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MarineMammalObserverReport

Project:MaintenanceDredging,DublinPort

MarineMammalObserversReportforDredgingandDumpingActivity

June-July2016

Client:DublinPortCompany

ForeshoreLicense:AKC/2016/00262

DumpingatSeaPermit:S0004-01

EcologicalConsultants:IWDG

MarineMammalObservers:PaddyO’Dwyer,EndaMcKeogh,

ClodaghRussell,LoraineGrant,StephanieLevesque

IrishWhaleandDolphinGroup

MerchantsQuay,Kilrush,CoClare,Ireland

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ContentsExecutiveSummary..................................................................................................................3

DredgingReport.......................................................................................................................5

Dateandlocation.................................................................................................................5

MMOdetails.........................................................................................................................5

Otherplatform/vesselinvolvedintheoperation/activity...................................................6

Co-ordinatesfortheareasofoperationsmonitoredbyMMO............................................7

Observationplatform...........................................................................................................7

Detailsofsound-producingoperations................................................................................9

Detailsofmonitoringwatches.............................................................................................9

Detailsofallmarinemammalsightingsrecordedduringmonitoringwatches.................12

Detailsofallmarinemammalsightingsrecordedoutsidemonitoringwatches(e.g.,incidentalobservations),includingrecordsfromadditionalpersonnelonboard.............14

Detailsofanyproblemsencounteredduringmarinemammalmonitoring,start-upprocedures,ramp-up(soft-start)proceduresorduringfullscaleoperation/activity........14

Conclusions............................................................................................................................14

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ExecutiveSummaryThe IrishWhale and Dolphin Group (IWDG)were contracted by Dublin Port Company to

provide experiencedMarineMammalObserver’s formaintenance dredging and dumping

operationsinDublinBay,CountyDublin.Dredgingoperationstookplaceover42daysfrom

20thJuneto31stJuly2016.WherepossibleanMMOcarriedoutaminimum30minutesvisual

monitoring of a 500m exclusion zone for the presence of marine mammals before

commencementofactivities.

Therewere134sightingsofmarinemammalsduringthemaintenancedredgingcampaign.

Greyseal(Halichoerusgrypus)wasthemostcommonlyrecordedspecieswith76sightings

(57%)followedbyharbourporpoise(Phocoenaphocoena)with56sightings(42%).Therewas

onesightingofaharbourseal(Phocavitulina)andonesightingrecordedasunidentifiedseal

asspeciesidentificationwasnotpossible.Ofthe134sightingsrecorded,61%wererecorded

duringthewatchpriortothecommencementofdredginganddumpingoperations.

Atotalofthreedelaystooperationswereinstigatedbytheobservers,twoofwhichrelated

tomarinemammalsbeingpresent in themitigation zonewhile theotherwasdue to sea

conditionsnotbeingsuitableforconductingapre-watch.Inbothofthedelaysduetomarine

mammalbeingpresentinthemitigationzone,operationswereallowedtocommenceonce

theanimalhadleftthemitigationzone.

Therewere606pre-watchescarriedoutbyMMO’sduringtheproject,with54instancesof

operations commencing inpoorweather conditions (sea state>4) and the remaining552

occurring in suitable conditions (sea state <4). Additionally, there were 249 instances of

operationsstartingatnight.ItisgenerallyrecognizedthattheNPWSguidelinesneedtobe

reviewed in relation to dredging operations. The continuous nature of dredging activities

requiresoperationduringhoursofdarkness.Monitoringduringnighttimeoperationsusing

hydrophonescansupportmitigationmeasures.

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In the opinion of IWDG Consulting, it is highly unlikely that the dredging and dumping

activitieshadanysignificantimpactonmarinemammalsintheareaandatworstmayhave

causedtemporarydisplacementofsomeindividuals.

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DredgingReportDateandlocationImplementationofmarinemammalmitigationmeasurestookplaceon42daysfrom20thJune

to 31st July 2016 at Dublin Port in Dublin Bay, County Dublin to support a maintenance

dredgingcampaignbeingcarriedoutbyDublinPortCompany.Thedredgingareasincluded

numerous berths in the port downstream of Alexandra BasinWest, and inner and outer

navigationapproachchannels.ThedumpsitewaslocatedatBurfordbankapproximately5km

SouthofHowthhead.Thedumpsiteisapproximately12kmfromthewesternmostdredge

siteand4.5kmfortheeasternmostdredgesite.(SeeFigure1below.)

