peer review report 2 on groundwater derived nutrient and trace element transport to a nearshore kona coral ecosystem experimental mixing model results

40 Peer Review Report / Journal of Hydrology: Regional Studies 9 2017 39–40helpfultobeabletocomparethevariationinnutrientandmetalconcentrationsalongrealsalinitygradientsintheharbors toth

Journal of Hydrology: Regional Studies 9 (2017) 39–40

Studies

j o u r n a l h o m e p a g e :w w w e l s e v i e r c o m / l o c a t e / e j r h

Peer review report 2 on “Groundwater-derived Nutrient and Trace

Element Transport to a Nearshore Kona Coral Ecosystem:

Experimental Mixing Model Results”

Original Submission

Recommendation

DOI of the original article: http://dx.doi.org/10.1016/j.ejrh.2015.12.058

http://dx.doi.org/10.1016/j.ejrh.2016.11.028

40 Peer Review Report / Journal of Hydrology: Regional Studies 9 (2017) 39–40

helpfultobeabletocomparethevariationinnutrientandmetalconcentrationsalongrealsalinitygradientsintheharbors

tothoseyouobservedinyourlabmixingexperiments.Ifthepatternsaresimilar(especiallywiththeHH2monitorwell mixingexperiment),itwouldsupportthevalidityofyourapproach.Iftheyaredifferent,thenyouwouldneedtoexplore whatisbehindthatdifference

3)Theacidificationstepinthephosphatemixingexperimentisnotexplainedsufficiently.Presumablytheacidificationis supposedtorepresentaprocessorconditionthatcouldoccureitherinthesubterraneanestuaryoraftergroundwater dischargesintothecoastalocean,butIreadthearticletwiceanddidnotgetasenseofwhatthatprocessorconditionis supposedtobe.Theacidificationstepisnotmentionedatallinthemethods,andimportantinformation,suchaswhat

pHthesampleswereacidifiedtoandwhatacidwasusedtoaccomplishthis,areleftout

4)ThereisnoexplanationofwhytheparticularmetalsBa,Mo,UandVweremeasuredinthisexperiment.Thisneedstobe clearlyexplained

5)Thenon-conservativemixingofphosphateinthemixingexperimentsisadramaticandinterestingresult.However,the explanationforitisnotcompletelyclear.Itseemsliketheauthorsaresayingthatachangeinsurfacecomplexation explainsthenon-conservativereleaseofphosphateatintermediatesalinities.Butwhatsurfacesarethese?Surfacesof suspendedparticulatematter/colloids?Ofthebottlesintheexperiment?Sedimentorrocksurfaceswithintheaquifer? 6)Ialsothinktheintroductionistoogeneralandneedstocontainmorespecificinformationrelevanttotheexperimentthat wasconducted.Makeitreallyclearwhatpartsofthisstudy/experimentbuildontheresultsofpriorwork(e.g.thefairly abundantliteratureabouthowSGDsupplieslargenutrientsubsidiestocoastalwatersontheKonaCoast)andwhich partsarenew.Haveothersinvestigatedtheroleofcolloidsinmetal/nutrientloadingbySGDbefore?

Minorissues

1)Lines66-71,“Withhighpermeability KalokoHonokohauNHP ¨Thisisapoorlystructured,run-onsentence.Pleaserevise 2)Line115:Putacommabetween“downward”and“contributing”

3)Lines118-119:“freshwaterlens”doesnotneedtobehyphenated

4)Line165:Whywastheminimum2hours?

5)Line182:Change“Totaldissolvednitrogen(TDN)bymeasuredby”to“Totaldissolvednitrogen(TDN)wasmeasured by”

6)Lines200-201:“Therelationbetweensalinityandtemperature(Fig.2a)issemi-conservative”.Idon’tknowifitmakes sensetotalkabouttemperaturebeingconservative.Maybeitwouldbebettertosaythatbothincreaseinasteadyand generallylinearfashionwithdistancefromtheharborterminus,orsomethingsimilar

7)Lines223-224:“Silicicacidconcentrationsdominatedthetotalnutrientinput”.Idon’tthinkitmakessensetotalkabout thetotalnutrientinput,becausethesumisnotreallyrelevant,andphytoplankton/algaehavedifferentrequirements foreachnutrient

8)Line229:“inorganicN”doesnotneedahyphen

9)Line237:Change“greaterthanHHmonitorwellno.endmember”to“greaterthantheHHmonitorwellno.2 endmem-ber”

10)Lines243-244:Changethissentencesothatitisclearyouaretalkingabouttheresultsofpreviouswork(whichitseems likeyouare,basedonthecitations)ratherthantheresultsofyourstudy

11)Lines252-253:Change“canbefocusedaspoint-sourcedischargesratherthandiffusegroundwaterflow”to“canoccur

aspoint-sourcedischargesinadditiontomorediffusegroundwaterflow”

12)Lines251-255:Ithinkthatthisstatementwouldbejustastruefordiffusegroundwaterseepageasfordistinct ground-watersprings

13)Lines256-257:Change“areareflection”to“arelikelyareflection”

14)Lines259-261:Thisinformationshouldbeintheintroduction

15)Changelines271-272to:“AlthoughtheWWTFappearedtobeapointsourceofnutrients,thatwasnottrueoftrace elements”orsomethingsimilar

16)Lines306-307:“havebeendemonstratedinbothlabandfieldstudies”.Pleasecitelabandfieldstudies(notjustone study)

17)Lines321-322:“TheeffectofpHonadsorptionofphosphatehasbeenpreviouslyobservedinseawaterforgoethite (FeO(OH))¨.Explainthismore.Isthegoethiteinsedimentsoraquifersubstrate,orisitdissolvedinthewater?

18)Lines334-335:“ThispatternwasexplainedbyarapiddropinSPMatasalinityof15”.Isthisinthelabexperiment,or

intheharbortransect?WhatisthemechanismforthedropinSPM?

19)Lines336-339:Idon’treallyunderstandwhatyouaresayinghere.WasSPMpresent?Youcan’tinvokeitasanexplanation

ifitwasn’tthere

20)Fig.4seemstoreplicateinformationthatisalreadyinTable4,andIthinkitshouldberemoved

21)Figures6and8andthebottomhalfofFig.5seemtocontainmostofthesameinformation.Canyoumergetheminto onefigureexplainingnon-conservativemixingofphosphate?

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