- Executive Summary
- West Coast Steelhead ESUs
- Coastal Steelhead ESUs
- Inland Steelhead ESUs
- Acknowledgments
- Introduction
- Scope and Intent of the Present
Document
- Key Questions in ESA
Evaluations
- The "Species" Question
- The "Extinction Risk"
Question
- Artificial Propagation
- Summary of the West Coast
Steelhead Petition
- Petitioners' "Definition of Species
and Application to Steelhead Trout"
- Summer steelhead
- A- and B-run
steelhead
- Half-pounders
- Southern steelhead
- Information Relating to the Species
Question
- Groupings of Oncorhynchus
mykiss
- Phylogenetic Groups
- Life History Variations
- Reproductive
ecotypes
- A- and B-run
steelhead
- Half-pounders
- Rainbow and redband
trout
- Environmental Features
- West Coast
Ichthyogeography
- Geological events
- Ecoregions
- Ichthyogeographical
classification
- Marine and estuarine
ichthyogeography
- Hydrology
- Steelhead Life History and
Ecology
- Migration and Spawn
Timing
- Ageing
- Smolt age
- Ocean age
- Total age
- Repeat Spawning
- Resident Fish
- Steelhead Genetics
- Previous Studies of
Population Genetic Structure
- Protein
electrophoresis
- DNA
- Chromosomal
studies
- Comparison of Steelhead
and Rainbow Trout
- Run Timing
- New Studies
- Synthesis and
Discussion
- Discussion and Conclusions on
ESU Determinations
- Evolutionary
Significance of Phylogenetic and Life History Forms
- Resident fish
- Coastal Steelhead ESUs
- 1) Puget Sound
- 2) Olympic
Peninsula
- 3) Southwest
Washington
- 4) Lower Columbia
River
- 5) Upper Willamette
River
- 6) Oregon Coast
- 7) Klamath Mountains
Province
- 8) Northern
California
- 9) Central California
Coast
- 10) South-Central
California Coast
- 11) Southern
California
- 12) Central Valley
- Inland Steelhead
ESUs
- 13) Middle
Columbia River
- 14) Upper Columbia
River
- 15) Snake River
Basin
- Relationship of Steelhead
ESUs to State Conservation Management
Units
- Relationship of Steelhead
ESUs to Boundaries for Coho Salmon ESUs
- Artificial Propagation
- Grand Coulee Fish
Maintenance Project
- Widespread Steelhead
Broodstocks
- Chambers Creek winter
steelhead
- Skamania summer
steelhead
- Alsea River winter
steelhead
- Big Creek and Cowlitz
River winter steelhead
- Eel River winter
steelhead
- Wells Hatchery summer
steelhead
- Lyons Ferry summer
steelhead
- Dworshak summer
steelhead
- Summary of Artificial
Propagation by ESU
- 1) Puget Sound
- 2) Olympic
Peninsula
- 3) Southwest Washington
- 4) Lower Columbia
River
- 5) Upper Willamette
River
- 6) Oregon Coast
- 7) Klamath Mountains
Province
- 8) Northern
California
- 9) Central California
Coast
- 10) South-Central
California Coast
- 11) Southern
California
- 12) Central Valley
- 13) Middle Columbia
River
- 14) Upper Columbia
River
- 15) Snake River
Basin
-
Assessment of Extinction Risk
- Background
- Absolute Numbers
- Historical Abundance and
Carrying Capacity
- Trends in Abundance
- Factors Causing
Variability
- Threats to Genetic
Integrity
- Recent Events Affecting
Extinction Risk
- Other Risk Factors
- Approach to Risk Assessment
- Previous Assessments
- Data Evaluations
- Data types
- Computed
statistics
- Run timing
- Analysis of Biological
Information
- Coastal Steelhead ESUs
- 1) Puget Sound
- 2) Olympic
Peninsula
- 3) Southwest Washington
- 4) Lower Columbia
River
- 5) Upper Willamette
River
- 6) Oregon Coast
- 7) Klamath Mountains
Province
- 8) Northern
California
- 9) Central California
Coast
- 10) South-Central
California Coast
- 11) Southern
California
- 12) Central Valley
- Inland Steelhead ESUs
- 13) Middle Columbia
River
- 14) Upper Columbia
River
- 15) Snake River
Basin
- Conclusions
- Coastal Steelhead ESU
Conclusions
- 1) Puget Sound
- 2) Olympic Peninsula
- 3) Southwest
Washington
- 4) Lower Columbia
River
- 5) Upper Willamette
- 6) Oregon Coast
- 7) Klamath Mountains
Province
- 8) Northern
California
- 9) Central California
Coast
- 10) South-Central
California Coast
- 11) Southern
California
- 12) Central Valley
- Inland Steelhead ESU
Conclusions
- 13) Middle Columbia
- 14) Upper Columbia
- 15) Snake River
Basin
Citations
Appendix A - Samples of Oncorhynchus
mykiss used in Genetic Analyses
Appendix B - Petitioned Steelhead
Populations Listed by Evolutionarily Significant
Unit
Appendix C - Steelhead Artificial
Propagation Facilities
Appendix D - Releases of Hatchery
Steelhead
Appendix E - Steelhead Abundance Data
Appendix F - Glossary
EXECUTIVE SUMMARY
In February 1994, the National Marine Fisheries Service (NMFS) received a
petition
seeking protection under the Endangered Species Act (ESA) for 178 populations of
steelhead
(anadromous Oncorhynchus mykiss) in Washington, Idaho, Oregon, and
California. At the
time, NMFS was conducting a status review of coastal steelhead populations (O. m.
