A Reliable Tag–Recapture Technique For Estimating Turbine Passage Survival: Application to Young-of-the-Year American Shad (Alosa sapidissima)

Abstract

A new technique (HI-Z Turb'N Tag, U.S. Patent No. 4,970,988) for estimating turbine passage survival was applied to juvenile American shad (Alosa sapidissima) under three operating conditions at a hydroelectric project. Fish are fitted externally with the Turb'N tag and introduced into turbine penstocks. The Turb'N Tag inflates after turbine passage and buoys fish to the surface for recapture and examination; after removal of tags, fish are held to assess long-term effects. Almost all (96%) test (299) and control (300) fish were recovered; average recovery time was less than 9 min. The overall short-term (1 h) survival of test fish, adjusted for control, was 97%; 24- and 48-h survivals were 98 and 94%, respectively. The 48-h survival of test fish was 98–100% for mixed flow and Kaplan turbines and 66.8% for the mixed flow unit in the vented mode. Acute control mortality was negligible (< 5%). Our technique offers several significant advantages over traditional net recapture methods: applicable to wide range of species and size; allows predetermination of statistically valid sample size, level of significance, and power of the test to determine need for mitigation measures; and estimation of cumulative effects of multiple turbine exposure.

EPRI-DOE Conference on Environmentally-Enhanced Hydropower Turbines: Technical Papers

“…The ERDC hydraulic models are constructed and tested based on Froude similitude. Biological studies to estimate direct and indirect mortality rates were conducted using Hi-Z Turb'N Tagged fish (Heisey et al 1992) and radio tracking (Skalski et. al.…”

“…may occur over an extended period or distance downstream after passage. Tailrace netting and the HI-Z Turb'N Tag (Heisey et al 1992) are the two principal methods that have been utilized to assess direct effects of turbine passage. Utilizing the HI-Z Tag capture method, studies can be conducted to determine causes of fish injury or mortality by direct capture.…”

“…The HI-Z Tag recapture technique has been used to assess different turbine types, spillways, sluiceways, fish bypass structures, and the characteristics and operations of these structures on the condition of passed fish (Heisey et al 1992(Heisey et al ,  2-166  2008Johnson et al 2003;Mathur et al 1994Mathur et al , 1999Mathur et al , 2000. The ability to examine the fish shortly after passing these structures provides information on the cause, rate, type and the severity of injuries.…”

Estimating Externalities of Hydro Fuel Cycles, Report 6

“…The seriousness of this issue depends on a number of factors, including the mitigative measures used to reduce turbine-passage mortality and the size, behavior, and species of fish susceptible to turbine entrainment. Large propeller-type turbines with large passageways and slow rotation speeds (such as might be installed at the Southeast Reference Site) may result in low mortalities (Heisey et al 1992). On the other hand, the small Pelton turbines used in many high-head hydroelectric facilities (e.g., the Northwest Reference Site) would cause 100 percent mortality of entrained fish.…”

Editorial: Time for green certification for all hydropower?

“…One example is balloon tagging that permits recovery of live fish after turbine passage to observe their physical condition. The balloon-tag recapture technique for live test fish 9 has been helpful and applied extensively for evaluating the direct injury and mortality rate of hydroturbine-passage, even though it does not permit assessment of the response of depth-acclimated fish to rapid decompression. Biotelemetry has become a valuable and common tool to study the behavior and survival of fish through river systems by remotely collecting information on fish movements and survival; passive integrated transponder (PIT) systems have been implemented at many large dams to monitor juvenile downstream fish passage and the return of adults.…”