Collected Evidence: Collected Evidence: Cease or prohibit static fishing gear We found no studies that evaluated the effects of ceasing or prohibiting static fishing gear 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%2F2103https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2103Tue, 22 Oct 2019 09:29:55 +0100Collected Evidence: Collected Evidence: Establish territorial user rights for fisheries One study examined the effects of establishing territorial user rights for fisheries on subtidal benthic invertebrate populations. The study was in the South Pacific Ocean (Chile).   COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Mollusc reproductive success (1 study): One site comparison study in South Pacific Ocean found that an area with territorial user rights for fisheries had larger-sized and more numerous egg capsules, and more larvae of the Chilean abalone up to 21 months after establishing fishing restrictions compared to an open-access area. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2104https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2104Tue, 22 Oct 2019 09:32:32 +0100Collected Evidence: Collected Evidence: Set commercial catch quotas We found no studies that evaluated the effects of setting commercial 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%2F2105https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2105Tue, 22 Oct 2019 09:33:24 +0100Collected Evidence: Collected Evidence: Set habitat credits systems We found no studies that evaluated the effects of setting habitat credits systems 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%2F2106https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2106Tue, 22 Oct 2019 09:34:13 +0100Collected Evidence: Collected Evidence: Set commercial catch quotas and habitat credits systems We found no studies that evaluated the effects of setting commercial catch quotas and habitat credits systems 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%2F2107https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2107Tue, 22 Oct 2019 09:34:53 +0100Collected Evidence: Collected Evidence: Limit the number of fishing days We found no studies that evaluated the effects of limiting the number of fishing days 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%2F2108https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2108Tue, 22 Oct 2019 09:35:36 +0100Collected Evidence: Collected Evidence: Limit the number of fishing vessels We found no studies that evaluated the effects of limiting the number of fishing vessels 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%2F2109https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2109Tue, 22 Oct 2019 09:36:55 +0100Collected Evidence: Collected Evidence: Limit the number of traps per fishing vessels We found no studies that evaluated the effects of limiting the number of traps per fishing vessels 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%2F2110https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2110Tue, 22 Oct 2019 09:37:40 +0100Collected Evidence: Collected Evidence: Limit the density of traps We found no studies that evaluated the effects of limiting the density of traps 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%2F2111https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2111Tue, 22 Oct 2019 09:38:18 +0100Collected Evidence: Collected Evidence: Install physical barriers to prevent trawling One study examined the effects of installing physical barriers to prevent trawling on subtidal benthic invertebrate populations. The study was in the Bay of Biscay (Spain).   COMMUNITY RESPONSE (1 STUDY) Overall community composition (1 study): One before-and-after study in the Bay of Biscay found that one to four years after installing artificial reefs as physical barriers to prevent trawling invertebrate community composition changed. POPULATION RESPONSE (1 STUDY) Overall abundance (1 study): One before-and-after study in the Bay of Biscay found that one to four years after installing artificial reefs as physical barriers to prevent trawling overall invertebrate biomass increased. Echinoderm abundance (1 study): One before-and-after study in the Bay of Biscay found that one to four years after installing artificial reefs as physical barriers to prevent trawling the biomass of sea urchins and starfish increased. Molluscs abundance (1 study): One before-and-after study in the Bay of Biscay found that one to four years after installing artificial reefs as physical barriers to prevent trawling the biomass of gastropods (sea snails), of one species of cuttlefish, and of two species of octopus increased. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2112https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2112Tue, 22 Oct 2019 09:40:04 +0100Collected Evidence: Collected Evidence: Introduce catch shares We found no studies that evaluated the effects of introducing catch shares 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%2F2113https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2113Tue, 22 Oct 2019 09:43:38 +0100Collected Evidence: Collected Evidence: Purchase fishing permits and/or vessels from fishers We found no studies that evaluated the effects of purchasing fishing permits and/or vessels from fishers 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%2F2114https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2114Tue, 22 Oct 2019 09:44:16 +0100Collected 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 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%2F2115https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2115Tue, 22 Oct 2019 09:46:37 +0100Collected 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: Hand harvest instead of using a dredge Two studies examined the effects of hand harvesting instead of using a dredge on subtidal benthic invertebrate populations. Both were in San Matías Gulf, South Atlantic Ocean (Argentina).   COMMUNITY RESPONSE (2 STUDIES) Unwanted catch community composition (1 study): One replicated, controlled study in San Matías Gulf found that, when harvesting mussels, the community composition of the unwanted catch was similar by hand harvesting and by using a dredge. Unwanted catch richness/diversity (1 study): One replicated, controlled study in San Matías Gulf found that, when harvesting mussels, hand harvesting caught fewer species of unwanted catch compared to using a dredge. POPULATION RESPONSE (2 STUDIES) Unwanted catch abundance (1 study): One replicated, controlled study in San Matías Gulf found that, when harvesting mussels, hand harvesting caught fewer unwanted sea urchins and brittle stars compared to using a dredge. Unwanted catch condition (1 study): One replicated, controlled study in San Matías Gulf found that, when harvesting mussels, the damage caused to unwanted sea urchins and brittle stars was similar by hand harvesting and by using a dredge. OTHER 1 STUDY) Commercial catch abundance (1 study): One replicated, controlled study in San Matías Gulf found that more commercially targeted mussels were caught by hand harvesting than by using a dredge. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2121https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2121Tue, 22 Oct 2019 10:13:22 +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 +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