Volume 3, Number l

RAN COPY O~yNYSGI � 0 � 97-001 C2

Aprtl J 997

Great Lakes

Research Review

great lakesprogram

GREAT LAKESRESKARCkccmeaauss

I

8'orkingfnr Cirereeves A:

The Great Lakes Remuch Review

ABOUT THIS PUBLICATION:

everal years ago, staff from the Great LakesProgram, the Great Lakes Research Con-sortium, and New York Sea Grant realized

an information gap existedbetween peer reviewedjournal articles and newsletter type informationrelated to Great Lakes research. The Great Lakes

Research Review was created to fill that gap byoffering a substantive overview of research beingconducted throughout the basin.

Wis publication i» designed to inform research-ers. policy-makers, educators, managers, ands akeholders about Great Lakes research efforts.

This third voluine l'ocuses on Exotic Speciesof the Great Lakes. The first two-issue volume

focused on the fate and transport of toxic sub-stances and the effects of toxics, while the second

two-issue voluine examined Great Lakes Fisher-

ies issues. All the previous issues highlighted thework of researcher» associated with the sponsor-ing organizations and others who are involved inthese specified research areas.

The Great Lakes Program at the Universityat Buffalo gratefully acknowledges all of thecontributing authors who willingly shared their re-search efforts for this publication, Our apprecia-tion is extended to Charles O' Neill, New York SeaGrant Extension, for also writing the introduction.

Questions concerning this issue may be ad-dressed to the editor, Helen M, Domske, Associ-ate Director, Great Lakes Program, Those who areinterested in obtaining of copies of the first fourissues may contact the Great Lakes Program.

THE UPCOMING ISSUE:

The second issue of Volume Three will also ad-

dress the topic of Great Lakes Exotic SpeciesThose who may have questions concerning thenext issue should contact Jack Marmo, ExecutiveDirectorof the Great Lakes Research Consortium-

Great Lzkes Research Review

VO!. 3, Wo. ], April /997

INTRODUCTION

Charles R. O' Neill, Jr.Coastal Resources SpecialistNew York Sca Grant

N onindigenous species introductions are nothing new to North America, nor are they a narrowly definedproblem, It is estimated that there are currently more than 4500 nonindigenous plant and animal species ~in North America. 'Ibis includes several hundred vertebrates including fish!, mollusks, plants and pathogensthat have established self-sustaining populations. Of these nonindigenous species, about 15 percent have severelyimpacted public health, agriculture, natural resources, and the env~nt. Humans have transported ~140 non-native aquatic organisms, aquatic plants, fish, algae, moilusks, and invertebrates ittto the Great Lakes,which pose a threat to the ecologic integrity of the basin. Several well known examples are the sea lamprey,which caused severe impacts to the native lake trout population and its commercial fishery; the alewife whidtcaused the collapse of the lake whitefish population, leading to a major dedine in yellow perch and othercommercially importattt Great Lakes native species; and the zebra mussel which is dogging municipal andindustrial water intakes, fouling electric generation station cooling systems, and impacting aquatic habitats inthe Great Lakes, the Mississippi River Basin, and other river systems throughout the eastern half of NorthAmerica

In the early INNs, canals became an important vector for introductions. Ihe sea lamprey is sieved tohave reached Lake Ontario attached to barges traveling the Erie Canal, and later spread to the Upper GreatLakes. A nuinber of nonindigenous invertebrates, algae, and some fish, "bitcfthiked" on the stone, mud. or sandballast carried for stability in small, sballow draA coinmercial vessels that traveled up rivers like the Hudson,St. Lawrence, and Mississippi. By 1870, nearly a score of nonindigenous terrestrial and aquatic species plants,fish, and iiivertebrates! had established self-supporting populations in the Great Lakes Basin. After 1870,commercial vessels utilizing water as ballast allowed the introduction of non-native aquatic species which couldnot survive on solid ballast. Another new vector that became manifest during the 1870s was the intentionalintioduction of non-native fish such as brown and rainbow trout and Chinook salmon. Other fish species, broughtto North America by settlers as sources of food, were unltitenhonally released e.g, the common carp!. In aII,almost 50 species werc introduced To the Great Lakes Basin between 1870 and 1930

Since 1930, both intentional and unintentional introductions have axttinued, including the iatea5onalintroduction of the coho salmon and the illegal intrtxloctkui of the rudd by the growiitg baitflsb industry.introductions into the Great Lakes increased dramatically with the openhig of the St. Lawtettce Seaway in the1950s, which allowed larger international vessels to bring in tnillfous of tons of ballast water fdled withhitdihiking non-native spedes. About 40 of the species introduced into Tbe Great Lakes sintx: 1930 are believedto have been the result of such international ships oK-loading freshwater ballast into the lakes, including zebrarnussels. The ruffe, and the round and tubenose gobies.

Only a minority of introduced species cause sev~ damage. IT is possible that sotne non-native speciesmay simply fail to become established as aeif-sttpporting populations when introriuced into a new environmettLOthers may become established as patt of the host ecosystem and thrive, without maja' impan to that ecosystem.In those instances when nonindigettous species become established in a host environmi ut they utilize someresources, at the least food and habitat space, that is then no longer available to native species, Some maysimply bei~ne nuisances. Othets The minority, it is befieved! carve their own niche out of the host ecosystemat the expense of the indigeaous niche holders, spread rapidly. and have major impact on the host environment

Faf ftlore rate is tile nonindigetulus species that can cause lfllpacis tx.'y md ecologic ones, as wldl ihc AsianDam and the zebra mussel which have caused significant damage. to developed infrastructure.

'IMs issue of Great Lakes Research Review offers a lrxik at several receni aquatic nuisance species thaihave becxirne established in the Great Lakes and an insight into their present and future spread and impacts. Ilis important that resource managers have an ecosystem level understanding of lake's response to a number tifstressors aCIng on the system. Since the early 1970s. phosphorous abatement programs have signiticantly reducedthe phosphorous loading to IMe I.rie, with a concomitant reduction in phytoplankt<m biomass. Since Vicintroduction of zebra mussels to thc lake, au additional decrease in phytoplanktott has been observed. as has aninereaae in lakewater Clarity, ntIS raiseS quesVons about Ixissible mussel and benthic inverlebrate hiiiaccumula[jonof such chemicals as PCBs, increase in the flux of PCBs into bcnlhic sediment», und the etfcct of changes inphytoplankton levels and mbr» mussd impacts on particulate cycling on the body burdens of PCBs and otherbioaccumulative chemicals in such sport Ash as walleye and lake trout, ln lit'hat Other Ecoisstern Changes HaveZebra Mussels Caused in Lake Erie; Potential Bioavaiiabitity of PCBs, Joseph V, DePin o aod his colleaguesof the Great Lakes Program at the State University of' New York at Buftalo, address the dcvelopinent andapplication of a saeentng-level stttids-rehra mussel-PCB model for l.ake I:.ric,

Since the zebra mussel was Arst detected in the Great l.akes, observers have been concerned whh thepotenoal impacts on native benthic macroinvcrtebrate Ixipulations in the lakes and tributary streams. JamesHaynes, at the State University of New York College at Brockport, in Zebra Musse!s and JtenthicMacroirtvertebnste Communitt'es of South» estern Lake Ontario: Unexpected Resutt».', explores stinie of Vie waysin Which benthte maerntnVettebrates may anually be benefihing from colonizaVOn of benthiC SubatrateS in J.akCOntario. such as enhancing benthic f xid resources tltriiugh hiodefxisidon aixl by increasing the complexity ofbenthic suhstrates, Are streams that receive zebra inussel larvae-laden water trom the Fsie Canal becomingheavily infesloi by the Iuvadersy 'nus article reveals what Haynes research team has found.

Another ballast water intmlucVon lo the Great Lakes, the ruft'e. is the tocus of Surveillance for Ripe inthe Great Lakes - An Overview, hy Sandra Keppner and her associates at the U,S, Fish and Wildlife Serviceand the Ontario Minis1ry of I'.nvironment, Surveillance programs provide a tneans by which newly establishedpopulalinns of aquatic nuisance species can bc tracked as they expand their range and by which the impacLs otthose non-native species ott native populadons can bc assessed, Such information is of utmost importance toresxiurcc tnanagcrs in devekiping and evaluating umlrol or management programs, 'Jbc Crreat lakes RufleSwveitianee Pttigram has provided ittformaVon on lhe ruffe's natural movement froin its point of introducdonin Western Lake Superior. Its ability to become dominant in Great I.akes waters. and declines in native fish

ipuiatiritts resulting from the ruffe's range expansi !n. 'Ihe Program has proven invaluable in tracking the lishas it has movctt out of I.ake Superior inlo lhe I ower >rest I akes. Keppner's article discusses the three inaincomponents of the Program: tield surveys. angler surveys, and public education.

lite round goby, like the zebra tnusscl. a nadve of Vie Black and Caspian Seas ot' Russia, appears to bctlie fish-cquIvaIent of the zelifa tnusseh robust, aggressive, afld able to dramatically carve out a niche in NorthAmerican ecxisysterns at the expense of native fish species. David Jude, of the Center for Great I.akes andAquatic Sciences. takes a hx!k at the real and Ixitentiai impacts ot this aquatic nuisance species in Round Gobies:Cyberfish of rhe Ttrird Miitennium. Jude attributes thc draniatic dedine in mottled sculpin populations in the St.Clair River to thc gohy, Goby predation on zebra musscls, and subsequent predation by sport fish on gobies isexatnined for Its food chain PCI3 btoaccumuiation potential. Inter- and intra-lake dtspersai by lake freighterballast water aclivities is also addressed

7<bra mussels were first discovered in the Great Lakes Basin in IMe St. Clair in June 1988. Since then,lhe mussels have made rapid headway into North American fresh surface water resources, particularly throughoutthe Great Lakes and Mississippi River Basins and their navigable tributaries. By late-l996, zebra musselinfestatiotts could be found in l9 suites and two provinces. Wle the mussel's physical impacLs on rawwater-dependent InfraSSSuc1me such as pOwer plants, water treatment plants, and industries are weII known.their eccstomic impacts are not . E'conomic impact of Zebra Mursels: Resutts of the 1995 National Zebra Musse~Informasion C earinghouse Study, seekr to rectify thLs. There were 339 facilities that reported total zebramussel-related exlxmses of $69.070,7N! between I989 and I995. Who were the big spcnders? 'ntis paper looksat the economic impact on a watn-use-by-water-use ltasis hint: nuclear power plants spent a quarter oi all lhemoney expended!.

ln those rare instances when an invading organism carries with it the potential for ecologic, economic, andsr!cial impacts. it is impi!rtant that wc have an understanding of the host ecosystent. the invading organism.potential impacts. and how thc invasion might be controlled, 'Ihese infrequent, potentially devastatingintri!ductions point itut the inadequacies i!f existing prevention and control programs and witI serve as the impetusfor developing impri!ved policies and regulations. WhHe there ate still a number of scientiAc and policy issuesthat remain to he addressed by federal, state. and provincial governments heft!re North America can be tx!nsideredto have cotnprebensive pub!ic policies for dealing with nonindigenous species, studies hach as thr!se presentedin this issue of Cre at Loki i Rc" search Review can help to shape the publ/c debates over what future Great Lakesecosystems will hx!k like o our children.

Great Lakes Research Review

Vai 3, Na. I, April 1997

What Other Ecosystem Changes have Zebra Mussels Causedin Lake Erie: Potential Bioavailabihty of PCBs

Joseph V. DePirtto and Rajagopal NcrayarturtGreat Lakes ProgramUniversity at Buffalo202 Jarvis Hall

Buffalo, NY 1426&44�

�16! 645-2088 fax; �16! 645-3667email: depinto@eng.buffalo.edu

Among the key observations are the followingPlTRODUCTION

Lake Erie has undergone tremendous changesover the past 15-20 years. Most of those changes canbe attributed to phosphorus loading control measuresimplemented in the basin. However, soine of therecent changes may be the result of the significantinvasion of' zebra mussels and more recently quaggamussels! to the lake. ln any event, there isconsiderable interest in developing an understandingof these ecosystem changes and how they are relatedto management actions on Lake Erie e.g�nutrientcontrol, toxic chemical load reduction, fishconsumphon advisories, fish management programs!.'loftis interest is evidenced by publications such as theJourrtal af Great Lakes Research special issue on"Evidence for the Restoration of I ake Fme," 19�!,1993 and by workshops such as 'Tire Changing Faceof the Lower Great Lakes Ecosystems," co-hosted bythe New York Sea Grant Institute and the Great LakesProgram at the Umversity at Buffalo February 5,l994!, A!so, the stakeholders within the Lake Eriebasin are currently in the process of developiag andimplementing a Lake Eric Lakewide Management Phrn LaMP!, which has the task of identifying beneficialuse impairments in Lake Erie as a whole anddeveloping and implementing a management pisa foreliminating those impairments. This ~ processrequires the use of an Ecosystem Approach formanaging the lake and, therefore, requires aquantitative understanding of the Lake Erie ecosystemstrur~, function, and response to multiple stresscrrsacting in concert

Effective management of the IAce Erie ecosystemro~ an ecosystem level untierstturdiag of cernstress-resTirnxiR obvious that have been ide~as key to the aew Lake Erie ecor~~em dyruurrics.

Over the past 2I! years there has been a largereduction in phosphorus loadings to the lake. Sythe mid-1980s the loading was reduced by aboutIS, XX! metric tons from about 25,000 metric tonsper year in the early 1970s to about 10,000 metrictons per year �0t!t! mta depending on anrnralrunoff! since 1985. 'Ibis led to a decrease inphytoplankton biomass the base of the food chain!by approximately a factor of two between 1970and 1987 Makarawtcz 1993!, Nicholas andHopkins �993! have synthesized the historicaltrend of aruuial TP loading and phytoplanktonbiomass in the western basin of 1~ FAe from1974-1990 Figure I!. It demonstrates therelationship between phosphorus load reductionsand phytcrplankton response ttuough the mid-19'as predicted by eutroptication models DIToro era1. 1987!. But with the zebra mussel invasirm inthe western basin taking hoM in 1988, we can seean additional decrease in phytophtnkton biomassin 1989-90, with no decrease in phosptuaius loadTbe only logical hypothesis is that it is caused bymussels feeding oa algae, which imposes anadditional algal loss mechanism that must beconsidered in current nutrient-phytoplanktondynamirm models.Algal biomass- decreases su~at to the zebramussel invasions in western Lake Frie andSaginaw Bay have resulted in a significantlyincze:ised water darity. Pre- and post-zebra musselSecchi depth mrurun~mts in Saginaw Bay andwestern basin of Lake Erie show obviousrelationship with the zebra mussel invasion in thesernjsterns Figure 2!.The decrease in particulate. matter in the water

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Fitt¹re L Histarierd trw¹dc cf tie«ri pk«cpkor¹c l<i<rdi¹tt ¹¹d phytapkt¹I<to¹ densitieg i¹ westcrtr Lake Erie{fr<¹rr l<tiekalb' <r¹d Hupki ¹g I ttWJ,

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column <if Lake f:.rie. which is apparently the result<il' a zebra mussel-induced increased flux olparticulate niatter «i the hott<im sediments, shouldalso inCmaSC the AUX <if hydr<iph<ihIC OrganiCcheniicals {H !Cs! such as N Bs Io the sediments<it thc system. Measurements «f 1'CBs in thc s<ifttiShuCS <!I '/@bra niU68CIS <A 1&kc ITIC havC r<lflgedfrom ah<iut I.I-II.C<9g/g {wci weight! {Kreis,personal ciimmunication <it results fnirn a nun<her<it s<iufccs!; there t<ire. tiicre Is fl<l <Iuestl<ln thatxeilfa ni<l!<sels afc pr<lcessfng aA<I hlPaccu<nulatfngK.I3s, Hiiwcvcr, it Is unlikely Ihat their chenucalasslnlfiati<>n cfACIcncy <s IIX!'8, s<1 riot aII of thcniusscl-induced I'CB flux tii thc sediments isiiioaCCUniulat } Ag irl the <i<USsels. MUCh <if <'t <8pr<>hahly residing ln the scdi<nents as rg'.hra musselI<;ce» and pseud<ifcccs <hat is piitentiallyrcsuspendablc «ndhir avaiiahle for exp<<sure toother hcnihic <irgatusn<s.I'inafly, there I» flic <Iucsti<!n <il hiiw the Cirangcsin phyt<ipiankt<in Icvcis an<1 zebra <iiusscl i»<pacts<in particulate inat er cycling is aft'using h<idybufdcrls iit Iil<L<ccuJBUIat]vc chci'nlcais of c<!nccrn BC 's like 1'CHs and Hp! in sp<irt tish like walleye<ir lake <r<iul, Historically. I'CB hi<!accumulation infop predat<ir I]sh has niit been as much <if a c<incernin IMC 4'ie as in Lake !ntarki iir I.ake Miclugan;h<!weVCr, the pOst-lehfa nl<lsSCI I'CB Ic¹CIS Jn LakeHie walleye {I'igure 3! and fake u<iut are A<itdeciimng and may even be irxxeasing IX;vault etaL 19<16; Whittle, Canada Department <if' FISherieSand Oceans, unpublished data!, It i» possible that,due ni the deCrease in water «ilumn SUSpendCQs<iiids <XineentraoOns. there has been a Change in

flic phase distribution of the PCBs remaining inIhc water column toward a higher fracoon ot thediss<ilvcd and therefore bioavailable! fraction,'1'hus, any decrease in total PCB concentration inthe water column is c<i<npensated by a shift towarda higher fraction of the total being bioavaiiable,Ohvi<iusly. a system-lc vel model Ihat

si<nultanc<!usiy ace<!unfs t<ir hydrology and hydraulictransporL nutrient loading and dynamics,phyt<ipiankt<in growth and dynamics, aehra musselgr<iwfh and particulate matter processing, and PCB

Fig¹re 2. $ceehi Depth t¹e¹t¹re¹retrtg i¹ Sagirr<rw 99uy{fre¹t GLEItL littd! e¹d Wester¹ Luke &ie 09r¹riHa%est l&J! pre- <md p<ret-zebrrr rrr¹ssel i¹crrsio¹ i¹tJ<cce sy!i tents.

