Seattle’s Aquatic Environments: Marine Nearshore

Marine Nearshore The following write-up relies heavily on the Review Draft of the State of the Nearshore Ecosys- tem: Eastern Shore of Central Puget Sound, Including Vashon and Maury Islands (WRIAs 8 and 9). January 2001 (Review Draft) for the WRIA 8 and 9 Nearshore Technical Committee.

Overview The city of Seattle’s marine nearshore area extends cumulative impacts of urban development have from North 145th Street south to Brace Point in resulted in major changes to the shoreline environ- West Seattle and includes approximately 30 miles ment and the marine nearshore ecosystem. Rela- of Puget Sound shoreline. The nearshore environ- tively little is known about the direct effects of ment in the city of Seattle includes areas within urban development and other human impacts on both WRIA 8 and WRIA 9. Approximately 8 the migration, growth, survival, and habitat of miles of shoreline is within Elliott Bay and 2.5 Chinook salmon in the marine nearshore areas of miles of shoreline is within Shilshole Bay. Seattle. However, we do know that bulkheading, bank armoring, and other human activities within The nearshore environment in Puget Sound shoreline areas have affected many physical possesses an extremely productive and dynamic processes including sediment production and ecosystem. Tides, currents, wave action, and transport, and that these processes are important intermixing of salt with freshwater create a com- for forming and maintaining habitat for juvenile plex physical environment situated at the juncture Chinook salmon in the marine nearshore and between land and water. The marine nearshore estuary areas. environment encompasses the area from upland bluffs, banks, and beaches, and the lower limit of The marine nearshore environment within the city the photic (light penetration) zone, which varies of Seattle can be divided into four areas: Elliott with season and climatic conditions. Some define Bay, Shilshole Bay, Duwamish Estuary, and other the lower limit of the photic zone at approximately nearshore areas. These areas are discussed below 100 feet below the Mean Lower Low Water except for the Duwamish Estuary, which is (MLLW) line. The nearshore area includes a wide discussed in a separate section of this report. variety of upland, marine, and estuary habitats including marine riparian areas, backshore areas, Elliott Bay beaches, tidal marshes, tidal flats, eelgrass mead- Historically, Elliott Bay consisted of extensive ows, kelp forests, and exposed habitats. Terrestrial intertidal mud and sand flats and vegetated wet- habitats along the shoreline such as bluffs, sand lands bordered by steep banks (Blomberg, 1995). spits, and coastal wetlands are also included within The development of the existing downtown the nearshore environment, as well as the tidally- influenced region found within the lower sections of mainstem rivers and coastal streams.

