xv international symposium on chironomidae for gislason and gardarsson.pdf · proceedings of the xv...

XV International Symposium

on Chironomidae

Edited by

Leonard C Ferrington Jr

The University of Minnesota Minneapolis Minnesota


on Chironomidae

Edited by



ii

A contribution by the

Chironomidae Research Group Department of Entomology

at the University of Minnesota

Cover and Title Page Illustrations by Leonard C Ferrington Jr (Editor)

The Editor would like to acknowledge and thank the Academy of Natural Sciences of Philadelphia for

permission to use in modified form the image of an adult male tanypod from the cover of Dr Selwin S Robackrsquos (1971) publication ldquoThe Adults of the SubfamilyTanypodinae (=Pelopiinae) in North

America (Diptera Chironomidae) as the archetype for the conference logo Please note however

that in the process of modifying the image it has been transformed into a species of Prodiamesinae

Copyright

copy 2010 by Leonard C Ferrington Jr

All rights reserved No part of this publication may be reproduced stored in a computerized system

or published or distributed in any form or manner (including electronic mechanical reprographic or photographic without prior written permission from the Editor

Literature Citation

Text

Ferrington L C Jr (editor) 2010 Proceedings of the XV International Symposium on Chironomidae Chironomidae Research Group University of Minnesota Saint Paul

Minnesota 385 pp + viii

Article

Wuelker W 2010 The role of chromosomes in chironomid systematics ecology and phylogeny pp 1-13 In Ferrington L C Jr (ed) Proceedings of the XV International

Symposium on Chironomidae Chironomidae Research Group University of Minnesota

Saint Paul Minnesota 385 pp + viii

Credits

Special Thanks to Ms Claire Serieyssol Bleser

Publications Coordinator

Proceedings of the XV International Symposium on Chironomidae Department of Entomology University of Minnesota

219 Hodson Hall 1980 Foley Hall

Saint Paul Minnesota 55108-6125

iii

iv

The XV International Symposium on Chironomidae was convened August 12-15 2003 on the Minneapolis Campus of the University of Minnesota Contributed papers sessions and poster displays were held in the Basic Science and Biomedical Engineering Building on Church Street in Minneapolis Eighty-two delegates registered for the symposium and seventeen accompanying persons including spouses and several children attended social events The program included the traditional Honorary Thienemann Lecture followed by Seventy-five platform and poster presentations The Symposium Program giving a complete list of all scheduled presentations and Symposium activities is included at the end of the proceedings Delegates arriving early for the symposium participated in a day long pre-meeting social event and

several people stayed after the symposium to participate in an optional post-meeting excursion to the headwaters of the Mississippi River Northern Minnesota and the North Shore of Lake Superior on August 15-17 Two Committees worked hard to make the conference a success and to ensure the visits by delegates accompanying spouses children and others to Minnesota were pleasant The Program Committee consisting of Leonard Ferrington Barbara Hayford Susan Gresens James Kennedy Will Bouchard Byron Karns Dan Hansen and Henrique Paprocki was responsible for the ldquoSciencerdquo of the meeting The Local Arrangements Committee was largely responsible for developing and coordinating the ldquoSocialrdquo aspects of the meeting and consisted of Dean Hansen Leonard Ferrington David Maschwitz Jim Shaver Will Bouchard and Dan Hansen Generous support for the conference was provided by the Department of Entomology at the University of Minnesota Emmons amp Olivier Resources an environmental engineering firm specializing in stormwater management EcoAnalysts Inc an environmental consulting company specializing in invertebrate monitoring and The Mill Stream Association a local citizen-based organization concerned with water quality in eastern Minnesota

An Evening Mixer was held from 700 until 930 PM on Tuesday Evening 12 August 2003 at the Weisman Art Museum located on the Minneapolis Campus of the University of Minnesota near the conference venue Light hors drsquo oeuvres and beverages were provided Entertainment consisted of a lecture and slide show by Dr Dean Hansen on Underwater Photography of Aquatic Insects Refreshments for this mixer and all other social events were

donated by EcoAnalysts Inc

v

On Thursday 14 August 2003 delegates were treated to an evening buffet dinner aboard the Betsy Northrup River Boat while touring the Mississippi River near Minneapolis The evening dinner and riverboat cruise lasted 3 hours and was attended by all registered delegates and their accompanying guests The River Boat Cruise was partially underwritten

with a generous contribution by Emmons amp Olivier Resources

Our symposium ended with a business meeting during which we selected the venue for the XVI International Symposium in 2006 The discussion was led by Ole Saeligther The Czech Republic China and Madeira were offered as potential venues A decision was made to accept Madeira as the venue for the XVI Symposium on Chironomidae in 2006 Thirty-five of the presentationsposters given during the symposium and one additional contributed paper were submitted for publication in this proceedings All manuscripts received technical suggestions by at least two anonymous reviewers along with some text editing and formatting to standardize page size and font Authors were asked to conform to formatting instructions for the Journal of the Kansas Entomological Society however final

