Can a naturallyimpoverished boreal Ephemeroptera,Plecoptera, and Tnchcptera (E PT)faun a serve as anindicatorof water qual ity?
by
Tamm y M.Lomond,B.Sc.,B.Sc_(Hons_)
A thesis submittedtoth e SchoolofGraduateStudies
in partial"fulfilmentof the requirementsfor the degreeof
Masterof Science
DepartmentofBio logy Memori alUniversityof Newfoundland
199 7
81. John 's Newfound land
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ABSTRACT
Biomonitoring of smallboreal water-catch men tshas becomeincreasingly importantforsmallhuman communi tiesin Newfoundland,Canada. Benthic macroinvertebratefauna are commonlyusedto assess con ditio n s of water- catchments. However, Newfoundland hasa veryimpoverished freshwaterfauna due toisolationof the island from themainland(faunal source) ,reduced habitat diversi tyand recen tglaciation of the island. Questions addressed by the study were: how sensitive isthi s faunatodifferentenviron menta lgradients,and will the faunabeusefulinbiomonlt or ingprograms on theislan d?
The study examined the relative divers ity andabun dance of the Ephemeroptera,PlecopteraandTric hoptera (EPTj compone ntofthe benthic rnacroin vertebrate fauna in 23lake-outletsinsix water-catchmentsofnorth eastern Newfou nd land . Fauna lcomp osi tionand structurewere related to gradientsof naturalandhuman impacted environmentalvariables of the sites sampled .Sixteen envir onmenta lvariableswere measuredduringMay and July1995,andMay and July 1996 collectiontrips
PrincipalComponen tsAnalysis(PCA ) of the environ men ta ldatain dicated thatthe 23 sites repre sented a broad rangeof stream anddrainage basin characteristics. This was expectedfromsites that ran ged from highly urbanized sitesto siteswithlittle human disturbance. Con centrati ons ofseveral chemicals,
iii
conductivity,andpH were correlated withdisturbanceon axis one An a ly si s oftheEPT datashowed shiftsincommunitystructurerelated to chemicalvariables,disturbancelevel.and studyarea.Generally,EPT diversityand abundancewere lower in the physicallydisturbed and pollutedurbansites,and werehighe st in physically disturbedbutrelativelyun pollut edru ral sites .Principle Components Analysisalso showed trends in taxa diversityandabundance.Taxa correlated with presence-absencePC-IincludedB.pygmaeus,B.macdunnoughi, E.prudentalis,Paraleptophlebia
soo..
S.vicarium, Leuctra spp.,Polycentropusspp.andPlatycentropus sp.,whichoccur in a wide varietyofrunn ing water habitats ,but have low tolerancesof disturbance(Edmundset sl,1976;Larson and Coiba19 83;
Lena t1993;Lang and Reyrnond1995).These taxa tended tobe absent fromthe high ly disturbed 51. John's sites,but present at most remain ing sites Taxa correlated withrelativeabundancePC·IIwereH.sparna andChimarrasp ., which have low toler ancestopollution(Barga set et.1990;Lenat1993).The se taxa had Jow abundances at 51. John's sites. Therefore,itwa s concludedthat the im p ov eri she d EPTfaun a ofNewfoundlan d canserveas an indicatorof water quality.
ACKNOW L EDG ME NTS
I wish to extend sincere gratitude to my supervisor, Or.MurrayH. Coiba,for his Insight and quidance, and for always being available for help. I'd also like to thank Murray for help with the site descriptions, particularly for his knowledge of the vegetation at the sites and history of human disturbances.I would alsolike to thank the members of my supervisory committee,Drs.Lawrence Felt, Roger Pickavance and David Schneider, for helpful suggestions and constructive comments on the thesis.
Special thanks to my very good friend andlab-mate Jose M.Perez whose help withevery aspect of this project is sincerely appreciated.
Funding for thisresearch was received from the TriCouncilEco-Research Program, a federally-fundedprogram administeredby the Social Sciences and Humanities Research Council of Canada (SSHRCC),the Natural Sciences and Engineering Research Council(NSERC) and the Medical Research Council (MRC).
TABLE OFCONTE NTS
Page Abstract
Acknowledgements ListofTables Listof Figures. Preface
1.0 Overview of study 1.1 History of biomon itor ing 1.2 Thepresentstudy
2.0 Loca tion anddescriptionofstudy areasand sites 2.1Studylocation
2.2 Materialsand methods. 2.3Sitedescriptions.
..ii
vii
.1 ..3 .3
... .. .. 10 .10 ... . 13 .15 3.0 Comparisonof 23lake outlet sitesof four study areasinnorth eastern Newfoundlandbased on chemical/p hysic al character isticsand human
distu rbances ...42
3.1Introduction 3.2Materialsand methods 3.3Results . 3.4 Discussion
42 45 48 . .. .51
4.0 Comparisonof the benthic Ephemeropter a, Ptecopteraand Tric hoptera (EPT) fauna of 23 lake outlet siteswithdifferentchemicalan d physic al characteristics and levelsof human distur bance 64 4.1 Introduc tion
4.2 Materi alsan d methods 4.3Results
4.4 Discussion 4.5Conclusions 5.0 Concludingremarks. LiteratureCited Appendix 1 Appendix 2. Appendix 3..
Appendix4. Appendix 5. Appendix6..
...64 .75 .. .87
...102 ...115
·169
·172 180
·183
·185
·186
·189 .203
Ta ble
LIST OF TABLES
Page Chemical and physical characteristicsmeasured at 23 lake outlets,their
codes,and noteson measurement. 33
Classification of streambedparticles (adapted from McCreadie (1991»)34 Chemical characteristics of 23 lake outletsin Bonavista,RandomIsland, Come-by-Chance and St. John's ,NF,recorded duringMay and July 1995, and May and July 1996(mean valuesof 4 sampling dates) ..35 Physicalcharacteristicsof 23 lake outletsin Bonavista,Random Island, Come-by-Chance and St. John's ,NF,recorded duringMay andJuly 1995,
and May and July 1996 ....37
Results of ANOVA(u sing GLM command)to test for significant differences in chemical variables with respect to various physical environmental variablesfor 23 lake outlet sites.Values inbold indicate tests for which the residualsmet the assumptions of the ANOVA modeL Valuesunderlined indicate those tests re-run using randomization. Remaining p-vatues were accepted as they would notchange significantry after randomization..56 Results of randomizations (using Mean Square of Error) to test for significant differences in chemical variables with respect to various physical environmental variables for 23 lake outlet sites. Randomization tests were carried outonly for those tests for which the residuals did not meet the
assumptionsof the ANOVAmodel 57
Results of Fisher'spairwise comparisons for those chemicalenvironmental variables that were significanlfy different between study areas (B = Bonavista,R=Random Island, C=Come-by-Chance,S
=
St. John's) Areas with same letters are not significantlydifferent, .58 Results of Fisher'spairwise comparisons for those chemicalenvironmental variablesthat were significantly differentbetweenlevels of disturbance(1= low,5 = high).Disturbancelevels with sameletters are not are significantlydifferent., ..59
Principal components analysis of the mean chemical and physical
charact eris ticsof 23 lake outlet sitesin Bonavista,RandomIsla nd,Come-by- Cha nce,and81.John' s,NF,duringMay and July 1995, andMayand July 1996.Spearman'sRankCorrelationCoefficients(r$)were used to assess the relationsh ip amongthe PC-scoresan d environmentalvariables...60 10 Interpretationof the principalcomponentsanalysisof the meanchemicaland physica lcharacteristicsof 23lake outletsitesinBonavis ta(B),Random Island (R), Come-by-Chance(C),and 81.John's(8 ), NF,duringMay and
July1995, andMay and July 1996 61
11 Results of ANQVA (using GLM command) and Fisher's pairwise comparisons to testforsignificant differences in environmentalPC-Iand PC- II between study areas(B::Bonavista,R::RandomIsland, C:: Come-by- Chance, 5 :: 81. John's). Areas withsameletters are not significantly
different .63
12 DiversityofEPTtaxa collectedat 23lake outletsitesin Bonavista(B), RandomIsland(Rj, Come-by -Chance(C),and S1.John's(S),NF,during May andJuly 1995.andMay and July1996. Number of newtaxa recorded at each siteduringeach samplingdate isindicatedin parentheses .117 13 Prese nce-absenceof EPT(Ephemeroptera, Plecoptera,Trichoptera)taxa collected at 23 lake outlet sitesin Bonavista.RandomIslan d, Come-by- Chance.and 81. John's,NF,duringMay and July 1995,andMay andJuly
1996. .118
14 Summary of total diversi tyand mean diversityof EPT taxa collected at 23 lak e outletsitesinBonavista,Random Island, Come-by-Chance , and 51.
