[Federal Register Volume 59, Number 223 (Monday, November 21, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-28682]
[[Page Unknown]]
[Federal Register: November 21, 1994]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
50 CFR Part 227
[Docket No. 941095-4295; I.D. 090894A]
Endangered and Threatened Species; Deer Creek Summer Steelhead
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice of determination.
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SUMMARY: NMFS has determined that Deer Creek summer steelhead in
Washington do not constitute a ``species'' under the Endangered Species
Act of 1973, as amended, (ESA) and, therefore, do not qualify for
listing under the ESA at this time. However, Deer Creek summer
steelhead are part of a larger evolutionarily significant unit (ESU)
that may warrant listing under the ESA, and for which a status review
is currently underway.
ADDRESSES: Environmental and Technical Services Division, NMFS,
Northwest Region, 911 NE. 11th Avenue, Suite 620, Portland, OR 97232.
FOR FURTHER INFORMATION CONTACT: Garth Griffin, Environmental and
Technical Services Division, 503/230-5430, or Marta Nammack, Endangered
Species Division, 301/713-2322.
SUPPLEMENTARY INFORMATION:
Petition Background
On September 21, 1993, NMFS received a petition from Washington
Trout to list indigenous, naturally-spawning Deer Creek summer
steelhead (Oncorhynchus mykiss) as an endangered species and to
designate critical habitat under the ESA. NMFS published a notice on
December 23, 1993 (58 FR 68108), that the petition presented
substantial information indicating that the listing may be warranted.
To ensure a comprehensive status review, NMFS solicited information and
data concerning the present and historic status of the Deer Creek
summer steelhead population and whether this population qualifies as a
``species'' under the ESA. NMFS also requested information on areas
that may qualify as critical habitat for Deer Creek summer steelhead.
NMFS also initiated an expanded status review for all coastal steelhead
in California, Oregon, and Washington. This status review was expanded
to include Idaho in response to a petition submitted by the Oregon
Natural Resources Council and 15 co-petitioners. NMFS initiated the
status review for steelhead throughout its range in the four states on
May 27, 1994 (59 FR 27527).
Biological Background
The NMFS Northwest Fisheries Science Center Biological Review Team
has conducted a status review and prepared an administrative report
summarizing the conclusions of the status review, ``Conclusions of the
Northwest Fisheries Science Center's Review of a Petition to List Deer
Creek Summer Steelhead (North Fork Stillaguamish River, Washington)
under the U.S. Endangered Species Act,'' which provides more detailed
information, discussion, and references. This report is available upon
request (see ADDRESSES) and is summarized below.
Deer Creek is a tributary of the North Fork Stillaguamish River in
Washington. The Deer Creek Watershed covers 177 km2 in the North
Cascade Mountains of Washington. Deer Creek and its steelhead fishery
have been the subject of many sporting journal articles and popular
literature. Logging in the Deer Creek Basin began in the 1920s. Timber
harvest activities accelerated in the early 1950s, and approximately 48
percent of the basin was clear-cut between 1952 and 1985. In 1984, a
large landslide, which remains active despite restoration efforts,
introduced a tremendous amount of sediment into Deer Creek. The 1984
landslide reduced viable spawning and rearing habitat for the summer
steelhead population, which was already in decline.
The name steelhead refers to the anadromous form of rainbow trout.
Recently, the scientific name for the biological species that includes
both steelhead and rainbow trout was changed from Salmo gairdneri to
Oncorhynchus mykiss. This change reflects a belief that all trouts from
western North America share a common lineage with Pacific salmon. The
present endemic distribution of steelhead extends from the Kamchatka
Peninsula, Asia, east and south, along the Pacific coast of North
America, to Malibu Creek in southern California.
Steelhead exhibit a wide variety of life history strategies. In
general, steelhead migrate to sea after spending 2 years in fresh water
and then spend 2 years in the ocean prior to returning to fresh water
to spawn. Deviations from this basic pattern are common. Some spawners
survive and return to the ocean for 1 or more years between spawning
migrations.
Steelhead exhibit two spawning migration strategies. ``Summer
steelhead'' enter fresh water between May and October, and begin their
spawning migration in a sexually immature state. After several months
in fresh water, summer steelhead mature and spawn. ``Winter steelhead''
enter fresh water between November and April with well developed
gonads. In drainages with sympatric populations of summer and winter
steelhead, there may or may not be temporal or spatial separation of
spawning.
Consideration as a ``Species'' Under the ESA
To qualify for listing as a threatened or endangered species, Deer
Creek summer steelhead would have to be a ``species'' under the ESA.
The ESA defines a ``species'' to include any ``distinct population
segment of any species of vertebrate *** which interbreeds when
mature.'' NMFS published a policy (56 FR 58612, November 20, 1991) on
how it will apply the ESA ``species'' definition to Pacific salmonid
species, including steelhead. This policy provides that a salmon
population will be considered distinct, and hence a species under the
ESA, if it represents an evolutionarily significant unit (ESU) of the
biological species. The population 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 biological
species. The first criterion, reproductive isolation, need not be
absolute, but must be strong enough to permit evolutionarily important
differences to accrue in different population units. The second
criterion is met if the population contributes substantially to the
ecological/genetic diversity of the species as a whole. Further
guidance on the application of this policy is contained in ``Pacific
salmon (Oncorhynchus spp.) and the Definition of Species under the
Endangered Species Act,'' which is available upon request (see
ADDRESSES).