punctuation and style for text citations and references were dictated by the preferences of individual authors The full unabridged text of the Thienemann Honorary Lecture is included and has been posted on-line The remaining papers have been divided into four general categories by subject Distribution Life Histories and Ecology (20 papers) Cytogenetics and Molecular Biology (four papers) Taxonomy (eight papers) and Special Featured Contributions (three papers) The Program Committee would like to thank the Academy of Natural Sciences of Philadelphia for kindly providing the collections of reprints of Dr Selwin S Roback that were used as student prizes for best research papers during the Symposium We would especially like to acknowledge and thank Dr Jon Gelhaus for providing the reprints and for his help in developing the concept for the awards We would also like to thank the Academy for permission to use in modified form the image from the cover of Dr Robackrsquos (1971) publication ldquoThe Adults of the SubfamilyTanypodinae (=Pelopiinae) in North America (Diptera Chironomidae)rdquo as the archetype for our logo Please note however that in the

process of modifying the image it has been transformed into a species of Prodiamesinae


A contribution of the

vi

PROCEEDINGS OF THE XV INTERNATIONAL SYMPOSIUM

ON CHIRONOMIDAE

Table of Contents

The Thienemann Honorary Lecture THE ROLE OF CHROMOSOMES IN CHIRONOMID SYSTEMATICS ECOLOGY AND PHYLOGENY WOLFGANG F WUELKERhelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip1

DISTRIBUTION LIFE HISTORIES AND ECOLOGY Production and Life Cycle of Chironomus major (Diptera Chironomidae) in Kentucky Lake USA PINAR BALCI DAVID S WHITE and GARY RICEhelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip14 Longevities and Survivorship Patterns of Adult Diamesa mendotae a Winter-Active Chironomidae LEONARD C FERRINGTON Jr BYRON KARNS and R WILL BOUCHARD Jr helliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip22 A New Technique For Using Chironomid (Diptera) Remains in Paleoclimate Research DONNA R FRANCIS MATTHEW J WOOLLER GIFFORD H MILLER IAN R WALKER MARILYN L FOGEL and ALEXANDER P WOLFEhelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip30 Intersex in the Terrestrial Chironomid Bryophenocladius illimbatus JAN FROUZhelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip37 Terrestrial Chironomids in Disturbed Habitats JAN FROUZhelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip41 The Production of Chironomids and Blackflies in a Subarctic River GIacuteSLI MAacuteR GIacuteSLASON and ARNTHOR GARDARSSONhelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip45 Chironomid Species Assemblages of Streams Draining Areas of Serpentine Versus Non-serpentine Bedrock SUSAN E GRESENS and LEONARD C FERRINGTON Jr helliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip55 The Impact of Bank Protection Work on the Chironomid Fauna (Diptera Chironomidae) in the Middle Reaches of the Chikuma River in Central Japan KIMIO HIRABAYASHI and MASARU YAMAMOTOhelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip70 Relationships of Chironomidae with Hydroperiod in Eastern Everglades National Park RICHARD E JACOBSEN and SUE A PERRYhelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip78 Chironomid Assemblages in Different Alpine Stream Types VALERIA LENCIONI and BRUNO ROSSAROhelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip95 Definition and Assignment of Indicator Weights to Different Chironomid Species LAURA MARZIALI CARLOTTA CASELEGMO VALERIA LENCIONI and BRUNO ROSSAROhelliphelliphelliphelliphellip103

vii

DISTRIBUTION LIFE HISTORIES AND ECOLOGY continued The Chironomidae (Diptera) of the Taro River (Italy) LAURA MARZIALI CARLOTTA CASELEGNO GIORGIO HANOZET GIUSEPPE PARENTI MATILDE FORCELLA ELISAl BERRA ROBERTO GIACCHINI and BRUNO ROSSAROhelliphelliphelliphelliphelliphelliphelliphellip109 Ontogenic Changes in the Diet of Lentic Chironomid Larvae with Emphasis of the First Instar Larvae J S OacuteLAFSSONhelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip118 Chironomidae (Diptera) Living in Freshwater Sponges (Porifera) in Brazil FABIO DE OLIVEIRA ROQUE SUSANA TRIVINHO-STRIXINO SHEYLA R M COUCEIRO NEUSA HAMADA and CECILIA VOLKMER-RIBEIROhelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip131 Lake Reference State Deduced From Chironomid Pupal Skin Data LESLIE P RUSE and STEPHEN J BROOKShelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip140 Biodiversity of Chironomidae Larvae (Diptera) and Oligochaeta (Annelida) in Snyderrsquos Branch Creek (Salem Virginia United States of America) Testing for Ecological Discontinuities JORGE A SANTIAGO-BLAY BRIAN C WILSON and CHRISTINE E TAYLORhelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip156 Chironomidae of a Floodplain Pond in Coacuterdoba Argentina JOHN B STAHLhelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip168 Finding the Best Measures of Chironomid Community Response to Disturbance in the Upper Trinity River Basin North Central Texas JAYNIE M STEPHENSON and JAMES H KENNEDYhelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip174 New Records and Range Extensions for Several Genera of Chironomidae From Lake Superior KEVIN T STROOM KURT SCHMUDE JIM SNITGEN STEPHEN J LOZANO TIMOTHY CORRY and JILL V SCHAROLDhelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip184 Chironomidae of the Kenai River From Collections of Pupal Exuviae DAVID C WARTINBEEhelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip196