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Figttre 3. Toial PCB eoneenrrarion in l~ Frie walleye from l977-I992 from Dereudt er aL Ifr96}.

loading and cycling is needed to synthesize the aboveobservations into a. quantitative understanding of themechanisms and process interactions at work in LakeErie, ln an effort to formulate and preliminarily testhypotheses explaining the above observations, we havedeveloped and applied a screening-level solids-zebramussel-PCB model for Lake Erie DePinto er aL 19%;DePinto er aL 1997}.

MODEL DEVELOPMENT

The strategy of conducting a screening levelmodeling analysis for a system prior to developmentand applicatio~ of a morc complex modelingframework has proved to be quite successful inaddressing both eutrophication e.g., Chapra l977;Vollenweider 1975} and toxic chemical problems e.g.,Thomann and DiToro 19g3; Rodgers el aL 1987;Raghunafhan 1990; Fndicott er aL 1992! in the GreatLakes. Screening models can provide valuable insightsabout the behavior of a system without a largeexpenditure of funds to obtain the type of data setnecessary to calibrate and confirm a complex modelingframework. fhrough the apphcaUon of a screemngmodel to already available data for a system,hypothesis formulation and sensitivity analysis canserve to:~ synfhesize what is known about the state of a

system;

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e identify key data and process understanding gaps;facilitate the framing of more complexmanagement questions; andoptimize by identifying necessary «ndunnecessary process terms in the model! the utilityand reliability Ot rnOre COmplex mOdelingframeworks used to address the more complexmanagement questions,The conceptual diagrams for solids and PCBs in

the Lake Erie ZEBRA MUSSY.5/PCS scnerxringmodel are presented in Figure 4. %are solids massbalance �'igure 4a! contains two types of solids sorbents! in the water column biotic~gal biomassand abloti~l other suspended particulate rnatter! ltis important to distinguish sohds type at least ai thislevel because of the obvious diff~a in organiccarbon content and hence PCB partitioning!, settlingrates, sources, and zebra mussel food value betweenviable phytoplankton and other partiariate matter. fbemodel produces biotic solids as measured bychlorophyll a! by a fairly simple phytopianktonpriruary production equation that depends onternperatrjre and light but assumes a nutrieni-saturated~ rate condition. There is a single first-orderconversion of biotic solids to abiotic sohds that lumpsmultiple processes such as algal death and decay andzortplankton grazing and excretion. Bath biotic andabiotic sohds "settle" to the sediments, albeit atdifferent rates; however, once biotic solids enter the

ttt|7tttt Other ~osvitnrt C'/tent,'e~ hav< 7mbra /truuelc Cattcetl Irg1m4 Friz: P<~tt.rrtittl Ih'r~i nitabirin: of Pr:its

MODEL APPLICATION

Table l. Conyarieo¹ of ZhL/PCB eeree¹i¹g ssodel cakakried sreatfy-srare respnese of Lake ~ weerer¹ haei¹ tttirka¹d wirIioar zebra ¹iussefe.

dilterences in organic carbon content. particle density,and resuspension potential heiween zebra inussel fecesversus other sediment material,

Given the above solids dynamics, the PCBtransport and fate follows the conceptual diagramshown in Figure 4b. We assume that PCBs are at localequilibrium with the various solids types, with thepartition coelticient based on a «hemical-specific Yand a solid-specific f,~. Also, air-water exchange isincluded as an additional source/sink of PCBs; astandard two-film mass transfer model DePiuto el al.1994a! is used with a constant gas phase boundarycondition. The bioaccumulation and processing ofPCB s in the zebra mussels is based on a chemical massbalance in an average individual usin.g the same modelframework used for modeling PCB hioaccumulahon inGreen Bay by Connolly er al, �992!, in Lake Michiganby Endicott er al �992!, in Saginaw Bay by Endicottand Kandt �994!, and in the Buffalo River by DePintoer al. �994c!. This basic framework represents thelatest version of food chain bioaccumulation modelsthat have been evolving over the past 10-15 years Thomann and Connolly 1984; Thomann 1989;Thornann er aL 1992; Connolly and Pederson 1988;Gobas 1993!,

'There is an enormous body of literature on PCBtransport. fate and bioaccumulation in lakes. However,two important facts suggests that zebra mussels canplay a significant role in contaminant cychng andbioaccumulation in the Great l.akes, First, we knowthat much of the fate of PCBs in lakes is governed bythe transport and fate of particulate matter, becausePCBs are so hydrophobic. Furthermore, DePinto er al.�994b! demonstrated a very close physical couplingbetween water column and sediment PCBs in IMeF~e through rapid settling and resuspension processesin this system. Second, zebra mussels have been shownto filter out the majority of particulate material fromwaters in which they have been estaMished, providingdirect exposure to particle-bound contaminants Whilethere have been relatively few reports on zebra musselbioaccumulation of contaminants, deKock andBowmer �993! demonstrated significantbioaccumulation of cadmium in zebra mussels, withsteady-state conditions achieved within 40-60 days ofexprusire. Fisher er aL �993; 1994! investigated theuptake and elimination of hydrophobic organicchemicals by zebra mussels, finding relatively highbioconcentration potential. ln additional publications

Axirph V f!epintn and Rajugcrp<rt /taruyanue

from the same overallsludy. Bruner et al. <1994a,f994b! reported that thc rcladvc hi<iaccumulation andassimilation efficiency <if wo PCB c<mgeners from~ater, algae. and suspended sediment was stronglydependent on: total PCB c<mcentration and phasedfatribuliOn, d/etary fraCtion ol algae Versua SeStOn, andtnussel body size and lipid content. 'they also reportedsteady-state zebra mussel BAI's fbioaccumulationfactors! similar lo th<rse found in our saddening modeland a very significant flux <if eliminated PCBs to thebenthic environment in thc form iif feces andpseudo feces.

ln order to examine the impac1 ol r<bra musselson I'CB cycling and bfoavattahility. wc configured ourexeening m<rdel to the IMe I:rie physical system hydividing the fake into tive water column segments anepiliirinion segnrent f<ir each ot' lhe titree basins «nd ahypolimniiin segment f<ir thc ccniral and easternbasins! with an upper fIll xcd sedfnlenf l ayci' bet< iw cactiwater colunin segment where il iaintacts the sediments.iltts segmentadun is Simttar Ui thai uacd by INT<rr<iand Conn<illy f I<!ftti! for their euv<>phicatf<ur m<rdetingin the ntid-I<� fs. except that they ala<i included ametattmni<in layer. Hydraulic transp<irt in I.ake Priewas based <in the prcvi<ius modeling efforts of f!iTor<iand Conn<iffy ll<!II f! and thc recent hydrodynamicnt<rdeiing in I akc I;rie by Schwab and Bedford Schwah 1<!<�: Bedl'iird and Schwah 19<�!. Solarradiati<rn input and lake ten<perature rcginie wereobtained fr<irn N lhA CiiaslWatch data. U.S. WeatherBureau datu und ll.NI't! itr<init<rring data. /<bra andquaggit niurset spaUat densiucs in I.ake Mc for liteearly I<!'!ll» were estintated lr<u» data c<illccted in avariCly it survey» e.g., t.~aCh f'!!'t; I!errlr<it et al.l'W3: Mills et al. I<!<!ll. I'CIt liiading estiniates l'iirI~ke I:rlc are availahle fnurr t!C iI.WQlt l<!tt9! andfr<iin »Ilier triad csliilialiiin studleS Slfaehan andl:isenrcich I9tttt, Kelly <t al. I<!<!.

l'<ir 'flic screening amllysls Iliaf lcd lo tfle ah<!vehypothcs<is. tire rrr<rdcf was applied with and withiiulthe presence ol Ichra musscLs in the lake hut with thesame phyt<iplankt<in gr<i«nh kinetics «nd I'Ctl loading.A c<!nslant I'CB l<iading <if I 2 f ! Kg/yr wasapp<rrU<incd appr<rpriately t<i the ttvec surface waterc<ilunin segrtients ah<rut 2/3 i!f the t<rtat lirad worn toflic weStern basin because <!l' the impact iif the I'!eV<!itRiver!. A c<»nparfs<in of the steady-state tuodel outputliir tire western basin is presented in 'I'able I as averagevalues during flic April- Xtoher growing seas<in. N<rtethat even though the total water column I'CBconcenfrati<in is decreased in ihc presence of zebramtrssets. the fractiiin *'dissolved t J! increases Ir<imf!.4l without 'A:brd mussel s lo 0.%5 when libra mussclsare part of thc ecosystem, This is because for chemic.alslike PCBs with log l4,'s in lhc range»l 5-6! thefraction dissolved is a strottg luncfiori ol suspendeda<Aids concentration in the range of f-20 mg/L. ln

conjunction with the incrcasc in f<l. «e saw a verysignificant Increase in thc mass-specific c<inccntrationof PCB in lhe biotic solids froin 1N! to 3fl<! ng/g!.'lhomann f989! and others have indicated that foodchain bioaccumulation <if hydrophobic cheniicals arequite sensitive to phyl»plankton BCF bioc<rncentrationfactor!; therefore, all else being equal zebra musselsmay he causing an increased bioaccurnulati<in»f PCBsin lhe pelagic food web.

At the same time as we estimated increased hfottcsolids VCH content in thc water column. we foundhigher sediment levels fr<rm 4.g to 8,3 ng/gi, 1%is lsattributed to the higher nct deposition rate of solidsmediated by the zebra mussel filtering process, Higherscdirnent PCB c<rncentrations suggests higher PCBbi»accumulation potential through the benthic foodchain.

CONCLUSION

'I'hc /EBRA MUSSELS/PCB screening levelmodel described above presents a logical argument forthe following hypotheses, liven Ig change in theI'CB t<iading to I ake Erie, fhc presence of zebrarnussels al reas<>nable densities will have the followingtwo impacts in the lake:

~ The invasion of:cbrit rnrrssels in Lake Frr'e r'sredirecting the flow of energy, carbon, andphosphortrs from the pelagic grazing} food chainto the h<.nthic detrital} food chain, Zebra musseLs'are out-competing planktonic herbivores foraraochthonously prodt<ced organic carbon. By thiss/<tinting of parti<.'ulate nratter to the sediments, the�-r bra mrtssel invasion is car<sing an alteration ofphvtoplankton and phosphorus dynamics in thewater colunin during the growing searon andthereby leading to increased total PCB Jlus tob<itrom .iedi ments, whi ch creates increasedpotential for bioa<cumulation in the benthic foodweb.

By decreasing the concentration of particulatematter lioth biotic and abiotic} in the watercolttmn, the =ehra nrr<ssef invasion is causing anincrease in dissolved bioavailable} andntass-spec<Jrc algal phase PCB concentrations inthe water column. thus also creating a potentialfor r'ncreased bioaccumt<lation in the pelagic foodweb,

Of course, theSe pOlential ecosyStem intpllcatiOnSof the zebra mussel invasion in Lake Erie must hefurther tered by connnued evolution Of ecosystetnm<rdels such as described in this paper. %his evolutioncan only be reahrnd by continued data cottec6on andpiticess experimentation in a range of tea<"trdt areas,

Mrbut Other l~ usystem Changes have Zebra MasseL~ Caused tnLake Er e: Patentiut Bioasailabihrv af PCBc

including such topics as: developing a quantitativeunderstanding of the fate of particulate matter andassociated pollutants that are filtered out of the watercolumn by zebra mussels; and obtaining betterestimates of mussel densities, age distribution, andPCB body burdens in the lake as a function of spaceand time.

REFERENCES

Bedford, K.W. and D.J. Schwab. 1994. The GreatLakes Forcasting System - Lake Erienowcasts/forecasts. MTS '9l, R. Spango ed.!,Marine Tech. Soc., Washington, DC. 432-436.

Bruner, K.A., S.W. Fisher, and P.F. Landrum, 1994a.The role of the zebra. mussel, Dreissena

polymorpha, in contaminant cycling: L Ihe effectof body size and lipid content on thebioconcentration of PCBs and PAHs. J. Great

Lakes Res, 20�!:725-734.Bruner, K.A., S.W, Fisher, and P.F. Landrurn. 1994b.

The role of the zebra mussel, Dreissena

polymorpha, in contaminant cycling: Il. Zebramussel contaminant accumulation from algae andsuspended particles, and transfer to the benthicinvertebrate, Gammarus fasciatus, J. Great LakesRes. 20�!:73S-750.

Chapra, S.C. 1977. Total phosphorus model for theGreat Lakes. Jour. Environ. Eng, Div�ASCE.I 03 EE2!:147-161.

Connolly, J.P. and C.J. Pedersan. 1988. Athermodynamic-based evaluation ot organicchemical accumulation in aquatic organistns.Environ. Sci. Technol. 22 I!:99-103.

Connolly, J,P., T.F. Parkerton�J,D Quadrini, S,T.Taylor, and A.J. 11tumann. 1992. Developmentand application of a model of PCBs in the GreenBay, Lake Michigan walleye and brown trout andtheir food webs. Technical Report to Large Lakesand Rivers Research Branch, U.S. EPA,ERL-Duluth, Cnnsse Ile, Ml.

DeKock, W,C. and Bowmer, C.T., 1993,"Bioaccumulation, Biological Effects, and FoodChain Transfer of Contaminants in the Zebra

Mussel Dreissena polymorpha!," ln ZebraMusseLs: Biology, Jmpacts, and Control, Nalepa,T.F and Schloesser, D.W� eds,!, LewisPublishers, Baca Raton, H.. pp, 503-533.

DePinto, J.V,, R.K Raghunathan, P.M. Sieaenga, X,Zhang, V.J. Bierman, Jr., P.W; Rodgers, and T.C,Young, 1994a. Recalibratt'on of GBTOX- AnIntegrated Exposure hfodel for Toxic Chemicalsin Green Bay, Lake Michigan, Technical Rept'

submitted as part of Cooperative AgreementCk-818560. FRI.-Duluth, Idge Lakes and RiversResearch Branch, Grosse Iie, Ml, 48138, 139 pp,

DePinto, J.V., P.W. Rodgers, and T. Fiest "When dosediment-water intereactions control the watercolumn response of large lakesto toxic chemicalload reductions'l" Oral Presentation at 37thConference on Great Lakes Research, IAGLR,Windsor, Ontario {June 5-9, I994b!.

Derrnot, R., J. Mitchell, I. Murray, and E. Fear 1993Biomass and production of zebra rnussels Dreissena polymorpha! in shallow waters ofnortheastern Lake Erie. In Nalepa and Scloesser eds.!, Zebra mussels: Bioiogy, Impacts, andControL Lewis Publishers, CRC Press, for., BocaRaton, FL. pp. 399-413.

Devault, D.S., R. Hesselberg, P,W. Rodgers, and T.J.Feist, 1996. Contaminant trends in lake trout and

walleye from the Laurentian Great Lakes. J. GreatLakes Res. 22�!:884-895.

DiToro, D.M. and J.P. Connolly. 1980. MathetnaticaiModels of Water Quality in Large Lakes, Part 2:Lake Erie. Report No. EPA-600/3-$MAS, reportto Large Lakes Research Station, FRL-Duluth,Grosse lie, Ml 48138,

DiToro, D.M., N.A. Thomas, C,E. Herdendorf, R.PWinfield, and J.P. Connolly, 1987. A post auditof a Lake Erie eutrophication model. J. GreatLakes Res 13�!:801-825.

Endicott, D.D., W.E.. Richardson, and D.J, Kandt1992. MICHTOX. A mass balance and

bioaccumulation model for toxic chemicals in

Lake Michigan. Tcchnical Report, Large Lakesand Rivers Research Branch, U.S, EPA,FRI.-Duluth, Grosse Ile, MI.

Kndicott, D.D. and DJ. Kandt 1994. Far Field lUIodelsfor Buffalo and Saginaw Rivers and Food ChainBioacc~ulation Model for Saginaw RiverlBay.Technical Report prepared for the ARCS/kVBAwork group. Large Lakes and Rivers ResearchBranch, U S. EPA, KRL-Duluth, Grosse Iie, Ml.

Fisher, S.W., 6ossiaux, D.C., Bruner, K,A�andLtndrmn. P+., 1993. "Investigations of theToxicokinetics of Hydrophobic Contsanlnants inthe Zebra Mussel," ln Zebra Mussels: Biology,Impacts, and Control, N al cpa, T F. andSchloesser, O.W., {eds.!. Lewis Publishers, BocaRaton, H pp. 469-490,

FLsher, S.W., Bruner, K,A.. and Landrum, P.F.. l994-"Trophic Transfer of EnvironmentalContarninants by Zebra Mussel, Dreissenta

Joseph V. Oepzaro deut Rajugopai Naruyanan

polyrnorpha." Presented at the 37th Conferenceof the International Association for Great LakesResearch, brune 5-9, 1994, Windsor. Ontario.

Gobas, F.A.P.C. 1993. A model for predicting thebioaccumulation of hydrophobic organicchemicals in aquatic food webs. 'application toLake Ontario. Ecological Modeling. 69:1-17.

