Conservation Evidence: Evidence Data

Collected 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: 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%2Fwww.conservationevidence.com%2Factions%2F2131https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2131Tue, 22 Oct 2019 10:27:16 +0100Collected Evidence: Collected Evidence: Fit one or more mesh escape panels/windows to trawl nets Seven studies examined the effects of adding one or more mesh escape panels/windows to trawl nets on subtidal benthic invertebrate populations. Six were in the North Sea (Belgium, Netherlands, UK), two in the Thames estuary (UK), one in the English Channel (UK), and one in the Gulf of Carpentaria (Australia). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (7 STUDIES) Overall survival (1 study): One replicated, paired, controlled study in the English Channel and the North Sea found that fitting nets with either one of seven designs of square mesh escape panels (varying mesh size and twine type) led to higher survival rates of invertebrates that escaped the nets compared to unmodified nets. Unwanted catch overall abundance (7 studies): Three of seven replicated, paired, controlled studies in the North Sea, the Thames estuary, the English Channel and the Gulf of Carpentaria found that trawl nets fitted with one or more mesh escape panels/windows/zones reduced the unwanted catch of invertebrates compared to unmodified nets. Two found mixed effects of fitting escape panels on the unwanted catch of invertebrates and fish depending on the panel design. Two found that trawl nets fitted with escape panels caught similar amounts of unwanted invertebrates and fish compared to unmodified nets. OTHERS (7 STUDIES) Commercially targeted catch abundance (7 studies): Three of seven replicated, paired, controlled studies in the North Sea, the Thames estuary, the English Channel and the Gulf of Carpentaria, found that trawl nets fitted with one or more mesh escape panels/windows/zones caught similar amounts of all or most commercial species to unmodified nets. Three found mixed effects of fitting escape panels on the catch of all or most commercial species depending on the species and/or panel design. One found that trawl nets fitted with escape panels reduced the catch of commercial species compared to unmodified nets. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2132https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2132Tue, 22 Oct 2019 10:33:29 +0100Collected Evidence: Collected Evidence: Fit one or more soft, semi-rigid, or rigid grids or frames to trawl nets Two studies examined the effects of fitting one or more soft, semi-rigid, or rigid grids or frames to trawl nets on subtidal benthic invertebrate populations. The studies were in the Gulf of Carpentaria and Spencer Gulf (Australia). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (2 STUDIES) Unwanted catch abundance (1 study): Two replicated, paired, controlled studies in the Gulf of Carpentaria and in Spencer Gulf found that nets fitted with a ‘downward’-oriented grid but not an ‘upward’-oriented grid reduced the weight of small unwanted catch and that both grid orientations caught fewer unwanted large sponges, and that nets fitted with two sizes of grids reduced the number and biomass of unwanted blue swimmer crabs and giant cuttlefish caught, compared to unmodified nets. OTHER (2 STUDIES) Commercial catch abundance (2 studies): Two replicated, paired, controlled studies in the Gulf of Carpentaria and Spencer Gulf found that nets fitted with a ‘downward’-oriented grid or a small grid reduced the catch of commercially targeted prawns, compared to unmodified nets, but those fitted with an ‘upward’-oriented grid or a large grid caught similar amounts to unmodified nets. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2133https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2133Tue, 22 Oct 2019 10:46:29 +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%2Fwww.conservationevidence.com%2Factions%2F2134https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2134Tue, 22 Oct 2019 10:52:46 +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%2Fwww.conservationevidence.com%2Factions%2F2137https%3A%2F%2Fwww.conservationevidence.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%2Fwww.conservationevidence.com%2Factions%2F2138https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2138Tue, 22 Oct 2019 10:59:13 +0100Collected Evidence: Collected Evidence: Fit one or more soft, semi-rigid, or rigid grids or frames on pots and traps One study examined the effects of fitting one or more soft, semi-rigid, or rigid grids or frames on pots and traps on subtidal benthic invertebrates. The study took place in the Corindi River system (Australia). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Unwanted catch abundance (1 study): One replicated, controlled study in the Corindi River system found that traps fitted with escape frames appeared to reduce the proportion of unwanted undersized mud crabs caught, compared to conventional traps without escape frames. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2146https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2146Tue, 22 Oct 2019 11:17:56 +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%2Fwww.conservationevidence.com%2Factions%2F2147https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2147Tue, 22 Oct 2019 11:18:38 +0100Collected Evidence: Collected Evidence: Increase the mesh size of pots and traps One study examined the effects of increasing the mesh size of pots and traps on subtidal benthic invertebrates. The study took place in the Corindi River system (Australia). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Unwanted catch abundance (1 study): One replicated, controlled study in the Corindi River system found that traps designed with larger mesh appeared to reduce the proportion of unwanted undersized mud crabs caught, compared to conventional traps of smaller mesh. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2148https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2148Tue, 22 Oct 2019 11:20:04 +0100Collected Evidence: Collected Evidence: Fit one or more soft, semi-rigid, or rigid grids or frames and increase the mesh size of pots and traps One study examined the effects of fitting one or more soft, semi-rigid, or rigid grids or frames and increasing the mesh size of pots and traps on subtidal benthic invertebrates. The study took place in the Corindi River system (Australia). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Unwanted catch abundance (1 study): One replicated, controlled study in the Corindi River system found that traps fitted with escape frames and designed with larger mesh appeared to reduce the proportion of unwanted undersized mud crabs caught, compared to conventional traps without escape frames and smaller mesh. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2149https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2149Tue, 22 Oct 2019 11:21:17 +0100