scholarly journals Marine mammal tracks from two-hydrophone acoustic recordings made with a glider

2016 ◽  
Author(s):  
Elizabeth T. Küsel ◽  
Tessa Munoz ◽  
Martin Siderius ◽  
David K. Mellinger ◽  
Sara Heimlich
Keyword(s):  
Population Density ◽  
Density Estimation ◽  
Marine Mammal ◽  
Animal Movement ◽  
Sperm Whale ◽  
Western Coast ◽  
Physeter Macrocephalus ◽  
Acoustic Data ◽  
Acoustic Recording ◽  
Voice Recorder

Abstract. A multinational oceanographic and acoustic sea experiment was carried out in the summer of 2014 off the western coast of the island of Sardinia, Mediterranean Sea. During this experiment, an underwater glider was evaluated as a potential tool for recording marine mammal sounds for population density estimation studies. To this end, an acoustic recording system was also tested, comprising two hydrophones connected to an off-the-shelf voice recorder installed inside the glider. Analysis of the recorded acoustic data by a human analyst indicated the presence of sperm whale (Physeter macrocephalus) regular clicks as well as dolphin clicks and whistles. Further analysis of the data consisted in cross-correlating clicks recorded on both data channels for the estimation of the direction (bearing) of clicks, and realization of animal tracks. Insights from this bearing tracking analysis is expected to aid in population density estimation studies by providing further information on animal movement and location.

scholarly journals Marine mammal tracks from two-hydrophone acoustic recordings made with a glider

Ocean Science ◽  
2017 ◽  
Vol 13 (2) ◽  
pp. 273-288 ◽  
Author(s):  
Elizabeth T. Küsel ◽  
Tessa Munoz ◽  
Martin Siderius ◽  
David K. Mellinger ◽  
Sara Heimlich
Keyword(s):  
Population Density ◽  
Density Estimation ◽  
Marine Mammal ◽  
Sperm Whale ◽  
Western Coast ◽  
Physeter Macrocephalus ◽  
Digital Recorder ◽  
Acoustic Recording ◽  
Potential Tool

Abstract. A multinational oceanographic and acoustic sea experiment was carried out in the summer of 2014 off the western coast of the island of Sardinia, Mediterranean Sea. During this experiment, an underwater glider fitted with two hydrophones was evaluated as a potential tool for marine mammal population density estimation studies. An acoustic recording system was also tested, comprising an inexpensive, off-the-shelf digital recorder installed inside the glider. Detection and classification of sounds produced by whales and dolphins, and sometimes tracking and localization, are inherent components of population density estimation from passive acoustics recordings. In this work we discuss the equipment used as well as analysis of the data obtained, including detection and estimation of bearing angles. A human analyst identified the presence of sperm whale (Physeter macrocephalus) regular clicks as well as dolphin clicks and whistles. Cross-correlating clicks recorded on both data channels allowed for the estimation of the direction (bearing) of clicks, and realization of animal tracks. Insights from this bearing tracking analysis can aid in population density estimation studies by providing further information (bearings), which can improve estimates.

scholarly journals Testing a passive deterrent on longlines to reduce sperm whale depredation in the Gulf of Alaska

2015 ◽  
Vol 72 (5) ◽  
pp. 1667-1672 ◽  
Author(s):  
Victoria O'Connell ◽  
Janice Straley ◽  
Joe Liddle ◽  
Lauren Wild ◽  
Linda Behnken ◽  
...  
Keyword(s):  
Sperm Whale ◽  
Gulf Of Alaska ◽  
Primary Objective ◽  
Collaborative Effort ◽  
Physeter Macrocephalus ◽  
Anoplopoma Fimbria ◽  
Acoustic Data ◽  
The Individual ◽  
And Control ◽  
Individual Fishing Quota