CYTOGENETICS AND MOLECULAR BIOLOGY Chromosomal Evolution of Nearctic and Palearctic Chironomus Species (Diptera Chironomidae) IYA I KIKNADZE MALCOLM G BUTLER LARISSA I GUNDERINA ALBINA G ISTOMINA VLADIMIR D GUSEV and LUBOV A NEMYTIKOVAhelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip203 Preliminary Physical Maps of the Chironomus Genome with a Focus on Genes Potentially Involved in Response to Heavy Metals JON MARTIN HENRY CHUNG THAVARNALAR BALAFRISHNAN and CHARLES ROBINhelliphelliphelliphelliphelliphellip222 Cytogenetic Biomarkers in Chironomus riparius Mg (Diptera) as Indicators of Heavy Metal Pollution PARASKEVA MICHAILOVA NINEL PETROVA GABRIELLA SELLA STEFANO BOVERA KEITH WHITE and LILIAN RARNELLAhelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip235 The Polytene Chromosomes of Kiefferulus (Nilodorum) ldquospecies Yanumardquo (Diptera Chironomidae) SUMITRA SAXENAhelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip243

viii

TAXONOMY

The Immature Stages of Chasmatonotus unimaculatus Loew (Diptera Chironomidae Orthocladiinae) with Notes on their Habitat MICHAEL J BOLTON and RICHARD E JACOBSENhelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip255 A new species of Paratanytarsus Thienemann and Bause (Diptera Chironomidae) with unusual larval and adult male morphology MICHAEL J BOLTON TORBJOslashRN EKREM JAMES E SUBLETTE and MARY F SUBLETTEhelliphelliphelliphelliphellip262 Description of the Immature Stages and Adult Female of Neostempellina reissi Caldwell (Diptera Chironomidae) BROUGHTON A CALDWELL ROBERT W BODE and ALEXANDER J SMITHhelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip272 A New Genus From Bromeliads in Florida and Brazil (Diptera Chironomidae Orthocladiinae) J H EPLERhelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip285 Can Gonostylus Heel of Procladius (Holotanypus) be a Key Character to Identify Species TADASHI KOBAYASHIhelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip294 Two New Brazilian Species OF Axarus Roback 1980 (Diptera Chironomidae Chironominae) HUMBERTO F MENDES AND TROND ANDERSONhelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip302 A New Genus of Orthocladiinae from Patagonia and South Chile (Diptera Chironomidae) O A SAEligTHER and T ANDERSENhelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip311 The Female of Bethbilbeckia floridensis Fittkau 1988 with A Review of the Genus (Diptera Chironomidae) CHARLES N WATSON Jrhelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip334

SPECIAL FEATURED CONTRIBUTIONS The History Present Status and Future Prospects of Chironomidae Research in China XINHUA WANG RUILEI ZHANG YUHONG GUO HONGQU TANG ZHEN LIU and CHUNCAI YANhellip342 The Association of Chironomids and Vibrio cholerae (The First Three Years of Research) MEIR BROZA MALKA HALPERN HANAN GANCZ and YECHEZKEL KASHIhelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip357 The General Bibliography of the Chironomidae (Diptera) ODWIN HOFFRICHTERhelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip368

SYMPOSIUM PROGRAMhelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip371

Proceedings of the XV International Symposium on Chironomidae pp 45-54

Edited by Leonard C Ferrington Jr (2010)

The Production of Chironomids and Blackflies in a Subarctic River

GIacuteSLI MAacuteR GIacuteSLASON and ARNTHOR GARDARSSON Institute of Biology University of Iceland Askja IS-101 Reykjavik

ABSTRACT In 1978-1985 in the River Laxaacute N-Iceland the production of Orthocladiinae

the dominant subfamily of Chironomidae was estimated by the average cohort method at three stations at 2 6 and 24 km downstream from the outlet of Lake Myacutevatn At two upstream

stations population levels of aquatic insects have been monitored with window traps since

1977 Dominating Orthocladiinae species were Eukiefferiella minor E claripennis Orthocladius consobrinus and O oblidens The blackfly Simulium vittatum accounted for up

to 90 of all insects caught in the traps

Production of Chironomidae was 8-35 g AFDW m-2

y-1

5-47 of the combined production of chironomids and blackflies at the outlet of Lake Myacutevatn and 9-27 g AFDW m

