Collected Evidence: Collected Evidence: Use hook and line fishing instead of other commercial fishing methods Three studies examined the effects of using hook and line fishing instead of other commercial fishing methods on marine fish populations. One study was in each of the Tasman Sea (Australia), the Atlantic Ocean (Canada) and the Gulf of St. Lawrence (Canada).  COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Survival (1 study): One replicated, controlled study in the Gulf of St. Lawrence found that fish caught by hook and line methods had greater vitality (an indicator of post-release survival) than fish caught by other gear types. BEHAVIOUR (0 STUDIES) OTHER (2 STUDIES) Reduction of unwanted catch (1 study): One replicated, controlled study in the Tasman Sea found that using longlines reduced the capture of unwanted small snapper, compared to trawling. Improved size-selectivity of fishing gear (1 study): One replicated, paired, controlled study in the Atlantic Ocean found that longlining compared to trawling, increased the size selectivity of cod and haddock at larger hook sizes only. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2732https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2732Thu, 28 Jan 2021 11:49:50 +0000Collected Evidence: Collected Evidence: Release fish that are carrying eggs or live young We found no studies that evaluated the effects of releasing fish that are carrying eggs or live young 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%2F2733https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2733Tue, 02 Feb 2021 12:04:35 +0000Collected Evidence: Collected Evidence: Release males of species known to guard nests during breeding season We found no studies that evaluated the effects of releasing males that guard nests during the breeding season 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%2F2734https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2734Tue, 02 Feb 2021 12:09:39 +0000Collected Evidence: Collected Evidence: Set a minimum landing size for commercially fished species Five studies examined the effects of setting a minimum landing size for commercially fished species on marine fish populations. One study was a global review and one study was in each of the Tasman Sea (Australia), the Baltic Sea (Northern Europe), the Ionian Sea (Greece) and the Northwest Atlantic Ocean (USA). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (2 STUDIES) Reproductive success (2 studies): One global review reported that one of five swordfish fisheries showed an increase in swordfish recruitment after the setting of recommended minimum landing sizes and catch limits, with recruitment in the other fisheries either highly variable or unable to be assessed. One replicated study in the Ionian Sea reported that, despite established minimum sizes, most fish landed in commercial catches were immature, and thus had never spawned. BEHAVIOUR (0 STUDIES) OTHER (3 STUDIES) Reduction of unwanted catch (3 studies): One of three before-and-after studies (one replicated) in the Atlantic Ocean, Tasman Sea and Baltic Sea found that following an increase in the set minimum landing size and mesh size of gill nets the catches of the youngest southern flounder were reduced. The other two found that increasing the minimum landing size did not reduce the catches of discarded dusky flathead and Atlantic cod3, and discarding of flathead increased in one of three cases. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2735https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2735Tue, 02 Feb 2021 14:28:08 +0000Collected Evidence: Collected Evidence: Set a maximum landing size for commercially fished species We found no studies that evaluated the effects of setting a maximum landing size for commercially fished species 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%2F2736https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2736Tue, 02 Feb 2021 14:40:24 +0000Collected Evidence: Collected Evidence: Specify a size range of capture for commercially fished species We found no studies that evaluated the effects of specifying a size range of commercially retained fish species 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%2F2737https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2737Tue, 02 Feb 2021 14:56:52 +0000Collected Evidence: Collected Evidence: Deploy patrol boats We found no studies that evaluated the effects of deploying patrol boats 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%2F2738https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2738Tue, 02 Feb 2021 15:08:05 +0000Collected Evidence: Collected Evidence: Organise vessel monitoring systems We found no studies that evaluated the effects of organising monitoring systems 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%2F2739https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2739Tue, 02 Feb 2021 15:11:19 +0000Collected Evidence: Collected Evidence: Use human observers onboard fishing vessels to monitor catches and discards We found no studies that evaluated the effects of using human observers onboard fishing vessels to monitor catches and discards 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%2F2740https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2740Tue, 02 Feb 2021 15:15:25 +0000Collected Evidence: Collected Evidence: Use citizen surveillance to report illegal fishing We found no studies that evaluated the effects of using citizen surveillance to report illegal fishing 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%2F2741https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2741Tue, 02 Feb 2021 15:37:26 +0000Collected Evidence: Collected Evidence: Enforce port controls We found no studies that evaluated the effects of enforcing port controls 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%2F2766https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2766Wed, 03 Feb 2021 10:03:11 +0000Collected Evidence: Collected Evidence: Use onboard CCTV for monitoring catches and discards We found no studies that evaluated the effects of