Topic
Phocoena
About: Phocoena is a research topic. Over the lifetime, 1039 publications have been published within this topic receiving 28086 citations.
Papers published on a yearly basis
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Papers
TL;DR: The SCANS (Small Cetacean Abundance in the North Sea) survey was conducted in summer 1994 and was designed to generate precise and unbiased abundance estimates.
Abstract: 1. The status of small cetaceans in the North Sea and adjacent waters has been of concern for many years. Shipboard and aerial line transect surveys were conducted to provide accurate and precise estimates of abundance as a basis for conservation strategy in European waters. 2. The survey, known as SCANS (Small Cetacean Abundance in the North Sea), was conducted in summer 1994 and designed to generate precise and unbiased abundance estimates. Thus the intensity of survey was high, and data collection and analysis methods allowed for the probability of detection of animals on the transect line being less than unity and, for shipboard surveys, also allowed for animal movement in response to the survey platform. 3. Shipboard transects covered 20 000 km in an area of 890 000 km2. Aerial transects covered 7000 km in an area of 150 000 km2. 4. Three species dominated the data. Harbour porpoise Phocoena phocoena were encountered throughout the survey area except in the Channel and the southern North Sea. Whitebeaked dolphin Lagenorhynchus albirostris and minke whale Balaenoptera acutorostrata were found mainly in the north-western North Sea. 5. Phocoena phocoena abundance for the entire survey area was estimated as 341 366 [coefficient of variation (CV) = 0.14; 95% confidence interval (CI) = 260 000-449 000]. The estimated number of B. acutorostrata was 8445 (CV = 0.24; 95% CI 5000-13 500). The estimate for L. albirostris based on confirmed sightings of this species was 7856 (CV = 0.30; 95% CI = 4000-13 000). When Atlantic whitesided dolphin Lagenorhynchus acutus and Lagenorhynchus spp. sightings were included, this estimate increased to 11 760 (CV = 0.26; 95% CI 5900-18 500). 6. Shortbeaked common dolphin Delphinus delphis were found almost exclusively in the Celtic Sea. Abundance was estimated as 75 450 (CV = 0.67; 95% CI = 23 000-149 000). 7. Current assessments and recommendations by international fora concerning the impact on P. phocoena of bycatch in gillnet fisheries in the North Sea and adjacent waters are based on these estimates.
471 citations
TL;DR: To determine the potential use of eDNA for genetic monitoring, specific primers that amplify short mitochondrial DNA sequences were used to detect the presence of a marine mammal, the harbor porpoise, in a controlled environment and in natural marine locations.
Abstract: 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 freshwater ecosystems. Detecting species in the marine environment using eDNA potentially offers a greater challenge due to the greater dilution, amount of mixing and salinity compared with most freshwater ecosystems. To determine the potential use of eDNA for genetic monitoring we used specific primers that amplify short mitochondrial DNA sequences to detect the presence of a marine mammal, the harbor porpoise, Phocoena phocoena, in a controlled environment and in natural marine locations. The reliability of the genetic detections was investigated by comparing with detections of harbor porpoise echolocation clicks by static acoustic monitoring devices. While we were able to consistently genetically detect the target species under controlled conditions, the results from natural locations were less consistent and detection by eDNA was less successful than acoustic detections. However, at one site we detected long-finned pilot whale, Globicephala melas, a species rarely sighted in the Baltic. Therefore, with optimization aimed towards processing larger volumes of seawater this method has the potential to compliment current visual and acoustic methods of species detection of marine mammals.
367 citations
TL;DR: Findings are consistent with a causal (immunotoxic) relationship between PCB exposure and infectious disease mortality, and they provide a framework for future quantitative risk‐assessment analyses of porpoise populations of known size and PCB exposure.
Abstract: To investigate possible relationships between polychlorinated biphenyl (PCB) exposure and infectious disease mortality in harbor porpoises (Phocoena phocoena) in United Kingdom waters, summed blubber concentrations of 25 chlorobiphenyl congeners (Σ25CB) in healthy harbor porpoises that died of acute physical trauma (mainly by-catch; n = 175) were compared with Σ25CB values in animals that died of infectious disease (n = 82). The infectious disease group had significantly greater Σ25CB values (mean, 27.6 mg/kg lipid) than the physical trauma group (mean, 13.6 mg/kg lipid;p 0.55). These findings are consistent with a causal (immunotoxic) relationship between PCB exposure and infectious disease mortality, and they provide a framework for future quantitative risk-assessment analyses of porpoise populations of known size and PCB exposure.
281 citations
TL;DR: The stomachs of 17 cetaceans of seven species yielded 18,164 fish otoliths representing over 51 species, 40 genera, and 22 families, and it is indicated that they routinely forage in depths of 650–800 ft (200–250 m), and a few such as Kogia simus may descend to 1000‴ft (300‴m) or deeper.
Abstract: The stomachs of 17 cetaceans of seven species (3 Kogia simus, 5 Stenella longirostris, 3 S. graffmani, 2 Lagenorhynchus obliquidens, 2 Delphinus delphis, 1 Lissodelphis borealis, and 1 Phocoena sin...
257 citations
TL;DR: Pile driving during offshore windfarm construction goes along with considerable noise emissions that potentially harm marine mammals in the vicinity and may cause large scale distur- bances, and the response of harbour porpoises to pile driving lasted much longer than previously reported.
Abstract: Pile driving during offshore windfarm construction goes along with considerable noise emissions that potentially harm marine mammals in the vicinity and may cause large scale distur- bances. Information on the scale of such disturbances is limited. Therefore, assessment and evalua- tion of the effects of offshore construction on marine mammals is difficult. During summer 2008, 91 monopile foundations were driven into the seabed during construction of the offshore wind farm Horns Rev II in the Danish North Sea. We investigated the spatial and temporal scale of behavioural responses of harbour porpoises Phocoena phocoena to construction noise using passive acoustic monitoring devices (T-PODs) deployed in a gradient sampling design. Porpoise acoustic activity was reduced by 100% during 1 h after pile driving and stayed below normal levels for 24 to 72 h at a distance of 2.6 km from the construction site. This period gradually decreased with increasing distance. A negative effect was detectable out to a mean distance of 17.8 km. At 22 km it was no longer apparent, instead, porpoise activity temporarily increased. Out to a distance of 4.7 km, the recovery time was longer than most pauses between pile driving events. Consequently, porpoise activity and possibly abundance were reduced over the entire 5 mo construction period. The beha- vioural response of harbour porpoises to pile driving lasted much longer than previously reported. This information should be considered when planning future wind farm construction.
240 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2025 | 29 |
| 2024 | 26 |
| 2023 | 72 |
| 2022 | 60 |
| 2021 | 42 |
| 2020 | 49 |