Collected Evidence: Collected Evidence: Attach acoustically reflective objects to fishing gear Two studies evaluated the effects on marine mammals of attaching acoustically reflective objects to fishing gear. One study was in the Timor Sea and Arafura Sea (Australia) and one was in the Gulf of Alaska (USA). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (2 STUDIES) Reduction in entanglements/unwanted catch (1 study): One controlled study in the Timor Sea and Arafura Sea found that attaching metallic bead chains to fishing nets did not reduce the number of dolphin entanglements. Human-wildlife conflict (1 study): One controlled study in the Gulf of Alaska found that attaching acrylic beads next to fishing hooks did not reduce predation on fish catches by sperm whales. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2806https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2806Thu, 04 Feb 2021 17:20:11 +0000Collected Evidence: Collected Evidence: Carry out surveillance for diseases We found no studies that evaluated the effects of carrying out surveillance for diseases 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%2Fconservationevidencejournal.com%2Factions%2F2857https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2857Mon, 08 Feb 2021 11:14:33 +0000Collected Evidence: Collected Evidence: Add chemicals or minerals to sediment to remove or neutralize pollutants We found no studies that evaluated the effects of adding chemicals or minerals to sediment to remove or neutralize pollutants 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%2Fconservationevidencejournal.com%2Factions%2F2864https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2864Mon, 08 Feb 2021 11:25:33 +0000Collected Evidence: Collected Evidence: Cease or prohibit activities that cause disturbance during sensitive periods for marine and freshwater mammals We found no studies that evaluated the effects of ceasing or prohibiting activities that cause disturbance during sensitive periods for 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%2Fconservationevidencejournal.com%2Factions%2F2918https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2918Mon, 08 Feb 2021 16:34:09 +0000Collected Evidence: Collected Evidence: Breed marine and freshwater mammals in captivity Six studies evaluated the effects of breeding marine and freshwater mammals in captivity. Three studies were in the USA, one study was also in China, Indonesia and Venezuela, and one study was in each of South Africa, Hong Kong and China. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (6 STUDIES) Reproductive success (2 studies): One study in Hong Kong found that four of six female Indo-Pacific dolphins successfully conceived during a controlled captive breeding programme and gave birth to a total of nine calves. One study in China found that wild-caught Yangtze finless porpoises successfully reproduced in semi-captive conditions. Survival (4 studies): Two studies in South Africa and the USA found that a captive-born common bottlenose dolphin, and a captive-born and hand-reared common bottlenose dolphin, survived in captivity for at least two and a half years and four years respectively. One review in the USA found that 80% of common bottlenose dolphins born in captivity over two decades survived, and survival increased with improved husbandry techniques. One review in the USA, China, Indonesia and Venezuela found that most captive-born Amazon river dolphins, narrow-ridged finless porpoises and Irrawaddy dolphins did not survive in captivity. Condition (1 study): One study in China found that a population of Yangtze finless porpoises breeding in semi-captive conditions had low genetic diversity. BEHAVIOUR (1 STUDY) Behaviour change (1 study): One study in the USA found that a captive-born and hand-reared common bottlenose dolphin displayed normal behaviour for the species and joined a dolphin social group in captivity. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2932https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2932Tue, 09 Feb 2021 11:30:25 +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 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