Historical Modifications

Physical Changes Human alteration to the nearshore environment has been occurring in Seattle since at least the late 1800’s. These activities included extensive filling within Elliott Bay and other areas to increase the city’s land base, bank hardening along a significant portion of the shoreline areas for a railroad right- of-way and for property protection, and construc- tion of commercial piers and marinas. The combi- nation of these historic habitat losses and the It is unclear whether shallow water habitat under overwater structures is used by Chinook. 81 Seattle’s Aquatic Environments: Marine Nearshore end.i Afterthe reroutingoftheCedarRiver and brackish waterandasaltwater marshatitseastern draining theLakeUnionwatershed. Itfeatured Salmon Baywastheestuary ofasmallcreek to thetipofMagnoliaatWest Point.Historically, running northtosouthfrom GoldenGardensPark stretch ofthePugetSoundnearshoreshoreline its westernenditconnectstoShilsholeBay,a to abouttherailroadbridgewestofLocks.At Locks, andextendseasttowestfromLakeUnion includes theFremontCutandHiramChittenden drainage (WRIA8)toPugetSound.SalmonBay Canal systemandconnecttheLakeWashington westernmost portionoftheLakeWashingtonShip Salmon andShilsholeBaysarelocatedatthe Shilshole Bay broad sandflatsnearWestPoint. tinue tosupportthebeachesnorthand Magnolia neighborhoodremainactiveandcon- city centerandfeederbluffsalongthecity’s 2001). Lessarmoringhasoccurrednorthofthe including juvenileChinooksalmon(KCDNR, important toavarietyofmarineorganisms, support productiveeelgrasspatchesthatare areas betweenAlkiPointandDuwamishHead subtidal sandflatsandotherremnantsandy from DuwamishHeadtoAlkiPoint.Theshallow spits toanarea areas providedbybeachesandsand armoring alongElliottBayhasreducedthehabitat tion andmaintenanceofnearshorehabitats.Bank sediment inputsthatareimportanttotheforma- reduced shorelineandblufferosion,reducing Armoring oftheshorelinesElliottBayhas located atthesouthernextentofElliottBay. Bay. ThemouthoftheDuwamish/GreenRiveris city ofSeattleandKingCountydischargetoElliott combined seweroutfalls(CSO)operatedbythe deeper (Weitkamp with waterdepthsdroppingrapidlyto80feetand shoreline areasofElliotBayhavebeenaltered, Duwamish RivertoHead.Mostofthe Elliott Bay,andarefoundfromthemouthof natural characteristicsareverylimitedwithin percent ofthebayshore.Shorelineareashaving nant shorelinemodification,occupyingover65 Elliott Bay,overwaterstructuresarethepredomi- seawalls, bulkheads,andoverwaterstructures.In shoreline alongElliottBayischaracterizedby shoreline (Weitkamp extensive filling,dredging,andgradingalongthe business andindustrialdistrictshasresultedin et al et al ., 2000).Inaddition,several ., 2000).Currently,the 82 inputs, transport, anddeposition,altered substrate armoring andresultingreductions insediment habitats withinthisregion are affectedbybank et al affected byextensivefilling ordredging(Weitkamp nearshore environmenthas notbeendirectly Shilshole Bay,thelowerintertidalregionof habitats. UnlikethesituationinElliottBayand distribution andavailabilityofupperintertidal these nearshoreareashassubstantiallyreducedthe been placed.Theextensivebankarmoringalong embankment uponwhichtherailroadtrackshave is protectedfromwaveactionbyalargeriprap directly adjacenttotheshoreline.Therailroadbed a railroadright-of-waywhichhasbeenconstructed areas northofGoldenGardensPark,asaresult armoring isnearlycontinuousalongthenearshore properties, roads,andrailroadright-of-ways.Bank construction ofbulkheadstoprotectresidential majority ofthisarmoringhasoccurredfromthe WRIA 9havebeenarmored(KCDNR,2001).The shoreline inWRIA8and75percentof region ofthecity.Approximately87percent and maintenanceofnearshorehabitatwithinthis armoring isamajorfactoraffectingtheformation and industrialfacilities,cityparks.Bank for afewwater-dependentmunicipal,commercial, affected primarilybyresidentiallanduse,except The shorelineareassouthofElliottBayare Other Shoreline Areas the sandbeachareasofGoldenGardensPark. the cliffsandbluffsinDiscoveryPark,within areas withinShilsholeBayarefoundadjacentto the CityofEverett.Themostnaturalshoreline railroad thatextendsnorthfromSalmonBayto marina andwaterfrontparks,bulkheads,the the constructionofroads,parkingareafor terrestrial uplanddevelopmentislargelylimitedby and intertidalhabitats.Connectionwithbluffs filling thathasresultedinthelossofbothsubtidal a largebreakwaterjetty,dredging,andshoreline north