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Hastie GD, Lepper P, McKnight JC, Milne R, Russell DJF, Thompson D. Acoustic risk balancing by marine mammals: anthropogenic noise can influence the foraging decisions by seals. J Appl Ecol 2021. [DOI: 10.1111/1365-2664.13931] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Gordon D. Hastie
- Sea Mammal Research Unit Scottish Oceans Institute University of St Andrews St Andrews Fife UK
| | | | - J. Chris McKnight
- Sea Mammal Research Unit Scottish Oceans Institute University of St Andrews St Andrews Fife UK
| | - Ryan Milne
- Sea Mammal Research Unit Scottish Oceans Institute University of St Andrews St Andrews Fife UK
| | - Debbie J. F. Russell
- Sea Mammal Research Unit Scottish Oceans Institute University of St Andrews St Andrews Fife UK
| | - David Thompson
- Sea Mammal Research Unit Scottish Oceans Institute University of St Andrews St Andrews Fife UK
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Detection of Visual Signatures of Marine Mammals and Fish within Marine Renewable Energy Farms using Multibeam Imaging Sonar. JOURNAL OF MARINE SCIENCE AND ENGINEERING 2019. [DOI: 10.3390/jmse7020022] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Techniques for marine monitoring have been greatly evolved over the past decades, making the acquisition of environmental data safer, more reliable and more efficient. On the other hand, the marine renewable energy sector has introduced dissimilar ways of exploring the oceans. Marine energy is mostly harvested in murky and high energetic places where conventional data acquisition techniques are impractical. This new frontier on marine operations brings the need for finding new techniques for environmental data acquisition, processing and analysis. Modern sonar systems, operating at high frequencies, can acquire detailed images of the underwater environment. Variables such as occurrence, size, class and behavior of a variety of aquatic species of fish, birds, and mammals that coexist within marine energy sites can be monitored using imaging sonar systems. Although sonar images can provide high levels of detail, in most of the cases they are still difficult to decipher. In order to facilitate the classification of targets using sonar images, this study introduces a framework of extracting visual features of marine animals that would serve as unique signatures. The acoustic visibility measure (AVM) is here introduced as technique of identification and classification of targets by comparing the observed size with a standard value. This information can be used to instruct algorithms and protocols in order to automate the identification and classification of underwater targets using imaging sonar systems. Using image processing algorithms embedded in Proviwer4 and FIJI software, this study found that acoustic images can be effectively used to classify cod, harbour and grey seals, and orcas through their size, shape and swimming behavior. The sonar images showed that cod occurred as bright, 0.9 m long, ellipsoidal targets shoaling in groups. Harbour seals occurred as bright torpedo-like fast moving targets, whereas grey seals occurred as bulky-ellipsoidal targets with serpentine movements. Orca or larger marine mammals occurred with relatively low visibility on the acoustic images compared to their body size, which measured between 4 m and 7 m. This framework provide a new window of performing qualitative and quantitative observations of underwater targets, and with further improvements, this method can be useful for environmental studies within marine renewable energy farms and for other purposes.
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Verfuss UK, Gillespie D, Gordon J, Marques TA, Miller B, Plunkett R, Theriault JA, Tollit DJ, Zitterbart DP, Hubert P, Thomas L. Comparing methods suitable for monitoring marine mammals in low visibility conditions during seismic surveys. MARINE POLLUTION BULLETIN 2018; 126:1-18. [PMID: 29421075 DOI: 10.1016/j.marpolbul.2017.10.034] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 10/06/2017] [Accepted: 10/16/2017] [Indexed: 06/08/2023]
Abstract
Loud sound emitted during offshore industrial activities can impact marine mammals. Regulations typically prescribe marine mammal monitoring before and/or during these activities to implement mitigation measures that minimise potential acoustic impacts. Using seismic surveys under low visibility conditions as a case study, we review which monitoring methods are suitable and compare their relative strengths and weaknesses. Passive acoustic monitoring has been implemented as either a complementary or alternative method to visual monitoring in low visibility conditions. Other methods such as RADAR, active sonar and thermal infrared have also been tested, but are rarely recommended by regulatory bodies. The efficiency of the monitoring method(s) will depend on the animal behaviour and environmental conditions, however, using a combination of complementary systems generally improves the overall detection performance. We recommend that the performance of monitoring systems, over a range of conditions, is explored in a modelling framework for a variety of species.
