Report Card45% of Oregon's freshwater fish have declined and are at risk of extinction. (Oregon is ranked fifth among thestates in terms of the greatest number of listed fish species.)

Approximately 60% of native fish in the lower Willamette exhibit external abnormalities.

Localized (endemic) populations of suckers and chubs in southern Oregon are fragmented and many havedeclined in recent years.

More than 32 species of freshwater fish have beenintroduced into Oregon and are now self-sustaining, making up approximately one-third ofOregon's freshwater fish fauna.

Key Indicator1. Proportion of the percentage of wild, native fish

populations, including salmon, that are classifiedas healthy.

3.6 Summary of Current Statusand Health of Oregon's

Freshwater Fish CommunitiesStan Gregory

Professor, Department of Fisheries and Wildlife, OSU

IntroductionFish have played a central role in the history and economy ofOregon. Many have said that the Pacific Northwest is definedas "anywhere the salmon go". Our regional identity is closelytied to salmon, which link the land, rivers, and Pacific Ocean.Fish serve as indicators of healthy, functioning ecosystems,economically healthy resource-based industries, cultural val-ues of Native Americans and recent Oregonians, recreationopportunities, and the livability of our communities. Theimportance of fish and the fundamental need to protect thisresource are rarely questioned by the public.

Definitions of healthy fishcommunitiesThe health of Oregon's fish communities can be describedfrom all three perspectives of health developed in this report:naturally functioning systems, sustainable productivity, andcompliance with laws and policies. A fundamental definitionof a healthy fish resource is naturally functioning populationsthat can maintain their abundance, composition, distributionacross the landscape, and ecological functions in the face ofunpredictable disturbances and environmental change with-out continued human intervention. From an ecological per-spective, healthy fish populations maintain their abundance

despite environmental change and episodic disturbances. Thegeographic range of healthy species does not shrink. Healthyfish communities are composed primarily of native species,and species introduced from other regions are not dominant.Lesions, tumors, and deformities are rare. Healthy fish popu-lations provide critical ecosystem functions, such as structur-ing food webs through predation and competition and sup-plying nutrients from other ecosystems. Migratory species,such as salmon and steelhead, transport important nutrientsfrom marine ecosystems to both freshwater and adjacent ter-restrial ecosystems. Fish populations often reflect the effectsof many land uses, pollutants, habitat conditions, and thusserve as valuable indicators of environmental conditions.

Considering the second perspective of health, thesustainability of resource uses, healthy fish resources are self-sustaining populations that are sufficiently abundant and welldistributed to meet cultural values and economic needs. Fishare an important component of Oregon's economy, support-ing commercial fishing, coastal charter sport fishing, fishingin inland streams and lakes, sporting goods, and resorts.Healthy fish stocks are able to support some level of harvestand still maintain self-sustaining populations.

Chapter III ♦ Health of Natural Systems and Reso

(.0

e 44r 4, is* 0. 44' dib 4kr 41/4

Source: U.S. Fish & Wildlife Service website of current listed species: http://www.endangeredspecie.com

Fish represent a difficult challenge for resource managementand community-based decisions about resource use. Land usesor environmental degradation in one portion of the state cancause declines in migratory fish and result in economic im-pacts on communities far from the cause of the decline. Localcommunity decision-making processes cannot effectively in-fluence the decisions that lead to the resource impacts. Thus,regional conservation strategies are essential frameworks formanaging fish resources.

Ecosystem health from the perspective of meeting legal stan-dards applies to fish resources because they are protected un-der numerous federal and state laws. These regulations aredesigned to protect fish populations as both ecosystem com-ponents and resource commodities. Commercial and sportfishing are protected by state regulations and regional com-missions. State laws are designed to protect Oregon's biologi-cal diversity. Regardless of debates about their effectiveness,these regulations can be used as measures of fish resourcehealth in terms of numbers of protected species, level of al-lowed harvest, and legislated protection.

IndicatorsOne of the most important indicators of the health of fish inOregon is the proportion of salmon and other fish popula-

tions that are classified as healthy in each ecoregion. A directmeasure of the health of fish species is its abundance andgeographic distribution. Statewide assessments for all fish spe-cies are not available because of the extraordinary effort re-quired to measure abundance or distribution. Oregon Depart-ment of Fish and Wildlife is renewing its recurring assessmentof Health of Native Fish Populations in Oregon. This assess-ment could be revised to 1) be spatially explicit, 2) incorpo-rate distributions of fish species throughout each ecoregion,and 3) incorporate existing data on population trends andformal considerations for listing. This approach would requiredevelopment of a scientifically sound measure of the pres-ence and absence of fish species throughout each ecoregion.The indicator would be the proportion of the populations orstocks that are healthy (not declining or at risk), and the statewould expect the proportion of healthy populations to bemaintained or increased in the future.