ofShilsholeBayinvolvedtheconstruction construction oftheShilsholeBaymarinaon and qualityofshallowintertidalhabitat.The bank armoring,whichhasreducedthequantity both bays.Thisareahasexperiencedsubstantial downstream oftheHiramM.ChittendenLocksin Residential developmentistheprimarylanduse larger freshwatersystem. Shilshole Bay,becametheestuaryforamuch western endofSalmonBay,togetherwith construction oftheShipCanalandLocks, ., 2000).Thelowerintertidal andsubtidal Seattle’s Aquatic Environments: Marine Nearshore composition, and loss of riparian vegetation. Most Chinook spend from two to four years feeding in Puget Sound and the Pacific Ocean Exotic Plants and Animals before reaching sexual maturity (Myers et al. 1998). Little information is known regarding behavioral The Puget Sound Expedition Rapid Assessment differences between the two populations in relation survey for non-native marine organisms was to their use of nearshore habitats. However, it is conducted September 8 through 16, 1998. This assumed that nearshore habitats play a more study found 39 non-native species in the samples important role to resident blackmouth, which are collected in Puget Sound. Eleven non-native more likely to use the nearshore environments of species found in the survey were new observations the Puget Sound than ocean rearing adult Chi- for Puget Sound and five species were thought to nook. occur in the Sound, but had not been previously documented. Currently, it is unknown what, if Juveniles any, impacts populations of these non-native species have on juvenile and adult Chinook salmon Puget Sound Chinook, including those from the in the marine nearshore and estuary areas of the Lake Washington and Green River drainages are city. “ocean type” Chinook, meaning that they spend less time rearing in fresh water and outmigrate to Chinook Utilization of the Marine saltwater as smaller fry (Meyers et al. 1998). Based upon observations at the Hiram M. Chittenden Nearshore Locks, juvenile Chinook migrate from Lake Nearshore marine and estuary environments Washington to Puget Sound from mid-May into provide important habitats to several life stages of July (Goetz et al. 1998), with some Chinook smolts Chinook salmon, including: migrating through the locks at least into July (K. Fresh, pers. comm., cited in Weitkamp 2000). o Subadult and adult resident blackmouth, which Similar migration timing is thought to occur for is a population of Puget Sound Chinook that Green River Chinook, although monitoring is does not undergo an ocean migration, but more difficult as there is no single point where instead matures within Puget Sound; outmigration can be easily observed. o Adult Chinook returning from the ocean that Recent data suggest that juvenile Chinook are migrate through nearshore areas prior to commonly found using nearshore habitats of King entering freshwater to spawn (KCDNR 2001); County from late January through September, and and it is probable that Chinook juveniles utilize o Juveniles that have recently outmigrated from nearshore habitats, to some extent, year-round freshwater habitats. (KCDNR 2001). The period of use within estuary and marine nearshore areas of the city may be Moreover, the nearshore environment provides highly variable among individual juvenile fish. essential spawning and foraging areas for baitfish Shepard (1981) found that some individual Chi- including herring, surf smelt, sand lance, and nook may utilize estuarine and nearshore habitats shiner perch, upon which subadult and adult for as few as four days, while other authors have Chinook feed (Fresh et al. 1998). documented that juvenile Chinook use estuary habitats for up to 189 days (Wallace and Collins, Subadults and Adults 1997; Levy and Northcote, 1982). There is little Adult Chinook salmon return to spawn in their “hard” information on the residency time of natal streams from mid-May through October juvenile Chinook salmon in nearshore areas (Myers et al. 1998). Chinook salmon in Puget (KCDNR 2001). Sound area generally form two populations, a resident population commonly referred to as Habitat Requirements “blackmouth” and an ocean rearing population. Blackmouth reside in Puget Sound for their entire Juveniles life cycle. Ocean rearing Chinook migrate to the Many factors, such as the distribution and abun- north Pacific where they mingle with other stocks dance of predators, food availability, tides, river before returning to Puget