Collected Evidence: Collected Evidence: Introduce agri-environment schemes to benefit wild beesFour replicated trials in Europe have shown enhanced diversity and/or abundance of foraging wild bees on land managed under various European agri-environment schemes, relative to conventionally-managed fields or field margins. These schemes were the Swiss Ecological Compensation Areas (one replicated trial), the German organic arable farming option (one replicated trial), the Dutch botanical and meadow bird agreements (one replicated trial, very low numbers of bee species) and the Scottish Rural Stewardship Scheme (one replicated trial, also included nest-searching queen bumblebees). Four replicated trials in Europe found that the number of bees and/or bee species is not enhanced on land managed under agri-environment schemes, including meadow bird agreements in wet grassland in the Netherlands, measures to protect steppe-living birds and compensation measures around a National Park in Spain, and 6 m wide grass field margin strips in England (one replicated trial for each). On a wider landscape scale, two replicated trials in the UK have found bumblebee populations were not enhanced on farmland managed under agri-environment schemes. One trial compared the reproductive success of colonies of the buff-tailed bumblebee Bombus terrestris, the other compared queen bumblebee numbers in spring in conventionally managed field margins, on farms with and without agri-environment schemes.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F24https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F24Thu, 20 May 2010 16:11:07 +0100Collected Evidence: Collected Evidence: Introduce and enforce legislation to control hunting of bats We found no studies that evaluated the effects of introducing and enforcing legislation to control the hunting of bats on bat populations. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F984https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F984Fri, 20 Dec 2013 14:29:41 +0000Collected Evidence: Collected Evidence: Introduce and enforce legislation to regulate harvesting of bat guano We found no studies that evaluated the effects of introducing and enforcing legislation to regulate the harvesting of bat guano on bat populations. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F987https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F987Fri, 20 Dec 2013 14:32:49 +0000Collected Evidence: Collected Evidence: Introduce beavers to impede water flow in forest watercourses We found no evidence for the effects of introducing beavers to impede water flow in forest watercourses on forests. 'No evidence' for an action means we have not yet found any studies that directly and quantitatively tested this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1187https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1187Thu, 19 May 2016 11:46:07 +0100Collected Evidence: Collected Evidence: Introduce ammunition tax We found no evidence for the effects of introducing ammunition tax on primate populations. 'No evidence' for an action means we have not yet found any studies that directly and quantitatively tested this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1473https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1473Tue, 17 Oct 2017 16:54:34 +0100Collected Evidence: Collected Evidence: Introduce an organism to control problematic plants One study evaluated the effects, on peatland vegetation, of introducing an organism (other than large vertebrate grazers) to control problematic plants. The study was in a fen meadow. Plant community composition (1 study): One controlled, before-and-after study in a fen meadow in Belgium found that introducing a parasitic plant altered the overall plant community composition. Vegetation cover (1 study): The same study found that introducing a parasitic plant reduced cover of the dominant sedge but increased moss cover. Overall plant richness/diversity (1 study): The same study found that introducing a parasitic plant increased overall plant species richness. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1777https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1777Mon, 27 Nov 2017 21:44:50 +0000Collected Evidence: Collected Evidence: Introduce alternative treatments to reduce the use of bats in traditional medicine We found no studies that evaluated the effects of introducing alternative treatments to reduce the use of bats in traditional medecine on bat populations. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1975https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1975Tue, 04 Dec 2018 18:24:01 +0000Collected 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: Introduce and enforce legislation to prevent intentional killing of mammals at aquaculture systems We found no studies that evaluated the effects of introducing and enforcing legislation to prevent intentional killing of mammals at aquaculture systems. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2745https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2745Tue, 02 Feb 2021 16:43:17 +0000Collected Evidence: Collected Evidence: Introduce and enforce regulations to prevent the use of harmful deterrents on mammals at aquaculture systems We found no studies that evaluated the effects of introducing and enforcing regulations to prevent the use of harmful deterrents on mammals at aquaculture systems. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2746https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2746Tue, 02 Feb 2021 16:45:37 +0000Collected Evidence: Collected Evidence: Introduce and enforce legislation to prevent intentional killing of mammals at wild fisheries We found no studies that evaluated the effects of introducing and enforcing legislation to prevent intentional killing of mammals at wild fisheries. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2778https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2778Thu, 04 Feb 2021 15:51:27 +0000Collected Evidence: Collected Evidence: Introduce and enforce regulations to prevent the use of harmful deterrents on mammals at wild fisheries We found no studies that evaluated the effects of introducing and enforcing regulations to prevent the use of harmful deterrents on mammals at wild fisheries. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2779https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2779Thu, 04 Feb 2021 15:59:06 +0000Collected Evidence: Collected Evidence: Introduce alternative treatments to reduce the use of marine and freshwater mammals in traditional medicine We found no studies that evaluated the effects of introducing alternative treatments to reduce the use of marine and freshwater mammals in traditional medicine. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2783https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2783Thu, 04 Feb 2021 16:19:10 +0000Collected Evidence: Collected Evidence: Introduce alternative food sources to replace marine and freshwater mammal meat We found no studies that evaluated the effects of introducing alternative food sources to replace marine and freshwater mammal meat. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2784https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2784Thu, 04 Feb 2021 16:21:34 +0000Collected Evidence: Collected Evidence: Introduce alternative income sources to reduce marine and freshwater mammal exploitation and trade We found no studies that evaluated the effects of introducing alternative income sources to reduce marine and freshwater mammal exploitation and trade. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2785https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2785Thu, 04 Feb 2021 16:22:40 +0000Collected Evidence: Collected Evidence: Introduce alternative sources of bait to replace the use of marine and freshwater mammals We found no studies that evaluated the effects of introducing alternative sources of bait to replace the use of marine and freshwater mammals. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2786https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2786Thu, 04 Feb 2021 16:23:36 +0000Collected Evidence: Collected Evidence: Introduce and enforce regulations for sustainable hunting of marine and freshwater mammals for traditional subsistence and handicrafts We found no studies that evaluated the effects of introducing regulations for sustainable hunting of marine and freshwater mammals for traditional subsistence and handicrafts. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2789https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2789Thu, 04 Feb 2021 16:26:55 +0000Collected Evidence: Collected Evidence: Introduce and enforce regulations for marine and freshwater mammal watching tours Four studies evaluated the effects of introducing regulations for marine and freshwater mammal watching tours on marine mammals. One study was in each of the North Atlantic Ocean (the Azores), the Cananéia estuary (Brazil), the South Pacific Ocean (Australia) and the Bass Strait (Australia). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (4 STUDIES) Behaviour change (4 studies): Two controlled studies in the North Atlantic Ocean and South Pacific Ocean found that when whale-watching vessels followed approach regulations, fewer sperm whales and humpback whale pods changed their behaviours (e.g. swimming speed, aerial displays) or avoided the vessels compared to when regulations were not followed, but direction of movement and diving patterns or diving behaviours did not differ. One replicated, controlled study in the Cananéia estuary found that when tour boats followed approach regulations, fewer Guiana dolphins displayed negative behaviours (e.g. moving away, diving, groups separating). One study in the Bass Strait found that when boats approached a seal colony to 75 m, more seals remained on shore than when boats approached to 25 m. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2838https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2838Fri, 05 Feb 2021 16:16:26 +0000Collected Evidence: Collected Evidence: Introduce and enforce water quality regulations for aquaculture systems We found no studies that evaluated the effects of introducing and enforcing water quality regulations for aquaculture systems on marine and freshwater mammal populations. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2876https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2876Mon, 08 Feb 2021 11:41:53 +0000Collected Evidence: Collected Evidence: Introduce alternative income sources to replace hunting or harvesting of reptiles One study evaluated the effects on reptile populations of introducing alternative income sources to replace hunting or harvesting of reptile populations. This study was in St Kitts1. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (1 STUDY) Human behaviour change (1 study): One before-and-after study in St Kitts1 found that fishers that took jobs on a turtle management project reported that they ceased turtle fishing activity. