Geographical and seasonal variation of harbour porpoise (Phocoena phocoena) presence in the German Baltic Sea revealed by passive acoustic monitoring

2007 ◽  
Vol 87 (1) ◽  
pp. 165-176 ◽  
Author(s):  
Ursula K. Verfuß ◽  
Christopher G. Honnef ◽  
Anja Meding ◽  
Michael Dähne ◽  
Roger Mundry ◽  
...  
Keyword(s):  
Seasonal Variation ◽  
Baltic Sea ◽  
Research Effort ◽  
Natura 2000 ◽  
Acoustic Monitoring ◽  
Harbour Porpoise ◽  
Passive Acoustic Monitoring ◽  
Cetacean Species ◽  
Passive Acoustic ◽  
The Impact

The harbour porpoise is the only resident cetacean species in the German Baltic Sea. Within the last several decades this harbour porpoise stock declined drastically, causing deep concern about its status. Plans of the German government for proposing Marine Protected Areas (MPAs) to implement Natura 2000 and for assessing the impact of offshore windmill constructions on the marine environment led to an increased research effort on the harbour porpoise in German waters. For the first time, long-term passive acoustic monitoring has been conducted in the German Baltic Sea from the Kiel Bight to the Pomeranian Bay from August 2002 to December 2005. Porpoise detectors (T-PODs) have been installed five to seven metres below the water surface at up to 42 measuring positions throughout the investigated area, registering the exact times of echolocation signals of passing harbour porpoises. The proportion of monitored days with porpoise detection in each quarter of the years has been analysed. A correlation of the results with the longitude of the measuring position revealed a significant decrease from west to east in the percentage of days with porpoise detections. Comparison of data gathered in the first quarters with the third quarters of the monitoring years displayed a seasonal variation with fewer days of porpoise detections in winter time than in summer time. Nevertheless, harbour porpoises have been detected year-round at most of the measuring positions in the German Baltic Sea. The present study clearly indicates a regular use of the German Baltic Sea by harbour porpoises with a geographical and seasonal variation in the usage of the German Baltic Sea. The larger numbers of harbour porpoise detections in spring to autumn compared with winter suggests that the German Baltic Sea is an important breeding and mating area for these animals.

scholarly journals Estimating the abundance of the critically endangered Baltic Proper harbour porpoise (Phocoena phocoena) population using passive acoustic monitoring

2021 ◽  
Author(s):  
Mats Amundin ◽  
Julia Carlström ◽  
Len Thomas ◽  
Ida Carlén ◽  
Jens Koblitz ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Acoustic Monitoring ◽  
Harbour Porpoise ◽  
Critically Endangered ◽  
Phocoena Phocoena ◽  
Passive Acoustic Monitoring ◽  
Animal Populations ◽  
Baltic Proper ◽  
The Baltic ◽  
Passive Acoustic

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 porpoises (Phocoena phocoena) has collapsed since the mid-20th century and the Baltic Proper harbour porpoise is listed as Critically Endangered by the IUCN; however, its abundance remains unknown. Here, one of the largest ever passive acoustic monitoring studies was carried out by eight Baltic Sea nations to estimate the abundance of the Baltic Proper harbour porpoise for the first time. By logging porpoise echolocation signals at 298 stations during May 2011-April 2013, calibrating the loggers’ spatial detection performance at sea, and measuring the click rate of tagged individuals, we estimated an abundance of 66-1,143 individuals (95% CI, point estimate 490) during May-October within the population’s proposed management border. The small abundance estimate strongly supports that the Baltic Proper harbour porpoise is facing an extremely high risk of extinction, and highlights the need for immediate and efficient conservation actions through international cooperation. It also provides a starting point in monitoring the trend of the population abundance to evaluate the effectiveness of management measures and determine its interactions with the larger neighbouring Belt Sea population. Further, we offer evidence that design-based passive acoustic monitoring can generate reliable estimates of the abundance of rare and cryptic animal populations across large spatial scales.

scholarly journals Cetacean occurrence offshore of Washington from long-term passive acoustic monitoring