Great Lakes Environmental Research Lab/NOAA andU. of Michigan Cooperative Institute forLimnology and Ecosystems Research CILER!.1994, The Ecological Approach to the ZebraMussel Infestation in the Great Lakes.Publications Oftlrce, NOAA, Ann Arbor, Mi.

Great Lakes Water Quality Board. 1989, Report onGreat Lakes Water Quality. International 3ointCommission, Windsor, Ontario.

Griffiths, R.W.. Schloesser, D,W�Leach, 3.H., andKovalak, W,P., 1991. "Distribution and Dispersalof the Zebra Mussel Dreissena polyrnorpha! lnthe Great Lakes Region," Canadian Journal ofFisheries and Aquatic Scierrces, Vol, 48, pp.1381-1388.

Holland, R.E. 1993, Changes in planktonic diatoms andwater transparency in Hatchery Bay, Bass Islandarea, western Lake Erie since the establishment

of the zebra mussel. J. Great Lakes Res.19�!:617-624.

Kelly, T.I., j,M. Czuczwa. et aL 1991. Atmosphericand tributary inputs ot toxic subs'tances to LakeFme. J. Great Lakes Res. I7f4!;504-SI6.

leach, J.H. 1993. Impacts of the zebra mussel,Dreissena polyrnorpha, on water quality andspawning rmfs in western I~c Eric. In Nalepaand Schloesser ec}~,!, Zebra rrurssels: Biology,Inrpacts, and Control. Lewis Publishers, CRCPress, Inc.. Boca Raton, I=L. pp.381-398.

Makarewicz, J.C, 1993, Phytoplankton biomass and itsspecies composition in lake Ixie. 1970 to 1987,J. Great Lakes Res. I9�!:258-274.

Makarewicz, J.C, and P.E. Bertram Eds.!. 1993.Evidence for tire Restoration of Lake Erie. SpedalIssue of J. Great Lakes Res. 19�!;197-309.

Mills, F,I.�R.M. Dermott, E,F, Roseman, D, Dustin,E, Melina. D.B. Conn, and A.P. Spidle, 1993,Colonization, ecology, and population structure ofthe "quagga" mussel Bivalvia: Dressenidae! inthe lower Great Lakes. Can. J. Fish. Aquat. Sci.50;2305-2314.

Nicholls, K H. and Hopkins, G.J., 1993. "RecentChanges in Lake Erie North Shore!Phytoplankton: Cumulative Impacts of

Phosphorus Loading Reductions and the A braMussel Introduction.' Journal of Great LakesResearch, Vol. 19, No. 4, pp, 637-647.

Raghunathan, R.K, 1990. Development of a dynamicmass balance model for PCBs in Green Bay. M,S.Thesis, Clarkson University, Potsdam, NY.

Rodgers, P.W., J.V. Depinto, T. Slawecki, and W,Booty, 1987. LTI Taxies Model Application:PCBs in Lake Ontario - An Exploratorv Analysis.Report to IjC Task Force on Chemical I~iadings,Windsor, Ontario.

Schwab, D,J. 1994. Initial implementation of the GreatLakes Forecasting System: a real-time system forpredicting lake circulation and thermal structure.Water Poll. Res, J. Can. 2I3:302-220.

Schneidcr, D.W., 1992. "A Bioenergetics Model ofZebra Mussel, Dreissena poiymorpha, Growth inthe Great I akes," Canadian Journal of Fisheriesand Aquatic Sciences, Voh 49, pp. 1406-]416.

Spidle, A,P., J.E. Marsden, and B. May. 1994.identification of the Great Lakes quagga musselas Dreissena bugerrsis from the Dneiper River,Ukraine on the basis of allozyme variation. Can.J. Fish. Aquat. Sci 51:1485-1489.

Strachan, W.M.J. and S,J, Eisenreich. 1988, MassBalancing of Toxic chemrcals in the Great Lakes:The Role of Atmospheric Deposition. Report toScience Advisory Board, UC, Wrndsor, Ontario.

Thomann, R,V, and D.M. DiToro, 1983.Physicochemical model of toxic substances in theGreat Lakes, J.Great Lakes Res. 9�!:474496.

Thomann, R.V. and J.P. Connolly, 1984. Madel ofPCB in the Lake Michigan lake trout food chain.Environ. Sci Technol, 18�!;65-71.

Thomann, R.V. 1989. Bioaccumulation model oforganic chemical distribution in aquatic foodchains. Environ. Sci. Technok 23�!:699-707.

Thomann, R.V., J.P. Connolly and T.F, Parlrerton.1992. An equilibrium model of organic chemical~ation in aquatic food webs with sedimentinteraction, Environ. Toxicol. Cheer.] I:615-629.

Vollenweider, R.A. 1975. Input-output models withspecial reference to the phosphorus loadingconcept in limnology. Schwer'zerische Zeitschrifrfur Hydrologic. 37:53-84,

James M Haynes

Foie Canal Sa!mort Creek Si nificant?Parameter

NoNoNoNoYesYesNoNo

Temperature oC!pHCalcium rttg/L!POC mgfL!Vel igers �' L!Chlorophyll g mg/L!Velocity m /sec!Discharge {m'/sec!

19,4

72.521.6

4.60.050,08

19.67.9

62,921.5l4. 3

7,90.090.07

~~ ~. ~~soll af rmeNW pbysicg ckenkel ~ biolat~ caaditioas seorr relirvmet 4o lebrm naegsgg biology insbe &ie Ceaal nad ~n Creek.

10

following Dreissena invasion are possible, However,scardty of pre-invasion data has made assessment ofOreissrna impacts nn pre-establishedmacr@invertebrate taxa ditTicult, ln 1991-1992. weused the same location, study design and samplingrnettuads as those of Bader {1985!, who quanUfiedabundances of benthic macroinvertebrate taxa in 1983.seven years before the establishment of Dreissena inLake On@trio. Futi details an: in Stewart «nd Haynes�994! and Stewart �993!,

ln 1991-1992, zebra rnussels comprised up to 93'Ãof the rnacroinvertebrates insels. crustaceans, worms,snails, etc.! collected, replacing thc amphipodsideswimmer Gammarus fasciarus! which was thenumerically dominant taxon in 1983. However, thetotal abundance of non-Dreissena marut>invertebrateswas significantly greatq in 1991-1992 range; 1,316 ~170 to ~,267 g 523 /m '! ihan in 1983 range; 127 g41 to L159 ~ 107 /m !. Taxa showing the greatest2

increases in abundance included the annelid worms Manayarrkia speciosa, Spirospernta ferox! andunidentified tubificids; the gastropod snails Helisomaanceps, Physa hererostropha, Sragmco]a carascopirrm,Vaivaia rricarinara, Goniobasis livescens, Amnicolamimosa!; the sideswimmer Gamnrarr<sfasciaras!; thetrichopteran insect fPofycenrropus sp,!; and thedetmpA caayfrsh Orconecres propinqtris!. No taxon

was less abundant in 1991-1992 than in 1983, ardcomparisons of macroinvertebrate communitysimilarity in 1983 and 1991-1992 range: 50 to 99%similarity! indicated that previously establistmd taxadid not change substantially between 1983 and1991-1992. The number of taxa collected wassignificantly greatn in l991-1992 maximum: 32 persample! than in 1983 maximum: 15 per sample!.Whi/e taxa of numerical importance in 1983 remainedimportant in 1991-1992, some taxa of tittle numericalimportance in 1983, such as the oligocbaete worms Srylaria iacnsrris, Poramorhrix vejdnvskyr', 5'. ferox!,and the snail Anrnicoia hmosa!, were of increasedimportance in 1991-1992, No taxon exhibited asignificant popu!ation decline between 1983 and1991-1992.

Population changes ot some taxa are similar tothose reported by other researchers who have studiedimpads of Drrissena on benthic rnacroinvertehratecommunities in Lakes Erie and St. Clair Dermott eraL 1993, Grlfiiths 1993!, Although other factors mayhave contributed to the changes observed, our resultssupport theories that Dreissena is facilitating thetransfer of energy to bottom organisms bypseudofecal/fecal deposition, that mussel colonies areproviding habitat for additional invertebrate taxa, andthat predicted disasterous dranges in native benthic

Zebra brttsseb and Hettthi<' Afarroinvettebrate Commttttities of Sotttlnrv ttrrtt Lour Onttttio ttnttb'el''t.tetr r'ribtttariei' Uttt~< ted Retttrte.'

OptimumRange Makarewicz �989! Salmon Creek

ToleratedRangeParameter

Temperature oC! 0 � 30 'pH 4,6-9.5 b8.3Calcium mg/L! ! 40 "Current m/sec! > 0- 2.5"'Food Particle Size lrrn! 1 - 450 b r s

20-25 ~8.2- 8.6 b

1- 27 9-277.5 � 8.5 7.3-

49- 1180.03 - 0.16

not exam ined

! 50a,c01 1 dc15 45 b,r,g

61 � 68< 1

not reported

'Kovalak 1989, 'Morton 1971; 'Sprung 1993, 'Smirnova and Vinogradov 1990, %'Neilland MacNeill 1991, rSprung and Rose 1988, sTen Winkel and Davids 1982

Table 2. Tokrated tttstf optimtd rttnges of importttnt environtnenrttl pttranterers for zebra «tttssebt. Mattarewt'ezreportetf water qaaitty der for nearby ~kt'n, 8ttttonwood and Worrkrtep Creeks.

macroinvertebrate communities except for freshwaterclams! have yet to occur in Lake Ontario,

Dreissena may facilitate transfer of nutrients tobenthic macroinvertebratcs by filter-feeding on openwater phytoplankton and subsequently depositingwastes on the bottom. Dreissena feces andpseudofeces are important in diets of benthicmacroinvertebrates that eat detritus dead organicmaterial!. Facultative or obligatory detritivores withpopulation increases in our study were S ferax andother tubificid worms, the snails P. heterosrrrtpha, V.rricarinara!, the arnphipod �, fascrarrtsJ, and theinsect Palycenrroptts sp,!, Other researdrers havefound the abundance and biomass of many benthic.invertebrates, induding detritivorous oligochaetewanm and midgefly {chironomid imect! larvae, to begreatest anrong clumps of Dreissena where feces andpseudofeces accumulate.

Enhanced substrate complexity also maycontribute to incn~ aburtdarrce and diversity ofmacroinvertebrates. By creating an intet'.stihal ne~that may increase ~ available to othrM benthicorganisrus, Dermott er aL �993! suggested thatDreissentg was responsible for hrcre@es in Ganrmarrss

sp. observed on bedrock substrates colonized bgOreissena Griffiths �993! likewise attribtrtcdpopulation increases of leeches, snails, sideswirumern. Polycenrropus! and the midgefly Polypedilrrm sp.! isaLake St. Clair to increaseti substrate heterogern:l~provided by Dreisserta. Of these taxa, only let~@and Polypedtiurn failed to show signi5cant populationsincreases at our study sites between 1983 artd1991-1992.

Dreissena may indirectly create berrdric habitat anweU, Filter-feeding improves water clarity throuWremoval of suspended partldes. The resulting increa'-~in the lighted water zone, in combination withirtcreared transfer of nutrients to the lake bottom MDrtissena, may ptorrrote growth of benthic vascularplants aquatic waxy!. Positive relationships bet%~benthic algae and populations of nematode ron~worms, naidid oligochaete worms, ieeches, stra+~ Gymmhv sp., He!isola sp, Physa sp., Valvara sp-.Goniobasis sp�Amucola sp.!, sideswimnrers, rnayflY ephemeropteran insect! larvae and rnidgetly larvas-bave been reported from the &eat Lakes in the ~ Cook and Johnson 1974, Batton and Hynes 197lt~-Grlfllths �993! believed that increased densities

Haiku vjanus M

12

subtnerged vascular plants and henlhic, algae frif lowingcwiforrfz~n of l.ake St, Clair hy Drrisserra uintrihutcdto the observed tncreasc in macroinvertehratepopulations there. A variety of filamentous green algaewere present at our study sites in I'983 and in199I -1992, and nracroinvertebrates, especially theskfeswimnrer �, Irncf'clfrcv!, %'erc ass<related willi fhealgae.

Whik midst macrofnvertebrate population changesobserved in our study may be attrihutahie to Drnssrrra,these changes nray «Lsti rufle' changes ln water quality ir lushnat condittons that are unrelated to the l!rrfssrrrrrInvasion, Phosphorus abatement programs havecontributed tti declines in total phosphorusconcentrations throughout Lake !ntarlo since diernid 197 ls, but assessing fhe effects that phtxplurrusabatement hscs had arid will c intinue to have on benthicrnavrtlnvertiWate piipufafions is pr»hlematic, Johnsrinand Mac'Nell I9ft6! attributed declines in theabutkknces of sante rttigridim1e worm. sphaerlid clamand isopttdiscM tax.a in the Hay rif Quintc to rcductioiLsin phnspfurnts loading «i I Me !ntario. Ilarton f 19ft6!observed declines in total henthii ntacnrinvertehrateabundance in areas undergoing rapid dew utrriphication,but noted that species diversity allen increased undersuch ctxtditfons. Increased overall abundance ofberlfhll: nlacfoinvertebrates. Irlcludlrlg at iciest oneworm taxon S. ferra! known to inhabil nutrient-richhabltats. suggest nutrient dqxtsitkin by Dreisserru hasreve than coinpe~ for ollgtttrophication processesin Lake Ontario between 1983 and 1991-1992.Increased wafer clarity resulting from decliningphhsphorus concentrations. in combination withDrri,i~'rrrrr flltn-feetfing, also may lead to a deeper andwarmer epilimnirin Mazumder 1990! which mayfurther increase benthic production,

Other studies conducted within the Great Lakesstningly suggest Drr i crrifn ls threatening clams of thefamily Unionidae hy settling on their shells andpossibly Inhibiting their ability to feed, respire, andreproducie cf. Mackie 1991!, !ur study did nttt focuson freshwafer clams and failed to show tltat 1Jreisserrrris negatively affecting other bentllrc nuKrt!Invertebratetaxa. Our data soggier that l!rer'.strrrrr tuLs thus far hada prisftive Impact on many henthk ntacroinvertebratertpecies in scruthwestern I~ !nfarlo,

STUDIES IN WESTERN NEW YORKCREEKS

Ibe New York Slate Erie Barge Canal, with adirect connection to Lake Erie, was colonized by zebra~s in 1989, Many of the creeks and riverscrossed by the canal rerxive water from it from Aprilthrough Nnrrtnnber. Dense colonies of zebra ntusselswere ohtterved at canal water outfalls tn these creeks

as early as I99t!. hut none of six oeeks exatnined inMonroe County, Ncw York. has zebra r»ussels morethan itlt! m downstream from where canal dischargisenter,

Salmrin Creek was chosen tor study sec Millerd Haynes 1997 and Miller 1994 for full details <if

methtrds and results! %+ause there was no apparentreason why zebra rnussels should not successfullycolonize the reek. R<icky subslrates suitable I'orattachmertt are abundant. and invertebrate and fishcommunities indicate a reasonably healthyenvironment. Aside from agriculturaJ and suburbanrun-otf crimmon lo all streams in the region, there isrui evidence of point source prtflutfon in the watershed.We examined water quality temperature, pH, calciumcarbonate <xincentratlon!, physical crindttions current.suhstrafel. and biological conditions farxI supply,predation> to learn why zebra niussels have nett becomeestablished,

Water temperature, pH. calcium carbrmateoincentration, and current velocity in the lme CanaIand Salmon Creek did nuit differ significantly duringthe sampling pi'riod {'I'able I!, and they can beeliminated as factors reducing zebra mtlssel abundancein the creek, ln fact. physical and chemical conditionsin the creek were generally in the optimal ranges forthe survival, growth and reproduction of zebra musseis 'I'able 2!.

I'rsh of I I species were collected from SalmonCreek and the canal oulfall channel, but only one zebramussel was found in the stomach of one tish,Although crayfish abundance in Lake Ontarioincreased after colonization by the zebra mussel Stewart 1993!, and predation on zebra rnussels bycrayfish has been observed in controlled settings, theabundance of crayfish ln Salmon Creek does notappear to have changed. Predation alscr does nofappear to be a likely factor limiting zebra musselabundance ln Salmon Creek

initially, we hypothesized that food supplies forzebra mussels measured as particulate organic carbon,P !C, in the water! would decrease as canal waterntoved over the existing zebra mussel colony in theoutfall channel and was diluted by Salmon Creek, bu'tPt!C did not difler between the canal and the neckfTable I!, illus, food quantity, as measured by POC,was eliminated as a factor limiting zebra musselcolonization of Salmon Creek.

The abund:mce of veligers and the ccutcenfmfionof chlorophyll It dropped sharply after wstter left theBie Canal Table 1!. In fact, velfger counts drop>cd%% or more and chlorophyll g Ieveis dropped by anaverage of 87%- less than 15 m dawn the ~leading fnnn the canal to the creek. Maxfmnm-densttks of Dreisrenn larvae were M/L in the canaland 23/L in the aeek Maximum ch1orphyli a levelswere 21.7 ntg/L in the canal and 7.3 mg/L in the creek

Zebra Masse& un' Benrhic Mui roinvertehratr Ccwtvttunuie~ rif Xoru/nveslern Lg4 Onrari~ an>5ei nod? nbutaries. Unexperied Reculrs!

CONCLUSION

l3

What reduced veliger counts and chlorophyllconcentration atter the canal outfall' ?

