Order Code 98-666
Updated June 28, 2007
Pacific Salmon and Steelhead Trout:
Managing Under the Endangered Species Act
Eugene H. Buck
Specialist in Natural Resources Policy
Resources, Science, and Industry Division
Summary
Along the Pacific Coast, 26 distinct population segments of Pacific salmon and
steelhead trout are listed as either endangered or threatened under the Endangered
Species Act (ESA). Human activities have combined to greatly degrade, reduce, and
eliminate fish habitat and otherwise harm populations of anadromous (sea-run) fish. In
addition, natural phenomena stress fish populations and contribute to their variable
abundance. Current management efforts aim to restore the abundance of ESA-listed
native northeast Pacific salmonids to historic, sustainable population levels. This report
summarizes the reasons for ESA listings and outlines efforts to protect ESA-listed
species. This report will be updated periodically to reflect the changing situation.
Background. Pacific chinook, coho, chum, sockeye, and pink salmon as well as
steelhead trout are anadromous (i.e., they live as juveniles in fresh water, migrate to the
ocean to develop, and, when sexually mature, return to freshwater to spawn). While
steelhead trout and Atlantic salmon can return to the sea after spawning (and may spawn
again in subsequent years), Pacific salmon die after spawning once. Juvenile salmon
typically reside in fresh water from a few days (pink salmon) to three years (some sockeye
salmon) before migrating to the ocean, where they typically spend 1-6 years before
migrating to their natal stream, as much as 900 miles or more inland. Natural phenomena
— predators, droughts, floods, and fluctuating oceanic conditions — stress salmonids and
contribute to the variable abundance of their populations. El Niño, Pacific decadal
oscillation,1 and global climate change2 have been of particular concern as factors altering
salmon habitat and affecting salmon distribution and abundance.
Precipitous salmon declines in the 1990s hurt the economies of fishing-dependent
communities throughout the Northwest and northern California. By the late 1990s, west
1 N. J. Mantua et al., “A Pacific interdecadal climate oscillation with impacts on salmon
production,” Bulletin of the American Meteorological Society, v. 78 (1997): 1069-1079.
2 See [http://www.usgcrp.gov/usgcrp/Library/nationalassessment/10NW.pdf].

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coast salmon abundance had declined to only 10%-15% of what it had been in the 1800s.3
As recently as 1988, sport and commercial salmon fishing in that region generated more
than $1.25 billion for the regional economy. Since then, salmon fishing closures have
contributed to the loss of nearly 80% of this region’s job base, with a total salmon
industry loss over the past 30 years of approximately 72,000 family wage jobs.4
Currently, 26 distinct population segments of five salmonid species have been listed
or proposed for listing as either endangered or threatened under the Endangered Species
Act (ESA, see Table 1).5 While no species of anadromous trout or salmon is in danger
of near-term extinction, individual population segments (designated as “evolutionarily
significant units”6) within these species have declined substantially or have even been
extirpated. The American Fisheries Society considers at least 214 Pacific Coast
anadromous fish populations to be “at risk,” while at least 106 other historically abundant
populations have already become extinct.7
Human Activities Stressing Fish. Anadromous salmonids inhabit clean, silt-
free streams of low water temperature (below 68° F) and quality estuarine nursery habitat.
Human activities — logging, grazing, mining, agriculture, urban development, and
consumptive water use — can degrade aquatic habitat. Silt can cover streambed gravel,
smothering eggs. Poorly constructed roads often increase siltation in streams where adult
salmon spawn and young salmon rear. Removal of streamside trees and shade frequently
leads to higher water temperatures. Grazing cattle remove streamside vegetation and
exacerbate streambank erosion. Urbanization typically brings riprap channelization and
filled wetlands, altering food supplies and nursery habitat. Habitat alterations can lead
to increased salmonid predation by marine mammals, birds, and other fish. Water
diversions for agriculture exacerbate these problems. According to state water resource
agencies, almost every water basin in Oregon, eastern Washington, and northern
California is now over-appropriated (i.e., there are more legal permits for diversion than
available water) during the hottest and driest months of the year.
3 E. Winninghoff, “Where Have All the Salmon Gone?” Forbes (Nov. 21, 1994), pp. 104-116.
4 Pacific Rivers Council. The Economic Imperative of Protecting Riverine Habitat in the Pacific
Northwest. Eugene, OR: January 1992; and “Statement of Glen Spain of the Pacific Coast
Federation of Fishermen’s Associations” in: U.S. Senate, Committee on Environment and Public
Works, Subcommittee on Drinking Water, Fisheries, and Wildlife. Endangered Species Act
Reauthorization. Hearing, June 1, 1995. Roseburg, OR: U.S. Govt. Print. Off. pp. 123-142.
5 Table information taken from: U.S. Dept. of Commerce, National Marine Fisheries Service,
“Snapshot of ESU Status” ([http://www.nwr.noaa.gov/ESA-Salmon-Listings/upload/snapshot
0607.pdf], updated June 15, 2007).
6 NMFS uses the term “evolutionarily significant unit” (ESU) as synonymous to a distinct
population segment that appears to be reproductively isolated from other segments (56 Federal
Register 58612, Nov. 20, 1991).
7 Willa Nehlsen, Jack Williams, and James Lichatowich, “Pacific Salmon at the Crossroads:
Stocks at Risk from California, Oregon, Idaho, and Washington,” Fisheries, v. 16 (1991), pp. 4-
21; and T. L. Slaney et al. “Status of Anadromous Salmon and Trout in British Columbia and
Yukon,” Fisheries, v. 21 (October 1996), pp. 20-35.

