Trace metals associated with seston collected from Spencer Gulf, South Australia, near a lead smelter: Spatial distribution, temporal variability and uptake by bivalves

13 Pages·2003·5.1 MB·English

by  K E Ross

It(tit\(titi<}ns<tttth'l<<'v<tf TtuTctyoft- fl"W- !2il(Mk !27i I). .k-M5
TRACE METALSASSOCIATED\VITH SESTON COLLECTED FROM
SPENCER GULF, SOU III AUSTRALIA, NEARA LEAD SMELTER; SPATIAL
DISTRIBUTION,TEMPORALVARIABII V AND UPTAKE BY BIVALVES
1 1
by KirSTLN E. Ross Josr.pn R. Binwt-i Via mm Wii mams cy John Roland
, I , i
Summary
Rforsosm,SKpen1c.e.rHdhulmli.1S1o.utIhRA.usWtiraili1ai,winse.w\\a l&e:adBrsjUmfeylll.*e,rJsp[a2lfMm)!2jd.iTsitntifbiuc!imoent.altsemapsosrocailatvejd+mwbiilliblv-.casntdontcidptln-Kccicbdy
biMvacllvaels.inTpruatns.IfAw*mSpuoemiS-.soUuifrielcI2d7i(scIh).ar3gMes?<ins3ul1tsM.iiny.c2o0n0c.eVntrations ill (he receiving areas lhai vary m bvMfi
spaceandlime. Inorder Idattestthespatialdistributionaniltemporal variabilityofmetalsintheUpperSpanctir
(mil as a fesull o( metal inpul born a loot! smeller, scsion was eoilcclcd OVfil six week periods at eight sites,
around Ihcgulf A(OlffJ l>I 23collodions fromtheehjhtscsionsamplingsilosWas i»atic. I.e\elsofmetals in the
titi*hin were elevated at Ihc Ann sties closest [p I-"»rsi Crock (the smelter diluent disclukgc creek) Sertoli
eolleeled fiom sttQ Wii (the site closed to the -ancllcr) contained ihc highest levels WTvll measured metals.
sIineeiav;se-otensdalUFl'mirnln*lblu2ijcnfn>EcWfvlbtnslcs>sc5is3oi0nonfriamg/neftgcaeld41l,fe2rvoemls3LJSwf7ai3sf|lffJio/^jugSn.dlSo6a»lSlflaflilflf3fM1itl1tta&flcl1xgwc/hegipallneWdloe2.v4e1Tlsheof9e2\/1lnc.ijuitgodg.f,'CFhmcis\saspmceicalsiMo\nenalyl.aliAn(fhslilsuiesonicnlegc
was evaluated using lime scries analyses' and (he influence incorporated to deici'iinne ovcfsll Ironds. Seasonal
\nnaiion accounts forone third lo hall'the variation in deposition annually, Most wiles exhibited highermetal
levels in wirnei. ennesponding with tins decreased seston deposition in (hat season,and eonscscly. increased
mclal concentration* m summer,corresponding vtjlji lusherdeposition rules.There was no bignificant change
ftVCT lime in deposiiion ralesal any ofIhcMtW CKGCpl W(». ibr which ihercwasa decrease in mial dL-pttsiiion
O-Vvi 'he mnnihtrniltperititL Must site> >litiweil siHiMically significant changes in scsion inelal levelsoverihc
diree yearsol'lliestudy Thesitecloses! loihccll^ucnl ouflali (Woi was theonlysite lltalshoweda^ignilkunl
increase in metal eoneeniralions over llie moiulortu;-! period. IIns "andy mdtenies thai fret|»ienl- rcijular
inoniiiiriniiofseMtininelalsalhuvs\aiiotionarising fromseasonaldifferenceslobelaKen intouecount.allowing
teinporal changes lt» heelucidated To evaluate bioavailability ulmetals assoeutied with seston in the Uppur
Speneei (tulfdbt which Iherewerelargequanlilieso\ nictol dutai e\pcrimcniswerei.ondncted using <fHilnha
|/Vrfcn oHhi Talc) (siiinnicrl and seallops jud mussels [<\f\tihn L-dult.s Linnaeus) laulumu exposure). Vlussefs
werealso placed al theseslon samplingsilcclosest to theeffluent oulfaH and removed>U iiUen';d.sovet Uiesiv
week samplint'periodin aiiiuiiin lodeicrnnne ihc rateofmeiul uptake lissueswere analysed l"i levelsofPb,
Id.Lu.7nand Mn.andihclevelsal caehsjli:comparedwilb lhai inIhcsesluii \strongrelaiionvhipwasRnunl
between the levels ol'Pb and /n in seston andseaJlop Pband /n uptake,whi-ivas (u and t d kwels in seston
,bowedPUleUitMinslup wilh those inscalloptissues I eadand Xn inmussel tissuewere related in Chand /n ill
.seston.andiheicwerealsoweakerrclalionslopslvi\ceeuthelevelsnlTd^nd("uinthemusseltissueandsesion.
alihough relauonships wilb these metals Mere net delected in ihc -;eallops, The temporal aceuimiiaiton ^kid>
iudieated that nuhsels were regulating some meuds. uiili /it and Mn levels initially iiKieasing Ihen levelling
olf. t"atlmium lcvel> were high in the scallops <_olleeled from the reference site, ^\m\ showed no significant
oiercaseon relrieval afiei si\ weeks nearihc,smeher Cadmium in 'he mussels inereasce! significantly overthe
six week esitosiirc period, Copper,levels were ;i|so high in the seallops luim llaidwieke Bay, ami decreased
siyinfieJiul\ jlkrsix weeks in summer.< oppcrk\eis rcinainedslauc forholb musselsand scallopsmJiuiumn.