Figure1.Theareastobedredgedandspoilgroundsforthemaintenancedredgecampaign

(redboundarylines).

MMOdetailsThe marine mammal observer’s (MMO) who monitored the implementation of NPWS

guidelinesduringthedredginganddumpingwerePaddyO’Dwyer,EndaMcKeogh,Clodagh

Russell,LoraineGrantandStephanieLevesquewhoareallexperiencedJNCCtrainedmarine

mammal observers (See CV’s in Appendix I). Paddy O’Dwyer and Enda McKeogh were

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stationedonthedredgevesselthroughoutthecampaignwhiletheotherMMOsusedwere

stationedonlandatthedredgesite.

Otherplatform/vesselinvolvedintheoperation/activityThe Boskalis vesselMV Freewaywas contracted for the dredging operations. It is a 92m

trailingsuctionhopperdredgerwithacapacityof4,500m3(seeFigure2below).TheFreeway

canreleaseitsloadinapproximately30-40secondsfollowedbyafurtherfewminutestowash

outtheholdingtankandtofullyclosethedoors.

TheFreewaywassupportedbyvesselsoperatingploughsandbackhoestodistributeand

accesssedimentsfordredging.Theseoperatedcontinuouslywithintheportarea.Asurvey

vesselalsosupportedthedredgingprogrammeandoperatedthroughoutthearea.

Figure2.Trailingsuctionhopperdredger;MVFreeway

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Co-ordinatesfortheareasofoperationsmonitoredbyMMO

Table1.Co-ordinatesforareasofoperation

NorthQuayExtension FerryPort53'20.79' N 06'13.63' W 53'20.68' N 06'12.18' W53'20.78' N 06'13.63' W 53'20.70' N 06'12.19' W53'20.74' N 06'12.98' W 53'20.71' N 06'12.02' W53'20.73' N 06'12.98' W 53'20.88' N 06'12.00' W

SouthQuays 53'20.89' N 06'11.92' W53'20.64' N 06'12.89' W 53'20.80' N 06'11.87' W53'20.63' N 06'12.90' W 53'20.69' N 06'11.88' W53'20.55' N 06'11.87' W 53'20.71' N 06'11.57' W53'20.54' N 06'11.87' W 53'20.67' N 06'11.40' W

OilBerths 53'20.70' N 06'11.45' W53'20.69' N 06'12.45' W 53'20.75' N 06'11.49' W53'20.82' N 06'12.43' W 53'20.86' N 06'11.49' W53'20.85' N 06'12.39' W 53'20.88' N 06'11.58' W53'20.84' N 06'12.25' W Dumpingsite53'20.80' N 06'12.23' W 53'20.07' N 06'03.00' W53'20.69' N 06'12.24' W 53'20.07' N 06'01.82' W53'20.68' N 06'12.18' W 53'19.17' N 06'01.82' W

AlexandraBasinEast 53'19.17' N 06'02.71' W53'20.72' N 06'12.75' W 53'19.38' N 06'03.00' W53'20.69' N 06'12.45' W RiverAreaB53'20.82' N 06'12.43' W 53'20.65' N 06'09.00' W53'20.83' N 06'12.74' W 53'20.57' N 06'09.05' W53'20.72' N 06'12.62' W 53'20.72' N 06'12.75' W53'20.73' N 06'12.74' W 53'20.64' N 06'12.85' W

ObservationplatformAtotalofthreeMMO’swererequiredsimultaneouslytoimplementthemitigationguidelines

forthisproject.TwoMMO’sconductedwatchesfromthebridgeofthesourcevesselwhich

providedaviewingheightofapproximately7.5metersabovesealevelbutvariedsomewhat

dependingonwhetherthehopperisfullorempty.Landbasedobservationswerecarriedout

fromCoalpier(53012.10,-06005.35) inDublinPortandprovidedexcellentviewsintothe

variousquaysintheport(SeeFigure3below)whichweretobedredged.

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Figure3.Locationoflandbasedobserver(yellowpin).

