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

12.6.1 Proposal to investigate natural spawning performance of translocated
adult salmon
Natural spawning is fundamental to restoring self-sustaining populations, and few
management actions in the Penobscot promote natural spawning. Escapement to
headwater spawning habitat is compromised by upstream passage deficiencies and
other factors (e.g. imprinting). The reproductive success of adult sea-run salmon
transported directly into spawning habitat will be assessed. The effectiveness of
natural spawning relative to other enhancement techniques (e.g. fry stocking) will be
assessed (Task 12.1.8).
13.1.1 Literature review evaluating causes and remedies for poor performance
of hatchery fry relative to wild fry
Survival of hatchery reared juveniles is low relative to naturally reared fish. Although
the mechanism for post release mortality is often not well described, physical and
behavioral deficiencies in hatchery fish that may contribute to poor survival are well
documented. Emerging techniques in the science of reintroduction biology (e.g.,
environmental conditioning, life-skills training) offer high potential for improved
performance, often at minimal cost. Increasing performance of stocked fish may be
more cost effective than increasing production of stocked fish as a mechanism for
increasing adult returns. These techniques will be examined for applicability to the
Maine salmon program.
13.1.2 Literature review evaluating causes and remedies for poor performance
of hatchery smolts relative to wild smolts
Survival of hatchery-reared juveniles is low relative to naturally reared fish. Although
the mechanism for post release mortality is often not well described, physical and
behavioral deficiencies in hatchery fish which may contribute to poor survival are
well documented. Techniques in the science of reintroduction biology (e.g.
environmental conditioning, life-skills training, stocking at night) have the potential to
improve hatchery-reared smolt performance. Increasing performance of stocked fish
may be more cost effective than increasing production of stocked fish as a
mechanism for increasing adult returns. These techniques will be examined for
applicability to the Maine salmon program.
13.2.1 Develop an integrated stock enhancement program to optimize adult
Atlantic salmon returns
The objective is to consider when, where, and how each life stage is stocked in
order to maximize their accumulative contributions to adult returns and evaluate the
efficacy of stocking. It is critical that we are able to evaluate the contributions of
each hatchery product to juvenile production and adult returns. This will require a
stocking program that allows for the evaluation of individual stocking strategies
(Appendix D fry, GLNFH parr, adults, smolts). Future allocations of hatchery-reared
products should consider current data; modeled population viability (Appendix B),
potential productivity (Appendix C and Task 13.3.3), logistical constraints, and
stocking of other salmon life stages (Task 13.2.2). The plan should review existing
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