Engihs& Re•d:Wetland restorationchallenges

Challengesin wetland restorationof the western

Andrew Engilis,Jr. & FredericA. Reid

Engilis,A., Jr.,and F. A. Reid. 1996.Challenges in wetlandrestoration of thewestern Great Basin. International Wader Studies 9: 71-79. WesternGreat Basin wetlands are recharged by surfaceand underground runoff from mountains. Evapotranspirationis the onlymechanism that drains Basin wetlands. Surface modifications to interceptrunoff and ground water are the greatest impact to theBasin's wetlands. Restoration of wetlandsin the Basinshould start with a clearunderstanding of the site'shydrology, soil, and topography.Wetland managers should have goals and objectives for eachrestoration project and shouldensure that adequatewater is availableto achievethose goals. Restoration techniques used in the Basinare summarized,including the creationof dikedwetlands, excavation strategies, nest islandcreation, restoration of moist-meadowhabitats, and controlof alienorganisms such as tamarix(Tamarix spp.), loosestrife (Lythrum salicaria), and carp (Cyprinuscarpio). AndrewEngilis, Jr., Ducks Unlimited, Inc., Western Regional Office, 3074 Gold Canal Dr., RanchoCordova, CA 95670 USA FredericA. Reid,Ducks Unlimited, Inc., Western Regional Office, 3074 Gold Canal Dr., RanchoCordova, CA 95670 USA

Introduction In thispaper we summarizethe hydrologic uniquenessof thewestern Great Basin, past and modernimpacts to the wetlands,and offer The geologicsetting of theGreat Basin accounts for techniquesto restore,protect, and managethis the many termsused to describethe region: critical continental resource. To understand wetland IntermountainBasins, Basin and RangeCountry, restoration,it is importantto firstcomprehend the SagebrushDesert, High MountainDesert, and "The dynamicsof the regionalhydrology. Restof the West." All conjureimages of a desolate openexpanse with little humanhabitation. Wetlands are rarelymentioned as an attributeof thewestern GreatBasin (Basin), yet the Basinsupports a diverse Hydrology of westernGreat Basin wetlands systemof pluvial lakes,playas, marshes, and riparianhabitats. Forty-five modern valley lakes occur in the western and central Great Basin, How western Great Basin wetlands function is covering1,001,345 ha (Grayson1993). Theselakes criticalto understandingwhat techniquesmight be supportover 640,000ha of marshes,playas, and employedfor restorationand protection.Three riparian habitats, many critical to thelife history factors,1) locationand size of mountains,2) needs of North American shorebirds. precipitationrates, and 3) evapotranspitrationrates accountfor the high numberof lakesand wetlands Althoughthe Basin'swetland acreage seems high, north of the 40thparallel, and lackof wetlandsto the particularlyfor an arid region,it is moreimportant to examine where wetlands are located in relation to south(Figure 1). ongoingefforts to protectand restorethem. Characterizedas a high-altitude,cold desert, the Effects of mountains diversityof Basinhabitats makes the regionone of the world's mostbiologically diverse desert ecosystems.Numerous north-south oriented The westernGreat Basinis dissectedby numerous mountainranges divide the western Great Basin into north-southmountain ranges, 33 of which have a seriesof smaller,isolated basins fed by over 200 peaksthat exceed3,000 meters elevation (Grayson drainages.The longestdrainage is the Humboldt 1993). The importanceof thesepeaks in driving the River, , which beginsin the easternBasin and Basin'shydrology and locationof wetlandsis terminatesin the HumboldtSink. Otherlarge underscoredby the occurrenceof the Humboldt drainagesand basinsoccur along the easternflank of Riversystem. The Humboldt River is the largest the SierraNevada-Cascade range. watershed within the Basin. Its headwaters are in high mountainranges where rainfall exceeds40 cm The westernGreat Basin is sparselysettled relative to annually(Figure 2). other interior regionsof the . Nevertheless the Basin's wetlands are under Elsewherein the watershed,annual rainfall averages numerousthreats from development,ground and 20 cm. The size of theseranges are small by surfacewater diversions,and hydroelectricprojects. comparisonwith the SierraNevada and Rocky

71 Internatzonal Wader Studies 9. 71-79

lOO ID

NV 125

UT

200-- 0o'o06o

160

PRECIPITATION (cm) KM

200 -/ E. T. * LINES

WETLAND BASINS

Figure 1. Terminalwetland habitatsof the westernGreat Basin in relationto precipitationand evapotranspiration(E.T.).