Keiiheridn»>rCushoweda relationship hetweer die levels inscsion andscallops in eitherexposure,
iluring louj sestnn colleelioils the lolal organic carbon (VOC) eoiileni and llie particle M/e distribulion of
sestoncolleckdilltineachofihcsiteswasdclernuned.Sui-pitsinglv norelationshipswere foundbetweenctlhei
T(K content of pniticlc si/e ofscsion and nktal eoneeniralions in the bivalves siu/gcsiing lhai the muior
uilluoneem lussuemclal level is ihc total concent ationofthe metalsin the seston. Tlwse results;ireconfirmed
ip:o1ieulai-lv in theeuseol"Pband/n)hy ilk ivkiltoivdups helweellsest*)tlmetals and bivalve tissue le\ek
Kivwonn^. tracetnelals, scsion, Spcncci (Jult setillop,mussel, Pi\imallm. Uviilt.yvJuli\.
Introduciion
l.t)caliscd Itace melul pollulkm fruin iiitltisttiul Of
WNial-dlleifeHal,l,ml3I2iS>«lk-I.Ak>M'>>u..UMt''l.l-c-ficItfSKuflaSio-,n\,A,:lxwM^.U7l,Ml.W-d'^\l)V$.A2_1.*(,1 mnuiimjioerip'a'.lisswuaessteslabcais.ngfjeenlliiedcnlAitliisclirlalaisati(rtiCmoalrilnitee
JnIuVjiniali7llhili.lL^7-uHivH.sdu!M.iyH\HH>.lf«iiLi*u\. Okfjtltunia Sian- t nivriMl'.. mvM nCI eansvsoicrtoanli,endeiniwi-li.ibZnnvnvui.e!rL.^L>5pu>.rlStiennekixi*l.omemta,at.lte„r.le-va„enldsi
School "i RwrwmieUiiiWlt WAUffnbw .a»a iiiunmii^d Neuro. soditttont can vtffy t)Vci lime, deiennmine lift? cxienl
St1tn1(Irht.coovrls$ioAl^-oVf-l1'iItSWlo3huen.uhiUAeuvs,UiUnho,eiAsi(kllv1(o(fk:So^u\ll«i*A*tr\li.ilii. |Wil**0Il i1(ifnd„e.TlMLaViidnitcntgalofeiibierispcab'm,eundlexriecqr'unir*>e!scinmoutimmm.fallVi,on;,m
34 K. F. ROSS,J. R. BIDWL1_L. M. WILLIAMS &J. BOLAND
but also df the degree of temporal variability
associated with metal levels in the various phases.
The aim of this study was to determine 1he spatial
distribution and temporal trends in seslon metal
levels in the Spencer Gulf, an area that receives an
effluent withelevated metal concentrations from one
of the world's largest lead//inc smelters. Seston for
the purposes o! this study is defined as the living Of
dead, inorganic and organic particulate matter
temporally suspended in the watercolumn (i.e. thai
proportion that eventually settles into a collection
tube). As an extension ofthe studies of seslon metal
levels, uptake <_)f metals by organisms feeding on
.seslon was assessed. Molluscs are commonly used
biomonitors (Rainbow 1995), because they arc filter
feeders, tolerate a range of contaminants and are r^l>aUilomclivs,
widely distributed (George 1980; Morseeral. 1993:
Connel et ai 1999). Experiments were conducted
using scallops {Pertcn alba Tale) and mussels MytihtsI'tluliscollectionsite
<A/\7Hits edutis Linnaeus) translocated from (KangarooIsland)
reference sites and placed at the seslon collection
'PnrlPFrtaKttfm
Fig. I- The.siudv area
7 S
SI SION YtlTAI SAND HIVAIAI'S IN Hit; SPINCLKUULl -
sites. Pettenalhti are indigenous10thearea whereus Tvuu I. Sin-Ca-tmliiutii'sjot SctittnMiniplwxm'hs.
A/, i'dulis is a oiMiHi|Hiliiun species Fuli&fclc ft>I Sesionsamplingaire Siteco-ordinates
drawing beiween-sile comparisons (Rainbow 1^95). 51 335 1V7.^S2' S 137° 54.2('8' f
52 *3° 05.605' S 37°5S.724' r
oG7pfutelIrrlfaks-thvis\homhneSlsottiiuenrtrachteistAhulesotarInSa9el3di)asi.\\(PhPrioogr.ctesP1si)riinaegnodmnahitanhsleySbpPeebenneacnitdn \sSvI4i a_vviycD 0Ba33..m9M14e*'' sSS I1ii33P7?°! *5s1x..m1t3uf©nt''j fII
/.n, in addition lo lesser quantises ofother mcuiN W3 3.V: 1)0,641' S 137" 4<->.4-W' I
and alloys, the facility has been D source of mclal Wo 33" 08,034' \}T57.728' L
input into the gulf formore than one hundred yems. \V 33" 04,422' S 137' 4K In7 I
The extent and impact ofelevated metal levels was
assessed througha series ofstudiesconducted in the mm
35
lale 1970s and'early 1980s (Ward <>t ul. 1982: 1984:
Ward tV Young I9~S4; Ward, cf ul. I9K4: Ward &
Mulchings I$96). In addition lo some ofthe highest
ever reported levels of metals in sediments (5000
lig/g Pb. 1M)00 yaffg /n and 260 ue/e I"di. these
studies also demonstrated that marine plants and
animals (ftij* example. I'ns'uloniu uustrulis, Pimm
hiittfur, Pt'nufu\ tutisttltutus. Portunus fkj/>ii>t< t\)
neat the smelter had accumulated melals in their
tissues (Ward et ul 19X2). Ecological effects
included the absence of some species from
eommuuilies in heavily contaminated sites and llic
presence ofsome species that appeared particularly
resistant to high metal levels (Ward et ui 1982).