Sound streams to spawn. flows, and genetics may affect how and when 83 Seattle’s Aquatic Environments: Marine Nearshore nearshore habitats toavoidpredatorsincluding Predator Avoidance. migration tofreshwaterspawning areas. freshwater environmentsduring theirupstream mouths asatransitionzone betweensaltand the nearshoreenvironmentinestuariesandriver Both blackmouthandocean-rearingChinookuse nearshore areasaswellindeep-waterhabitats. however, residentblackmouthmayalsoforagein thought toresideprimarilyinpelagichabitats; forage innearshoreareas.AdultChinookare Subadult Chinookandadultblackmouthmay adult andChinookisnotwellunderstood. Direct useofnearshorehabitatsbymaturingsub- University ofWashington,pers.comm.). shallow shorelinehabitats(DavidBeauchamp, using beachseineswhicharerestrictedinuseto well, becausemostsamplinghasbeenconducted Chinook useindeepernearshorehabitatsvery sampling effortstodatehavenotexaminedjuvenile channels nearestuaries(KCDNR2001).However, meadows, tidalmarshes,andshallowsubtidal nearshore areasincludingintertidalflats,eelgrass juvenile Chinookaremostabundantinshallow The resultsofbeachseinesamplingindicatethat Pearce the PacificOcean)(LevyandNorthcote,1982; environments (i.e.,deeperPugetSoundwatersor and conditionbeforemovingintomorepelagic nearshore systemstoincreasetheirbodyweight are moredependentonforageintheestuariesand outmigrate asyoungerandsmallerjuveniles,they Duwamish River).BecausePugetSoundChinook saltwater (especiallymouthsofcreeksand the physiologicaltransitionfromfreshwaterto over, someoftheseareasareusedbyjuvenilesfor the centralPugetSound(KCDNR2001).More- salmon formigration,feeding,andrearingwithin particularly importantforjuvenileChinook Marine nearshoreareasandestuariesmaybe ated withshorelineareas(Levings juvenile Chinookarefoundtobestronglyassoci- other regionsofthePacificnorthwest,where 2001). Thisisconsistentwithobservationsin shallow habitatslocatedclosetoshore(KCDNR Puget Soundtendtobecloselyassociatedwith marine nearshoreandestuaryareasofcentral this report),juvenileChinooksalmoninthe Lake Washington(seesummary, Seattle. Likethehabitatusepatternsobservedin marine nearshoreandestuaryareasofthecity juvenile salmonidsuseandmigratethroughthe et al ., 1982). JuvenileChinookusethe et al . 1983). 84 materials infish, shellfish,andmammals (Williams (Lynn, 1998),andbioaccumulation oftoxic tion, algalbloomscausedby nutrientenrichment ering ofmarineplantsthrough excesssedimenta- graded waterandsediment qualityincludesmoth- sediments (Lynn,1998).Adverse effectsofde- contribute contaminantstonearshorewatersand practices, andclearinggradingpracticesall including municipalsewageoutfalls,agricultural basin, stormwaterrunoff,pointsourcedischarges Water Quality. o o o Puget Sound,including: food webconnectionsforChinooksalmonin Washington hasidentifiedimportanthabitatsand nearshore foodwebanalysisbytheUniversityof habitat typeandthesizeoffish.Current vary dependingontheestuarineornearshore pelagic organisms(Fresh prey onanarrayofbenthic,epibenthic,and 1982). Whileinthenearshore,juvenilesalmonids feeders withdietsthatvaryconsiderably(Healy, adult Chinook.Youngsalmonareopportunistic species utilizedbybothjuvenile,sub-adult,and supports populationsofseveralimportantprey Food Availability. Weitkamp 1882, Rate,1985,WilliamsandWeitkamp,1991in Farley, 1975,WeitkampandKatz,1976, increased predationonChinook(Weitkampand able astowhetheroverwaterstructuresresultin piers inmarinenearshoreareasanditisquestion- avian predators.Predatorsappeartoberareunder larger substrateproviderefugefromaquaticand water structuressuchaslargewoodydebris,and vegetation suchaseelgrassbedsandkelpforests,in- and Caspianterns(Weitkamp salmonids, mergansers,grebes,pigeonguillemots, in thenearshoreincludestaghornsculpin,other both otherfishandwaterfowl.Primarypredators copepods (Cordell and crablarvae,planktonicamphipods, planktonic grazerssuchaseuphasiids,shrimp, eelgrass bedsandkeptforeststhatsupport benthic macroinvertebratesfeed. concentrations oforganicdetritusuponwhich crustaceans. Theseareasgenerallypossesshigh produce amphipodsandotherepibenthic intertidal andshallowsubtidalareasthat (Brennan andCulverwell,inprep.). the sourceofterrestrialinsectsindiets nearshore vegetatedterrestrialhabitatsthatare et al ., 2000). WithinthegreaterPugetSound Thenearshoreenvironment et al et al ., unpublished). ., 1981).Preyspecies et al ., 2000).Aquatic Seattle’s Aquatic Environments: Marine Nearshore