Mountains,but combined,they dominatethe Basin patternsof the westernand northernBasin between as geologicfeatures. The front rangesthat rim the Octoberand April. Continentaland Gulf storms Basinare associatedwith the largestwetland impactthe mountainsof the easternBasin and complexes(Figure 1). The easterndrainages of the accountfor 50%of totalregional rainfall (Grayson SierraNevada support229,764 ha of lakes 1993). In betweenthese large storm systems, rainfall (dominatedby Mono, Tahoe,Pyramid, and Honey totalsrange from 10 cm to 30 cm (Figure2). Patterns lakes),and the easterndrainages of the Cascades of rainfallwithin thewestern Great Basin are greatly support415,536 ha (dominatedby Abert,Klamath, affectedby orthography,with rangescreating rain Goose,and Summer lakes). At 20,000ha, Malheur shadowson theirlees. The front ranges intercept the Lake (actuallya marsh)is the largestinland lake not majorityof precipitation.The SierraNevada connectedto the threefront rangesthat rim the Basin interceptsmost rainfall from westerly low-pressure (Duebbert1969). Althoughlake valleysare more systemscreating a gradientof 150cm per year in the permanentin their water features,numerous playas DesolationWilderness, to 20 cm per year and sinksalso provide important waterbird habitat, in CarsonCity, Nevada, a distanceof 40 km particularlyfor nestingshorebirds. Some of these (Durrenberg& Johnson1976). Typicallythe crestof playasflood and dry on annualcycles (Humboldt front rangesoften exceed 75 cm of precipitationper and Carson,Nevada), while othersonly periodically year (Figure1). Thisprecipitation generally falls as flood (RailroadValley, Nevada). snow and the resultingmelt watersaccount for the majorityof wetlandsalong the front ranges (Figure 1). Another characteristic of Basin wetlands and lakes is Precipitation patterns that all are terminal,with no drainageto the ocean. In general,these sinks are fed by surfacerunoff, The positionof mountainranges and how they which canaccount for up to 80% of the lake and interceptand deflectPacific and Continental wetlandrecharge in a givensystem (Hoffman 1994). generatedstorms drive the hydrologyof the western However,many of theBasin marshes are equally Great Basin. Pacific storms dominate weather impactedby groundwaterrecharge and not surface

72 Engihs& Reid:Wetland restoration challenges runoff. For example,Ruby Marsh, in the eastern degreeof precipitationfrom the previoussnow Great Basinof Nevada, is annually dependentupon season.In wet years,numerous shallow basins groundwater, flowing from at least25 artesian flood,but in droughtyears, relatively large playas springsthat surfacealong the eastern base of the might dry. Thesepatterns of wet and dry periodsare RubyMountains (Wilson 1986). dramaticand unpredictable.For example,since hydrologicrecords were startedin 1938,Malheur Lake, Oregonhas ranged in size from 26,800ha Evapotranspiration (1952) to 2,800ha (1962). In 1934, Malheur Lake was dry and farmed. By 1938the lake had reached17,200 Sincebasins have no outlets,evapotranspiration is ha (Duebbert1969). Even more permanentlakes theonly mechanism (other than diversions by such as Lake Abert (14,600ha) and Goose Lake humans)that "drains" its marshes. (38,960ha) have beendry in the recentpast (Grayson Evapotranspirationrates in the Basinare among the 1993). In the mid-1980s numerous lakes in the Basin highestin North America,but vary greatlyfrom floodedto their highestlevels recorded. By the early north to south. Averageevapotranspiration rates in 1990s,drought greatly impacted many Basinlakes. the north arebetween 86 - 112cm per year,and in the southbetween 140 - 215 cm per year (U.S.Dept. of Shorebird habitat in western Great Commerce1983). Higher temperaturesaccount for the higherrates in the south. Most of the Basin's Basin wetlands wetlands and lakes occur north and west of an evapotranspirationrate of the 125cm per year The importanceof Basinwetlands to shorebirdshas evapotranspirationline (Figure1). beendiscussed in previouschapters. In addition to Basinlakes and marshesexperience hydrologic the high diversityof shorebirds,Basin wetlands fluctuationsduring an annualcycle and among accountfor oneof the world's mostunique systems years. Variabilityis directlyassociated with the of biota. During the late Pleistocene,Basin wetlands

-L

r I r I

r- I

r•

A

PRECIPITATION 10 cm

20 cm 160

30 cm KM HUMBOLDT WATERSHED WETLANDBASINS

Figure2. Locationof HumboldtRiver systemin relationto rainfallpatterns.

