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

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 thorough performance tests are conducted in
any study utilizing APTs. The APTs tested here appear best suited for
studies in structurally simple ecosystems or for studying pelagic species.
In such situations, the data quality provided by the APTs is exceptionally
high.