Telemetry Techniques: A User Guide for Fisheries Research

Section 9.1: Time-to-Event Analysis as a Framework for Quantifying Fish Passage Performance

Theodore Castro-Santos and Russell W. Perry

doi: https://doi.org/10.47886/9781934874264.ch18

The ability to monitor movements of animals using radio- and acoustic-telemetry has made it possible to observe continuous behavioral processes that determine key life history events. In this way telemetry offers similar improvements over mark-and-recapture methods as cinematography does over still photography. Imagine trying to reconstruct an entire movie from a series of 10 frames, or even 100; and compare that with watching a feature-length film. Clearly, the film provides a far more complete representation of the script. In the same way, collecting continuous records of free-ranging animals presents researchers with an opportunity to improve understanding of the causes and contexts of the movements of tagged individuals.

Researchers are also presented with a challenge: how to quantify continuous observations in ways that have biological relevance? Specifically, there is a need for a theoretical framework from which models and hypotheses can be developed that identify causal mechanisms underlying key behaviors and life history events. The purpose of this Section and the next (Section 9.2) is to demonstrate how telemetry studies can be designed and their data analyzed to optimize understanding of those causal mechanisms by taking full advantage of the temporal and spatial information that telemetry provides.

One of the most important behavioral applications of telemetry has been to study the passage of diadromous fishes past hydroelectric dams. In the United States, government agencies and utilities spend >$80,000,000 annually building and evaluating structures designed to improve survival and expedite passage of migratory fish. Various forms of acoustic-, and radio-telemetry (including passive integrated transponder (PIT) telemetry), are the primary tools used to evaluate the performance of these structures, and the combination of pressing concerns with significant funding has produced important advances in telemetry technology. Because of the importance of fish passage questions to telemetry technology, the methods described in this paper will be cast in this context. Readers should be aware, however, that the same concepts and methods have a much broader relevance, and analogous situations exist throughout the behavioral sciences (Allison 1995; Anderson et al. 2005; Williams et al. 2001).