Coral Sea found that protected areas fished only for short periods over an 18 month to six-year period, had greater biomass than openly fished areas and similar fish biomass as areas permanently closed to fishing for six years. BEHAVIOUR (0 STUDIES) OTHER (1 STUDY) Catch abundance (1 study): One replicated, paired, site comparison study in the Coral Sea found that protected areas only fished for short periods over an 18 month to six year period, had higher fish catch rates than openly fished areas. Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F2679https%3A%2F%2Fconservationevidence.com%2Factions%2F2679Fri, 27 Nov 2020 16:20:22 +0000Collected Evidence: Collected Evidence: Cease or prohibit all fishing activity in a marine protected area with limited exceptions Four studies examined the effects of ceasing or prohibiting all fishing activity in a marine protected area with limited exceptions on marine fish populations. One study was in each of the Pacific Ocean (USA), the Caribbean Sea (US Virgin Islands), the Great Barrier Reef (Australia) and the Skagerrak (Norway). COMMUNITY RESPONSE (1 STUDY) Richness/diversity (1 study): One site comparison study in the Caribbean Sea found that in marine protected areas closed to all fishing with limited exceptions for up to seven years, there was lower total fish species richness compared to unprotected areas. POPULATION RESPONSE (3 STUDIES) Abundance (2 studies): One replicated, site comparison study in the Pacific Ocean found that abundance of copper rockfish, quillback rockfish, china rockfish and lingcod was similar between non-voluntary and voluntary ‘no-take’ reserve sites where all fishing with limited exceptions had been prohibited for one to eight years, and sites open to fishing. One site comparison study in the Caribbean Sea found that restricting all fishing activity except for bait fishing in marine protected areas for seven years resulted in similar total fish biomass and lower total fish density, compared to unprotected areas. Survival (1 study): One replicated, controlled, before-and-after study in the Skagerrak found that cod survival increased inside a marine protected area in the eight years after almost all fishing was prohibited, compared to outside areas fished with a wider range of gear types. BEHAVIOUR (1 STUDY) Use (1 study): One replicated study in the Great Barrier Reef found that immature pigeye sharks and adult spottail sharks were detected frequently and over long time periods inside marine protected areas five years after prohibiting almost all fishing except restricted line fishing and bait netting, thus reducing the overall likelihood of fishing mortality. Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F2681https%3A%2F%2Fconservationevidence.com%2Factions%2F2681Fri, 27 Nov 2020 16:53:17 +0000Collected 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%2Fconservationevidence.com%2Factions%2F2682https%3A%2F%2Fconservationevidence.com%2Factions%2F2682Sat, 28 Nov 2020 14:35:06 +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%2Fconservationevidence.com%2Factions%2F2683https%3A%2F%2Fconservationevidence.com%2Factions%2F2683Mon, 30 Nov 2020 16:26:13 +0000Collected Evidence: Collected Evidence: Deploy fishing gear at selected times (day/night) to avoid unwanted species Two studies examined the effect of deploying fishing gear at selected times on marine fish populations. Both studies were in the South Pacific Ocean (Lake Wooloweyah, Australia).  COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (2 STUDIES)   Reduction of unwanted catch (2 studies): One of two replicated, controlled studies in the South Pacific Ocean found that trawling for prawns during the day reduced the overall catch of unwanted fish by number, but not weight, compared to usual night trawling, and the effect differed by species. The other study found that powered handlining in the day avoided catches of Harrison’s dogfish at shallower, but not deeper seamounts, compared to the night.    Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F2684https%3A%2F%2Fconservationevidence.com%2Factions%2F2684Mon, 30 Nov 2020 16:40:44 +0000Collected Evidence: Collected Evidence: Change the towing speed of a trawl net One study examined the effect of changing the towing speed of a trawl net on catch of marine fish. The study was in the North Sea (Norway).  COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (1 STUDY) Improved size-selectivity of fishing gear (1 study): One replicated, paired study in the North Sea found that changing the towing speed of a bottom trawl net did not increase the size selectivity of small cod and haddock. Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F2687https%3A%2F%2Fconservationevidence.com%2Factions%2F2687Wed, 02 Dec 2020 10:42:04 +0000Collected Evidence: Collected Evidence: Attach an electropositive deterrent to fishing gear Nine studies examined the effect of attaching an electropositive deterrent to fishing gear on marine fish populations. Three studies were in the Atlantic Ocean (USA, Canada, Bahamas). One study was in each of the Gulf of Alaska (USA), the South Pacific Ocean (Australia) and the Tasman Sea (Australia). One study was a global systematic review and two studies were in laboratory facilities (USA).  COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (4 STUDIES) Behaviour change (4 studies): Three of four replicated studies (one paired and controlled, one randomized and controlled, one randomized, and one controlled) in the Atlantic Ocean, Tasman Sea, and in laboratory conditions, found that the presence of potentially deterrent materials attached near the bait reduced the frequency of feeding attempts and bait consumption of spiny dogfish, great hammerhead and draughtboard sharks compared to the absence of deterrent materials. The other study found that a potentially deterrent material did not reduce bait consumption by bonnethead and young lemon sharks compared to non-deterrents. One of the studies also found that the bait consumption behaviour of commercially valuable Pacific halibut was unaffected by deterrent materials. OTHER (5 STUDIES) Reduction of unwanted catch (5 studies): Two of four replicated, controlled studies (one randomized) in the Gulf of Alaska, the Pacific Ocean and the Atlantic Ocean found that fishing gear (longlines and traps) fitted with electropositive deterrent materials caught fewer unwanted spiny dogfish, longnose skate, sharks and rays, and fewer undersized halibut, compared to standard fishing gear or gears with non-deterrent materials. The other two studies, and a global systematic review found that electropositive deterrents on fishing gear resulted in similar catches of unwanted spiny dogfish, sharks (total catch), blue shark and sharks and rays (total catch), compared to gear with no deterrents. Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F2696https%3A%2F%2Fconservationevidence.com%2Factions%2F2696Thu, 03 Dec 2020 12:05:21 +0000Collected Evidence: Collected Evidence: Change the size of the main body of a trawl net One study examined the effects of changing the size of the main body of a trawl net to reduce unwanted catch on marine fish populations. The study was in the North Sea (Norway). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (1 STUDY) Improved size-selectivity of fishing gear (1 study): One replicated study in the North Sea found that reducing the size of the main body of a trawl net did not improve the size-selection of cod and haddock. Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F2705https%3A%2F%2Fconservationevidence.com%2Factions%2F2705Thu, 17 Dec 2020 12:05:11 +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%2Fconservationevidence.com%2Factions%2F2706https%3A%2F%2Fconservationevidence.com%2Factions%2F2706Thu, 17 Dec 2020 14:51:11 +0000Collected Evidence: Collected Evidence: Deploy patrol boats We found no studies that evaluated the effects of deploying patrol boats on marine fish populations.  ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this intervention during our systematic journal and report searches. Therefore, we have no evidence to indicate whether or not the intervention has any desirable or harmful effects. Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F2738https%3A%2F%2Fconservationevidence.com%2Factions%2F2738Tue, 02 Feb 2021 15:08:05 +0000Collected Evidence: Collected Evidence: Eliminate flags of convenience We found no studies that evaluated the effects of eliminating flags of convenience on marine fish populations.  ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this intervention during our systematic journal and report searches. Therefore, we have no evidence to indicate whether or not the intervention has any desirable or harmful effects. Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F2769https%3A%2F%2Fconservationevidence.com%2Factions%2F2769Wed, 03 Feb 2021 10:27:16 +0000Collected Evidence: Collected Evidence: Eliminate fisheries subsidies that encourage overfishing We found no studies that evaluated the effects of eliminating fisheries subsidies that encourage overfishing on marine fish populations.   ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this intervention during our systematic journal and report searches. Therefore, we have no evidence to indicate whether or not the intervention has any desirable or harmful effects. Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F3820https%3A%2F%2Fconservationevidence.com%2Factions%2F3820Fri, 27 May 2022 08:47:44 +0100Collected Evidence: Collected Evidence: Employ adaptive management methods to achieve long-term goals We found no studies that evaluated the effects of employing adaptive management methods to achieve long-term goals on marine fish populations.   ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this intervention during our systematic journal and report searches. Therefore, we have no evidence to indicate whether or not the intervention has any desirable or harmful effects. Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F3827https%3A%2F%2Fconservationevidence.com%2Factions%2F3827Fri, 27 May 2022 09:41:07 +0100Collected Evidence: Collected Evidence: Enforce gear and vessel restrictions (e.g. cap engine power, ban gears) We found no studies that evaluated the effects of enforcing gear and vessel restrictions (e.g. cap engine power, ban gears) on marine fish populations.   ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this intervention during our systematic journal and report searches. Therefore, we have no evidence to indicate whether or not the intervention has any desirable or harmful effects. Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F3830https%3A%2F%2Fconservationevidence.com%2Factions%2F3830Mon, 30 May 2022 08:47:04 +0100
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What Works in Conservation

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

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