73 International Wader Studies 9:71-79

were part of a largesystem of pluvial lakes. During Impacts to western Great Basin its peak, the Basinheld 11,120,000ha of lakesand wetlands wetlands;however, climatic changes have reduced this acreage90% (Grayson1993). Inhabitedby numerousinvertebrates, fishes, amphibians, and Understandingthe threatsand degradationsthat other terrestrialvertebrates, major radiationsof impactthese wetlands are critical prior to initiating speciesresulted from recurrentisolation events that restoration efforts. Several authors have were createdby sequentialdrying periods. Thereare summarizedthe impactson Great Basinwetlands no speciesendemic to the Basin,although there (Kadlec & Smith 1989;Ratti & Kadlec 1992;Jehl 1994; are numerousspecies associated primarily with this DucksUnlimited 1994). Many of the modernland region (Ryser1985). Most avian speciesare uses in the Basin are inconsistent with historic associatedwith the sagebrushand sagebrush-steppe hydrologicpatterns of floodingand drought,and so communitiesof thebasin floors and pinyon-juniper degradationhas occurred rapidl}a The Reclamation woodlands of the mountains. Act of 1902was the primaryvehicle for the beginningof modificationsto Basinwetlands. Basinwetlands are of primary importanceto Attemptsto harnesswater resources,both surface numerousspecies of waterbirds.For example,the runoffand groundwater,were carried out in orderto LahontanValley provides habitat for thewidest minimizeflooding and droughtimpacts, particularly diversityand largestpopulations of migratoryand duringperiods of climaticextremes (Hoffman 1994). wetland dependentwaterbirds in Nevada (USFWS Thesemodifications have resulted in systemsthat 1994;Jehl 1994; Page & Gill 1994). Althoughthe oftenneed human-induced management of wetlands Basinwetlands have beenrecognized as importantto in certainkey marshhabitats within the Basin numerousspecies of nestingwaterbirds, dominated (Kadlec & Smith 1989). by ducksand shorebirds,they are alsoa critical stagingand migratoryarea for continentalresources Surfacemodifications to interceptprecipitation and of shorebirdsand waterfowl (Kadlec& Smith 1989; snow-meltrunoff have resulted in thesingle greatest Ratti & Kadlec1992; Jeh11994). This regionis of impactto Basinmarshes. Water diversionfor globalimportance for numerousnesting shorebirds agricultureaccounts for 84%of diversionsin Nevada (Oring & Reed,this volume),including: Black- (Hoffman 1994). The water area of the CarsonBasin, neckedStilt (Himantopusmexicanus), Snowy Plover Nevadawas nearlypermanent during the 1800s, (Charadriusalexandrinus), Long-billed Curlew encompassing80,000 ha (Hoffman1994). Waterwas (Numeniusamericanus), and Willet (Catoptrophorus divertedin 1902to manage5,600 ha of irrigated semipalmatus).Basin wetlands are alsoof continental agriculturallands, and by 1990,23,200 ha were under importancefor numerousother waterbirds (Table 1). management(Hoffman 1994). During the droughtof The importanceof Basinwetlands thus cannot be 1986- 1992,water was divertedfor agricultureand overlookedas a criticallink amongcontinental urbanuse at theexpense of wetlands.Stillwater resources.Restoration and managementof NationalWildlife Refuge,Carson Lake, and Carson remainingwetland landscapesshould be a priority. Sinkwere nearly dr)5 accounting for only240 ha of

Table1. Breedingwaterbirds of westernGreat Basin (Sources: AOU 1983,Ryser 1985, Page and Gill 1994).

Primary Importance SecondaryImportance Minor Importance Largeportion of continental breeding Morewidespread, but Basin marshes Presentas breeding species, but populationwithin the Basin importantto westernU.S. populations widespreadacross the continent

White-facedIbis Plegadischihi EaredGrebe Podoceps nigricollis Pied-billedGrebe Podilymbus podiceps