1lisiorieaHy, waste metals from the Poll Pirie
smellerwere derived Irorn slack emissions and dusl
blown from the site, release of liquid effluent Mid 400 mm
loss ofmetal oresandconcentratesduring loadingof
ship-, (Wardft ui I9K2K Most ofthesesources hftVC
been minimised 01 eliminated as facilities were
upgraded and more rigorous environmental policies
adopted. HtJWTJVCT. the wastewatereffluent continues
to bea significantsourceoftrace metals,notably Pb.
Ai,Ul.Oil and Mil(Ward ctul. ll>84i.Currently,the
average cfTlucnl discharge levels are around KOJHK)
m doy. Ihe effluent is released into (I rapidly
Mowing small tidal creek (first Creek) thai leads to
the open waiers of the gnlf hi their studies of die
smelter receiving system. Ward t-7 ul. (I9#4) cement weight
tmienassuprheadse(rabceecmaeuUsiel alCVCl(a.Ho^efa p-r-coMpoonr.tiTohneyolclitohuec Klfc, 2 SeMim Saiflfi|cT
organisms wtthin thissystemarcfilter feeders(Ward
eelxaulm,inI9e,S4m),etTahleloebvjeelcstivienosfetshieonstubdeycawuassetoofagafliinc asraem.)pl(eIresi'wwte.rsoenmIa9dSe3)ol("TPabVlCe tI;ubFiint:g (/M<,/ Ih>e5 smesmion\
ecological significance ofthis phase. •400 mm bang; total \olume - 3X5 ml), with inserted
baffles lo prevent re-suspension ofcollected sesion
Muterials and Methods (lourlubes\n:rsite)."Ihe samplerswereattached toa
concrete block such that ihe opening of the lubinu
Sampling facing up was approximately one metiv above the
Sesion samplers (I ig_ 2) were placed ai eight sites svdimeni (Ward rt ah 1L»S4) Iwo blloV$ weie
(SI S2. S3. S4. Wl. YV3. Wo.\V7) (Fig. I». The W- attached to thesamplerslo makethe sitevisible. The
sites approximatethose used in thestudy by Ward e/ collected sesion was recovered as close to six week
ul (1982) The S-sites were chosen to follow iulenals as weather eondi!ii>ns allowed- Samples
pu-\.iiling currents and tidal movements within die were retrieved bv polling them froilfl the water in a
Hi K L ROSS.J K UIIUVILL.M WILUAMK&J HOI VNP
manner lo nnliimi-c disturbance Of the collcctctl Hai'dwicke Hay on die Yorke Peninsula Of South
^esiom Incli lube was capped and the samplers Australia, and mussels from Kangaroo Island
returned to the laboratory. On retrieval. Mew lubes approximately 15 km from die South Australian
were placed in (he sampling rack to initiate ilie next mainland. These siles had previously been reported
collection, twenty three CollCctHlJU ai the ei.'jh' to have low metal eoneentiations (/aim IWV. Ward
seston NUinpline sites were made between July I***)? (/ ill. 19X4), Both specieswere held in flow through
and November 2000, tanks for several days for depuration prior to
translocation. Thirty scallops (20 in summei and
Sexion dtgtiStilm utttitnulIy.sM 10 in autumn) <wm\ nine mussels were retamed
Seston collected Iron) each tube was filtered for digestion to establish initial trace metal
W
through pre-weiyhcd titters (Whatman1 25jmi concentrations (designated as reference concen-
afnodllosewsetdonbydr1i1e4d5toioancIodnlsetrasntMiwle1i1gphotret i.70diDe(')l_llTiheres atrnadtisocnsa)l.loMpusswseerles p(pllaacceeddinfirpsltasiltlicmecsahgeosiaatntuaechbeadys11)1
first 13 sets ol samples were digested with 211 inl the seston samplersat each seston sampling >ite(l iu
?W» UNO ( \tudar1 i and 10 ml 70",, llt/lo I) and left in place for sis weeks. Scallops were
(Analai l lave millilitrcs 37% JKU (Amilar') was placedat all sites in ihcsummerexposureandatsites
added to the iK.|iiCMiis fraction remaining from the S3 S3. S4, Wl and W7 m the autumn exposure.
digestion and was made up lo 50ml -with Milli RO' MUSSelS WfcRS placed at all sites except W4 m the
water, The otherten setsofsamples weredigested m autumn.
H Oj ami UNO followed by IICI (thechangedue to Ai the c\k\ of the Held exposure, scallops and
a titanic m policy ofregarding (he use ofHCIO, ai mussels were returned lo the laboratory and each
our research institution) and made to 50 ml with whole Nxly dried tO aconstant weight ai 70"C prior
Mitli l«> Tiller paper, fluid blanks and rivw lo digestion in HNO, and HCIO, (Altaian Tissue •
sediment relerenee standard (Standard Reference wete analysed tor levels ^\' Ph, CM, (V /n and Mn
Material ftjM^ Washington, DC) controls were LttiiiQE atomic absorption spcctioseopy, A bioloeital
Hied, Samples weic analysed tor metal standard, mussel tissue itiBVV OK571 tobtain.:d lioni
concentrations usine,atomic absorption spectroscopy ihc Nalioiial KeseaiclU eiilie fol Citified Kefeivmv
(Varian ). The difference in results for the two Maici'.alv IC'RM). iCiraham H Jackson Ply I,id,
digestion techniques i\n\nd in the sediment standard VicioiKi.Ausiralun. wasdigested and aualvsed in die
were u-cd to "correct* hitler samples for differences same mannei as the samples.