Near the base of the canal outfall channel toSalmon Creek is a dense colony ot' adult zebra musselsand a small wetland. Part of the water flowing out ofthc canal forms a back eddy that tlows through thewetland, Adult zebra mussels were observed attachedto vegetation in the wetland, suggesting that someveligers become trapped and settle in the wetland.That this may occur in Salmon Creek was supportedby sampling in Brockport Creek. The canal dischargeto Brockport Creek meanders through a wetland betorereaching the creek, No adult zebra mussels were foundin the creek, but chlorophyll p levels were much higherafter water passed through the wetland than they werein the canal. This suggests that the wetlands associatedwith canal outfall channels produce phytoplankton butprevent veligers from reaching the creeks.

Literature published beiore 1993 indicated thatfood particle size, not composition, is the critical aspectof diet for zebra mussels; 15 to 45 m is the preferredsize range, but l to 450 m particles can be filtered andingested Ten Winkel and Davids 1982!. Later studiessuggest that food quality also is important, Stoeckmanand Gerton Ohio State University, Columbus, Ohio,personal commurucation! found better survival amongcultured zebra mussels using a commercial diet ofmarine algae higher in fatty acids than the control diet.Vanderploeg er al. �996! reported that the key toraising Dreissena in culture is providing the rightalgae, particularly freshwater Chlor elhr miriurissimaand marine Rhodomorras minura, both about 3m indiameter and rich in long chain polyunsaturated fattyacids. Mowever, Wright er al. �996! reported that twoDreissena species survived and grew better on smallphytoplankton high in saturated fatty acids. Qearly,small food size is important to veligers, but more workis needed to precisely define key components of theDreissena diet and how diet requirements mayinfluence where mussels can colonize successfully.

The Erie Canal has many of the physical andbiological properties of a lake, among which is thepresence of phytoplankton and bacteria suitable forzebra mussel feeding. Chlorophyll a levels in the canalwere consistently higher than levels in Salmon Creek.The high abundance of' zebra mussels in the canal isundoubterly related to its rich food supply. Becausephytoplankton do not readily occam in streants and 87%of canal phytoplankton me~ as chlorophyll 4 isfiltered by adult Dreisserra before teaching the creekit is quite hkely that the POC of' Salmon Creek doesnot rueet the quaRtative uutrihonal ~ments ofzebra musmls.

Just as adult zebra mussels at the base of the canaldischarge to Salmon Creek appear to filter Nestphytoplankon out of the water, it is likely they are alsofeeding on the larvie Smirra~ and %nogradov 1990!

coming from the canal and create the 60% reductionin numbers observed.. The dense population of adultDreissena in the discharge channel appears to be a"biotic sponge" which removes veligers andphytoplankton from the canal water flowing intoSalmon Creek, thus depriving the creek of aftpropriatequality food phytoplankton! and a source of larvae tosupport colonization of the creek,

Why have zebra mussels not colonized othercreeks in the region? Ate wetland between the canaland Brockport Creek apparently prevents veligers fromreaching the creek. Near their outfalls, Aliens andNorthup Creeks have predominately muddy bottomsunsuitable for zebra mussel attachment and filterfeeding. Thus, it appears that zebra mussels are havinga diKcult tirue colonizing streams fed by the ErieCanal in Moruoe County, New Yak.

By occurring in large clumps and Alter-feedhtgintensively, Dreisseria may benefit otherrnacroinvertebrate taxa in Lake Ontario by increasingthe complexity of benthic substrate and by iongthe flow of energy to benthic environments. Whilesome factors e.g,, increased water clarity due toDreissena bioBiltration and phosphorus abatemeiitprograms! may be acting synergistically to favorablyimpact benthic organisms, biodeposition by Dreissenamay keep benthic food rescatrces at high levels despiteoverall declines in fertility of the Lake Ontarioecosystem. Given the apprctpriate physical habitat andwater quality conditions and an abundant samm ofveligers, four factors appear to limit colonizanon ofregional creeks by zebra rnussels: l! Partial retentionof zebra mussel veligers by wetlands through winchthe canal discharges often flow, 2! Filtering ofphytopl~ and veliger larvae by adult Dreissenaoften found at the beginmng of outfall ch:mneis fromthe canal to creeks, 3! inappropriate food quality e.g�lack of sruall-diameter phytoplanktrm with irnpcaiantfatty add constituents! reaching creeks from the canal,or 4! Muddy substrates inappropriate for attachmentand filter feeding by Dreissena. Considering the manydire warnings of impending ecological disaster afterinvasion by zebra mussels, these results areencauraging. Our research team continues to tnonitorfor ln~tial longer team changes, but so far it apped-that the zebra mussel has not greatly changed benthiccommunities in lakes and streams in our part of theGreat Lakes basin.

I thank Timothy W, Stewart and Steven J. Millerwho wrote the M.S, theses upon which this paper isbased.

James tie. Haynes»

LITERATURE CITED

Bader, A.P. f985. Dynamics of benthictnacroinvertebrates inhabiting an artificial reef andsurnntnding areas in southwestern I.ake Ontario.M.S. thesis, SUNY College of EnvironmentalScience and Forestry, Syracuse, NY,

Barton, D.R. 1986. Nearshore benthic invertebrates of

the Ontario waters of Lake Ontario. J. Great

Lakes Res, 12:270-280.

Barton, D.R., and Hynes. H.B.N. 1978. Wave-a!nemacrnbenthos of the exposed Canadian shores ofthe St, Lawrence Great Lakes. J. Great Lakes

Res, 4:27%5.

Cook, D.G., and johnson, M.C, 1974. Benthic

invertebrates of the St. I.awrence-Great I.akes. J.

Fish, Res. Board Can. 31:763-782.

Dermott. R., Mitdtell, j., Murray, l�and I'ear. 1'., 1993.Biomass and production of zebra mussels Dreissena polymorpha! in shallow waters ofnortheastern Lake Ixte, ln Zebra Mnssefs:

Biology, Intpacts. and Control. 'I;I. Nalepa andD.W, Schloesser IMs.!. pp. 399-413. LewisPublishers, Boca Raton, 11 .

Griffiths. R.W. l993. Fffec s of zebra tnussels

Dreissena poiymr>rpha! on the benthic fauna oll.ake St. Clair. In Zebra itfttssels: Biology,&tpacts, and Crmtro , 'I'.I'. Nalepa. and D.W.Schktesser IAs.!, pp. 41%437, Lewis Publishers,Boca Ralon. Fl...

Johnson, M.G, and McNeil. !.C. 19tt6. Changes inabundance and species ct»nposition in benthictnacntinvertebrate communities of the Bay ofQuintc, 1966-1984. In Proj ect gninte:point-source phosphorotts control and ecraystemresponse t'n the Bav of 0tantr', Lake Ontario, C.K.Mfnns, D.A. Hurley and K.H. Nicholls Ms.!, pp.177-189. Can, Spec. I'ubl, I'tsh. Aquat. Sci. 86,

Kovaiak. W.P. 1989. I.ife history and biology of thezebra mussel tDreisseno polvmorplia!,Engineering Research Report 89A90-3. 7 p, 'Obtained from NV Sea Grant Zebra Mussel

Clearing House, SUNY College at Brockport,NY!.

Mackle. G.l., 1991, Biology of the exotic zebra mussd,Dreissena polymorpha, in reiation to nativebivalves and its potential impact in Lake St, Qair.Hyd robiologia 219:~51-268.

Makarewicz. J.C. 1989. Chetnical analysis of walerfrom Buttonwood, Larkin. Round Pnnd and

Nottftrup Creeks, l~ Ontario basin wes , May1987-May 1988. Monroe County Department ot

Heahh. Rochester. NY.

Mazumder, A. 1990. Ripple effects: how lake dwellerscontrol the temperature and clarity of theirenvironinent. New York, NY, '11te Sciences, NewYork Academy of Sciences, Nov,/Dec, pp. 3942,

Miller, S.J. 1994. An analysis of factors potentiallylimiting the abundance of the zebra mussel Dreissena prrlymorpha! in Salmon Creek,Monroe County, New York. M.S. thesis. SUNYCollege at Brockport Brockport, NY.

Miller, S j., and Haynes, J.M. 1997. Factors liinitingcolonization of western New York creeks by thezebra mussel Dreissena polymorpha!. J.Freshwater Ecol. In press.

Morton, B, 197 I. Studies on the biology of Dreissenapolymorpha PaII. V. Some aspects of Alter feedingand the effect ot micro-organisms upon the rateof filtration. Proc. Matacological Soc. London39: 289-301,

O' Neill, C.R,. Jr,. and MacNeilL D,B. 1991, 11te

zebra mussel Dreissena pnlymorpha!l: anunwelcome North American invader. Coastal

Resource Fact Sheet. NY Sea Grant. SUNY

College at Brockport. Brockport, NY,Smirnova, N,l �and Vinogradov, G.A. 1990. Biology

and ecology of Dreissena polymorpha from theLunipean USSR, Presented at the workshop onIntrttduced Species in the Great Lakes: Ecologyand Managment. Saginaw, Ml. 26-28 Sept.

Sprung, M. 1993, The other life: an account ofpresent knowledge of the larval phase ofDreissena palytnorpha. pp. 39-53. In ZebraMasselsr Biology, Impact.s, and Conrrol, T,F,Nalepa and D,W. Schloesser Eds.!. LewisPublishers, Boca Raton, FL,

Sprung, M., and Rose, U, 1988. Influence of foodsize and food tluantfty of the feeding of the musselDreissena polOvnorpha. Oecologia 77:526-632.

Stewarl, T.W. 1993. Benthic macroinvertebrate

community changes following zebra musselcoloruzation of southwestern I~ Ontario, M.S,

thesis. SUNY College at Brockport, Brockport,NY.

Stewart, T,W., and Haynes, J.M. l994. Benthictnacroinv~brate communities of southwestern

Lake Ontario following invasion of Dreissena. J.Great Lakes Res. 19�!:479-493.

Ten Winkel, M. F H., and Davids, C. 1982. Foodselectio~ by Dreissena polymorpha Pallas Mollusca Bivalvia!, Freshwater Biology12:553-558

7~bra hf»»»»»L» a»»d Re»»»bi» hr»»»'mi»»v~rrrbrar» Cci»»»»»»»»»»i»»r» of Sv»»»b» @stem l~ i»»»»»»»'n»»»»d.'»eler»ed 'I'rib»»»»»ri».» U»»»~~»» d Re»»»b»?

Vanderploeg, H,A,. l.iehig, j.R�and Cook, A.A.1996. L»valuation of different phytoplanktonforsupporting development of zebra mussel larvae Dreissena polymorpha!: the importance of size«nd polyunsaturated fatty acid content. J. Greathtkes Res. 22 36-45',

Wright, l!.A., Setjher-Hamilton, E.M,, Magee, J.A�and Harvey, H,R. 1996, Laboratory culture ofzebra �7reissena po ymorpha! and quagga D,btsgensis! mussel larvae using estuarine algae. 1,Great Lakes Res. 22:46-54.

Sandr« tVt Krypr<rr. lr<nrnat k Busiahn, Jerr< httcCt«i<<<<nd liard Jut<<<<un

regarding the need for control as welt «s the potentialsuccess of control alternatives.

To make these assessmenls and predictions, itseems clear that managers need inlormation regardingthe ecological conditions prior to an invasion, includingspecies composition and abundance, interactionsbetween species, and habitat availability, Further,inanagers need to gain an understanding <if the biologyand ecology of the Introduced species and its potentialmechanisms of dispersal, Infonnalion regarding thenew organism's role in its native walers or other areasof introduction contributes significantly to thcdecision-making process. However. pre-invasioninformation including investigations of the communityas a whole i.e, all tmphic levels! is often sparse orIntxunplete,

Thc need for surveillance programs is emphasiaedby lhe intrOduCtiOn ot' nOnindigen<iuS Species,Surveillance programs provide inanagers with the<ipportuntty t<i i! identify net<ly estctblishe<ip<>ptdutions < rarfv, 2! truck nr drtect range expansions,AI estinutte potential inipd<.ts of intrnductinns or rrn<geexpansions by gathering brt.reline data nn pre-existingpopukstions and ltctbitat, and 4! evah<ate contro! orniunagernent strategies. 'Ihe Infortnatt<!n that can beobtained through effective surveillance programs maycontribute signiiicantly to lhe decision-making processregarding the rixk Of further eXpansinn «nd impaetS lonative fauna, as weII «s the need for control, or thecontinuatlon <if conuol implementation.

'I1te <ircat I~s Ruf't'e Surveillance I'nigratit lheProgratn! exemplities h<iw such a program can bec<induCted etteettvely. 'Iiie I'rOgraiii proVldeS a mOdelillustrating h<iw managentenl agencies can respondefieeltVely lO SurveillanCe needh t<tr nOnindigenousspecies introductions. 11ie program has played andc<>ntlnues lo play a critical r<ile in managementdecisions.

BACKGROUND

The ruffe Gvrnnncrph<zhca <rrnuu<! is a smallpercid tish thottght to have, been intr<xtuced into tl}e Ireat lakes !n the early lo mid I98 !» via ballast waterdiSCharge fr<mt tranx-Atlantic Shipping, Il was firStc<illected and identified in I 9tt7 in fish c«Iieet ions frr>mthe Sl. Exiuis River, the westernmost tributary of I akeSuperior, by Wisconsin Department <if NaturalRes<iurces Pratt et al. 1992!. Re-exatnination ofIchthyoplankton satnples collected in 1986 csinfirmedtheir earliest known presence in the river Simon andVondruska 1991. Pratt et ai. 1992!. Since then, ruffepOpulatiOnS have COnlinued tO incmaae in abundanceand distribution. expanding their range along thetuwthwestern shoreline of Lake Superior, I n 1991, ruffewere collected in Thunder Hay, >ntario. likelytransported there in lite ballaSt waler Qt shtps departing

lhc St. Louis River f Busiahn 1997!. By 1993, ruffe hadexpanded as lar east as lhe Bad River, WiSCOnain,approximately l S6 km 97 mi! from the St. Louis River Slade et ai. I994!. In I994, ruffe continued theireastward expansion. being collected in the OntonagonRiver, Michigan, approximately 3 N km I86 mi! eastof the St. Louis River Slade et ctl. 1995!. In 199',ruffe were collected for the first time outside of LakeSuperior at lhe mouth of the Thunder Bay River, LakeHuron near Alpena. Michigan Kindt et ai. 1996! T'igure I!. This expansion inarked a critical turningpoint in lhe management or control ot ruffe. in the Treat IMes.

The importance of and need for consistentsurveillance was recognirnl carly in the history of therufle invasion. In 1992, a Ruffe Control Committee the Coininit ee! was convened hy thc national AquaticNuisance Species 'I'ask Force. I'he Committee wascharged lo develop and refine a control program inaccordance with ihe Nonindigenous Aquatic Nuisancei'revention and Control Act of 199 ! P.L. IOI-6'36! tliatminnuiaes lhe risk of harm to the environment and toihe public heahh and welfare Busiahn and McClain1995!. In developing their plan for control, thei<np<irtance nf surveillance became nore apparent as ameans <>f early detection to design and target areas forc<muol as well as lo evaluate proposed control efforts.

Surveillance was identitied as one of the eighlprimary objectives of the Ruffe Control Program. liteohjecove specitically required a. coordinated programthat would successfully identify newly establishedpopulations of rutTe. This was distinguished within theRuffe Contr<il Program from eftorts to investigateeatabliShed pOpulatiOnS Of ruffe and lhe subsequentchanges in ecosystem dynamics following theirsuccessful establishment.

The kuffe Control Program also identifies theU.S. E'ish and WiMlife Service the Service! and theOntario Ministry of Natural Resources OMNR! as thelead agencies cotxdinatlng surveillance efforts,

RUFFE SURVEILLANCE PROGRAM

The Ashland l=ishery Resources Office is the mainconlact for all ruiTe activities conducted by the Serviceand has led surveillance efforts in the upper GreatLakes, including Lakes Superior, Michigan, andHuron, since 1992. The collection of ruffe near Alpena.Michigan, in Lake Huron in l995 initiated theinvolvement of the Service's Alpena Rshery ResourcesOflice. Since 1996, surveys in Lake Huron andnorthern Lake Micliigan have been conducted hy theAlpena Fisheries Resources Office. Surveillanceefforts on the lower hereat I Mes were initiated in I 993by the Service's Lower Great Lakes I tshery ResourcesAlice. And finally, Ontario's program, initiated in1991, is led by the Lake Superior Management Umt

Rurveillance jor Ruffe in the ireal LakesAn 02vennen'

Sarcdro At. Keppm'r. Aamas k Bus&Ckn. Jerry htc Claimand Cir>rd Jnfuac<at

Fleatl Surveys

Fgete 2. Zacalioee SNrviyef fm Rirfri ie the Upper Grief Baker

in Thunder Bay, Ontario.The current Program impleinented by both

agencies consis1s of three components: iield surveys, amail survey, and public ed'>tlon 1his report willprovide a brief overview of each component and howthey have contributed to the overall success of theProgram.

The primary objective of the field surveycOmponent is to locate new populations of ruff» anddescribe their age/size composition, 'lite secondobjective is to describe the fish cxnnmunity at eachlocation surveyed. 'Ihe field survey component, ifconducted effectively, can provide managers withInforntation towards early detuWon. range expansion,pre-existing populations, and controI evaluation.

Field surveys for ruffe throughout the Great I.akestarget estuaries, hays, river mouths, and waterways onthe periphery of the rui'fe's range and in or nearshipping ports where rufle coukl potentially coloniz»through Intm- or intra-lake shipping activiUes. Most ofthe sampling targets the deepest habitat available at anygiven site, including natural IMiles or channels in riversand estuaries or in lhe dredged shipping channels. 1hcprimary means ot fish coHection is Ixittom trawling;however, elec~fishing, setnes, gill-eas, fykc n«ts. andrnodidled windemere traps are also used, Liach surveysite is visited two to three times between May andCXlober based on habitat suitability and distance tromthe periphxy ot' the known rang».

