Article
Acoustics
Jakob Tougaard, Kristian Beedholm, Peter T. Madsen
Summary: This article reviews the evidence available after 2015 regarding the criteria for noise-induced hearing loss in marine mammals. It analyzes the thresholds for impulsive sounds and non-impulsive sounds in two functional hearing groups. The current thresholds have strong support for certain cetaceans and seals, but discrepancies exist in other frequency ranges, calling for further studies.
JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA
(2022)
Article
Fisheries
Dennis Brennecke, Ursula Siebert, Lotte Kindt-Larsen, Henrik Skov Midtiby, Henrik Dyrberg Egemose, Sara Torres Ortiz, Katrin Knickmeier, Magnus Wahlberg
Summary: This study demonstrates that harbor porpoises exhibit strong avoidance behavior and reduced surfacing frequency in response to pinger sounds, indicating the effectiveness of pingers in reducing bycatch. However, there is also a diversity in behavioral responses, with some porpoises not reacting to pinger sounds at all. This suggests that pinger use should be carefully considered and alternative mitigation measures may need to be explored.
FISHERIES RESEARCH
(2022)
Article
Acoustics
Ronald A. Kastelein, Lean Helder-Hoek, Jennifer Covi, John M. Terhune, Georg Klump
Summary: Acoustic masking reduces communication efficiency, prey detection, and predator avoidance in marine mammals. This study examined harbor porpoises' ability to detect sounds in amplitude-varying masking noise. Results show that SAM rate has a significant impact on masking release, while signal duration, masker bandwidth, and modulation depth have less effect.
JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA
(2021)
Article
Environmental Sciences
Alexandre N. N. Zerbini, Kimberly T. T. Goetz, Karin A. A. Forney, Charlotte Boyd
Summary: This study used distance sampling to estimate the abundance of harbor porpoises in the Southeast Alaska inland waters, and found that bycatch in the drift gillnet fishery may be unsustainable for the southern population. Monitoring the abundance and bycatch is therefore important for evaluating the potential impact of fisheries on this species in Southeast Alaska.
FRONTIERS IN MARINE SCIENCE
(2022)
Article
Marine & Freshwater Biology
Duncan J. Irschick, Johnson Martin, Ursula Siebert, Jakob H. Kristensen, Peter T. Madsen, Fredrik Christiansen
Summary: This study demonstrates the use of photography and video to create accurate 3D models of harbor porpoises, which can be valuable for body condition assessment, computational fluid dynamics models of locomotion, and education. The authors used a combination of still photographs, drone video, and synchronized GoPro videos to recreate the 3D body meshes, confirming their accuracy through comparison with original measures taken on the specimens. Additionally, an animated version of a live harbor porpoise was provided for educational purposes.
MARINE MAMMAL SCIENCE
(2021)
Article
Environmental Sciences
Julika Voss, Armin Rose, Vladislav Kosarev, Raul Vilela, Ilse Catharina van Opzeeland, Ansgar Diederichs
Summary: Before piling, acoustic harassment devices (AHDs) are used to drive harbor porpoises away from the area. The use of seal scarers led to unintended decreased porpoise detection rates beyond the intended distances, causing the development of new devices specifically designed for mitigation purposes. The present study monitored harbor porpoise detection rates during piling using these new devices and found a significant decrease in detection rates near the devices, indicating the displacement of the animals from a small-scale area.
FRONTIERS IN MARINE SCIENCE
(2023)
Article
Pathology
Lonneke L. IJsseldijk, Meike Scheidat, Marije L. Siemensma, Bram Couperus, Mardik F. Leopold, Maria Morell, Andrea Grone, Marja J. L. Kik
Summary: Bycatch is a significant threat to cetaceans worldwide, with bottom-set gillnets posing a specific risk to harbor porpoises. Methods to assess bycatch rates include on-board observers, electronic monitoring, and fishermen reporting, but systematic approaches are lacking. Necropsies of stranded animals provide insights into bycatch occurrence and health status, but uncertainties remain due to the absence of specific diagnostic tools for underwater entrapment.
VETERINARY PATHOLOGY
(2021)
Article
Multidisciplinary Sciences
Siri L. Elmegaard, Jonas Teilmann, Laia Rojano-Donate, Dennis Brennecke, Lonnie Mikkelsen, Jeppe D. Balle, Ulrich Gosewinkel, Line A. Kyhn, Pernille Tonnesen, Magnus Wahlberg, Andreas Ruser, Ursula Siebert, Peter Teglberg Madsen
Summary: This study investigates the physiological and behavioral responses of harbor porpoises to a commercial acoustic harassment device (AHD). The results show that AHD exposure can trigger startled responses, flight responses, and cardiac responses in porpoises, potentially impacting their blood-gas management, breath-hold capability, energy balance, stress levels, and risk of by-catch.