irideus) in
Washington, Oregon, and California. In response to the broader petition, NMFS
expanded the
ongoing status review to include inland steelhead (O. m. gairdneri)
occurring east of the
Cascade Mountains in Washington, Idaho, and Oregon. This report summarizes
biological and
environmental information considered by the Biological Review Team (BRT) that
conducted
the West Coast Steelhead Status Review.
The ESA allows listing of "distinct population segments" of vertebrates as
well as
named species and subspecies. The policy of the NMFS on this issue for
anadromous Pacific
salmonids is that a population will be considered "distinct" for purposes of the
ESA if it
represents an evolutionarily significant unit (ESU) of the species as a whole.
To be considered
an ESU, a population or group of populations must 1) be substantially
reproductively isolated
from other populations, and 2) contribute substantially to the ecological or
genetic diversity of
the biological species. Once an ESU is identified, a variety of factors related
to population
abundance are considered in determining whether a listing is warranted.
West Coast Steelhead ESUs
After considering available information on steelhead genetics, phylogeny and
life
history, freshwater ichthyogeography, and environmental features that may affect
steelhead,
the BRT identified 15 ESUs--12 for coastal steelhead and 3 for the inland form.
The BRT
reviewed population abundance data and other risk factors for these steelhead
ESUs and
concluded that five (Central California Coast, South-Central California Coast,
Southern
California, Central Valley, and Upper Columbia River) are presently in danger of
extinction,
five (Lower Columbia River, Oregon Coast, Klamath Mountains Province, Northern
California, and Snake River Basin) are likely to become endangered in the
foreseeable future,
and four steelhead ESUs (Puget Sound, Olympic Peninsula, Southwest Washington,
and Upper
Willamette River) are not presently in significant danger of becoming extinct or
endangered,
although some individual stocks within these ESUs may be at risk. The BRT
concluded that
the remaining steelhead ESU (Middle Columbia River) is not presently in danger of
extinction
but was unable to reach a conclusion as to its risk of becoming endangered in the
foreseeable
future.
The BRT concluded that, in general, the ESUs described below include
resident
O. mykiss in cases where they have the opportunity to interbreed with
anadromous fish.
Resident populations above long-standing natural barriers, and those that have
resulted from
the introduction of non-native rainbow trout, would not be considered part of the
ESUs.
Resident populations that inhabit areas upstream from human-caused migration
barriers (e.g.,
Grand Coulee Dam, the Hells Canyon Dam complex, and numerous smaller barriers in
California) may contain genetic resources similar to those of anadromous fish in
the ESU, but
little information is available on these fish or the role they might play in
conserving natural
populations of steelhead. The status, with respect to steelhead ESUs, of
resident fish upstream
from human-caused migration barriers must be evaluated on a case-by-case basis as
more
information becomes available.
Coastal Steelhead ESUs
1) Puget Sound--This ESU occupies river basins of the Strait of Juan
de Fuca, Puget
Sound, and Hood Canal, Washington. Included are river basins as far west as the
Elwha River
and as far north as the Nooksack River. This ESU is primarily composed of winter
steelhead
but includes several populations of summer steelhead. The steelhead in this ESU
generally
smolt at age 2 years, whereas most steelhead in British Columbia smolt at age 3.
