CONSERVATION BIOLOGY PROGRAM Summary Report: Green Sturgeon, Longfin Smelt, and Dredging Operations in the San Francisco Estuary Prepared for U.S. Army Corps of Engineers by Bronwen Stanford, Kat Ridolfi, and Ben Greenfield San Francisco Estuary Institute CONTRIBUTION NO. 598 SAN FRANCISCO ESTUARY INSTITUTE 7770 Pardee Lane, Second floor, Oakland, CA 94621 DECEMBER p: 510-746-7334 (SFEI), f: 510-746-7300, www.sfei.org 2009 Thisreportcanbecitedas:Stanford,B.,K.Ridolfi,andB.Greenfield,2009.Summary Report:GreenSturgeon,LongfinSmelt,andDredgingintheSanFranciscoEstuary. PreparedfortheU.S.ArmyCorpsofEngineers.SFEIContribution#598.SanFrancisco EstuaryInstitute,Oakland,CA. TABLEOFCONTENTS 1.ABSTRACT................................................................................................................1 2.ACKNOWLEDGEMENTS........................................................................................2 3.INTRODUCTION......................................................................................................3 4.GREENSTURGEON.................................................................................................6 4.1.Managementhistoryandcurrentstateofknowledge.........................................6 4.1.1.Greensturgeonbiologyandecology..........................................................8 4.1.2.Impactsofdredging..................................................................................10 4.2.Concernsofstakeholders..................................................................................14 4.3.Futureresearchandrecommendations..............................................................14 5.LONGFINSMELT...................................................................................................17 5.1.Managementhistoryandcurrentstateofknowledge.......................................17 5.1.1.Longfinsmeltbiologyandecology..........................................................17 5.1.2.Impactsofdredging..................................................................................19 5.1.3.Otherpotentialthreatstolongfinsmelt....................................................22 5.2.Concernsofstakeholders..................................................................................23 5.3.Futureresearchneeds,andpotentialsolutions.................................................24 6.NEXTSTEPS...........................................................................................................26 7.REFERENCES.........................................................................................................28 1. ABSTRACT In2009,CaliforniaDepartmentofFishandGameCommissionlistedlongfinsmelt (Spirinchusthaleichthys )asthreatened,andNOAAformallyadopted“take”provisions forgreensturgeon( Acipensermedirostris Ayres).Thesechangesinthemanagement status,andassociatedpermittingissues,havepromptedrenewedinterestamongLTMS participantsinthemanagementofthesenativefish.Inresponse,LTMSheldsymposia onDecember2and3,2009,toreviewandconsiderthescience,management,andpolicy relatedtodredgingactivitiesandthesespecies.Aprimarystressortobothspeciesis reductionofappropriatehabitat,duetowaterdiversionactivitiesandotherbasin-scale modificationsinwaterflow.Localstudiesofdredginghaveshownlittleevidenceof directentrainmentforeitherspecies,andthefrequencyofencounterwithsitesof dredgingactivityislikelytobeverylow.Nevertheless,spatialandtemporalpatternsof populationmovementsandreproductiveactivityvaryfromyeartoyear,makingit difficulttoemployanenvironmentalworkwindowsapproach.Availableinformationis limitedonotherdirecteffectsofdredging,includingsedimentcontamination,habitat modification,andunderwaternoise.Indirecteffectsduetomaintenanceofactive navigationchannelsposepotentialconcerns.Inparticular,introductionofinvasive species,andmortalityduetopropellerstrikes,bothwarrantattention. Asafollowupsteptothesymposia,werecommendthatLTMShostaworkshoptargeted towardsspecificLTMSmanagementneedsforgreensturgeonandlongfinsmelt.The workshopshouldincludeLTMSparticipants,thescientiststhatpresentedatthe symposium,anddredgingoperators,andcouldfocusontheintegrationofcurrent researchfindingsintotoolsthatwouldbeusefulformanagers.Appropriatetoolsfor considerationincludepredictiveordescriptivemodelsofspeciesdistribution,andof potentialimpactsofvariousdredgingactivities.Thereshouldalsobeconsiderationof managementapproachesthatbroadlyaddresstheprimaryecosystem-levelstressorsfor greensturgeonandlongfinsmelt,ratherthanemployingsmallscaleproject-level mitigation.Inparticular,anintegratedregionalrestorationandmonitoringprogrammay bethemosteffectiveapproachtoimprovethehealthofthespecies. 