result in reduced survival of these species’ eggs and larvae (Pentilla, 2000).

Landscape and Habitat Forming Processes The marine nearshore region within central Puget Sound includes several types of distinct habitat areas, including eelgrass meadows, kelp forests, tidal flats, tidal marshes, river and stream mouths and deltas, sand spits, beaches and backshores, and marine riparian zones (KCDNR 2001). These areas are defined in relation to abiotic and biotic factors including vertical position relative to the tide, slope, substrate composition, vegetative Eelgrass beds in Puget Sound. Photo courtesy of King County. composition, and salinity. The formation, mainte- nance, and spatial distribution of these diverse et al., In Prep.). habitat areas are determined by several key physi- cal processes. The most important of these physi- Subadults/Adults cal processes are those related to sediment inputs, transport, deposition, and redistribution within the Food Availability. Nearshore areas also provide marine nearshore and estuary zones. habitat for fish species that serve as prey for subadult and adult Chinook. Surf smelt, longfin As discussed above, land use patterns and habitat smelt, Pacific sand lance, eulachon, and Pacific modifications within the nearshore environment in herring are major forage fish for subadult Chi- the city of Seattle have the potential to affect nook, blackmouth, and ocean-rearing adult Chi- survival, growth, and condition of juvenile, nook while in Puget Sound (Fresh et al. 1998). subadult, and adult Puget Sound Chinook. Factors While all five species commonly occur in that have impacted the functions of the marine nearshore areas as adults, eulachon and longfin nearshore environment include the loss of habitat smelt do not spawn in marine nearshore habitats within the migratory corridor, degradation of and no spawning areas for Pacific herring are water and sediment quality, alteration of physical known to occur within Seattle shoreline. It is processes including bank erosion and alongshore unclear what effect nearshore habitat alterations sediment transport, loss of riparian functions, and have had on eulachon, herring, and longfin smelt. introduction of non-native species. Habitat impacts on forage fish (baitfish) within Seattle may have a greater effect on sand lance and surf smelt populations than other forage fish species. Sand lance commonly spawn within the Seattle nearshore. Surf smelt also spawn along several beaches within the Seattle shoreline. Surf smelt and sand lance have specific spawning habitat require- ments, which make them especially vulnerable to shoreline development activities (Lemberg et al., 1997; Pentilla, 1978; Pentilla, 2000). Such activities can result in change in beach elevations and substrate composition, which are critical factors for baitfish spawning. Loss of overhanging riparian vegetation along shorelines may reduce shading and Rip-rap protecting the sea wall on Elliott Bay. Photo by Duncan Kelso 85 Seattle’s Aquatic Environments: Marine Nearshore estuary areas.Thesesubstrate changescaninturn composition inmanymarine nearshoreand can resultinsubstantialchanges tosubstrate reduced alongshoremobilization anddeposition, line. Thelackofsedimentrecruitment, and tion andtransportofsedimentsalongtheshore- rock jettiesandgabionscanreducethemobiliza- spits. Bankarmoringandinwaterstructuressuchas deposition suchasbeaches,headlands,andsand- sediment fromslidesandstreamstoareasof Waves andalongshorecurrents(driftcells)carry sediments tomarinenearshoreandestuaryareas. the Duwamish,furtherreducesavailabilityof Green River,andchannelizationdredgingin shoreline areas.Widespreaddikingofthelower inputs causedbywidespreadbankarmoringalong ably cannotcompensateforthereducedsediment inputs ofsedimentfromstreamsandriversprob- of land-development.However,theincreased nearshore areashasgenerallyincreasedasaresult streams andriversintoestuarymarine of thebiotainthisarea.Sedimentinputsfrom substrate, whichinturn,changesthecomposition strate compositionfromsmallersubstratetolarger silt, sandandgravel),resultinginashiftsub- being “starved”ofasourcesmallsubstrates(i.e., from occurring.Thisresultsinthenearshorearea prevents erosionprocessessuchasbanksloughing prevents damagetoshorelinepropertiesbutalso tion ofriprap(boulder)banksandbulkheads, armoring. Bankarmoring,includingtheconstruc- nearshore environmentbywidespreadshoreline of thesesourceareashavebeenisolatedfromthe eelgrass beds,andothernearshorehabitats.Most critical tothemaintenanceofbeaches,spits,flats, port ofsedimentsfromlandslidesisthoughttobe transport onbiologicalcommunities.Thetrans- the moregeneraleffectsofinterruptedsediment and thereislimitedquantitativeinformationon transport havebeendoneforhabitatsinSeattle, effects ofshorelinedevelopmentonsediment and estuaryareas.Fewquantitativestudiesofthe transport, anddepositionalongmarinenearshore urban developmenthasbeentosedimentinputs, The mostimportantphysicalimpactcausedby line area. nearshore habitatwithinthecityofSeattleshore- tures haveresultedindirectmodificationtothe filling, andtheconstructionofoverwaterstruc- nearshore environment.Bankarmoring,dredging, natural processesthatcreatehabitatwithinthe Human activitieshaveresultedindisruptingthe 86 shoreline areas. steep slopesalongthefewremaining natural remnant deciduousforests growing onbluffsand landscaping inparksandresidential areasand Shoreline riparianareasare generallylimitedto along theSeattleshoreline have beenremoved. detrital inputs.Almostallnativeconiferousforests productivity ofdeeperwaterhabitatsbydecreasing vegetation alongtheshorelinemaydecrease in thenearshoreenvironment.Lossofriparian results inareductionfoodresourcesforforaging beaches (Figure7).Alossofriparianvegetation water andalsoprovidesshadetosmeltspawning sources intheformofinsectsdroppinginto marine systems.Ripariancorridorsprovidefood areas andmayprovideadditionalrolesuniqueto provide functionssimilartofreshwaterriparian Preparation) hypothesizethatmarineriparianareas marine systems.BrennanandCulverwell(In functions andvaluesofriparianvegetationin relatively littleresearchhasbeenconductedonthe importance ofriparianareasinfreshwatersystems, and bluffs.Althoughmuchisknownaboutthe aquatic habitatsanduplandareas,suchasbanks Riparian areasarethetransitionzonesbetween phytoplankton, alsorequiresfurtherstudy. on theproductivityofmarinevegetationand nearshore areas,andthesubsequentimpactsofthis cycling (i.e.,nutrientdynamics)inmarine natural sourcesonnitrogenandphosphorous detrital (organicmatter)inputsfromhumanand (KCDNR, 2001).Theimpactsofnutrientand ever, waterqualitydataislackingformanyareas along themajorityofSeattleshoreline;how- Data indicatesthatwaterqualityisgenerallygood systems arenotrelatedtoactivitieswithinthecity. practices andimproperlyfunctioningseptic water qualityconsiderations,suchasagricultural plays arolerelatedtothecityofSeattle.Some is uncleartowhatextenteachoftheseimpacts juvenile salmonidsbothdirectlyandindirectly.It In generalterms,waterqualityisthoughttoaffect (Brennan andCulverwell,Inpreparation). carrying capacityofthenearshoreecosystem ability, andnutrientsourcesmayeffectthe loss ofhabitatcomplexity,predatorrefugeavail- ations inmarineriparianvegetationcanleadtoa salmon, aswellbaitfishspawningareas.Alter- acclimation habitatareasforjuvenileChinook reduce theavailabilityofcriticalrefuge,forage,and kelp forests.Lossofvegetationmaysubstantially and subtidalvegetationincludingeelgrassbeds result inthereductionoreliminationofintertidal Seattle’s Aquatic Environments: Marine Nearshore

