[Federal Register Volume 59, Number 244 (Wednesday, December 21, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-31370]
[[Page Unknown]]
[Federal Register: December 21, 1994]
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Part VI
Department of the Interior
Fish and Wildlife Service
Department of Commerce
National Oceanic and Atmospheric Administration
_______________________________________________________________________
Draft Policy Regarding the Recognition of Distinct Vertebrate
Population Segments Under the Endangered Species Act; Notice
DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
Draft Policy Regarding the Recognition of Distinct Vertebrate
Population Segments Under the Endangered Species Act; Request for
Public Comment
AGENCIES: Fish and Wildlife Service, Interior; National Marine
Fisheries Service, Commerce.
ACTION: Notice of draft policy; request for public comment.
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SUMMARY: The Fish and Wildlife Service and the National Marine
Fisheries Service (Services) propose to adopt a policy to clarify their
interpretation of the phrase ``distinct population segment of any
species of vertebrate fish or wildlife'' for the purposes of listing,
delisting, and reclassifying species under the Endangered Species Act
of 1973, as amended (16 U.S.C. 1531 et seq.) (Act). The Services seek
public comment on this draft statement of policy.
DATES: Comments from all interested parties must be received by
February 21, 1995, in order to be considered in the final decision on
this draft.
ADDRESSES: Comments and materials concerning this draft policy should
be sent to Chief, Division of Endangered Species, U.S. Fish and
Wildlife Service, ARLSQ-452, Washington, D.C. 20240 (telephone 703/358-
2105). Comments and materials received will be available for public
inspection, by appointment, during normal business hours in Room 452,
Arlington Square Building, 4401 North Fairfax Drive, Arlington,
Virginia.
FOR FURTHER INFORMATION CONTACT: Robert G. Ruesink, acting Chief,
Division of Endangered Species, U.S. Fish and Wildlife Service at the
above address (703/358-2171), or Russell Bellmer, Chief, Endangered
Species Division, National Marine Fisheries Service, 1335 East-West
Highway, Silver Spring, Maryland 20910 (301/713-2322).
SUPPLEMENTARY INFORMATION:
Background
The Endangered Species Act of 1973, as amended (16 U.S.C. 1531 et
seq.) (Act) requires the Secretary of the Interior or the Secretary of
Commerce (depending on jurisdiction) to determine whether species are
endangered or threatened. In defining ``species,'' the Act as
originally passed included, ``* * * any subspecies of fish or wildlife
or plants and any other group of fish or wildlife of the same species
or smaller taxa in common spatial arrangement that interbreed when
mature.'' In 1978, the Act was amended so that the definition read ``*
* * 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.'' This change restricted application of this
portion of the definition to vertebrates. The authority to list a
``species'' as endangered or threatened is thus not restricted to
species as recognized in formal taxonomic terms, but extends to
subspecies, and for vertebrate taxa, to distinct population segments.
Because the Secretary must ``* * * determine whether any species is
an endangered species or a threatened species'' (section 4(a)(1)), it
is important that the term ``distinct population segment'' be
interpreted in a clear and consistent fashion. Furthermore, Congress
has instructed the Secretary to exercise this authority with regard to
distinct population segments ``* * * sparingly and only when the
biological evidence indicates that such action is warranted.'' (Senate
Report 151, 96th Congress, 1st Session). The Services have used this
authority relatively rarely; of nearly 300 native vertebrate species
listed under the Act, only about 20 are given separate status as
distinct population segments.
It is important in light of the Act's requirement to use the best
available scientific information in determining the status of species
that this interpretation follow sound biological principles. Any
interpretation adopted should also be aimed at carrying out the
purposes of the Act (i.e., ``* * * to provide a means whereby the
ecosystems upon which endangered species and threatened species depend
may be conserved, to provide a program for the conservation of such
endangered species and threatened species, and to take such steps as
may be appropriate to achieve the purposes of the treaties and
conventions set forth in subsection (a) of this section'' (section
2(b)).
Available scientific information provides little specific
enlightenment in interpreting the phrase ``distinct population
segment.'' This term is not commonly used in scientific discourse,
although ``population'' is an important term in a variety of contexts.
For instance, a population may be circumscribed by a set of
experimental conditions, or it may approximate an ideal natural group
of organisms with approximately equal breeding opportunities among its
members, or it may refer to a loosely bounded, regionally distributed
collection of organisms. In all cases, the organisms in a population
are members of a single species.
The National Marine Fisheries Service (NMFS) has developed a Policy
on the Definition of Species under the Endangered Species Act (56 FR
58612-58618; November 20, 1991). The policy applies only to species of
salmonids native to the Pacific Ocean. Under this policy, a stock of
Pacific salmon is considered a distinct population segment if it
represents an evolutionarily significant unit (ESU) of a biological
species. A stock must satisfy two criteria to be considered an ESU:
(1) It must be substantially reproductively isolated from other
conspecific population units; and
(2) It must represent an important component in the evolutionary
legacy of the species.
This document proposes an interpretation of the term ``distinct
population segment'' for the purposes of listing, delisting, and
reclassifying vertebrates by the U.S. Fish and Wildlife Service and
NMFS. It is consistent with the policy on Pacific salmon, but more
broadly applicable.
The following principles would, if adopted, guide the Services'
listing, delisting and reclassification of distinct population segments
of vertebrate species. Any proposed or final rule affecting status
determination for a distinct population segment would clearly analyze
the action in light of these guiding principles.
