Exploring Passive Acoustics in Fisheries

Photo credit: National Oceanic and Atmospheric Administration/Department of Commerce

Because of their non-invasive nature, passive acoustic technologies hold special promise in helping to resolve many of our current fisheries issues. Over 800 species of fishes worldwide are known to be vocal, including some of the most abundant and commercial fish species. Passive acoustics offers a unique tool to study these fishes, which often live in dark and turbid waters and are difficult to observe by other means. Passive acoustic techniques can be used to locate concentrations of particular species, especially during their vulnerable spawning stage. This in turn allows spawning habitat to be identified, mapped, and protected, so that numbers of fish can be assessed.

Passive acoustics can also be used to gain a better understanding of fish behavior, including fish migrations. In addition, these techniques can be used to simultaneously monitor sources of noise pollution, and to study the impact of human activities on marine communities. Anthropogenic sources include noise generated by boating activity, seismic surveys, sonars, fish-finders, depth finders, drilling for oil and gas, and military activities. These all have an unknown but potential important impact on marine fauna.

NEW! The Sea Grant Digital Ocean's publication Listening to Fish: Passive Acoustic Applications in Marine Fisheries is now available here online in PDF format. (Adobe's Acrobat Reader software is needed to read it; the free shareware application can be downloaded from Adobe Systems at http://www.adobe.com/products/acrobat/readstep2.html).