Collected Evidence: Collected Evidence: Set unwanted catch quotas We found no studies that evaluated the effects of setting unwanted catch quotas on subtidal benthic invertebrate populations.   ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this intervention during our systematic journal and report searches. Therefore, we have no evidence to indicate whether or not the intervention has any desirable or harmful effects.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2116https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2116Tue, 22 Oct 2019 09:47:18 +0100Collected Evidence: Collected Evidence: Use hook and line fishing instead of other fishing methods We found no studies that evaluated the effects of using hook and lime fishing instead of other fishing methods on subtidal benthic invertebrate populations.   ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this intervention during our systematic journal and report searches. Therefore, we have no evidence to indicate whether or not the intervention has any desirable or harmful effects.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2117https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2117Tue, 22 Oct 2019 09:47:59 +0100Collected Evidence: Collected Evidence: Use a midwater/semi-pelagic trawl instead of bottom/demersal trawl One study examined the effects of using a semi-pelagic trawl instead of a demersal trawl on subtidal benthic invertebrates. The study was in the Indian Ocean (Australia).   COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Overall abundance (1 study): One replicated, controlled, study in the Indian Ocean found that fishing with a semi-pelagic trawl did not reduce the abundance of large sessile invertebrates, which was similar to non-trawled plots, but a demersal trawl did. OTHER (1 STUDY) Commercial catch abundance (1 study): One replicated, controlled, study in the Indian Ocean found that fishing with a semi-pelagic trawl reduced the abundance of retained commercially targeted fish compared to fishing with a demersal trawl. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2118https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2118Tue, 22 Oct 2019 09:49:40 +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: Use lower water pressure during hydraulic dredging We found no studies that evaluated the effects of using lower water pressure during hydraulic dredging on subtidal benthic invertebrate populations.   ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this intervention during our systematic journal and report searches. Therefore, we have no evidence to indicate whether or not the intervention has any desirable or harmful effects.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2120https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2120Tue, 22 Oct 2019 10:02:49 +0100Collected Evidence: Collected Evidence: Use alternative means of getting mussel seeds rather than dredging from natural mussel beds We found no studies that evaluated the effects of using alternative means of getting mussel seeds rather than dredging from natural mussel beds on subtidal benthic invertebrate populations.   ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this intervention during our systematic journal and report searches. Therefore, we have no evidence to indicate whether or not the intervention has any desirable or harmful effects.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2122https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2122Tue, 22 Oct 2019 10:14:55 +0100Collected Evidence: Collected Evidence: Use an otter trawl instead of a dredge One study examined the effects of using an otter trawl instead of a dredge on subtidal benthic invertebrates. The study was 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 an otter trawl caught a different species composition of unwanted invertebrate and fish species (combined) compared to two scallop dredges. POPULATION RESPONSE (1 STUDY) Overall abundance (1 study): One replicated, controlled, study in the Irish Sea found no difference in total invertebrate abundance and biomass living in or on the sediment of the trawl tracks following fishing with either an otter trawl or two scallop dredges. Unwanted catch overall abundance (1 study): One replicated, controlled, study in the Irish Sea found that an otter trawl caught fewer unwanted invertebrates and fish (combined) compared to two scallop dredges. OTHER (1 STUDY) Commercial catch abundance (1 study): One replicated, controlled, study in the Irish Sea found that an otter trawl caught similar number of commercially targeted queen scallops compared to two scallop dredges. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2123https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2123Tue, 22 Oct 2019 10:16:36 +0100Collected Evidence: Collected Evidence: Use more than one net on otter trawls We found no studies that evaluated the effects of using more than one net on otter trawls on subtidal benthic invertebrate populations.   ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this intervention during our systematic journal and report searches. Therefore, we have no evidence to indicate whether or not the intervention has any desirable or harmful effects.