Collected Evidence: Collected Evidence: Use acoustic devices at aquaculture systems Six studies evaluated the effects on marine and freshwater mammals of using acoustic devices at aquaculture systems. Four studies were in the North Atlantic Ocean (USA, UK), one was in the Reloncaví fjord (Chile) and one in the Mediterranean Sea (Italy). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (6 STUDIES) Human-wildlife conflict (6 studies): Four of six studies (including five before-and-after and/or site comparison studies and one controlled study) in the North Atlantic Ocean, the Reloncaví fjord and the Mediterranean Sea found that using acoustic devices at salmon farms reduced predation on caged salmon by grey seals, harbour seals and South American sea lions, or reduced the number of harbour seals approaching a fish cage. The two other studies found that using acoustic devices did not reduce harbour seal predation at salmon farms, or reduce the presence, approach distances, groups sizes or time spent around fin-fish farms by common bottlenose dolphins. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2775https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2775Thu, 04 Feb 2021 15:29:04 +0000Collected Evidence: Collected Evidence: Translocate mammals away from aquaculture systems to reduce human-wildlife conflict Two studies evaluated the effects of translocating mammals away from aquaculture systems to reduce human-wildlife conflict. Both studies were in the Tasman Sea and one was also in the Southern Ocean (Tasmania). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES)       OTHER (2 STUDIES) Human-wildlife conflict (2 studies): Two studies (including one site comparison study) in the Tasman Sea (one also in the Southern Ocean) found that more than half or nearly all of Australian and New Zealand fur seals translocated away from salmon farms returned. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2776https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2776Thu, 04 Feb 2021 15:43:44 +0000Collected Evidence: Collected Evidence: Set and enforce vessel speed limits Two studies evaluated the effects on marine and freshwater mammals of setting and enforcing vessel speed limits. One study was in the Indian River estuarine system (USA) and the other in the North Atlantic Ocean (USA). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (2 STUDIES) Survival (2 studies): One before-and-after study in the Indian River estuarine system found similar numbers of manatee deaths before and after vessel speed limits were set in ‘zones’, but fewer deaths were recorded after speed limits were set and enforced in all areas. One before-and-after study in the North Atlantic Ocean found that setting vessel speed limits during specific periods in key habitats resulted in fewer North Atlantic right whale deaths caused by collisions. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2777https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2777Thu, 04 Feb 2021 15:48:43 +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: Prohibit or restrict hunting of marine and freshwater mammal species Five studies evaluated the effects of prohibiting hunting of marine mammal species. One study was in each of the Kattegat and Skagerrak seas (Denmark and Sweden), the North Atlantic Ocean, North Pacific Ocean and the Southern Hemisphere, the South Pacific Ocean (Australia), the North Atlantic Ocean (Greenland) and the Southern Ocean (Australia). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (5 STUDIES) Abundance (5 studies): Four of five studies (including three before-and-after studies) in the Kattegat and Skagerrak Seas, the South Pacific Ocean, the North Atlantic Ocean and the Southern Ocean found that after hunting was prohibited, the abundance of harbour seals and humpback whales increased over 7–30 years. The other study found that numbers of mature male sperm whales did not differ significantly before or 31 years after hunting was prohibited. One review in the North Atlantic Ocean, North Pacific Ocean and the Southern Hemisphere found significant increase rates for 10 of 12 baleen whale populations during 7–21 years after legislation to prohibit hunting was introduced. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2780https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2780Thu, 04 Feb 2021 16:09:52 +0000Collected Evidence: Collected Evidence: Enforce legislation to prevent the trafficking and trade of marine and freshwater mammal products We found no studies that evaluated the effects of enforcing legislation to prevent the trafficking and trade of marine and freshwater mammal products. ‘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%2F2781https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2781Thu, 04 Feb 2021 16:16:18 +0000Collected Evidence: Collected Evidence: Restrict capture of marine and freshwater mammals for research or aquariums and zoos We found no studies that evaluated the effects of restricting capture of marine and freshwater mammals for research or aquariums and zoos. ‘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%2F2782https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2782Thu, 04 Feb 2021 16:17:27 +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: Inform local communities and fishers about the negative impacts of hunting to reduce the killing of marine and freshwater mammals We found no studies that evaluated the effects of informing local communities and fishers about the negative impacts of hunting to reduce the killing 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%2F2787https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2787Thu, 04 Feb 2021 16:24:44 +0000Collected Evidence: Collected Evidence: Educate local communities and fishers on mammal protection laws to reduce killing of marine and freshwater mammals We found no studies that evaluated the effects of educating local communities and fishers on mammal protection laws to reduce killing 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%2F2788https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2788Thu, 04 Feb 2021 16:26:07 +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: Establish ‘move-on rules’ for fishing vessels if mammals are encountered One study evaluated the effects on marine mammals of establishing move-on rules for fishing vessels if mammals are encountered. The study was in the Great Australian Bight (Australia). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Survival (1 study): One before-and-after study in the Great Australian Bight found that introducing measures to delay or relocate fishing if dolphins were encountered, along with releasing trapped dolphins, resulted in fewer short-beaked common dolphins being encircled and killed. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2790https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2790Thu, 04 Feb 2021 16:29:13 +0000Collected Evidence: Collected Evidence: Use passive listening devices to detect mammals and prompt fishing vessels to move away We found no studies that evaluated the effects of using passive listening devices to detect mammals and prompt fishing vessels to move away 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%2F2791https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2791Thu, 04 Feb 2021 16:30:32 +0000Collected Evidence: Collected Evidence: Deploy fishing gear at times when mammals are less active We found no studies that evaluated the effects of deploying fishing gear at times when mammals are less active 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%2F2792https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2792Thu, 04 Feb 2021 16:31:14 +0000Collected Evidence: Collected Evidence: Deploy fishing gear at different depths One study evaluated the effects on marine mammals of deploying fishing gear at different depths. The study was in the Arafura Sea (Australia). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (1 STUDY) Reduction in entanglements/unwanted catch (1 study): One controlled study in the Arafura Sea found that fishing nets deployed 4.5 m below the water surface had fewer entanglements of dolphins than surface nets. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2793https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2793Thu, 04 Feb 2021 16:33:47 +0000Collected Evidence: Collected Evidence: Limit the number of fishing vessels or fishing days in an area We found no studies that evaluated the effects of limiting the number of fishing vessels or fishing days in an area 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%2F2794https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2794Thu, 04 Feb 2021 16:36:53 +0000Collected Evidence: Collected Evidence: Limit the length of fishing gear in an area We found no studies that evaluated the effects of limiting the length of fishing gear in an area 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%2F2795https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2795Thu, 04 Feb 2021 16:37:57 +0000Collected Evidence: Collected Evidence: Reduce duration of time fishing gear is in the water We found no studies that evaluated the effects of reducing the duration of time fishing gear is in the water 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%2F2796https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2796Thu, 04 Feb 2021 16:38:40 +0000Collected Evidence: Collected Evidence: Use weakened fishing gear We found no studies that evaluated the effects of using weakened fishing gear 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%2F2797https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2797Thu, 04 Feb 2021 16:39:26 +0000Collected Evidence: Collected Evidence: Retain buoys and lines at the sea floor or river bed when not hauling We found no studies that evaluated the effects of retaining buoys and lines at the sea floor or river bed when not hauling 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%2F2798https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2798Thu, 04 Feb 2021 16:40:23 +0000Collected Evidence: Collected Evidence: Use sinking lines instead of floating lines We found no studies that evaluated the effects of using sinking lines instead of floating lines 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%2F2799https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2799Thu, 04 Feb 2021 16:41:08 +0000
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