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Monitoring Cruise at the Morris Cove Borrow Pit Disposal Area Monitoring System DAIVIOS DATA library] WoodsHole Oceanographiclnsiitution J&-^ D A M O 8 DISPOSALAREAMONaORINSSYSTEM Contribution 129 June 2001 US Army Corps of Engineers <b New England District "— :utjrr^j 1i _D CaD .J^^^^ CgD^^""^^^ 1°-^ m ^^o 11 o ^^^^^^S^S^ ^^^^^J REPORT DOCUMENTATION PAGE formapproved OMB No. 0704-0188 Publicreportingconcernforthecollectionofinformationisestimatedtoaverage1hourperresponseincludingthetimeforreviewinginstructions, searchingexistingdatasources,gatheringandmeasuringthedataneededandcorrectingandreviewingthecollectionofinformation. Sendcomments regardingthisburdenestimateoranyotheraspectofthiscollectionofinformationincludingsuggestionsforreducingthisburdentoWashington HeadquartersServices,DirectorateforinformationObservationsandRecords, 1215JeffersonDavisHighway, Suite 1204,Arlington VA22202-4302 andtotheOfficeofManagement andSupport, PaperworkReduction Project(0704-0188),Washington,D.C.20503. 1.AGENCYUSEONLY (LEAVEBLANK) 2.REJuPnOeR20T01DATE 3.REPORTTFYIPNEALARNEDPODRATTESCOVERED 4.TITLEANDSUBTITLE 5.FUNDINGNUMBERS MonitoringCruiseattheMorrisCoveBorrowPit 6.AUTHOR(S) ScienceApplicationsInternationalCorporation 7.PERFORMINGORGANIZATIONNAME(S)ANDADDRESS(ES) 8O.RPGEARNFIOZRAMTIINOGN REPORT ScienceApplicationsInternationalCorporation NUMBER 221 ThirdStreet Newport,Rl02840 SAICNo.520 9.SPONSORUISNAGr/mMyONCoIrTpOsRoIfNEGngAiGneEeNrCs-YNeNwAMEEn(glSa)nAdNDiDstAriDcDtRESS(ES) A10G.ESNPOCNYSROERPIONRG/TMNOUNMIBTOERRING 696VirginiaRd DAMOSContributionNumber129 Concord,MA 01742-2751 SUPPLEMENTARYNOTES 11. AvailablefromDAMOSProgramManager,RegulatoryBranch USACE-NAE,696VirginiaRd,Concord,MA01742-2751 12a.DISTRIBUTION/AVAILABILITYSTATEMENT 12b.DISTRIBUTIONCODE Approvedforpublicrelease;distributionunlimited 13.ABSTRACT DuringJanuaryandMay2000,anestimatedtotalof14,200m'ofsedimentdredgedfromtheU.S.CoastGuardBaseinNewHaven,CTwasplacedinasmall,man-made depression(borrowpit)inMorrisCove,locatedinouterNewHavenHarbor. AmonitoringsurveywasconductedovertheMorrisCoveborrowpitinlateSeptember2000 todocumentthedistributionofthedredgedmaterialontheseafloor,verifythestabilityofthesedimentdeposit,andevaluaterecolonizationofthedepositbybenthic ocorngdaintiisomnss.wTithheinmoannidtoardijancgeinntvtoolvtehdebtoherruoswepoift.RESeMdiOmTenSt®-prsoefdiilmeenitm-apgroefsilaelsiomwaegriengo,btsaidien-esdcaatnasorneafre,resnicneglaer-eabelaomcabtaetdhyampeptrroyx,imaantdeltyow8e0d0vmidweeosttooefvtahleuabtoerbreonwthpiictto provideacomparisonwithambientseafloorconditions. Theside-scansonardatashowedacleardifferentiationbetweensoftersedimentswithintheborrowpitandcoarser,morecompactsedimentscompnsingtheouterwallsof thepit. Multiplebottomfeatureswithincreasedverticalreliefandsurfaceroughnessdetectedwithina50mradiusofthecentraldisposalpointandtotheeastofthispoint wereattributedtodredgedmaterialdeposition. Boththeside-scansonarandtowedvideodatasuggestedthattheimpactsassociatedwiththedepositionofdredged