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

Appendix A - Role of Hatchery Releases or Exogenous Stock Transfers in
Alosine Restoration
Authors: Fred Seavey (USFWS) and Gail Wippelhauser (MDMR)
1. Introduction
The State of Maine has identified a goal of rebuilding American shad, blueback
herring and alewife (collectively referred here as alosines) populations to the
Penobscot River (MDMR and MDIFW 2008). Here we consider whether the
Penobscot River alosine restoration should occur by natural recovery; by
supplementation using adult fish transfers and/or stocking of hatchery-reared
juveniles; and whether supplementation should use lower river stocks or exogenous
stocks. Fish transfers 18 and hatchery supplementation with fry or fingerlings 19 using
in-basin or out-of-basin (exogenous) sources of broodstock are common restoration
practices in Maine and elsewhere. These restoration methods are proposed for the
Penobscot River where alosines have been extirpated from a large portion of the
watershed or where remnant populations are currently believed to exist in small
numbers in the lower river (the first dam is just upstream of the head-of-tide) and its
tributaries.
No alosine genetic investigations are currently available for the Penobscot River or
potential Maine donor rivers to assist us in understanding how Maine’s alosine
populations may (or may not) be structured, but two studies are either currently
underway or planned in the near future. One focuses on American shad genetics
along the Atlantic Coast (P. Benson, personal communication, December 3, 2008)
and the other addresses alewife genetics in Maine (T. Willis, personal
communication, December 2, 2008). The results from these studies will be
considered once it is peer-reviewed and becomes available
This review makes a judgment as to the likelihood that Penobscot River alosine
populations may have a population structure by reviewing the literature addressing
alosine population structure, describing the current management experience, and
discussing the implications of each. It also provides an approach for the use of
exogenous stock transfer or hatchery supplementation for restoring extirpated
Penobscot River alosine stocks based on this information.
18
The movement, transfer and placement of gravid adults from a self-sustaining population to an area
with an extirpated or depressed population.
19
The collection of eggs from gravid adults that are then fertilized, reared and released to restore an
extirpated populations or supplement a depressed population.
PRFP Page 116