This indicator and measurement approach would provide sev-eral additional pieces of information. Examples would includeproportions of exotic fish species, proportions of fish that arediseased or deformed, presence of species at risk, and relativeabundances of salmonids.

The level of harvest allowed for both commercial and sportfishing is one measure of sustainable production of resources.

Figure 3.6-1. Number of fish species federally listed as threatened or endangered as of May 2000

60 ♦ Oregon State of the Environment Report

Fishing limits are socially meaningful because they are a di-rect measure of the stocks that Oregonians consider to behealthy. Harvest limits are insensitive to short-term changesin abundance because they also are determined by economic,political, and social objectives. Historically, harvest levels rarelyhave been adjusted until major declines in fish populationsare detected.

A major legal indicator of the status of fish populations inOregon—extinctions and threatened or endangered listings—provides an extreme but meaningful measure of Oregon'senvironment. Unfortunately, this indicator of fish health rarelyserves as an early warning system, but rather indicates theneed for extremely protective measures to prevent completeloss of species or stocks.

Current conditions and trendsSixty-three species or recognized subspecies of native fresh-water fish are found in Oregon. Currently, 14 of those speciesor subspecies are listed under the Endangered Species Act asthreatened or endangered (ODFW 1995). An additional 15species are listed as candidate species and their status is beingevaluated (Table 3.6-1). This means that 45% of Oregon's

freshwater fish are at risk of extinction or have declined tolevels that warrant state or federal efforts to protect them.Oregon ranks fifth in terms of the greatest number of listedfish species in a comparison of fish species that are federallylisted as threatened or endangered throughout the UnitedStates (Figure 3.6-1).

Five of the species that are listed are salmon or trout, andthey include 22 genetically distinct populations or stocks thatare listed as threatened, endangered or candidates for listing.A review of salmon stocks throughout the Pacific Northwestindicated that 214 stocks face significant risk of extinction(Nehlsen et al., 1991). Since that review, none of the stocks atrisk have been shifted to a more stable category, but 12 addi-tional stocks of salmon have been federally listed as threat-ened or endangered. Numbers of anadromous fish migratingover falls or barriers, such as Willamette Falls, Winchester Dam,Bonneville Dam and others, have declined sharply over thelast several decades. In response to concerns about the healthof these salmon populations, commercial and sport harvesthave been sharply curtailed and fishing for coastal cohosalmon was eliminated entirely from 1994 to 1998.

Table 3-6-1. Native species of Oregon freshwater fish and their status under federal and state legislation.SpeciesGreen sturgeonWhite sturgeonChiselmouthBridgelip suckerLargescale suckerSacramento sucker

Sacramento sucker spMountain suckerKlamath smallscale suckerJenny Creek sucker

Klamath largescale suckerTahoe suckerWarner suckerShortnose suckerCoastrange sculpinPrickly sculpinMottled sculpin

Malhuer mottled sculpinPiute sculpinShorthead sculpinRiffle sculpinMarbled sculpinMargined sculpinReticulate sculpinPit sculpinKlamath Lake sculpinTorrent sculpinSlender sculpin

Federal status

Candidate

CandidateCandidate

Threatened

Candidate

Candidate

Candidate

Candidate

State status

Sensitive—critical

Sensitive—naturally rare

Sensitive—peripheralThreatened

Sensitive—critical

Sensitive—vulnerable

Sensitive—peripheral

Chapter III ♦ Health of Natural Systems and Resoucce3

Table 3-6-1. Native species of Oregon freshwater fish and their status under federal and state legislation(continued).Species Federal status State statusShiner perchLost River sucker Endangered EndangeredThree-spined sticklebackAlvord chub Candidate Sensitive—vulnerableTui chub

Catlow tui chub Candidate Sensitive—vulnerableGoose Lake tui chub Sensitive—criticalHutton Springs tui chub Threatened ThreatenedOregon lakes tui chub Candidate Sensitive—vulnerableSheldon tui chub Candidate Sensitive—criticalSummer Basin tui chub Candidate Sensitive—criticalWarner Basin tui chub Sensitive—critical