John's,NF, during May andjuly1995, andMay and July1996. ..122 15 Results of ANQVA(using GLM command)to test for significantdifferences in EPTdiversitymeasureswithrespect to physical environmental variables for23 lake outletsites.Valuesin boldindicate testsfor whichthe residuals met theassumptionsof the ANQVA mode l.Values underline din dicate tests re-runusingrandomi zation . Remainingp-vatues were accepted asth ey wouldnot cha nge significantlyafter randomization. 125 16 Results of randomizations(using MeanSquareof Error)totestfor sign ificant differencesinEPT diversity measureswithrespectto physical environmental variablesfor 23 lake outlet sites.Randomizationtests werecarriedout only forthose testsforwhich theresi dualsdidnot meet the assumptionsof the
ANOVAmodel. ...126 17 Resultsof Fisher'spairwise comp ar isons forthose EPT diversi tymeasures that were significa ntlydifferent between study areas (8=Bcnavista ,R= Random Isl and, C=Come-by-Chance,S=St. John's).Areas with same
letters arenotsignificantly different 127
18 Resultsof Fisher's pairwise comparisonsfor those EPT divers itymeasures that were sign ifican tlydifferentbetween level s of disturbance(1
=
low,5=
high). Disturbancelevels with same letters are notsignifica ntly differer'lQ7 19 Results ofFisher'spairwise compari sons for thoseEPT diversitymeasures that were significantlydifferent betwee n streamorders. Order s with same lettersarenotsignifica ntlydifferent ..128 20 Spearman'sRank Correlation Coefficients to evaluate therelation between EPT diversitymeasures andenvironmentalPC-IandPC-II(Chapter 3)and chemical variablescorrelatedwithenvironmentalPC-Ifor 23lake outletsites ..128 21 Resultsof ANOVA (using GLM command ) to test for significant diffe rences infun c tiona l feeding group diversity measureswith respect to physical environ menta l variablesfor 23lake outletsites.Valuesinboldindicatetests for whichtheresidualsmetthe assumptionsoftheANOVAmodel.Values unde rlinedindicatetestsre-ru nusing ran domization.Remaining p-values were accepted as theywould not changesignificantl yafterrandomizatitBO 22 Resu lts ofrandomizations(using Mean Squareof Error) totestfor significant differencesin FFG diversity measureswith respect to physicalenvironmental variablesfor23 lake outlet sites. Randomizationtestswere carriedout only forth osetests for whichthe residua lsdidnotmeetthe assumptions ofthe
ANOVAmodel 131
23 ResultsofFisher's pairwise comparisonsforthose FFG diver sitymeasures thatweresign ificantly differentbetween study areas (B = Bonav ista,R= Random Island ,C =Come-by-Chance, S=St. Joh n's).Areas with same letters arenot significantly different. . 132 24 Resultsof Fisher's pairwisecompariso nsfor thoseFFG diversity measures that were significantlydifferentbetween levelsof disturbance (1
=
low, 5=
high).Dis turbancelevels withsame letters arenot signifi cant lydifferertt32
25 Results of Fisher'spairwisecomparisonsfordiversityofgatherer swhich was significantlydifferent between streamorders.Orderswith sameletters are
notsignifica ntlydifferen t ...133
26 ResultsofFisher' s pairwise comparisonsfordiversityof filtere rs whichwas significantlydifferentbetween sub stra te types(1
=
mud,2=
smallstone,3=wood,4=cobble,5=boulder). Subs tratetypes with samelett ers are not
significan tlydifferent. .,133
27 Spearman's RankCorrelation Coefficientsto evaluatethe relationbetween FFG diversitymeasuresandenvi ronment alPC-Iand PC-lI(Chap ter 3) and chemicalvariablesloade don environme ntalPC-scoresfor 23 lakeoutlet
sites. 134
28 Principalcomponents analysis ofEPT presence-abs enc edata for 23 lake outletsites in acnavrsta,Random Island,Come-by-Chance, andSt.John's, NF,during May and July1995,andMayand July1996. .135 29 Interpretationof the principalcomponents analysis of EPTprese nce- absence datafor 23lake outletsites in Bonavista(B),Ran dom Island(R), Come-by-Chance (C),and St.John's (5),NF,duringMay and July1995,and
May andJuly 1996. .136
30 Resultsof ANOVA(using GLMcommand)to testfor sign ifica ntdifferences in presence -absencePC-Iand PC-IIscores with respect toph ysica l environmentalvariablesfor23 lake outletsites.Underlinedva luesindicate thosetests re-run usingrandomization.Remaining p-varueswereaccepte d as theywould not changesign ific antlyafterrandomizatio n. ." ., ..138 31 Results of randomizations(using MeanSquareof Error)to testfor signifi cant differences in presence-absencePC-Iand PC-IIscoreswithrespec t to physicalenvironmentalvariablesfor 23 lake outletsites. Randomization testswere carriedout onlyfor thosetests with p-value s between0.015 and
O.~O .138
32 Resultsof Fisher'spairwise comparisonsfor presence-absencePC~Iwhich was significantly different between studyareas(B
=
Bonavista,R=RandomIsland, C =Come-by-Chan ce, S=St. John's) and level sof distu rbance(1 = low,5=high).Area s and levelsof disturbance with samelette rsare not
significantl y differen t. 139
33 Results of Fisher'spairwisecompariso nsferpresence-absence PC-IIwhich was significantlydifferen tbetween stream ord ers. Orderswithsame lette rs
arenot significantlydifferent .139
34 Spearman's Rank Corre latio nCoefficientsto evaluatethe relation between prese nce-absencePc -score sand environmentalPC-scores (Chapt er3) for
23lake outletsites. 139
35 Relative abunda nce of EPT(Eph eme roptera, PIecopte ra ,Trichoptera) taxa collected at23 lakeoutletsites inBonavista ,RandomIsland,Come-by - Cha nce,and SI. John's ,NF,duringJuly1995,and May and July1996142 36 Summa ryof total abundanceand meanabunda nceof EPT taxacollected at 23 lake outletsites in Bonavista,Random Island,Come -by-C hance,and SI.
John's,NF,during July 1995, and May and July1996 .148 37 ResultsofANOVA (u sing GLM command)totestfor significantdifferences in EPTabundancemea sureswithresp ect to physical environ mental variablesfor 23 lakeoutl et sites .Values underlinedindicatetestsre-run usingrandomization.Remainingp-values were accepted as they wouldnot changesignifi cantlyafter randomizati on. .151 38 Resu lts of randomizations(using Mean Squareof Error) to test for signif icant diff erence s in EPT abunda nce measure s with respect to physi cal environmenta lvariables for 23 lakeoutl et sites.Randomizat iontestswere carriedoutonly forthose tests whichhadp-varces between0.015and 0.30 0 ..152 39 Resultsof Fisher 'spairwise compar isons for total abundance whichwas significantlydiffe rentbetweenstudy areas (8=Bonavista,R=Random Island,C
=
Come-by-Chance,S=
SI. John's).Areaswith samelett ers arenotsignificantl ydifferent .153
40 Results of Fisher'spairwise comparisons for those EPT abundance measuresthatwere significantlydifferentbetweenlevel sofdistur bance(1
=low,5 =high).Disturbancelev els withsame lettersarenot significant ly
differe nt. ..153
41 ResultsofFisher's pairwise comparisonsfor abundance of Ephemeroptera which was significantlydifferent between streamordersand substratetypes (1=mud ,2=smallstone,3= wood,4=cob ble, 5=boulder ).Orders and
xi!
substra tetypes with same lette rsarenot significantlydifferent. ..154 42 Spearman'sRankCorrel ati on Coe fficien tsto evaluatetherelation between EPT abundance measures andenvironmental PC-Iand PC-II(Chapter 3)and chemicalvariabl e s loadedon PC-Ifor 23 lake outlet sites 155 43 Resultsof ANOVA (usingGLMcommand) tote st for signi ficantdifferences in func tiona lfeeding groupabundance measureswithrespect to physical environmenta lvariablesfor 23lakeou tlet sites.Valuesunderlin e dindic ate testsre-runusing rand om iz ation.Remainingp-valueswere accepted as they would not changesignificantlyafterrandomization. . 157 44 Resultsofrandomizations(usingMean Square of Error) to testfor significant differences inFFG abundance measures with re spect to physical environmentalvariablesfor 23lakeoutl et sites .Randomizat iontests were carriedoutonly for those testswhichhad p-valuesbetween 0.015and0.300 ...158 45 Re su lt s of Fisher' s pairwise comparisons fortho se FFG abundance measures that were significantlydifferent between stud yareas(8
=
Bonavista,R ::Random Island, C::Come-by-Chance, S :: SI. John's).
Areas withsame le tter s arenot siqnificanllydifferent. ...159 46 Results of Fisher's pairwise compari sons for tho se FF Gabundance measu res that were sign ific antlydiff erent betweenlevels of disturbance (1 ::low,5:: high ).Distu rb anc elevels withsameletters are notsignif icantly
differen t. ...159
47 Re sults of Fisher'spairwisecomparis onsforabundance of gatherers which was significantlydifferentbetween stream orde rsand su bstrate types (1= mu d,2=small stone,3=wood,4
=
cobb le, 5=
boulder). Orders and su bstrate types withsame letters arenotsigni fican tlydifferent 160 48 Spearman'sRankCorrel ationCoeffic ients to evaluatethe relationbetween FFGab un dancemeasures and environmental PC-Iand PC-II(Chapter3) andchemica l variablesloaded on environmentalPC-lfor 23lakeoutle t sites 161 49 Principal compone ntsanalysis ofEPT relativeabundance data for23 lake outle t sites in Bonav ista,RandomIsland, Come-by-Chance ,and St.Joh n's, NF,duringJuly 1995,and May andJuly1996 .16250 lnterp reteucn of the princip alcomponentsanalysis ofEPTabunda nce data for 23 lakeoutlet sitesinBona vista(8),Random Islan d(R),Come-by- Chance(C).an d $1. John's (S),NF,during july 1995,and May and July
19 96. . .... _.163
51 Resultsof ANOVA(using GLMcommand)to test for signifi ca nt differen ce s in relativeabundancePC- I andPC-IIscoreswithrespect to physical environm ental variabl esfor 23lakeoutletsites .Bold valu esindica tete sts for which theresi dualsmettheassum ptio ns ofthe ANQVAmodel.