Canada Goose Branta canadensis SnowyEgret Egretta thula Double-crested Cormorant Phalacrocorax auritus CiimamonTeal Anas cyanoptera Grus canadensis American Bittern Botauruslentiginosus American Avocet Recurvirostra americana Gadwall Anasstrepera Black-crownedNight-Heron Nycticoraxnycticorax Black-necked Stilt TrumpeterSwan Cygnus buccinator Green Heron Butorides striatus SnowyPlover Ruddy Duck Oxyurajamaicensis Great Blue Heron Ardea herodias Long-billedCurlew CanvasbackAythya valisineria Mallard Anasplatyrhynchos CaliforniaGull Laruscalifornicus Redhead A. american Green-wingedTeal A. crecca Willet AmericanWigeon A. americana Wilson'sPhalarope Phalaropus tricolor Northern Pintail A. acuta Franklin'sGull Laruspipixcan NorthernShoveler A. clypeata Ring-billedGull L. delawarensis Blue-wingedTeal A. discors Forster'sTern Sternaforsteri Ring-neckedDuck A. ythya collaris BlackTern Chlidonias niger LesserScaup A. affinis CaspianTern, S. caspia VirginiaRail Railuslœmicola Sora Porzana carolina American Coot Fulica american KilldeerCharadrius vociferus SpottedSandpiper Actitis macularia CommonSnipe Gallinago gallinago BeltedKingfisher Ceryle alcyon Engilis& Reid:Wetland restoration challenges wetlands in 1992 (Alberico 1993;Hoffman 1994). In reproducequickly and completelychoke out shallow the Klamath Basinof Oregon/California, diversions wetlandsand rivers. Onceestablished in waterways, prior to 1900to controlflooding resulted in a decline the tree'sdispersal strategy, which is to sendout from 140,000 ha of wetland to 14,000 ha in the late numerous,tiny seeds,quickly infests ponds and 1980's (USFWS 1989). streamsideriparian habitats. Managers are often forcedto forgocertain water sources or completely In additionto water diversions,water quality dry out pondsin an attemptto controltamarisk. degradationscontinue in the Great Basin. Dams on the Carson, Walker, Humboldt, and Bear rivers have Unfortunately,the conditionsfor shorebirdspring greatlyimpacted wetlands in terminalbasins. migrationare low water levelsand tackymudfiats, a conditionsuited for tamariskregeneration. As such, Livestockmanagement is of paramountconcern becauseof traditionalgrazing on publiclands. areasthat aremanaged for shorebirdsare usuallythe Livestock are attracted to streams and marshes, first to becomeovergrown. contributingto lower water quality and habitat degradation(Heitmeyer 1991). Bankerosion caused Restoration of western Great Basin by livestockalong smaller streams can be severe. wetlands Waterquality issuesin marshesare further complicatedas mostterminal basins today receive return water from agriculturallands that can lead to Wateravailability is the limitingfactor for most nutrientloading, increases in saltconcentrations and wetland managersin the Basin. Wetland tracemetals, and decreasesin water clarity. managementtherefore has become a commonly Diversion of freshwater tributaries can lead to acceptedpractice (Kadlec & Smith 1989). In order to dramaticdegradation of lacustrinewetlands, as seen mimicthe natural hydrologic cycle of springrunoff in LosAngeles' diversion of tributarywaters from and progressivedrying throughthe summer, Owens and Mono Lakes. These diversions over 50 managersmust have adjudicated water rights. Even yearsled to a declinefrom nearly 1,000,000 then,access is not guaranteedas water rightsoften exceedavailability. waterfowlto about10,000. Ground water aquifers are impactedby increasedurban growth in LasVegas The criticalneed for wetland managementin the and Reno-Sparks.Railroad Valley's marshes are Basin received new interest and focus with creation currentlyfed by numerousfree-flowing springs. Las of the Intermountain West JointVenture (IMJV). The Vegashas targeted Railroad Valley's large aquifer as IMJV targeted161,000 ha for primary protectionand a potentialurban source (M. Biddlecomb,Ducks restoration(Ratti & Kadlec1992). Restorationgoals Unlimited,Inc., pers.comm.). Loweringthe aquifer rangefrom creationof impoundmentsand water of thisvalley couldresult in the dryingof the area's controlprojects to reestablishingnatural hydrologic marshes,including those inhabited by the connections between basins and creeks. endangeredRailroad Valley Springfish (Crenichthys Alreadyefforts to restoreand createwetlands at river nevadae). and springinlets have met with somesuccess, The Basinhas long beenexploited for its mineral includinga portionof the400 ha RailroadValley richesto the detrimentof groundwater aquifers. Wetlands,Nevada, the 1,560ha River'sEnd project Massivedewatering efforts associated with modern at Lake Abert, Oregon, and the 3,160ha Warner gold mining operationscontinue to degradeground LakesProject, Oregon. Theseprojects are being water sources.In addition,milling and leaching accomplishedthrough multi-partner efforts operationsgenerate toxic liquid wastes. Thesewaste involvingstate, federal, and non-profit productsare piped to evaporationponds that attract organizations.Because of this success,wildlife migratingwaterbirds. Severalmines have been fined agenciesand non-profitorganizations, like Ducks for the adverseimpact of thesetoxic evaporation Unlimited,Inc. (DU), havedeveloped policies to pondson migratorybirds. clusterrefuges around viable river and streaminlets to terminal basins, not within basin bottoms alone. The introductionof thecommon carp (Cyprinus carpio)has presented unique problems for Basin Thelargest, most complex, and perhapsthe most marshes.Carp occurin mostmajor wetlands in the importantrestoration project in the Basininvolves west, can tolerateextreme water temperaturesand theLahontan Valley, Nevada. Thismassive area low oxygenlevels, and are responsiblefor numerous includesStillwater National Wildlife Refuge,Carson problemsin wetlands.Their bottomforaging Lake,which is managedby theNevada Division of activitiesdislodge aquatic plant beds,impact Wildlife, and variousother federal, state, and private invertebratemasses, and increaseturbidity, thus lands. For a historyof thiscritical area, a summary reducingphotosynthetic activity by submerged of its wildlife, and further discussion of efforts to plants(Robel 1961; Ivey 1990). In somewestern purchasewater for it, seeNeel & Henry,this volume. marshes,carp populationsaccount for 90% of the fish biomass(pers. comm. J. Morgan,Portand Metro Department). Wetland construction: Tamarisk(Tamarix spp.), a treenative to Eurasiaand levees,dikes, and spillways Africa,was brought to thesouthwestern U.S. for windbreaksand shade(Kearny & Peebles1959). Beforecreating impoundments, managers should This fastgrowing tree can survive in wetlandand considersoils, hydrology, topography of the alkali habitatsand hasspread throughout warmer restoration site, water circulation, water control, and areas in the western United States. Tamarisk can pondbottom elevations (Charney et al. 1995).