Since field surveys were iniiiatcd in 1992 hy theAsh}and I'ishcry Res[iufc»N !IHcx.', tile numb»r and

location of survey sites has changed in respons» toexpanding rufle populations. Figure 2 represents acomprehensive overview of all the sites surveyed in theupper Great Lakes. 1992 - 1996. Surveillance at ail ofthese sites, with one exception, was being conductedby the Ashland I ishery Rcs<iwces Office, The oneexception is the site in Thunder Bay, Ontario. TrawlingeAort there is led hy the OMNR As mentionedprev}otLsly, the Alpena Fishery Resources Office is nowparticipating in thc. Program, leading surveillanceeliorts in Lake Huron and northern Lake Michigan.Surveillance in Lakes Foie and Ontario is conducted bythe Lower Great Iwkes Fishery Resources Office,Seven sites on Lake Fme are surveyed, and one site onI.ake Ontario Figure 3!. Surveys in the lower lakestarget areas where ruffe may potentially coloruzethrough inter-lake ballast transfers.

Sampling procedures include measuringenvironmental and water quality parameters, such aswater temperature, dissolved oxygen levels, depth, andSccchi transparency, prior to each trawl. The averagedepth of lhe trawled area, average tow speed, and totaltiine is reixmled for each tow, All fish collected areidentified, counted, and measured to the nearest mm�1 !. When more than SU individuals of any singlespecies are collected in a single tow, a random selectionof 50 individuals are ineasured, providing an adequatesample size to infer size composition of the totalnumber, I"ish that can not be identified in the field,such as small juveniles, are preserved and identified inthe lab. Any ruffe that are collected are measured,placed in zip-lock bags and frozen for later analysis.Agc determination of ruffe is determined in thelaboratory by examining the second dorsal spine.

Sarveiliance for R!e in ttre Great LakesAn OrerrreIV

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! 2 I. Meuraee Fvver2. sanrtuatrr nag3. Curate!us Rprera, au iabuia ~5. CarrneaLA Hadpar6. Erer Herbar7. Bueeta uerirar8. Geneaee Rarer

o6

ileited States

Fit,*«re S. LOealiOttS Surveyed fur Ruffe its tha Lsrrvte Greet Lakes.

ELs � K~axld srL~SMT - Rarrraw SasltTAP - Trpar-prr+

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4. %sue C«teh per sSSSit ~art ~hhta»NSte tessS4«gj pr th«»aaN esmsprosssly eep8eetest slpeei«tt isa the BeefjfiV«V, f992-19PPS. 1Veree letter aQi»en«ti«tnt p» eoa«I»aota a«uses are Stseaf t» ~ spaaeies o« th«x-SRsis. 7hea«1688iOSt Of sai+c iS iwd'iesS'6af ky kksek htAFL

With approximately 50 sites surveyed annuaHy,reporting and analyzing results can become exhaustive,An annual report, summarizing the expansion of ruffeconfirmed that year, as well as comiuon speciescollected, has been prepared and distributed since 1992 S]ade and Kiadt 1992; Slade et aL 1994; Slade er aL1995; Kindt et aL 1996; Czypinski er al, 1997!. Thereport provides an extensive table identifying thenumber and species of every fish collected, Detailedinformation regarding hsh collected at each of flic sitesis found in the individual reports and will not bepresented within the sex!pe of this report, Severalsurvey locations from the upper lakes that have beenimportant in the history of the ruffc invasion arepresented in this paper, as an cxaniple of how managersmight use this information, especially when exananingfish composition prior to or early in the invasion. Sincebottoin trawling is thc primary method of collection, allof the data presented was selected from trawl efforts.

%be Bad River in western Lake Superior has bensampled annually since the program was initiated in1992 Figure 1!, Ruffe were first collected there ia1993, marking the extent of its eastward expansionthrough that year Figure 4!. However; since ollly asmall number of ruffe have been collected at the sitecadi year, totaling only 13 ruffe since 199%, fhe BadRiver continues to be sampled as part of the Ptogtam.

Surveillance has also been coaducted in theOntonagon River, Lake Superior, since 1992 I igure1!. However, ruffe were nN collected there until 1994 Figurc 5!. 'Ious fmdmg, together with the coBectionof ruffe in the Black River, Lake Superior, the sameyear, marked the first collections of ruffe in Michigan

%bc single ruffe collected in the OntonagonRiver ~ the farthest range expansion documentedis a single year. ln addition, the expansion occurredOVer a gel~hphiC area Of Lake SuperiOr's SOuthernsborNne possessing some of the most unfa~ ruKe

sendru td. Keppncr. Drontas k Busiahn, Jrrrr MrCluinund Cinrd !ch'an

oG

199419931992

Pjgnre S. hfean crate+ per sr»it effnrt Affrsklnrinnte trsttrling! far the mast ctn»tno»ly cogscted species in theOntn»age» River, 19M-l t95. Three letter abbrevustiens fm can»»an names are used ta ~ sirecies o» the<~is. 7%e caikction af ruffe is ntdicated by bbrck bars,

~ RuA'e ES 'stostomtdae

25

01991 1992 1993 19"4 199S 1 996

Year

Fig»re 6, @fear csttck trer n»it effect +arktnsi»nte ssrw5ag! fer tbe »test can»nn»ty cagscted spacies in T n»derBey, O~ Htw-19s�. Rnffs bkrck kerr! teem detected in s»reeiQance ~arts 19N, 19tsd, n»d 10Wi,

RUF- RulTeTRP - Trout-perch

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Sttrvetltanee for RtttJe in the Great LakesA» Overview

Mail Survey

CONCLUSION

Z3

habitat, It had previously been hoped that theunsuitable habitat might provide a natural barrierslowing expansion, Although only one other ruffe wascollected in 1995 surveys, the sighting causes additionalconcerns because of its close proximity to thc entranceof the Keweenaw Waterway, the pathway to easternLake Superior.

Surveillance efforts were initiated in Thunder Bay,Ontario, by the OMNR in 1991 to verify the presenceof ruffe in the harbor following the capture andreporting of a single ruffe by an angler Figure I!.Although ruffe were confirmed in trawl catches in1991, they were not caught again in the Bay area until1994, and then again in 1996 Figure 6!. Six ruffewere collected in 1996, amounting to a total of IS ruffecollected from Thunder Bay. The need to continuesurveillance seems apparent as numbers have reinainedvery low over the six years since they were first found.

To increase the comprehensiveness of theProgram, both agencies recoginzed the role that pubhcand pri vate agencies, organizations, or individuals couldplay in surveillance efforts. In 1994, the OMNRinitiated a program expanding its surveillancecapabilities. A voluntary program was establishedtargeting agencies. organizations, or individuals. thatroutinely collect or handle Great Lakes Ash or thatexpect to conduct fishery surveys in the Great Lakes,In 1995, the Service initiated a similar program, leadby the Ashland Fishery Resources Office.

Each year potential participants are contactedtwice through the mail. The first mailing is aninformational packet that includes educational materialssuch as brochures, painphlets, and identification cardsregarding the rut'fe. An explanation of the program, therole of participants in surveillance and the importanceof documenting range expansions is included. lire firstmailing also encourages participants to report anypotential ruffe sightings immediately to the Service orto OMNR. In the faII, following the field season, afollow-up questionnaire is mailed encouragingparticipants to provide information regarding theirsampling efforts and fish collection. The informationrequested is simple, including sampling location,collection method/gear, a general approximation of the-nurnher of fish handled, and the presence or absenceof ruffe.

To provide- some insight to the scope of thiscomponent, in 1995 the Asldand Fishery RescaircesOffice sent out 439 packets to agencies and tribalcommercial fishermen in the upper lakes, Resyoeserates from both Canadian and U.S. participants havebeen low. However, even with low resrxinse ries,overall surveillance within the Great Lakes is incn~Asubstantially through this initiative. For example,

Canadian responses in 1996 expanded reporting on thepresence or absence of ruffe to Canadian waters of each.of the Great Lakes Figure 7!, Many of the sites areincluded in other sampling efforts condudcd by OMNRor the Canadian Department of Fisheries and Oceans,such as sea lamprey assessments or control treatmentassessments, annual standard nearshore and offshoreassessments, and aeel surveys, Industries have beencooperative as weII, providing Information on speciescollected on intake screens, trash racks, etc,

lite public has historically played an importantrole in nonindigenous species prevention activities,especially surveillance. An informed public is critic&to the success of nonindigenous species activities ingeneral. More specifically, surveillance programs maybe enhanced significantly through the participation ofpublic water users. In several cases, recreational anglerswere the first to report the presence of ruffe in newlocations, findings that were then verified bysurveillance crews. A public that is aware of newlyintroduced species, pathways of intrrxiuction. and whatto do if they think they have caught a potentialcandidate, will contribute to surveillance efforts as wellas to control or prevention efforts minimizing the riskof further introductions or range expansions. Educationinitiatives are the primary tools managers possess toreach public water users.

Working with Sea Grant agencies in the GreatLakes states, both the Service and OMNR havedeveloped or ~ in the development of variouseducational materials targeting anglers, bait deakrs andharvesters, rnariria owners, etc, Posters, brochures, andpamphlets have been distributed to anglers and anglinggroups, mafInas, bait shops, and public access sitesthroughout the Great I~. Development of the RuffeIVATCH identification card was likely one of the mostsuccessful education initiatives, This wallet-sized cardwas designed so that anglers could easily store them intackle boxes. with other fishing gear, or with theirlicenses. It was produced in a number ot formatscreating regitutal cards. EaLvh card includes regionalcontact agencies, phone numbers for reporting potentialsightings, and iirformation regarding what to do withthe candidate fish. &e need for strong educationprograms and the -support anglers may provide tnsurveillance has been proven. as so often anglers arethe first to report sightings.

Ihe Great Lakes Ruffe Surveillance Programprovides resource managers with a model response tothe introduction of nonindigenous species, ltexemplifies an effective means to assist managers in I!

Sandra IH. Keppner. 77vmvr~ R. Bu~iahn, Jerry hfcClainand iard Jrduxson

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identifying newly established populations early, 2!detecting range expansion, 3! estimating potentialimpacts of introductions nr range expansions hygathering baseline data, and 4! evaluating controlor rnanagernent strategies. As shown through thisoverview, the effectiveness and scope of surveillanceprograms can be enhanced signitlcantly by conductinga multi-agency program consisting of components thatbroaden surveillance capabilities. This Program,conducted by the Service and the OMNR consists ofthree components: field surveys, a mail survey, andpublic education. The implementation of thesecomponents by both agencies has expanded surveillanceefforts to U.S. and Canadian waters in all five of theGreat Lakes.

The field survey component assists managers toachieve all four of the above objectives. Field surveysconducted along the periphery of the ruffe's establishedrange as well as in areas where ruffe are likely tobecome established, are apparently capable of detectingruffe, even at relatively low population densities. Thisis likely due to the iuffe's high selecfi vity for favorablehabitat at low densities. This ability is critical to earlydetection. However, inanagers must accept thelimitations of sampling gear, realizing that absolutecertainty can not be achieved ie., just because ruffewere not collected in a given area, does not mean thatthey are not there!.

The detection of new populations or rangeexpansions inherently provides managers with amechanism to evaluate control ineasures. For example,only two range expansions of ruffe within the GreatLakes are believed to have been associated withsomething other than naturA movement, Infra- andinter-lake ballast transfers are likely responsible forintroducing ruffe to Thunder Bay, Ontario. and Alpena,Michigan. However, only the Alpena, Michigan,sighting was documented following the implementationof the Great Lakes Maritime Industry Voluntary BallastWater Management Plan for the Control of Ruffe inLake Superior Ports in 1993 ln l995, when fieldsurvey crews first found ruffe in Alpena, Michigan, agedetermination indicated that ruffe had likely beenfntnxlBced lilto the area prior to the llnplenientatioii ofthe ballast water ~ strategy,

The field survey component also ptovides- anannual, consistent sampling progr trn, from which tishspecies composition and atmndance, habitat and waterquality parameters can be estimated. 1Itis providesresource managers with information regart5ag thebenthic Ash cotnmunity and habitat in areas wherepreviously little to rio inforination may ha've existedObtaining this type of information prior fo theestablishment of ruffe wiII assist managers withestimating potential impact to the system fotlostnrtgtitetr tttvasion.

The mail survey and puhhc ethtcation ootttlxanents

ot the Program broaden surveillance capabilities. Theamount of staff and time that can be dedicated to artyfisheries prograin is lhnited. By educating other waterusers, surveillance is expanded beyond those-limitations. Mail surveys target agencies,organizations, and individuals that routinely collectGreat I~s fish or that expect to conduct fisherysurveys in the Great Lakes. This program includesgovernment agencies, academic researchers,coinmercfal fishermen, industries that draw water, etc.ln addition, the public education component targets aBpotential water users. The value of public educa5anhas been proven, as anglers are often the first to reportnew sightings of nonindigenous species.

This Program exempli fies a pro-activemanagement approach to nonindigenous sees.

'Ihe information obtained through the Program hasplayed and will continue to play a significant tule inpolicy- or decision-making processes.

ACKNOWLEDGMENTS

Ihe authors would like to thank Gary Czypinskifor providing data used in preparing graphs for thisdocument and Amy Benson of the U.S. GeologicatSurvey - Biological Resources Division for ass~in providing distribution and survey site maps.authors are grateful to all staff and volunteers who haveassisted with conducting field surveys, fishidentitlcafion, and data entry, In addition, the authotrswould like to thank aII those who have respots9ed tothe mail surveys and anglers who have reportrxf thecollection of potential nonindigenous species, includingthe ruffe.

Busiahn, T,R. I997. Ruffe control: A case ~ of anaquatic rmisance species crmtrol program. InZebra assets and Aquatic Naissance Specie.~.F.M, D'Itxi ed�Ann Arbor Press, Inc., Chelsea.MI, pp 69-86.

Busiahn, T.R, and J.R, McClain. 1995, StanLs andcontrol of rufTe Gymttocephalus cernuus! in LakeSuperior and potential for range expansion. In TheLake Heran Ecosystem, Ecology, Fr'sheries andManagement. M Munawar, T. Edsall, and j. Leacheds., SP8 Academic Publishing, Amsterdam, TluteNethedands, pp 461-470.

Cziyisski, G. D., 'G. Johnson, A.K Hintz, and S.MKepfmer. I997. Surveillance for Ruffe in the GreatLakes, 1996. U.S. Fish and %'ildlife Service,Ashland Fishery Resources Office, Ashland, VA.

Dertncat, R l997, Changing amphipod comnnuuty inthe lower Great l~ following the introduction

,'indra M Keppner, 7homas R. Bnsinhn, Jerry hf< Cruinond Cmrd Johnson

of Ponto-Caspian species, Seventh !nternationa!/<bra Mussel and Aquatic Nuisance SpeciesConference Program and Abstracts, January 21!-3!,1997, New Orleans, LA. pp 4t!.

Kindt, K,. S.M, Keppner, and l. Johnson, 1996,Surveillance for Ruffe in the !reat Lakes, 1995.U.S. Fish and Wi!d!!fe Service. Ash!and FisheryResources Office, Ash!and, WI,

Mil!s, f..L.. J.H. Leach, J,T, Carlton, and C.L Scum.1993. f:rot!c spedes in the sreat Lakes: A historyof biotic crises and anthropogen!c intrtx!uctions.Journal of Great Lakes Research 19 l!:1-54.

Prot, D,M,, W,H. 8!ust, and J.H. Se!geby, 1992. Ruffe,Gynrnocephaius cernure", New!y introduced inNorth America. Canadian Journal of Fisheries andAquatic Sciences 49:! 6! 6-! 6! 8,

Simon, T.P, and J.T, Vondruska, 1991. Larva'1

!den0timtion of the ruffe, Gyrnnocephalus rernuus Linnaeus! Pere!dae: Percin!!, in the St, LouisRiver fatuary, Lake Superior drainage basin,Minnesota. Canadian Journal of Zoology6!r. 436-&2,

Slade, J. and K. Kindt. 1992. Surveillance for Ruffe inthe Upper Great f~s, 1992. U.S. Fish andWildlife Service, Ashland Fishery ResourcesONce, Ashland, Wl.

Sfade, J.W., S.M. PM, and W.R. MacCal!um, 1994.SurveiHaiLe for Ruffe in the !rest Lakes, 1993.U.S. fish and Wi!d!!fe Serviu., Ash!and FisheryResources Office, Ash!an, W!.

S!ade, J.W., S.M, Pail, and W,R. MacCa!!um. 1995.

SurveH!ance for RuAe in the lreat Lakes, 1994.U,S. l'ish and Wildlife Service, Ashland FisheryResources Oft!ce, Ashland, Wl,

Zaranko, fX 1996. New exotic found in f~ Ontar!o,

jreat Lakes Commission. Advisor, 9�!'.7.

Roatd Gob'res: CvberjBA of he 7hird Mllessiam

Great Lakes Research Review

VoL 3, N0, 1, Aprii 1997

Round Gobies: Cyberfish of the 'Fhird Millennium

David J. Jude, Research ScientistCenter for Great Lakes and Aquatic Sciences2200 Bonisteel Blvd.

