scholarly journals The use of a camera trap and acoustic survey design to ascertain the vocalization and breeding status of the highly elusive White-winged Flufftail, Sarothrura ayresi

2020 ◽  
Vol 15 (2) ◽  
Author(s):  
Robin B. Colyn ◽  
Alastair Campbell ◽  
Hanneline A. Smit-Robinson
Keyword(s):  
Survey Design ◽  
Camera Trap ◽  
Acoustic Survey ◽  
Breeding Status

scholarly journals Target strength measurement of Caroun croaker (Johnius sp.) and acoustic fish density estimation in Musi Estuary, South Sumatra

2021 ◽  
Vol 944 (1) ◽  
pp. 012008
Author(s):  
F Supriyadi ◽  
I Jaya ◽  
S Pujiyati ◽  
T Hestirianoto ◽  
Z Fahmi
Keyword(s):  
Survey Design ◽  
Economic Value ◽  
Acoustic Pulse ◽  
Target Strength ◽  
Estuarine Fish ◽  
Fish Length ◽  
Acoustic Survey ◽  
Strength Measurement ◽  
Fish Stocks ◽  
Length Relationship

Abstract Caroun Croaker ( Johnius sp.) is one of the dominant estuarine fish that has a reasonably high economic value. The target strength (TS) value measurement is essential in calculating the density of fish stocks using the hydroacoustic method. Target strength measurement of Caroun Croaker (Johnius sp.) and an acoustic survey in Musi Estuary Waters of South Sumatra Province was conducted in December 2019. The result of TS measurement will be used to estimate the acoustic density along the survey area. The TS measurement used the standard tethered method, tying placing the fish in a fixed cage, transmitting the acoustic pulse, and analyzing its return using the scientific acoustic instrument Biosonic DT-X 200 KHz. The fisheries acoustic survey was carried out in the area around the Musi estuary with a predetermined survey design. The results of the measurements have obtained the TS-length relationship, as TS= 20 LOG L-78.79 with determinant value of R2= 0.67 for fish length ranges from 18.1-23.3 cm, and an acoustic survey showed that the estimated stock density value was 286 kg/ha for the total surveyed area of 1.612 ha.

Relative rarity of small wild cats in the Brazilian Pantanal

Mammalia ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Fernando R. Tortato ◽  
Allison L. Devlin ◽  
Ricardo L. P. Boulhosa ◽  
Rafael Hoogesteijn
Keyword(s):  
Survey Design ◽  
Interspecific Interactions ◽  
Local Population ◽  
Camera Trap ◽  
Population Status ◽  
Leopardus Pardalis ◽  
Relative Rarity ◽  
Wild Cats ◽  
Brazilian Pantanal ◽  
Practical Implications

AbstractSmall wild cats (SWC) are naturally cryptic species. The current study presents occurrence information and capture-rates on four SWC species found in the Brazilian Pantanal. The most commonly recorded SWC by camera trap was Leopardus pardalis. Leopardus colocolo and Puma yagouaroundi were relatively rare, while Leopardus guttulus was not recorded in any survey year. We interpret our findings based on the potential competitive influences of L. pardalis and practical implications of camera trap survey design. We recommend that future studies should design camera trap grids with spacing appropriate for SWC to more directly address questions on local population status and interspecific interactions.

scholarly journals An adaptive, integrated “acoustic-trawl” survey design for Atlantic cod (Gadus morhua) with estimation of the acoustic and trawl dead zones

2005 ◽  
Vol 62 (1) ◽  
pp. 93-106 ◽  
Author(s):  
Ian H. McQuinn ◽  
Yvan Simard ◽  
Thomas W.F. Stroud ◽  
Jean-Louis Beaulieu ◽  
Stephen J. Walsh
Keyword(s):  
Gadus Morhua ◽  
Sampling Design ◽  
Atlantic Cod ◽  
Survey Design ◽  
Dead Zone ◽  
Total Biomass ◽  
Trawl Survey ◽  
Acoustic Survey ◽  
Night Time ◽  
Diel Vertical Migrations

Abstract The objectives of this study were to design an operationally efficient groundfish survey integrating both acoustic and trawl methodologies, to measure the changing vertical availability of cod to each method over 24 h and to compare cod-biomass estimates from the two methods within two experimental sub-regions. The two-phased sampling design involved (i) conducting an initial systematic acoustic survey to locate an area of high cod concentrations, (ii) using the acoustic-backscatter information to stratify the sub-regions into density strata for the allocation of trawl hauls, and (iii) conducting a second systematic acoustic survey at the same time as a random-stratified trawl survey. This protocol permitted the optimization of trawl sampling according to population density and the realization of simultaneous trawl and acoustic estimates for direct comparison. These cod showed extensive diel vertical migrations, which affected their availability to the trawl gear at night and the acoustic beam by day. An acoustic dead-zone correction was applied to the acoustic estimates, averaging 4–15% of the biomass for the night-time transects and 11–36% for the daytime transects. The detailed temporal acoustic monitoring of the vertical migrations permitted the quantification of the change in cod availability to the trawl gear. From 6% to 47% of cod were above the effective trawl height at night, while 0–10% of cod were in the “trawl dead zone” by day. Estimated cod densities were very similar between the two methods on a haul-by-haul basis after correcting each method for their respective inherent sampling biases. The total biomass estimates were also comparable between the two methods for one sub-region, although significantly higher from the trawl data for the other. The discrepancies were most likely a result of differences in the sampling density of the two methods.

