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

This task is implementing the integrated enhancement plan (Task 13.2.1) and the fry
stocking adaptive management plan (Task 13.2.5). Carefully documenting stocking
methods, environmental conditions, and product characteristics (e.g. stocking
density, release type, temperature flow, DI etc.) during stocking is required to allow
feedback to the adaptive management of fry.
13.2.10 Evaluate alternative fry stocking strategies/locations to increase smolt
production
Since stocking hatchery fry became one of the contemporary restoration strategies
for the Maine salmon program, the approach has been to scatter fry in the mainstem
of major tributaries to the Penobscot (e.g. Piscataquis, East Branch). While scatter
stocking is more labor intensive than point stocking, it was adopted to reduce
intraspecific competition. This strategy has produced high juvenile densities in some
but not all of the areas currently stocked. By maintaining past strategies in some
reaches, alternative strategies to increase juvenile production (parr and smolts)
using can be tested using a Before-After/Control-Impact (BACI) design. Alternative
strategies to test include, but may not be limited to: allocating a portion of fry stocked
in mainstem reaches to smaller sized streams; stocking vacant tributaries (not being
monitoring for natural re-colonization) in the lower sub watersheds where population
viability may be higher than in headwaters above dams; and varying fry stocking
densities annually at locations, to mimic natural spawning variability (e.g. high fall
water levels – more spawning likely to occur in tributaries and farther upstream). To
ensure effective assessment (Task 13.2.2), strategies will be segregated
geographically.
13.2.11 Develop a parr stocking adaptive management plan
The goal of the plan is to maximum the number of smolt reaching Penobscot Bay
from stocking parr (Appendix E). Parr are currently the by-product of the
accelerated one-year smolt program at GLNFH. Past decisions for the annual
allocations of GLNFH parr needs to be documented (Task 13.2.7). Future
allocations need to considered: location relative to past experience and modeled
population viability (Appendix B), potential productivity (Appendix C and Task
13.3.3), and stocking of other salmon life stages. The potential to stock 0+ parr
reared at ambient water temperatures also needs to be evaluated. Integrating smolt,
parr, and fry stocking includes stocking parr in waters where fry perform poorly (e.g.
wider rivers, high levels of predators/competitors) or where insufficient fry numbers
are available to stock, and segregating parr from smolt stocking. The plan should
allocate parr into reaches with sufficient quality habitat for the typical number of parr
produced by GLNFH to survive for 8 to 32 months in the fresh water environment.
Resulting parr densities will depend in part on the size or physiological state of the
fish when stocked. Current data on the proportion of the stocked parr that smolt the
following spring (P8) suggests that most GLNFH parr emigrate after only one winter
in the wild. In contrast, a large proportion of 0+ parr reared on ambient water at
CBNFH spend two winters in freshwater (P20). The plan needs to anticipate
changes in stocking strategy as more is learned about how size at stocking affects
the proportion of smolts emigrating the spring after stocking and as adult returns
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