m metal recovery arising from the different
dieesliolls. /im/ioruiiffhtkc
Mussels were placed ;tl Wn (the seston sampling
site closest to the elllucnt outfall) and 5 lo 6
I>uiing fourof the collections in autumn, die jplftJ individual . u-mo\ed foi analysison davs 3, 7. 14, 2K
OrjUirik* carbon (TOO eonlenl and the panicle si/c aitd 42 over the si* week e\posme (iciiod in automu
diMribulion ol sesion collected fromeach o\ the sites iodetermine the rateol metal uptake. Only M, atiilis
were determined. The panicle size fractions above was u^cl\ Ioi this study smee ilu- loeauon was both
below 75 nm were determined by wet sieving shallow (and therefore subteei u* iiipnJ lemperaiuic
.mo subsequent dryiivj Hi IODIC tor .?I h. T.rjti fluetnaiiousi and had hieh levels of suspended
| .it im>m below 75 (On wa- further characterised ,'>Iid .
ihiii^ a Laser MasteiMA-f (Maiwin Instruments
I nlf All fraetions (above63 prn, 63-4 inn and tltose Sitiiisticaiutiafvso
(bheelolwou4dpsmediiLmireeiur.epoTrOteCd awsasa pdeertceernmtinderdy wuvsim<;ehitohef seIansiotniaall emvlalluueantcioenonofbtohteh dsaetsatonsetdsepoisnidtiicoantedanda
modified Mcbius procedure described by Nelson & metal concentrations at mosi sites, lime series
SM.mmns I9N2»_ analyses werethereforeconducted oneach meial and
(
deposition dataset by re-ordering thednia by limeol
IS i Lin dba \tnJ Vlytiltis ctlulissttutios year, tra-speeiivc ofyearcollet led. COsftjc' ^"ivls
two SepnraJc exposure studies were undertaken. In
il.e Insi (summer exposure: WUffH 4/1/991 / (y x aoslini r -^b)
<ilhn -Acre die only organisms used. In the second
i.iuiinno exposure' 6/4/\>'> 1<X 5,,W). scallops and wheie. / meari metal coneenttation overmthe
W iJbti\ were used and additional mussels were samplint; period at each she. a and b are fie«|m >
i . \*l n iln- filft closest to the effluent outfall and and tna;^nilude variables. T 365 days, and l = day
collected at interval-, to assess temporal uptake of ol collection (ofa possible 3<>5) were filled lo these
trace metals Scallops were collected from ic-ordercd dnla sets, wtnch allowed frequcnev ,,iit\
:
SI STUN MPTAl S AM) UIVAI NTS IN TUT SfftlCBKtSUU :7
magnitude of change to be characterised. The
coefficientofdetermination(reportedasR between
— *** "7 - — r-1 1 i t^ ^ rhefitted values (as determined by ihe cosi)ne curve)
— rH c- *- tS r;" — and the eiii|Miieal valuer was determined 10 assess
•J the slrenglli wfseustinal influence;. The residuals (the
values ivmuimng alter seasonal udluenee was taken
into accouiil) were then graphed against lime (in
~r—AC=--? «oit r* rr~i! S—rt^iF*o",_a. —r1«-t -—; ^IarX-O O—g c(mhRertooalnlaonldocgoilnccc)a(e>ln5)t.orradTtehireo)nsRto1advneaddluuecdseepabonesytiwtceiheoannngsoeevsaesrionnlbaionmtdhe
ri metals level deposition arc indicativeofthe strength
ol' the seasonal relationship, these residual values
arc either Ihe result of general unexplained
{ )
variability or can indicate possible temporal iremk
—5--: —*rL, or-r» ^—'. —'-/•* mCf'>. ,.-2_-- »"i-rn, 3—-; S-rr-"i-: 3——; -"—^ crTheraperonardctsteedriainssesdttahtewiisttrihecsalriledyugarsleisgsnviiofainlcuaeansntarloeysvsueelsrt.satArulelneatretwshueelrlUes
- 0.0S level. Results where// o.l are also included.
and are indicated as such Statistical analyses wetv
P £. performed using Microsoft IwciT1 spreadsheets.
Seston and bivalve data were compared with
"~ ' -r !. t. V -c 3 regression analyses (least-squares regression with
'— kC '— IT. C6 D «j seston metal the independent variable and bivalve
mefal ihe dependent variable} using Microsoft K\cci
spreadsheet software. The relationship was
considered significani at /><0.05. The R values
o w^ BJ 5 (coefficient ol delerinination) indicalc what
percentage of the variation in the bivalve metals is
rt ~ 1- ~ —•Ti —— uT. o Ti — dIhuuestao mtheeasruerleatioofnsihhiep swiirtehngIthheosfesIthoenrienlealtailosn,shainpd.
—> c- ? Regression was used since it allowedextremevalues
that could be skewing Ihe relationship(s) n> be
removed and the resulting line compared with the
initial regression line. TOC and particle si/e were
compared with bivalve metal concentrations using
m - 3 w — — •r, *V —m •. «~r. £ • corrclalion analyses. Scallop trace metal uptake
7: ' <-' ri during different seasons ami mussel and scallop
~ M
uptake were compared using correlation analyses.