Underl ined valuesindicate te st s re-run using rand omizat ion .Remaini ngp- val u e s were accepted as they would not chang e sign ificantl y after
rand omi z atio n ..16 5
52 Results of randomizations(using Mean Squareof Error) totest for significant differencesin relati veabun dance PC-Iand PC-IIwith respe ct to physical environmentalvariables for23 lakeoutletsites. Randomizationtestswere carried outonl yfortho se testsfor whichthe residualsdidnot meet the
assumptions of theANOVAmodel. . ...166
53 Results ofFisher'spairwise compari sonsforrelative abunda ncePC-I which was signifi cantly differentbetw e enstreamorders.Orderswith sameletters
are not significantlydiffere n t. ..167
54 Resu lt s of Fisher'spairwisecomparisons for relative abundance PC-II which was sign ificantly different between study areas(B
=
Bona vis ta ,R=Random Island,C=
Come-by-Chance,S=
St. John's )andle vels of disturb ance(1=
low,5=high ). Areas and disturbancelevels with same lett ersarenot
sign ificantly different. ... .167
55 Spearman'sRank Correlation Coefficientsto evaluate therel ationbetween relative abundance PC-scoresand environmental PC-score s(Ch apt er3)for
23 lakeoutletsites. . 16 7
Prefa ce Eco- Researchproj e ct
Cold-coastalocean huma n communitiesin Newfoundlandand elsewhereare in economiccrisis due to the depletion ofgroundf ishstocks.Other contributory factors inc lu de the depletionaf minera l re sour ce s, deteriorationaf forests and te c hnolo qtc a ! change,and globalizat ionof the economy,whichhave rendered a variety ofresourceextractionindustries un economic (Ommer 1993).The purpose of the Eco-Research projectwasto examinethe sustainabilityof these cold-coastal commun ities .
Ommer(1993 ) providedan extensivereportpre senti ng objectives tha t were the n used as goals for the projectTo summarize,the objectiveof the project was to identify the central componentsrequired toachievesustainabilityforcold-coastal ocean humancommunities, such thatenvironmentalqualityinthe system couldbe balanced with economicdevelopment To assess the implicationsfor sustain a bili ty, the projectproposed toide ntifythe elementswhich haveconstitutedsustainability inthe past, and where, whenand howthose have been disturbed. Overa ll,the projectproposedto suggestguidelinesfor future policywithrespecttore gio na l sustainabi lity.Toidentify the inter -relationshipsthatunderliethe currentcrisis , inter-disciplinaryanalysiswas required. ThUS,the project brought together researchersfro m the Social,He alth , and Natura l Sciences. The central interdisc iplinaryques tionwas "Towhat extentcan human practicesand the use of
environmentalresourcesbe flexiblyorganizedto sustain cold coastal assemb lages , give n currentthre atsto the inte gr ity oftheecosys tem?"(Ommer 1993).
A goal of the natura lsciencescomponen tof the projectwas toevaluatethe effectsof natural and human -inducedenvironmentalchangeson the water- catchmentsassociatedwiththese cold-coas talhumancom mun ities (Ommer1993).
Human disturbance ofthe water-ca tchmentcan alterthe cyclingofnutri ent sin both terrestrialandmarineecosyst ems (Ommer 1993).By detenniningthose effects cau se d byloca l anthropogenicdisturbances, fut urerespons e sof the water- catchments can be predicted,and datacan be usedto assess the sustainable natureof variouseconom icuses of theenvironmen t.Studies in th is component incl uded water chem istry, lake palynology.vegetati oncove randstudi eson benthic streamflora and faun a.
Theprese nt study was included in the stream-biologyport ionofth e natur a!
science compo nentofthe project. Itinvol vedthe biomon itor ingof small water- catchments thr ough examinat ionof thecomp os itionand structure ofthe benthic macroinvertebratecommunityinrelati on toabiotic andbioti c characteristicsof the sites.Thego al was to evaluatethe use of characteristi c s ofthe benthicfau na for monitoringexistingenvironme ntalconditionsand changes in these conditions over time
Chapter 1.Overvi ewof study
1.1HIST OR YOFBIOMO NITO RING
Monitoringof freshwater systemshas become increasingly important because increasedhuman activitiessuch as agriculture,urbanlan d use and industrialactivitiestendto allerfreshwatersystemsthrough chemica lcontamination and habitat alteration. Thus,the resultsofhuman disturbances need to be assessedand controlled.
There are several methodsusedto monitorfreshwatersystems. These inclu de traditional chemicalevaluation,and biolog icalmethods using fish , plants, algae,mcromvertebrates and benthicmacroinvertebrates.Thisstudy focu sedon theuse of biologicalmethods, inparticular,macroinvertebratesas biological indicatorsofwaterquality. Fresh wa terrnacroinvertebratesare most often recommended forbiologicalmonitoring(HellaweIl1986)
Bio log ica l monitoringis "the surveillance using therespon ses ofliving organismsto determinewhetherthe environ ment is favourableto livingmaterial"
(Ro senb ergandResh1993). Thisofteninvolvestheuse of indicator speci es.An indicator species is a species (or species assemblage) thathas particula r requ irem ents for a knownset of phys icalor chemicalvariables (Johnsonet st.
1993 ). Changes in presence/absence,numbers,morpholo gy.phys io logy or behaviourofthe indica torspeciesshowwhenthegiven physica lor chemical
variables are outside its preferred range. Accordingto Rosenberg and Wiens (1976),citedby Johnsonet al. (1993),an ideal indicator should have the following characteristics: narrow and specific environmental tolerances; taxonomic soundness and easyreco gnition by thenonspecialist; cosmopolitandistribution;
high numerical abundance; low genetic and ecologicalvariability; large body size:
limitedmobilityand relatively long life history; well known ecologicalcharacteristics;
and suitability for use in laboratorystudies.
Benthic macroinvertebrates have been widelyused as biologicalindicators for assessingwater quality(e.q.,Hynes 1970;James and Eviscn 1979; Bargoset al.1990;Rosenberg and Resh 1993; Barbouret et.1996; Hauer and Lamberti 1996)_ There are several advantagesin using macroinvertebrates for biomonitoring (Rosenberg and Resh 1993; Resh et af_ 1996): they occur in all types of waters and habitats;beingsedentary,they act as continuous monitors of the water flowing over themallowing for effective spatial analyses of pollutantor disturbance effects;
they reflect episodic and cumulativepollution and habitat alteration;theyintegrate the effects of,and respond relatively quickly to environmental changes;the responses of many common species to different types of pollutionare known;the large number of species offers a widerange of responses to environmental stresses;and the taxonomyof many groupsis wellknown.
However,there are several disadvantages to using mecrotnvertebratesas biomonitors. They do notrespond directly to all types of impacts;their distribution
and abundancecanbe affected by factorsoth er than waterquality(e. g.,climatic events) ;theirabundance anddistribu tionvaryseasonally,anddispersalabi lities may carryaquatic insects intoareas where they normallydonotoccur (Rosenberg and Resh1993:Reshet af.1996)
Hellawell (1986),Rosen berg and Resh (1993)andHauer andLambert i (19 9 6) provideexcellentreviewsof thehistoryof biomonitorin g. Ind ividu al organ isms,populati onsandmultispeciescommunitiescan be usedas biomonitors. Th er e are numerous methodsavailable te analyzepopulat ionsand species assemblagesused as biornonitors. Some commonly usedunivariate analyses, often used for rapidassessment, inc lu de: richness measures (e.q.number oftaxa, number of EPT(Ephemeroptera, Plecoptera,and Trichoptera) taxa);en ume ra tions (e.g.number ofindividuals,% dominant taxa, ratioof EPT abundance to Chironomidae abundance):community diversity and similar ityin di ce s (e.q.
Shannon's (1948) Ind ex,Jaccard(19 12 ) Coefficient):biotic indices(e.q.Biotic In d ex (Hilsenhoff1987),BMWP (BiologicalMonitoringWorkingParty) Score (Wrig htet et.1988), SaprobienSystem (Kolkwitzand Marsson190 9)); and functional feedinggroup measures (e.g. ratio ofshredders to totalnumberof individuals,ratioof trophic specialiststo generalists ).Taxa richnessmeasures are most commonly used to describe macroinvertebratecommunities(Plafkinet et.
1989;Rosenberg andRes h 1993).Functionalfeedinggroup measu res are also
commonbecause they mea surea functionalaspectof themacroin vert ebrate community,ratherthanjustth e stru c ture (Ro senbe rg and Resh199 3 ).