Abstract In Alaska, sperm whale (Physeter macrocephalus) depredation on longline sets has increased since implementation of the Individual Fishing Quota programme in 1995. A collaborative effort (SEASWAP) between longliners, scientists, and managers has undertaken research to evaluate this depredation with a primary objective to develop and test a passive deterrent that would reduce depredation without reducing catch rate of sablefish (Anoplopoma fimbria). Commercial longliners, fishing for their own sablefish quotas during the regular season, deployed beaded gear (25 mm lucite beads attached to gangions) with control gear and set recorders to collect acoustic data. Beaded and control gear were randomly assigned by skate quad (672 hooks) with 5 quads in each longline set. Acoustic recorders were used to document sperm whale creak–pause events, representative of depredation of the longline gear. Although there were more sablefish per skate quad on the beaded gear and there was a decrease in depredation events on the beaded gear compared with the control, neither effect was significant (p = 0.205 and 0.364, respectively). The SEASWAP project is testing other deterrent strategies including gear modifications and the establishment of a sighting network to improve avoidance.

scholarly journals Estimating the density of a small population of leopards (Panthera pardus) in central Iran using multi-session photographic‐sampling data

2021 ◽  
Author(s):  
Mohammad S. Farhadinia ◽  
Pouyan Behnoud ◽  
Kaveh Hobeali ◽  
Seyed Jalal Mousavi ◽  
Fatemeh Hosseini-Zavarei ◽  
...  
Keyword(s):  
Population Density ◽  
Density Estimation ◽  
Animal Movement ◽  
Small Population ◽  
Central Iran ◽  
Large Carnivores ◽  
Panthera Pardus ◽  
Demographic Stochasticity ◽  
Density Estimates ◽  
Capture Recapture

AbstractWest Asian drylands host a number of threatened large carnivores, including the leopard (Panthera pardus) which is limited generally to areas with low primary productivity. While conservation efforts have focused on these areas for several decades, reliable population density estimates are missing for many of them. Spatially explicit capture–recapture (SECR) methodology is a widely accepted population density estimation tool to monitor populations of large carnivores and it incorporates animal movement in the statistical estimation process. We employed multi-session maximum-likelihood SECR modeling to estimate the density of a small population of leopard in a mountainous environment surrounded by deserts in central Iran. During 6724 camera trap nights, we detected 8 and 5 independent leopards in 2012 and 2016 sessions, respectively. The top-performing model produced density estimates of 1.6 (95% CI = 0.9–2.9) and 1.0 (95% CI = 0.6–1.6) independent leopards/100 km2 in 2012 and 2016, respectively. Both sex and season had substantial effects on spatial scale (σ), with larger movements recorded for males, and during winter. The estimates from our density estimation exercise represent some of the lowest densities across the leopard global range and strengthen the notion that arid habitats support low densities of the species. These small populations are vulnerable to demographic stochasticity, and monitoring temporal changes in their population density and composition is a critical tool in assisting conservation managers to better understand their population performance.

scholarly journals Beached bachelors: An extensive study on the largest recorded sperm whale Physeter macrocephalus mortality event in the North Sea

PLoS ONE ◽  
2018 ◽  
Vol 13 (8) ◽  
pp. e0201221 ◽  
Author(s):  
Lonneke L. IJsseldijk ◽  
Abbo van Neer ◽  
Rob Deaville ◽  
Lineke Begeman ◽  
Marco van de Bildt ◽  
...  
Keyword(s):  
North Sea ◽  
Sperm Whale ◽  
Extensive Study ◽  
Physeter Macrocephalus ◽  
Mortality Event ◽  
The North ◽  
The North Sea

Urban population density estimation based on spatio‐temporal trajectories

2020 ◽  
Vol 32 (14) ◽  
Author(s):  
Fei Xue ◽  
Yang Cao ◽  
Zhiming Ding ◽  
Hengliang Tang ◽  
Xi Yang ◽  
...  
Keyword(s):  
Population Density ◽  
Density Estimation ◽  
Urban Population ◽  
Spatio Temporal

Coinfection and Vertical Transmission of Brucella and Morbillivirus in a Neonatal Sperm Whale (Physeter macrocephalus) in Hawaii, USA

2015 ◽  
Vol 51 (1) ◽  
pp. 227-232 ◽  
Author(s):  
Kristi L. West ◽  
Gregg Levine ◽  
Jessica Jacob ◽  
Brenda Jensen ◽  
Susan Sanchez ◽  
...  
Keyword(s):  
Vertical Transmission ◽  
Sperm Whale ◽  
Physeter Macrocephalus
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