These resulls were also considered significant when
2 -C -- /><U.05. and are reported as the correlation
-=r -SP£ -=r -!T = •C 3—* <r. fr*"-i": '~ ZO-2 ~Drc--.^F1Tm<V£.5 coefficient squared (R1K)e(MZialrtsI984)_
SpOtiahiliAtribltltXw
- ,v £" Levels of rnelals in Ihe seslon were elevated
5-n .1>, ttJ (compared with the other sites) at ihe four sites
'- T1 - =r s ^—.: "->":J"- ', v- <r**\1 ,-"r'i ,~>c g:uj 5"' cS\llee\ovs0setelsossentsotcfotoonlalllceKactfntHireevtdcedfCsrifrgorenmoeimkfsii'ctaaeWnntVdVum6gtehtcgeaolInsfstl,ah3ii0Lnpe6epv0dienlftgi*hgecug\h.h'aiwnPghnhbeielsli,ife]
levelslifaju, ( d. Cu and Mn al Ihis site ranued From
26i(J 9530 (igg, 4K2 35(. pgyg. SM 211 ftg.g
and 241 921 ttg/g. respectively. Metal levels uu*re
also elevated in seston from sile S2. This site is
locaicd approximately 5 km from the mouth offirst
<>cck and on the edge of the shipping channel
3i3 K, K. ROSS,J. R. BIDWELL. M. WILLI/VMS & J. LiOLANI)
3 a
mm
nun f^Z?l Initialeoncenlnuioii
|5t;;iRk> F7—T7'~1 AInvietiraalgceocnocnecnetnrtartaitoinon 550(1 5i3521i t\iv(leir,aljc;ocnccoenncternattriaotnion
i !
[SSS Finalconcentration
4W
>m 5 5iKI
4mm
MM)
1-
U
P la
L.
SI S2 S3 S-l \VI W3 W6
2HI 120 -
22I0r4i0fmt lI"".^L1 AFInivinetairlaalcgcneonccncorinn'tcliertnartlilrilanitnoinon 1r0in0--- pIi7qTy7V''_'iti AFInixinetairlaalgccoconrccioetin'itecrnealntnliinoHiunlnlon
LI
::. I
i
:'
ft=
s '
life- !
\V1 W.* \V6 \V7 y'hSIiiKl raSM2Ka C-H'S^3&j .KhjSr4-iKL!,WdlnM_JdWi3^M \t.V6
160 Initialflrpinitinti
Averagedeposition
SHI) jij^TTi Initialconcentration 140 - Finaldeposition
Averagecuneeiilralioit
i[S3i Finalconcentration _ I2Q -
I
u m
I
a -JMU
B
a
= HK1
_tlM
in.i " la ;ii b
Fig.3. Levelsoflead(a)zinc(b)cadmium(c)cupper(d)manganese(e)(mg/g)anddepositionrates(F)(mg/day)associaled
with the scston. tnilial and final values indicate the change in seston metal concentration/deposition overthe sampling
period (1997 2000). These are estimated using the residual values (following incorporation ol"seasonal influence),
(initial and filial shaded bars indicate p 0.05. unshaded bars p 0,1, no inilial and final bars indicates no statistically
significant change).
> ,
S! SION MMAI S \MHUVAl\TS \K Mil- M'l N( IK tilU.l "
entering the Port River Levels of Pb in S2 sesfon overdie monitoringpciiod (Fig. 3t).
ranged from 170 >IN tigg Sites Vv i and SI had Lead concentrations in the sesion decreased
Ihe ihml highest levels of metals in sesion. writfl signilkatnly at foui Mies .wer the course ^\' the
l&vttfs oflJb tfijghTjg Irom 35,1) 222 [Ajjjffc. Sues K$, monitoring studv (S2, S4, Wl. Si - although at site
SI W3 and W7 hat! lower levels of meiaK S! p was 0.1 > but increased significantly at Wt>.
js.-oeiulcd Willi (he seston. Mean scroti metal with -30l'n of die variability at these four sites
conectmaiions ftfc presented in Fig. 3u-c. Average explained by temporal changes (Fig. *a| /n leveU
sesion deposition muged from 70 muday (WG. decreased significantly al six >dcs (SI. S2. S3. S4,
VV <'> tp 120 me day (WI)tFig. jrfi, Wl and W3). and remained unchanged at W6 (big.
M'y) Ihere was a less signWif7icant decrease in 7x\
seston conevntratious at [ft I>. figure 5
Ihe influence £if SCQ?0t) on ^Jtffia deposition as piesent examples ofstrong (S2: R - U>56| and poor
deiennmed from Ihe model (y ^ / - a Cfl5 f3?!t/T ' (W(v R - 0.01) relationships tiL-twccti change in
b|y is presented in Tabic 2. There were significant sesion metal levels and rime. ( d leveb, decreased at
(dHovd as *30$i) ijf die votiobilirv in deposition S3 and Wl. und meieased sigriifieanily at \V6 (Fl£-
explained by >e;i>oM;il variation) seasonal trends in 3c). S2 alsi> had a decrease m (\l eolicenU'ations
sc-ston depositionralesal all siteseveept Vw ScWKUj although at a lesssignificant level (/>= 0-1). Coppei
accounted To) ovei half the variation in scroti eoneennations tlLCfeased sigmfieantfv al all sites
depositionatsite_> S3andWl and approximately one (although SI al/>- O.i'i, e>,eept Woand\V7. with no
llnldot"Ihe variation in depositionat silesvSl.S2.S4 ehange(Fig. 3tl» Mnconcentrationsdecreased at Si
ami \V7, Al all sites e\eepl SI.-.e^tvio deposition was S2 and S4. and meivased at Wo IFig. 3ei
-W.16i;\j*illl\ocaIVtiegdlwlcloisnestthehisuthmemeorutftahlalnhtahdetwhientwere,akseistte in1sheossioensmiteetsal>bloe\vveilnsgwtehreemSo4stansdignWilfic(adnetcrcehaasnegems
relaliunship between season and sesion deposition total metals), lollovved by S2 (dcxre.isc). Sv SI, W3,
with an R \alue oi l. lahle 2 also present; ilie VV7. Ihe site closest U> the einuent oullall (WO) was
variables associated with the lilled cosine CUtVCS f« the only site that showed a significant increase in
and h) toreaeliofdiemetals at each site. metal eoiiccHim'k<os o\lT the monitoring period.
