Estimated detection distance of a baiji’s (Chinese river dolphin, Lipotes vexillifer) whistles using a passive acoustic survey method

2006 ◽  
Vol 120 (3) ◽  
pp. 1361-1365 ◽  
Author(s):  
Kexiong Wang ◽  
Ding Wang ◽  
Tomonari Akamatsu ◽  
Kaoru Fujita ◽  
Rika Shiraki
Keyword(s):  
Survey Method ◽  
Acoustic Survey ◽  
Detection Distance ◽  
River Dolphin ◽  
Passive Acoustic

scholarly journals Application of Acoustic Survey Method for Leakage Detection and Reduction in Water Distribution Network of Thessaloniki City, Greece

2020 ◽  
Vol 2 (1) ◽  
pp. 69
Author(s):  
Konstantinos Angelidis ◽  
Eleni Stavrotheodorou
Keyword(s):  
Water Supply ◽  
Water Loss ◽  
Water Distribution ◽  
Survey Methods ◽  
Distribution Network ◽  
Water Distribution Network ◽  
Survey Method ◽  
Acoustic Survey ◽  
Leakage Detection ◽  
Wide Range

Acoustic survey methods have been used in recent years in Greece due to rapid growth of technology for leakage detection in water distribution networks. The application of the latest methodologies and technologies allowed water authorities to improve the efficiency of their water supply networks. Thessaloniki’s water distribution network is an aging and inefficient one so the use of these methods in the last fifteen years has considerably improved the utility’s capability to reduce the losses of drinking water. The use of acoustic loggers on network fittings that record leakage noise in fixed time steps has a considerable effect in Thessaloniki’s water distribution network, which is characterized by a high level of complexity. A major challenge facing Thessaloniki Water Supply and Sewerage CO S.A. (EYATH S.A.) is how to deal with high levels of water loss, and acoustic survey methods are now seen as having an increasingly wide range of benefits, not only including environmental and water conservation benefits of reducing leak flow rate but also improving its performance in water loss management. The paper presents the implementation of the acoustic survey method for leakage detection and reduction in various field areas of Thessaloniki and the interconnected municipalities. Key parameters have been taken included, such as the complexity of water distribution network, the reliability of available mapping, the established zones with respective flow metering, and the existence of high background noise. Results are analyzed in order to examine the efficiency of the acoustic logging technology.

scholarly journals Passive acoustic monitoring effectively detects Northern Spotted Owls and Barred Owls over a range of forest conditions

The Condor ◽  
2020 ◽  
Vol 122 (3) ◽  
Author(s):  
Leila S Duchac ◽  
Damon B Lesmeister ◽  
Katie M Dugger ◽  
Zachary J Ruff ◽  
Raymond J Davis
Keyword(s):  
Acoustic Monitoring ◽  
Survey Method ◽  
Passive Acoustic Monitoring ◽  
Spotted Owl ◽  
Detection Probabilities ◽  
Spotted Owls ◽  
Northern Spotted Owl ◽  
Passive Acoustic ◽  
Northern Spotted Owls ◽  
Barred Owls

Abstract Passive acoustic monitoring using autonomous recording units (ARUs) is a fast-growing area of wildlife research especially for rare, cryptic species that vocalize. Northern Spotted Owl (Strix occidentalis caurina) populations have been monitored since the mid-1980s using mark–recapture methods. To evaluate an alternative survey method, we used ARUs to detect calls of Northern Spotted Owls and Barred Owls (S. varia), a congener that has expanded its range into the Pacific Northwest and threatens Northern Spotted Owl persistence. We set ARUs at 30 500-ha hexagons (150 ARU stations) with recent Northern Spotted Owl activity and high Barred Owl density within Northern Spotted Owl demographic study areas in Oregon and Washington, and set ARUs to record continuously each night from March to July, 2017. We reviewed spectrograms (visual representations of sound) and tagged target vocalizations to extract calls from ~160,000 hr of recordings. Even in a study area with low occupancy rates on historical territories (Washington’s Olympic Peninsula), the probability of detecting a Northern Spotted Owl when it was present in a hexagon exceeded 0.95 after 3 weeks of recording. Environmental noise, mainly from rain, wind, and streams, decreased detection probabilities for both species over all study areas. Using demographic information about known Northern Spotted Owls, we found that weekly detection probabilities of Northern Spotted Owls were higher when ARUs were closer to known nests and activity centers and when owls were paired, suggesting passive acoustic data alone could help locate Northern Spotted Owl pairs on the landscape. These results demonstrate that ARUs can effectively detect Northern Spotted Owls when they are present, even in a landscape with high Barred Owl density, thereby facilitating the use of passive, occupancy-based study designs to monitor Northern Spotted Owl populations.