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3542https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3542Tue, 07 Dec 2021 17:10:17 +0000Collected Evidence: Collected Evidence: Introduce and enforce water quality regulations for aquaculture systems We found no studies that evaluated the effects on reptile populations of introducing and enforcing water quality regulations for aquaculture systems. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3581https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3581Wed, 08 Dec 2021 15:26:09 +0000Collected Evidence: Collected Evidence: Introduce and enforce regulations for reptile watching tours We found no studies that evaluated the effects on reptile populations of introducing and enforcing regulations for reptile watching tours. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3644https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3644Thu, 09 Dec 2021 15:30:41 +0000Collected Evidence: Collected Evidence: Introduce an overall catch limit (quota cap or total allowable catch) by fishery or fleet Nine studies examined the effects of introducing overall catch limits by fishery or fleet on marine fish populations. Three studies were worldwide, two studies were in the South Atlantic Ocean (Namibia/South Africa), two studies were in the North Sea (Northern Europe), and one study was in each of the North Sea and Atlantic Ocean (Scotland) and the North Atlantic Ocean (Canada).   COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (6 STUDIES) Abundance (5 studies): Four before-and-after studies (two replicated) in the South Atlantic Ocean, the North Atlantic Ocean and the North Sea reported that following the introduction of overall catch limits for fish there was a higher abundance or biomass of hakes, Atlantic herring and Atlantic halibut, compared to before. One replicated, controlled study of fish stocks worldwide found that overfished stocks of tunas and billfishes had faster increases of biomass when managed using overall catch limits, compared to stocks with other types of control or no management. Reproductive success (1 study): A global review reported that after overall catch limits and minimum landing size were introduced there was strong recruitment of broadbill swordfish for one key stock, while recruitment for four other stocks could not be assessed due to limited data. Survival (2 studies): One before-and-after study and one replicated, controlled study in the North Atlantic Ocean and worldwide found that for fish species with overall catch limits there was a decrease or lower fishing mortality, compared either to before implementation or to stocks without catch limits and those with other controls. BEHAVIOUR (0 STUDIES) OTHER (3 STUDIES) Reduction of unwanted catch (1 study): One replicated, before-and-after study in the North Sea and North Atlantic Ocean found that overall catch limits did not reduce unwanted megrim catch despite a reduction in discards, however this was due to retention of more small but legal-sized megrim, previously discarded. Reduction of fishing effort (1 study): One replicated, before-and-after study in the North Sea found that when annual total allowable catch limits were changed (increased or decreased), half of the otter trawl fleet had corresponding changes in fishing effort (increased or decreased), but there were no changes for the beam trawl fleet. Stock status (1 study): One global systematic review found that in terms of reaching biomass-based management targets fisheries with fleet-wide catch quotas were no different to fisheries managed either by catch shares or effort controls. However, along with catch share fisheries, fewer catch quota stocks were over-exploited than those with effort controls. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3811https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3811Thu, 26 May 2022 15:07:14 +0100Collected Evidence: Collected Evidence: Introduce catch shares Two studies examined the effects of introducing catch shares on marine fish populations. Both were reviews of fisheries worldwide.   COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (2 STUDIES) Abundance (2 studies): One of two worldwide systematic reviews found that fisheries or stocks managed under catch shares were more likely to meet management target levels for biomass sustainability than those that did not meet targets. The other study found there was no difference in performance of biomass-based management targets between fisheries under catch shares, fleet-wide catch caps or fishing effort controls. BEHAVIOUR (0 STUDIES) OTHER (2 studies) Stock status (2 studies): Two worldwide systematic reviews found that catch share fisheries had lower rates of over-exploitation compared to non-catch share fisheries, and a higher proportion of fisheries managed under catch shares either met or exceeded management target levels for rates of exploitation than those that did not meet targets. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3812https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3812Fri, 27 May 2022 08:20:03 +0100Collected Evidence: Collected Evidence: Introduce a pause when hauling dredge gear We found no studies that evaluated the effects of introducing a pause when hauling dredge gear 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%2Fwww.conservationevidence.com%2Factions%2F3829https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3829Fri, 27 May 2022 10:36:30 +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.

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