Marine Nearshore Diagram

Urban Landscape Habitat Habitat Population Constraints Processes Processes Requirements Functions

Land Sediment Sources Development (bank sloughing) Shallow Intertidal Habitat Shoreline (beaches, flats) Nearshore Formation/ Bulkheading Juvenile Currents Maintenance Predator and Armoring Survival (drift cells) Avoidance Eelgrass Beds Shelter/Cover Overwater Wave Action Juvenile Structures and Patterns Kelp Forests Food Growth and Condition Terrestrial Deep (Offshore) Habitat Dredging Riparian Vegetation Insect Inputs Predator Subadult / Adult Benthic Avoidance Growth and Stream / River Condition Modifications Nutrient Invertebrate Cycling Production Baitfish (food) Sewage Zooplankton Outfalls Organic Matter Production Inputs Non-point Water Quality Contaminants

Figure 7. Hierarchical relationships between urban constraints, landscape processes, habitat requirements, and population functions for Chinook salmon in the marine nearshore.

87 Seattle’s Aquatic Environments: Marine Nearshore factors forjuvenileChinooksurvivalandfitnessinnearshoreareas. Based ontheanalysisabove,followingtablesummarizesourunderstandingofmostsignificant ucinFnto odto omn rcse Constraints formingprocesses Habitat condition Habitatcharacteristic/ Function Habitat Function Population diversity, andmarinevegetation emergeasakeyareaoffocus. Among thesefactors,theprotectionandrestoration ofbeachformingprocesses,habitat Foraging and Adult Subadult saltwater transition to Juvenile outmigration rearing and Juvenile production Baitfish Water Brackish Access Quality Water Availability Food Avoidance Predator substrates forbaitfish proper spawning Shallow areaspossessing areas in estuaryandnearshore Freshwater mixingzones are uncertain) structures onmigration impacts ofpiersandother No barriers(potential under investigation) contaminant impacts uncertain (sediment Impacts ofcontaminants quality Generally goodwater distribution Spatial /temporal Kelp forests Eelgrass beds (sand, cobbles) shallow shorelineareas Diverse substratesin channels inestuaries) sloughs, anddistributary (including sidechannels, Off-channel habitats (eelgrass beds,kelpforests) Marine vegetation beds) beaches, tidalflats,eelgrass Shallow water(e.g., Preliminary Focus Areas 88 production Zooplankton andbenthic Organic mattercycling from riversandstreams Freshwater outflows timing Tide magnitudeand sediments. contaminants by Adsorption of upstream Quality ofsourcewaters algae growth Aquatic macrophyteand insect inputs) (increases terrestrial Riparian vegetation from riveroutflows Organic mattertransport (vegetation growth) Nutrient cycling erosion andtransport) Wave action(bank (sediment transport) Nearshore currents pattern Tidal magnitudeand erosion, riverineinputs) Sediment sources(bank Loss ofeelgrassbeds substrate changes) bulkheading (resultsin Bank armoringand freshwater outflows) diversions (reduce Upstream damsand freshwater inputs magnitude ofmajor Altered routingand population andlanduses High densityhuman Loss ofriparianvegetation (e.g., eelgrassbeds) Loss ofmarinevegetation Overwater structures Dredging andfilling bulkheading Bank armoringand Seattle’s Aquatic Environments: Marine Nearshore

Habitat Improvement Projects in the Nearshore

Project Name Project Cost or Habitat Requirement estimate Predator Food Baitfish Status of Project Project Description Avoidance Availability production

Cormorant Cove: Riprap was moved inland to create a Shallow Habitat Shoreline small beach cove. Upland edge of rip water habitat diversity improvement rap was planted with native shrubs and grasses. $300,000

Completed

Elliott Bay Oyster shell, cobble and rock substrate Shallow Habitat Marine Near Shore was placed in the subtidal zone. water habitat diversity vegetation Enhancement

$327,000

Completed

Golden Gardens: Construction of the RR to the north Restoration Habitat Renourishment eliminated the sediment delivered to the of beach diversity beach by littoral drift Gravel materials forming $1,000,000 added to north and west portions of the processes point. A low rock groin was constructed Completed at the north part and a feeder berm for gravel at the south part. Backshore dune and wetlands landward of beach berm were added, and stormwater mgt. was improved.