1 2. ACKNOWLEDGEMENTS WethankChristineWermefordevelopingbackgroundmaterialandconceptsusefulin developmentofthisreport.JoanneCablingandLindaWanczykassistedwithgraphic design,includingthereportcoverpagegraphics.Theconferenceplanningcommittee, includingBillBrostoff,DavidWoodbury,PeteLaCivita,andGeorgeIsaac,provided conceptualguidanceandrecommendationsondevelopmentoftheconferenceprogram andcontent.ConstructivesuggestionswerealsoprovidedbyBrendaGoeden,Ellen Johnck,JessicaHamburger,andBrianRoss.Theresearchsummariesinthisreportwere derivedfromthepresentationsprovidedbyPeteKlimley,MikeThomas,AlexHearn, CynthiaFowler,MikeParsley,AndrewCohen,StephaniaBolden,DavidWoodbury,Josh Israel,DougClarke,TracyCollierRandyBaxter,JimHobbs,JonathanRosenfield, JordanGold,JenniferDeLeon,JohnZentner,andBrianSwedberg.Readersare encouragedtoconsulttheoriginalpresentationsforfurtherinformation,availableonthe webat http://www.sfei.org/cb/greensturgeon .Wealsothankthestakeholderparticipants fortheirinputatthesymposium:AnneWhittington,J.T.Wick,DavidWoodbury,Tom Gandesbery,LenCardoza,B.K.Cooper,andRainerHoenicke.Constructivereview commentsonpreviousdraftsofthisreportwereprovidedbyThomasJabusch,Rainer Hoenicke,BillBrostoff,MikeParsley,AndrewCohen,JoshIsrael,andDavidWoodbury. ThisworkwasfundedbytheU.S.ArmyCorpsofEngineersLTMS. 2 3. INTRODUCTION 1 TheLong-TermManagementStrategyforthePlacementofDredgedMaterialintheSan FranciscoBayRegion(LTMS)providesacooperativeframeworkformaintainingthe navigationchannelsoftheSanFranciscoEstuaryinaneconomicallyand environmentallysoundmanner.LTMSisanongoingcollaborationofmultiple participants 2. Inordertogainabetterunderstandingofhowdredgingimpactstwospeciesofconcern, NorthAmericangreensturgeon( Acipensermedirostris Ayres)andlongfinsmelt (Spirinchusthaleichthys ),theU.S.ArmyCorpsofEngineers(USACE)fundedtheSan FranciscoEstuaryInstitute(SFEI)toholdtwosymposiatoevaluateanddisseminatethe latestavailableinformationonthesespecies.Theobjectivesofthesymposiawereto: Disseminatecurrentknowledge, Reviewguidelinesneededtomanagethesespeciesandcomplywithrelevant regulatorymandates;and Developstudyplansforfurtherwork. ThesymposiawereheldonDecember2and3,2009,inOakland,CA,withoneday dedicatedtoeachspecies.Therewereover100participants,includingscientists, regulators,representativesfromthedredgingcommunity,andotherinterestedparties. Thesymposiaalsoincludeddiscussionsofthevariousmanagementoptionsforthese specieswithrespecttodredgingoperationsintheregion,suchasthedredgingwindow policy.Thisbriefreportsummarizesthemajorfindingsanddiscussionsofthesymposia, includingthecurrentstateofknowledge,managementhistoryofthespecies,potential impacts(bothdirectandindirect)ofdredging,prioritiesandissuesidentifiedby stakeholders,andfutureresearchrecommendations. Inthepastfewyears,decliningpopulationsofgreensturgeonhaveincreasedawareness ofthespecies,andresultedinlocalresearchstudies,includingbothpublishedliterature andunpublishedstudies(Armoretal.2006,Klimleyetal.2007).Thishasincluded taggingstudiesperformedbyCaliforniaexpertsinthefield,fundedbyLTMS.The southerndistinctpopulationsegment(DPS)ofNorthAmericangreensturgeon (Acipensermedirostris Ayres)waslistedas“threatened”byNOAAFisheriesunderthe FederalEndangeredSpeciesAct(ESA)in2006.Threeyearslater,inMay,2009,NOAA Fisheriesproposedarulingtoapply“take”provisionsforthispopulation.Green 1 ThisIntroductionispartiallybasedonpriorprojectdocuments,includingtheprojectConceptProposal, draftedbyChrisWerme,anindependentconsultant,andtheSFEIresponsetotheprojectRFP 2 AgencyparticipantsincludetheNationalOceanicandAtmosphericAdministration(NOAA)National MarineFisheriesService(NOAAFisheries),theCaliforniaDepartmentofFishandGame(CDFG),the U.S.ArmyCorpsofEngineers(USACE),U.S.EnvironmentalProtectionAgency(EPA),Bay ConservationandDevelopmentCommission(BCDC),StateWaterResourcesControlBoard(SWRCB), andotherlocalagencies.Stakeholderparticipantsincludedredgingcontractors,municipalitiesandprivate entitiesthatperformdredgingactivities,andprivateandpublicentitiesthatprocuredredgedsedimentsfor habitatrestorationandotherbeneficialreuses. 3 sturgeonsoutsideoftheBay-Deltaregionhavealsosufferedpopulationdeclines.For example,theyarelistedas“rare”inCanada(Moyle2002). Lessresearchhasbeenconductedonlongfinsmelt,thoughCDFGsurveydataindicate thatthelongfinsmelthasdeclinedsubstantiallysincethe1980s(RosenfieldandBaxter 2007,CaliforniaDepartmentofFishandGame2009).InJanuary2009,theCalifornia DepartmentofFishandGame(CDFG)listedlongfinsmeltas“threatened”underthe CaliforniaEndangeredSpeciesAct(CaliforniaDepartmentofFishandGame2009). TheCaliforniaESA(CESA)isverysimilartothefederalESAinmanyways(e.g.the listingprocessandthedefinitionoftake)althoughtherearesomedifferences.Thestate ESAprotectsonlyspeciesandlimits“take”withintheboundariesofthestate,whilethe federalESAalsoprotectsdistinctpopulationsandcanlimittakewithinadefinedareaof criticalhabitatforthepopulation.CESAismorestringentthanthefederalESAintwo