As witli deposition, sites Wl and S3 had the
Mimigcsi roIririi>iisHip between total metaJ levelsand Sitttiduri//'i/env/ienitJtvrJw
season, with approximately 4$%ofihevariability in Ml standard reference material (SRM) Zn, (.u and
metal levels attributed toseasonal these sites { table Mn reetwery values fell within the confidence limits
2) I igure 4 (/u rtt S3) n a representative graph ol recovery values published by the suppbei
illustrating the tdalionship between season mid (1720*109,' krO-tl". 7H$*9? fig'g. respceliw_iv1
metal levels. S2 and S4 a'^o had strong seasonal \dditionally. there was no .significant dillereuee
changes in scstnn melal coneenlratioivs. Notably. between the 2 digestion methods foi these thive
Wo. while showing no seasonal relationship in metals. Lead digested with IICIO^MNO, Tell wilhm
deposition, was found to have a relationship theSRMsuppliervaluest714i2'> pg el- alihough I'b
b0.e3t5w).eeVnV7tothaaldmaeiwnelaklevreellsatainodnshsiepasboentwi,emeenanmeRt-a=s (rbeycov1e1r%y).waIs'dlorweecrovuesriyngwaihse l11owOevrIItNhafn;tdhiegeSshRoMn
ievels and season, despite 30"b ol the variation in values forboth digestion methods, with a differenve
deposition being explained by season. SI hat' no of 15% when the ehange was made lo IFCK.UNO.,
rdiiliom.liip between metal levels and season. therefore Pb and C'd values were correeied* by
eveepi lor Via. and \V3 had a relatively shunt' niutliplyiug Ihe empirical values hy l.ll ;nul I 15
relationship between 7.W and scummi. and weaker (Pb and Cd. icspeeti\ely). Oneu the tlifferenee in
relationships between t d and C'u and season, and binding constants between Pb and td tHalistneii &
none with Mn ami season, Murray l°84). it is not clear why these results were
All sites exhibiting seasonal variation id tfttfrtOH obtaincsf Nonetheless, die results were CPUKtstcnl
metal eonccnitadons cscept SI had higher metal and ivprodueible and vvere therclore used lo allow
levels in winter corresponding with the decreased comparison^ between Ihe two digestion methods lo
scstdii de-position in winter, and eouvcrsclv- be made.
increased metal eoneentiaiions in summer,
corresponding with higherdeposition raks.
Ihe scallops all died at Wo in the summer and
icmf!'•>'<!!mini; werethereforenotplacedatthissite inautumn. Al all
here was no significant ehange ovei lime in oihet sites ihcre were few or no deaths ol eithei
I
deposition rates ol any i'l the sites except VV6. R^r seallot^ 01 mussek during the si\-week cxpo.suic
winch a decrease in total deposition was obse^vd period.
K. k.ROSS.J. R. RIDWlLL. ML WIITIAMSA I BOLAND
Taiii.1:3, R: valuesforihcivgtvssUmy iff vt<//%'amimvtal 5a
Pb */n Cd Cu Mn
Scollops(summer) dOSMZ QM PJ5 0.23 ft'4
ScallopsitutuuiiTi) 0.73 0.04 fl.ftol 0.002
QM
Mussels 0.92 0.62 11.44 LI KM
Numbers in italics indicate a significant relationship
(p-(f()5), underlined numbers indicate no change in
(siu.niIk-ant) slopeswhenregressionanalysisperformed ""
Thedaiapoints minusS2andWd.
? ^ S I -
sa^a^r^i
l - - -i r ~ -*-
5b
S |20 11 s W-
HO
H \ /
I
11 I1
10D 200 Jim
LiilliL-tninUa\ofyvar
Tige,mpi4r.icIa:l\saemsptloenmieltlaulsleroainicnegnfrtahieiornelaantdiornhsehilipltehdelcowscicniei- 4t3a'D ;aSC'- %aS.', i—» fv-t :-' iXS s-frt 3xb.'. ---V:_ .^—? ?3- Sr|r .;- '|£- ",i3, 31• c' *=.Z"3 "& a
emvc(graph presentszinc(M siteS3)
Fig, 5. fxamples illustrating the relationship helween
seston metal concentration and lime lifter seasonal
Relationships between sex/on tnefti/ n/n/ hi\</Av umation is taken into account. Uraphs indieuic strnnvi
(-/hie at site S2) (a) and poor (zinc al site \V6) (h)
Table 3 presents a summaty of ihe relationships relationships.
belwccntlie bivalveand seston metalconcentrations.
There were significant relationships belwccn sesion
mid bivalve Pb and Zn coneentralions in both wasremoved, although removing S2 resulted in a 2-
exposures (/><0.05l. There were also significant fold increase in Ihc slope of the regression curve.