Steelhead
from this area are genetically distinct from those in other areas of Washington,
both
chromosomally and electrophoretically. Habitat in the Puget Sound region is
dominated by
glacial effects, including extensive alluvial floodplains, and the fjord-like
structure of Puget
Sound itself may promote distinctive steelhead migration patterns. Recent
population trends
within the Puget Sound ESU are predominantly downward; however, trends in the two
largest
stocks (Skagit and Snohomish Rivers) have been upward. The BRT was concerned
about the
large proportion of hatchery steelhead in Puget Sound and their origination
primarily from a
single stock; however, most hatchery fish appear to have advanced run timing and
to be
harvested prior to spawning, thus limiting their interactions with naturally
spawning steelhead.
Another concern of the BRT was the lack of information on the abundance and
status of
summer steelhead in this ESU.
2) Olympic Peninsula--This ESU occupies river basins of the Olympic
Peninsula,
Washington, west of the Elwha River and south to, but not including, the rivers
that flow into
Grays Harbor on the Washington coast. The Olympic Peninsula ESU is primarily
composed
of winter steelhead but includes several populations of summer steelhead in the
larger rivers.
Olympic Peninsula steelhead are genetically distinct from other steelhead ESUs;
this isolation
is also supported by zoogeographic patterns of other species of fish and
amphibians, indicating
a faunal shift in the vicinity of the Chehalis River Basin. Population trends
within this ESU
are generally upward, with some stocks declining. As was the case with the Puget
Sound
ESU, there is very little information regarding the abundance and status of
summer steelhead
in this region, and there is also uncertainty regarding the degree of interaction
between
hatchery and natural stocks.
3) Southwest Washington--This ESU occupies the tributaries to Grays
Harbor,
Willapa Bay, and the Columbia River below the Cowlitz River in Washington and
below the
Willamette River in Oregon. This ESU is primarily composed of winter steelhead
but includes
summer steelhead in the Humptulips and Chehalis River Basins. Genetic data show
differentiation between steelhead of this ESU and those of adjacent regions. The
ecological
connectivity of the region occupied by the Southwest Washington ESU is
demonstrated by
similarities in riverine and estuarine ichthyofauna and current-driven sediment
transfer from
the Columbia River to Grays Harbor and Willapa Bay. Most population trends
within this
ESU have been declining in the recent past. There is very little information
regarding the
abundance and status of summer steelhead in this region, and there is also
uncertainty
regarding the degree of interaction between hatchery and natural stocks.
4) Lower Columbia River--This ESU occupies tributaries to the
Columbia River
between the Cowlitz and Wind Rivers in Washington and the Willamette and Hood
Rivers in
Oregon, inclusive. Excluded are steelhead in the upper Willamette River Basin
above
Willamette Falls (see ESU 5-Upper Willamette River), and steelhead from the
Little and Big
White Salmon Rivers, Washington (see ESU 13-Middle Columbia River ESU). This ESU
is
composed of both winter and summer steelhead. Genetic data show distinction
between
steelhead of this ESU and adjacent regions, with a particularly strong difference
between
coastal and inland steelhead in the vicinity of the Cascade Crest. The majority
of stocks for
which we have data within this ESU have been declining in the recent past, but
some have
been increasing strongly. However, the strongest upward trends are either
non-native stocks
(Lower Willamette River and Clackamas River summer steelhead) or stocks that are
recovering
from major habitat disruption and are still at low abundance (mainstem and North
Fork Toutle
River). The data series for most stocks is quite short, so the preponderance of
downward
trends may reflect the general coastwide decline in steelhead in recent years.
5) Upper Willamette River--This ESU occupies the Willamette River and
its
tributaries upstream from Willamette Falls. The native steelhead of this basin
are
late-migrating winter steelhead, entering fresh water primarily in March and
April. This
unusual run timing appears to be an adaptation for ascending Willamette Falls,
which function
as an isolating mechanism for upper Willamette River steelhead. Early migrating
winter
steelhead and summer steelhead have been introduced to the Upper Willamette River
Basin;
however, these non-native populations are not components of this ESU. Native
winter
steelhead within this ESU have been declining on average since 1971 and have
exhibited large
fluctuations in abundance. The main production of native (late-run) winter
steelhead is in the
North Fork Santiam River, where estimates of hatchery proportion in natural
spawning range
from 14% to 54%.