using onboard CCTV monitoring 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%2F2767https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2767Wed, 03 Feb 2021 10:05:44 +0000Collected Evidence: Collected Evidence: Use flags to signal the legal nationality of a fishing vessel We found no studies that evaluated the effects of using a flag to identify the legal nationality of a fishing vessel 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%2F2768https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2768Wed, 03 Feb 2021 10:10:41 +0000Collected Evidence: Collected Evidence: Eliminate flags of convenience We found no studies that evaluated the effects of eliminating flags of convenience 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%2F2769https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2769Wed, 03 Feb 2021 10:27:16 +0000Collected Evidence: Collected Evidence: Establish open and transparent reporting of fishing effort data We found no studies that evaluated the effects of establishing open and transparent fishing effort data 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%2F2770https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2770Wed, 03 Feb 2021 10:37:50 +0000Collected Evidence: Collected Evidence: Use methods to trace the source of catch We found no studies that evaluated the effects of using methods to trace the sources of catches 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%2F2771https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2771Wed, 03 Feb 2021 11:18:06 +0000Collected Evidence: Collected Evidence: Issue high fines and penalties for non-compliance with fisheries regulations We found no studies that evaluated the effects of issuing high fines and penalties for non-compliance with fisheries regulations 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%2F2772https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2772Wed, 03 Feb 2021 11:19:38 +0000Collected Evidence: Collected Evidence: License fish buyers We found no studies that evaluated the effects of licensing fish buyers 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%2F2773https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2773Wed, 03 Feb 2021 11:25:34 +0000Collected Evidence: Collected Evidence: Include fishers in management groups for marine protected areas We found no studies that evaluated the effects of including fishers in management fora for marine protected areas 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%2F2809https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2809Fri, 05 Feb 2021 10:00:36 +0000Collected Evidence: Collected Evidence: Involve fishers in designing and trialling new gear types to encourage uptake of more selective fishing gear We found no studies that evaluated the effects of involving fishers in designing and trialling new gear types 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%2F2810https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2810Fri, 05 Feb 2021 10:02:04 +0000Collected Evidence: Collected Evidence: Introduce economic incentives to encourage sustainable fishing We found no studies that evaluated the effects of introducing economic incentives to encourage sustainable fishing 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%2F2811https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2811Fri, 05 Feb 2021 10:03:40 +0000Collected Evidence: Collected Evidence: Involve stakeholders in allocation of harvest rights We found no studies that evaluated the effects of involving stakeholders in the allocation of harvest rights 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%2F2812https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2812Fri, 05 Feb 2021 10:07:06 +0000Collected Evidence: Collected Evidence: Engage stakeholders/fishers in scientific research and data collection We found no studies that evaluated the effects of engaging fishers in scientific data collection 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%2F2813https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2813Fri, 05 Feb 2021 10:08:31 +0000Collected Evidence: Collected Evidence: Promote knowledge exchange between fishers to improve good practice We found no studies that evaluated the effects of promoting knowledge exchange between fishers to improve good practice 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%2F2814https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2814Fri, 05 Feb 2021 10:10:50 +0000Collected Evidence: Collected Evidence: Involve fishers and stakeholders in co-management Three studies examined the effect of involving fishers and stakeholders in co-management on marine fish populations. One study was in each of the Indian Ocean, the South China Sea (Vietnam) and the Pacific Ocean (Tonga).  COMMUNITY RESPONSE (1 STUDIES) POPULATION RESPONSE (1 STUDY) Abundance (1 study): One before-and-after study the Indian Ocean found that involving fishers and stakeholders in co-management increased overall fish abundance, but abundance varied between species groups, nine years after implementation compared to before. BEHAVIOUR (0 STUDIES) OTHER (2 STUDIES) Reduction of fishing effort (1 study): One before-and-after study in the Pacific Ocean found that in the five years after implementation of a new co-management system there was no decrease in overall fishing effort in the managed area. Commercial catch abundance (1 study): One before-and-after study in the Pacific Ocean found no increase in total fish catch rates and a decrease in catch rates of half of the six species groups individually inside an area with a new co-management system after five years. Improved compliance/reduction of illegal fishing activity (1 study): One before-and-after study in the South China Sea reported that after co-management was established in an area there was a decrease in illegal fishing using destructive fishing gears. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2910https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2910Mon, 08 Feb 2021 16:20:11 +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