98-666: Pacific Salmon and Anadromous Trout:
Management Under the Endangered Species Act
Eugene H. Buck
John R. Dandelski
Resources, Science, and Industry Division
Updated October 27, 1999
Along the Pacific Coast, 26 distinct population segments of Pacific
salmon and anadromous (sea-run) trout are listed as either endangered or threatened under
the Endangered Species Act (ESA). A variety of human activities have combined to greatly
reduce or eliminate historic fish habitat, degrade remaining habitat, and otherwise harm
anadromous fish populations. 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 current and proposed 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 sea-run cutthroat and 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 where they hatched to spawn. While some sea-run trout and Atlantic
salmon can return to the sea after spawning (and can 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 3 years (some sockeye salmon) before migrating to the
ocean, where they typically spend 1-6 years before migrating back 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 conditions have been of particular
concern with warmer marine waters reducing food organisms for salmonids and bringing an
abundance of predators, such as mackerel.
By the late 1990s, west coast salmon abundance had declined to only
10-15% of what it had been in the 1800s,(1)
and precipitous salmon declines in recent years have hurt the economies of
fishing-dependent coastal and rural inland communities throughout the Northwest and
northern California. 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
By late October 1999, 26 distinct population segments of five
salmonid species were listed as either endangered or threatened under the Endangered
Species Act (ESA, see table 1).(3)
While no species of anadromous trout or salmon is in danger of near-term
extinction, individual population segments (designated as "evolutionarily significant
units"(4)) 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
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 raises stream 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. In the Klamath River
basin, as much as 90% of the annual flows from the Trinity River have been diverted to
California's Central Valley Project for irrigation. 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.
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.(6) If delayed by dams, 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.(7) Decreased river flow can also harm juveniles by delaying
their downstream migration. However, the eight federally owned mainstem dams in the
Columbia River basin produce about two-thirds of the power in the Pacific Northwest,(8) 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, to augment natural salmonid populations and to produce
fish to replace those lost where dams completely blocked fish 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.(9) 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 the issue of 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 hatchery surpluses overharvests natural populations. Controversy arises when
managers must consider how much the harvest of abundant populations must be curtailed to
protect less-abundant ESA-listed native 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 Efforts. The task of implementing the
ESA for anadromous salmonids falls to the National Marine Fisheries Service (NMFS) in the
Department of Commerce. NMFS can receive a petition or initiate the process to determine
whether a species or population merits listing as either "endangered" or
"threatened." Based on facts presented in the petition, the Secretary of
Commerce decides whether the petition presents substantial information indicating that
listing may be warranted. If the Secretary decides that the petitioned action may be
warranted, 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 publication of the notice. Once listed, NMFS is required
to designate critical habitat(10)
and, finally, develop and publish a recovery plan for the species. The goal of ESA listing
is species recovery, defined as removal from the ESA list. (For more information on the
ESA process, see CRS Issue Brief IB10009, Endangered Species:
Continuing Controversy.) NMFS is in the very early stages of a long
process aimed at recovering ESA-listed salmonid ESUs as well as avoiding future listings.
Most of the effort to date has been directed toward identifying ESUs for listing. This
effort is scheduled to continue through December 1999.
When a federal activity may harm an ESA-listed species, 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 biological assessment submitted by the federal agency,
NMFS issues a "biological opinion" (BO) with an incidental "take"
statement which authorizes a limited take of the species and specifies reasonable and
prudent measures to minimize such taking of the species. If NMFS issues a jeopardy
opinion, it includes a reasonable and prudent alternative which would not be expected to
jeopardize the continued existence of the species. NMFS issues numerous BOs related to
salmon each year. For example, a 1995 BO for the U.S. Army Corps of Engineers and the
Bonneville Power Administration sought to develop a biologically sound (safe) strategy to
deal with salmon passage in the Columbia and Snake Rivers. The major impact of this 1995
BO and its 1998 supplement has been the move away from transporting the majority of
juvenile salmonids downstream via 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. The Corps is also conducting a System Operations
Review, due to be completed late in 1999, of the Columbia and Snake River hydropower
system, with breaching the four lower Snake River dams being considered as one option. In
addition, NMFS is working on a revised BO, to be completed early in 2000, that will review
the strategies outlined in the 1995 and 1998 BOs and recommend any necessary changes.