6) Oregon Coast--This ESU occupies river basins on the Oregon coast
north of Cape
Blanco; excluded are rivers and streams that are tributaries of the Columbia
River (see ESU 3-
Southwest Washington). Native Oregon Coast steelhead are primarily winter
steelhead; native
summer steelhead occur only in the Siletz and Umpqua River Basins. Recent
genetic data for
steelhead in this ESU show a level of differentiation from populations from
Washington, the
Columbia River Basin, and coastal areas south of Cape Blanco. Ocean migration
patterns also
suggest a distinction between steelhead populations north and south of Cape
Blanco.
Steelhead, as well as chinook (O. tshawytscha) and coho (O.
kisutch) salmon, from streams
south of Cape Blanco tend to be south-migrating rather than north-migrating.
Most steelhead
populations within this ESU have been declining in the recent past, with
increasing trends
restricted to the southernmost portion (south of Siuslaw Bay). There is
widespread production
of hatchery steelhead within this ESU, largely based on out-of-basin stocks, and
approximately
half of the streams (including the majority of those with upward trends) are
estimated to have
more than 50% hatchery fish in natural spawning escapements. Given the
substantial
contribution of hatchery fish to natural spawning throughout the ESU and the
generally
declining or slightly increasing trends, it is likely that natural stocks are not
replacing
themselves throughout the ESU.
7) Klamath Mountains Province--This ESU occupies river basins from
the Elk River
in Oregon to the Klamath and Trinity Rivers in California, inclusive. This ESU
includes both
winter and summer steelhead. Steelhead from this region are genetically distinct
from
populations to the north and south. The "half-pounder" life history is reported
only from this
region. The Klamath Mountains Province is a unique geographical area with
unusual geology
and plant communities. While absolute abundance of steelhead within the ESU
remains fairly
high, since about 1970 trends in abundance have been downward in most steelhead
populations
for which we have data, and a number of populations are considered by various
agencies and
groups to be at some risk of extinction. Declines in summer steelhead
populations are of
particular concern. This ESU was previously studied under a separate status
review that was
completed in December 1994 (Busby et al. 1994).
8) Northern California--This ESU occupies river basins from Redwood
Creek in
Humboldt County, California south to the Gualala River, inclusive, and includes
winter and
summer steelhead. Allozyme and mitochondrial DNA data indicate genetic
discontinuities
between steelhead of this region and those to the north and south. Freshwater
fish species
assemblages in this region are derived from the Sacramento River Basin, whereas
streams to
the north include fishes representative of the Klamath-Rogue ichthyofaunal
province.
Population abundances are very low relative to historical estimates, and recent
trends are
downward in stocks for which we have data, except for two small summer steelhead
stocks.
Summer steelhead abundance is very low. Risk factors identified for this ESU
include
freshwater habitat deterioration due to sedimentation and flooding related to
land management
practices and introduced Sacramento squawfish as a predator in the Eel River.
For certain
rivers (particularly the Mad River), the BRT is concerned about the influence of
hatchery
stocks, both in terms of genetic introgression and potential ecological
interactions between
introduced stocks and native stocks.
9) Central California Coast--This ESU occupies river basins from the
Russian River
to Soquel Creek, Santa Cruz County (inclusive) and the drainages of San Francisco
and San
Pablo Bays; excluded is the Sacramento-San Joaquin River Basin of the Central
Valley of
California. Mitochondrial DNA and allozyme data indicate genetic differences
between the
steelhead from this region and those from adjacent areas. Environmental features
(e.g., precipitation patterns, vegetation, and soils) show a transition in this
region from the
northern redwood forest ecosystem to the more xeric southern chaparral and
coastal scrub
ecosystems. Steelhead populations within the major streams occupied by this ESU
appear to
be greatly reduced from historical levels; for example, steelhead abundance in
the Russian
River has been reduced roughly sevenfold since the mid-1960s, but abundance in
smaller
streams appears to be stable at low levels. The primary risk factor for this ESU
is deteriorated
habitat due to sedimentation and flooding related to land management practices.
Uncertainty
regarding the genetic heritage of the natural populations in tributaries to San
Francisco and San
Pablo Bays makes it difficult to determine which of these populations should be
considered
part of the ESU.