scholarly journals Confirmation of right whales near a nineteenth-century whaling ground east of southern Greenland

2011 ◽  
Vol 7 (3) ◽  
pp. 411-413 ◽  
Author(s):  
David K. Mellinger ◽  
Sharon L. Nieukirk ◽  
Karolin Klinck ◽  
Holger Klinck ◽  
Robert P. Dziak ◽  
...  
Keyword(s):  
Nineteenth Century ◽  
North Atlantic ◽  
Eubalaena Glacialis ◽  
Acoustic Survey ◽  
Temporal Separation ◽  
Right Whale ◽  
Right Whales ◽  
North Atlantic Right Whales ◽  
Passive Acoustic

North Atlantic right whales ( Eubalaena glacialis ) were found in an important nineteenth century whaling area east of southern Greenland, from which they were once thought to have been extirpated. In 2007–2008, a 1-year passive acoustic survey was conducted at five sites in and near the ‘Cape Farewell Ground’, the former whaling ground. Over 2000 right whale calls were recorded at these sites, primarily during July–November. Most calls were northwest of the historic ground, suggesting a broader range in this region than previously known. Geographical and temporal separation of calls confirms use of this area by multiple animals.

Using Passive Acoustic Recording and Automated Call Identification to Survey Koalas in the Southern Forests of New South Wales

2020 ◽  
Vol 40 (3) ◽  
pp. 477-486
Author(s):  
B. Law ◽  
L. Gonsalves ◽  
R. Bilney ◽  
J. Peterie ◽  
R. Pietsch ◽  
...  
Keyword(s):  
Breeding Season ◽  
New South ◽  
New South Wales ◽  
Site Occupancy ◽  
Survey Method ◽  
Low Density ◽  
Phascolarctos Cinereus ◽  
South Wales ◽  
Acoustic Recording ◽  
Passive Acoustic

Cost-effective surveys of low density koala populations are challenging, but technological developments in the acoustics field offer great potential for landscape-scale surveys and monitoring. We assessed passive acoustic recording coupled with automated call identification as a survey method for koalas Phascolarctos cinereus . Surveys targeted areas of previously known koala activity based on scat surveys in southern forests of New South Wales where a low density of koalas is suspected. We set 24 Song Meters to record at night over a two week period (~3,696 hours) in the koala breeding season (October/November) in Murrah Flora Reserve. Recordings were scanned by a koala call recogniser and “matches” were manually verified. Across the 24 sites, 522 validated koala bellows were recorded at 21 sites (87.5 % detection rate). Three environmental variables had most influence on detection probability of koalas, including nightly rainfall (-ve), nightly temperature (-ve) and topographic position (lower on ridges). Calling activity peaked at midnight. Sustained site occupancy, at least in the short-term, was apparent as under optimal conditions (no rain) koalas were recorded, on average, for > 50 % of survey nights rather than for just a few nights. We suggest that only a modest survey effort (4–5 nights) in the breeding season, on nights with < 3 mm of rain, is required to achieve 90–95 % probability of koala call detection in an area of low koala density. Comparison with scat surveys at the same sites revealed that detection rates were more than three times greater with acoustic surveys. Technological advances will continue to provide improvements for wildlife survey, and perhaps most importantly, for collecting much needed long-term data to assess trends in occupancy or other population attributes over time.