-2y

-1 at the

sampling stations 5 and 24 km downstream Production of S vittatum was 27-599 g AFDW

m-2

y-1 53-95 of the combined production at 2 km from the outlet and 13-69 g AFDW m

-2y

-1

or 43-86 of the production at the two other stations

We suggest that populations of Chironomidae in the river are dependent on benthic algal production which explains the relative stability in the populations over the past 26 years in

comparison with the larval blackfly population which feeds on drifting FPOM and reflected

changes occurring in the phytoplankton production in Lake Myacutevatn

INTRODUCTION

A critical step in understanding food webs and trophic dynamics of communities is qualifying the role of the primary consumers Chironomidae tend to dominate in arctic and alpine regions (Petersen et

al 1995) and most rivers in Iceland except lake outlets (Giacuteslason et al 1998) but relatively few

studies of annual production have been conducted Chironomidae production is known from a few

rivers in the temperate region (see Armitage et al 1995 Benke 1998 Wright and Smock 2001) and in the Norwegian highlands (Aagard et al 1997)

The River Laxaacute N-Iceland provides a good opportunity to study trophic relationships Discharge measurements began in 1950 and other major physical and chemical variables have been monitored

since 1971 (Giacuteslason 1994) Aquatic insects have been monitored from 1977 and waterfowl since

1975 (See Giacuteslason 1994 Gardarsson and Einarsson 2004) Discharge and nutrient input into the river is relatively stable from year to year However fine particulate organic matter (FPOM)

fluctuates on a year to year basis and the production of the blackfly Simulium vittatum Zett has

shown up to an order of magnitude difference in minimum and maximum annual production

(Giacuteslason and Gardarsson 1988) Year to year changes in the annual catch of brown trout (Salmo trutta L) (Giacuteslason et al 2002) and population dynamics of Barrowrsquos goldeneye (Bucephala

islandica (Gmelin)) and the harlequin duck (Histrionicus histrionicus (L)) reflect changes in the

abundance of S vittatum (Einarsson et al in press)

The aim of this study is to evaluate the contribution of Chironomidae production to secondary

production in a subarctic lake outlet

46

SAMPLING SITES The Laxaacute is a lake-fed river in the volcanic zone of North Iceland (Figure 1) It flows over a bed of lava rock formed by a large eruption about 2300 years BP (Thoacuterarinsson 1979) River Laxaacute is the

outlet of L Myacutevatn (65 35rsquoN 17 00rsquoW) 278 m asl with mean flow of 33m3s

-1 (Figure 1) Rivers

Kraacutekaacute and Sortulaekur add a further 7 m3s

-1 and 1 m

3s

-1 respectively to the discharge near the outlet

(Oacutelafsson 1979a Rist 1979) The discharge of the River Laxaacute is stable throughout the year and

almost no floods occur (Rist 1979) The major ions remain stable through the year due to the even subterranean flow of water into Lake Myacutevatn (Oacutelafsson 1979b)

The sampling sites Midkviacutesl Helluvad and Thveraacute were selected as representative of the 35

km long upper part of the river above the

Laxargljuacutefur canyon where current velocity and

waterfalls make the river impassable to migrating fish However the upper part has a

large landlocked stock of brown trout (Giacuteslason

et al 2002) feeding on the benthic invertebrates (Steingriacutemsson and Giacuteslason

2002) Midkviacutesl is one of three channels that

constitutes the outlet Helluvad is 5 km below

the outlet and Thveraacute is 24 km downstream from the lake The upper part of the river Laxaacute and its

animal communities are described by Giacuteslason

(1994)

METHODS

In 1978-80 and 1984-85 benthic samples were

taken 2-3 times a month from May to September and once in October and January In 1977 and

1981-85 samples were taken monthly from May

to October and in 1982 once in January Benthic samples were taken by removing lava rocks

from the bottom holding a net (mesh size 70

m) downstream and collecting dislodged animals (Giacuteslason 1985 Giacuteslason and

Gardarsson 1988)

Figure 1 Map of Lake Myacutevatn and River Laxaacute

Five rocks were examined from each collection Each rock was outlined on graph paper in the same

position as it had on the bottom The resulting area was used to calculate numbers and biomass per m2 In

addition to benthic samples both qualitative and quantitative seston samples were taken The processing

of benthic and seston samples have been described earlier (Giacuteslason 1985)

Production of Chironomidae and S vittatum were estimated by the size frequency method (Hynes and Coleman 1968 Hamilton 1969) S vittatum larvae were grouped into 1 mm length classes to enable

separation of generations 100-400 larvae in each length class were dried for 24 hours at 60 C and

weighed on an analytical balance The larvae were incinerated for 80 minutes at 600 C and weighed again The length of 30 Chironomidae larvae was measured their diameter was measured at 4 points near

their ends and at 13 and 23 of their lengths respectively Their weight was estimated from their volume

and natural density (weight = r

2length

105 where r is the mean radius of the larva and 105 its specific

47

gravity) and the ash free dry weight was estimated the same as for S vittatum 122 of wet weight

(Giacuteslason and Gardarsson 1988) The relationship between ash free dry weight and length of Chironomidae larvae was y = 00056x