Prior to the listing of salmonid ESUs under the ESA, the majority of
salmon conservation efforts were conducted by individual states, tribes, and private
industries that managed salmon habitat. In the Columbia River Basin, the Northwest Power
Planning 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. Subsequently, federal agencies and public utilities spent hundreds of millions
of dollars on technical fixes for dams, habitat enhancement, and water purchases to
improve salmon survival, yet many populations have continued to decline. Recent years have
seen an increased interest by state governments and tribal councils in developing
comprehensive salmon management efforts. States generally seek to prevent 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 among federal, state, and tribal agencies as a powerful and
necessary tool in saving listed salmonid species, as well as possibly avoiding the need
for future listing of additional ESUs through state-managed comprehensive recovery
efforts.(11) NMFS views 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 recent 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.(12) 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, such as a "three sovereigns" approach involving
equal partnerships among 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).
In June 1997, the U.S. Fish and Wildlife Service released a draft plan, including 100
measures such as fish screens, fish ladders and water pollution reduction, to double by
2002 the native fish populations in the Central Valley Project area.
NMFS has issued an interim policy on artificial propagation of
Pacific salmon under the ESA to provide guidance on how hatcheries should be used to help
recover salmonids.(13) 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 have
instituted programs to 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 anticipated or
are underway for other species, such as chinook salmon and steelhead trout. In addition,
controversy and resistance remain over suggested changes to using fishing gear more
suitable to releasing wild fish caught inadvertently.
The bilateral 1985 Pacific Salmon Treaty regulates the harvest of
salmon of U.S. and Canadian origin. While the Treaty calls for reducing interceptions of
the other country's fish, it also calls on the parties to avoid undue disruption of
existing fisheries. However, ESA protective measures, including the prohibition against
taking ESA-listed fish and the designation of critical habitat, could be undercut by U.S.
and Canadian fishermen catching ESA-listed fish as they migrate through Alaskan and
Table 1: Status of Six Species of Pacific
|1. Central California....................................
||1. 61 FR 56138 Oct. 31, 1996
|2. Southern Oregon/Northern CA coasts.....
||2. 62 FR 24588 May 6, 1997
|3. Oregon Coast...........................................
||3. 63 FR 42587 Aug. 10, 1998
||Complete final critical habitat designation by early 2000
|4. Puget Sound/Strait of Georgia.................
||4. 60 FR 38001 July 25, 1995
||Complete listing assessments for candidate ESU
|5. Southwest WA/Lower Columbia River....
||5. 60 FR 38001 July 25, 1995
|1. Sacramento River winter-run...................
||1. 55 FR 12832 Apr. 6, 1990
||Develop proposed 4(d) rules for threatened ESUs
Complete final critical habitat designations for listed ESUs by early 2000
||55 FR 49623 Nov. 30, 1990
||59 FR 13836 Mar. 23, 1994
|2. Snake River fall-run.................................
||2. 57 FR 14653 Apr. 22, 1992
|3. Snake River spring/summer-run.............
||3. 57 FR 14653 Apr. 22, 1992
|4. Central Valley spring-run........................
||4. 64 FR 50393 Sept.16, 1999
|5. Upper Columbia River spring-run...........
||5. 64 FR 14308 Mar. 24, 1999
|6. California coastal....................................
||6. 64 FR 50393 Sept. 16, 1999
|7. Puget Sound.............................................
||7. 64 FR 14308 Mar. 24, 1999
|8. Lower Columbia River............................
||8. 64 FR 14308 Mar. 24, 1999
|9. Upper Willamette River...........................
||9. 64 FR 14308 Mar. 24, 1999
|10. Central Valley fall and late-fall run.......
