Jakob Tougaard

Jakob Tougaard
Aarhus University | AU · Department of Ecoscience

Ph.D.

About

127
Publications
55,508
Reads
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3,654
Citations
Citations since 2017
43 Research Items
1775 Citations
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Introduction
Works with bioacoustics of marine mammals and effects of anthropogenic noise. Currently involved in EU-LIFE projects SAMBAH and BIAS. The goal of SAMBAH is to obtain a population estimate for harbour porpoises in the Baltic Sea by means passive acoustic dataloggers. Web-page: http://www.sambah.org/ The goal of BIAS is to describe the soundscape of the Baltic Sea and the human contribution to the noise. This will be through modelling based on measurements. Web-page: http://www.bias-project.eu/
Additional affiliations
December 2003 - present
Aarhus University
Position
  • Senior Researcher
January 2003 - November 2003
Orbicon
Position
  • Consultant
January 1998 - December 2002
University of Southern Denmark
Position
  • PostDoc Position
Education
September 1992 - June 1998
Aarhus University
Field of study
  • Bioacoustics
September 1987 - July 1992
Aarhus University
Field of study
  • Biology

Publications

Publications (127)
Article
Full-text available
Bioacoustic research spans a wide range of biological questions and applications, relying on identification of target species or smaller acoustic units, such as distinct call types. However, manually identifying the signal of interest is time-intensive, error-prone, and becomes unfeasible with large data volumes. Therefore, machine-driven algorithm...
Article
Full-text available
Intense sound sources, such as pile driving, airguns, and military sonars, have the potential to inflict hearing loss in marine mammals and are, therefore, regulated in many countries. The most recent criteria for noise induced hearing loss are based on empirical data collected until 2015 and recommend frequency-weighted and species group-specific...
Article
Full-text available
The loud, impulsive, broadband underwater sounds produced during offshore pile driving are known to have auditory and behavioral effects on harbor porpoises (Phocoena phocoena) in the areas around piling sites. Thresholds to prevent behavioral effects have not yet been set, and it is unclear whether or not auditory frequency weighting of piling sou...
Article
Full-text available
Abstract Knowing the abundance of a population is a crucial component to assess its conservation status and develop effective conservation plans. For most cetaceans, abundance estimation is difficult given their cryptic and mobile nature, especially when the population is small and has a transnational distribution. In the Baltic Sea, the number of...
Article
Full-text available
A longer Arctic open water season is expected to increase underwater noise levels due to anthropogenic activities such as shipping, seismic surveys, sonar, and construction. Many Arctic marine mammal species depend on sound for communication, navigation, and foraging, therefore quantifying underwater noise levels is critical for documenting change...
Conference Paper
No PDF available ABSTRACT The JOMOPANS project created one year of soundscape maps of the North Sea, based on ship information from the Automatic Identification System (AIS) and a ship source model. This assessed the potential impact of ship noise on the marine ecosystem through the masking of communication and other relevant acoustic signals. Spec...
Preprint
Knowing the abundance of a population is a crucial component to assess its conservation status and develop effective conservation plans. For most cetaceans, abundance estimation is difficult given their cryptic and mobile nature, especially when the population is small and has a transnational distribution. In the Baltic Sea, the number of harbour p...
Article
No PDF available ABSTRACT The Joint Monitoring Programme for Ambient Noise North Sea (JOMOPANS) aimed to develop a framework for managers, planners and other stakeholders to incorporate the effects of ambient noise in their Good Environmental Status (GES) assessment of the North Sea. This was accomplished by generating spatial maps of the anthropog...
Article
Full-text available
Male harbor seals (Phoca vitulina) produce stereotypic underwater roars during the mating season. It remains unclear to what extent roar structures vary due to predation levels. Here, seal roars from waters with many (Iceland) and few (Denmark and Sweden) predators were compared. Most Icelandic roars included a long pulse train and a pause. Iceland...
Book
Full-text available
We report the developments and results of the ECOMAR project, which have taken place 2018-2020 and was funded by THE VELUX FOUNDATIONS. ECOMAR has established state-of-the-art data sets for the distribution of human activities and pressures as well as ecosystem components in Danish marine waters. ECOMAR has mapped the combined effects of multiple h...
Article
Full-text available
Offshore wind turbines are increasingly abundant sources of underwater low frequency noise. This increase raises concern for the cumulative contribution of wind farms to the underwater soundscape and possible impact on marine ecosystems. Here, available measurements of underwater noise from different wind turbines during operation are reviewed to s...
Data
This report contains, as said in the title, the supplementary material to the synthesis report from the ECOMAR project (2018-2020). The supplementary material consists of three parts: 1) Annex A, being the data sets and layers dealing with human pressures and activities, 2) Annex B, being the data sets related to ecosystem components and analogue d...
Article
Full-text available
Underwater noise pollution from impulsive sources (e.g. explosions, seismic airguns, percussive pile driving) can affect marine fauna through mortality, physical injury, auditory damage, physiological stress, acoustic masking, and behavioural responses. Given the potential for large-scale impact on marine ecosystems, some countries are now monitori...
Article
Full-text available