University of MichiganAnn Arbor, MI 48109-2099

djudeOunuch.edu

&TRODUCTTON

Roaad &br~iyta&s

rabeaase gabyPpgv~~~ c ~us

LIFE H1STGRY

The proMem of transport of non-indigenousspecies from one place to another transcendsboundaries, jurisdictions, and most of the efforts ofhumans to contain them, A recent study by Mills etal. �995! lists 139 species that have made a substantialimpact on Great Lakes ecosystcms and they includeorganistns from bacteria, such as furunculosis, throughpurple loosestrife Lythrum salicaria! and Eurasianwatermilfoil Myriophyilurn spicatum!, to Ash. Thetransfer of these organisms was brought dramaticallyto the attention of businesses and the public with thediscovery of zebra mussels Drei ssena poiytnorpha! iu1986 Hebert er ai, 1989! as water intakes becameclogged, power plant pipes became plugged, and boatsand motors became covered with this species. Thehomogenization of our aquatic communities, loss ofbiodiversity, and amalgamation of our gene poolsbecause of the introduction of exotic species is aworldwide problem of which the round goby Neogobious melanastomus! is just another symptom.'ihe round goby along with its smaD cousin, thetubenose goby Proterorhinas rttarrrtaratus!, are ourlatest uninvited piscine immigrants joining Great Lakesfish communities. These fish are cyberfish, becausethey carne from a distant universe and have the unusualability to attain high abundances in optimal rockysubstrate areas in thc face of native fish communitiesand they also are able to disperse ralndly using GreatIlies freighters as transport vectors.

The tubenose goby is a member of the familyA!biidae, whose members possess a unique fusedpelvic fin suctorial disk!, this chanacker can be usedby the discerning individual to separate these Ash frotnall other fishes in the Carat Lakes basin Rg. 1!. ltalso has elongated nostrils, which are characteristic ofthis specieS, The tubCnOSC goby is a Small 5ah rcaehing

jrjjpgpp J Dnnisgr af the mand geby Weagebatsjasbsnastoasas! sbstwastt the fasted pebie JVa atar tkettatsnt bbsck spnt, asat the tabeaose goby Aeterar]Itin~tasreasssttsas! sIsowastr tbe protniaeat aestrih.

lengths up to 11 ! inm � in!, lives to about5 years,and once thc males spawn they dic. Iliey defend nestsunder rocks, shells, higs, and produce young thatresemble aduhs Miller 1984h!, Ate diet of sn>aJIgobies consists of aquatic insects and benthiczooplankton Jude er aL 1995!; sonic specimens wecollected «tc round goby fry in the St. Clair River Jude, unpublished data!. '%e tubenose goby has onlybeen found in the St. Clair River, Lake St. Clair, andwithin the liras I km ol' thc Detroit River. Ii has notspread as far or «s fast as the round goby, Populationabundances would be considered low and they appearto have had negligible impar% on fish communities todate. ironically, because of habitat destruction, thetubenose goby is endangered in its native habitat ofthe Black and Caspian Seas ln Russia Lelek 1989!,

'ihe round goby also has the characteristic fusedpelvic. fins, elongattxi dorsaJ and anal fins like thetubenose goby. and a unique black spot on the dorsalfrn. interestingly, a large percentage of the roundgobies in 1~ V>e do not have this black spot, whichas far as we can tell, has not been observed in Eunipe.

' he round goby attains a rriuch larger size, up io 2S mrn or IO in, and lives I'or vp to 5 years Berg 1949!Alter attaining a large sia., males spawn once, thernorrnaily die. flic key to why certain males will defenca nest and others do not is unknown. It may be relaterto finding a suitable site, attaining a large size, oiaggressiveness. Round gobies are known io producrseveral vocalizations, including one that attract.females to nest sites and one that intimidates male; Protasov et aL 196~!. Females, however, do not dirafter spawning, and can spawn up to six times dur|nJthe spring and summer, every 20 days conveying;great competitive advantage over native species thausually spawn once during spring. MaJes turn coablack and defend nests made under rocks, in beer cansand in hollowed out logs I.arge eggs fecundity i.around 5, XX! eggsffemale - Miller 1984a! are depositeron the undersides ol these structures; several female.can deposit distinctive, cone-shaped eggs at one sitr Miller I984b!. Round goby larvae also resemblradults at hatching and appear to be benthic, sinu the!have no swini Madder. 'Ihe round goby is an importan

L Carre¹t ksbibatiaa of le ~tt¹d gaby i¹ tJ¹ 6ru¹r hiker +dock deb!, i¹cirdi¹g e¹rr ter,ord t¹ ce¹trrrfNkkiles i¹ the $kie¹etsee Jfiaer. lhc trrJN.¹ase goby ir femef i¹ Se St. CJNfr ¹¹rf Deceit Piers ¹¹tf laht SLCkw.

component of the commercial catch and is eatenregularly in Europe, but has declined precipitously inrecent years because of'degradation of habitat Moyleand Cech 1988!,

The round goby is robust, aggressive, and canwithstand very low levels of dissolved oxygen Jude,unlxrblished data! and apparently defends vigorouslythe type of rocky and cobble habitat it prefers to theexclusion of some native species. Small round gobieswere most conunon in the nearshore rocky riprap area.but eggs were trawled from deeper water, Roundgobies were also found in beach areas withpredominantly sandy substrate, but numbers werereduced in these areas. They were most prominent indepths oi' 3-S m, but were found all the way out to 10m in the channel of the St. Clair River Jude er aL1995!, Tltere appeared to be a direct relationshipbetween length of round goby and depth where fishwere found. Round gobies are adapted to be primarilymollusk eaters, to which their well developed,rnolariform teeth attest. The studies we have rxinductedso far indicate that at smaH sizes they eat benthos. andbenthic moplankton while an increasing proportion oftheir diet as they grow older is zebra mussels,fingernail clams, and snails. Most zebra mussels eatenwere 2-12 mm in length Jude et aL 1995!, Ghedottiet aL �995! has recorded the consumption of over 100zebra mussels per day in laboratory studies. Stomachsfrom large individuals we examined generallycontained 10-12 large zebra mussels from 6-12 mm.

Round gobies appear to be adapted to warmtemperatures and growth of our fish is much slowerand maximum lengths are smaller than specimens fromthe Black and Caspian Seas. In addioon, fish fromLake Erie, which is presumably much more productiveand warmer than Lake Michigan or the St. Clair Rivergrew the fastest among Great Lakes mund gobies weexamined Jude er aL unpublished data!, Dougherty ercrL �995! have found that Great Lakes specimens wesupplied from the St. Clair River, which hadmitochondrial DNA examined were not derived fromnative populations he sampled fmm the B!ack Sea nearVarna, Bulgaria. A hybrid species between N,rnelanosromus and jfuviaiifis has been documented inFurope {Pinchuk 1970!.

First discovered in 1999 in the St. Clair River Jude er aL 1992!, the tound goby htts now spreadthroughout the St. Clair River system into Lake St.Clair, the head of the Detroit River, Lake Erie,scatthern Lake Michigan, southern Lake Huron, Lake.Superior, and there are recettt ~ af their captutein Lake Ontario, cotnph@ttg their dispersal thnoufghorttthe five Great Lakes ln 5 yeats, dispersal ahnost asfast as the zebra mussel ~ig. 2!. It took the alewife

A toro pseudoharengus! and sea lamprey Petrcrmyronmcrrinrcs! almost 25 years to make it into Lake Superiorafter once reaching i ake Erie Jude attd Leach 1994!.lite early non-indigenous species probably movedfrom lake to lake by swimtning, while round gobiesand ruffe Gymnocephaius cernuus! Pratt er aL 1992!were ballast water transfers and continue to betransferred throughout the Great Lakes by Ihe siemechanism. in addition, there is one known occurrenceof round gobies inland in the Shiawassee River, nearFentou, Michigan Raesly, R�personalcommunication, Frostbmg State University, Frostburg,Maryland!,

RKAL AND POTKNTIAI. IMPACTS

Predation by round gobies ori other fish has onlybeen recorded once, when a 41-rnm adult trout-perch Percopsis crmi scomaycscs! was found inside a 139-mmround goby, Round gobies have been caught byfishermen using minnows; they have killedcohabitating darters Erheosroma! in confined aquaria probably a territorial response!; and are known to eatfish in their native habitat Miller 1986!. %itis opensup another avenue of potential unpact of round gobieson native species, since round gobies can prey on fairlylarge, cohabitating benthic fishes.

Competition for hmited resources at can hfestages may be @>otter intnfmx of interaction tretsneenround gobies and other native fish. Round gobies attainhigh abundances and eat benthic zooplankton andbenthos which is, important food for the young ofcohabitating mottled scMpins Cottus bairdi!, marten,logperch Percina caprodes!, and some minnows Voiropis spp.!, Diet overlap with some of thesespecies is substantial tTmnch, J., D. Jude, and G.Crawford, unpublished diet data!.

Our resetrch in the St Clair lUver has indicatedthat round gobies have seriausly impacted a native,bottom-dweOing species, the mottled sculpin, causinga dramatic decline in their populations fmm when theywere the second- or third-most aburtdant species inprevious studies done in the river. 'Ae remnant of thcsurviving maNed sculpin popahtion was forced intodeeper water, where the round gaby appears to be lessabundanL We hypothesize that the round goby, ber"tuseof dtAerenrces iu the neural canals between these twospedes, does not ixmpM as well with the mottledswlpin in deep, high velacity waters, as it obviouslydoes in ~@allow water jude er rzL 199S!. ln shallowwater, the mechanism of this competitive advantage ofmund gobies over native species appears to be theaggressive nature of the round goby which drivesmottled sculpin from printe feeding, shelter, attdesperjaHy spawning areas. We think that mottledscnlptn spawning has been disrupted causing almosttotal year class failure of the mottl& scwlpin in areas

where round gobies arc abundant. 'Ihis hypothesis issupported hy evidence that shows that round gohieswould drive mottled sculpin from <ate shared shelterin our laboratory aquariunt studies and recent sAudiesby Dubs and Corkum I996!, In addition, field studiesconducted by John Janssen, Iaiyola University, wercinitiated in the Calumet River Harbor «rea in southernl.ake Michigan before round gobics became abundantin that area in I995. It is clear tmm his SCUBAobservation data I Ig. 3! that mottled sculpins sufferedyear clam failure starting in I995 when round gobiesstarted to become common!, since tx! YOY mottledscuipin were obscwcd there despite tlleil' presence InI994, along with observations of gravid females, Inl 996, not only YOY were missing from theage.-groups, siniilar to what happened in I995, butyearlings werc also absent, ln l996. again no YOYmottled sculpin were tound, however, there wereseveral round goby defended nests present in the area.Very tew mottled sculplfls were observed, cxc'ep't lofold adults aplxirently coming in front other areas. 1%ispattern has there fine been repeated in two areas ot highabundance of round gobies.

'I%ere are three possibly damaging scenarios we«re concerned atxxn that may come to pass in thefuture, 'Ibe tlrst of these is fixxi chain bioaccurnula0onof PCBs, Sinix: rzhra mussels are known to accumulatelarge concentrations of PCBs de Kock et al. 1993!, andround gobies eat large numbers ot sabra mussels, andnow aport fish are eating round gobies Jude et al.I99~!. the potential for contamination of imixxtantslxirt I'isll ls of obvious concern.

Secondly, arxither species oi' gaby, the black goby Gnhiws nigt r!. has been dix;unrented in a Netherlandstake to have caused tltc dcnusc ol a species of sculpin,which is a congener of our Great I~kcs deepwatersculpin Vass et al. 197%!, 'lite deepwater sculpin Isvery abundant in tie deep abyss of the upper threeGreat I~i. 'lite IxxcntiaI existsfiir the round gobyto have a negative iinpact on these populations, Theliterature states that round gobies will overwinter inwater up to 6 ! ni deep in thc ltlack Sca Miller 1986!.I eepvater scwlpin usually reside in water %0 m ordeeper. To date we have evidence that in the GreatLakes, round gobies have been tound in 18 m �0 feet!of water in Lake I+le, IS m sO feet! of water in IMeMichigan, and in IO m of water in the St, Clair River.Therefore. the potential definitely exists for this speciesto occupy deeper water and affect deepwater sculpin,either by txlttpeting with them I: or f<xxt Mysis andOipareio! or eating eggs froin their nests. Deepwatertxxtfpin make shallow depressions on the bottom duringwinter, eggs are laid, and then guarded by the male.However, the coMer water there ixnistant 4 C! mayinhihiit round gobies from detrimentally affectingdeepwater scuipin.

Thittl, round gobies are currently confined to the

Great Mu'.s and connecting channe/s except for oneoccurrence in the Shiawassee River in rnid-Michigan.Round gobies have penetrated about 19 km upriver inth» Caluinet River system in southern Lake Michigan.which is about 4g ! km away from the MississippiRiver Steingraeher et aL 1996!. Once they reach theMississippi River or some inland lakes, round gobieswill be exposed to another new ichthyofauna and weknow nothing about those interactions. Their currentability to depress mottled sculpin papulations, a nestguarder, makes us concerned about interactions withvery important native nest guarders, such as thebluegill and large and smallmouth basses.

BALLAST WATER TRANSPORT

There have been a number of ways in whichexotic species have entered the Great Lakes, withballast water discharge, by oceangoing vessels recentlyattaining prontlnence as the leading causes of theseunwanted introductions Mills et rd. 1995, Carlton19M, Moyle 199I!. 'He presence of round gobies inthe St. Clair River is a syinptom of our lack of dealingwith the global translxm of non-indigenous ~les.'lite reCent examples Of rebra rnuasel, ruffe, and thegohies are testimony that we still have not a@tailedthis threat to our aquatic ecosystems. Further evidenceof our lack of control ot this problem is that U.S. CoastGuard mandatory and Canadian voluntary restrictionson iorcign freighters to exchange ballast water withseawater in order lo kiII freshwater organisms beingtranspotted were just beginning at the tiine of most ofthese latest intraductions. Obviously mare must bedone, and there are in fact recent efforts to design apilot filtration apparatus aboard the freighter Algonorthto evaluate the efficacy of this approach of treatingballast water.

Round gobies may be pre-adapted for transport inthc ballast water of transoceanic ships and alsofreighters within the Great Lakes, which is probablyhow they got here in the first place and probably whyround gobies have been able to spread so far so fast.Tlte family Gobiidae is the family with the secondlargest numbn of species of fish, some 2,GOO species,and this indudes many weII-adapted species, such ascaveftsh, which live in complete darkness, nil unlikethe ballast water enviroiunent of a ship. Our new foundgaby guests should not come as a surprise, nor shouMtbe introduction of additional species in this family.There are many incidences oi freighter transpeft ofother species of gobies into other water bodies acrossthe world, including new introductions into Australia,San FrancLam Bay, the Arabian Sea, and recently theround goby has extended its range into the Aral Seaand into the Baltic Sea in the Bay of Gdansk, Poland Moyle and Cech 1988, Hoese 1973, Al-Hassan and

Round Gobirs: Cyberfisk of rke Third hfNennium

10

7

o 6

5 4 3 0 20 30 40 50 60 70 80 90 10025 35 45 55 65 75 65 95

Standard length mm!

F~ ~. ~~ficqecacy ~5aas cf seaNkd se~ Aviv@ 1994-1996. Fisls were abscrrcs1 durum S'CUBAscrcsys ~ ~ siCe im Cal'coact khwhur, seafiscre Icky hfiekigaa, Nerve the pnsgressive loss cf ypcng-cf~yccr cad

%1s cs tumed gehics beeccle c 4aekaet ic 199$.

Miller t9tt6, Miller I9N4b, Skora and Stolarski 1996!.The patterns we have seen in the Great l.akes, rapidexpansion in areas of optimal rocky habitat, have beenrepeated in these environments a» well. So ourexperiences are not unique,

Ittere are many reasons why round gohiescontinue to be carried amund the Great Lakes in ballastwater of ships, f'irst, ships routinely take on largequantities of water, thous@nb of tons. from a place. likethe St. Clair River where round gobies are veryabundant. This water is transported elsewhere anddischarged. lt is no wonder hat the major porls in theGreat Lakes, Duluth Superior, Calumet River, and theGrand River in Lake Erie were sites where they wereinitially dumped aad have subsequently done very well.lhese river mouths and harbor areas have extensiveareas of riprap, sheet pihng, and other structure thatprovides ideal substrate for hiding, feeding on zebramussels, and for reproductive activities, Round gobiesare very cryptic species; they occupy holes. crevices.and cxacks and may have irccupied these places on

ps. They may «tso have tatd eggs on the undersldesof ships or ln suitable holes thereby allowing the eggsto be transpcxtect hing distances before they hatched,

Round gobies have a lateral line system neummav1s in the head region! which is very welladapt for feeding in the dark a<xi is almort uaiqueamong Great }~es species. Studies performed by JohnJanssen on mund gobies have shciwn that round gobiescaa frsxl in complete darkness and can detect prey ata shred' distance than can mottled sculpin, giviag thema eruapetitive advantage in this area as well Jude rtrrl. J99S!, This feature feature. aking with the roundgoby's tolerance for degraded water quality, hasprcibahly pre-adapted round gobies lor transport in shipsand their hallet water.