materialwerecontainedlargelywithinthesouthernportionoftheMorrisCoveborrowpit. Thecontrolledplacementofsmallbargeloadsofdredgedmatenalhad facihtatedthecreationofasmall-scalesedimentdepositwithintheconfinesofthepit. TheREMOTS®sediment-profileimagesservedtoconfirmthepresenceofdredged matenalatstationslocatedwithintheborrowpit. Thedredgedmaterialwasobservedatstationsincloseproximitytothedisposalbuoypositionandextendingout100to 150mfromthiscentraldisposalpoint. Themeasuredthicknessofthedredgedmateriallayertypicallyexceededthepenetrationdepthofthesediment-profilecamera(i.e., greaterthanabout10or15cm). Thedredgedmaterialwaspredominantlyfine-grained,consistingofsoft,sandysilt. Thepresenceofmethanegasbubblesinthesedimentatthreestationswithintheborrowpitsuggestedthatsomeofthedredgedmaterialcontinuestocontainahigh inventoryoforganicmatter. Fine-grainedsedimentshavingrelativelyhighsurfaceboundaryroughness,shelllagdeposits,andshallowdepthofaerationcharacterized thereferencearea. Itwashypothesizedthattheshallowreferenceareamayexperienceperiodicphysicaldisturbancefromfishingactivitiesorthescouringactionofwaves andcurrentsdurmghighwindevents. Atthetimeofthesurvey(5monthspostdisposal),itappearedthatbenthicrecolonizationofthedredgedmaterialdepositwasprogressingasexpected. Thesediment- profileimagesshowedthatthebenthicinfaunaincludedprimarilyStageIopportunisticpolychaetes(i.e.,pioneeringtaxa)atthesedimentsurface. Relatively well-developedredoxdepthswerenotedatmoststations,andadvancedsuccessionalstages(StagesIIand/or111)wereobservedat8ofthe22stationsoccupied. Dueto theprotectednatureoftheborrowpitandtherecentinputoforganicallyenrichedsediment,overallbenthichabitatqualitywithintheborrowpitwasconsideredtobe betterthanthatatthenearby,shallowreferencearea. 14.SUBJECTTERMS MorrisCove,NewHavenHarbor,BorrowPit,DredgedMaterial 15.NUMBEROFTEXTPAGES: 38 16.PRICECODE 17.SECURITYCLASSIFICATIONOF 18.SECURITYCLASSIFICATION 19.SECURITYCLASSIFICATION 20.LIMITATIONOF REPORT Unclassified OFTHISPAGE OFABSTRACT ABSTRACT MONITORING CRUISE AT THE MORRIS COVE BORROW PIT CONTRIBUTION #129 June2001 ContractNo. DACW33-00-D-0001 SAICReportNo. 520 Submittedto: RegulatoryBranch NewEnglandDistrict U.S. ArmyCorpsofEngineers 696VirginiaRoad MA Concord, 01742-2751 Submittedby: ScienceApplicationsInternationalCorporation Admiral'sGate 221 ThirdStreet Newport,RI02840 (401)847-4210 USArmyCorps ofEngineers® NewEngland District TABLE OFCONTENTS Page LISTOFTABLES iii LISTOFHGURES iv EXECUTIVE SUMMARY vi LO OBJECTIVEOFTHEMONITORINGSURVEY 1 2.0 METHODS 4 3.0 RESULTS 13 3.1 Side-scan Sonar 13 3.2 REMOTS®Sediment-ProfileImaging 13 3.2.1 Dredged Material Distribution andPhysical Sediment Characteristics 18 3.2.2 Biological ConditionsandBenthicRecolonization 22 3.3 Towed Video Survey 28 3.3.1 SedimentComposition 28 3.3.2 BenthicMacrofauna 36 4.0 CONCLUSIONS 37 5.0 REFERENCES 38 INDEX APPENDICES LISTOFTABLES Page Table 1-L Summaryofdisposal operations overthe Morris Coveborrowpit duringthe 1999-2000disposal season 2 Table2-1. MorrisCoveborrowpitREMOTS® SamplingLocations 7 Table 3-1. REMOTS® SUMMARYTABLEFORTHEMORRIS COVE BORROW PIT 14 Table 3-2. REMOTS® SummaryTablefortheNewHavenHarborReferenceArea 15