Download - Understanding Pesticides in California’s Delta · Fact Sheet 2012–3132. Printed on recycled paper November 2012. Understanding Pestici. des in California’s Delta. Delta Watershed:

SacramentoSacramento

San FranciscoSan Francisco

Sacramento River

Sacramento River

San Joaquin River

San Joaquin River

U.S. Department of the InteriorU.S. Geological Survey

Fact Sheet 2012–3132November 2012Printed on recycled paper

Understanding Pesticides in California’s Delta

Delta Watershed:

• 6millionpeople(2009estimate).

• 4millionacresagriculturalland.

• 400pesticidesappliedfortotalof10millionpoundseachyear.

DecadesofUSGSresearchhaveprovidedagoodunderstandingofwhen,where,andhowpesticidesentertheDelta.However,pesticideuseiscontinuallychanging.NewfieldstudiesandmethodsareneededsothatscientistscananalyzewhichpesticidesarepresentintheDelta,andatwhatconcentrations,enablingthemtoestimateexposureandultimateeffectsonorganisms.ContinuingresearchwillprovideresourcemanagersandstakeholderswithcrucialinformationtomanagetheDeltawisely.

Pesticide Sources

• Pesticidesareappliedinagriculturalandurbanareastocontrolunwantedinsects,plants,andfungi.

• Theamountandtypeofpesticidesusedchangesaspesticidesarewithdrawnfromthemarket,croppingpatternsandpestpressureschange,andnewchemicalsaredeveloped.

• Pesticideapplication,followedbyrunofffromrainorirrigation,createswell-definedseasonalpatternsofpesticideconcentrationsinDeltawaterchannels.

• WaterscarryingpesticidesentertheDeltafromtheSacramentoandSanJoaquinRivers,YoloBypass,surroundingcreeks,andwithin-Deltalands.

• ChangingwateruseandclimateaffectpesticideinputandtransportthroughtheDelta.

TheSacramento-SanJoaquinRiverDelta(Delta)isthehubofCalifornia’swatersystemandalsoanimportanthabitatforimperiledfishandwildlife.AquaticorganismsareexposedtomixturesofpesticidesthatflowthroughthemazeofDeltawaterchannelsfromsourcesincludingagricultural,landscape,andurbanpest-controlapplications.Whilewedonotknowalloftheeffectspesticideshaveontheecosystem,thereisevidencethattheycausesomedamagetoorganismsintheDelta.

WINTEROrchardsRainfall

SPRINGAlfalfa

Rainfall & Irrigation

SPRING-SUMMERRice

Field Water ReleaseSUMMER

Row/Truck CropsIrrigation

How do Pesticides Move into the Water?

Res

ulting in Distinct Seasons of Pesticide Occurrence

PESTICIDES ARE APPLIED

THEN TRANSPORTED BY WATER AND SEDIMENTS

INTO WATERWAYS

ALL YEARUrban Use

Rainfall & Irrigation

How Are Living Organisms Affected?Pe

stic

ide

Conc

entra

tion

Short time at high concentration

Long time at low concentration

Time

EXPOSURE = CONCENTRATION * TIME

CH2 Cl

S

O

N

CH3

H2C

H3C

H3C

CH2CH3

N

CH3

CHCH 2OCH 3

COCH 2CI

CH3

N

S

O

CH2

CH3

PESTICIDES Causes mortality or decreases growth

Changes quantity or quality of food

Direct Effects

Indirect Effects

ORGANISMS LIVING IN THE DELTA ARE EXPOSED TO

PESTICIDES

EFFECTS CAN BE DIRECT OR INDIRECT

Bothpesticideconcentrationandthelengthoftimethatanorganismisexposedtoapesticidedeterminetheeventualeffectithasontheorganism.SomepesticidesmovethroughtheDeltaquickly(hourstodays),butarepresentathighconcentrations.Otherpesticidesarepresentforlongerperiods(weekstomonths),butatmuchlowerconcentrations.Bothtypesofexposurecanaffectanorganism,soitisimportanttoknowspecificenvironmentalpesticideconcentrationsanddurations.