Borax Lake chub Endangered EndangeredBlue chubCalifornia roach Candidate Sensitive—peripheralRiver lampreyPit-Klamath brook lampreyMiller Lake lampreyWestern brook lampreyLampetra similisPacific lamprey Sensitive—vulnerable

Goose lake Pacific lamprey Sensitive—criticalBurbotPeamouthLahonton cutthroat trout Threatened ThreatenedPink salmon Endangered EndangeredChum salmon ThreatenedCoho salmon Threatened EndangeredRainbow troutSteelhead Threatened Sensitive—criticalRedband trout Petitioned

Sockeye salmonChinook salmon Threatened ThreatenedOregon chub Endangered EndangeredUmpqua chub Candidate Sensitive—vulnerableSand rollerStarry flounderMountain whitefishNorthern pikeminnowUmpqua pikeminnowLongnose dace

Millacoma dace Sensitive—naturally rareUmpqua daceLeopard daceSpeckled dace

Foskett speckled dace Threatened ThreatenedRedside shiner

Umpqua redside shiner Sensitive—peripheralLahonton redside shiner

Bull trout Threatened/Endangered SensitiveEulachon

62 ♦ Oregon Stale of the Environment Report

Though not as highly publicized as anadromous salmon, lo-calized (endemic) populations of suckers and chubs in south-ern Oregon are fragmented and many have declined in re-cent years. Such populations are inherently vulnerable becauseof their isolated and patchy distributions. Combined effectsof water withdrawal and drought conditions over the last de-cade have caused several populations to decrease and raiseconcerns over their survival.

Occurrence of tumors, lesions, and deformities in fish is a di-rect measure of fish health that is closely related to humanhealth and environmental contamination. Major concernshave been raised about the high proportion of open lesions,tumors, and skeletal deformities in largescale sucker and north-ern pike minnow in the lower Willamette River near Port-land. Skeletal deformities comprised less than 5% of the fishsampled upstream of Corvallis, increased to 20% betweenCorvallis and Newberg, and exhibited the highest incidence(56%) in the Newberg Pool (Ellis et al., 1997). Studies by Or-egon State University researchers in 1998 found that less than20% of the fish in the upper Willamette River exhibited someform of external abnormality in contrast to 60% of the fishwith external abnormalities in the lower Willamette.

Another indicator of stress on native fish communities is theproportion of fish species introduced from other regions. Morethan 32 species of freshwater fish have been introduced intoOregon and are now self-sustaining, making up approximatelyone-third of Oregon's freshwater fish fauna. Most of theseintroductions have been intentional, primarily for sport fish-ing. Others, like grass carp and mosquito fish, were introducedfor biological control. Introduced species are predators onnative species, compete for food resources, and alter freshwa-ter habitats. In 1998, researchers at OSU found that introducedfish comprised less than 5% of the number of species foundin the upper Willamette River near the McKenzie River butaccounted for more than 60% of the observed species in thelower river near Portland. Introductions of predators, such asbass and other sunfishes, have been identified as one of themajor causes for the decline of Oregon chub in the WillametteRiver and Umpqua chub in the Umpqua River.

Causes of trendsIdentification of the causes for declines of fish populationshas been one of the most divisive debates in the Pacific North-west in the latter half of the twentieth century. Relative im-pacts of different factors, both human action and natural en-vironment, differ by species, historical period, and geographiclocation. Freshwater and estuarine habitats have been affectedby timber harvest, livestock grazing, agriculture, water with-drawal, urbanization, and mining. Commercial fishing andsport fishing have caused major declines. Hydroelectric de-velopment has altered freshwater habitat and created se-

quences of barriers for both young and adult migrating fish.Hatchery operations have altered the genetic composition ofsalmonid stocks and changed the timing of their migrations.Use of hatcheries when wild fish numbers are low encouragescontinued impacts on the declining populations and can beextremely detrimental. Predation by marine mammals, birds,and introduced fish species can be locally intense pressureson declining populations, and the impact of predation is ex-acerbated by habitat simplification that make such predatorsmore effective. Natural shifts in climate, such as recent warm-ing trends related to El Nino events, have stressed popula-tions and amplified the detrimental effects of human impacts.

