May 2, 2017
Journal Article

A Comparison of Metrics to Evaluate the Effects of Hydro-facility Passage Stressors on Fish


Hydropower is the most common form of renewable energy, and countries worldwide are considering expanding hydropower to new areas. One of the challenges of hydropower deployment is mitigation of the environmental impacts including water quality, habitat alterations, and ecosystem connectivity. For fish species that inhabit river systems with hydropower facilities, passage through the facility to access spawning and rearing habitats can be particularly challenging. Fish moving downstream through a hydro-facility can be exposed to a number of stressors (e.g., rapid decompression, shear forces, blade strike and collision, and turbulence), which can all affect fish survival in direct and indirect ways. Many studies have investigated the effects of hydro-turbine passage on fish; however, the comparability among studies is limited by variation in the metrics and biological endpoints used. Future studies investigating the effects of hydro-turbine passage should focus on using metrics and endpoints that are easily comparable. This review summarizes four categories of metrics that are used in fisheries research and have application to hydro-turbine passage (i.e., mortality, injury, molecular metrics, behavior) and evaluates them based on several criteria (i.e., resources needed, invasiveness, comparability among stressors and species, and diagnostic properties). Additionally, these comparisons are put into context of study setting (i.e., laboratory vs. field). Overall, injury and molecular metrics are ideal for studies in which there is a need to understand the mechanisms of effect, whereas behavior and mortality metrics provide information on the whole body response of the fish. The study setting strongly influences the comparability among studies. In laboratory-based studies, stressors can be controlled by both type and magnitude, allowing for easy comparisons among studies. In contrast, field studies expose fish to realistic passage environments but the comparability is limited. Based on these results, future studies, whether lab or field-based, should focus on metrics that relate to mortality for ease of comparison.

Revised: May 4, 2017 | Published: May 2, 2017


Colotelo A.H., A.E. Goldman, K.A. Wagner, R.S. Brown, Z. Deng, and M.C. Richmond. 2017. A Comparison of Metrics to Evaluate the Effects of Hydro-facility Passage Stressors on Fish. Environmental Reviews 25, no. 1:1-11. PNNL-SA-115486. doi:10.1139/er-2016-0006