Several studies have focu sed on Ep hemero pter a,Pleco pter a,and Tr ic ho pt era (EPT) taxaonly (e.q.Har per19 90,Bou rnaudet et.1996). The se ordersare valuable because most taxa in theseordersaresensitive to pollu tionand thereforealo ss oftaxais anin dication ofperturbation(Lenat 1988; Plafkinet at.
198 9;He fiovaa ra andvaisenen1993), and theyare ofteneasier toidentify than many other aquat ic ins ec ts (Reshand Rosen berg 1993).
Itis advantageousto use indica torspecies ratherthanchemica! and ph ys ica l measurements Chemical measurements are instantaneou sand describe conditionsthat existedwhen the samp lewas taken, whereasma croin vert eb rates ad d atemporalcompone ntbecausethey reflect past conditions.However,it is optimalto usebothapp roach es(James 1979; Rose nb ergand Re sn1993 ).
Biologicalindicatorsshow the ecologicalimbalance tha thasbeencausedand chemicalmethodsmeasurethe concentration of pollutant(s)re sponsible(James 1979 ) assumingtheyare sli llpresent at thetime ofsamp lin g.
1.2THEPR ES EN TST UDY
The presentstudy used the EPTcomponen t of the benthicmacroin verteb rate commun ityas a measur eof the hea lthof 23 lakeoutletsin sixsma ll water- catchmen ts throughou t thenorthe as ternportion ofthe Islan dof Newfoun dlan d,
Cana da The aquatic insectfaunaofNewfoundlandhas an essentiallyboreal aspect (Lar son and Coiba 1983).However,thefaunaisnaturallyimp overi shed whencompared to themainland.Larson and CoIba (1983) identified 28 species of EphemeropterainNewfoundland comparedto160 species inMaine(Burianand Gibbs 1991 )and 126in Illinois (Burk s 1975 ).Thereare 13specie sof Plecoptera in Newfou ndla nd (Larson and Coiba1983)comparedto 36 speciesin Illino is (Frison1975),20speciesin Labrador and 58 speciesin NovaScotia (Hitchcock 1974,citedby LarsonandCoiba 1983).Marshalland Larson (1982)recorded124 speciesofTrichopterain Newfoundlan d.which is low compared torich ness inthe eastemNorthAmericandeciduo usbiorne(W iggin s andMackay 1978).Peterson and Eeckhaute (1990) studiedtwostreamsin NovaScotiaandone stream in New Brunswick. More than90 speciesofTricho pterawererecorded in the New Brunsw ickstream,andin the twoNovaScotianstreamscom bined
Thenumerical reductioninfauna richnessof Newfoundland can be attribute d 10severalfactors: Newfoundland isisolatedfromthe mainland(faunal source )by saltwatercreatingan effec tive disp ersal barrier,particular lyforplecopteran taxa;
Newfoundlandhas reduced habitatdiversi ty ;andmuch of the fauna isof rel ativel y rece nt« 10,000years)post-glacial recrui tment fromthe mainland(Pres t1970, cited by Larson andCoiba1983).Inaddition ,many of these Newfoundland sp ecies are generalists,occurri ngin manytyp es of freshwaterhabitats(Larson and Coiba 1983).Thusa reduced faunaconsisting primari lyof generalists may pose problems
for biomon itoring be cause shiftsincommun itycompositionand structure may be difficult to define andinterpr et.
Therefore the aim of thisstudywas to compar ethe EPT communit iesof 23 lake outletsin northeasternNewf oundlan d and determine whether anyidentified patterns between communitiesand environmental vari ablescan be used to assess water quality in the study area given thedepauperatefauna.Thestudy examined the impact of human activityand chemica l/phys icalgradients on the composition and structureof the streamEPT communitiesof 23 Jake outlet sites. EPT communitycompositionand structurewere expected to changein a predictable mannerin relationto human disturbance .Generally, taxarichne ss and abundance were expected to below athigh levelsof humandisturbance (e. q., Benkeet at.
1981;Pitt and Bozeman 1983; Dudaatat.1982).However,areduc edlevelof disturbancemay enhanceEPTdive rsity (nu mber of taxa)an dabundance (nu m ber ofindividuals).
Broad regiona l lake -ou tl et studies compari ngvario us human im pac ts have been carriedout elsewhere on this scale(e.g. Corkum199 0; Bournaud et al.1996;
Foreetat.19 96 ). However, mo st previous studiesconcentrated onlake s, oron basins that were not interruptedby lakes,and the stud ieswerenotin areas with naturally impo verishedfauna(e.q.,Wiederholm and Eriksson 1977:Corku m 198 9, 1990;Bargaset at.1990;Whitehu rstandlindsey 1990;Barbouret at.1996;
Boumaudet et.1996) Studie son thisscale havenot beenpre viouslycarriedout inNewfou ndland.
The remainderofth is thesis is divided into fou r sections: Chapter2 descr ib e sthe chemical/physical characterist ics and human disturb anc esofsite s sampled: Chapter3 comparesand contrasts sitesbased on chemical/physical characteristicsand human disturban ces described in Chapter2;Chapter4 describes the EPTtacna ofthe 23lake outletsites and relatesthecompositionand structure offauna to the chemical/physicalcharacteristicsandhu man disturbances ofthe sites sampled(Chapter2);and Chapte r5 provides concludingremarkson th e success of the study and its relevanceto the Eco-Researchproject.
10
Chapter2.Loc ation anddescriptionofstudyareas andsites
2.1STUDYLOCATION
The naturalsciencescomponen tof theEco-Research projectfocu sedon water-catchmentsthatwere inthe areas wheresocialandhealthstudies were und erw ay and thu sin areas settledandinfl uenceddirectlyby human activity.
Therefore,allsitesselectedforsamplinghadsome degreeof humaninfluence. In order toprovid edatarelevant to the marine naturalsciencestudies,allwater- catch mentsflowedinto BonavistaHarbourorTrinit yBay. The Ecc-Research proj ect selecteddifferent areas forsampling toenablebroadcomparisonsofthe
effects ofanthro po gen ic and natur alfactorson the wholewater -catchm ent physio logy(Ommer 1993).
Twanly- three takeoutlet siteswere stud ied in fou rareasofnorth eastem Newfou ndland (Figure1). TheEco-Research studiesprimarilyfocusedontwo areas:i)the Bc nevis te Peninsu la,fromBanavista to the mouth ofTrinityBay (Figure 2),andii)theIsthmus ofth eAvalonat"Come-by-Chance(Figure 3) incl udin gboth headland andbayaspects(Ommer1993).Theoriginalproposal intendedto studythe Come-by -Chance River,which flowsintoPlace ntiaBay on the south ern shoreofNewfoundland,toevaluatetheimpact ofairborne pollutants fro m thenearbyrefine ry onfreshwate rsystems.However, asmallwater-calchme nllhat drainedintoTrinityBay wasstudied instead.Thissystemwasalsonear theCome-
11
by-Cha nceoilrefinery.Anadditionalstudy wasconducted on Random Island, Trinit y Bay(Figure 4).to associateterrestrialstudieswiththe marinenatura!
science studiesand toobtaindata fro m awater -cat ch me nt withinacommercially harvestedforest.
Originally,fourteenoutletsfrom threeweter-cetchmerasweresampled.Six sites werein the headwatersoftheBanal/islacatchment(Figure 2),four were located on theIsthmu s of the Avalon(Figure3),and four wereonRandomIslan d (Figure 4).In April 1996,seven additionalsitesin the 51.John'sarea weresample d (Figure 5),as weHas an addition al siteatBonavista and Randomlslan d _51. John's sites wer eincluded as representativesof highlydisturbed,urbanizedwater- catchments .The additionalsites atBonavis ta (8 18) and Random Island (R19) were inc ludedas furtherrepresen tatives ofrelativelyundisturbedareas.
Samplingconcentrated on lew-order streams,which by definiti on tend tobe smalland numerous.Thisallowedfor sitereplicationbased onstream size,and limited variation associatedwithstream size.Samplingwas also restrictedtotenuc outlets,withsamplesiteslocated within1to10mof wherethewatersurface breaks at the transitionfromlentic tolotte. Outlets are uniqu ebecausethey repres entthe are a wherethe biologicaland physical characteri sticsoflotic and lentc habitats merge (Genge 1985).Thefauna of outlets differs in composi tion and numericaldensity from down streamsites in that outletstend to have enha nce d benthicmacroi nvertebratefauna production,with communiti es domina ted by filter-
12
feederssuch as net-spinn ingcaocnst nes(Hyd rop sy ch id ae .Po lyce ntro pod idae, Philopotamidae)and blackflies (Si mu lii dae)(Rich ard son andMack ay1991).
