Performance assessment of two whole-lake acoustic positional telemetry systems - is reality mining of free-ranging aquatic animals technologically possible?

• Published in: PLOS ONE
• Main Authors: Baktoft, Henrik, Zajicek, Petr, Klefoth, Thomas, Svendsen, Jon Christian, Jacobsen, Lene, Pedersen, Martin Wæver, Morla, David March, Skov, Christian, Nakayama, Shinnosuke, Arlinghaus, Robert
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2015
• Subjects: MULTIDISCIPLINARY; COD GADUS-MORHUA; BASS MICROPTERUS-SALMOIDES; JUVENILE ATLANTIC COD; LARGEMOUTH BASS; NATURAL-ENVIRONMENT; ACTIVITY PATTERNS; FISH; BEHAVIOR; TRACKING; BIOTELEMETRY; atlantic cod; Gadus morhua
• Online Access: https://orbit.dtu.dk/en/publications/012102e0-43fa-488f-8329-283ede84cf62; https://doi.org/10.1371/journal.pone.0126534; https://backend.orbit.dtu.dk/ws/files/110962494/Publishers_version.pdf; http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4441435/

Acoustic positional telemetry systems (APTs) represent a novel approach to study the behaviour of free ranging aquatic animals in the wild at unprecedented detail. System manufactures promise remarkably high temporal and spatial resolution. However, the performance of APTs has rarely been rigorously tested at the level of entire ecosystems. Moreover, the effect of habitat structure on system performance has only been poorly documented. Two APTs were deployed to cover two small lakes and a series of standardized stationary tests were conducted to assess system performance. Furthermore, a number of tow tests were conducted to simulate moving fish. Based on these data, we quantified system performance in terms of data yield, accuracy and precision as a function of structural complexity in relation to vegetation. Mean data yield of the two systems was 40%(Lake1) and 60%(Lake2). Average system accuracy (acc) and precision (prec) were Lake1: acc = 3.1 m, prec = 1.1 m; Lake2: acc = 1.0 m, prec = 0.2 m. System performance was negatively affected by structural complexity, i.e., open water habitats yielded far better performance than structurally complex vegetated habitats. Post-processing greatly improved data quality, and sub-meter accuracy and precision were, on average, regularly achieved in Lake2 but remained the exception in the larger and structurally more complex Lake1. Moving transmitters were tracked well by both systems. Whereas overestimation of moved distance is inevitable for stationary transmitters due to accumulation of small tracking errors, moving transmitters can result in both over-and underestimation of distances depending on circumstances. Both deployed APTs were capable of providing high resolution positional data at the scale of entire lakes and are suitable systems to mine the reality of free ranging fish in their natural environment. This opens important opportunities to advance several fields of study such as movement ecology and animal social networks in the wild. It is recommended that ...