Petition to List Lynn Canal Pacific Herring under the Endangered ...

III. QUALIFICATION OF LYNN CANAL HERRING AS A DISTINCT
POPULATION SEGMENT UNDER THE ENDANGERED SPECIES ACT
The term “species” is defined broadly under the ESA to include “any subspecies
of fish or wildlife or plants and any distinct population segment of any species of
vertebrate fish or wildlife which interbreeds when mature.” 16 U.S.C. § 1532 (16).
The ESA does not define the meaning of term “distinct population segment.”
A. The USFWS-NMFS Distinct Population Segment (DPS)
Policy
NMFS and USFWS published a policy to define a “distinct population segment”
for the purposes of listing, delisting, and reclassifying species under the ESA (USFWS-
NMFS 1996). The DPS Policy identified two elements that must be considered when
making DPS determinations:
1) The discreteness of the population segment in relation to the remainder of the
species (or subspecies) to which it belongs; and
2) The significance of the population segment to the remainder of the species (or
subspecies) to which it belongs.
(USFWS-NMFS 1996). To be considered a DPS, the population must be both “discrete”
and “significant.” Once a population has satisfied the DPS Policy, the population
segment's conservation status in relation to the standards for listing a species under the
ESA is then evaluated (USFWS-NMFS 1996). The following sections analyze the Lynn
Canal Herring population under the DPS Policy. Section III evaluates the endangered
status of the Lynn Canal Herring in the context of the five statutory listing factors.
1. Cherry Point Pacific Herring DPS Determination
NMFS analyzed the Puget Sound and Georgia Basin populations of Pacific
Herring for ESA listing in 2001 and 2005 (Stout et al. 2001, NMFS 2005b). These
analyses support the delineation of Lynn Canal Herring as a DPS because NMFS
dismissed a larger, hypothetical DPS covering all of the eastern North Pacific. Rather
than defining an expansive DPS, NMFS carved out the Georgia Basin DPS of Pacific
Herring and therefore impliedly determined that several DPSs of Pacific Herring exist on
the west coast of North America.
Specifically, in 2001, NMFS described the expansive, hypothetical Pacific Herring DPS
as follows:
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