Larson andCoiba (1983) provideanexten sive descriptionofNewf oundland hydrolog y,andthe follO'Ningis a summary.TheNewfoun dland dimateis cool and humid with a strongseasonal lag in temperature. Precipitation exceeds evapotran spirationacrossthe entireisland. On the AvalonPe ninsula,annual precipit at ionvaries betw een 1200 and 1700 mm. The boreallandscapeconsists ofa mixtureof barrenareas(mai nly dwarfshrub heath s, bogs, and sha llow fen s) and fore st sect ion s dominated bybalsamfir(Abiesbalsamea). Othercommon tree s indudewhile birch(Betula papyrifera),white pine(Pinus strobus).mountain alder(Ainus crispa),black spruce (Piceamariana),whitesprucetPiceegfauca )and re dma pl e(Acerrubrum).Thereare alar ge numberofbodiesof standingwater duetolowreli ef and irreg u larl y glaciated topogr aphy.Pools,bogs and fens are abundant Thus ,mostwater-catchmentsare small,ha vealow gradientovermost of theirlength and plungerapidly intothesea. Newfoundlandstreams are oligo trophicwithexpededlowbiomass ,exceptat la ke outle ts (Gen ge198 5).Most aquatic habitatshavecool temperatures,whichonly occasiona llyexceed2S"C in theshallowestpoolsand streamsand for onlyshortperio d s of time(Larsonand Coiba 1983 ). Watersare generallyacid icwi~hlowlevels ofdissolved materials.
Low pHandlim itedbuff er ing capacit yof the water mak e the aquat ic sys tems espe cia llysusce pt ibletodegrada tionbyeven small amounts of poll ution.
13
Thischapter describe s the chemicalcompositionand physical characteri stics ofth e 23lake outletsstud ie d
2.2 MAT ERIA L S ANDMETHO DS
Nin eteen environmentalvariableswere measuredat23lak eoutle t sites (Tab le 1). Elevenof these were continuouschemicalvariables induding concentrationsof various chemicals, pl-i.conductivityandtemperature .Chemical analys iswas performedby Dr. Peter Davenport.DepartmentofMine s andEnergy, Newfou ndl and.Attempts were made to measure phosphoru s, howeverleve lswere toolowto be detectedwiththe analytica lmethodsused.pHand conductivitywere measure dusing a combinedpH-eonduct ivitymeter. pH was measuredto the nearest0.5and conductivitywasmea sur ed to thene are st 1.0IJS/cm. Water temperature were measuredtothe nearest1.0 QCusing a hand-heldthermometer.
Value sfor separatesamplingdateswere averaged for each site toobtain a single measurementof temperature .
Eightcategoricalphysica lvariablesweremeasured (Table 1).Stream order wa s determinedusingtopographic maps witha scale of1:5 0, 000.Streamwidthat thesample sites was measuredto the nearest0.1m usinga measuringtape or mete rstick. Watervelocity was mea sure dusing an OttCurren t Meter heldca. 2.5 cm above the substrate.Three measuresofrevolutions/15secwere taken at each site.These wereconverte dto revolutions/minand currentvelocity wasread from
14
ca librat io nplots andrecordedto thenearest0.5 mzs. Meanwidth andmean velocityfor all samplingdales werecalcul ated andcateg ori z ed to obtainsingle velocityandwidthmeasurementsfor each siterelative toeach other(referto Table 1for categor iesofphysicalvariab les ).
Substrate type was estimated visually ,and classi fiedbased onsize (diamet er) of the predominantparticletype (T abl e 2).Three 1-m transects (unle ss site wasle ss than1 mwide)of substra tetypewere taken at eachsile .The mean ofthethree transec tswas calcu lated for each substrate type recorded and substratewascateg oriz ed as thattype wh ichaccounted forthelargestport io n of the tota l.Substrateranged frommudto boulder.A categoryof wood wasinclud ed toaccommod atesiteC14 wherethe artificialsubstrate s (se eChapte r4)were placeden branchesdue tothe slow curr en tvelo cit y andveg et atio n which choked the channel at this site . Overhangingveqeta tion. surro undingcove r,and percentagecover ofaquatic vecetetlcnwere deter mine dvisua ll y and categor ize d.
Ov erh an ging vegetation was score das presentor absent. Presentoverhanging vegetationwas takento be veqetatton alongthe bank (within1-2 m from theban k) thatoverhung the samplesite such that the sitewas partiallyDr comp le tely covered . Surrcunomqcover wastaken tc be the dominantvegeta tion inthearea visible beyond1-2 mfrom the bank.It was scoredas being open or forest. Levelof disturban cewas rankedfromlow(1)tohigh(5) and assignedto each siteba sed on the condition Df thesiterelativ eto all othersites(similartoForeet al.1996).A
15
disturbanceincluded anyknownpresent andpast.human and natural,physica l and chemical dist urba nce (e.g..urbanization,nearbyroads,road runoff,waste discharge,channelization .recreational use).A scoreof 1was assigned to a site influenced byfew-to-n one ofthese disturbances,whereas a score of5was assignedto a siteinfl ue n ced bymost orallaf these disturbances.
Continuousphysicalvariable swere categorizedto maint ainconsistency betweentheseand othercategorically measu red variables.The categ oriza tion of variablesis justifi ed becausenotenoughsite swere sam ple d to provide tren dsin mea sure s such as velocity and width. Furthermore, variablesweremea suredtwice a year only,thereforein tend ed onlytorefle ctgrossdifferences between sites.
2.3SIT EDESC RIPT IONS
Chemicaldataarepresented inTable3.All chemica lconcentra tionswere low and fell withinthe rangeof typica l valuesfor "'e althy" watersinNewf oundland (Pe ter Davenport,personalcommunication).Most siteswere onlyslight lyacidic withpH values norower than 5.6 3.Temperature s were coolto warm
Categorizedphysicaldata are providedin Table 4.Sitesrang e dfromlow (1)tomid-order(4),withmost sites being narrow,low-order streams. Substrate was dominatedby cobblesandbould ers atmost sites andmostsiteswereinforest are a s.Come- by-Chancesites werethe le ast disturbe dand St.John'ssiteswer e themost disturbed.Brief descriptio n sof study areas andsitesfollowbelow.
16 2.3.1Bonavi sta
The Bona vis ta headlandinclude sthetownatBona vis taand severalsmall surro undin gsettlements.Bona vista is arelativelylargefiShing settlement with a fishplantand whichisalsoaregion al service centre (Ommer 1993). The urbaniz ed area islimited to the mout h ofthe wate r-ce tcn ment withno current waste-w ater in pu t. butseveral partsare disturbedby abandoned railbed right-of-ways.roads and gravel pits(Colbo,personalcommunication ).Bonavistais a naturally harsh environment. ThePenin sula extend sinto the ocean andis exposed to cold,high winds.The areais a heathland and the terrainis covered by stunted forest growth (Me a de 1993). Se vensite sinthe Bonavistaarea were sampled(F igu re 2).
Site81(48°39'N.53°05'W) (Figure 6a).Loca ted in thetown of Bona vista.The outlet was ca. 600 m fromBcnavistaHarbour.Theban ksideandsurr oundin gare a were cleared and covered byheath, grassor low lyingshru bs.Aquati cvegetation was dominated by pondweed(Potamogetonnatans).Ther ewas alsoalgae onthe substrate surface.Blueflag (trisvers.CoIot)andsedges (Carex spp .)trail edintothe streamfrom the bank s.Disturb ance sre sultin gfromurb an izatio n wereve g etati on clearance and replacement by introduced specie s (Coi b a, persona l communication), road construction andsolidurban andin du strialwa ste.The pond abovethe outlet was dividedbytherailroad in the early1900s and sew agefrom the
17
hospital was dumped into one section in the past {Colbo, personnel communication}.The sitewas assigned a disturbance valueof 4.
Site82(48°37'N, 53°05'W). About 3000 m upstream of 81.The outflowin gpond is the water supply forthe town of Bonavista. The sitewas located in a stunted conifer forest of balsam fir and spruce but theoutlet itself wasdearof trees Bankside vegetationwas dominatedby bog myrtle(Myrica gale),mountainholly (Nemopanthus mucronata) and meadowsweet(Spiraea lafifa/ia). The pond was isolated from the residential area, andthe only apparent disturbance was the old railroad,abandoned in the early19805, and water mainright-ot-wa y which ran nearby.Thesite was assigned a disturbance valueof 2.
Site 83(48° 37' N, 53°05' W) (Figure 6b).Near highway230 on the outskirts of Bcnavista immediatelyupstream (ca.500 m) of B7. The streamha d been channelized a few decades beforethe present,when the sitewasin a gravel pit whichis now abandoned (Colbo, personalcommunication). Aquatic vegetation included burre ed(Sparganium angustifolium),grasses,shrubs and algae.
Bankside vegetationwas dominatedby meadowsweet, mountainalder,bog myrtle, grasses and sedges. The outletwas directlybeneath an abandoned cement bridge. The sitehad obviously been high lydisturbed in the past, but is now naturallyrevegetating as indicated by abundant 2-3 m alder regrowth and the
18
aquaticvegetati on (Colbo, personal commun ication).Thesitewas assigned a disturbance valueof 3
Sit e86(4so37'N,53~06'W).Locatedca. 150 0 m upstreamof 82on a tribu taryin anopen wetland.Thesurround ingarea ha d been highlydisturbed but is now ve getated by a shrub forest. Bankside vegetationwas dominatedby sedges, bulrush(Scirpuscyperinus) and marsh cinquefoil(Potentilfapalustn-s).The outlet had been channelizedin the past,runningund er anoldrailroad bri dg e, througha small wetland,andthen underth e highway. The channelbetween therail ro ad bridgeand highwaywas about20 m long.Sampling was carried outabout 8m downstreamfromth ebr idg e. The sitewas assigned a disturbance value of 3.