||10. 64 FR 50393 Sept. 16, 1999
|1. Hood Canal summer-run..........................
||1. 64 FR 14508 Mar. 25, 1999
||Complete final critical habitat designations for both
listed ESUs by early 2000
Develop proposed 4(d) rules for threatened ESUs
|2. Columbia River.......................................
||2. 64 FR 14508 Mar. 25, 1999
|1. Snake River..............................................
||1. 56 FR 58619 Nov. 20, 1991
||Complete final critical habitat designations for listed ESU by
|2. Ozette Lake..............................................
||2. 64 FR 14528 Mar. 25, 1999
||Develop proposed 4(d) rules for Ozette Lake ESU
|1. Southern California..................................
||1. 62 FR 43937 Aug. 18, 1997
||Complete final critical habitat designations for listed
ESUs by early 2000
Develop proposed 4(d) rules for threatened ESUs
|2. South-Central California Coast................
||2. 62 FR 43937 Aug. 18. 1997
|3. Central California Coast..........................
||3. 62 FR 43937 Aug. 18. 1997
|4. Upper Columbia River.............................
||4. 62 FR 43937 Aug. 18. 1997
|5. Snake River Basin....................................
||5. 62 FR 43937 Aug. 18, 1997
|6. Lower Columbia River.............................
||6. 63 FR 13347 Mar. 19, 1998
|7. Central Valley..........................................
||7. 63 FR 13347 Mar. 19, 1998
|8. Upper Willamette River...........................
||8. 64 FR 14517 Mar. 25, 1999
|9. Middle Columbia River...........................
||9. 64 FR 14517 Mar. 25, 1999
|10. Northern California................................
||10. 63 FR 13347 Mar. 19, 1998
||Complete listing assessments for candidate ESUs
|11. Klamath Mountains Province.................
||11. 63 FR 13347 Mar. 19, 1998
|12. Oregon Coast..........................................
||12. 63 FR 13347 Mar. 19, 1998
|Sea-run cutthroat trout
|1. Umpqua River (Oregon)..........................
||1. 61 FR 41514 Aug. 9, 1996
|2. Southwest Washington/Columbia River..
||2. 64 FR 16397 Apr. 5, 1999
||Complete final listing determinations for
Southwestern WA/Columbia River ESU by April 2000
|3. Oregon Coast ..........................................
||3. 64 FR 16397 Apr. 5, 1999
||Complete listing assessment for candidate ESU
Winninghoff. "Where Have All the Salmon Gone?" Forbes (Nov. 21,
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.
of table information: U.S. Dept. of Commerce, National Marine Fisheries Service,
"Progress of Species Status Reviews in NMFS Northwest & Southwest Regions" (http://WWW.NWR.NOAA.GOV/1salmon/salmesa/index.htm,
updated Apr. 1, 1999).
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, November 20, 1991).
Nehlsen, Jack Williams, and James Lichatowich. "Pacific Salmon at the Crossroads:
Stocks at Risk from California, Oregon, Idaho, and Washington." Fisheries,
v. 16 (1991):4-21; and T.L. Slaney, et al. "Status of Anadromous Salmon and Trout in
British Columbia and Yukon." Fisheries, v. 21 (Oct. 1996): 20-35.
spilled from dams can become supersaturated with gaseous nitrogen. Fish exposed to
supersaturated conditions can develop disorienting and harmful gas bubble disease.
7. (back)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.
the Columbia Salmon," Seattle Times (June 8, 1997): B4-B6.
Stern, Jr. "Supplementation of Wild Salmon Stocks: A Cure for the Hatchery Problem or
More Problem Hatcheries?" Coastal Management, v. 23 (1995):123,
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.
communication with Garth Griffin, Branch Chief, Protected Resources Division, NMFS,
Portland, OR, on May 21, 1998.
Natural Resources Council v. Daley, CV-97-1155-ST (D.Or. June 1, 1998).
13. (back)58 Federal
Register 17573, Apr. 5, 1993.