Lincoln Park: Sea wall constructed in 1934 caused Restoration Beach erosion along with loss of littoral drift of beach Renourishment in sea wall. In 1988, 20,000 cubic yds. forming of sand and gravel were placed along processes Completed 1/2 mile of shoreline in front of sea wall. Extensive biological monitoring was performed pre- and post- construction, as well as pre- and post- renourishment of the beach in 1994. The renourishment involved placement of 5,000 cubic yards of beach materials. Drift logs and dune grasses have become established along the beach in recent years.

89 Seattle’s Aquatic Environments: Marine Nearshore Completed Renourishment Beach West Point: Completed Renourishment Seacrest Beach Potential Outlet Relocation Schmitz Creek Potential Protected Area Potential Marine Golden Gardens: Pipers Creekto Potential as $1,000,000 $200,000 toasmuch Park Myrtle Edward’s Completed $300,000 improvement Shoreline Lowman Beach : : and plantedwithbeachgrass. band ofbackshorewasenhancedw/sand wide along3000ft.ofbeach.A40 and gravelwereplacedinaband90ft. littoral drift.58,000cubicydsofsand of sewagelagoonin1962thatblocked Eroded shorelinecausedbyconstruction Renourishment in1997. pocket beachesandalongtopofriprap. planted inbackshoreareasbehindthe to stabilizegravel.Beachgrasswas Reconfigured riprapusedatcoveedges adding graveltoexistingcovesin1989. Three pocketbeacheswerecreatedby juvenile feeding. nutrients totheshallowwaterzonefor back toshallowwaterbringterrestial offshore outfall.Couldmoveoutfall and thenispipedtoPugetSoundwithan Schmitz Creekentersasedimenttrap marine protectedarea. Citizens groupseekingspecialstatusasa park. expand theshallowintertidalareaat south behindtheexistingrip-rapto could beextendedinlandandtothe restoration studies.Theexistingbeach been thesubjectoftwopreviousbeach the PortofSeattle’sElliottBayPark)has the park(orbetweencity’sand The smallbeachcoveatthenorthendof replaced withasmallpocketbeach. A faultyportionoftheseawallwas 90 processes forming of beach Restoration processes forming of beach Restoration processes forming of beach Restoration diversity diversity diversity diversity diversity Habitat Habitat Habitat Habitat Habitat vegetation Marine Seattle’s Aquatic Environments: Marine Nearshore

Addressing Uncertainties Literature Cited The importance of marine nearshore areas to Blomberg, G., C. Simenstad, and P. Hickey. 1988. Chinook salmon is poorly understood beyond a Changes in Duwamish River estuary habitat few studies. In the longer term, a significant body over the past 125 years. Pages 437-454 In: of research is needed to address how, and to what Proceedings of the First Annual Meeting on extent, specific nearshore areas within the city Puget Sound Research. Volume II. Puget influence the survival, growth, and condition of Sound Water Quality Authority, Seattle, Puget Sound Chinook. Washington. Key research and assessment issues include: Brennan, J., and H. Culverwell. In prep. Marine riparian: An assessment of riparian func- 1. Determine the presence, distribution, and tions in marine ecosystems. Working draft. periodicity of juvenile Chinook within marine King County Department of Natural nearshore and estuary habitats; Resources, Seattle, Washington. 2. Identify preferences in nearshore areas by Cederholm, C. J., D. H. Johnson, R. E. Bilby, L. juveniles and sub-adults for specific types of G. Dominguez, A. M. Garrett, W. H. habitat; Graeber, E. L. Greda, M. D. Kunze, B. G. 3. Identify potential impacts of predation on the Marcot, J. F. Palmisano, R. W. Plotnikoff, survival and habitat use of juvenile Chinook W. G. Pearcy, C. A. Simenstad, and P. C. salmon migrating and rearing in nearshore Trotter. 2000. Pacific salmon and wildlife: areas; Ecological contexts, relationships, and implications for management. Special 4. Evaluate the effects of overwater structures on Edition Technical Report, prepared for D. predator abundance and efficiency, the distribu- H. Johnson and T. A. O’Neil (Manag. Dirs.), tion of submerged vegetation including eelgrass Wildlife-Habitat Relationships in Oregon beds, and food availability; and Washington. Washington Department 5. Identify and evaluate the use of specific of Fish and Wildlife, Olympia, Washington. nearshore areas within the city by forage fish Chrzatowski, Michael. Historical Changes to Lake species used by subadult and adult Chinook; Washington and Route of the Lake Washing- ton Ship Canal, King County, Washington. 6. Evaluate long-term water and sediment quality Department of the Interior, United States trends near Seattle and the effect of water Geological Survey. Water Resources Investi- quality issues in the marine nearshore on gation Open File Report 81-1182. Chinook. Fresh, K. L., R. D. Cardwell, and R. P. Koons. 1981. Food habits of Pacific salmon, baitfish, and their potential competitors and predators in the marine waters of Washing- ton, August 1978 to September 1979. Progress Report No. 145. Washington Department of Fisheries, Olympia, Washing- ton. Healy, M. C. 1982. Juvenile Pacific salmon in estuaries: The life support system. Pages 315- 341 in Kennedy, V. S., editor. Estuarine comparison, Academic Press, New York, New York.