Site87(4so 37'N,53°05 'W ).About1500m upstreamof82on the mainstream.
The outlet streamran 30to 50 m betweenth e pond and a large pool. The surroundingareawa s heathlandand stunted con iferforestwithan open stream channe l. 8anksidevegetation was dominated by bog myrtle, meadowsweet, sedges,meadow rue(Thalictrum polygamum)andstun te dblackspru ce .The only apparentdisturbance was the oldgravelpit alongthetributary fromthepond(8 3).
The site was assigned a disturbance value of2.
19
Site 88(4 8 ° 37' N,53"OS'W).Ona tributaryca 170 0 m upstream of 82.The surroundi ngarea was conife rousforest, butthestreamhad been clea redand chann el izedand is now revegetated by shrubswhichsemi-overgrowthe channel.
Bankside vegetationwas dominatedby bog myrtle, meadowsweet, sedges and meadow rue.The outlet wa s ca.10 m from high way230,andthere was a woods accessroadan d abandoned railroadalo ngthe shore of the pond.Beaverhad crea teda smalldamatthe outlet.The sitewas assigneda disturbancevalueof 3.
Si te818(4S" 37' N, 53"07W).About 1300 m upstreamof 86 onitsin le t stream.
The surroundingareawa s stunted coniferousforest,but theoutlet itselfwas in an open wetland-shrubarea. Banksidevegetation was dominatedby sedges and bog myrtle with a small clumpof blackspruce tree s(ca.5-6 mtall)alsopresent.The site waslocatedabout 50m fromhighway 235,an old abandonedroadbedused for camping,and a powerline.Beaverhaddammed the outletinthe pastleav ing much decaying woodat the outle t.The site was assigned a distu rbancevalue of 3.
2.3 .2Rando mIslan d
RandomIs landis ala rge(ca.35 km long)shelteredislandin TrinityBay, surrounded by two narrowinlets. The wate r-catchmentsampled flowsinto Hick ma ns Harbour.The water-catchmentwas sheltered withina narrow,heavily forestedvalley.Most sites we rein ruralareasusedfor fore stryand limited farming.
20
Allsitesweredisturbed,but with outdirec tpoint source po liu tan t inputs (Co lbo, persona lcommun ica ti on ).Fivesiteswere sampled on RandomIsland (Figure 4).
SiteR9(4 8°06 N, 53"46'W) (Fi g ure7a ). About2500m up stre amof R13 ona trib utary. Thesurro un ding areawas a con ifero usspruce- firforest , but thestre am itselfwas open in a ditchbeside highw ay 231. The sitehad been recentl y channelized. The banks were primarilygravelandcobble justbeginningto revec etate.Arecrea tionalparkwas locatedatthe oppositeendof thepond,and theoutl et wasca. 3mfromthe highway.Thesite wasassi g ned a disturbance valueof4
SiteRl0(48QOT N,53° 4 3' W).Abo ut1300m upstre am of R11 onatributaryof R13.Theoutletwas located in a spr uce -firforestandthe strea mchanne lwas overgrown by speckled alde r (Alnus rugosa)and mountain mapl e(Acer spicatum) (ca . 4-5m tall).There weremany branchesandsmalllog sin the outlet.Bankside vegetationwas dominated by speckledalder and dogberry(Sorbus sp.) ,with some sedges and buttercups(Ranunc u{us sp.). The sitewas locatednear highway231, and a dairyfarm was locatedon the opp osite sid e of the road.Ther e was a wood- haul ingtrail throughtheoutlet,andthe sitewasuse d for recreationalactivi tiesas evidenced,for example,by a row boatbeached nearthe outlet. The site was assigneda disturbance valueof4.
21
Sit e R11(48° 0 T N, 53'44W) About 1700 m upstreamof R13.The surrounding area was coniferous forestandthe outlet was overgrown by speckled alder. There was a large accumulation of branches and tree trunksinthe stream. Surrounding vegetationwasdom in ated by 3to 5 m tallspeckled alder,with an understorey dominated by meadow rue,dogberry and goldenrod(Solidago rugosa).Thissite was within30 m of highway 231 and there were severalhouses at the opposite end of the pond.In1995the outle tflowedthrough an oldbeaver dam.This wasrebuilt by beaversin1996 floodingthe samplingsite whichwasconsequently moved furtherdownstream.The site was assigneda disturbancevalueof 2.
Site R13 (48' 06'N,53°44' W) (Figure7b). About 1000m upstream fromHrckmans Harbour.The surroundingarea was a coniferousforest. Banksidevegetation was sparse and dominatedby mountain alderand goldenrod.The sitewasIn the town of Hickman'sHarbour and was located near a smallSalvationArmyCemetery.The outletflowed throughtwo large culverts undera gravelroad to the cemetery.The site was assigned a disturbancevalueof4
Site R19(4S006'N,53" 43'W). About 1800 m upstream from Hickmans Harbouron atributary . The surroundingareawas fir-spruce-Iarc h forest andthe samplesite was overgrown by conifers. Surroundingvegetationwas dominatedby alders ,larch {Larix{aricinal,grasses and meadow rue,with the stream flow ingthrougha 10 m
22
sedgewetlandfrom thepond.Theoutletwaslocated within 30 m of a watersupply and a gravelaccess road tothetownofHickman'sHarbo ur.Therehad been some limitedrecreationaluse and somewoodcutting The site wasassigned a disturbancevalu eof 2.
2.3.3Come-by-Cha nce
The areastudiedwasarelative ly undist ur be d fenwit hsomepatchesof stunted coniferoustrees.There was no urbanizationin the area, andthe highway was200 -sao m fromthesites.There are twoin dustrial projectsin the areawhich dire ctl yandindirectlyimpact theenvironme nt.These aretheconstructionof the gravity·ba sedstructure at Bu ll Arm/Sunnysideto be used toextra ct oilfrom the offshoreHibe rn iafield6 to 7 km east of thewater-catchment,and the Come-by - ChanceOilRefi nery constructed in thelate1960' swhichis5to 6kmsouth southwe stof the water-catchment. The Oil Refinery hasbeen the object of considerableen vironmentalconcemdueto the wasteand airpollut ion(Ommer 1993).Thefour sites sampledin thi s area (Figure3)were all downwind of the oil refin ery airpoll ution.
SiteC14(4rSO'N, S3-ST W)(Figure 8a). About2000 mfrom Bull Arm.Theoutle t and surrounding area wereopen wetland withpatches of stunted coniferous forest.
The site waslocated inafenarea.There was much woodydebris intheoutle t.
23
Bankside veg etatio n wasdo m in ated bysedges,Canada burnet(Sanguisorba canadensis),bog aster(Aster nemoralis)and bog myrtle.Apartfrom theoil refinery airpolluti on, there was no apparent phy sical disturbanceinthearea ofthe pondor outlet, althoughan abandoned railwaybed layon the edge of the water-catchment Thesite wasassig ned a disturbancevalueof 1.
Site C15(47°S0 N, 53°56'W).About 500m upstreamof C17.The surrounding
area was an open wetlandwithstuntedclumps of conifers,butth e outlet it self was semi-overgrownbylow shrubs. There was extensive algal growth on the substrate.
Banksid evegetationwas dominated bylow growin gbog myrtle, mountainalder, grasses and sedges.The on ly obv io usdisturba nc e wasthe airpolluti o n of the oil refin ery.The sitewas assigned a disturbancevalueof1.
SiteC16(4JGSO'N. S3 °S6' W ).About200m upstream of C15. The -surro unding area was shrubconif erous fo re st andheath lan d,but theoutlet was semi-covered bylow alderbushes.Bankside vegetation was dominatedbylo w growing speckled alder, bo g myrtle and sedges. Thissitewas imme di a te ly under acle are d trans m is sio nline and downwindofthe oilrefine ryairpolluti on. The sitewas assigned adist urba nc e valueof 2.
24
Site C17(47°S0'N,53°5TWj(FigureBb).About 180 0 m from theseainBull Arm.
The surroundingarea was stunted conifero us fo re st and heathland. Surrounding vegetationwas dominatedby bogmyrt le,Canadaburnet and meadow rue.This sitealso had no apparentdisturbancesapartfromtheairpollutionof theoil refinery.The sitewas assigned a disturbancevalueof2.
2.3.4St.John's area
Sevensites in two water-catchmentswere sampled inParadise,MountPearl and the city of 81. Joh n's(Figure 5).Allare highly disturbedurbanizedbasins 820,821and 522 drainintothe Waterford River whichflowsinto 51. John's Harbour.823,824,825 and 826 are ona differentcatchmentthat drainsintoQuidi VidiLak e which releasesintoQuidiVidiHarbour.