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Dams for hydropower, flood control, and irrigation substantially alter aquatic habitat
and can have significant impacts on anadromous fish. While the design of some dams is
described as “fish-friendly” (e.g., Wells Dam on the Columbia River in Washington),
poorly designed dams can physically bar or impede anadromous fish migrations to and
from the sea, kill juveniles as they pass through a dam’s turbines, and expose fish to
potentially harmful gas supersaturation.8 If delayed by dams during migration, both young
and old salmon can be exposed to increased predation, to an increased risk of bacterial
infections, and to higher temperatures which cause stress and sometimes death.9
Decreased river flow can also harm juveniles by delaying their downstream migration.
However, the 31 dams (i.e., hydro projects) in the Federal Columbia River Power System
produce about 40% of the power in the Pacific Northwest, and the reservoirs behind these
dams create a major navigable waterway as far inland as Lewiston, Idaho.
The goal of fish hatcheries, operated along the Pacific Coast since 1877, was, and
continues to be, the augmentation of natural salmonid populations and the production of
fish to replace those lost where dams completely blocked passage and destroyed native
salmonid populations. Today, at least 80% of the salmon caught commercially in the
Pacific Northwest and northern California each year come from hatcheries. In the 1970s,
however, scientists discovered that some hatchery practices reduced genetic diversity in
fish populations.10 The mixing of populations by hatcheries and transplantation has
generally resulted in decreased genetic fitness of wild populations and the loss of some
stream-specific adaptations. Also, hatchery fish generally have lower survival rates than
wild fish, and are less able to adjust to changing ocean conditions or to escape predators.
The harvest of intermingled fish populations from different watersheds presents
several problems, including how to protect ESA-listed populations while promoting the
harvest of abundant native and hatchery fish. Since hatcheries are often more productive
than natural fish populations, managing fisheries to avoid surplus returns to hatcheries can
result in overharvested natural populations. Controversy arises when managers must
consider how much the harvest of abundant populations must be curtailed to protect less-
abundant ESA-listed populations. Such policies can frustrate both commercial fishermen
and sport anglers. ESA-listed or seriously depressed populations thus can become the
limiting factor on fisheries, resulting in tens of millions of dollars in foregone fishing
opportunities to avoid further depressing the weakest populations.
Protection and Restoration Efforts. The National Marine Fisheries Service
(NMFS, also popularly referred to as “NOAA Fisheries”) in the Department of Commerce
implements the ESA for anadromous salmonids. NMFS receives a petition or initiates
the process to determine whether a species or population merits listing as “endangered”
or “threatened.” Based on facts presented, the Secretary of Commerce decides whether
the petition provides substantial information indicating that listing may be warranted. If
8 Water spilled from dams and passing through turbines can become supersaturated with gaseous
nitrogen. Juvenile fish exposed to supersaturated conditions can develop disorienting gas bubble
disease and become more susceptible to predation.
9 G. F. Cada et al., “Effects of Water Velocity on the Survival of Downstream-Migrating Juvenile
Salmon and Steelhead: A Review with Emphasis on the Columbia River Basin,” Reviews in
Fisheries Science, v. 5, no. 2 (1997): 131-183.
10 Jack Stern, Jr., “Supplementation of Wild Salmon Stocks: A Cure for the Hatchery Problem
or More Problem Hatcheries?” Coastal Management, v. 23 (1995), pp. 123, 140.