I'RKDATORS

Predators have shown an interest in round gobiesin thc Yt, Clair River, probably because they are soabundant in that system, prcchtors we found to havepreyed on round gobies included rock Irass ArnhfopNtesrupesrrivj, xmallmouth bass {Nicrnpreru» doforrtieui!,stonecat No urus jlavusJ, tubenose goby, bmwn trout Srrbno rrrrrrrrJ. walleye Sti osredion virreum!, yeHowperch {Perca g4vescerrs!, rainbow smelt Osmerrrsrnordax!. and even mottled sculpin. Cannibalism wasalso common for this species,

REASONS FOR DOMINANCE OFAQUAV1C HASITATS AND CERTA.1N

FKSHES

Round gobies have dominated optimal rockyhabitat areas ia the Great Lakes Jude and DeBoe 1996jbeanie they grow to a larger size than cohabitating

native benthic list!es. like the darters. logperch, andinottled scutpin. In addition, they are aggressive, spawnoften during the warm water months proctucing manycotxrrts some of which are guaranteed to survive!,guard lhe nests insuring high survival of young, andthey can feed in complete darkness. Another reason thatround gohies have been so successtul can be attributedto zebra mussels. lt is known that zebra mussels transferenergy from the pelagic zc!ne water o!lumn! to thebenthic zone Kterks er al. 1996! thmugh their filteringcapabilities, I'ueling a large growth of zebra musseLs atthe expense of zooplankton which would have fed onthe algae and detritus removed by the mussets l!ermotter crt, l 992, Griffiths 1992!. Zebra musseks are not ofteneaten by native tlrsh species French and Love l995!,so they represent a dead end ecologically, However,round gobies greater than IN! mrn feed «lrnostexclusively on zebra mussels with little competition,allowing them to build up large prrpulations, which cancause problems because of sheer numbers alone Judeer ul. 1995!, I-or example, we oAen got over 20f! roundgobies in ] !-min hauls with our 5-rn headrope trawl,and up to 5 N! per haul were coltectixi in Lake Erie. lnaddition, since the invasion of the quagga mussel Drei.rseiia bugensis!, which has a cooler and deeperwater tolerance Rosenberg and Ludyanskiy l994;Spidle er al, t 994!, another source of mussels may beavailable for round gobies in the deeper, soft sedimentareas of the Great Lakes where zebra mussels wereprevented from colonizing because of the lack of hardsubstrate. 1Ms is especially true for Lake Foie undOntario, and may also allow quagga mussels to llourishin Udice Superior, where zebra rnussels have not donevery well

CONCLUSEQNS

Appearance and dispersal of round gobies, whichhave become a permanent member ot Great Lakes fishcommunities, are causes of loss of biodiversity and asymptom of our damaged ecosystems in the GreatLakes, since entry of exotic species are favored whenfish community integrity is severely destabilized. Exoticspecies, including the introduced salmon{Oncarhy~chas spp,! and rainbow �. mykiss! andbrown trout, alewives, rainbow smelt, and the infamoussea lamprey have irrevocably changed ecosystem formand fuactirm in the Great Lakes. The round goby is justanother addition to our growing Bst of exotic speciesof aot only fish, but of other groups, includinglnvertebrtues, weIJ represented by the zebra mussel, andplarrts, iacluding the notcrbms purple looses1rife, whichIs destmying our wetlands. Dtese organtsals arewalking more havoc with ecosystetn ~ than toxicsubstances or nutrients, smce we at least have done,and can contimre to do, sotat~g about controllingthose problems. Once in, most sur~ssM exotic ~establish permanent populatioas which are irrevocably

detrimental to tish cornrriunrty stability and causeserious loss ol irreplaceable genetic nraterial andbiodiversity. Their effects are diflrcult to deal with,comp/ex, and like a broken heart on Valentine's Day,it is something thai we just can'l tax!

LITERATURE CITED

Al-Hassan, L A. J., and P. J. Miller, l987, khirrogobirrsbrrrnrreirs Gohiidae! in lhe Arabian Gul f,Japanese Journal of Ichthyology 33�!;4115~,

Berg, l.. S. 1949. Freshwater fishes ot the USSR andadjacent countries, Vol. 111, 1-2d-vo, AN SSR S]0pp translated by israel I'rogram for ScientilicTranslation, Jerusalem 1965!.

Carlton, J. T. 1985. Transoceanic and interoceanic

dispersal ol coastal marine organisms; the biologyof ballast water. Oceanogr. Mar. Biol. Ann, Rev.23 31'3-371.

deKock, D�W, Chr., and C. T. Bowmer, 1993.Rioaccumulation, biological effects and food chaintransfer of contaminants in the zebra mussel

Dreissena polymorpha!. Chapter 3G, pp, 503-533.In Zebra hfrrssels: Biology, Impact and Control,T. F. Nalepa and D. W, Schioesser eds.!, LewisPublisher/CRC Press, Inc. Boca Raton. FL

Dougherty. J.D., %, S. Moore, and J. L. Ram. 1996.Mitochondrial DNA analysis of round goby Neogobius melanostomus! and tubenose goby Proterorhinus marmoratus! in the Great Lakes.Can. J. Fish. Aquat, Sci. 53:474-480.

Derntott, R., J. Mitchell, l. Murray, and E, Fear, 1992.Biomass and production of zebra mussels Dreissena polymorpha! in shallow waters ofnortheastern Lake Erie. pp. 399-414, ln ZebraMussels; Biology, Impact and Control. T. F.Nalepa and D. W, Schloesser eds.!, l.ewisPublisher/CRC Press, Inc, Boca Raton, FL

Dubs, D. O,I., and L, D. Corkum. 1996, Behavioralinteractions between round gobies Neogobiusmelanostomus! and mottled sculpins Cottusbairdi!. J. Grear Lakes Res. 22:838-844.

French III, J. R. P., and J. G. Love. 1995. Qzelimitation on zebra mussels consumed byfreshwater drum may preclude the effectiveness ofdrum as a biological controRer, FreshwaterEcology 1G�!:379-383.

Ghedotti, M., J. Smilntia, and G. R. StnitIL 1995. Zebramussel predation- by -round gobies in thelaboratory. J. Great Lakes Res. 2I:66S-669.

GrifIiths, R, 1992, Effects of zebra mussels {Dreissenapofyntorpha! on the benthic fauna of Lake St.

Clair. pp. 41%-438. ln Zebra Nussels: Biology.Impact and Control, T. F. Nalepa and D. W.Schloesser leds,!. lewis Publisher/CRC Press, lnc.Boca Raion. I'I..

Hebert, P.�. N�R. Muncaster, «nd 6, 1 .. Mackie, 1989,l..'cnlogical and genetic studies on Oreissenapolymnrpha fPallLs!; a new nrollusc in the GreatLakes. Can. J. Fish, Aquas, Sci. 46;1587-159L

Hoed'!, D. 1. 1973, The intnxtuc<on of the gobiid fishesAcanthogobius flavimanus and Tridentigertrigonocephalrrs into Australia. Kookewong2�!:3-S.

Jud, D. J., and J. I ach. 1993, Chapter 22; Great LakesFisheries, ln I~land Fisheries Afanagement inNorth Anrerican, C. fCohler and %. Hubert, eds.!.American Fisheries Society, Bethe!uia, MD. pp.517-M

Jude, D. J., and S, DeBoe. 1996. Possible impar% ofgobies and other introduced species on habitatrestoration efforts. Can, J. Fish. Aquat. Sci.53 Suppk 1!:136-141,

Jude, D. J., J. Janssen, and G. Crawt'ord, 1995. I~ogy.distribution, and impaLc of the newly lntiodrrLedround and tubentrse gobies on the biota ot the St.Clair arxl Deuoit Rivers. pp. 447400. In Ae LakeHuron Ecosystem: Ecology, Fisheries, andManagement, Ecovision 5'arid hfonograph SeriesM. Munawar. T. Edsall, and J. Leach eds.!, S. P.B. Academic Publishing, 'Re Netherlands,

Jude, D. J�R. H. Reider, and G. R, Smith. 1992.

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basin. Can, J, Fish, Aquat, Sci. 49;416421,KJer!Ls, P, L., P. C. Fraleigh, and J. E. Lawniczak. 1996,

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- ed.!. The Freshwater Fishe~ of Europe,AULA-Verlag Wiesbaden.

MSs, E., J. H. Leach, J. T. Carlton, and C. L. Secor.1993. Exotic spedes in the Great Lakes: a historyof biotic Nises and anthropogenic intaxhctions. J.Great Lakes Res. 19:1-54.

Miler, P. J. 1984a. Introduction: strategies and tacticsin fish reproduction. pp. 45-53 In FishReproductiort. Wootton, R. J. ed.! AcademicPress, Ltd., London.

Jvtmler, P. J. 1984b, Tokokigy of gobies, pp. ]19-1S3.

t!avid J. Jude

ln Fish Reproduction. Woo ton, R. !. {ed.!,Acadentic Press, Ltd., London.

Miller, P. j. 1986. Gobiidae. P. 1 9-1 !95. lnWhitehead, P,I. P,. M.-L, Bauclwt, J.-C. Hureau,j. Nielsen. L. Tortonese, IW., Fishes of theNorth-east Atiantic and the Mediterranean. Vol.Ill., UNHSCO, Paris,

Moyie, P, B., and j. j. Cech, jr, 1988. Fishes: AnIntroduction to Ichthyology, Prentice Hall,I'.nglew xid Cliffs, N3, 559 pp.

Moyle, P. B. 1991, Ballast water introductions,Fisheries 16{ I !:4-6.

Piuchuk, V. I. 197 l. An unusual goby specimen fromthe bay of '1aman. 3. lchthyoiogy 1970 I !! vol.5;689-691.

Pratt. I!. M,. and W. H, Hiust. 1992, Rvffe,Gyntnocephaius cernutts: newly introduced inNorth America. Can, J. Fi sit, Aquat. Sci.49;1616-1618.

I'rotasov. V, I. V. I. Tzvetkov, and V, K. Rashchperin,1965. Acoustic signalixation of round goby Neogobiur nteianostontus! trom the Azov Sea.journal of General Biology Russian!26,2; 151-16 !,

Rosenberg, G., and M. I.. Ludyanskiy, 1994. Atuimehclatural review ol' Dreissena Bivalvia:Dreissenidae! with identitlcation of the quaggamussel as Dreissena bugensis. Can. 1, FLsh. Aquat.Sei, 51; 1474-1484.

Spidle, A. I'., !. L, Marsden. and II. May. 1994.Idcntitlcation of Hie !rest I akes quagga mussel asI!reissena bugensis I'rom the l!nieper River,Ukraine, on the basis of alloI,yme variation. Can.J. Firh. Aquat. Sci. 51; 1485-1489,

Skora, K.l .. and j. Sttilarski. 1996. Neogobiusntetannstomus Pallas 1811!, A new immigrantspecies in the Baltic Sea. pp. 101-101t, InEstuarine Ecosystems and Species, I:wa.Styczynska- Jurewlcz I.I!!. I niceedings of the 2ndi~onai Ihtuary Symposium held in Gdansk,18-22 .k%ober 1993. Crangon Issues of the MarineBiology Centre in Gdynia No. I, Gdynia, 1996.

Stelngraeber, M.. A. Runstrom, and P. "fheil. 1996,Round goby {Neogobiirs nte anostomus!distribution in the Iihnois Waterway system ofmetropolitan Chicago. U.S, Fish and WildlifeService Publication, Fishery Resources Office,Ottalaska, WI.

Vass, D. F., A. G. Vlasbiom, and P, De Koeijer. 1975.Studies of the black goby Gobius niger, Gobiidae,Pisces! in the Veerse Meer. SW Netherlands,¹theriands Journal of Sea Research 9:56-68.

r'jtorjet /1 Pr/jejjj, /r.

IvsttstbsrRospsnttgog

Exponditttrss jn fated!

/Yatttbsr itrtjtEsjtondtssttvs

/i/'atnberlnfestrsl

jb Total

SO 0 0005'

$0 0 000rb

$0

$0$750 0 00/ Js

0. 0//tt

0. 029'

0 0399i

$7,500$7,500

$20.000

$25,000

$20.000

$27,000

$27,100 0.0395t

S 73,000

S441,700

$ 563.000

$88.000 0 /2754

0 701st56 $484,800

$ J63,000

$723,000

$4,574. 000

$ 5.846.000

28

0.8/Jtti

$0

6 62254$4,574.000

53, 747,500

56,5/6,9/0

$30,064, /OO

Jd 8. 4645fi

31 03494

Jl. 0709$

22

38 $21.435,610

$35,274.020/23

$69.0i 0, 780 S46,032. 7/0/74

Table f. Ttstsd reported ttxpessofitstres va gebsvs ssstsssei-refsstett activities, lttlt-!99S, isscltsstissjt tttsmber offacilMesrstspattdisttt, sstssssber vf faCi7itiea' witjt erpettditstreg, sssssssber vf facilities issfested sst ttte tiase vf tjse stsssty, tsstsdeXpeSSStitttlett, esspenditsssvte at iejictesj facitities, asstt percestt vf tvtai ecvssvsssic isstpact by toater «ee categary.

Mon-Xavigoti on Canals

Aqooriton Trtotne Parks

Jovwtgv Troastttttlt Plants

Golf Cottrsos

btarjnas

ootvtatjon Foci jistos

/nstjsttsions

/tttpottttdntontslRoservojrs

//asc'jwrt'osjdtjttactt jtttrs

Pjav jgaston Loejts

$/ttttjsteglXavigoti on

Scoots Rivorttoys

Agvnciss

/advs srtes

8'ator Treat<nant

Bsotrts Povver Generation

usable reSpt<nSCS Were recciVed, a 56.92% return rate.'1'hree hundred thirty nine tacilities reported expendingfunds related to zebra mussel impacts see Map!.lnformalion solicited included: facility type andloCation; source water tXXly; degree of facility waterUSC; 'typeS Ol Tehfa ntUSSel-related impaeis; zCbfamussel monitoring and control w1ivities; and, 13categories of zebra tnusscl-related annual costs froml989 through 1995.

'fhlee hundred thirty nine facilitics ~d totalzebra mussel-related expenses of $69,070,780, with aminimum reported expenditure of $4tN, a maximumexpenditure of $5,953,GN!, and a mean expenditure ot$205 57t ! per facility see Table and Figure 1!. The bigspender was nuclear power plants with a meanexpenditure of $786,670 per fedlity, actx!unting for26,2% of the total repeated zebra tnusse! impact. Othermajor water user categories included: drinking watertreatment facilities, with a mean expenditure of

$214,360 {31.03% of total reported impact!; fossil fuelelectric generating facilities, with a mean expenditureof $145,620 per facility �6,02% of the total reportedimpact!; and, industrial facilities, with a meanexpenditure of $167,030 per facility 8.46% of the totalreported i~!. Total annual expenditures increasedfrom 1989 $234,140! to 1995 $17,751,000! as themussel's North American range and the nuruber oftaCHitteS affected increaged Ftgure 2!,

No zebra mussel-related expenses were reftortedfor non-navigation water trutsptXt canals, aquariumtheme parks, or sewage treatment fac11ities. TwonOtunfegted golf courses reported tOtal mOnitOringexpenses of $750 from 1993 through 1995. Twoinfested marinas, one on Lake Champlaht and one On

Econumir /tnpacl <// 7mbra .'If«~~eh - //vie/ti r// rhea /VV5 /Vga/ <c'/ Alf~tmatii!n /'/rart'espouse 3/eely

IEconomic Impacts of Zebra Musse s X 510 0!

Elec/r;c�0

pigare I. Surnrnot y of /os zebro masse/ economic i/npac/s hy water use ca/egory /Vote /ag/sr/'S/hteic scN/e.

Total Annoa I Zebra MUssel-Re/ated Expend&re

15000000

10000000

1989 1990 1991 1992 1993 1994 1995

Toast eaeaud asbnr siss/asfm~t capeahhev/a Pr /s/f severer s/sret' ce/tegorw's.

37

the Niagara River, reported total zebra mussel-relatedexpenses of $7500. One public. recreation area on aninfested pubhc iinpoundiuent reported $20,000 of zebramussel-related expenditures, mostly for monitoring andplanning. Two institutions, a uni versity campus on LakeMichigan and a residential care facility on LakeCharnplain, reported total zebra mussel-relatedexpenses of $27,000; $2,000 for monitoring and$25,000 for preventio~. Nine noninfested publicimpoundinents in three states reported total zebramussel-related monitoring expenses of $27,100. Tlireefish hatcheries in three states reported zebramussel-related expenses of $88,000 from 1993 through1995, of which $73,000 was spent at two infestedfacilities. The uninfested facility uses ponds as its watersource, one infested facility uses the Mississippi River,the other infested facility uses Lake Chainplain. Therewas $67,000 spent on preventive measures, $15,000 onresearch, $5,000 on planning and engineering, and

$1,000 on monitcxing,Responses were received from S8 public

navigation lock facilities �8 of which are infested! in10 states. 'Ilte facihties are on the Allegheny, Arkansas,Cumberland, Mississippi, Monongahela, Ohio. andVerdigris Rivers and their tributaries. Fifty-six of thefacilities repoited total cumulative zebra mussel-relatedexpenses of $484,800 from 1991 through 1995.$441,700 91,11%! at infested facilities, $43,100 atuninfested fadlities. Navigation locks represent 13 9%of facilities responding to the survey, 1S.7% of infestedfacilities, and 16.5% of facilities reporting zebratuussel-iulated expenses, yet locks accounted for only0,7% of the total reported seven year zebra musseleconoinic impact. For this reason, any aggregate figurefor all water user categories, including navigation locks,which shows an average per facility zebramussel-related expense wiLL be skewed toward the lowend oi the scale.

Charles k O'Weitt. Jr

rec9"

Figure 3. Indttstrial facility expenses Nt infested apgd uttiIifested facilNes ia $'1006s! by year.

Flay-six kx;ks spent an average of $3,416 each onmonitoring, ranging from $400 to $31,000, accountingfor $191,300 �9.5%! of reported navigation lockexpenses. The second largest expense category wasfacility retrofit, with two locks spending $100,000, Oncfacility spent $75,000 on m~anical controls; twolocks spent $36,000 on staA training; and three locksspent $34,000 on planning and engineering expenses,Several facilities were expected to close for severaldays in late 1995 for mechanical removal of mussels� $32,000 revenue was ex~ed to be lost duringthese closures. Other expenses included nonchcmicalcontrols. research. and prevention.