75 International Wader Stu&es 9:71-79

Certaindike and leveedesigns can provide excellent The soils must be characterized to determine if, when habitatfor shorebirds.Levees should have gentle innundated,they will sealsince soil types vary side-slopes.In most Basinmarshes, levees needed to enormouslyin theirwater holdingcapacity (Figure impoundwater for shorebirdsneed not exceed90 cm 4). Auger boringtests can determinethe extentof in height. The requiredheight would be predicated the confiningclay layer and characterizesoil on the area'stopography. Side slopes of levees horizons.Where clay is to be usedfor levee shouldbe designedfor a 5:1 to 10:1slope. A 90 cm construction or is to be excavated, thickness of the high levee,with a 3.6 m top width, thenwould have clay layermust be determined.A claycontent of a width of 13 m (5 m+3 m+5 m) for 5:1slope and 21 10%is essentialfor leveeconstruction while clay m (9 m+3 m+9 m) for a 10:1slope. Gradualslopes contentgreater than 30% is consideredideal. If sand providesuitable foraging habitat in a linearband formsa lensunderlying the confining clay layer, it is aroundthe impoundment. imperativethat the claylayer not be breached.If it is, a drainis createdand thewater holding capacity The areasof the impoundmentthat can provide the of the impoundmentis compromised.The adequacy dirt necessaryfor leveeconstruction (borrow sites) of the site's soils for levee construction should be shouldbe selectedwith care. Two strategiescan be testedby an engineerprior to construction. employed(Figure 3). A borrowsite on the high elevationsof thepond shouldbe identified. Borrowingfrom the high elevationswill lower that areaaccordingly. It is importantthat finished elevationsproduce desired water depthswhen flooded. Anotherstrategy is to borrowalong the lengthof the levee. Here a set-backof 15 to 30 m allowsmarsh vegetation to growbetween levee and borrow channel. The borrow should have shallow slopes(15:1) and shouldnot exceedthe desired depthsfor shorebirduse. Borrowchannels should alsobe wide enoughto allow accessof conventional farm equipmentfor diskingor otherphysical manipulations.

• • • %Levee/ Percent silt

Figure4. U.S. Departmentof Agriculturesoil trianglechart.

Thoughlack of water is the mostimportant problem facingBasin wetlands, periodic flooding wreaks havocwith managementefforts. In the mid 1980s, floodsobliterated many ponds, levees, and control structures.The key to survivalof thesefacilities is spillwaydesign that can relieve flood water pressure. Spillwaysvary from low, earthenareas on dikesto geoweb-lineddikes and concretestructures. Spillwaysshould be designedby engineersbased on hydrologicdata of inflowingstreams. Spillways in the Basingenerally are sized to accomodatea 50 to 70 year floodevent, but somelarger ones accomodate a 100 year event.

Wetland construction: vegetation removal

One of theprimary goals of managedwetlands is to createa setof conditionsto managewater levelsand controlmarsh vegetation. In systemswhere the groundremains saturated, levees may not be a cost effective alternative for restoration and control. Numeroustechniques have been employed in Basin refuges(Kadlec & Smith1989, Fredrickson & Dugger 1993). Blastingto provideopenings should not be Figure 3. Dirt borrow strategiesfor diked wetland employedin playasand marshes,because blasting construction. Boxed numbers are relative units of cancompromise the claylayer and drain the site. elevation. Also, usable habitat is reduced due to the cone-