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the Secretary decides affirmatively, a 90-day notice announcing the initiation of a status
review is published in the Federal Register. Once the status review is completed, NMFS
publishes a notice of proposed rulemaking in the Federal Register and seeks public
comment for those species or populations NMFS believes should be listed. A final listing
decision must occur within 12 months after notice publication. Once listed, NMFS is
required to designate critical habitat11 as well as develop and publish a recovery plan for
the listed entity.12 The goal of ESA listing is species recovery, defined as removal from
the ESA list. (For more on the ESA process, see CRS Report RL31654, The Endangered
Species Act: A Primer, by Pamela Baldwin, Eugene H. Buck, and M. Lynn Corn.)
When a federal activity may harm an ESA-listed salmonid, the ESA requires the
federal agency to consult with NMFS to determine whether the activity is likely to
jeopardize the survival and recovery of the species or adversely modify its critical habitat.
In response to a federal agency’s biological assessment, NMFS issues a “biological
opinion” (BiOp) with an incidental “take” statement which can authorize a limited take
of the species and specifies reasonable and prudent measures to minimize such taking.
If NMFS issues a jeopardy opinion, it includes a reasonable and prudent alternative (RPA)
which would not be expected to jeopardize the continued existence of the species. NMFS
issues numerous BiOps related to salmon each year. For example, a 1995 BiOp for the
U.S. Army Corps of Engineers and the Bonneville Power Administration sought to
develop a biologically sound strategy to deal with salmon passage in the Columbia and
Snake Rivers. The major impact of this 1995 BiOp and its 1998 supplement has been the
move away from transporting the majority of juvenile salmonids downstream by truck or
barge, and implementing a “spread the risk” policy which calls for an increase in spilling
water and fish over dams, thus circumventing the power-producing turbines, to speed
juvenile fish through the river toward the ocean with lower mortality. In 2000, the Corps
completed a System Operations Review of the Columbia and Snake River hydropower
system, with breaching the four lower Snake River dams being considered as one option.
In December 2000, NMFS issued a revised BiOp that reviewed the strategies outlined in
the 1995 and 1998 BiOps and recommended changes. This BiOp did not recommend
breaching the four Lower Snake River dams, but did include steps to consider breach
should the RPA fail. A revised 2004 “no jeopardy” BiOp did not include breaching and
is under remand to NOAA by the Federal District Court of Oregon (although not due to
breaching issues).13
Prior to the listing of salmonid ESUs under the ESA, the majority of conservation
and habitat management efforts were conducted by individual states, tribes, and private
industries. In the Columbia River Basin, the Northwest Power and Conservation Council
took the lead under the 1980 Pacific Northwest Electric Power Planning and Conservation
Act (P.L. 96-501), by attempting to protect salmon and their habitat while also providing
economical power to the region. Although federal agencies and public utilities spend
hundreds of millions of dollars on technical improvements for dams, habitat enhancement,
and water purchases to improve salmon survival, some populations have continued to
11 There may be no critical habitat designation, if NMFS decides that it is not prudent, and the
critical habitat designation may be delayed up to a year if it is not determinable. In practice, only
about 20% of listed species have designated critical habitat.
12 For information on current recovery efforts, see [http://www.nwfsc.noaa.gov/trt/index.cfm].
13 The BiOp text may be viewed at [http://seahorse.nmfs.noaa.gov/pls/pcts-pub/sxn7.pcts_upload.
summary_list_biop?p_id=14756].

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decline. Recent years have seen an increased interest by state governments and tribal
councils in developing comprehensive salmon management efforts. States generally seek
to forestall ESA listings, or, if listings do occur, to reduce federal involvement affecting
state-managed lands. With limited staff and funding to implement a wide range of
programs, NMFS has encouraged integrated management efforts (i.e., habitat
conservation plans) among federal, state, and tribal agencies as a powerful and necessary
tool in saving listed species and avoiding future listing of additional ESUs through
comprehensive recovery efforts.14 NMFS viewed the Oregon Coastal Salmon Restoration
Initiative (OCSRI), to promote comprehensive and proactive state-based recovery efforts
and avoid listing coho salmon in Oregon, as precedent for federal/state/local partnerships.
However, a federal court decision clarified that, to avoid an eventual listing, such plans
cannot be based primarily on speculative or proposed future measures, but must instead
be based on recovery measures that are enforceable or reasonably likely to occur, as, for
instance, measures embodied in laws, regulations, or long-range and stable funding
mechanisms.15 With the listing of many salmonid ESUs in the Columbia River basin,
management has become increasingly constrained, and new options for governance are
being explored by federal, state, and tribal parties. Restoration efforts for some California
salmon, including water reforms, were embodied in the Central Valley Project
Improvement Act (Title XXXIV of P.L. 102-575) and the San Joaquin River Restoration
Program.16 The U.S. Fish and Wildlife Service (FWS) has coordinated plans for fish
screens, fish ladders, and water pollution reduction to recover native fish populations in
the Central Valley Project area.
In 1993, NMFS issued an interim policy on artificial propagation of Pacific salmon
under the ESA to guide how hatcheries should be used to help recover salmonids.17 In
response to litigation, a policy statement defined how hatchery fish are to be treated when
deciding whether ESUs should be listed under the ESA.18 In general, the policy is to
recover wild populations in their natural habitat wherever possible, without resorting to
artificial propagation. Washington, Oregon, and British Columbia mass-mark hatchery
coho salmon by fin clipping so that marked fish can be readily identified by fishermen as
hatchery fish and selectively retained at harvest while unmarked, native fish can be
released to spawn. Similar programs are underway for other species, such as chinook
salmon and steelhead trout. In addition, controversy and resistance remain over suggested
changes to use fishing gear more suitable to releasing wild fish unharmed after being
caught inadvertently. In early 2006, NOAA began a collaborative review to identify (1)
hatchery programs that are not contributing to salmon recovery and (2) ways to reduce the
harvest of ESA-listed fish.19 The FWS initiated a review of Columbia River hatcheries
in May 2005.20
14 Personal communication with Garth Griffin, Branch Chief, Protected Resources Division,
NMFS, Portland, OR, on May 21, 1998.
15 Oregon Natural Resources Council v. Daley, CV-97-1155-ST (D.Or. June 1, 1998).
16 For background information, see [http://www.usbr.gov/mp/SJRRP/index.html].
17 58 Federal Register 17573 (Apr. 5, 1993).
18 70 Federal Register 37204 (June 28, 2005).
19 Background information is available at [http://www.hatcheryreform.us].
20 See [http://www.fws.gov/pacific/Fisheries/Hatcheryreview/index.html].

