Acoustic alarms reduce porpoise mortality

Kraus, Scott D.; Read, Andrew J.; Solow, Andrew R.; Baldwin, K. G. H.; Spradlin, Trevor R.; Anderson, Eric J.; Williamson, John

doi:10.1038/41451

Cited by 170 publications

(181 citation statements)

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“…Here we present the results of 2 field experiments which demonstrate that harbor porpoises avoid acoustic alarms, thereby becoming effectively excluded from ensonified areas, whereas herring Clupea harengus, one of their main prey species (Kraus et al 1997), are not affected.…”

Section: Introductionmentioning

confidence: 99%

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Reactions of harbor porpoises Phocoena phocoena and herring Clupea harengus to acoustic alarms

Culik¹,

Koschinski²,

Tregenza³

et al. 2001

Mar. Ecol. Prog. Ser.

114

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Small cetaceans are susceptible to incidental mortality in the various forms of gillnet fisheries throughout their range. Research conducted since 1994 has shown that acoustic alarms (pingers) emitting high-frequency pulsed sounds effectively reduce the number of harbor porpoise Phocoena phocoena casualties in sink gillnets. However, the mechanisms behind the effects of pingers were still not understood. Until now, advantages and risks associated with their widespread use could not be evaluated. Here we present the results of 2 field experiments: (1) theodolite-tracking of harbor porpoises exposed to a single PICE-pinger in Clayoquot Sound, Vancouver Island, Canada and (2) herring Clupea harengus capture rates in surface gillnets equipped with and without acoustic alarms (Dukane Netmark 1000, Lien, PICE) in the Baltic Sea herring fishery at Rügen Island, Germany. Our results show that harbor porpoises do not seem to react to an experimental net in their foraging area (n = 172 groups, median group size = 2 porpoises). Porpoise distance from the mid-point of the net was distributed around a median of only 150 m (range 4 to 987 m). A net equipped with an acoustic alarm, however, was avoided (n = 44 groups) within audible range (distance distribution median = 530 m, range 130 to 1140 m). The porpoises were thus effectively excluded from the ensonified area. Herring, one of the main prey species of harbor porpoises, were not affected by the acoustic alarms tested (n = 25 407 fish captured). The advantages and risks of using acoustic alarms to mitigate by-catch are discussed.KEY WORDS: Harbor porpoise · By-catch · Mortality · Theodolite-tracking · Acoustic alarms · Pinger · Gillnets · NoiseResale or republication not permitted without written consent of the publisher

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Section: Introductionmentioning

confidence: 99%

“…Research conducted since 1994 (Lien & Hood 1994) has shown that acoustic alarms emitting high-frequency pulsed sounds effectively reduce the number of harbor porpoise casualties in sink gillnets (Kraus et al 1997, Trippel et al 1999). This has led to their compulsory use in some fisheries (Trippel et al 1999, Finn Larsen pers.…”

Section: Introductionmentioning

confidence: 99%

Reactions of harbor porpoises Phocoena phocoena and herring Clupea harengus to acoustic alarms

Culik¹,

Koschinski²,

Tregenza³

et al. 2001

Mar. Ecol. Prog. Ser.

114

View full text Add to dashboard Cite

show abstract

“…Fishing nets, for example, equipped with high-frequency pingers (typically greater than 10 kHz) had reduced Atlantic herring catches in one study (Kraus et al 1997), but not in two others (Trippel et al 1999;Culik et al 2001). In another study, Pacific herring were shown to change their behaviour in response to simulated echolocation clicks (Wilson & Dill 2002).…”

Section: Introductionmentioning

confidence: 99%

Pacific herring hearing does not include ultrasound

2005

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Recent studies have shown that some clupeid fishes, including shad and menhaden, can detect ultrasound (sound with frequencies higher than 20 kHz) and actively avoid it. However, other clupeids, including sardines and anchovies, do not detect ultrasound. The hearing abilities of herring are of particular interest because of their commercial importance, our reliance on acoustics to monitor their populations and behavioural evidence of responses to high-frequency sound by some clupeid species. We measured the hearing sensitivity of Pacific herring (Clupea pallasii) using the auditory brainstem response and found that they were unable to detect ultrasonic signals at received levels up to 185 dB re 1 mPa. Herring had hearing thresholds at lower frequencies (100-5000 Hz) that were typical of other non-ultrasound-detecting clupeids. This lowerfrequency hearing sensitivity could explain the results of several earlier studies showing responses to broadband sounds.

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“…Although in many studies (Trippel et al, 1999;Gearin et al, 2000, Culik et al, 2001, Wilson and Dill, 2002, it is proved that pingers do not negatively effect the catch rate of target species, Kraus et al (Kraus et al, 1997), asserted that pingers cause reduction in target catch rate in a study performed on Atlantic herring ( Clupea harengus ).…”

Section: Reduction Of Catch Ratementioning

confidence: 99%

Technical Measures in Order to Decrease Interactions Between Dolphins and Fishermen: Pingers

Gönener¹,

Özsandıkçı²

2017

J Aquacult Eng Fish Res

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Abstract:Almost all marine mammal species are in interaction with fishing activities and this interaction frequently results with the death of marine mammals in gillnet fisheries. This situation which results with the death of thousands of harbor porpoise (Phocoena phocoena) and bottlenose dolphin (Tursiops truncatus) is defined as by-catch ( non-target catch) in gillnet fisheries and in this way it is legalized at least partially. These inreactions between fisheries and dolphins cause ecologic and social concerns, while that means much more economic losses from the perspective of fishermen. In most of studies which aim to determine necessary measures to reduce by-catch of dolphins, gillnet fisheries is taken as basis and dolphin deterrent devices called pingers are used. In this subject many studies have been carried out in world, while only a few in Black Sea. However, it is still difficult to make an assessment for effectiveness of pingers. In addition to this, many studies including those of performed in Black Sea outline that pingers can keep harbor porpoise (Phocoena phocoena) and bottlenose dolphin (Tursiops truncatus) away from gillnets for 1-2 years but it is vital that monitoring the situation after this period.

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Acoustic alarms reduce porpoise mortality

Cited by 170 publications

References 1 publication

Reactions of harbor porpoises Phocoena phocoena and herring Clupea harengus to acoustic alarms

Reactions of harbor porpoises Phocoena phocoena and herring Clupea harengus to acoustic alarms

Pacific herring hearing does not include ultrasound

Technical Measures in Order to Decrease Interactions Between Dolphins and Fishermen: Pingers

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