Operational Plan for the Restoration of Diadromous Fishes to the ...

used Kenduskeag Stream as an example of a management reach downstream of all
dams. To model the effects of dams on salmon population viability we developed
management reaches that aggregate some of the finer-scale reaches described
above (Table 2). For each management reach we tallied the number of dams a
smolt or adult would have to pass, and then used fish passage efficiencies and
mortality data to estimate the cumulative effects of the dams on the population
dynamics.
Dam passage input data were derived from numerous sources:
Holbrook, 2007, assessed survival of smolts and smolt movement using ultrasonic
telemetry. Survival rates for mainstem dams were estimated. Both hatchery and
wild smolts were used in the study that provides the most recent and comprehensive
estimates of smolt survival at dams in the Penobscot. The study integrated survival
factors surrounding dams including effects of the dam itself, plus variables such as
transit times through reservoirs and increased opportunity of predation.
The ASAL model was used to estimate smolt survival at Mattaceunk Dam. Direct
estimates of smolt survival at this dam were not available. This result was presented
in a review of downstream fish passage in the Annual Report of the U.S. Atlantic
Salmon Assessment Committee Report No. 17 – 2004 Activities. This review
contained numerous FERC reports on fish passage and ASAL modeling results;
however, most of this work was superseded by Holbrook, 2007.
Adult Atlantic salmon upstream passage efficiencies were obtained from Fay, C., M.
Bartron, S. Craig, A. Hecht, J. Pruden, R. Saunders, T. Sheehan, and J. Trial.
2006. Status Review for Anadromous Atlantic Salmon (Salmo salar) in the United
States. Report to the National Marine Fisheries Service and U.S. Fish and Wildlife
Service. 294 pages. See this document for primary sources.
Additional adult upstream passage efficiencies were derived from Beland and
Gorsky, 2004 in Atlantic Salmon Freshwater Assessments and Research Semi-
Annual Project Report NOAA Grant NA17FL1157 Covering the period November 1,
2003 – April 30, 2004, Appendix A. Additional data from Gorsky, 2005, (Site Fidelity
and the Influence of Environmental Variables on Migratory Movements of Adult
Atlantic Salmon (Salmo salar L.) in the Penobscot River Basin, Maine Master’s
Thesis. University of Maine. 2005) was also used to augment the passage
efficiencies.
Where multiple estimates existed, we used the high and low estimates as the range,
and used the mean of these two values as the deterministic value. When both a
range and mean passage efficiency or survival were given, we used the data as
presented (Table 3). Although the data presented here represent a large body of
work, there are still important gaps in the data for Atlantic salmon passage. The
more recent PIT tag telemetry studies on adults and smolts tend to integrate
variables surrounding dams. This can make it difficult to interpret the effect of a dam
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