ThreatsThe severity and magnitude of many of these human sourcesof degradation and stress were largely uncontrolled in the late1800s and early 1900s. Though many regulations now attemptto protect fish, freshwater habitats continue to be affected bylogging, livestock grazing, water withdrawal, agriculture, min-ing, and urbanization. One of the major challenges to revers-ing trends in habitat degradation is the unevenness of landuse laws and regulations. Riparian practices on both publicand private forest lands are controlled to a much greater de-gree than on range, agricultural, or urban lands. Ecologicaland environmental protections asked of forest land managersare not asked of agricultural and urban land owners. Manage-ment practices in riparian and stream habitats on agriculturallands and urban areas in the future are highly uncertain. Onemajor difference between agricultural and urban lands is thatmost agricultural practices are reversible in the future, butmany changes in urban and residential areas are much lessreversible.

Consequences of water quality for fish communities will con-tinue to be a major concern, particularly with respect to wa-ter temperature and toxic contaminants. Lack of riparian pro-tection on urban, agricultural, and range lands will continueto raise questions about attainable stream temperatures, par-ticularly in lowland streams and large rivers. The numbers ofstreams that fail to meet water quality standards are likely toincrease as better data become available through improvedwater quality monitoring. Many of the extreme water pollu-tion sources of the past—sewage, food processing wastes, pulpmill wastes, thermal discharges—are scrutinized by point-source discharge permit requirements of environmental agen-cies. The major challenge will be understanding and control-ling highly toxic substances at low concentrations and iden-tifying new types of toxic industrial pollutants. With greaterurban and industrial development, concerns about fish health,including lesions, tumors, deformities, will likely increase.

Harvest, either commercial or sport, will always pose a risk todepressed fish populations. The desire to catch fish is always

Chapter III ♦ Health of Natural Systems and Resources • 63

great, and politicians and managers are reluctant to decreasethe public's access to fish resources. Most changes come aftersevere declines have already occurred. Recent regional fisherymanagement has moved toward more conservative measuresthan historical harvests.

Introductions of exotic fish that compete with or excludenative species have largely been ignored by the public and areoften applauded in the name of sport fishing or biologicalcontrol. Ranges of introduced species are likely to expand andnew species will be introduced. For example, smallmouth bassare voracious predators and are increasing in the Willametteand Columbia River systems. Their impacts on native speciesare poorly understood. Potential dangerous non-indigenousspecies, such as zebra mussels, have been found in neighbor-ing states and the risk of introduction in Oregon is high.

StrengthsThe status of fish communities in Oregon is strengthened bythe large public land base, wilderness areas in mountainousparts of the landscape, major regional conservation plans, andintense public concern about public resource management.These factors directly affect species in mountainous landscapesbut are less relevant for species in lowland rivers and streams.Intense public concern about fish resources is a strength ofOregon, and its influence on the future status of fish is uncer-tain but important.

at data are available and howcomplete are they?Major data sources for fish populations in Oregon are 1) dis-tributional data, 2) abundance of migratory species over damsor through ladders, 3) spawner surveys, 4) commercial catch,5) habitat surveys, and 6) fish population models. Many ofthese databases, such as the spawner surveys are statisticallyreliable and provide time trends. Other data, such as passage

numbers, are credible for specific locations. The state has in-vested heavily in freshwater habitat surveys in recent yearsand this knowledge base is improving. The lack of any state-wide comprehensive monitoring program to systematicallytrack the status of representative, widely distributed species isa major deficiency.

What more do we need tounderstand?Most of our knowledge of fish populations deals with anadro-mous salmon and trout and species in forested habitats. Popu-lation status and habitat relationships in lowland streams andlarge rivers are extremely poorly understood. Given the obvi-ous human population increases and development of low-lands, increased attention to these landscapes is critical.

Relationships between toxic contaminants and health of bothfish and human communities are extremely important forOregonians and are poorly understood. With increasing ur-banization and industrial development, better understandingof the sources, consequences, and potential solutions is es-sential.

ReferencesEllis, S.G., S.T. Deshler, and R. Miller. 1997. Characterizing

fish assemblages in the Willmaette River, Oregon, usingthree different bioassessment techniques. Pages 347-366.In: A. Laenen and D.A. Dunnette (eds.). River Quality:Dynamics and Restoration. CRC Press, New York.

Nehlsen, W., J. E. Williams, and J. A. Lichatowich. 1991.Pacific salmon at the crossroads: stocks at risk fromCalifornia, Oregon, Idaho, and Washington. Fisheries 16:4-21.

Oregon Department of Fish and Wildlife. 1995. Biennialreport on the status of wild fish in Oregon. Portland,Oregon. 272 p.

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