31898 (r= 0974 plt001 n=30) The regression of weight on length

of S vittatum larvae was y = 00010x29814

(x = mean length of class in mm y = mean weight in mg ash

free dry weight r2= 0996 plt001 n=10)

The ash free dry weight was estimated for the mid class of each length group (05 15 etc) and for class

limits (10 20 etc) by regression equations From the length distribution from each sample the size

frequency method was used as described by Hynes and Coleman (1968) with the modifications of

Hamilton (1969) to estimate production P = i (nj-nj+1)wj+12 where i is the number of length classes nj and nj+1 number in length classes j and j+1

Window traps (Joacutensson et al 1986) were operated on a bridge crossing the outlet (Dragsey) and on a

water level gauging station at Helluvad (5 km downstream) each year from 1977 on (fig 1) The traps were made of transparent acrylate with windows (20x20cm) facing upstream and downstream Insects

caught in the traps were preserved and recovered every 10-15 days from early May to October

The yearly FPOM and production estimates were made from samples obtained from 10 June to 9 June the following year at Midkviacutesl and Helluvad and from 1 July to 30 June for Thveraacute reflecting the start of new

generations of midges Window trap catches are expressed as cumulative catches from 20 July to 19 July

the following year representing the emergence of the summer cohort and winter cohort of each

generation of S vittatum (Giacuteslason 1985)

Water temperature was measured continuously with a thermometer submerged at the outlet (cf Oacutelafsson

1979a)

Table 1 Proportional composition () of benthic invertebrates in the River Laxaacute based on all benthic samples from 1978-1985

TAXON SAMPLE SITES

Midkviacutesl Helluvad Thveraacute

Chironomidae

Orthocladiinae 34 44 42

Other Chironomidae 1 4 2

Simuliidae

Simulium vittatum 63 47 53

Other invertebrates 2 5 3

Total 100 100 100

RESULTS

The proportion of Diptera by numbers in the benthic samples in the River Laxaacute was 95-98 Among Diptera the average proportion of Chironomidae in the benthos during the study period was 35 48

and 42 at Midkviacutesl Helluvad and Thveraacute respectively (Table 1) Orthocladiinae dominated the

Chironomidae community and other subfamilies were 1-4 of the total benthos S vittatum contributed 47-63 to the total numbers in the benthic samples The average annual densities of Chironomidae larvae

were 136000 m-2

at Midkvisl 49000 m-2 at Helluvad and 96000 m

-2 at Thveraacute (figure 2) Biomass

showed similar differences between the sampling stations (figure 3) The densities and biomass of

Chironomidae did not change much over the study period although blackflies increased 4-7 fold in numbers and biomass from 1979-80 to 1984-85 (figures 2-3 Table 2)

48

The production of chironomid larvae and pupae was between 8 - 34 g AFDW m-2

y-1

at Midkviacutesl 10 - 17 g

AFDW m-2

y-1

at Helluvad and Thveraacute (figure 4 Table 2) There were much greater fluctuations in blackfly production ranging from 27 to 599 g AFDW m

-2y

-1 at Midkviacutesl and 12 - 90 g AFDW m

-2y

-1 at

Helluvad and Thveraacute The turnover rate (PB) for Chironomidae was 34-80 and 22 - 90 for S vittatum

at all sampling sites (Table 2) indicating one and two life cycles per year among the dominant

chironomid species and S vittatum

Table 2 Biomass (g-afdw m-2

) and production (g-afdw m-2

y-1) of Chironomidae and S vittatum

in the R Laxaacute estimated with the size frequency method (Hynes and Coleman 1968) and

later modifications by Hamilton (1969) Data missing for Chironomidae at Midkvisl

and Helluvad from 1981-82 to 1983-84 and at Thveraacute from 1980-81 to 1984-85

Study Year 78-79 79-80 80-81 81-82 82-83 83-84 84-85

Chironomidae

Midkvisl (outlet) P 267 233 76 --- --- --- 347

B 46 38 11 --- --- --- 43

PB 58 62 66 --- --- --- 80

Helluvad (5 km) P 102 93 175 --- --- --- 127

B 22 25 24 --- --- --- 27

PB 47 37 72 --- --- --- 48

Thvera (24 km) P 97 173 --- --- --- --- ---

B 29 30 --- --- --- --- ---

PB 34 58 --- --- --- --- ---

Simulium vittatum

Midkvisl (outlet) P 532 272 1006 571 544 513 5990

B 152 98 193 109 202 231 666

PB 35 28 52 53 27 22 90

Helluvad (5 km) P 211 125 132 212 212 189 796

B 45 32 25 42 136 65 220

PB 47 39 53 50 16 29 36

Thvera (24 km) P 247 239 251 467 692 668 897

B 42 66 34 127 132 120 140

PB 59 36 75 37 53 56 64

Window trap catches of Chironomidae were small at all stations from 1977 to 2001 and for the blackfly S

vittatum it showed a considerable increase during 1984 and 1985 when the production of S vittatum peaked (figure 5) No relationship was found between the chironomid production and window trap

catches of adults from the river (r = -0351 n = 8) but correlation between the production of Svittatum

and the subsequent number of adults from the same cohorts was highly significant (Giacuteslason and