Site 520(4 7"32'N,52G 5 0 ' W) (F igur e 9a). Head of the WaterfordRiver, in Paradise, ca .12000 m from 51. John'sHarbour. The surrounding area was conifer ous forest and hay fields,withtheoutlet overgrownby shrubs. Alarge dead firtree had fallenacross the stream2mabovethe samplingarea. Bankside vegetationwas dominatedby meadow rue,bog myrtleand grasses.The pond was urban ized alongaboutone quarte r of the shore lineandhay fields cove re d another quarter of the shoreline .Anabandoned railb edlay along one shoreline, ca . 100m downstream, as didhighway60 and a power corridor.Althoughthe outlet was not
25
high ly disturb ed,the pondabove thesite hadacon siderable amount of disturb an ce . The sitewas assignedadisturbance value of 5.
Site521(47'31 'N,52G 4 9 ' W).Ona tributary,inMountPearl,about 900 mfromthe main WaterfordRiveranddrainsinto the riverabout2500 m downstreamof 520. Thesurroundingareawas coniferousforest withurb an housing,buttheoutle titsel f was an open,dug channel withmowngrassalongthe banks.Therewas ca.5%
algal cover onthe substrate.Banksi de vegetationwa s dominatedby grassesand rush(Juncu s sp. ).Thissitewaslocate din anurbanlocal park with heavi lyused walkingtrails.There were houses 10mfrom the streamand pond.Thefirst 6 m ofthestream were channelizedwithconcrete The site was assigned a disturbance value of5.
Sit e $22(47 "31 'N, 52"47'W).On atribut ary,in MountPearl,about 900 mfromth e mainWaterfordRiverand drainsinto theriver about 4000m downs treamfrom where521drains intotheriver. Thedrainagefrom 522is about 7000 m upstream fromwhere the river flowsinto 51.John'sHarbour. The surround ingarea was coniferousforest, abandoned fieldsandurbanized hous ingdevelopme nt.The outietwas semi-overgrownby bushes and trees. Banksidevegetation was dominated bybalsam fir,sedges,grassesandbog myrtle.Thissitewas located behinda shopping centre and besidea cemetery ina clumpoffore st inthe Mount
26
Peart area. Thesilewas channelized atleast40 yearsago but 3Q-4Qyearold trees growalongthepresent channe l(CoIba,per son alcommuni cation).Theoutlet was isolatedfromtheresiden tial area.Thesite wasassig neda disturbancevalueof3.
Sit e 523(4J034'N,52°4 3'W)(Figure 9b). In St.John'sabou t 2800mfrom Quidi VidiLake. Theoutlet and surround ingarea werein an openurb anizedpark, locatedbetw e enmajorstreetsand governmentbuildi ngs.Therewas a sca ttering offirand shrubs in the surrounding area.Therewas extensive algalgrowthonthe
substrate. Bankside vegetation was dominatedby grassesand meadowsweet. The pond was adjacentto theuniver sitybu ildings and arecreational area. The upstream secti on was high ly channelized throu gh commercial an d urba n developments.Aside channelfrom524flowedinto thestream imme dia telyabo ve theare a sam pled.Thesitewas assigne dadisturbance valu eof5.
SiteS24(4r3S'N,S2·43'W).Ona tribut ary ,in 51. John's ,about 700mupstream of 52 3.The surr ound ingareawasconiferousforestand the outletwas semi- over g rown bytrees.The re was alsosomefallenwoodin thestrea m.8an kside vegetationwas dominated by balsamfir,bog myrt le,whitespruc e andalde rs.This sit e wasloca te dinaloca l pa rk withheavilyusedwa lk ingtrails. The pond wa s adjacentto a major st reet, housingdevelopment,govern ment buildings and institutions. The sitewasassigne d a dist urba ncevalueof5.
27
Site525(47" 36'N. 52°42'W).OnVirgin iaRiver,inSt. John's,about3000 mfrom Quidi Vidi Lake. Thesurroundingarea was conifero usforest and theoutl et was semi-overgrownby bushes .Banksidevegetationwasdominatedby mint(Me nth a sp.)and balsamfir.The pond waslocated withinaresidential area inthecity of St.
John's.Theout ietha d been dammedand channelizedsevera lyears ago{C olbc.
personal communication) . The samplesitewas in a sidecha nne lwhichstill showedact iveerosion.There was garbage (e.q., milk crate, plasticbag) in and aroundthe outletand nearbytrail.The re wasatrait cutthroughthe vegetation leadingto the outlet.The sitewas assigned a disturbancevalueof5.
Si te$26(4 7" 34' N,52"41'W).Ona small trib utaryflowingfromSignalHillinSt John'sabout 1000m from QuidiVidilake.The su rrou nd ing area was open heath but the outlet stream was in a deep channelovergrownby smalltree s and bushes Bankside vegetat ionwas dominatedby aldersand mountainash.This sitewas located belowthe Cabot Tower on SignalHill ,St. John's. The area had been deforestedand used formilita ry purposesatlea st 200yearsago (Coiba, personal communication). Th e pond served as thefirst watersupply for the city. A gravel roadra n overthe strea mca. 20 mbelow the outlet. The re was a path crossing the out let,and garbage inthe outlet (e .g.•plastic bags,road sign). The sitewa s assig neda disturbancevalueof 5.
28
59"00'W 57"00' W 53"00'W
Figure 1.Map of Newfoundlandindicatinglocation ofthefour study areas (8 = Bonavista, R= RandomIsland,C=Come-by-Chance,S = St.John's)
29
Scale 1:5 0, 0 0 0
o 1000
Figure 2.Map of 8onavista,Newfoundland, indicatinglocation of sites sampled(R.R.=Railroad).
30
OilRefinery
Figure 3.Map of theIsthmus of the Avalon,Newfoundland.indicating locationofsites samplednear Come-by-Chance,Newfoundland.
31
Figure 4.Map ofRandom Island.Newfoundland.indicatinglocation of sites sampled.
32
Seale1:.so~000 o 1000 2000M
>----+---<
Figure 5.Map of 51.John'sarea, Newfoundland,indicating location of sites sampled.
3J
Table1.Chemicaland physical characterist icsof 23lake outle tsites. their cades.andnotesonmeasurement
Measurement
Va riables Code Units Notes
Chem ical
Sulphate 504 mgfl
Magnesium Mg mgfl
Zinc Zn I-Ig/l
Alum inium AI 1-19/1
Calcium Ca mgtl
Potassium K mgtl
Sodium Na mgtl
Copper Cu j.Jgfl
pH pH
Conductivity Cond j.JS/cm
Temperature Temp 'C
Physical See
~
Stream order ORDER Four categories 1
Streamwidth (m) WIDTH Two categories 2
Substratetyp e SUBST Fivecategories 3
Mean velocity(m/ s) AVVEL Tw o categories 4
Aquaticvegetation (%) AQvEG Two categories 5
Im m ediate cover IMM COV Two categories 6
Surround ing cover SURCQ V Twocategories 7
Disturbance PHYDIS Fivecategories B
1.Stream orderwas determinedusing maps withscales of1:50,000.
Stream order rangedfrom first to fourth order.
2.Streamwidthcateg ori es were:1(3.3 m),2 (> 3.3m).
3.Subst ratetype categories were:1(rnuc ). 2(Small stone),3 (wood ).4 (cob ble), 5(boulder).
4.Average velocitycategorieswe re: 1(<50 m/s), 2 (>50 m/s) 5. Aquatic vegetationcategorieswere:1«5 %), 2(> 5 %).
6. Im med iate covercategories were:1(absen t), 2 (present) 7.Surroundingcover categorieswere:1(open), 2 (forest) 8.Disturbancecategoriesranged from1 (lOW)to 5 (high )
34
Tab le 2. Classific ation of streambed particles(adapted fromMccreacte (199 1»)
Catego ry Mod Smallstone Cobble Boulder
Particlediameter(mm )
<2 2-32 33 -256
>256
Table3.Chemical characteristicsof 23 lake outletsinBonavista, Random Island, Come-by-Chanceand 5t John's,NF,recordedduringMay andJUly 1995, and May andJuly 1996(mean values of4samplingdates)
Environmentalslte
80navista ~---Random-island
Variables B1 B2 B3 B6 B7 BS B1S R9 R10 R11 R13 R~9
S04(mgll) 38.72 23,46 54.91 3040 48.00 62.09 3,65 15.69 10.86 12.24 14.09 3.05 Mg(mgll) 1,01 0.74 0.75 0.94 0.75 0.83 0.97 0.98 1,45 1.12 0.61 0.81 Zn(~gll) 5,83 5.28 6.15 4.56 4.59 4.16 1.95 2.28 2.19 3.39 4.25 2.05 AI(~g/I) 55,63 58.13108 .38103 .13126.38 75.50 59.25 26.25 18.00 15.63 44.88 15.50
Ca(mg/I) 1.89 4.00 1.06 1.33 1.04 1.01 1.97 4,88 3.30 7.65 2.92 3.63
K(mg/I) 0,34 0.31 0.23 0,26 0.25 0.30 0.35 0,49 0.71 0.38 0.26 0.25 Na (mgfl) 12.39 8.02 6.97 8.88 7.68 6,47 13.65 9,70 9.77 6.43 3.49 3.21 Cu (1-I9/1) 3.50 4,63 7.55 7.50 6.63 5.13 1.75 4,50 5.63 2.63 2,38 1.50
pH 6.65 5,88 5.63 6,25 6.10 5.93 6.80 7,35 6.98 7.25 6,93 7,10
t:
Cone (jJS/cm)99.38 60.70 54.38 67,45 55,95 49,90 99,30 89.15 89.00 86.88 41.15 45.25 I.e.!!!PJ·C) 14.75 14.22 13,00 14.78 .gi~_14,57 13.00 13,63 14,45 14.28 13·~L...J5,OO
Table 3 continued. Chemicalcharacteristicsof 23 lake outlets.