The most common cetacean in the North Sea is the harbor porpoise (Phocoena phocoena). Underwater noise is increasingly recognized as a source of impact on the marine environment and seismic airguns were one of the first man-made high intensity sound source to receive attention with respect to potential impact on marine mammals. In this study, we in...
Article
Often perceived as environmentally benign, 'green' renewable energy technologies have ecological costs that are often overlooked, especially those occurring below the waterline. After briefly discussing the impacts of hydropower on freshwater and marine organisms, we focus this review on the impacts of marine renewable energy devices (MREDs) on und...
Article
Full-text available
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 c...
Article
Full-text available
During last decades, anthropogenic underwater sound and its chronic impact on marine species have been recognised as an environmental protection challenge. At the same time, studies on the spatial and temporal variability of ambient sound, and how it is affected by biotic, abiotic and anthropogenic factors are lacking. This paper presents analysis...
Conference Paper
Full-text available
High-latitude regions like the Arctic Ocean are becoming increasingly important as global warming makes them more accessible, raising economic and political interests. Sea ice reduction is facilitating resource exploration, marine transport and other activities. Warming waters and changing sea ice conditions lead to shifts in ecosystems. Resource e...
Article
Full-text available
Harbour porpoises are well-suited for passive acoustic monitoring (PAM) as they produce highly stereotyped narrow-band high-frequency (NBHF) echolocation clicks. PAM systems must be coupled with a classification algorithm to identify the signals of interest. Here, the authors present a harbour porpoise click classifier (PorCC) developed in matlab,...
Article
Seismic surveys increasingly operate in deeper Arctic waters with propagation conditions and marine mammal fauna different from the better-studied temperate, or shallow-water, regions. Using 31 calibrated sound recorders, we quantified noise contributions from four concurrent seismic surveys in Baffin Bay, Greenland, to estimate their potential imp...
Conference Paper
Harbour porpoises (Phocoena phocoena) are regularly monitored to assess how they are impacted by the construction and operation of offshore wind farms. A suitable method to do this is passive acoustic monitoring (PAM) by stationary hydrophones, for example CPODs. These devices provide information on echolocation click activity, which can then be an...
Article
Full-text available
Much effort is currently directed at describing the behavioral reactions of marine mammals following exposure to sound with the aim of deriving generalized thresholds and dose-response functions. The perceived loudness of a given sound is a candidate for a common metric for sound exposure. The loudness of a signal relates to various factors, includ...
Article
Knowledge on spatial and seasonal distribution of species is crucial when designing protected areas and implementing management actions. The Baltic Proper harbour porpoise (Phocoena phocoena) population is critically endangered, and its distribution is virtually unknown. Here, we used passive acoustic monitoring and species distribution models to d...
Article
Full-text available
Automatic click detectors and full-bandwidth sound recorders are widely used in passive acoustic monitoring of small cetaceans. Detection of these signals depends on a variety of factors, including signal to noise ratio. Passive acoustic monitoring is often used to study impact of underwater noise on small cetaceans, but as detection probability is...
Technical Report
Full-text available
The harbour porpoise is protected by the Habitats Directive Annexes II and IV. This means that a system of strict protection shall be established throughout its natural range (Annex IV), and that sites of significant importance to the species should be designated and protected (special areas of conservation) (Annex II). Preferred foraging habitats...
Article
Full-text available
A key question related to regulating noise from pile driving, air guns, and sonars is how to take into account the hearing abilities of different animals by means of auditory frequency weighting. Recordings of pile driving sounds, both in the presence and absence of a bubble cur-tain, were evaluated against recent thresholds for temporary threshold...
Article
Full-text available
Effects of constructing the DanTysk offshore wind farm (German Bight, 80 turbines, 6 m diameter foundations) were studied by passive acoustic monitoring of pile-driving noise and harbour porpoise Phocoena phocoena echolocation. An acoustic deterrence device (seal scarer) was used to protect porpoises from hearing loss and bubble curtains were used...
Article
Full-text available
Acoustic harassment devices (AHD) or ‘seal scarers’ are used extensively, not only to deter seals from fisheries, but also as mitigation tools to deter marine mammals from potentially harmful sound sources, such as offshore pile driving. To test the effectiveness of AHDs, we conducted two studies with similar experimental set-ups on two key species...
Article
Male harbor seals gather around breeding sites for competitive mating displays. Here, they produce underwater vocalizations possibly to attract females and/or scare off other males. These calls offer prospects for passive acoustic monitoring. Acoustic monitoring requires a good understanding of natural variation in calling behavior both temporally...
Article
Full-text available
The bycatch of harbour porpoise Phocoena phocoena is an issue of major concern for fisheries management and for porpoise conservation. We used high-resolution spatial and temporal data on porpoise abundance and fishing effort from the Danish Skagerrak Sea to identify areas with potentially higher and lower risk of porpoise bycatch. From May 2010 to...
Article
Full-text available