Gardarsson 1988)

49

DISCUSSION

The Chironomidae production of the River Laxaacute was between 8 and 35 g AFDW m-2

y-1 a production

range for moderate to high production in lotic habitats as defined by Armitage et al (1995) where

extremely high production was above 32g DW m-2

y-1

(highest value known was 77 g DW m-2

y-1

) Annual

production of chironomids in a lowland stream in Denmark was estimated 13 g DW-2

y-1

(Lindegaard and

Mortensen 1988) Similar values were reported for two lowland streams in Poland (Grzybkowska 1989) Benke (1998) observed a similar range for the most productive genera of filtering collectors of

Chironomidae on snag surfaces in a Costal Plain river in south-eastern USA and the total production of

Chironomidae was 65 g DW m-2

y-1

Total production of Chironomidae in the sediment of a headwater of a Coastal Plain river was 39-42 g DW m

-2y

-1 (Wright and Smock 2001) However the production in

Midkvisl (outlet)

Density (

nos m

-2)

0

50000

100000

150000

200000

250000

300000

1200000 Chironomidae

S vittatum

Thvera (24 km)

1978 1979 1980 1981 1982 1983 1984 1985

Density (

nos m

-2)

0

50000

100000

150000

200000

250000

300000

1200000

Helluvad (5 km)

Density (

nos m

-2)

0

50000

100000

150000

200000

250000

300000

1200000

Figure 2 Densities of Chironomidae and S vittatum larvae in the River Laxaacute

50

Laxa was an order of magnitude larger than the macroinvertebrate production in a pristine Norwegian

highland stream (Aagaard et al 2001) In the Laxaacute the production of Chironomidae was mainly by Orthocladiinae the most common species were Eukiefferiella minor (Edwards) E claripennis

(Lundbeck) Orthocladius consobrinus (Holmgren) and O oblidens (Walker) (Giacuteslason et al 1995a b)

Midkvisl (outlet)

Bio

ma

ss (

g a

fdw

m-2

)

0

10

20

3060

80Chironomidae

S vittatum

Thvera (24 km)

78-79 79-80 80-81 81-82 82-83 83-84 84-85

Bio

ma

ss (

g a

fdw

m-2

)

0

10

20

3060

80

Helluvad (5 km)

Bio

ma

ss (

g a

fdw

m-2

)

0

10

20

3060

80

Figure 3 Biomass of Chironomidae and S vittatum Data missing for Chironomidae at

Midkvisl and Helluvad from 1981-82 to 1983-84 and at Thveraacute from 1980-81 to 1984-85

Preliminary studies on the food of Chironomidae indicate that they were feeding on epilithic algae on the

river bottom (Giacuteslason 1994) The food of S vittatum larvae was drifting algae and detritus originating in

the Lake Myacutevatn (Giacuteslason and Joacutehannsson 1991) The population of the dominating benthic

51

invertebrate the blackfly S vittatum reflects changes in Lake Myacutevatn Production was significantly

associated with temperature expressed as degree days and FPOM (Giacuteslason and Gardarsson 1988) and significant relationships are found between the summer cohort of S vittatum and Anabaena flos-aquae

(Giacuteslason 1994) Numbers of S vittatum in the window traps were correlated with the production of the

corresponding generation (Giacuteslason and Gardarsson 1988)

Midkvisl (outlet)P

rod

uctio

n (

g a

fdw

m-2

yr-1

)

0

25

50

75

100

600 Chironomidae

S vittatum

Thvera (24 km)

78-79 79-80 80-81 81-82 82-83 83-84 84-85

Pro

du

ctio

n (

g a

fdw

m-2

yr-1

)

0

25

50

75

100

600

Helluvad (5 km)

Pro

du

ctio

n (

g a

fdw

m-2

yr-1

)

0

25

50

75

100

600

Figure 4 Production of Chironomidae and S vittatum Data missing for Chironomidae at Midkvisl and Helluvad from 1981-82 to 1983-84 and at Thveraacute from 1980-81 to 1984-85

Chironomid production did not change much from year to year (figure 4) No relationship between chironomid production in the river and catches in the window traps (r = -0351 n = 8) might indicate that

either the annual difference is so small that no relationship can be detected or the small changes in

52

window trap catches and production observed in the chironomids compared with the blackflies may be of

more stochastic nature than changes in environmental parameters especially food supply No relationship was observed between the window trap catches of chironomids and blackflies (r=008 n=50) This

suggests that they do not share the same resources

Population fluctuations of chironomids in the River Laxaacute and Lake Myacutevatn were not related except for E minor and O consobrinus (Gardarsson et al 2004) Changes in chironomid species were not related to

drifting FPOM except for E minor (p = 002) (Gardarsson et al 1995) In Lake Myacutevatn the dominant

chironomid species Tanytarsus gracilentus (Holmgren) had population cycles of over four orders of magnitude driven by consumer-resource interactions (Einarsson et al 2002) In the River Laxaacute the

changes in total numbers of catches of chironomids were within one order of magnitude (figure 5)