Themostobviouseffectofpesticideexposureonorganismsisdeath,usually,asaresultofdirectexposuretohighconcentrationsofpesticidesoverashorttime.But,exposuretolowerconcentrationsoveralongertimecanbejustasdeadly.Decreasedgrowth,impairedreproduction,andinhibitionofswimmingperformancecanalldiminishpopulationsize.Pesticidesintheenvironmentcanalsohaveindirecteffects,whichresultinproblemssuchasreductioninavailabilityorqualityoffood.

USGS Pesticide Fate Research Group

Waterisanalyzedbecausethisiswheremostanimalslive.Sedimentsareimportantfororganismsthatlivein,oratthebottomof,streams.Pesticidescanalso“moveupthefoodchain”asorganismseatanimalsorplantsthathavealreadyaccumulatedpesticides.Togainamorecompleteviewofenvironmentaleffectsofpesticidesonorganisms,weanalyzewater,sediments,andanimaltissue.

Effectivepesticideanalysisrequirespersistentmethoddevelopmentandresearch.TheUSGSPesticideFateResearchGroupisaleaderincurrent-usepesticidescience.ResearchersfrequentlyaddnewcompoundstoUSGSmethodstokeepupwithchangingpesticideuseandnewenvironmentalconcerns.Laboratorymethodsaresensitiveenoughtopreciselyandaccuratelymeasurepesticideconcentrationlevelsthatareverylowbutthatstillmayaffectlivingorganisms.

Authors:KathrynM.Kuivila,[email protected],andJamesL.Orlando,[email protected]

Contact:CaliforniaWaterScienceCenter;6000JStreet,PlacerHall;Sacramento,CA95819http://ca.water.usgs.gov/

For More Information:http://ca.water.usgs.gov/projects/toxics/DesignedbyYvonneRoque

Reference: Kuivila,K.M.andHladik,M.L.,2008.Understandingtheoccur-renceandtransportofcurrent-usepesticideintheSanFranciscoEstuaryWater-shed,SanFranciscoEstuaryandWatershedScience,v.6(3),article2.

Science to Help Resource ManagersSummarizing Our Current Understanding of Pesticides in the DeltaFourmajorseasonalpatternsofriverineinputsofpesticidestotheestuarywereidentifiedonthebasisofapplicationtimingandtransportmechanism.Incontrast,urbaninputstookplacethroughoutmuchoftheyear.Identifieddatagapsincludedthelackofanalysisofmanypesticides(ordegradates),changingpesticideuse,limitedinformationonpesticidetransportwithintheDelta,andanincompleteunderstandingofthetransportandpersistenceofsediment-associatedpesticides(KuivilaandHladik,2008).

State-of-the-ArtAnalyticalLaboratory

Proven Field SamplingMethodsUnderstanding

of Delta Hydrology

Knowledge of Pesticide-Use

Practices

Knowledge of Chemical

Processes

Continuing to Conduct Focused Research on PesticidesADAPTING TO CHANGING USEAspesticideusechangesandnewchemicalscomeonthemarket,thetimingandconcentrationsofpesticidesenteringtheDeltawillchange.Routinemonitoringandadvancedmethodstoanalyzenewpesticidesprovidecurrentinformationonthecomplexmixtureofpesticidespresentintheecosystem.

EVALUATING PESTICIDE FATEPesticidesenteringtheDeltacanbedissolvedinthewaterorattachedtosediments,andcanalsodegradetonewcompoundsofpotentialconcern.Focusedfieldandlaboratorystudiesprovideinformationonthefactorscontrollingtheseprocesses,whichinturninfluencethetransportandpersistenceofpesticides.

ASSESSING FISH EXPOSUREInthecomplexDelta,itisdifficultandexpensivetoadequatelycharacterizefishexposurebymeasuringpesticideconcentrationsinwaterandsediments.Adifferentapproachisto“askthefish”bydirectlyanalyzinglevelsofpesticidesandtheirmetabolitesinfishtissuewithsensitiveanalyticalmethods.

Through ongoing collaborations with toxicologists, ecologists, and fisheries biologists, we can address questions of concern such as “how do pesticides affect native fish populations in the Delta and the ecosystem as a whole?”

Using Our Expertise to Address Data Gaps