En vi ro n m e nl aiSile~-- --·_--'-_·'---~
- --Come -by-Chance··-·- ·- - -- ·- - ·-·- - &""Joh"n-s-- ·- - - ·--- -
Variables C14 C15 C16 C17 S20 S21 S22 S23 S24 S25 S26
S04(mgtl) 58.66 32.75 28.31 24.41 7.10 12.13 4.28 7.05 19,88 9.90 6.60
Mg(mg/l) 0.60 0.66 0,62 0,64 1.19 1.29 1.23 1.03 9,20 4.28 2.29
Zn(~g/l) 12.10 3.90 3.15 3.43 4.15 22.15 4.53 17.80 5.20 9.55 4.50
AI(~g/l) 118.33 78.88 90.88 80.88 39,50 39.00 32.50 74.00 0.00 26.00 23.25
Ca(mg/l) 2.04 2.81 2,50 2.55 4,62 7.67 4.40 5.18 16,80 7.26 3.45
K(mgil) 0.21 0.26 0,25 0,26 0.75 0.95 0.48 0.93 2,10 1.08 0.80
Na (mgtl) 3.43 4,95 3,38 4.79 38,51 87.01 29.26 43.82 to9,70 53.16 50.05
Cu(~g/l) 9.17 3.25 3.63 3,63 2.25 3.75 2.00 4.00 3.00 3.00 3.50
pH 6.30 6.53 6,55 6.45 6.65 6.75 6.55 6.80 7.30 7.10 6.60
Cono(I-lSlcm) 33.80 46.38 37.38 45.70 211.50 407.50178.00 238.00 1081.00 287.50 279.00 ~ .I~!:!!E..r_~~ g7 14.40 14.82 13.68 15.00__....:!§.;~!5.50 13.50 _.__1?,50 14. ~_~_'!.:.~~.
Table 4. Physical characteristics of 23 lake outlets in Bonavista, Random Island,Come-by-Chance and SI.John's,NF,recordedduringMayand July 1995, and May and July1996,
Variables Streamorder Streamwidth(m) Substrate type Meanvelocity(mls) Aquatic vegetation(%) Immediatecover Surroundingcover
Disturba~ 4_ _~_.~~~_ _3 _2_~_ _4_ _2 4 _2.___ ~
--- - E";wr;:c;nmentaiSite-·--- --- -·--- --
Come-by-Chance St.-John's
Variab~_ _~_...£!.1~_C16 C17 S20 S21 S22 S23 S24 S25 S26 Streamorder
Streamwidth (m) Substratetype Mean velocity(mls) Aquatic vegetation(%) Immediatecover Surrounding cover Disturbance
38
a)
b)
Figure 6. Sites 81 (a) and 83 (b), Bonavista, Newfoundland.
39
a)
b)
Figure 7. SitesR9(a) and R13 (b), Random Island.Newfoundland.
40
41
a)
b)
Figure9. Sites S20 (a) and S23(b), St. John'sarea,Newfoundland.
42
Chapter 3. Co m p ar iso nof 23lake out let sites of fo u r studyareas in nort heast ern Newfound landbased onch em icalfp hysicalchar ac teristicsan d human distu rba nce.
3.1 INTRODU CTI ON
Th e conditionof a water-catchmentisinfluenced by many factors,both natural an d human. Naturally,water quality is influenced by ecological, hydrologicaland geomorphologicalprocesses such as the nature of thebedrock, the geologicalhistory andclimate of thecatchment andthebiotic communityfound in the catchment. For example.the type ofbedrock, climate,precipitationand biota present influencethe availabilityof meta lsand therate atwh ich they are leached into the water through weathering. The soil type,topography,climateand biota help determinethe amount of particulate matter presentin the water.In areas with finesubstrates,littlevegetation,andheavy rain storms,erosion of sedime ntinto the streamsandwetlands may prod ucea high in putof particul atematter. Water velocity de terminessedimenttransport,resulting in areas of erosion and deposition, whichare reflectedin the substrates foundinstreams.Water velocityis determined by reliefand water depth which reflects pastgeologicaland geomorpholog ical processes. Surroundi ngand overhangingvegetationinfluen cethe amount and type of organicmalerial entering thesystem. Othernaturaloccurrence sthatmay alterthe conditionof a water-catchmentincludefloods,storms and animal activi ty (e.g. beaver dams).Extensiveecological reviewsof riversand streams (e.g.Hyne s
43
1970;Vannoteet et.1980; Minshall 1988;Calow and Petts1992; Hauer and Lamberti 1996) provide considerable insight into natural processesth at influence the structure and function of running water systems.
Human activity also has a tremendous impact on freshwater systems. Areas withslowly weathering bedrock and poorly buffered soils tend to be more sensitive to disturbances,particularlychemical disturbances(W iederh olm 1984).Human activitymayinf luence water quality indirectlyby altering the natureof the catchment. Activities such aslogging, cleareutting,farming and channelizationmay resultin heavy erosion of slopes,siltationof streams, piling up of slash in streams, increased current velocity, elevated water temperatures and decreased alloch thonousorganic inputs (Hefiovaara andvatsanen1993). The addition of suspended particulate material may reduce plant growth by reducingthe availability of light and may alterthe substrateby fillinginterstices and smothering hard surfaces(W iederholm1984). Removal ofripar ian vegetation and channelization may change the mean temperature andthe diurnaland seasonal pattem of temperature fluctuation(Wiederholm 1984).Disturbanceof the soil and removal of vegetationdisrupt the mineral and nutrient cycles by accelerating natural weathering, mineralizationand leachingprocesses.
Land use such as farming,forestry,urbanization,industrial development and road and dam construction, resultsin contaminated runoff, which changes the physical and chemical nature of streams.Agricultureactivities may result in the
44
runoffof nutrients,pesticidesandincreased turbidity(wreoernoim1984).Industrial wastes, surf aceruno ff from pavedroad s and accidentalspills may add oilto streams (W iederholm19 84).Combustionot tossu fuel screates acid prec ip itation.
Tem perature mayalso be affected byindustrial discharges,agricultural .forestry and urbanizatio nactivities .
Tw o typesof chemical pollu tionthatresultfro m human act ivityare organic pollutio nandeutrophication. Organicpollutionmayre duc ethe availabilityof oxygen as theorganicmatter is decomposed(Hel i6 va ara and vaieenen 1993).
Theref ore organismbiomass may be reduced. Eutrophicatio nresultsfrom the addition of large quantities ofnutrients , mainly phosphorus and nitrogen compo und s. Th is causesexcess ivegrowth of algae and aquaticplants ,which pr ovidesfood and substratumfor organisms . (Heli6 va ara andvatsanen1993;
Dojlidoand Best 1993). Excessiveplantand alga lgrowthalso altersnutrient concentrations anddissolvedoxygen le vels, cansecretetoxins,affect light penetration ,and alterthe natureofthesubstratum .Plants andalgaeredu cewater movementwhich allowssedimenta tionof particula temineraland organic matter.
Eventually , the excess vegetat iondiesan dfalls to the botto mwherea build up of organicmailerincreases decompositionand createsanaerob iccondi tion s.
The following sections usedatafrom Chapter2tocompareconc entra tion s of selected chemicalvariablesbetween the studyareas,levelsof distu rbance,sites whichare open andcovered, and sites in openand forest areas .Sites are grouped
45
basedon similarphysicaland chemical characteristics using multivari at estatistics . All statistica lanalysiswere performed using Minitab Releas e 11. Sites are hypothe si z edto differ significantlybasedon level of disturbanceand associated chemi calcomposition.St John'ssite s are nypotnesuecto differsig n ifi ca ntly from rema in in gsite s in terms of chemicalcomposition,whichtends to be inf luencedby distu rb an ce.
3.2AN ALYTICA L METHOD S 3.2.1Univaria teAnalysi s
TheGene ralLinea rMode l(Gl M)wasusedtoperformModelIIAnalysis of Variance (ANOVA) to test for significant differencesin thevalu e sofeach chemical variablebetwee n study areas, levels of disturbance,open and coveredoutlets ,and outlets in open and forest areas (Chapter 2).ANQVAis used to testforsignificant diffe re nces betweentwo or more sam plemeans using variance sto measurethe differencesbetween means (SakalandRoh lf 1995).ANQVAis commonlyused to ana lyse dat afrom benthic studi es(Ro sen berg and Resh1993).
Foreach test, residualswere examin ed 10dete rmine wtleth ertheymet the assumptions of theANQV A model. Whe nthe residual s didnotmeetthe assumptions of the ANOVAmodel,randomiz ation tests were performed .Unlike ANOVA,randomizati onrequiresnoassump tions of theerror distrib uti on,except for ran dom selection (Manly1991 ).