Passive acoustic survey of Yangtze finless porpoises using a cargo ship as a moving platform

2011 ◽  
Vol 130 (4) ◽  
pp. 2285-2292 ◽  
Author(s):  
Lijun Dong ◽  
Ding Wang ◽  
Kexiong Wang ◽  
Songhai Li ◽  
Shouyue Dong ◽  
...  
Keyword(s):  
Acoustic Survey ◽  
Moving Platform ◽  
Passive Acoustic

Passive acoustic survey of bowhead whales in the Chukchi Sea.

2009 ◽  
Vol 125 (4) ◽  
pp. 2549-2549
Author(s):  
Julien Delarue ◽  
Marjo Laurinolli ◽  
Bruce Martin
Keyword(s):  
Chukchi Sea ◽  
Acoustic Survey ◽  
Bowhead Whales ◽  
Passive Acoustic

scholarly journals Passive acoustic monitoring of river dolphin (Inia geoffrensis and Sotalia fluviatilis) presence:

2021 ◽  
Author(s):  
Charles A Muirhead
Keyword(s):  
South America ◽  
Cost Effective ◽  
Acoustic Monitoring ◽  
Direct Result ◽  
Anthropogenic Activity ◽  
Passive Acoustic Monitoring ◽  
River Dolphin ◽  
Anthropogenic Development ◽  
Status Assessment ◽  
Passive Acoustic

All river dolphin species are in decline as a direct result of intensified anthropogenic activity along river systems. In South America, the size and geographical complexity of their range pose a challenge to status assessment. Passive acoustic monitoring offers a cost-effective, scalable, and readily standardized method for determining species distribution and can augment the spatiotemporal coverage of visual survey efforts currently underway. A passive acoustic survey of dolphin presence was conducted in two areas of the Amazon River subject to different degrees of human use; the inland port city Iquitos and the Pacaya-Samiria National Reserve, in Peru. Surveys were based on acoustic detection of biosonar activity. Recorders were distributed at 17 sites along 61 linear km of river habitat for durations of 46 to 148 h. Dolphin presence was 45% lower near the city than in the reserve. This study demonstrates the efficacy of acoustic monitoring as a method for testing dolphin redistribution and/or decline hypotheses in the context of anthropogenic development. The methods are applicable to continuous future monitoring and status assessment of river dolphins in South America as well as in Asia.

Development of a Rapid Survey Method of Sampling and Analysis for Asbestos in Ambient Air

1972 ◽  
Vol 30 ◽  
pp. 630-631 ◽  
Author(s):  
R. E. Heffelfinger ◽  
C. W. Melton ◽  
D. L. Kiefer ◽  
W. M. Henry ◽  
R. J. Thompson
Keyword(s):  
Neutron Activation ◽  
Ambient Air ◽  
Survey Method ◽  
Potential Hazard ◽  
Transmission Microscopy ◽  
Comparative Analyses ◽  
Asbestos Fibers ◽  
Controlled Conditions ◽  
Unequivocal Identification ◽  
Identification And Quantification

A methodology has been developed and demonstrated which is capable of determining total amounts of asbestos fibers and fibrils in air ranging from as low as fractional nanograms per cubic meter (ng/m3) of air to several micrograms/m3. The method involves the collection of samples on an absolute filter and provides an unequivocal identification and quantification of the total asbestos contents including fibrils in the collected samples.The developed method depends on the trituration under controlled conditions to reduce the fibers to fibrils, separation of the asbestos fibrils from other collected air particulates (beneficiation), and the use of transmission microscopy for identification and quantification. Its validity has been tested by comparative analyses by neutron activation techniques. It can supply the data needed to set emissions criteria and to serve as a basis for assessing the potential hazard for asbestos pollution to the populace.

Sign in / Sign up

Export Citation Format

Share Document