91 Seattle’s Aquatic Environments: Marine Nearshore Pentilla, D.1978.Studiesofthesurfsmelt Pearce, T.A.,J.H.Meyer,andR.S.Boomer. Myers, J.M.,R.G.Kope,Bryant,D.Teel,L. Lynn, B.,1998.NearshoreHabitatLossinPuget Levy, D.A.andT.G.Northcote.1982.Juvenile Levings, C.D.,R.E.Foreman,andV.J.Tunnicliffe. Lemberg, N.A.,M.F.O’Toole,D.E.Penttila, King CountyDeptofNaturalResources ton. Department ofFisheries,Olympia, Washing- Technical ReportNo.42. Washington ( (Unpublished report). Wildlife Service,Olympia,Washington. Washington, 1979-1980.U.S.Fishand juvenile salmonidsintheNisquallyEstuary, 1982. Distributionandfoodhabitsof istration. National OceanicandAtmosphericAdmin- Technical MemorandumNMFS-NWFSC-35. ton, Idaho,Oregon,andCalifornia.NOAA review ofChinooksalmonfromWashing- Lindley, andR.S.Waples.1998.Status Grand, F.W.Waknitz,K.Neely,S.T. J. Lierheimer,T.C.Wainwright,W.S. Georgia BasinInternationalTaskForce. Habitat LossWorkgroup,PugetSound/ Management. WashingtonNearshore Sound: RecommendationsforImproved Fisheries andAquaticSciences39:270-276. Fraser RiverEstuary.CanadianJournalof salmon residencyinamarshareaofthe Aquatic Sci.40(7):1120-1141. Georgia andcontiguousfjords.Can.J.Fish. 1983. ReviewofthebenthosStrait Wildlife, Olympia. 98-1. WashingtonDepartmentofFishand stock statusreport.StockStatusReportNo. ment ofFishandWildlife,1996foragefish and K.C.Stick.1997.WashingtonDepart- Resources. KCDNR,Seattle,Washington. ates forKingCountyDept.ofNatural Environmental Associates,ShapiroAssoci- Laboratory, PentecEnvironmental,Striplin Report preparedbyBattelleMarineSciences (WRIAs 8and9).FinalReviewDraft. Sound, includingVashonandMauryIslands ecosystem: easternshoreofcentralPuget (KCDNR). 2001.Stateofthenearshore Hypomesus

pretiosus ) inPugetSound. 92 Williams, G.D.andR.M.Thom.inprep. Weitkamp, D.,G.Ruggerone,L.Sacha,J.Howell, Wallace, M.andB.W.Collins.1997.Variationin Shepard, M.F.1981.Statusandreviewofthe Pentilla, D.E.2000.Impactsofoverhanging Department ofTransportation,(Draft). issues. PreparedfortheWashingtonState Marine andestuarineshorelinemodification 224 p. Associates fortheCityofSeattle,June2000. Resources Consultants,andCedarRiver Prepared byParametrixInc.,Natural Chinook Populations,BackgroundReport. and B.Bachen.2000.FactorsAffecting 83(4):132-143. Chinook salmon.CaliforniaFishandGame use oftheKlamathRiverEstuarybyjuvenile ton, Seattle. College ofFisheriesUniversityWashing- Cooperative FisheriesResearchUnit, Puget Sound.FinalReport.Washington chum andChinooksalmonjuvenilesin habitat requirementsandlifehistoryof knowledge pertainingtotheestuarine (Draft). and Wildlife,Olympia,Washington. Division, WashingtonDepartmentofFish Sound, Washington.MarineResources upper intertidalbeachesinNorthernPuget summer-spawning surfsmelt, shading vegetationoneggsurvivalfor Hypomesus , on