76 Engihs& Reid:Wetland restoration challenges shapedprofile of blastholes (Fredrickson & Dugger with legumesprovides excellent upland cover. Great 1993). Removalof vegetationusing herbicides Basinwild rye (Elymuscinereus) has shown great followedby burning canbe effective.The successof successin meadowmanagement areas. herbicideapplications varies with plant species,time Braided meadows have been restored in the Basin, and methodsof application,and concentrations.The manufacturer of the selected herbicide should be createdby establishinga networkof smallspillways contacted to determine these variables. within a drainageway. Two areaswhere braided meadows have been restored are Wanakut Wildlife Excavationof overgrownvegetation to re-opena Area, Oregon(managed by the Umatilla Indian marshcan be expensive,but is logisticallypossible, Reservation) and at DeChambeau Ponds, Mono even in wet conditions.As with blasting,great care Lake,California. At Wanakut,area managers in not breachingthe claylayer mustbe taken. breachedseveral irrigation channels to spreadwater Equipmentoperating on speciallydesigned mats to acrossa meadow.The water soughtits own allow for accessinto marshescan be usedto reopen channels,creating swells and floodedgrassy habitat. channels,ponds, and createa diverseshoreline. CommonSnipe and Wilson'sPhalaropes nest as well Excavationof vegetationmats and rootballs may be asCinnamon Teal, Mallard, Sora,and Long-billed all that canbe accomplishedwithout compromising Curlew. the clay layer. If the marshis too deepfor mats, severalfloating machines can be employed. Aquamogsand cookie-cutterscan be usedwhen Wetland construction:nesting islands water depthsare 30 cm. Thesemachines have variableattachments to allow for the mulchingof Also of importancefor shorebirdshas been the root masses,vegetative materials, and woody plants. managementof nestingislands within units. Again All the abovetechniques can maintain desired severalconfigurations can be utilized, but thosemost interspersionfor yearsafter application, the resultof successfulfor shorebirdsare shallowlysloped and shortenedgrowing seasons in the Basin(Kadlec & low. The shoreline, if terraced to create shallows, can Smith 1989;Fredrickson & Dugger 1993). provideexcellent foraging habitat for adult and young shorebirds.Past efforts to build islandshave involvedpushing material into a mound and Wetland construction:upland habitat creatinga deeper"trench" around the island. A moreeffective technique would be to build the island The creationand managementof moist-meadow utilizing strippingsor excesssoil from borrow areas. habitatand othergrassy wetlands to provideupland If this cannotbe accomplished,then selecta borrow nestinghabitat for shorebirdsremains a challengein areaoff oneside of theisland allowing a 15 m the Basin. Severaltechniques have been employed to minimum buffer between the island and the borrow providepermanent water for waterfowland other area. The result is a shallower base habitat near the deepwater nestingspecies, but few have attempted islandand a slopingshoreline (Figure 5). shallowhabitat or moist-meadowmanagement. Severalshorebirds prefer to forageand nestin moist meadowor shallowemergent marsh. Moist meadowscan be managedto provide for flooded springconditions benefiting shorebirds, cranes, rails, and BlackTerns. The completionof the waterbird breedingseason can then allow managersto dry and mow or grazethe meadowsto providefor upland foragingspecies such as geese,cranes, and curlews. Key to any moist-meadowrestoration is the flexibility to usewater when needed. Wellsare often employed,but streamdiversions can be utilized for at leastportions of the summer.A similar infrastructureused by ranchersto floodpastures can Plain view of island be employedon refuges.Parallel checks can send water down the meadow, and small levees can impound the water to accommodatedepths to 15 cm. Most areasuse a delivery ditch with 15 - 30 cm wide culvertswith slidegates to allow for water control. Max. 70 cm above mean water surface In higherelevations, Juncus, Eleocharis, and graminae •-- } Watersurface speciesdominate moist-meadow habitats as at Modoc NWR, Californiaand Ruby Lake NWR, Nevada. Lower elevationareas with poorersoils can be dominatedby saltgrass (Distichlis) and sedges Islandlo//•• Borrowtodrain (Carexand Scirpus)as in RailroadValley, Nevada and Honey Lake StateWildlife Area, California. Areas with bettersoils can provide excellent upland grass Section view of island and borrow and legumemixtures. Ogden Bay State Wildlife Area, Utah hasexperimented with variousmixtures Figure5. Typicalnest island profile showing preferred dirt and hasfound native bunchgrass and western borrow location. Boxed numbers are relative units of wheatgrass(Agropyron smithii) mixtures inter-seeded elevation.