Chironomidae

Num

ber

0

50000

100000

150000

Dragsey(outlet)

Helluvad (5km)

S vittatum

19

76

19

78

19

80

19

82

19

84

19

86

19

88

19

90

19

92

19

94

19

96

19

98

20

00

20

02

20

04

Num

ber

0

100000

200000

300000

400000

Dragsey (outlet)

Helluvad (5 km)

Figure 5 Window trap catches of Chironomidae and S vittatum at the outlet and at Helluvad (5 km downstream) Note that the scales on the y-axes are

not the same for Chironomidae and S vittatum

Although production of the Chironomidae is moderate to high compared with lotic habitats in the

temperate zone (Armitage et al 1995) its importance in the food web depends on changes in S vittatum

production chironomids becoming relatively more important in years with low S vittatum production In the brown trout in 1992 chironomids were about 22 of the diet (Steingriacutemsson and Giacuteslason 2002) or

53

half of their contribution to benthic densities During periods of emergence of S vittatum the proportion

of Chrionomidae increased but at the same time the total volume of trout stomach contents decreased (Giacuteslason and Steingriacutemsson 2004) The duckling production of harlequin duck and the numbers of

Barrowrsquos goldeneye responded to changes in S vittatum numbers but not numbers of Chironomidae

(Einarsson et al 2006) Chironomid production in the River Laxaacute is high compared with rivers of similar

latitude but S vittatum plays a more significant role as food for vertebrate species in the River Laxaacute ecosystem than the Chironomidae The role of chironomids as food for invertebrate predators is still not

understood and needs further study

ACKNOWLEDGMENTS

We thank our colleagues at the Institute of Biology University of Iceland for their support and advice during the study We are especially indebted to Adalbjoumlrg Erlendsdoacutettir Dr Kristiacuten Bergsteinssdoacutettir

Gudruacuten Laacuterusdoacutettir and Iris Hansen for doing the measurements and preparing the data on spreadsheets

We thank Dr Joacuten S Oacutelafsson for drawing the final diagrams and Dr Aacuterni Einarsson for reading the

manuscript The Myacutevatn Research Station provided logistics and support during field work This study was financed by the Research Fund of the University of Iceland and the Icelandic Science Foundation

REFERENCES

Aagaard K JO Solem T Nost amp O Hanssen 1997 The macrobenthos of the pristine stream Skiftesaa

Hoylandet Norway Hydrobiologia 34881-94 Armitage P PS Cranston amp LCV Pinder 1995 The Chironomidae Biology and ecology of non-biting

midges Chapman amp Hall London

Benke AC 1998 Production dynamics of riverine chironomids Extrmely high biomass turnover rates of

primary consumers Ecology 79899-910 Einarsson Aacute A Gardarsson GM Giacuteslason amp AR Ives 2002 Consumer-resource interactions and

cyclic population dynamics of Tanytarsus gracilentus (Diptera Chironomidae) Journal of Animal

Ecology 71832-845 Einarsson Aacute A Gardarsson GM Giacuteslason and G Gudbergsson 2006 Populations of ducks and trout

of the River Laxaacute Iceland in relation to variation in food resources Hydrobiologia 567183-194

Gardarsson A and Aacute Einarsson (in press) Density and production of Harlequin Ducks on the River

Laxaacute at Myacutevatn Iceland Waterbirds Gardarsson A JS Oacutelafsson Th Hrafnsdoacutettir G M Giacuteslason and Aacute Einarsson 1995 Monitoring

chironomid numbers at Myacutevatn Iceland the first sixteen years Pp 141-154 In P Cranston (ed)

Chironomids from genes to ecosystems CSIRO Publications Melbourne Gardarsson A Aacute Einarsson GM Giacuteslason Th Hrafnsdoacutettir HR Ingvason E Joacutensson amp JS

Oacutelafsson 2004 Population fluctuations of chironomid and simuliid Diptera at Myvatn in 1977-

1996 Aquatic Ecology 38209-217 Giacuteslason G M 1985 The life cycle and production of Simulium vittatum Zett in the River Laxaacute North-

East Iceland Verhandlungen Internationale Vereinigung fuumlr theoretische und angewandte

Limnologie 223281-3287

Giacuteslason G M 1994 River management in cold regions a case study of the River Laxaacute north Iceland In Calow P amp G E Petts (eds) The Rivers Handbook Vol 2 Blackwell Oxford464ndash483

Giacuteslason G M amp A Gardarsson 1988 Long term studies on Simulium vittatum Zett (Diptera

