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%2Fconservationevidencejournal.com%2Factions%2F2116https%3A%2F%2Fconservationevidencejournal.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%2Fconservationevidencejournal.com%2Factions%2F2117https%3A%2F%2Fconservationevidencejournal.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%2Fconservationevidencejournal.com%2Factions%2F2118https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2118Tue, 22 Oct 2019 09:49:40 +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%2Fconservationevidencejournal.com%2Factions%2F2120https%3A%2F%2Fconservationevidencejournal.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%2Fconservationevidencejournal.com%2Factions%2F2122https%3A%2F%2Fconservationevidencejournal.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%2Fconservationevidencejournal.com%2Factions%2F2123https%3A%2F%2Fconservationevidencejournal.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%2Fconservationevidencejournal.com%2Factions%2F2124https%3A%2F%2Fconservationevidencejournal.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%2Fconservationevidencejournal.com%2Factions%2F2125https%3A%2F%2Fconservationevidencejournal.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%2Fconservationevidencejournal.com%2Factions%2F2126https%3A%2F%2Fconservationevidencejournal.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%2Fconservationevidencejournal.com%2Factions%2F2127https%3A%2F%2Fconservationevidencejournal.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%2Fconservationevidencejournal.com%2Factions%2F2128https%3A%2F%2Fconservationevidencejournal.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%2Fconservationevidencejournal.com%2Factions%2F2129https%3A%2F%2Fconservationevidencejournal.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%2Fconservationevidencejournal.com%2Factions%2F2130https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2130Tue, 22 Oct 2019 10:26:05 +0100Collected Evidence: Collected Evidence: Fit a funnel (such as a sievenet) or other escape devices on shrimp/prawn trawl nets One study examined the effects of fitting a funnel, sievenet, or other escape devices on trawl nets on marine subtidal invertebrate. The study was in the North Sea (UK).   COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Unwanted catch abundance (1 study): One replicated, paired, controlled study in the North Sea found that trawl nets fitted with a sievenet appeared to catch fewer unwanted catch of non-commercial invertebrates compared to unmodified nets. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2131https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2131Tue, 22 Oct 2019 10:27:16 +0100Collected Evidence: Collected Evidence: Fit one or more mesh escape panels/windows and one or more soft, rigid or semi-rigid grids or frames to trawl nets One study examined the effects on subtidal benthic invertebrate populations of fitting one or more mesh escape panels/windows and one or more soft, rigid or semi-rigid grids or frames to trawl nets . The study was in the Gulf of Carpentaria (Australia).   COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Unwanted catch abundance (1 study): One replicated, paired, controlled study in Gulf of Carpentaria found that trawl nets fitted with an escape window and a grid reduced the total weight of small unwanted catch and caught fewer unwanted large sponges, compared to unmodified nets. OTHER (1 STUDY) Commercial catch abundance (1 study): One replicated, paired, controlled study in Carpentaria found that trawl nets fitted with an escape window and a grid reduced the catch of commercially targeted prawns, compared to unmodified nets. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2134https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2134Tue, 22 Oct 2019 10:52:46 +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%2Fconservationevidencejournal.com%2Factions%2F2135https%3A%2F%2Fconservationevidencejournal.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%2Fconservationevidencejournal.com%2Factions%2F2136https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2136Tue, 22 Oct 2019 10:56:11 +0100Collected Evidence: Collected Evidence: Fit one or more soft, semi-rigid, or rigid grids or frames to trawl nets and use square mesh instead of a diamond mesh at the codend One study examined the effects of fitting one or more soft, semi-rigid, or rigid grids or frames to trawl nets and using a square mesh codend on subtidal benthic invertebrates. The study was in the Gulf of St Vincent (Australia).   COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Unwanted catch abundance (1 study): One replicated, paired, controlled study in Gulf of St Vincent found that trawl nets fitted with a rigid U-shaped grid and a square-oriented mesh codend reduced the catch rates of three dominant groups of unwanted invertebrate catch species, compared to unmodified nets. OTHER (1 STUDY) Commercial catch abundance (1 study): One replicated, paired, controlled study in the Gulf of St Vincent found that trawl nets fitted with a rigid U-shaped grid and a square-oriented mesh codend reduced the catch rates of the commercially targeted western king prawn, due to reduced catch of less valuable smaller-sized prawns, compared to unmodified nets. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2137https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2137Tue, 22 Oct 2019 10:57:05 +0100Collected Evidence: Collected Evidence: Fit one or more mesh escape panels/windows to trawl nets and use a square mesh instead of a diamond mesh codend One study examined the effects of fitting one or more mesh escape panels to trawl nets and using a square mesh instead of a diamond mesh codend on 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 trawl nets fitted with two large square mesh release panels and a square mesh codend caught fewer unwanted catch of non-commercial invertebrates compared to standard trawl nets. OTHER (1 STUDY) Commercial catch abundance (1 study): One replicated, paired, controlled study in the English Channel found that trawl nets fitted with two large square mesh release panels and a square mesh codend caught fewer commercial shellfish, and fewer but more valuable commercially important fish, compared to standard trawl nets. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2138https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2138Tue, 22 Oct 2019 10:59:13 +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%2Fconservationevidencejournal.com%2Factions%2F2139https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2139Tue, 22 Oct 2019 11:00:22 +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%2Fconservationevidencejournal.com%2Factions%2F2141https%3A%2F%2Fconservationevidencejournal.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%2Fconservationevidencejournal.com%2Factions%2F2142https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2142Tue, 22 Oct 2019 11:08:46 +0100Collected Evidence: Collected Evidence: Fit one or more mesh escape panels/windows on pots and traps We found no studies that evaluated the effects of fitting one or more mesh escape panels/windows on pots and 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%2Fconservationevidencejournal.com%2Factions%2F2147https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2147Tue, 22 Oct 2019 11:18:38 +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%2Fconservationevidencejournal.com%2Factions%2F2150https%3A%2F%2Fconservationevidencejournal.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%2Fconservationevidencejournal.com%2Factions%2F2151https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2151Tue, 22 Oct 2019 11:22:45 +0100
What Works 2021 cover

What Works in Conservation

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

More about What Works in Conservation

Download free PDF or purchase
The Conservation Evidence Journal

The Conservation Evidence Journal

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

Read the latest volume: Volume 21

Go to the CE Journal

Discover more on our blog

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

Who uses Conservation Evidence?

Meet some of the evidence champions

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

This website uses Cookies

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

Accept & continue