Habituation to an acoustic harassment device (AHD) by killer whales depredating demersal longlines

Open Access Peer Reviewed Publication 2015

ICES Journal of Marine Science

Acoustic harassment devices (AHDs) have been increasingly implemented in various fisheries that suffer significant losses caused by odontocete depredation. However, the efficacy of AHDs to deter odontocetes from fishing gear remains poorly investigated. To determine the effectiveness of AHDs in deterring depredation, we experimentally tested a high amplitude device (195 dB re 1 μPa 6.5 kHz 1 m from the source) from a Patagonian toothfish Dissostichus elegenoides longliner operating off the Crozet Islands, while it was subjected to heavy depredation by killer whales Orcinus orca. This species usually depredates longlines within a 10- to 300-m range from the vessel, as they only have access to fishing gear during hauling. We expected this distance to increase in response to the acoustic disturbance created by the AHD. The distances of 29 killer whales from the vessel (n = 1812 records) were collected during phases of AHD activation and phases during which the AHD was turned off. Two multiexposed killer whale social units fled over 700 m away from the vessel when first exposed to the AHD. However, they remained within a 10- to 300-m range and depredated longlines again past the third and seventh exposures, respectively, showing an insignificant behavioural response to further activations of the AHD. When tested through generalized linear mixed models, the effect of AHD activation was only significant when killer whales were first exposed to the device. However, the effect disappeared after successive exposures suggesting that killer whales became habituated to the AHD and may sustain potentially harmful hearing disturbance to access the resource made available by longliners. In addition to raising significant conservation concerns, this rapid return of initial depredation behaviour strongly suggests that AHDs are ineffective at deterring depredating killer whales, and that fisheries should favour the use of other mitigation techniques when facing repeated depredation by this species.

Link To Publication

Similar Research

Anthropogenic sound and marine mammal health: measures of the nervous and immune systems before and after intense sound exposure

Pay-walled Journal Article 2004

Canadian Journal of Fisheries and Aquatic Sciences

Anthropogenic sound is a potential stressor for marine mammals that may affect health, as has been demonstrated in other mammals. Therefore, we have initiated investigations on...
Read More

Response and Responsibility: Regulating Noise Pollution in the Marine Environment

Pay-walled Journal Article 2007

Journal of International Wildlife Law and Policy

The ocean is becoming an increasingly noisy environment. With a rise in com-mercial shipping, resource extraction activities, and military-related activities,the underwater ocean environment is a virtual...
Read More

Influences of man-made noise and other human actions on cetacean behaviour

Pay-walled Journal Article 1995

Marine and Freshwater Behaviour and Physiology

Behavioral reactions of cetaceans to man-made noises are highly variable, ranging from attraction (e.g. bow riding by dolphins) or no response through short-term changes in behaviour...
Read More

International Regulation Of Transboundary Pollutants: The Emerging Challenge Of Ocean Noise

Open Access Journal Article 2001

Ocena and Coastal Law Journal

Transboundary pollution law poses the challenge of addressing environmental problems irrespective of boundaries in an international legal system that values, above all, territorial sovereignty of individual...
Read More

A Brief Review of Anthropogenic Sound in the Oceans

Open Access Journal Article 2007

International Journal of Comparative Psychology

Sound in the oceans is generated by a variety of natural sources, such as breaking waves, rain, and marine animals, as well as a variety of...
Read More

Effect of anthropogenic low-frequency noise on the foraging ecology of Balaenoptera whales

Pay-walled Journal Article 2006

Animal Conservation

The human contribution to ambient noise in the ocean has increased over the past 50 years, and is dominated by low-frequency (LF) sound (frequencies <1000 Hz)...
Read More

Determination of environmental sensitivity of acoustic propagation on continental shelves using an equivalent fluid parabolic equation model

Pay-walled Journal Article 1995

The Journal of the Acoustical Society of America

A coupled environment and acoustic prediction system was developed to evaluate the sensitivity of acoustic propagation on the continental shelf to water column and sediment properties....
Read More

Effects of underwater noise on auditory sensitivity of a cyprinid fish

Pay-walled Journal Article 2001

Hearing Research

The ability of a fish to interpret acoustic information in its environment is crucial for its survival. Thus, it is important to understand how underwater noise...
Read More

Effects of noise exposure on click detection and the temporal resolution ability of the goldfish auditory system

Pay-walled Journal Article 2005

Hearing Research

Hearing specialist fishes investigated so far revealed excellent temporal resolution abilities, enabling them to accurately process temporal patterns of sounds. Because noise is a growing environmental...
Read More

The effects of noise on the auditory sensitivity of the bluegill sunfish, Lepomis macrochirus

Pay-walled Journal Article 2002

Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology

As concerns about the effects of underwater anthropogenic noises on the auditory function of organisms increases, it is imperative to assess if all organisms are equally...
Read More