10) South-Central California Coast--This ESU occupies rivers from the
Pajaro River,
Santa Cruz County to (but not including) the Santa Maria River. Mitochondrial
DNA data
provide evidence for a genetic transition in the vicinity of Monterey Bay. Both
mtDNA and
allozyme data show large genetic differences between populations in this area,
but do not
provide a clear picture of population structure. The climate in this region is
drier and warmer
than it is to the north, resulting in chaparral and coastal scrub vegetation and
stream mouths
that are closed seasonally by sand berms. In addition to vegetation transitions,
the northern
end of this region is the southern limit of the distribution of coho salmon. The
southern
boundary of this ESU is near Point Conception, a well-recognized transition area
for the
distribution and abundance of marine flora and fauna. Total abundance of
steelhead in this
ESU is extremely low and declining. Risk factors for this ESU are habitat
deterioration due to
sedimentation and flooding related to land management practices and potential
genetic
interaction with hatchery rainbow trout.
11) Southern California--This ESU occupies rivers from the Santa
Maria River to the
southern extent of the species range. Steelhead occur at least as far south as
Malibu Creek,
Los Angeles County, and may have historically occurred as far south as the
U.S.-Mexico
border. Genetic data show large differences between steelhead populations within
this ESU as
well as between these and populations to the north. Average rainfall is
substantially lower and
more variable in southern California than in regions to the north, resulting in
increased
duration of sand berms across the mouths of streams and rivers and, in some
cases, complete
dewatering of the lower reaches of these streams from late spring through fall.
This affects
steelhead migration patterns, as well as the ability to residualize and survive
elevated water
temperatures. Steelhead have already been extirpated from much of their
historical range in
this region. The BRT had a strong concern about the widespread degradation,
destruction, and
blockage of freshwater habitats within the region, and the potential results of
continuing
habitat destruction and water allocation problems. There was also concern about
the genetic
effects of widespread stocking of rainbow trout.
12) Central Valley--This ESU occupies the Sacramento and San Joaquin
Rivers and
their tributaries. Recent allozyme data show that samples of steelhead from Deer
and Mill
Creeks and Coleman National Fish Hatchery on the Sacramento River are well
differentiated
from all other samples of steelhead from California. The Sacramento and San
Joaquin Rivers
offer the only migration route to the drainages of the Sierra Nevada and southern
Cascade
mountain ranges for anadromous fish. The distance from the ocean to spawning
streams can
exceed 300 km, providing unique potential for reproductive isolation among
steelhead in
California. Steelhead have already been extirpated from most of their historical
range in this
region. Habitat concerns in this ESU focus on the widespread degradation,
destruction, and
blockage of freshwater habitats within the region, and the potential results of
continuing
habitat destruction and water allocation problems. The BRT also had a strong
concern about
the pervasive opportunity for genetic introgression from hatchery stocks within
the ESU, and a
strong concern for potential ecological interactions between introduced stocks
and native
stocks.
Inland Steelhead ESUs
13) Middle Columbia River--This ESU occupies the Columbia River Basin
from
above the Wind River in Washington and the Hood River in Oregon upstream to
include the
Yakima River, Washington. Steelhead of the Snake River Basin are not included.
This ESU
includes the only populations of winter inland steelhead in the United States, in
the Klickitat
River and Fifteenmile Creek. Some uncertainty exists about the exact boundary
between
coastal and inland steelhead, and the western margin of this ESU reflects
currently available
genetic data. There is good genetic and meristic evidence to separate this ESU
from steelhead
of the Snake River Basin. The boundary upstream of the Yakima River is based on
limited
genetic information and environmental differences including physiographic
regions, climate,
topography, and vegetation. All BRT members felt special concern for the status
of this ESU,
particularly Yakima River and winter steelhead stocks. Total steelhead abundance
in the ESU
appears to have been increasing recently, but the majority of natural stocks for
which we have
data within this ESU have been declining, including those in the John Day River,
which is the
largest producer of wild, natural steelhead. There is widespread production of
hatchery
steelhead within this ESU, but it is largely based on within-basin stocks.
Habitat degradation
due to grazing and water diversions has been documented throughout the range of
the ESU.
14) Upper Columbia River--This ESU occupies the Columbia River Basin
upstream
from the Yakima River. All upper Columbia River steelhead are summer steelhead.