SCIENTIFIC REPORTS
(2023)
Article
Oceanography
Xiuqing Hao, Jacob Nabe-Nielsen
Summary: Danish coastal waters, known for recreational boating and harbour porpoises, lack data on boat speeds and distributions, making it difficult to assess the impact of boat noise on the porpoises. Researchers used coastal observations and satellite images to determine the relationship between boat speed and size/type and the spatial distribution of small boats. Results showed that boat speed varied among marinas and motorboats were the dominant type, with the probability of observing boats decreasing with distance from the shore. This study highlights the importance of combining observation and satellite data in assessing the impact of boats on wildlife.
OCEAN & COASTAL MANAGEMENT
(2023)
Article
Acoustics
Likun Zhao, Giacomo Giorli, Francesco Caruso, Lijun Dong, Zining Gong, Mingli Lin, Songhai Li
Summary: This study describes the characteristics of echolocation clicks of Indo-Pacific finless porpoises in the Hainan waters, China, and examines their adaptation to the sonar system in the area. A total of 65 on-axis clicks were recorded and analyzed, showing that these porpoises produce clicks with moderate source level and high peak frequency. These findings have implications for detecting and estimating the density of Indo-Pacific finless porpoises in the study area, as well as understanding the interpopulation variation in click characteristics of finless porpoises.
JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA
(2023)
Article
Engineering, Marine
Shaowei Wu, Yang Xiang, Tao Qin
Summary: A hybrid superposition method is developed for predicting seismic wave in elastic seabed excited by low frequency noise from ship submerged in shallow sea. The key feature of this method is that truncating and discretizing the field space are not required for the prediction, which reduces the original problem by one dimension, while accurate results are achieved.
Article
Evolutionary Biology
Yacine Ben Chehida, Roisin Loughnane, Julie Thumloup, Kristin Kaschner, Cristina Garilao, Patricia E. Rosel, Michael C. Fontaine
Summary: This study investigated the population structure and phylogeographic history of harbor porpoises in the North Atlantic using phylogenetics, population genetics, and predictive habitat modeling. The results revealed important departures from random mating and restricted dispersal, forming a highly significant isolation by distance. The findings provide insights into the processes shaping porpoise population structure and offer a framework for designing conservation strategies and forecasting future population evolution.
EVOLUTIONARY APPLICATIONS
(2021)
Article
Acoustics
A. M. von Benda-Beckmann, D. R. Ketten, F. P. A. Lam, C. A. F. de Jong, R. A. J. Mueller, R. A. Kastelein
Summary: The application of a kurtosis correction improved predictions of hearing damage risk for humans and terrestrial mammals exposed to different degrees of impulsiveness. However, its effectiveness in predicting marine mammal responses was limited.
JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA
(2022)
Article
Environmental Sciences
Aude Benhemma-Le Gall, Isla M. Graham, Nathan D. Merchant, Paul M. Thompson
Summary: Research comparing harbor porpoise occurrence and foraging activity at two Scottish offshore windfarms during baseline periods and different construction phases revealed widespread behavioral responses to construction activities. This highlights the importance of assessing and managing all vessel activities at offshore windfarm sites to minimize the potential impacts of anthropogenic noise.
FRONTIERS IN MARINE SCIENCE
(2021)
Article
Marine & Freshwater Biology
Ronald A. Kastelein, Nancy Jennings, Leonie A. E. Huijser
Summary: Observations at an odontocete rehabilitation center in the Netherlands revealed instances of interspecific cooperative behavior, including mutually beneficial cooperation and altruism, initiated by white-beaked dolphins towards humans and harbor porpoises. These observations provide valuable insights into the motivation and fitness benefits of such behavior.
Article
Ecology
Mats Amundin, Julia Carlstrom, Len Thomas, Ida Carlen, Jonas Teilmann, Jakob Tougaard, Olli Loisa, Line A. Kyhn, Signe Sveegaard, M. Louise Burt, Iwona Pawliczka, Radomil Koza, Bartlomiej Arciszewski, Anders Galatius, Jussi Laaksonlaita, Jamie MacAuley, Andrew J. Wright, Anja Gallus, Michael Dahne, Alejandro Acevedo-Gutierrez, Harald Benke, Jens Koblitz, Nick Tregenza, Daniel Wennerberg, Katharina Brundiers, Monika Kosecka, Cinthia Tiberi Ljungqvist, Ivar Jussi, Martin Jabbusch, Sami Lyytinen, Aleksej Saskov, Penina Blankett
Summary: Knowing the abundance of a population is crucial for assessing its conservation status and developing effective conservation plans. This study estimated the abundance of the Baltic Proper harbour porpoise for the first time through passive acoustic monitoring and found that it is critically endangered. Immediate and efficient conservation actions through international cooperation are urgently needed.
