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.

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 A Permanent Automated Real-Time Passive Acoustic Monitoring System for Bottlenose Dolphin Conservation in the Mediterranean Sea

PLoS ONE ◽  
2016 ◽  
Vol 11 (1) ◽  
pp. e0145362 ◽  
Author(s):  
Marco Brunoldi ◽  
Giorgio Bozzini ◽  
Alessandra Casale ◽  
Pietro Corvisiero ◽  
Daniele Grosso ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Real Time ◽  
Monitoring System ◽  
Bottlenose Dolphin ◽  
Acoustic Monitoring ◽  
Passive Acoustic Monitoring ◽  
The Mediterranean ◽  
Passive Acoustic

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.

scholarly journals Passive and active, predator and prey: using acoustics to study interactions between cetaceans and forage fish

2016 ◽  
Vol 73 (8) ◽  
pp. 2075-2084 ◽  
Author(s):  
Joshua M. Lawrence ◽  
Eric Armstrong ◽  
Jonathan Gordon ◽  
Susan Mærsk Lusseau ◽  
Paul G. Fernandes
Keyword(s):  
Moving Average ◽  
Management Strategies ◽  
Acoustic Monitoring ◽  
Pelagic Fish ◽  
Passive Acoustic Monitoring ◽  
Survey Techniques ◽  
Acoustic Methods ◽  
Passive Acoustic ◽  
Clyde Sea ◽  
Hydrophone Array

AbstractFisheries acoustics surveys provide platforms for deploying passive acoustic equipment to detect cetacean vocalizations. Passive acoustic methods are developing as viable alternatives to visual surveys, particularly for small, inconspicuous species such as the harbour porpoise (Phocoena phocoena). Passive acoustic monitoring using a towed hydrophone array was carried out during an acoustic survey of clupeids in the Clyde Sea and surrounding sea lochs to identify spatial relationships between porpoises and their prey. Methods were developed to process passive acoustic data, successfully identifying porpoise echolocation clicks while discriminating them from the transmitted 120-kHz echosounder pulse and its reflections. To date, this has been a confounding factor which has made these survey techniques potentially incompatible. The highest biomass of pelagic fish was detected in the northernmost parts of the survey region, as were the largest number of porpoises. A moving average was used to examine the scale of the relationships identified, and it was found that while porpoises show no significant preferences for pelagic prey numbers at the smallest scales, they do show significant avoidance of larger areas (5+ km) with very low pelagic fish biomass. This study demonstrates that high-frequency passive acoustic monitoring can be used effectively alongside multifrequency fisheries echosounder surveys to provide novel insights into the trophic interactions between these species, and that further work will hopefully prove useful in improving the efficacy of management strategies for harbour porpoises.

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