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Table 1. Status of Five Species of Pacific Coast Salmonids
Species
Population (ESU)
Status
Federal Register (FR) Citation
Pending Actions
Coho salmon
1. Central California
Endangered
1. 70 FR 37160 (June 28, 2005)
(Oncorhynchus
2. Southern Oregon/Northern CA coasts
Threatened
2. 70 FR 37160 (June 28, 2005)
kisutch)
3. Lower Columbia River/Southwest WA
Threatened
3. 70 FR 37160 (June 28, 2005)
Critical habitat under review by NMFS
4. Puget Sound/Strait of Georgia
Species of Concern
4. 69 FR 19975 (Apr. 15, 2004)
Chinook salmon
1. Sacramento River winter-run
Endangered
1. 70 FR 37160 (June 28, 2005)
(Oncorhynchus
2. Upper Columbia River spring-run
Endangered
2. 70 FR 37160 (June 28, 2005)
tshawytscha)
3. Snake River fall-run
Threatened
3. 70 FR 37160 (June 28, 2005)
4. Snake River spring/summer-run
Threatened
4. 70 FR 37160 (June 28, 2005)
5. Central Valley spring-run
Threatened
5. 70 FR 37160 (June 28, 2005)
6. California coastal
Threatened
6. 70 FR 37160 (June 28, 2005)
7. Puget Sound
Threatened
7. 70 FR 37160 (June 28, 2005)
8. Lower Columbia River
Threatened
8. 70 FR 37160 (June 28, 2005)
9. Upper Willamette River
Threatened
9. 70 FR 37160 (June 28, 2005)
10. Central Valley fall and late-fall run
Species of Concern
10. 69 FR 19975 (Apr. 15, 2004)

Chum salmon
1. Hood Canal summer-run
Threatened
1. 70 FR 37160 (June 28, 2005)
(Oncorhynchus keta)
2. Columbia River
Threatened
2. 70 FR 37160 (June 28, 2005)
Sockeye salmon
1. Snake River
Endangered
1. 70 FR 37160 (June 28, 2005)
(Oncorhynchus nerka)
2. Ozette Lake
Threatened
2. 70 FR 37160 (June 28, 2005)
Steelhead trout
1. Southern California
Endangered
1. 71 FR 834 (Jan. 5, 2006)
(Oncorhynchus
2. South-Central California Coast
Threatened
2. 71 FR 834 (Jan. 5, 2006)
mykiss)
3. Central California Coast
Threatened
3. 71 FR 834 (Jan. 5, 2006)
4. Upper Columbia River
Endangered
4. Court decision (June 13, 2007)a
5. Snake River Basin
Threatened
5. 71 FR 834 (Jan. 5, 2006)
6. Lower Columbia River
Threatened
6. 71 FR 834 (Jan. 5, 2006)
7. California Central Valley
Threatened
7. 71 FR 834 (Jan. 5, 2006)
8. Upper Willamette River
Threatened
8. 71 FR 834 (Jan. 5, 2006)
9. Middle Columbia River
Threatened
9. 71 FR 834 (Jan. 5, 2006)
10. Northern California
Threatened
10. 71 FR 834 (Jan. 5, 2006)
11. Oregon Coast
Species of Concern
11. 69 FR 19975 (Apr. 15, 2004)

12. Puget Sound
Threatened
12. 72 FR 26722 (May 11, 2007)
Critical habitat under review by NMFS
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a. Trout Unlimited v. Lohn, No. CV05-1128-JCC (W.D. Wash. June 13, 2007).

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