The vessel based observers conducted watches from dawn to dusk while the land based

observerconductedwatches from08:30 to17:30.The landbasedobserverconductedpre-

watches for dredging in the harbour and inner channel areas only while the vessel based

observersmonitoredtheseareasinadditiontotheotherdredgesitesnotvisibletotheland

basedobserverandspoilgrounds.Thevesselbasedobserversconductedwatchesusing7*50

binocularswhilethelandbasedmonitoringwasconductedusinganOpticron30-70xtelescope.

Alldatawasrecordedontodataformsforcoastal/marineworkswhichweresourcedfromthe

National Parks andWildlife Services’ document; “Guidance toManage the Risk toMarine

Mammals fromManMade Sound Sources in IrishWaters” and later entered on an excel

spreadsheet.

Pre-startwatcheswere conductedduring transit between thedredgeanddump sites. This

resultedinmostofthepre-startwatchesfordumpingbeingapproximately20minuteslong

but reduced thedurationof theprojectbyover threedaysand so limited theexposureof

marinemammalsintheareatotheoperations.ThepresenceofathirdobserverbasedonCoal

pierintheharbourallowedforthemajorityofpre-watchesintheharbourandinnerchannel

tobe>30minutes’duration.

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However, it should be noted, as described above, that the dredging operations were

continuousinthesensethatthedredgerandsupportvesselsoperatedcontinuouslybetween

dredging and dump sites. Any pauses in the campaign due to bunkering or repairs were

preceded by 30minute pre-start watches. It was decided that all transits of the dredger

betweendredgesitesanddumpareawouldbeprecededbypre-startMMOwatches inthe

interest of best practice. Underwater noise monitoring undertaken during this dredging

campaignhasconfirmedthatnoiselevelsgeneratedbydredgingwerebelowthedisturbance

levelsformarinemammalsandfishat213mfromsource.Italsoconfirmedthatnoiselevels

generated by dredge spoil dumping operations, although slightly above the response

thresholds for harbour porpoise at 90m from source, are below the general behavioural

thresholdforharbourporpoiseatthisdistance.Itisclearthereforethattheimplementation

ofthe500mexclusionzoneduringthiscampaignisaneffectivemitigationmeasuretoprotect

marinemammals.

Detailsofsound-producingoperationsTherewasatotalof429dredgingoperationsand429dumpingoperationsduringtheproject.

Operationsran24hoursperdayand7daysaweekexceptduringbunkering/resupplyand

duringunexpectedbreakdowns.Table2belowprovidesasummaryofoperationsbutfull

detailscanbefoundinAppendixII.

Table2.Summaryofsoundproducingoperationsduringtheproject

Description Number Duration(hh:mm)Totaloperations 858 486:37:00

Totaldumpingactivities 429 60:18:00Totaldredgingactivities 429 426:19:00

DetailsofmonitoringwatchesAtotalof780hoursand34minutesofmonitoringeffortwascompletedduringtheproject.Of

this, transiting between the dump and dredge sites accounted for 54%, dredging activities

accountedfor40.6%anddumpingactivitiesaccountedfor5.4%(seeFigure4below).Atotal

of606pre-startmonitoringwatcheswerecarriedout (304of thesewereprior todredging

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operationsand302werepriortodumpingoperations).Fulldetailsofmonitoringeffortcarried

outduringthisprojectcanbefoundinAppendixIII.

Figure4.Percentageofmonitoringeffortconductedduringthedifferentoperationsstatus

Sightingsconditionsduringtheprojectweregenerallygoodbutperiodsofpoorweatherdid

occur.WindsrecordedduringobservationswerepredominantlyWestorSouth-westerly(see

Figure5below).

Figure5.Summaryofwinddirectionthroughoutobservations

41%

5%

54%

Operationstatusduringobservations

DREDGING

DUMPING

TRANSIT

051015202530

N

NE

E

SE

S

SW

W

NW

Winddirectionduringobservations

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Thevisibilitywashigh(>10km)forthemajorityofobservationsduringtheproject(96.5%).

Good visibility (5-10 km) accounted for 1.8% of observations, moderate visibility (1-5 km)

accountedfor1.3%andpoorvisibility(>1km)accountedfor0.4%ofobservations.SeeFigure

6below.

Figure6.Summaryofvisibilityduringtheproject.

Therewasnoswellforthemajorityofobservationsduringtheproject(82%ofobservations)

andlowswell(0-1m)for18%ofobservations.SeeFigure7below.

