Study

Response of humpback whales (Megaptera novaeangliae) to ramp-up of a small experimental air gun array

  • Published source details Dunlop R.A., Noad M.J., McCauley R.D., Kniest E., Slade R., Paton D. & Cato D.H. (2016) Response of humpback whales (Megaptera novaeangliae) to ramp-up of a small experimental air gun array. Marine Pollution Bulletin, 103, 72-83

Actions

This study is summarised as evidence for the following.

Action Category

Use ‘soft start’ procedures to deter marine and freshwater mammals to reduce noise exposure

Action Link
Marine and Freshwater Mammal Conservation
  1. Use ‘soft start’ procedures to deter marine and freshwater mammals to reduce noise exposure

    A study in 2011 of a pelagic area in the South Pacific Ocean off the east coast of Australia (Dunlop et al. 2016) found that during ‘soft start’ procedures using seismic airguns, migrating humpback whale Megaptera novaeangliae groups slowed their speed but did not significantly alter their course. Overall, migrating humpback whale groups swam more slowly as they approached a vessel during ‘soft start’ procedures compared to before ‘soft starts’ (data reported as statistical model results). However, whale groups did not significantly alter their course during ‘soft starts’. The authors reported a similar response by whale groups to vessels without airguns firing (see original paper for details). During each of 22 trials, a ‘soft start’ procedure was carried out by a 28-m vessel towing a small experimental airgun array (six 20–150 cubic inch air guns) at a speed of 7.4 km/h across a humpback whale migration path. Airguns were progressively activated (at 2,000 psi) during four stages, in which the sound exposure level was increased in steps of 6 dB. Migrating whale groups (1–3 whales) were tracked with a theodolite from two land-based stations and observed from three small research vessels for 1-h before and 30-minutes during the ‘soft start’ procedure during each of the 22 trials in September–October 2011.

    (Summarised by: Anna Berthinussen)

Output references

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, terrestrial 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 18

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