ECOLOGY AND EVOLUTION
(2022)
Article
Marine & Freshwater Biology
Ronald A. Kastelein, Christ A. F. de Jong, Jakob Tougaard, Lean Helder-Hoek, Linde N. Defillet
Summary: The broadband underwater sounds produced during offshore pile driving have impacts on the auditory and behavioral responses of harbor porpoises. Research shows that harbor porpoises respond most strongly to the higher frequencies in piling sounds. Therefore, frequency weighting of the sound exposure level (SEL) is important for predicting behavioral responses. Mitigation measures should focus on reducing the high-frequency part of piling sounds to alleviate their effects on harbor porpoise behavior.
Article
Acoustics
Jakob Tougaard, Kristian Beedholm, Peter T. Madsen
Summary: This article reviews the evidence available after 2015 regarding the criteria for noise-induced hearing loss in marine mammals. It analyzes the thresholds for impulsive sounds and non-impulsive sounds in two functional hearing groups. The current thresholds have strong support for certain cetaceans and seals, but discrepancies exist in other frequency ranges, calling for further studies.
JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA
(2022)
Article
Multidisciplinary Sciences
Christian Bergler, Simeon Q. Smeele, Stephen A. Tyndel, Alexander Barnhill, Sara T. Ortiz, Ammie K. Kalan, Rachael Xi Cheng, Signe Brinklov, Anna N. Osiecka, Jakob Tougaard, Freja Jakobsen, Magnus Wahlberg, Elmar Noeth, Andreas Maier, Barbara C. Klump
Summary: Bioacoustic research often relies on manual identification of target species or call types, which is time-consuming and error-prone. This study presents an open-source deep learning framework, ANIMAL-SPOT, which achieves high accuracy in identifying bioacoustic signals without requiring animal-specific machine learning approaches. The framework is accessible to a broad audience and does not rely on expert knowledge or special computing resources.
SCIENTIFIC REPORTS
(2022)
Article
Acoustics
K. Beedholm, M. Ladegaard, P. T. Madsen, P. L. Tyack
Summary: Most studies on echolocating toothed whales measure short-latency auditory brainstem responses (ABRs) to clicks and echoes. However, less is known about longer-latency cortical AEPs. This study shows that click-related AEP peaks with longer latencies than 99% of click intervals are present, suggesting ongoing higher-order echo processing even during slow clicking. The findings also suggest that the identified long-latency AEPs may enable hearing sensitivity measurements at lower frequencies than current methods.
JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA
(2023)
Article
Multidisciplinary Sciences
Peter T. Madsen, Ursula Siebert, Coen P. H. Elemans
Summary: Toothed whales use their nasal passages to produce sound, which allows them to generate echolocation signals at depths of over 1000 meters. This finding provides a physiological basis for understanding the vocal repertoires and social communication of these whales.
Article
Multidisciplinary Sciences
Dominik Andre Nachtsheim, Mark Johnson, Tobias Schaffeld, Abbo van Neer, Peter T. Madsen, Charlotte R. Findlay, Laia Rojano-Donate, Jonas Teilmann, Lonnie Mikkelsen, Johannes Baltzer, Andreas Ruser, Ursula Siebert, Joseph G. Schnitzler
Summary: The North Sea experiences heavy ship traffic due to increasing human activities. This study investigates the hypothesis that harbour seals in the North Sea are repeatedly exposed to high-intensity vessel noise. A total of 133 vessel passes were detected with noise levels > 97 dB re 1 mu Pa RMS in the 2 kHz decidecade band. Tagged seals spent most of their time within Marine Protected Areas but were still exposed to vessel noise. Only 32% of vessel passes were related to registered vessels according to AIS data.
SCIENTIFIC REPORTS
(2023)
Article
Biology
Laura Stidsholt, Antoniya Hubancheva, Stefan Greif, Holger R. Goerlitz, Mark Johnson, Yossi Yovel, Peter T. Madsen, Yuuki Y. Watanabe
Summary: Using bat-borne tags and DNA metabarcoding of feces, this study confirms that greater mouse-eared bats make immediate foraging decisions based on changes in the environment and prey profitabilty. Despite lower success rates, bats primarily rely on high-risk, high-gain gleaning of ground prey due to their larger size, but switch to aerial hunting when the profitability of ground prey decreases.
