Line A Kyhn

Line A Kyhn
Aarhus University | AU · Department of Bioscience

About

41
Publications
13,651
Reads
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1,421
Citations
Citations since 2017
11 Research Items
841 Citations
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2017201820192020202120222023050100150
2017201820192020202120222023050100150
2017201820192020202120222023050100150

Publications

Publications (41)
Article
Full-text available
Evaluating populational trends of health condition has become an important topic for marine mammal populations under the Marine Strategy Framework Directive (MSFD). In the Baltic Sea, under the recommendation of Helsinki Commission (HELCOM), efforts have been undertaken to use blubber thickness as an indicator of energy reserves in marine mammals....
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...
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
Full-text available
In marine environments noise from human activities is increasing dramatically, causing animals to alter their behavior and forage less efficiently. These alterations incur energetic costs that can result in reproductive failure, death, and may ultimately influence population viability; yet the link between population dynamics and individual energet...
Article
The overall aim of the present study was to assess human exposure to environmental contaminants from consumption of harbour seal (Phoca vitulina) meat in the southwestern Baltic Sea. For this purpose, muscle tissue from harbour seals (n = 27) was sampled from Danish locations in the period 2005-2015 and analysed for concentrations of total mercury...
Article
Cetaceans use sound for communication, navigation and finding prey. Most extant odontocetes produce broadband (BB) biosonar clicks covering frequency ranges from tens of kilohertz to 150-170 kHz. In contrast, the biosonar clicks of some odontocetes are unique, being narrow in bandwidth with high centroid frequency (NBHF), peak frequencies being at...
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...
Article
Cetaceans use sound for communication, navigation and finding prey. Most extant odontocetes produce broadband (BB) biosonar clicks covering frequency ranges from tens of kilohertz to 150-170 kHz. In contrast, the biosonar clicks of some odontocetes are unique, being narrow in bandwidth with high centroid frequency (NBHF), peak frequencies being at...
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
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)
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 critically endangered Spitsbergen stock of bowhead whale (Balaena mysticetus) seems to be increasing. However, research effort has also been increasing confounding a firm conclusion. A systematic aerial survey for walrus (Odobaenus rosmarus), applying distance sampling methodology in part of the Northeast Water Polynya (NEW), revealed a ‘bycatc...
Article
Full-text available
Managing animal units is essential in biological conservation and requires spatial and temporal identification of such units. Since even neighbouring populations often have different conservation status and face different levels of anthropogenic pressure, detailed knowledge of population structure, seasonal range and overlap with animals from neigh...
Poster
Full-text available
t is not generally possible to determine acoustically how far a vocalising cetacean is from from a single hydrophone, but landmark sequences do make this possible. These sequences occur in the click trains made by porpoises, and show a linear reduction over time in the interval between the clicks as the animal swims towards a target of interest to...
Article
Full-text available
Human pressure on the environment is expanding and intensifying, especially in coastal and offshore areas. Major contributors to this are the current push for offshore renewable energy sources, which are thought of as environmentally friendly sources of power, as well as the continued demand for petroleum. Human disturbances, including the noise al...
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...
Article
Full-text available
The densities of common breeding birds in the Zackenberg valley, Greenland, such as Sanderling Calidris alba and Dunlin C. alpina, were relatively high compared to previous years. Breeding Long-tailed Skuas Stercorarius longicaudus, however, were again found in low numbers, most likely reflecting the observed low number of lemmings. Only two of the...
Article
Full-text available
Odontocetes produce a range of different echolocation clicks but four groups in different families have converged on producing the same stereotyped narrow band high frequency (NBHF) click. In microchiropteran bats, sympatric species have evolved the use of different acoustic niches and subtly different echolocation signals to avoid competition amon...
Article
Full-text available
Most plant species have a range of traits that deter herbivores. However, understanding of how different defences are related to one another is surprisingly weak. Many authors argue that defence traits trade off against one another, while others argue that they form coordinated defence syndromes. We collected a dataset of unprecedented taxonomic an...
