Between 1991 and 2011, 137 harbour porpoises (Phocoena phocoena) died as a result of attacks by bottlenose dolphins (Tursiops truncatus) in Cardigan Bay. The suggested reasons for these non-predatory aggressive…
Helicopter Long Range Active Sonar (HELRAS) is deployed from navy helicopters to detect submarines. Its worldwide use by NATO navies is expected to increase due to the increasing need to…
Underwater impulsive sounds may affect the behavior of harbor porpoises within a certain distance from the sound source. To determine the 50% threshold received sound exposure level (SEL) of an…
Sound is the main means of communication for cetaceans, and studying their vocal behaviour can reveal important information about their activity patterns. As static acoustic monitoring (SAM) of whales, dolphins,…
Active sound emitters (‘pingers’) are used in several gillnet fisheries to reduce bycatch of small cetaceans, and/or to reduce depredation by dolphins. Here, we review studies conducted to determine how…
For many toothed whales, two predominant and multifunctional spatial positions occur between a mother/calf pair after birth: (1) the echelon position and (2) the infant position. Other nonpredominant positions also…
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)…
During ship surveys harbor porpoises are only visible when breaking the sea surface to breathe, while during aerial surveys they may be seen down to 2 m below the surface.…
Harbour porpoises Phocoena phocoena are unintentionally caught in gillnets. Although the effectiveness of by-catch mitigation measures has been evaluated many times, only a few studies have investigated the behavioural patterns…
This study presents bioacoustic recordings in combination with movements and diving behavior of three free-ranging harbor porpoises (a female and two males) in Danish waters. Each porpoise was equipped with…