relationships between Cd in seston and mussel tissue There were significant relationships in both /n
and between seston Mn and scallop Mn (in summer comparisons|R:=0.73 and0.88).allhough when the
Only). Seston metal levels at site S2 in die scallop S2 poinl was removed from the auiumn data, the
study and sites Wfi and S2 in Ihe mussel stud) were slopes were no longer comparable. This is possibly
significantly elevated compared with other Silas. In the result offewer remaining daia points Ml m the
order tit deiemmic the effect these points had on Ihe autumn exposure compared with summer (6). The
regression curve. Ihc analysis was also performed relationship belvveen mussel and sesion Zn was
with Ihe points removed. The slope ol the second Significantly altered by removing WG from the daia
regression ciu\c was then compared with thai set (R:=0,92 vs_ 03)2) allhough this relationship no
generated with all the data points. Representative longer held when Wfi wasremoved from the data set
graphs illustrating the effecl of removing extreme (R: = 03)2). This was also true o\ the relalionship
values are presented in Rg, 5. between mussel Cd and seston d\ (R-" = 0.62),
The slopesofthe relationshipbetween Pb levels in although no relationship was dctecied between
scallops and Pb levels in seston were not scallopCd and seston Cd.There was norelationship
significantly altered alter removing theS2data point helween hivuhe Cll and seston Cu. There was a
(Table 3). In the mussel exposures, there was no significant relationship between Mn levels in
significant change in the slope when ihc Wo poini •scallops exposed in the summer anil sesion Mn,
1
SI STON MHALSAND HIVAIVliS IN lllKSPf NC IK*.II I II
Tmhi 4.Summan o/H- \nlu<t.\ft'itmiIhiwlyhmetalL-vt7.\ Interestingly. Zn wastheonly metal for which tissue
in ^tittups and metal h\vl\ ill mitSM'h dt/.'loyrtlat flic levels corresponded with the accidental release,
si'sfnnsttiitfth'ngvVfv although all metal levels were elevated ill ihe
Metal R' value eflluenl (Pasrnmco Port Pine, unpub. data). Cu
L7lelaldL itt-ls'7s3 ctohnrcoeurgnhoruattionsthein exIhpeosumruesseplesriowde,reanvdariaMblne
l ;iilniiiiin (MM conceniraiions decreased following pJaccment al the
M(m"ul-pipneier.se 00..10)97 csotnucdeynisritaei,iofnoslldoiwdendotbyappaeasrigtnoifriecaacnth sitnecardeyases.talMe.n
Numbers in Unties indicate a significant relationship
IP 0,05 Discussion
Spatialdistribution ofntnals
although ihe slope nf the regression curve changed While exhibiting varying binding aTfiniiics
significantly when S2 was removed from the data {Balistrieri & Murray lu.S4), metalscan generally be
sel said lo have a preference for the line particle si^e
fraction of sediments (Lead et aL tc>S>9>. In tins
C(iinpari\im hi'twren P alba anil \1. cdulis iitul study,seston was nol sub-divided intoparticlesizeor
seasonal i-omptuisaits (P. ulbuj mass. Morse ctal- ( IWV| state thatsimply reporting
L,0tuJ uiiil7m were (he only metals for which there average Urfnl concentrations can he misleading
was a relationship between the two bivalves (Table because o\' the variation in melal levels associated
4) Levels of Pb in summer exposed scallops wme with different grain sizes. Inourstudy, weaitcmptcd
not significantly different from those exposed in ihe lo aeciuint for some ofthe inlluenee ofparticle size
aniumn. There was also no significant ililVerenee by considering seasonal influences on $C$t0n
between scallop and mussel Pb concentrations. deposition and metal levels, Undci conditionsoflow
Scallop 7,n was not significantly differe.ni helwcon wind and turbulence, suspended particulate mailer
seasons, although scallop Zn conceniraiions were concentrations arc towerandareprobably composed
hi-jherihan mussel Zn at all sites.Thiscontrasts with largely of liner sediments and conversely, stronger
iheinitialconcentraiion.sofZninthebivalves, which windsresuspend agreaternumberot'larger particles,
was slight!) higher in the mussel (issues compared which are comparatively low in metals (Morse w <//.
with the scallops. Cd levels in scallops exposed ih I093).Thereforegramsi/edistribution viiihin seston
the sLimmei were higher than those exposed in the samples is likely lo be the resuh o^ physical
autumn, and Cd levels in scallops in both seasons conditions, which tu Uiin is a result ofseason in ihe
were higher than that hi mussel tissue. Scallop Mn
was sigmficaully higherthan mussel Mn at all sites,
and also in milJul, unexposed bivalves. Table -I
presents a summary of the relationships in inelal
uptake between mussels and scallops.
U)Candparuailutc v/-e distribution
There was norelationshipbetweenTOCorparticle
stye and uptake of any of the meials examined in
ebber scallops or mussels.
TmtpOrtdnptakc
Ijead and Cd conceniraiions til mussel tissue
nieieased significantly until day 28, idler which Ihe
conecnualioiis levelled, indicating mussels hud
reached steady stale. Cd eoiieentianons decreased
significantly following initial transfer to the >ws|iiitlunl|Mimiih.-OHn>'!>)
CunXtpiol$Udfa%\ si2t8e,, wOhniledaZyn 2l0e,velcsonicnecnrteraasteidongsradoufalZlny iegxt6,reOmreadpahtaiRll«i?i>tnroa(isiilggniiiliceaasieuefolrlweaUuiothanrdemaosviaglnioflicaUnut-
increased significantly following an accidental elfeet<h)i>piheslu|K-olHfcline.Inbrokon linefadfCQU!