Cetacean monitoring is essential in determining the status of a population. Different monitoring methods should reflect the real trends in abundance and patterns in distribution, and results should therefore ideally be independent of the selected method. Here, we compare two independent methods of describing harbour porpoise (Phocoena phocoena) rel...
Data
C-POD recording periods. Successful data acquisition of the 36 C-POD stations included in the study. Data coverage is variable due to loss of equipment, malfunctioning equipment or loss of battery power. Also, the day of deployment/retrievement of equipment was excluded from the analysis, to only include full days. (TIFF)
Conference Paper
The C-POD logger is a widely used instrument for passive acoustic monitoring of harbor porpoises, but the absence of a continuous recording in this device makes it difficult to verify its performance. An alternative but more labor-intensive approach is to use a wideband sound recorder and off-line detection software. Here we compare the performance...
Poster
Full-text available
Acoustic harassment devices (AHDs) are commonly used as mitigation devices during construction of offshore wind farms, to deter marine mammals and thus protect them from hearing damage caused by pile driving noise. However, especially for seals, it is not well known how effective this method is. Here we investigated whether a simulated acoustic har...
Article
Full-text available
Despite a major research effort, no generally accepted exposure limits are available for harbor porpoises. Recent studies of the temporary threshold shift (TTS) in porpoises indicate that the sound exposure levels (SELs) required to induce low levels of TTS depend on stimulus frequency and roughly parallel the shape of the audiogram. A number of st...
Article
We estimated the long-range effects of air gun array noise on marine mammal communication ranges in the Southern Ocean. Air gun impulses are subject to significant distortion during propagation, potentially resulting in a quasi-continuous sound. Propagation modeling to estimate the received waveform was conducted. A leaky integrator was used as a h...
Article
The project conducts application-oriented research on impacts of underwater noise on marine vertebrates in the North and Baltic Seas. In distinct subprojects, the hearing sensitivity of harbor porpoises and gray seals as well as the acoustic tolerance limit of harbor porpoises to impulsive noise from pile driving and stress reactions caused by anth...
Article
Full-text available
Management of the impact of underwater sound is an emerging concern worldwide. Several countries are in the process of implementing regulatory legislations. In Europe, the Marine Strategy Framework Directive was launched in 2008. This framework addresses noise impacts and the recommendation is to deal with it on a regional level. The Baltic Sea is...
Article
Full-text available
Airguns used in seismic surveys are among the most prevalent and powerful anthropogenic noise sources in marine habitats. They are designed to produce most energy below 100 Hz, but the pulses have also been reported to contain medium-to-high frequency components with the potential to affect small marine mammals, which have their best hearing sensit...
Article
Full-text available
Underwater noise was recorded from the Wavestar wave energy converter; a full-scale hydraulic point absorber, placed on a jack-up rig on the Danish North Sea coast. Noise was recorded 25 m from the converter with an autonomous recording unit (10 Hz to 20 kHz bandwidth). Median sound pressure levels (L<sub>eq</sub>) in third-octave bands during oper...
Conference Paper
Full-text available
he discussion was divided into a first section, where the audience addressed specific questions to the presenters and a second part, where the questions distributed by the chairs beforehand were discussed. One topic covered in the first part was the distribution of sound sources in the water column (i.e. in different water depths and horizontal dis...
Article
Full-text available
Several studies have shown that pingers mitigate porpoise bycatch and thus pinger use is now mandatory in some fisheries - although the long-term effects of pinger exposure on porpoises have not been well studied. The effects of 2 types of pingers (Airmar: 10 kHz tone; Save-Wave Black Saver: 30-160 kHz sweep) on the presence of wild harbour porpois...
Article
Full-text available
The data accompanies the paper "Characteristics and propagation of airgun pulses in shallow water with implications for effects on small marine mammals" published in PLOS ONE, July 27, 2015, DOI: 10.1371/journal.pone.0133436. Data is provided as 1 second .wav files (50 ms before peak to 950 ms after peak) for each airgun pulse filtered with a 5 Hz...
Article
Full-text available
The impact of underwater noise on marine life calls for identification of exposure criteria to inform mitigation. Here we review recent experimental evidence with focus on the high-frequency cetaceans and discuss scientifically-based initial exposure criteria. A range of new TTS experiments suggest that harbour and finless porpoises are more sensit...
Article
Full-text available
Growing ship traffic worldwide has led to increased vessel noise with possible negative impacts on marine life. Most research has focused on low frequency components of ship noise, but for high-frequency specialists, such as the harbor porpoise (Phocoena phocoena), medium-to-high frequency noise components are likely more of a concern. To test for...
Conference Paper
SAMBAH (Static Acoustic Monitoring of the Baltic Sea Harbor Porpoise) is an EU LIFE + -funded project with the primary goal of estimating the abundance and distribution of the critically endangered Baltic Sea harbor porpoise. From May 2011 to April 2013, project members in all EU countries around the Baltic Sea undertook a static acoustic survey us...
Technical Report
Full-text available
In 2012 one 2D and three 3D seismic surveys were simultaneously conducted in Baffin Bay, West Greenland. The surveys were monitored using 21 acoustic dataloggers deployed in and around the seismic sites and CTD data were collected throughout the seismic season. These environmental data together with bathymetry measurements collected by the seismic...