Figure7.Summaryofswellheightduringtheproject

0.4

1.3

1.8

96.5

Poor(>1km)

Moderate(1-5km)

Good(5-10km)

High(>10km)

VisibilityduringObservations

%

82%

18%

Swellheightduringobservations

Noswell 0-1m

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Seastatewasgoodforthemajorityofobservationsduringtheproject.Thevastmajorityof

observations(91%)werecarriedoutinaseastate<4while47%wascarriedoutinseastate

<2.Thehighestseastaterecordedwasseastate6andthisaccountedfor3%ofobservations.

SeeFigure8below.

Figure8.Summaryofseastateduringtheproject

Detailsofallmarinemammalsightingsrecordedduringmonitoringwatches.Therewere134sightingsofmarinemammalsondayswheredredginganddumpingactivities

tookplace.Theanimalswerewelldistributedwithsightingsoccurringatbothdumpanddredge

sitesaswellaswhiletransitingbetweenthese.Thegreysealwasthemostcommonlyrecorded

specieswith76sightings(57%)followedbyharbourporpoisewith56sightings(42%).There

wasonesightingofaharboursealandonesightingrecordedasunidentifiedsealasspecies

identification was not possible. The highest number of individuals recorded was harbour

porpoisewhichaccounted for approximately54%of the total numberof individualmarine

mammals sighted. Table 3 below is a summary of all sightings during the project but full

sightingsrecordscanbefoundinAppendixIV.

9%

38%

26%

18%

6%

3%

SeaStatesummaryduringproject

SS1 SS2 SS3 SS4 SS5 SS6

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Table3:Summaryofsightingsrecordedthroughouttheproject

Species Numberofsightings

Numberofindividuals Groupsize Adults Juveniles Calves

Greyseal 76 77 1-2 77 0 0Harbourporpoise 56 93 1-5 74 1 18Commonseal 1 1 1 1 0 0

Unidentifiedseal 1 1 1 1 0 0

Themajorityofharbourporpoisesightingswerewelldistributedthroughouttheoperational

areaoutsideoftheharbourwhileonlythreeharbourporpoisesightingsoccurredinsidethe

breakwaterwalls.Figure9belowshowsthedistributionofharbourporpoisesightingsduring

theproject.

Figure9.Thedistributionofharbourporpoisesightingsduringtheproject

Themajorityof seal sightingsoccurred inside thebreakwaterwalls.Allbut twoof the seal

sightings recordedwereofgreyseals. It is likely thatmanyof theseal sightings inside the

breakwater are duplicate sightings of the same animal at different times. Figure 10 below

showsthedistributionofsealsightingsduringtheproject.

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Figure10.Thedistributionofsealsightingsduringtheproject.Greenpointsrepresentgrey

seals,whitepointrepresentsacommonsealandthepurplepointrepresentsunidentified

seals.

Detailsofallmarinemammalsightingsrecordedoutsidemonitoringwatches(e.g.,incidentalobservations),includingrecordsfromadditionalpersonnelonboard.Therewasoneincidentalreportwhereasighting(129)wasrecordedbyalandbasedobserver

aftertheyhadcompletedtheirwatchbutremainedinthearea.

Table4:Summaryofincidentalobservations

Species Groupsize Adults Juveniles CalvesGreyseal 1 1 0 0

Detailsofanyproblemsencounteredduringmarinemammalmonitoring,start-upprocedures,ramp-up(soft-start)proceduresorduringfullscaleoperation/activity.Therewerenoproblemsencountered.

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ConclusionsA pragmatic best practice approach was taken towards implementing the mitigation

measures required for this project. Although dredging and associated activities were

continuousduringoperation,watcheswereundertakenduringdredgertransittoandfrom

the dump site. The transit timemeant watches were generally of 20 minutes’ duration.

Comparedtotherecommended30minutepre-watch,thisresultedinshorteningtheduration

of the project and exposure of marine mammals by over three days (75hrs 37mins). By

allowingoperations to commenceonce an animal had left themitigation zone insteadof

waitingafurther30minutes,thepotentialfordelayswerereducedandoveralldisturbance

totheanimalsminimised.

In the opinion of IWDG Consulting, it is highly unlikely that the dredging and dumping

activitieshadasignificant impactonmarinemammals in theareaandatworstmayhave

causedtemporarydisplacementofsomeindividuals.