The
streams of this region that are utilized by steelhead primarily drain the
northern Cascade
Mountains of Washington State. Streamflow is supplied by snowmelt, groundwater,
and
glacial runoff, often resulting in extremely cold water temperatures that retard
the growth and
maturation of steelhead juveniles, causing some of the oldest smolt ages reported
for steelhead
and residualization of juvenile steelhead that fail to smolt. All anadromous
fish in this region
were affected by the Grand Coulee Fish Maintenance Project (1939 through 1943),
wherein
anadromous fish returning to spawn in the upper Columbia River were trapped at
Rock Island
Dam, downstream of the Wenatchee River. Some of these fish were then released to
spawn in
river basins above Rock Island Dam, while others were spawned in hatcheries and
the
offspring were released into various upper Columbia River tributaries; in both
cases, no
attempt was made to return these fish to their natal streams, resulting in an
undetermined level
of stock mixing within the upper Columbia River fish. While total abundance of
populations
within this ESU has been relatively stable or increasing, this appears to be true
only because of
major hatchery supplementation programs. Estimates of the proportion of hatchery
fish in
spawning escapement are 65% (Wenatchee River) and 81% (Methow and Okanogan
Rivers).
The major concern for this ESU is the clear failure of natural stocks to replace
themselves.
The BRT also had a strong concern about problems of genetic homogenization due to
hatchery
supplementation within the ESU. There was also concern about the apparent high
harvest rates
on steelhead smolts in rainbow trout fisheries and the degradation of freshwater
habitats within
the region, especially the effects of grazing, irrigation diversions, and
hydroelectric dams.
15) Snake River Basin--This ESU occupies the Snake River Basin of
southeast
Washington, northeast Oregon, and Idaho. This region is ecologically complex and
supports a
diversity of steelhead populations; however, genetic and meristic data suggest
that these
populations are more similar to each other than they are to steelhead populations
occurring
outside of the Snake River Basin. Snake River Basin steelhead spawning areas are
well
isolated from other populations and include the highest elevations for spawning
(up to
2,000 m) as well as the longest migration distance from the ocean (up to 1,500
km). Snake
River steelhead are often classified into two groups, A- and B-run, based on
migration timing,
ocean age, and adult size. While total (hatchery + natural) run size for Snake
River steelhead
has increased since the mid-1970s, the increase has resulted from increased
production of
hatchery fish, and there has been a severe recent decline in natural run size.
The majority of
natural stocks for which we have data within this ESU have been declining. Parr
densities in
natural production areas have been substantially below estimated capacity in
recent years.
Downward trends and low parr densities indicate a particularly severe problem for
B-run
steelhead, the loss of which would substantially reduce life history diversity
within this ESU.
The BRT had a strong concern about the pervasive opportunity for genetic
introgression from
hatchery stocks within the ESU. There was also concern about the degradation of
freshwater
habitats within the region, especially the effects of grazing, irrigation
diversions, and
hydroelectric dams.
ACKNOWLEDGMENTS
This document represents the combined efforts of dozens of people who
submitted
information on steelhead directly to NMFS; attended Biological and Technical
Committee
meetings in Washington, Idaho, Oregon, and California; and answered seemingly
endless
questions from the authors and biological review team (BRT) members on the
telephone. The
authors particularly wish to acknowledge Stevan Phelps and Steve Leider of the
Washington
Department of Fish and Wildlife for generous sharing of newly emerging genetic
data, and
Jennifer Nielsen of Hopkins Marine Laboratory for sharing her DNA studies in
progress. We
also wish to thank those that reviewed drafts of this and related documents.
Significant contributions in the compilation and analyses of data were made
by
Kathleen Neely, Ted Parker, and David Teel, all from NMFS Northwest Fisheries
Science
Center (NWFSC). The biological review team for this status review included Peggy
Busby,
Dr. Stephen Grabowski, Dr. Robert Iwamoto, Dr. Conrad Mahnken, Gene Matthews,
Dr. Michael Schiewe, Dr. Thomas Wainwright, Dr. Robin Waples, and Dr. John
Williams,
from NMFS NWFSC; Greg Bryant and Craig Wingert from NMFS Southwest Region (SWR);
and Dr. Reg Reisenbichler from the National Biological Service (NBS), Seattle.
Table of Contents