77 International Wader Stu&es 9:71-79

Managingislands for shorebirdsrequires periodic However, aswith carp, the re-invasionroute must be vegetationmanipulation. Usually a pond hasa dealt with. Here is where tamarisk control has met complexof islands,including densely vegetated its biggestchallenge, and no solutionshave been islandsfor speciessuch as waterfowl, and open offered to date. islands,where vegetationis removedfor nesting A similarthreat, purple loosestrife(Lythrum salicaria), Killdeer,stilts, and avocets.Management plans can is invadingthe Basinfrom the north. Thisplant is be developedthat allow for fall burningof island alreadya problemin the ColumbiaBasin, and efforts vegetation.Burnt islands will green-upin spring, by the stateand federalgovernment to containit providingshort grassy habitat for shorebirdnesting. have had limited success. Control of loosestrife has The only Basinwildlife areato employa shorebird centeredaround eradication of the plant through nestingisland management program has been the herbicideapplications and physicalmanipulation JayDow, Sr.Wetlands, at HoneyLake, California. coupledwith water control.The minuteand The University of Nevada, Renohas continuedto profuselyproduced seeds of purple loosestrifemake rotate island coverfrom open to densevegetation re-invasioncontrol a real challengebecause seeds and shorebirdnesting has been maintained for five stickto the bodiesof migratorybirds and arewidely years. Even GreaterSandhill Cranes have nestedon these islands. dispersed.In the mid 1990sbiological control showedsome promise in the war againstpurple Most nestingislands are surroundedby permanent loosestrife(D. Kraege,Washington Department of water which limits land predators,but predationby Fishand Wildlife, pers.comm.). gulls, harriers,owls, and heronscan limit reproductivesuccess. To combatthis, islandsshould not be too small to behaviorallylimit predator Diseases avoidancedisplays used by shorebirds.Quantitative data to show when island sizebecomes limiting to The incidenceof disease,especially avian cholera successfulshorebird reproduction are not available. and botulismType C, in the Basinhas been well Numerousshapes of nestingislands have been documentedfor waterfowl (Kadlec& Smith 1989). employed,but thereare no shapesthat work best. At one Great Basin site, the Great Salt Lake, the 1994 The creationof nestingislands should have three cholera outbreak killed tens of thousandsof , basicparameters driving their final configuration: includingshorebirds. The controlof both diseases optimal shoreline,distance to otherislands and lies with adequatewater controland removalof shore,and slope. For thesereasons, several wildlife carcasses.Adequate water controland flow are areasuse a sinuousor hourglassshape for islands, needed to reduce the threat of disease outbreaks. limit their height from 30 cm to 60 cm above When designingimpoundments three conditions maximum water levels,and establisha slopewith a must be met in order to minimize stagnantwater and minimum 5:1 ratio (Figure5). associateddisease outbreaks: 1) adequatewater must be availableto allow for replenishmentthrough the long,hot summerand falls,2) adequatedrains and Alien organisms controlstructure should be provided to maximize circulation,and 3) inflow areasshould not be too The controlof alien animalsand plantshas become a closeto outflow structures,thus minimizing "dead paramount issuefor wetland managers. Managersat areas"in a pond. Malheur NWR and LahontonValley are concerned aboutcarp. Waterfowlproduction at Malheur NWR prior to carpinvasion peaked at 147,000birds in Conclusion 1948. Sincethen, annualproduction of duckshas declinedto 30,000;the declinewas attributedto carp Wetlandsof the Basinare a biologicallyvaluable, but increases(Ivey 1990).Nationally, losses of aquatic often overlooked, continental resource. Continued vegetationbeds to carp have resultedin declining protectionand ongoingefforts to restoresome of waterbirdproduction rivaling bird lossdue to thesewetlands will be a fluid process.As scientists diseasessuch as botulism (Ratti & Kadlec 1992). and managersincrease their understandingof Basin Carp canbe controlledusing rotenone poisoning, marshes,new techniquesfor restorationcan be draw-downs(if possible),and eliminatingre- developed.It is criticalthat managersoutline project invasionpathways, e.g., via fish screens.Rotenone goalsand coordinateefforts with otherBasin providesshort-term benefits, but its usemust be managers.The IMJV providesa dynamicnetwork accompaniedby eliminatingre-invasion routes. for managersacross the Basin,particularly when Rotenone treatments at Malheur NWR resulted in a dealingwith shorebirds.Some practices widely used temporaryincrease of sagopond weed (Potamogeton for waterfowl canbe employedfor shorebirds.These pectinatus)from 830 ha to 4,930ha, with an increase includemoist-meadow management, nesting island of diving duck use daysfrom 807,000to 3,000,000 management,and modifiedimpoundment (Ivey 1990). development.The projectgoals should be met by examiningthe variablescritical to a successful Tamariskposes a great threat to shallowwetland restorationproject including: historic and current managementin the Basin. Variablewater levels,a hydrology(ground and surface),soils, and water commonoccurrence in the Basin,provide ideal managementcapabilities. conditionsfor tamarisk.The ability to maintain water levels is essential for successful control.