One response was received from a shipping relatedentity with numerous vessels on the Arkansas, Hudson,illinois, Mississippi, !hio, Tennessee, and Missouri

Rivers and the Great Lakes. Vessels were reported tohave been mfested since 1990; $563,000 worth of zebramussel-related expenses were incurred in all categories.The single largest category of expense, $220,000�9.08%!, was for vessel retrofit, followed by $99,000�7.58%! for nonchemical treatments and $92,000�6.34%! for lost production/use, Other expensecategories included: mechanical treatment, planning andengineering, training, research, prevention, monitoring,chemical controls, and filtration. It was reported thatall new vessels are being constructed with zebramussel-proofing nieasures "built in."

A National Scenic Riverway reported that it wasnot yet infested but was proactive in its response tozebra musseis, implementing a monitoring and usereducation programs, signage, boat inspections, and boat

lac>n<»»ir 4»V>r>c'i »f 7whra ht»>sr4i - Rr~»ns >g ihr I>'kt Vati>»>el /H>u bt»~e'I bi/i>r»»«i»» Clruri»gh»»~ 5i»dv

>CCC!l

Fit{»re S. Water treat»se»t pfa»C espendit»res {' by stat~evince, i» ji0D{is!, 1%{it-DOS i»ef«sise. lvate: ingarith»«s seaie!

Fig«re 6. Water treatsnent pkuat mpemes at «sfestsd and»»issfestesf faeilit~'es fi» gllNos! by year

39

cleaning stations at access points. The facility spent$723,000 on monitoring, planning, prevention, research,and training activities from 1992 through 1995.

Five government agencies two federal, three state!verbally reported incurring $4,574,0{� oi zebramussel-related expenses from 1991 through 1995,6,62% of the total reported economic impact. ln allcases, the money was spent on mussel control research,

Fifty-six industries in 13 states and onc provinceresponded, 22 �9.29%! of which reported that they areinfested. No industrial expenses were reported for l989.'lturty-five �2.5%! of the industries reported acumulative total zebra mussel-related expense of$5,846,000 from 1990 through 1995; $3,747.500{'64.1%! at infested facilities, $2,098,50{! at uninfestedfacilities Figure 3!. industrial expenses represented

8.46% of total reports zebra mussel {xeric i~.The largest number of mponses from a single

geographic region came from 18 facilities on theMississippi River with a total expense of $753,0{I�2.88% ot industrial expenditures!: seven facilitiesdrawing their water fnm the Great l.akes r~$2.815.0{� of expenditures �8. l 5%!, This disparity inimpact can he attributed to the Great lakes facilitiesbecoming infested much earlier than those on theMississippi. Expenses generally increased from 1991,with the exception of 1992 which, at $1,423�500, wasthe second highest annual expenditure.. 1992 was alsothe only year in which expenditures at uninfestedfadlities $924,000! exceeded those at infested facilities $499,5{!f!!.

Fight industries {Ave of which ate infested! spent

P'igure 7. Water Ere»tercet pfa»r expe»v<s hy category ia flnÃJ»!,

IiI

k'igloo It. ~ ge»eerie» s»araaey erpe~s i» SiNNs! by year.

a total of $2.657, XXI {a mean expenditure. of $332.125per facility! on preventive measures, ac<.«unting f<x45,45% «f thc t<ital reported industrial expenses, thclargest single expense category f-igurc 4!. 'theseexpenditures, howevn', were very unevenly distributed.ranging from $4,NN to $1,5 X!, XX! at facilities withwater use capacities ranging froin 4 million gallons perday mgd! to 300 mgd mean c,apacity = 60,3 mgd!,Excluding two facilities that plot as outliers, the meanindustrial prevention expense at facilities with water usecalxtdtics h<uween 4,000 and 5 I, XX! mgd was $92,833.

'11tc second largest expense category was chemical<xmtrol mca»ures, Seventeen indu»tries with water usc

artie» ranging from 4 to 3{XI mgd {mean capacity51.5 nigd! spent a total ot $1,358. XXI mean

expendituf<; <lt' $79,8II2 per facilit! !. 23,2%i <if the lotalindustrial expenditure, Twemv one indu»tries with

water use capacities ranging from 3 to 94 mgd spent atotal of $781,0{X! mean expenditure of $37,190 perfacility! on planning related expenditures. Twenty eightiaciiities spent a total of $401,500 incan = $I4,393!on m<mitoring wwivities, Five fadlities spent a total of$241, XX! mean = $48,200! on retrofit of existing plant.I. ight facilities spent an average of $20,250 for a totalof $162,000 on mechanical control alternatives. V»olacil}ties spent a total of $128,000 on other thermaland coatings! control gctmdogies. Sixteen facilitiesspent a total o{ $l02,500 mean = $6,406! on stafftraining, and two facilities spent a total of $15,000 onresearch activities. No funds were spent on lostproduction, filtration. or nondtemical, nonmechanicalcontrol techniques,

Ru»ponses were received ftom l 60 drinking watertreatment plants i " I I'il in 3{! states and two provinces.

I.'<<>@spur trrviiiit cif 5+ri hhuirb - Prius«zf 1ar f 'w5 lvu«r>nai /wl>m Muvmf Injnrrira«cm c'Irgri«ghaggp shafy

Fig«r«9, Hykeekrbir. ge««r«no«expenses in fl000s! ar is/«~ «ed ««infest«rf fsciliti«v. by y««r.

There were ]00 facilities with a combined wafer usageof 5,677,440 mgd �2.5% of a}t W1T's responding tothe survey! that reported they had spent s combinedtotal of $21,445,610 on zebra mussel related activities,31,05% of the tota} reported zebra mussel etvaomfcimpact. 'Ate state with the greatest number of watertreatment plants responding was Alabama with 27responses, one of which was infested, New York hadthe second largest response, 21, of which 15 areinfested. The states/provinces which spent the greatestamount of money on zebra mussel related activities atWTPs were: New York $7.63 million, 35.6% of at}WTPs!, Maryland $6.11 million, 28.5%!, andWisconsin $2.43 mi}}ion, 11.3%! Figure S!, Watertreatment plant expenses began in 1989 in the GreatLakes region, with seven facilities reporting a f~aaI

expenditure of $1 �. }4f! compared fo three tfon~Lakes facfl}ties spending s total of only SI6,000. Boththe number of itnpacfed p}ants and total expendituresincreased on a yearty basis with the Great I Aesoutpac/ng other regions of the amCry until 1994, when49 non-Grea l~ f'abilities spent a combined total of$3,483,300 compared to 41 Great Lakes facilitiesspending $233t,NX!. Over the enfire period, GreatLakes facilities spent a total of $11,717,900 S4.64%of W}V expenditures!, while non-Great Lakes facf}itiesspenf $9.727,700,

From 1989 through 1991 the majority of WTPexpenditures were spent responsively by infestedfacilities, '%is changed in 1992 when proactiveexpenditures at noninfesft~f facilities began fo exceedthose at infesfmf p}ants, fl>ii tread wss vm' ev}dent

Agar/es R O'Wrdl. Jr

Figtsre ll. l'assil fuel electric generafian facility expenses in $'/00 bt! at usfexted and nninfested faciMies, by year.

Fjgnte l2. Fcevil fact ekcsric getnvutlovs facility expenses by categary in gMR&!,

from 1993 thrtntgh 1995 with noniniestcd facilities outspending infested ones by 47% in I 99'3, 487% in 1994,and 244% in 1995, '1!tirty eight infcsced tacilities totalwater use ot 932,9 X! rngd! rc7orted that they spent stotal af $6.526.910 �0.4% ol' %AT' expenses!, whilenoninfested facilitics spent the remaining $14,918,7 X! Figure 6!.

Thirty-Ave water treatment plants combined toLdwater use capacity of 90M mgd! spent a tata! of$63g5,570 on physical plant retrciAt �9.78% of all%TP expen~!, with a mean per facility expenditureof $182.44{! Figure 7!. ln a!i cases. this was to providecapability for preoxidation of intake water at the sourcewater end ot the facilities >ntakes, Ihe second largestcategory was plsreing and engineering expeases, with55 water treatment plants combined total water usecapacity ol 4 81 trt" 1l spewing s total ol $6.229.450

�9.{ % of a!i Wll' expenses!, with a mean per facilityexpenditure of $113,265. Thirty-two facilities cotnbincd total water use capacity of 36.17 tngd! spent$6,22!.46 ! {29% of aB Wll' expenses! on chetnicalcontrol activities, with a meso per facility expenditureof $194,42 !. <!f the 60 faciUties that reported usingchemical treatment methods, all but two are usingoxidizing chemicals, with various forms of chlorinemaking up 70% of the total, chlorine dioxide 15%,potassium permanganate 12%, ozone 2%, and bromine1%. Two facilities reported using polyquaternaryammonium compounds. Twen y-one facilities spent atotal of $926,2{X! on prevention-oriented activities, andN! facilities spent $9l4,7g{! on monitoring. Otherimportant categories included: mechanical retnoval hard-helmet divers and pigging, 15 facilities,$236.59t!!. stat't' training {~s facilities, $161,760!,

pissrrv l3, Lc.'osomic ierpacr on inpvied Nnd sniefesrcd ilicker power pkrtas iw SI0Ãfs! hy yoor.

43

ntinchemical controls filtration. 2 facilities, $142,5tX!!other activities use of polymers, plasma sparking, andalternating intakes, 6 facilities, $1 8.670!. research 8facilities, $98,630!, and, lost revenue or prtiduction $20, NO at 1 facility!.

7'here were 133 responses received trom theelectric ge,neration industry, by far the largest singlesurface water user group to be economically impactedby Iebra mussels, with 124 respondents reporting anindustry-wide expenditure ot $35,274,020 froin 19Nthrough 1998, 51.07% of all reported zebrainusseI-related expenses 9:igure 8!, The reason for thislies in the operational differences between this industryand other water users. A drinking water facility, forexample, might treat two or three hundred milliongallons per day, whereas a power plant, with itstremendous water needs for heat exchanger cooling,bearing lubrication, transformer cooling, and firecontrol, to use two or inore billion gallons per day.I'umping so inuch water through power plant watersystems brings those systems into direct contact withastronomical numbers of mussel larvae, juveniles and~dulls, and results in a greater potential biofoulingimpact. ln response to such high levels of potentialimpact, the electric industry has expended higher levcdsof funds for research, monitoring, retnediation,control/treatment, and prevention than have otherindustries,

lbree non-generation electric industry entities, onea research cxinsortium representing a nutnber of publicand private electric generating companies in thentxtheast, one a major public getsxation authority inthe south, and one ccmyaree of5ce af a major privateelectric generanon corptoration in the southeast havespent $4.354,420 on the zebra mussel situation, 12.34%of aII electric industry zebra mussel dollars �,3% ofall reported zebra mttsseI related expenses! since 1990,All three entities have been proactive respiring to the

zebra mussel issue, undertaking monitoring programs,rate payer education programs. prevention prognuns,and major RkD research and development! programs.

Twenty-three hydro generating stations in 11 statesresponded to the survey. 13 �.319.NX! megawatts'! ofwhich are infested, and 22 t,419, Kt0 megawatts! ofwhich spent money as a result of the mussels, The totalhydropower expenditure was $1.759,0N �.99% ofelecMc induitiy expensesl with a mean expenditure of$79,950 per plant. Oi this, $1388,000 90.28%! wasspent at 13 infested facilities. $171,000 at ninenoninfested sites Figure 9!. The largest hydro expensewas $722.0tl0 for cheinica! control �1% of allhydropower costs!, with 10 facilities utilizing oxidizingchemicals and one using a nonoxidizing moliusckide hgute 10! 'Ate mean chetmcai control expense perfacility was $34,380. 7be second greatest expense $393.NN, 22.3%! was for planning and engineeringexpenses mean expenditure of $17,86S!. followed by$255,000 �4.5%! for prevention programs in all cases,this was for installation of systenis for oxidizingcheinical Injection!, and $222,000 �2,6%! formonitoring,

Eighty-five fmml fuel powered electric generatingstations in 19 states responded to the survey, S2 �4,970inegawatts! of which are infested, and 76 �8539megawatts! of which indicated that they had spentmoney as a result of zebra mussels. Sixty reiyanses�0.6%! were fiona nrtrthern states, the remainder fromsouthern, The total fossil fuel electric generating stationexpenditure was jl1.067,200 �1.3g% of total electricindustry expenses, 16% of the total reported zebramuaael itttparx!, Of tjtis total, $10.868,200 98,2%! waSspent at the 52 infested facilities, with $199,0{10 spentat the 24 noninfested sites tl igure 11!. Ae meanexpent8ture per fossil fuel station was $145.620.

The largest fossil fuel plant expense was$3,670,SOO for chenucal control at 36 facilities

representing 23,7 XI megawatts �3.17%- tit' all fossilfuel costs, I !.41% of all reported ptiwer plantexpenses!, with 26 facilities utilizing oxidizingchemicals, IO using molluscicides, and I0 using bothoxidizing chemicals and molluscicides Iiigurc I 2!. Themean per Pant chemical control expense was $ 1 01,960,The second greatest expense, $3,329, X� �0. !8% ofall fossil fuel costs, 9.44% of all power plant costs! wasfor retrofit projects at 2t! facilities representing I I,323megawatts for chemical injection systems, cathodicprotection systemr, and waste heat recirculationreplumbings!, with a mean expenditure of $16S.450.This was followed by SI,054,I00 for monitoringexpenses at 70 facilities �8,539 megawatts, a meanexpenditure of $15,060, 9.52% of fossil fuel expenses,'3.0% of aII power plant expenses!, Other major expensecategories wee planning and engineering, research. andlost production $475,fXN at six facilities!.

Responses were received from 23 miclear powerplants in IS states and tine province representing atotal generating capacity of 28.896 megawatts!, Ofthese� 12 IS,877 megawatts! reprtrted that they areinfesled by zebra rnussefs. All of the nuclear facilitiesreported spending money on zebra mussel relatedactivities, Sixteen responses were from fadlities locatedin the Great Lakes. Nudear power plant expenditurestotaled $I8,093,400, 51.29% of the total electricgeneration industry imixtct �6.2% of the total reportedzi'.bra mussel economic impact!, making this the largesiwater user category Impact ln the stlldy. !f ttus,517,607,900 97.32% of nuclear expenses, 49,92% olthe tOtal electri induslry cost} was spent at facilitiesthat are Infested by rnussels. with the remaining$45�S00 spent at unlnfested facilities Figure I3!. Themean per fadlity expenditure was $786,670.

'Ihe largest nuclear plani expense was $5,303. KÃ!tor facility retrofit at six planb with a i<ital generatingcapacity of 6,209 megawatts �9.3I% of all nuclearcosts, I5.03% of all power plant expenses, 7.68% ofall reported zebra mussel expenses!. In each case, theretrofit was instaliation of source-end-of-pipe oxidizingchemical injection systems at an average of' $883,NK!per plant {Figure I4!. 'Ihe next largest category was$5.2I I,50f! at 13 facilities I6,lt27 megawatts! forchemical controlac ivities, an average of $4N!.9N! perplant �8.8% of all nuclear expenses, 14,77% ol allpower plant costs, 7.5S'k of total reportedexpenditures!. Five ol' the facilities reputed usingoxidizing chemicals, one uses mo'lluscicides, and sevenuse both oxidizing cheinicals and mollusclcides. Inaddition, several other facilities also reported usingchemical controls hut did not quantify those expenses:two reported using oxidizing chemicals, onemoHuscicides, and three use both oxidizing chemicalsand molluscicides. 'Ihe third major expense category.$3.412, XN �8.86% of aII nuclear plant costs, M7%of all power plant costs, 4.94% of all reptxted costs!was tor prevention projects at three plants, in all caseschemical injection systems, at an average of $1,137,300per plant, It should be noted here that these facilitiesconsidered the chemical control systems to be aprevention expense, and did not include it in theirretrofit costs; it could be argued that these expenseswere, in fact, a retrotlt expense. which would Increaseretrofit to 48.17% of all nuclear facility expenditures�2.62% of aII reported zebra mussel expenditures!,Other major expenditures induded: $I,580, KX! at 10facilities for planning and engineering expenses;$1,271. Q! ai five facilities for mechanical controlac0vities: and, $968.9t!O for monitoring activities at 21facilities.

Fjgare l4. Navar geaemrieg sNatroe creaser is fl000s! bp earcgery.

April l997Volume 3, N'utnher 1

great lakesprograItt

Great Lakes

Researth Review

KESHIUM

Workl figfurr Orlrl'Sells'

Introduction

Charles R. 0'¹ill, Jr.

What Other Ecosystem Changes have Zebra Mussels Caused in Lake Erie:Potential Bloavailubility of I'CBsJoseph V. DePinto and Rajagopal Narayanan .,

Zebra Mussels-and Benthic Macroinvertebrate Comtnunities ofSouthwestern l.ake Ontario and Selected Tributaries: Unexpected Results?James N, Haynes

Surveillance for Ruffe ln the hereat Lakes � An OverviewSandra N. Keppner, Thomas R. Busiahn, Jerry MeClain, and G 17

Round obies: Cyberfish of the Third MillenniumDavid J. Jude

Economic Impact of Zebra Mussels � Results of the]995 National Zebra Mussel Information Clearinghouse StuCharles R O'NeilI, Jr. 35

Prier' oa ~rycled pgper

Produced bg: Great Lakes ProgramUniversity at Buffalo202 garvis HallBuffalo, Mr l426~0O

Editor: Helen M. Domske

Design/LtJgout Editor: Monica S. Moshenko