Reproductive Isolation
In the Stillaguamish River Basin, three summer-run stocks and one
winter-run steelhead stock are recognized. Run timing is similar among
the Stillaguamish River Basin summer steelhead stocks; however, spawn
timing appears to be later for Deer Creek summer steelhead than for
other summer steelhead populations within the basin. Although run
timing differs between the Stillaguamish River summer and winter
steelhead stocks, there is substantial overlap in the time of spawning
of the two run types.
It was commonly thought that the high gradient reach of Deer Creek
between approximately river kilometer 2.4 and 7.2 comprised a
``cumulative velocity barrier'' to winter steelhead (C. Kramer, Area
Fish Biologist, Washington Department of Fish and Wildlife (WDFW),
pers. comm., May and July 1994). However, other evidence suggests that
this barrier may not be permanent, and recent flooding may have shifted
the Deer Creek bedload sufficiently to facilitate passage of winter
steelhead, thereby allowing for the possibility that summer steelhead
are not reproductively isolated from winter steelhead.
In general, genetic studies of coastal steelhead populations have
demonstrated that summer and winter steelhead from the same stream tend
to resemble one another genetically more than they resemble populations
with similar run timing from different drainages. These results suggest
that summer and winter steelhead do not represent two independent
monophyletic units. Allendorf (1975) reported that coastal summer
steelhead, including the Deer Creek population, were ``genetically
indistinguishable from the coastal winter run populations.'' A more
recent study (Phelps et al., in press) involving a larger set of gene
loci found some evidence of differentiation between summer and winter
steelhead in the Puget Sound region. The later study also found that
Deer Creek summer steelhead are ``relatively distinct'' from other
Puget Sound steelhead and show a higher degree of genetic similarity to
winter steelhead from the Stillaguamish and Skykomish rivers than to
other summer steelhead populations.
A variety of out-of-basin steelhead stocks have been released in
the Puget Sound area, and summer steelhead of Columbia River (Skamania
stock) origin have been released in the North Fork Stillaguamish River
since the 1960s (C. Kramer, WDFW, pers. comm., May and July 1994).
However, recent genetic data (Phelps et al. in press) found no evidence
that Deer Creek summer steelhead have been substantially affected by
these releases.
Ecological/Genetic Diversity
In Oregon, only three coastal basins have naturally-occurring
summer steelhead (Siletz, Umpqua, and Rogue basins). In contrast, all
major river basins in the North Puget Sound region (Nooksack/Samish,
Skagit, Stillaguamish, and Snohomish basins) are known to have
naturally-occurring summer steelhead. The discontinuous range of
coastal summer steelhead is consistent with the polyphyletic origin of
this life history inferred from genetic data. However, the Puget Sound
region is (or was) conducive to the development of the summer steelhead
life history, and within the Puget Sound region, Deer Creek is not
unique, or even unusual, in supporting summer-run steelhead.
The most common age structure for coastal steelhead from British
Columbia to California is 2/2 (2 years of freshwater residence followed
by 2 years in the ocean). Specific information about the age structure
of steelhead in the Puget Sound region is limited. Based on scale
samples from fish caught by anglers, Deer Creek summer steelhead are
reported to be primarily (95 percent) 2/1, with the remainder being 3/1
(C. Kramer, WDFW, pers. comm., May and July 1994). Other Puget Sound
steelhead, both summer- and winter-run, also have the 2/1 life history,
but sampling has not been sufficient to quantitatively describe age
structure in these populations. According to anecdotal information, the
adult size at spawning of other summer steelhead stocks (South Fork
Nooksack, Finney Creek, Sauk River, and Canyon Creek) is similar to
Deer Creek summer steelhead, and this suggests that other steelhead
populations in the Puget Sound region share the same adult body size
and other life history features with Deer Creek summer steelhead.
Determination
Deer Creek summer steelhead appear to be temporally and spatially
isolated from other populations of summer steelhead in the
Stillaguamish River Basin. Genetic data support the hypothesis that
Deer Creek summer steelhead are isolated from other Puget Sound
steelhead populations for which data are available. However, some
uncertainty remains regarding the relationship between Deer Creek
summer steelhead and nearby winter-run populations, both in the
Stillaguamish River and, perhaps, in upper Deer Creek. Despite this
uncertainty, NMFS has concluded, based on all available information,
that Deer Creek summer steelhead probably meet the first criterion to
be an ESU--that is, substantial reproductive isolation from other
conspecific populations.
Although the genetic data show that Deer Creek summer steelhead are
relatively distinct from other Puget Sound steelhead, the genetic
differences are not large in an absolute sense. Therefore, these
genetic differences provide little insight into the second ESU
criterion, contribution to ecological/genetic diversity of the species
as a whole. Deer Creek summer steelhead differ from many other coastal
steelhead populations in that most of the adults return after only 1
year in the ocean, but the limited available information indicates that
this is also observed in other Puget Sound steelhead populations. NMFS
found no other phenotypic or life history traits, or habitat features,
that distinguish the Deer Creek summer steelhead population from those
in adjacent areas. Therefore, NMFS concludes that Deer Creek summer
steelhead do not meet the second criterion to be considered an ESU and
are not, by themselves, a ``species'' under the ESA. Therefore, a
proposal to list Deer Creek summer steelhead under the ESA is not
warranted at this time.
However, Deer Creek summer steelhead are undoubtedly part of a
larger ESU that may warrant listing under the ESA, and NMFS will
identify the extent of this ESU during its current Washington, Oregon,
Idaho, and California steelhead status review (59 FR 27527, May 27,
1994). Detailed information provided in the petition for Deer Creek
steelhead will be considered during this expanded status review.
Dated: November 14, 1994.
Gary Matlock,
Program Management Officer, National Marine Fisheries Service.
[FR Doc. 94-28682 Filed 11-18-94; 8:45 am]
BILLING CODE 3510-22-F