(r2e/l5e/a9s5)e),ofThZen leelveecltrooflyZten sionluntuii.osnselIrtoimssutehelaskmeenllte>irl cliunnefarukrc-'mjivL-ssinu-iiieilvin;ielsL)t.yfyIgkaolklodnataIipioiiontisnldi>cJa^treesy|l9i5uea"•i•
day 46.. howevei. had relumed tn pre spill levels K-uivssiun line minus the extremepoints [unfilled point)
indicatim.1 some regulation of whole bodv 7m. t grev clashed05 ''<.confidence intervals)
I
12 K.f (U.)SS.J K nilAVMLM.WILLIAMS* 1 HOI WD
Upper Spencer ClulK By considering seasonal (I082f. As noted in the text, however, there were
variability, wc have a belter indication of overall changes in metal concentrations at all sites,
temporal changes in trace metal concentrations. suggesting thai if is likely that there has been tttfjio
SeaM.nal variability does not howeveraccount tor smeller jnfllfcflcc, FfcW£VCr, Ward and Cornell
pailiclc si/e differences between xiks. Normalising [1992} argue thai remote site, global mean and
lot firkin st/c. Using mctaklc ratios or delmmg the minimum value methods ofestimating background
lotal nuu'ibcrof"available binding sites (fad methods concentrations arc less robust than the distance
that allow beiv.eco-siiecomparisonsio be made with extrapolation method used to choose background
rreatei certainly (Morse ct at |99?i Turner & sites lor this study I ach of the four 'background
Milliard :00l>; R.ibstneii & Murray l*>N4). Tim sites can be tlfiffd to deieiminc baekymund
study, hovvev.cr. also assessed Ihc relationship eoneentrulioiis forparticularmetals, however rti)iine
between total seMon metal levelsand bioavailability site has no vardtion in all metals measured.
In ibis study, strong relationships were apparent
between seston l*b and /n levels and Pb and /n S<wvf.>//£// viiruiitOH
uptake ol'holli scallops and mussels, indicating that Deposition rates, were si^mlieantly higher at tttos!
seston metals are I] good indication of the sites m thesummermonths. At that limeofseat both
bioavailable IVaetion of metals. It is under this on and ofMioic v\iuds arc strongest on the Upper
assumption tlvu beiween siie comparisons aiv Spencei (itdf(Aust. Bureau of.Vleteonilogy -2001),
tvp",i.ed. Snutal (5 Haas (1947) als.i reported sivuilicaiu
Notsurprisingly, NV6, thesiteclosesttotheeffluent seasonal vutiabililv in suspended particulate maiicr
discharge sllfi had the highest concentrations ofthe concentrations iutheNetherlands. SI and \\(\did ftol
five metals measured Ilowevcr, sesuiji trace mettfl follow this patleni, probably because of their more
ounimitations jVCIC not :t function 0\ dislunce Iroin protected locations (fig. I). SI deposition was
flit outfall. SI jyaS die same distance from first slightly higher in the summer than the winicrjhe
( reck asS2. althoughS2 had higherleu-Isofall five cause for 1his is not known. W6 showed no
Hieials SI and \\ I had comparable levels ofmetals relationship between deposdton and season.
m msIou even though VVl is further* away from the probably resulting from both iU provimtty to the
outfall than SI <-8 kin from Wo compared with 14 snielter outfall, with the lvsultmg inllnenec ol
km) The concentration gradient for most LrtOlohi variability in suspended matter exiting First I reek,
followed the general current flow in the aren iind us protected loeation
described by fergtison fWKl) While botll SI* atul
Wi vveic locateJ on the shipping eluuinel. which TbtnpHrvI rtvtuh
could cause resuspension ofmetal bound sediments, The lack ofchange over the three year monitoiim'
thereby influencing scston metal levels, the period in scsrou deposition rates at Sf SI S.V S4,
compurabledepositionratesat SI, Slant! WI makes WI, W.n and VV? suggests that only naluial
thai seem unlikely. In a study of metals and inllucnces arc playing a role in seston deposition at
paniculate matter conducted m the North Sea. these sites, v onvetsely. thete was a sicnifieam
lappm ti DA |IW5] eoneludcd thai movement of tlecrease in deposition rates at Wb. indiealtnu either
n;iriico!iiies js generally linked to water circulation an overall decrease in gram si/e being discharged
and mixing IKmi thesmelter(through inuv;Ked ivstdeticv bmeol
The foursites furtherafield (S.v S*l W3, \V7) had theefflueii! inthepondingprocesspriortodischarge}
:>ieuih"cnnily lower concentrations of most meialv or. alternatively, that there iscontinuing 'dilution'of
However. Ihcu 'background" status remains larger,naturalparticlesbythesmallei smeltet diluent
unconfirmed (sec lemporal trends) The levels ofZn :!i.miis tins accumulation ol"finei grains in areas id'
and'" d ai these four sites were similartoone another decreased tlow regimes Itas been rcpv>rted u-lsewIn t>
aVndlWoIwerthanthose foundattheotherfoursitesiS tPuig CJ t/7 I^*)l)j, eomimmly occurring wlien fastvt
Wmi. although levels of Pb and Mil at S3 (lowingcreeks mcel theopensea.
weie highet than a( the otherthree >itcs, as was t ii at (ienetally, metal levels al all sties except Ihc site
W7 This suggests that designating one b\ more of Uoscst to the smelter outfall (Wdl decreased or
Hnj$i siu_^ e»$ .epiescnting background levels lor all i\-mained unchanged over the course of the study.
Oietuls is nut possible. Our background sites were This decrease is likely to be the result of the long
elioNcn based on those published bv Ward e/ .// term ( 20 year) decrease in ihe levels of mctafs
being released by the smeller. This conclusion is
1lwOa\V•VIWtUtKal.CMk.Siiuj*"nii\hM.'i4iSMi>J|it,lVihlvVm|u[rJfilnfteQv\u„l.iTuJjVCiHnfc(«I(kj-WIl\oml sPiurpipe.orutnepdobb.ydactla')llaunemd bmyettahle ddeatcareatsheisimnirnac/oorTloisnh
1I(.*i'1.1'/i.t»v,ih-br'iSl.u".':lAjlimhvl\fI\tv>t;lyVA*.tdll|oup.ni*tii-.niii [litff.Siiiunii|lil;i(AAiliilshltutllQu,SCST.tmtiJiCIiv.<A:m-.lhl.u-iIlkii-i>i CtiisuslufercipioireltueldcboyncLedntyrvaatnieon*s\: Uinovatlhle'Upper Spencer