Policy
Three elements would be considered in a decision regarding the
status of a possible distinct population segment as endangered or
threatened under the Act. These would be applied similarly for addition
to the lists, reclassification, and removal from the lists:
1. Discreteness of the population segment in relation to the
remainder of the species to which it belongs;
2. The significance of the population segment to the species to
which it belongs; and
3. The population segment's conservation status in relation to the
Act's standards for listing (i.e., is the population segment, when
treated as if it were a species, endangered or threatened?).
Discreteness: A population segment of a vertebrate species may be
considered discrete if it satisfies either one of the following
criteria:
1. It is markedly separated from other populations of the same
taxon as a consequence of physical, physiological, ecological, or
behavioral factors. Quantitative measures of genetic or morphological
discontinuity may provide evidence of this separation.
2. It is delimited by international governmental boundaries within
which differences in control of exploitation, management of habitat,
conservation status, or regulatory mechanisms exist that are
significant in light of section 4(a)(1)(D) of the Act.
Significance: If a population segment satisfies one or more of the
above criteria for discreteness, its biological and ecological
significance will then be considered in light of Congressional guidance
that the authority to list distinct population segments be used ``* * *
sparingly'' while encouraging the conservation of genetic diversity. In
carrying out this examination, the Services will consider available
scientific evidence of the discrete population segment's importance to
the taxon to which it belongs. This consideration may include, but is
not limited to, the following:
1. Persistence of the discrete population segment in an ecological
setting unusual or unique for the taxon,
2. Evidence that loss of the discrete population segment would
result in a significant gap in the range of a taxon,
3. Evidence that the discrete population segment represents the
only surviving natural occurrence of a taxon that may be more abundant
as an introduced population outside its historic range, or
4. Evidence that the discrete population segment differs markedly
from other populations of the species in its genetic characteristics.
Because precise circumstances are likely to vary considerably from
case to case, it is not possible to describe prospectively all the
classes of information that might bear on the biological and ecological
importance of a discrete population segment.
Status: If a population segment is discrete and significant (i.e.,
it is a distinct population segment) its evaluation for endangered or
threatened status will be based on the Act's definitions of those terms
and a review of the factors enumerated in section 4(a). It may be
appropriate to assign different classifications to different distinct
population segments of the same vertebrate taxon.
Relationship to Other Activities
The Fish and Wildlife Service's Listing and Recovery Priority
Guidelines (48 FR 43098; September 21, 1983) generally afford
``distinct population segments'' the same consideration as subspecies,
but when a subspecies and a distinct population segment have the same
numerical priority, the subspecies receives higher priority for
listing. The Services will continue to generally accord subspecies
higher listing priority than distinct population segments.
Any distinct population segment of a vertebrate taxon that was
listed prior to implementation of this policy will be evaluated on a
case-by-case basis as recommendations are made to change the listing
status for that distinct population segment. The appropriate
application of the policy will also be considered in the 5-year reviews
of the status of listed species required by section 4(c)(2) of the Act.
Effects of Policy
This draft policy would, if adopted, guide the evaluation of
distinct vertebrate population segments for the purposes of listing,
delisting, and reclassifying under the Act. The only direct effect of
any policy would be to accept or reject population segments for these
purposes. More uniform treatment of distinct population segments would
allow the Services, various other government agencies, private
individuals and organizations, and other interested or concerned
parties to better judge and concentrate their efforts toward the
conservation of biological resources at risk of extinction.
Listing, delisting, or reclassifying distinct vertebrate population
segments may allow the Services to protect and conserve species and the
ecosystems upon which they depend before large-scale decline occurs
that would necessitate listing a species or subspecies throughout its
entire range. This would allow protection and recovery of declining
organisms in a more timely and less costly manner, and on a smaller
scale than the more costly and extensive efforts that might be needed
to recover an entire species or subspecies. The Services' ability to
address local issues (without the need to list, recover, and consult
rangewide) would result in a more effective program.
Public Comments Solicited
The Services intend that a final decision on this draft policy on
distinct population segments of vertebrates take advantage of
information and recommendations from all interested parties. Therefore,
comments or suggestions from the public, other concerned governmental
agencies, the scientific community, industry, or any other interested
party concerning this draft policy are hereby solicited. Particularly
sought are comments on the following topics:
(1) The utility of the draft policy in carrying out the purposes of
the Act,
(2) Scientific evidence bearing on the appropriateness of the
concept of distinct population segments, or
(3) The relationship between the draft policy and the NMFS policy
regarding pacific salmon.
The final decision on this draft policy will take into
consideration the comments and any additional information received by
the Services, and such communications may lead to a decision that
differs from this draft. The Services' decision will be published for
public information.
Author/Editor
The editors of this draft policy are Dr. John J. Fay of the Fish
and Wildlife Service's Division of Endangered Species, 452 ARLSQ,
Washington, D.C. 20240 (703/358-2105) and Marta Nammack of the National
Marine Fisheries Service's Endangered Species Division, 1335 East-West
Highway, Silver Spring, Maryland 20910 (301/713-2322).
Authority
The authority for this action is the Endangered Species Act of
1973, as amended (16 U.S.C. 1531 et seq.).
Dated: August 5, 1994.
Mollie H. Beattie,
Director, Fish and Wildlife Service.
Dated: September 27, 1994
Nancy Foster,
Deputy Assistant Administrator for Fisheries National Marine Fisheries
Service.
[FR Doc. 94-31370 Filed 12-20-94; 8:45 am]
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