Date of Award

3-12-2020

Publication Type

Master Thesis

Degree Name

M.Sc.

Department

Earth and Environmental Sciences

Keywords

Acoustic telemetry, Detection range, Movement, Predation, Spatial ecology

Supervisor

Aaron Fisk

Rights

info:eu-repo/semantics/openAccess

Abstract

Acoustic telemetry is a popular tool to study the movements of animals and has resulted in substantial ecological knowledge gain. To effectively carry out acoustic telemetry studies, many technical and biological considerations must be made. This thesis aimed to fill gaps in knowledge pertaining to two common considerations in passive acoustic telemetry studies, particularly in nearshore freshwater habitats: understanding the influence of macrophytes on the detection efficiency and range of acoustic telemetry equipment and identifying whether or not tagged animals have been consumed by an aquatic predator. Through the application of detection range testing and hydroacoustic surveys, it was revealed that distance and macrophyte biovolume interact to significantly influence the detection efficiency of acoustic transmitters, and this influence varied significantly based on the seasonal growth and senescence of macrophytes. The distance at which 50% of transmissions were successfully detected ranged from 5.5 m (± 139.6 S.D.) to 186.8 m (± 114.4 S.D.) and was significantly correlated to seasonal fluctuations in macrophyte biovolume. One of the first field applications of novel transmitters that identify predation events of tagged individuals indicated that 31.7% of tagged fish (n = 60) were apparently predated, and variable detection patterns were demonstrated using spatial metrices to examine the transmitter movements before and after the apparent predation event. The novel information presented in this thesis regarding the significant seasonal influence of macrophytes on detection efficiency and range and the application of acoustic transmitters that identify predation events in the wild will inform and improve future acoustic telemetry studies.

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