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2124https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2124Tue, 22 Oct 2019 10:17:39 +0100Collected Evidence: Collected Evidence: Use an otter trawl instead of a beam trawl One study examined the effects of using an otter trawl instead of a beam trawl on subtidal benthic invertebrates. The study was in the North Sea (Germany and Netherlands).   COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Overall abundance (1 study): One replicated, paired, controlled study in the North Sea found that otter trawls caused similar mortality of invertebrates in the trawl tracks compared to beam trawls in sandy areas but lower mortality in silty areas. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2125https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2125Tue, 22 Oct 2019 10:19:09 +0100Collected Evidence: Collected Evidence: Use a pulse trawl instead of a beam trawl One study examined the effects of using a pulse trawl instead of a beam trawl on subtidal benthic invertebrates. The study was in the North Sea (Netherlands).   COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Unwanted catch abundance (1 study): One replicated, controlled, study in the North Sea found that pulse trawls caught less unwanted invertebrate catch compared to traditional beam trawls, but the effects varied with species. OTHER (1 STUDY) Commercial catch abundance (1 study): One replicated, controlled, study in the North Sea found that pulse trawls reduced the volume of commercial catch by 19% compared to beam trawls. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2126https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2126Tue, 22 Oct 2019 10:22:02 +0100Collected Evidence: Collected Evidence: Use a smaller beam trawl One study examined the effects of using a smaller beam trawl on subtidal benthic invertebrates. The study was in the North Sea (Germany and Netherlands).   COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Overall abundance (1 study): One replicated, paired, controlled study in the North Sea found that a smaller beam trawl caused similar mortality of invertebrates in the trawl tracks compared to a larger beam trawl. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2127https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2127Tue, 22 Oct 2019 10:23:07 +0100Collected Evidence: Collected Evidence: Modify trawl doors to reduce sediment penetration We found no studies that evaluated the effects of modifying trawl doors to reduce sediment penetration on subtidal benthic invertebrate populations.   ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this intervention during our systematic journal and report searches. Therefore, we have no evidence to indicate whether or not the intervention has any desirable or harmful effects.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2128https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2128Tue, 22 Oct 2019 10:24:53 +0100Collected Evidence: Collected Evidence: Outfit trawls with a raised footrope We found no studies that evaluated the effects of outfitting trawls with a raised footrope on subtidal benthic invertebrate populations.   ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this intervention during our systematic journal and report searches. Therefore, we have no evidence to indicate whether or not the intervention has any desirable or harmful effects.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2129https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2129Tue, 22 Oct 2019 10:25:27 +0100Collected Evidence: Collected Evidence: Limit the maximum weight and/or size of bobbins on the footrope We found no studies that evaluated the effects of limiting the maximum weight and/or size of bobbins on the footrope on subtidal benthic invertebrate populations.   ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this intervention during our systematic journal and report searches. Therefore, we have no evidence to indicate whether or not the intervention has any desirable or harmful effects.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2130https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2130Tue, 22 Oct 2019 10:26:05 +0100Collected Evidence: Collected Evidence: Use a larger codend mesh size on trawl nets One study examined the effects of using a larger codend mesh size on trawl nets on unwanted catch of subtidal benthic invertebrate populations. The study was in the Gulf of Mexico (Mexico).   COMMUNITY RESPONSE (1 STUDY) Unwanted catch species richness/diversity (1 study): One replicated, paired, controlled study in the Gulf of Mexico found that trawl nets fitted with a larger mesh codend caught fewer combined species of non-commercial unwanted invertebrates and fish compared to a traditional codend. POPULATION RESPONSE (1 STUDY) Unwanted catch abundance (1 study): One replicated, paired, controlled study in the Gulf of Mexico found that trawl nets fitted with a larger mesh codend caught lower combined biomass and abundance of non-commercial unwanted invertebrates and fish compared to a traditional codend. OTHER (1 STUDY) Commercial catch abundance (1 study): One replicated, paired, controlled study in the Gulf of Mexico found that trawl nets fitted with a larger mesh codend caught less biomass and abundance of commercially targeted shrimps compared to a traditional codend, but that the biomass ratios of commercially targeted to discard species was similar for both. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2135https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2135Tue, 22 Oct 2019 10:53:57 +0100Collected Evidence: Collected Evidence: Use a square mesh instead of a diamond mesh codend on trawl nets One study examined the effects of using a square mesh instead of a diamond mesh codend on trawl nets on unwanted catch of subtidal benthic invertebrate populations. The study was in the English Channel (UK).   COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Unwanted catch abundance (1 study): One replicated, paired, controlled study in the English Channel found that a trawl net with a square mesh codend caught less non-commercial unwanted invertebrates in one of two areas, and similar amounts in the other area, compared to a standard diamond mesh codend. OTHER (1 STUDY) Commercial catch abundance (1 study): One replicated, paired, controlled study in the English Channel found that a trawl net with a square mesh codend caught similar amounts of commercially targeted fish species in two areas, and that in one of two areas it caught more commercially important shellfish, compared to a standard diamond mesh codend. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2136https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2136Tue, 22 Oct 2019 10:56:11 +0100Collected Evidence: Collected Evidence: Modify the design/attachments of a shrimp/prawn W-trawl net One study examined the effects of modifying the design/attachments of a W-trawl net used in shrimp/prawn fisheries on unwanted catch of subtidal benthic invertebrate. The study was in Moreton Bay (Australia).   COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Unwanted catch overall abundance (1 study): One replicated, paired, controlled study in Moreton Bay found that four designs of W-trawl nets used in shrimp/prawn fisheries caught less non-commercial unwanted catch of crustaceans compared to a traditional Florida Flyer trawl net. OTHERS (1 STUDY) Commercial catch abundance (1 study): One replicated, paired, controlled study in Moreton Bay found that four designs of W-trawl nets used in shrimp/prawn fisheries caught lower amounts of the commercially targeted prawn species compared to a traditional Florida Flyer trawl net. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2139https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2139Tue, 22 Oct 2019 11:00:22 +0100Collected Evidence: Collected Evidence: Reduce the number or modify the arrangement of tickler chains/chain mats on trawl nets Three studies examined the effects of reducing the number or modifying the arrangement of tickler chains/chain mats on subtidal benthic invertebrates. All studies were in the North Sea (Germany and Netherlands).   COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (3 STUDIES) Overall abundance (1 study): One replicated, paired, controlled study in the North Sea found that using a beam trawl with a chain mat caused lower mortality of benthic invertebrates in the trawl tracks compared to using a beam trawl with tickler chains. Unwanted catch abundance (2 studies): One of two replicated, paired, controlled studies in the North Sea found that all three modified parallel tickler chain arrangements reduced the combined amount of non-commercial unwanted invertebrate and fish catch compared to unmodified trawl nets, but the other found that none of three modified parabolic tickler chain arrangements reduced it. OTHER (2 STUDIES) Commercial catch abundance (2 studies): One of two replicated, paired, controlled studies in the North Sea found that three modified parabolic tickler chain arrangements caught similar amounts of commercial species to unmodified nets, but the other found that three modified parallel tickler chain arrangements caught lower amounts. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2140https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2140Tue, 22 Oct 2019 11:02:53 +0100Collected Evidence: Collected Evidence: Use a larger mesh size on trammel nets One study examined the effects of using a larger mesh size on trammel nets on subtidal benthic invertebrates. The study was in the North Atlantic Ocean (Portugal).   COMMUNITY RESPONSE (1 STUDY) Unwanted catch community composition (1 study): One replicated, controlled, study in the North Atlantic Ocean found that using larger mesh sizes in the inner and/or outer panels of trammel nets did not affect the community composition of unwanted catch of non-commercial invertebrates (discard). POPULATION RESPONSE (1 STUDY) Unwanted catch abundance (1 study): One replicated, controlled, study in the North Atlantic Ocean found that using larger mesh sizes in the inner and/or outer panels of trammel nets did not reduce the abundance of unwanted catch of non-commercial invertebrates (discard). Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2141https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2141Tue, 22 Oct 2019 11:07:22 +0100Collected Evidence: Collected Evidence: Use traps instead of fishing nets One study examined the effects of using traps instead of fishing nets on subtidal benthic invertebrates. The study took place in the Mediterranean Sea (Spain).   COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Unwanted catch abundance (1 study): One replicated, controlled study in the Mediterranean Sea found that the combined amount of unwanted catch of invertebrates and fish appeared lower using plastic traps than trammel nets, but higher using collapsible traps. OTHER (1 STUDY) Commercial catch abundance (1 study): One replicated, controlled study in the Mediterranean Sea found that the catch of commercially targeted lobsters was lower using traps than in trammel nets. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2142https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2142Tue, 22 Oct 2019 11:08:46 +0100Collected Evidence: Collected Evidence: Modify the design of traps Two studies examined the effects of modifying the design of traps on subtidal benthic invertebrates. One study took place in the Mediterranean Sea (Spain), and one in the South Pacific Ocean (New Zealand).   COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (2 STUDIES) Unwanted catch abundance (2 studies): Two replicated, controlled studies in the Mediterranean Sea and the South Pacific Ocean found that the amount of combined unwanted catch of invertebrates and fish varied with the type of trap design used and the area. OTHER (1 STUDY) Commercial catch abundance (1 study): One replicated, controlled study in the Mediterranean Sea found that plastic traps caught some legal-size commercially targeted lobsters while collapsible traps caught none. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2143https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2143Tue, 22 Oct 2019 11:11:24 +0100Collected Evidence: Collected Evidence: Modify the position of traps Two studies examined the effects of modifying the position of traps on subtidal benthic invertebrate populations. One study was in the Varangerfjord (Norway), the other in the North Atlantic Ocean (Spain).   COMMUNITY RESPONSE (1 STUDY) Unwanted catch species richness/diversity (1 study): One replicated, controlled study in the North Atlantic found that semi-floating traps caught fewer unwanted catch species compared to standard bottom traps. POPULATION RESPONSE (2 STUDIES) Unwanted catch abundance (2 studies): Two replicated, controlled studies in the Varangerfjord and the North Atlantic found that floating or semi-floating traps caught fewer unwanted invertebrates compared to standard bottom traps. OTHER (2 STUDIES) Commercial catch abundance (2 studies): Two replicated, controlled studies in the Varangerfjord and the North Atlantic found that floating or semi-floating traps caught similar amounts (abundance and biomass) of commercially targeted species as standard bottom traps. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2144https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2144Tue, 22 Oct 2019 11:14:51 +0100Collected Evidence: Collected Evidence: Use different bait species in traps One study examined the effects of using different bait species in traps on subtidal benthic invertebrates. The study took place in the South Pacific Ocean (New Zealand).   COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Unwanted catch abundance (1 study): One replicated, controlled study in the South Pacific Ocean found that the type of bait used in fishing pots did not change the amount of unwanted invertebrates caught. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2145https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2145Tue, 22 Oct 2019 11:16:22 +0100Collected Evidence: Collected Evidence: Release live unwanted catch first before handling commercial species We found no studies that evaluated the effects of releasing live unwanted catch first before handling commercial species on subtidal benthic invertebrate populations.   ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this intervention during our systematic journal and report searches. Therefore, we have no evidence to indicate whether or not the intervention has any desirable or harmful effects.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2150https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2150Tue, 22 Oct 2019 11:21:55 +0100Collected Evidence: Collected Evidence: Modify harvest methods of macroalgae We found no studies that evaluated the effects of modifying harvest methods of macroalgae on subtidal benthic invertebrate populations.   ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this intervention during our systematic journal and report searches. Therefore, we have no evidence to indicate whether or not the intervention has any desirable or harmful effects.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2151https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2151Tue, 22 Oct 2019 11:22:45 +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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