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Affiliation(s)
- Ursula K Verfuss
- SMRU Consulting, Europe, New Technology Centre, North Haugh, St Andrews, Fife KY16 9SR, UK.
| | - Douglas Gillespie
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, Fife KY16 8LB, UK
| | - Jonathan Gordon
- Marine Ecological Research, 7 Beechwood Terrace West, Newport-On-Tay, Fife DD6 8JH, UK
| | - Tiago A Marques
- Centre for Research into Ecological and Environmental Modelling, The Observatory, University of St Andrews, St Andrews, Fife KY16 9LZ, UK
| | - Brianne Miller
- SMRU Consulting, North America, 1529 W 6th Ave, Vancouver, BC V6J 1R1, Canada
| | - Rachael Plunkett
- SMRU Consulting, Europe, New Technology Centre, North Haugh, St Andrews, Fife KY16 9SR, UK
| | - James A Theriault
- Ocean Environmental Consulting, 9 Ravine Park Cres, Halifax B3M 4S6, NS, Canada
| | - Dominic J Tollit
- SMRU Consulting, North America, 1529 W 6th Ave, Vancouver, BC V6J 1R1, Canada
| | - Daniel P Zitterbart
- Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany
| | - Philippe Hubert
- Prove Systems Ltd, Unit 1 Mill court, Mill lane, Tayport, Fife DD6 9EL, UK
| | - Len Thomas
- Centre for Research into Ecological and Environmental Modelling, The Observatory, University of St Andrews, St Andrews, Fife KY16 9LZ, UK
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Reichmuth C, Ghoul A, Sills JM, Rouse A, Southall BL. Low-frequency temporary threshold shift not observed in spotted or ringed seals exposed to single air gun impulses. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2016; 140:2646. [PMID: 27794299 DOI: 10.1121/1.4964470] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Underwater hearing thresholds were measured at 100 Hz in trained spotted (Phoca largha) and ringed seals (Pusa hispida) before and immediately following voluntary exposure to impulsive noise from a seismic air gun. Auditory responses were determined from psychoacoustic data and behavioral responses were scored from video recordings. Four successive exposure conditions of increasing level were tested, with received unweighted sound exposure levels from 165 to 181 dB re 1 μPa2 s and peak-to-peak sound pressures from 190 to 207 dB re 1 μPa. There was no evidence that these single seismic exposures altered hearing-including in the highest exposure condition, which matched previous predictions of temporary threshold shift (TTS) onset. Following training at low exposure levels, relatively mild behavioral responses were observed for higher exposure levels. This demonstrates that individuals can learn to tolerate loud, impulsive sounds, but does not necessarily imply that similar sounds would not elicit stronger behavioral responses in wild seals. The absence of observed TTS confirms that regulatory guidelines (based on M-weighting) for single impulse noise exposures are conservative for seals. However, additional studies using multiple impulses and/or higher exposure levels are needed to quantify exposure conditions that do produce measurable changes in hearing sensitivity.
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Affiliation(s)
- Colleen Reichmuth
- Institute of Marine Sciences, Long Marine Laboratory, University of California-Santa Cruz, Santa Cruz, California 95060, USA
| | - Asila Ghoul
- Institute of Marine Sciences, Long Marine Laboratory, University of California-Santa Cruz, Santa Cruz, California 95060, USA
| | - Jillian M Sills
- Institute of Marine Sciences, Long Marine Laboratory, University of California-Santa Cruz, Santa Cruz, California 95060, USA
| | - Andrew Rouse
- Southall Environmental Associates (SEA), Incorporated, 9099 Soquel Drive, Suite 8, Aptos, California 95003, USA
| | - Brandon L Southall
- Southall Environmental Associates (SEA), Incorporated, 9099 Soquel Drive, Suite 8, Aptos, California 95003, USA
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