2021 ◽  
Vol 168 (8) ◽  
Author(s):  
Ally Rice ◽  
Amanda J. Debich ◽  
Ana Širović ◽  
Erin M. Oleson ◽  
Jennifer S. Trickey ◽  
...  
Keyword(s):  
Habitat Use ◽  
Sperm Whale ◽  
Acoustic Monitoring ◽  
Conservation Strategies ◽  
Physeter Macrocephalus ◽  
Passive Acoustic Monitoring ◽  
Temporal Separation ◽  
Cetacean Species ◽  
Beaked Whales ◽  
Passive Acoustic

AbstractA variety of cetacean species inhabit the productive waters offshore of Washington State, USA. Although the general presence of many of these species has been documented in this region, our understanding of fine-scale habitat use is limited. Here, passive acoustic monitoring was used to investigate the spatial and temporal distributions of ten cetacean species at three locations offshore of Washington. Between 2004 and 2013, a total of 2845 days of recordings were collected from sites on the continental shelf and slope, and in a submarine canyon. Acoustic presence was higher for all species at sites farther offshore. Detections were highest during the fall and winter for blue (Balaenoptera musculus), fin (B. physalus), and humpback whales (Megaptera novaeangliae), likely related to reproductive behavior, while minke whales (B. acutorostrata) were only detected on two days. Odontocetes showed temporal separation, with sperm whale (Physeter macrocephalus) detections highest in spring, Risso’s (Grampus griseus) and Pacific white-sided dolphins (Lagenorhynchus obliquidens) highest in summer, and Stejneger’s beaked whales (Mesoplodon stejnegeri), Cuvier’s beaked whales (Ziphius cavirostris), and the BW37V signal type highest in winter or spring. There was interannual variation in detections for most mysticete species, which may be linked to oceanographic conditions: blue and fin whale detections increased during 2007 and 2008, and fin and humpback whale detections increased in 2011. These results inform our understanding of cetacean behavior and habitat use in this region and may aid in the development of conservation strategies suited to the dynamic conditions that drive cetacean distribution.

Long-term passive acoustic monitoring revealed seasonal and diel patterns of cetacean presence in the Istanbul Strait

2013 ◽  
Vol 94 (6) ◽  
pp. 1195-1202 ◽  
Author(s):  
Ayhan Dede ◽  
Ayaka Amaha Öztürk ◽  
Tomonari Akamatsu ◽  
Arda M. Tonay ◽  
Bayram Öztürk
Keyword(s):  
Monitoring System ◽  
Black Sea ◽  
Aegean Sea ◽  
Acoustic Monitoring ◽  
Pelagic Fish ◽  
The Black Sea ◽  
Common Dolphin ◽  
Passive Acoustic Monitoring ◽  
Cetacean Species ◽  
Passive Acoustic

The Istanbul Strait (Bosphorus) is a part of the Turkish Straits System, connecting the Aegean Sea and the Black Sea. There are three cetacean species in the Strait, namely the harbour porpoise (Phocoena phocoena), the common dolphin (Delphinus delphis), and the bottlenose dolphin (Tursiops truncatus). To monitor the presence of the cetaceans, a fixed stereo passive acoustic monitoring system (A-tag) was deployed in the middle of the Strait from July 2009 to September 2010. In total 26,814 click trains were detected. Presence, direction and inter-click intervals of phonating cetaceans were measured. Most click trains were detected during the night time. Diel presence pattern was prominent in March and April. In spring, the cetaceans were concentrated in one specific direction from the fixed monitoring system. In contrast, they were found in all directions for the rest of the year. Short range sonar (inter-click intervals (ICIs) less than 50 ms) was commonly detected in spring. During the rest of the year ICIs could reach up to 150 ms. All these findings suggest that they were feeding or socializing in spring and mostly travelling in the other seasons. It is well known that pelagic fish such as sprat and bluefish start their migration from the Aegean Sea to the Black Sea in spring. This study suggests that the cetaceans use the middle part of the Strait for feeding on the pelagic fish in spring when the fish migration has just started.

scholarly journals Noisy neighbors and reticent residents: Distinguishing resident from non-resident individuals to improve passive acoustic monitoring

2021 ◽  
pp. e01710
Author(s):  
Dana S. Reid ◽  
Connor M. Wood ◽  
Sheila A. Whitmore ◽  
William J. Berigan ◽  
John J. Keane ◽  
...  
Keyword(s):  
Acoustic Monitoring ◽  
Passive Acoustic Monitoring ◽  
Passive Acoustic
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