Study

The effectiveness of a seal scarer at a wild salmon net fishery

  • Published source details Harris R.N., Harris C.M., Duck C.D. & Boyd I.L. (2014) The effectiveness of a seal scarer at a wild salmon net fishery. ICES Journal of Marine Science, 71, 1913-1920.

Actions

This study is summarised as evidence for the following.

Action Category

Use acoustic devices on fishing gear

Action Link
Marine and Freshwater Mammal Conservation
  1. Use acoustic devices on fishing gear

    A randomized, controlled study in 2009–2010 at a coastal site (water body not stated) in Scotland, UK (Harris et al. 2014) found that using an acoustic device at a bag-net reduced the number of grey seals Halichoerus grypus and harbour seals Phoca vitulina around the net and the amount of seal-damaged salmon (Salmonidae). The number of grey and harbour seal sightings/survey within 80 m of the net was lower when the acoustic device was active than when it was inactive (data reported as statistical model results). No seal-damaged salmon were found in the nets when the acoustic device was turned on, whereas 5–7% of salmon catches were damaged when the device was off. An acoustic device (Lofitech Seal Scarer) was deployed alongside a salmon double bag-net deployed 90 m offshore. In July–August 2009 and 2010, the acoustic device was randomly set as active (emitting 500 ms pulses at 15 kHz) or inactive (silent) for 12 h (2009) or 24 h periods (2010). An observer recorded seals from the shore during surveys (each lasting an average of 1.4 h) with the device turned on (34 surveys) and off (41 surveys). Fishers recorded seal-damaged catches during hauls with the device turned on (78 hauls) and off (104 hauls).

    (Summarised by: Anna Berthinussen)

Output references
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 19

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 Programme Red List Champion - Arc Kent Wildlife Trust The Rufford Foundation Save the Frogs - Ghana Bern wood Supporting Conservation Leaders National Biodiversity Network Sustainability Dashboard Frog Life The international journey of Conservation - Oryx British trust for ornithology Cool Farm Alliance UNEP AWFA Butterfly Conservation People trust for endangered species Vincet Wildlife Trust