Article
Full-text available
The exploitation of non-invasive samples has been widely used in genetic monitoring of terrestrial species. In aquatic ecosystems, non-invasive samples such as feces, shed hair or skin, are less accessible. However, the use of environmental DNA (eDNA) has recently been shown to be an effective tool for genetic monitoring of species presence in fres...
Article
Pile driving of large steel monopiles in offshore waters has increased rapidly in recent years due to the expanding development of offshore wind energy. In particular, Phocoena phocoena (harbor porpoise) has been the focus of attention with respect to a possible negative impact. Impact pile driving, where a large steel monopile is driven 20-30 m in...
Article
Full-text available
Monitoring abundance and population trends of small odontocetes is notoriously difficult and labor intensive. There is a need to develop alternative methods to the traditional visual line transect surveys, especially for low density areas. Here, the prospect of obtaining robust density estimates for porpoises by passive acoustic monitoring (PAM) is...
Article
Full-text available
In 2009, monitoring continued of bird populations in a 15.8 km2 designated area at Zackenberg Research Station in central Northeast Greenland. Results are presented and compared with those from previous seasons (1995 – 2008). Despite the extremely limited spring snow cover in 2009, nest initiation was early for Dunlin (Calidris alpina) and Red Knot...
Article
Full-text available
• It has long been believed that plant species from the tropics have higher levels of traits associated with resistance to herbivores than do species from higher latitudes. A meta-analysis recently showed that the published literature does not support this theory. However, the idea has never been tested using data gathered with consistent methods f...
Article
Full-text available
• It has long been believed that plant species from the tropics have higher levels of traits associated with resistance to herbivores than do species from higher latitudes. A meta-analysis recently showed that the published literature does not support this theory. However, the idea has never been tested using data gathered with consistent methods f...
Article
Full-text available
An increasing number of smaller odontocetes have recently been shown to produce stereotyped narrow-band high-frequency (NBHF) echolocation clicks. Click source parameters of NBHF clicks are very similar, and it is unclear whether the sonars of individual NBHF species are adapted to specific habitats or the presence of other NBHF species. Here, we t...
Article
Full-text available
Toothed whales depend on echolocation for orientation and prey localization, and source parameters of echolocation clicks from free-ranging animals therefore convey valuable information about the acoustic physiology and behavioral ecology of the recorded species. Recordings of wild hourglass (Lagenorhynchus cruciger) and Hector's dolphins (Cephalor...
Article
Acoustic harassment and deterrent devices have become increasingly popular mitigation tools for negotiating the impacts of marine mammals on fisheries. The rationale for their variable effectiveness remains unexplained, but high variability in the surrounding acoustic field may be relevant. In the present study, the sound fields of one acoustic har...
Article
This chapter describes and analyzes the predator–prey dynamics representative of the terrestrial ecosystem in Zackenbergdalen. By using comprehensive, temporally replicated data on the collared lemming and its predators, the chapter focuses on the predator–lemming dynamics embracing a period of 10 years. The chapter discusses the predator–lemming m...
Article
Full-text available
The T-POD (Timing POrpoise Detector) is a self-contained acoustic data logger used for detecting and monitoring the presence of echolocation clicks of small cetaceans. It has become a standard tool in environmental impact assessments and monitoring programmes. Yet, little is known about the variability in sensitivity and detection range of T-PODs....
Article
Full-text available
The use of passive acoustic monitoring (PAM) is increasingly used as a monitoring tool in e.g environmental impact assessments. However, very few studies have focused on validating PAM data against independent observations which is critical in order to compare data from different studies and areas, and over time. In August 2007 we tested two types...
Conference Paper
Full-text available
The source properties of toothed whale echolocation clicks are essential for evaluating the performance of biosonar systems. However, such data only exist for a small number of free ranging toothed whale species. Here we present a quantitative analysis of the first recordings of echolocation sounds from hour glass dolphins (Lagenorhynchus cruciger)...

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Projects

Projects (2)
Archived project
Investigate the distribution, density and abundance of harbour porpoises in the Baltic Sea.
Archived project
Extracting high-repetition rate clicks, so called feeding buzzes, from acoustic data collected during the SAMBAH project to investigate the spatial and temporal distribution of these events.