Reactions of harbour porpoise (Phocoena phocoena) to vessel traffic in the coastal waters of South West Wales, UK

Oakley, Judith A.; Williams, A. T.; Thomas, Tony

doi:10.1016/j.ocecoaman.2017.01.003

Cited by 20 publications

(24 citation statements)

References 29 publications

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“…4). Similar dominance of noise from recreational vessels has been reported in other studies of vessel presence in coastal areas 25,42 . We acknowledge that this ratio is highly habitat-specific, but argue that many shallow, coastal habitats with protected marine life will have comparable ratios of recreational to commercial vessels.…”

Section: Discussionsupporting

confidence: 87%

“…5; see also Supplementary Table S3), which is also supported by previous studies relating higher speeds with increased propeller cavitation noise 15,47 . High vessel speeds have been associated with more pronounced reactions in toothed whales 25,27,42,48 . Oakley et al .…”

Section: Discussionmentioning

confidence: 99%

“…Oakley et al . 42 found that 75% of negative reactions in harbour porpoises were caused by high-speed vessels. This is, however, not only due to higher levels of vessel noise associated with high speeds, but likely also because high speeds cause faster rise times of received noise levels.…”

Section: Discussionmentioning

confidence: 99%

“…Harbour porpoises require strict protection and maintenance of their breeding and resting areas 38,39 and they inhabit shallow, coastal water habitats 36,37 . A number of studies have investigated responses of porpoises to vessel noise and found significant behavioural alterations 35,41,42 . To estimate the potential effects of vessel noise, we applied response thresholds from three published studies to our recordings to identify noise events that could be expected to elicit behavioural responses in porpoises (see Supplementary Material for further details and a description of how these thresholds were applied to the data).…”

Section: Methodsmentioning

confidence: 99%

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Recreational vessels without Automatic Identification System (AIS) dominate anthropogenic noise contributions to a shallow water soundscape

Hermannsen

Mikkelsen

Tougaard

et al. 2019

Sci Rep

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Recreational boating is an increasing activity in coastal areas and its spatiotemporal overlap with key habitats of marine species pose a risk for negative noise impacts. Yet, recreational vessels are currently unaccounted for in vessel noise models using Automatic Identification System (AIS) data. Here we conduct a case study investigating noise contributions from vessels with and without AIS (non-AIS) in a shallow coastal area within the Inner Danish waters. By tracking vessels with theodolite and AIS, while recording ambient noise levels, we find that non-AIS vessels have a higher occurrence (83%) than AIS vessels, and that motorised recreational vessels can elevate third-octave band noise centred at 0.125, 2 and 16 kHz by 47–51 dB. Accordingly, these vessels dominated the soundscape in the study site due to their high numbers, high speeds and proximity to the coast. Furthermore, recreational vessels caused 49–85% of noise events potentially eliciting behavioural responses in harbour porpoises (AIS vessels caused 5–24%). We therefore conclude that AIS data would poorly predict vessel noise pollution and its impacts in this and other similar marine environments. We suggest to improve vessel noise models and impact assessments by requiring that faster and more powerful recreational vessels carry AIS-transmitters.

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Section: Discussionsupporting

confidence: 87%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Recreational vessels without Automatic Identification System (AIS) dominate anthropogenic noise contributions to a shallow water soundscape

Hermannsen

Mikkelsen

Tougaard

et al. 2019

Sci Rep

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“…There are considerably fewer studies regarding behavioural responses of other species, such as harbour porpoises (Phocoena phocoena), to specific boat types. Baş et al (2017a) demonstrated the effect of general marine traffic presence on the behavioural budget of harbour porpoises in the Istanbul Strait, revealing a significant increase in porpoises' avoidance behaviours in the presence of marine traffic, whilst Oakley et al (2017) reported that harbour porpoise behaviour is hardly affected by boat type.…”

Section: Introductionmentioning

confidence: 99%

Behavioural changes and potential consequences of cetacean exposure to purse seine vessels in the Istanbul Strait, Turkey

Meza¹,

Akkaya²,

Affinito³

et al. 2020

J. Mar. Biol. Ass.

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Marine traffic has both short- and long-term effects on cetacean behaviour, yet fishing vessels present a unique situation as they disturb cetaceans whilst potentially offering alternative foraging opportunities. The Istanbul Strait is a key area for the study of anthropogenic disturbance on cetaceans due to heavy human pressure in a narrow space where at least three cetacean species are regularly encountered. The present study investigated changes in behaviour of bottlenose dolphins, common dolphins and harbour porpoises in relation to the presence of purse seiners using Markov chains analysis. The results revealed increased foraging in bottlenose and common dolphins' behavioural budgets and a decrease in the time spent foraging by harbour porpoises. Moreover, a loglinear model was used to analyse the effect of possible confounding variables on observed behaviours. The only variables found to be affecting behaviour were the previous recorded behaviour, seiner presence and marine traffic density. Consequently, the presence of purse seine vessels leads bottlenose and common dolphins to change their behaviour and are related with a decrease of energy intake in porpoises. The results of this study reveal that there is an effect of purse seine vessel presence on the cetaceans found in the Istanbul Strait with potentially significant impacts on their behaviour, therefore we suggest more research is needed in the area to identify the long-term impacts of these observed behavioural changes.

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Harbour porpoises respond to recreational boats by speeding up and moving away from the boat path

Hao,

Hamel,

Grandjean

et al. 2024

Ecology and Evolution

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Recreational boats are common in many coastal waters, yet their effects on cetaceans and other sensitive marine species remain poorly understood. To address this knowledge gap, we used drone video footage recorded from a recreational boat to quantify how harbour porpoises (Phocoena phocoena) responded to the boat approaching at different speeds (10 or 20 knots). Furthermore, we used a hydrophone to record boat noise levels at full bandwidth (0.1–150 kHz) and at the 1/3 octave 16 kHz frequency band for both experimental speeds. The experiments were carried out in shallow waters near Funen, Denmark (55.51° N, 10.79° E) between July and September 2022. Porpoises were more likely to move further away from the path of the boat when approached at 10 knots, but not when approached at 20 knots. In contrast, they swam faster when approached at 20 knots, but not when approached at 10 knots. The recorded received sound level did not depend on how fast the boat approached, suggesting that differences in porpoise responses were related to the speed of the approaching boat rather than to sound intensity. In addition, porpoises generally reacted within close proximity (<200 m) to the approaching boat and quickly (<50 s) resumed their natural behaviour once the boat had passed, indicating that the direct impact of small vessels on porpoise behaviour was most likely small. Nevertheless, repeated exposure to noise from small vessels may influence porpoises' activity or energy budget, and cause them to relocate from disturbed areas. The approach used in this study increases our understanding of recreational boats' impact on harbour porpoises and can be used to inform efficient mitigation measures to help focus conservation efforts.

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Reactions of harbour porpoise (Phocoena phocoena) to vessel traffic in the coastal waters of South West Wales, UK

Cited by 20 publications

References 29 publications

Recreational vessels without Automatic Identification System (AIS) dominate anthropogenic noise contributions to a shallow water soundscape

Recreational vessels without Automatic Identification System (AIS) dominate anthropogenic noise contributions to a shallow water soundscape

Behavioural changes and potential consequences of cetacean exposure to purse seine vessels in the Istanbul Strait, Turkey

Harbour porpoises respond to recreational boats by speeding up and moving away from the boat path

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