scholarly journals The use of an adaptive acoustic-survey design to estimate the abundance of highly skewed fish populations

2009 ◽  
Vol 66 (6) ◽  
pp. 1349-1354 ◽  
Author(s):  
Alf Harbitz ◽  
Egil Ona ◽  
Michael Pennington
Keyword(s):  
Root Mean Square Error ◽  
Mean Square Error ◽  
Root Mean Square ◽  
Survey Design ◽  
Clupea Harengus ◽  
Fish Populations ◽  
North Coast ◽  
Acoustic Survey ◽  
Mean Square ◽  
Abundance Estimates

Abstract Harbitz, A., Ona, E., and Pennington, M. 2009. The use of an adaptive acoustic-survey design to estimate the abundance of highly skewed fish populations. – ICES Journal of Marine Science, 66: 1349–1354. The uncertainty (relative root-mean-square error) of abundance estimates based on a simple and easily implemented adaptive design for an acoustic survey is examined. The study is limited to surveys with parallel transects and independent observations with extremely skewed distributions. The adaptive approach defines a stratum for each conventional observation and how to take additional observations in that stratum when the acoustic density exceeds a predetermined threshold. The cost (sailing distance) of each added observation is about three times that of a conventional observation. This method was demonstrated using high-resolution transect data from a herring (Clupea harengus) acoustic survey conducted in 2006 off the north coast of Norway. The primary sampling unit for this winter survey was 5 nautical miles, and the usual distance between transects was 20 nautical miles. The results indicate that an adaptive survey design would substantially reduce the root-mean-square error of the abundance estimates compared with that of the conventional survey design.

Simulation modeling of a trawl-acoustic survey design for patchily distributed species

2012 ◽  
Vol 125-126 ◽  
pp. 289-299 ◽  
Author(s):  
Paul D. Spencer ◽  
Dana H. Hanselman ◽  
Denise R. McKelvey
Keyword(s):  
Simulation Modeling ◽  
Survey Design ◽  
Acoustic Survey

scholarly journals Assessing the Status of Wild Felids in a Highly-Disturbed Commercial Forest Reserve in Borneo and the Implications for Camera Trap Survey Design

PLoS ONE ◽  
2013 ◽  
Vol 8 (11) ◽  
pp. e77598 ◽  
Author(s):  
Oliver R. Wearn ◽  
J. Marcus Rowcliffe ◽  
Chris Carbone ◽  
Henry Bernard ◽  
Robert M. Ewers
Keyword(s):  
Survey Design ◽  
Camera Trap ◽  
Forest Reserve ◽  
Wild Felids ◽  
The Status ◽  
Commercial Forest

PERCEIVED EFFECTS OF STREET HAWKING ON THE WELL-BEING OF CHILDREN IN ANYIGBA, DEKINA LOCAL GOVERNMENT AREA OF KOGI STATE, NIGERIA

2018 ◽  
Vol 8 (1) ◽  
pp. 01-07
Author(s):  
Alfred Eboh
Keyword(s):  
Local Government ◽  
Survey Design ◽  
Sampling Technique ◽  
Well Being ◽  
Local Government Area ◽  
Negative Consequences ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Perceived Effects ◽  
The Government

Background: The hawking of wares by children has been a serious issue confronting the Nigerian society. Children hawk in some of the most horrible conditions conceivable, where they face a serious risk of injury, chronic illness, kidnapping, rape or death. Objective: The focus of this study was to assess the perceived effects of street hawking on the well-being of children in Anyigba, Dekina Local Government Area of Kogi State. Methods: The population of this study consists of parents of the street hawkers in Anyigba while cross-sectional survey design was used through the purposive sampling technique to choose the sample size of one hundred and sixty-two (162) respondents. The validated structured questionnaire and In-Depth Interviews (IDIs) served as the instruments for the data collection respectively. The hypotheses were tested using Chi-Square at a predetermined 0.05 level of significance. The quantitative data were analysed with the aid of the SPSS (version 20). Results: The results indicated among others that street hawking had significant social implications and physical consequences on children's moral behaviour as well as health status in the study area. Conclusion: The study, therefore, concluded that the government of Kogi State should carry out an enlightenment campaign through the media and religious institutions on the negative consequences of street hawking are recommended as panacea. Also, the child right act instrument and its implementation should be strengthened in order to curb street hawking in the study area.

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