Article
Multidisciplinary Sciences
Charlotte R. Findlay, Laia Rojano-Donate, Jakob Tougaard, Mark P. Johnson, Peter Teglberg Madsen
Summary: Global reductions in underwater radiated noise levels from cargo vessels are necessary to mitigate the accumulative impacts on marine wildlife. By utilizing a vessel exposure simulation model, we demonstrate that reducing vessel source levels through slowdowns and technological modifications can significantly decrease the area exposed to ship noise. Furthermore, despite the longer duration it takes for a slower vessel to pass an animal, slowdowns effectively mitigate all impacts to marine mammals. Hence, we suggest implementing speed reductions as an immediate solution to reduce cumulative noise impacts, which can be scalable from local areas to global ocean basins. Additionally, routing vessels away from critical habitats and employing technological modifications to minimize vessel noise can further supplement these efforts.
Article
Multidisciplinary Sciences
Simone K. A. Videsen, Malene Simon, Fredrik Christiansen, Ari Friedlaender, Jeremy Goldbogen, Hans Malte, Paolo Segre, Tobias Wang, Mark Johnson, Peter T. Madsen
Summary: Giant rorqual whales have a massive food turnover driven by a high-intake lunge feeding style, which is considered the largest biomechanical action. This feeding behavior, although high-drag, is energetically cheap, allowing rorquals to be flexible in exploiting different prey patches and resilient to environmental fluctuations and disturbance. As a result, the ecological role and food turnover of these marine giants are likely overestimated.
Article
Multidisciplinary Sciences
Ciska Bakkeren, Michael Ladegaard, Kirstin Anderson Nansen, Magnus Wahlberg, Peter Teglberg Madsen, Laia Rojano-Donate
Summary: The dive response in marine mammals allows them to adapt their oxygen consumption to breath-hold duration and depth by adjusting peripheral vasoconstriction and heart rate. A study on a trained harbor porpoise showed that it halves its diving heart rate when blindfolded, indicating that sensory deprivation can enhance the dive response. This suggests that visual stimuli may play a more significant role in echolocating toothed whales than previously believed.
Article
Acoustics
Jamie Donald John Macaulay, Laia Rojano-Donate, Michael Ladegaard, Jakob Tougaard, Jonas Teilmann, Tiago A. Marques, Ursula Siebert, Peter Teglberg Madsen
Summary: This study investigates the impact of behavioral changes on the interpretation of acoustic monitoring data. The results show that the behavioral state of harbour porpoises has a significant effect on the probability of detecting clicks, highlighting the importance of considering animal behavior in the analysis of animal abundance.
JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA
(2023)
Article
Multidisciplinary Sciences
Siri L. Elmegaard, Jonas Teilmann, Laia Rojano-Donate, Dennis Brennecke, Lonnie Mikkelsen, Jeppe D. Balle, Ulrich Gosewinkel, Line A. Kyhn, Pernille Tonnesen, Magnus Wahlberg, Andreas Ruser, Ursula Siebert, Peter Teglberg Madsen
Summary: This study investigates the physiological and behavioral responses of harbor porpoises to a commercial acoustic harassment device (AHD). The results show that AHD exposure can trigger startled responses, flight responses, and cardiac responses in porpoises, potentially impacting their blood-gas management, breath-hold capability, energy balance, stress levels, and risk of by-catch.
SCIENTIFIC REPORTS
(2023)
Article
Biodiversity Conservation
Elizabeth A. McHuron, Stephanie Adamczak, John P. Y. Arnould, Erin Ashe, Cormac Booth, W. Don Bowen, Fredrik Christiansen, Magda Chudzinska, Daniel P. Costa, Andreas Fahlman, Nicholas A. Farmer, Sarah M. E. Fortune, Cara A. Gallagher, Kelly A. Keen, Peter T. Madsen, Clive R. McMahon, Jacob Nabe-Nielsen, Dawn P. Noren, Shawn R. Noren, Enrico Pirotta, David A. S. Rosen, Cassie N. Speakman, Stella Villegas-Amtmann, Rob Williams
Summary: Bioenergetic approaches are used to understand the impact of changing aquatic environments on marine mammal populations. However, there is still much we don't know about marine mammal bioenergetics, which hinders the application of bioenergetic studies in policy decisions. This study identified high-priority unanswered questions in marine mammal bioenergetics, emphasizing those relevant to conservation and management. The results provide a framework for setting research priorities and informing policies to better protect marine mammal populations.
CONSERVATION PHYSIOLOGY
(2022)