scholarly journals Potential detection of illegal fishing by passive acoustic telemetry

2019 ◽  
Vol 7 (1) ◽  
Author(s):  
David M. Tickler ◽  
Aaron B. Carlisle ◽  
Taylor K. Chapple ◽  
David J. Curnick ◽  
Jonathan J. Dale ◽  
...  
2022 ◽  
Vol 8 ◽  
Author(s):  
Chantel Elston ◽  
Paul D. Cowley ◽  
Rainer G. von Brandis ◽  
James Lea

Abiotic factors often have a large influence on the habitat use of animals in shallow marine environments. Specifically, tides may alter the physical and biological characteristics of an ecosystem while changes in temperature can cause ectothermic species to behaviorally thermoregulate. Understanding the contextual and relative influences of these abiotic factors is important in prioritizing management plans, particularly for vulnerable faunal groups like stingrays. Passive acoustic telemetry was used to track the movements of 60 stingrays at a remote and environmentally heterogeneous atoll in Seychelles. This was to determine if habitat use varied over daily, diel and tidal cycles and to investigate the environmental drivers behind these potential temporal patterns. Individuals were detected in the atoll year-round, but the extent of their movement and use of multiple habitats increased in the warmer NW-monsoon season. Habitat use varied over the diel cycle, but was inconsistent between individuals. Temperature was also found to influence stingray movements, with individuals preferring the deeper and more thermally stable lagoon habitat when extreme (hot or cold) temperature events were observed on the flats. Habitat use also varied over the tidal cycle with stingrays spending a higher proportion of time in the lagoon during the lowest tides, when movement on the flats were constrained due to shallow waters. The interplay of tides and temperature, and how these varied across diel and daily scales, dynamically influenced stingray habitat use consistently between three species in an offshore atoll.


2012 ◽  
Vol 63 (4) ◽  
pp. 341 ◽  
Author(s):  
Hamish A. Campbell ◽  
Matthew Hewitt ◽  
Matthew E. Watts ◽  
Stirling Peverell ◽  
Craig E. Franklin

Patterns of movement in aquatic animals reflect ecologically important behaviours. Cyclical changes in the abiotic environment influence these movements, but when multiple processes occur simultaneously, identifying which is responsible for the observed movement can be complex. Here we used acoustic telemetry and signal processing to define the abiotic processes responsible for movement patterns in freshwater whiprays (Himantura dalyensis). Acoustic transmitters were implanted into the whiprays and their movements detected over 12 months by an array of passive acoustic receivers, deployed throughout 64 km of the Wenlock River, Qld, Australia. The time of an individual’s arrival and departure from each receiver detection field was used to estimate whipray location continuously throughout the study. This created a linear-movement-waveform for each whipray and signal processing revealed periodic components within the waveform. Correlation of movement periodograms with those from abiotic processes categorically illustrated that the diel cycle dominated the pattern of whipray movement during the wet season, whereas tidal and lunar cycles dominated during the dry season. The study methodology represents a valuable tool for objectively defining the relationship between abiotic processes and the movement patterns of free-ranging aquatic animals and is particularly expedient when periods of no detection exist within the animal location data.


2013 ◽  
Vol 24 (1) ◽  
pp. 199-218 ◽  
Author(s):  
S. T. Kessel ◽  
S. J. Cooke ◽  
M. R. Heupel ◽  
N. E. Hussey ◽  
C. A. Simpfendorfer ◽  
...  

PLoS ONE ◽  
2015 ◽  
Vol 10 (8) ◽  
pp. e0134002 ◽  
Author(s):  
Manuela Capello ◽  
Marianne Robert ◽  
Marc Soria ◽  
Gael Potin ◽  
David Itano ◽  
...  

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