78 Engilis& Reid:Wetland restoration challenges

Acknowledgments waterquality, bottom sediment, and biota. U.S. Geological SurveyRep. No. 92-4024-C. Ivey, G. 1990.The need for carp eradicationon Malheur This manuscriptwas madepossible through the NWR. IssuePaper, Feb. 7, 1990,Malheur Natbnal Wildlife input of severalspecialists. Engineering Refuge.Princeton, Oregon. considerationsand techniqueswere providedby Jehl,Jr., J. R. 1994. Changesin salineand alkaline lake DucksUnlimited, Inc. WetlandEngineers R. Charney avifaunasin westernNorth Americain the past 150 and J. Well. Figureswere draftedby P.Goebel, years.Stud. Avian Biol. 15: 258-272. Ducks Unlimited, Inc., J. M. Reed, N. Warnock, and Kadlec, J. A., & Smith, L. M. 1989. The Great Basin marshes. In: L. M. Smith, R. L. Pederson, and R. M. Kaminski S. Warnock. We thank M. Biddlecomb, R. Drewien, L. (eds.),Habitat management for migratingand wintering Oring, N. Warnock,and J.M. Reedfor providing waterfowlin NorthAmerica, pp. 451-474.Texas Tech. helpful comments.Special thanks go to all of the UniversityPress, Lubbock. refugemanagers, past and present,of stateand Keamey,T. H., & Peebles,R. H. 1959.Arizona flora. federal lands in the Basin. Their efforts have made Universityof CaliforniaPress, Berkeley. this synthesispossible. Page,W. P.,& Gill, R. E., Jr.1994. Shorebirds in western North America: Late 1800's to late 1900's. Stud. Avian Biol. 15: 147-160. References Ratti,J. T., & Kadlec,J. A. 1992.Concept plan for the preservationofwetland habitat of theIntermountain West. U.S. Fishand Wildlife Service,Portland, Oregon. Alberico,J. A. 1993. Droughtand predationcause avocet Robel,R. J. 1961.The effectsof carppopulations on the and stilt breedingfailure in Nevada. WesternBirds 24: productionof waterfowlfood plantson a western 43-51. waterfowl marsh. Trans. North Amer. Widl. and Nat. AmericanOrnithologists' Union. 1983.Check-list of North Resour.Conf. 26: 147-159. Americanbirds, 6th edition. American Ornithologists' Ryser,Jr., E A. 1985.Birds of theGreat Basin: A naturalhistory. Union. Washington,D.C. Universityof Nevada Press,Reno. Anglin, A., & ShellhornG. 1992. GreatBasin wetlands, a U.S. Departmentof Commerce.1983. Climatic atlas of the conceptpaper. Unpub. U.S. Fishand Wildlife Service UnitedStates. Environ. Data Serv., U.S. Dept.of document, Fallon, Nevada. Commerce,Washington, D.C. Charney,R. L, Well, J.R., Engilis,A., Jr.,Reid, F. A., & U.S. Fishand Wildlife Service.1989. Concept plan for Goebel,P. 1995.A guideto wetlandrestoration on private waterfowlhabitat protection Klamath Basin, Oregon and land.Valley habitats: A tech.guide. Series no. 4. Ducks California.Portland, Oregon. Unlimited, Inc., Sacramento, California. U.S. Fish and Wildlife Service. 1994. Stillwater Marsh Dahl, T. E. 1990. Wetland lossesin the United States,1780s to NationalWildlife Refuge management plan: Provisional 1980s. U.S. Departmentof the Interior, Fish and draft. Portland,Oregon. Wildlife Service,Washington, D.C. Wilson,J. L. 1986.Ruby Lake National Wildlife Refuge, Ruby Ducks Unlimited, Inc. 1994. Ducks Unlimited continental Valley,Nevada: Management plan. U.S. Fishand Wildlife conservationplan: An analysisof North American waterfowl Service,Portland, Oregon. populationsand habitats, Part II, pp. 135-314.Ducks Unlimited, Inc., Memphis,Tennessee. Duebbert,H. F. 1969.The ecology of Malheur Lake and managementimplications. Bureau of SportsFisheries and Wildlife,U.S. Fishand Wildlife Service. Washington, D.C. Durrenberger,R. W., &. Johnson,R. B. 1976.California: Patternson theland, 5th ed. Mayfield Publ.Co., Palo Alto, California. Fredrickson,L. H., &. Dugger,B. D. 1993.Management of wetlandsat highaltitudes in theSouthwest. U. S. Departmentof Agriculture,Forest Service, Southwest Region,Washington, D.C. Fredrickson,L. H., & Reid,F. A. 1990.Impacts of hydrologic alterationon managementof freshwaterwetlands. In: Staticwetland management symposium, pp. 71-90.51st MidwestFish and Wildlife Conf., West Lafayette, Indiana. Grayson,D. K. 1993.The desert's past: A naturalprehistory of theGreat Basin. Smithsonian Inst. Press, Washington, D.C. Hayward,C. L., Cottam,C., Woodbury,A.M., & Frost,H. H. 1976. Birds of Utah. Great Basin Naturalist Memoirs. No. 1. Heitmeyer,M. E. 1991.Wetlands and cattlegrazing: Impacts and managementconsiderations for waterfowl.In: F. M. Byers(ed.), Cattle on the land: A conference.Texas A&M UniversityPress, College Station. Helmers,D. L. 1992.Shorebird management manual. Western HemisphereShorebird Reserve Network, Manomet, Massachusetts. Hoffman,R. J. 1994.Detailed study of irrigation drainage in andnear wildlife management areas, West-Central Nevada, 1987-90.Part C. Summaryof irrigation-drainageeffects on

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