Simuliidae) in the River Laxaacute North Iceland with particular reference to different methods used in assessing population changes Verhandlungen Internationale Vereinigung fuumlr theoretische und

angewandte Limnologie 232179ndash2188

Giacuteslason G M amp V Joacutehannsson 1991 Effects of food and temperature on the life cycle of Simulium vittatum Zett (Diptera Simuliidae) in the River Laxaacute N-Iceland Verhandlungen Internationale

Vereinigung fuumlr theoretische und angewandte Limnologie 242912ndash2916

54

Giacuteslason GM amp Steingriacutemsson SOacute 2004 Seasonal and spatial variation in the diet of brown trout

(Salmo trutta L) in the subarctic River Laxaacute North-East Iceland Aquatic Ecology 38263-270 GiacuteslasonGM Th Hrafnsdoacutettir amp A Gardarsson 1995a Long term monitoring of numbers of

Chironomidae and Simuliidae in the River Laxaacute North Iceland Verhandlungen der Internationale

Vereinigung fuumlr Theoretische und Angewandte Limnologie 251492-1495

Giacuteslason G M Th Hrafnsdoacutettir amp A Gardarsson 1995b Flight periods of midges (Chironomidae and Simuliidae) in the River Laxa N-Iceland In P Cranston (ed) Chironomids Genes to Ecosystems

CSIRO Melbourne127ndash134

Giacuteslason GM J S Oacutelafsson amp H Adalsteinsson 1998 Animal communities in Icelandic rivers in relation to catchment characteristics and water chemistry preliminary results Nordic Hydrology

29129-148

Giacuteslason G M S Oacute Steingriacutemsson and G Gudbergsson 2002 Stock size and movements of landlocked brown trout (Salmo trutta L) in the subarctic River Laxaacute North-East Iceland Verhandlungen

Internationale Vereinigung fuumlr theoretische und angewandte Limnologie 281567-1571

Grzybkowska M 1989 Selective predation by Hydra sp on the larvae of Chironomidae Przeglad

Zoologiczny Wroclaw 32605-610 Hamilton A L 1969 On estimating annual production Limnology and Oceanography 14 771-782

Hynes HBN and MJ Coleman 1968 A simple method of assessing the annual production of stream

benthos Limnology and Oceanography 13569-573 Joacutensson E A Gardarsson and GM Giacuteslason 1986 A new window trap used in the assessment of the

flight periods of Chironomidae and Simuliidae (Diptera) Freshwater Biology 16711-719

Lindegaard C and E Mortensen 1988 Abundance life history and production of Chironomidae (Diptera) in a Danish lowland stream Archiv fuumlr Hydrobiologie 81563-587

Oacutelafsson J 1979a Physical characteristics of Lake Myacutevatn and River Laxaacute Oikos 3238-66

Oacutelafsson J 1979b The chemistry of Lake Myacutevatn and River Laxaacute Oikos 3282-112

Petersen Jr RC GM Giacuteslason og L B-M Vought 1995 Rivers of the Nordic Countries Pp 295-341 In CE Cushing KW Cummins and GW Minshall (eds) Ecosystems of the World Vol 22

River and Stream Ecosystems Elsevier Press Amsterdam

Rist S 1979 The hydrology of River Laxaacute Oikos 32271-280 Steingriacutemsson SOacute and GM Giacuteslason 2002 Body size diet and growth of landlocked brown trout

Salmo trutta in the subarctic river Laxaacute North-East Iceland Environmental Biology of Fishes

63417-426

Thoacuterarinsson S 1979 The postglacial history of the Myacutevatn area Oikos 3917-28 Wright AB and LA Smock 2001 Macroinvertebrate community structure and production in a low-

gradient stream in an undisturbed watershed Archiv fuumlr Hydrobiologie 152297-313

COVER PAGE of the XV International Symposium on Chironomidae

INSIDE TITLE AND CREDITS PAGE of the XV International Symposium on Chironomidae

Preface to The XV International Symposium on Chironomidae

NEW TABLE OF CONTENTS

Gislason and Gardarsson edited and formattedpdf


on Chironomidae

Edited by



ii









Copyright




Literature Citation

Text



Article




Credits






iii

iv





v








vi


ON CHIRONOMIDAE

Table of Contents



vii



viii

TAXONOMY














y-1


-2y

-1 at the


m-2


-2y

-1





INTRODUCTION















46





-1 and 1 m

3s














(1994)

METHODS







Gardarsson 1988)











2length


47



















1979a)


TAXON SAMPLE SITES


Chironomidae



Simuliidae



Total 100 100 100

RESULTS




were 136000 m-2





48


y-1


AFDW m-2

y-1


-2y


-2y

-1 at










Study Year 78-79 79-80 80-81 81-82 82-83 83-84 84-85

Chironomidae


B 46 38 11 --- --- --- 43

PB 58 62 66 --- --- --- 80

Helluvad (5 km) P 102 93 175 --- --- --- 127

B 22 25 24 --- --- --- 27

PB 47 37 72 --- --- --- 48

Thvera (24 km) P 97 173 --- --- --- --- ---

B 29 30 --- --- --- --- ---

PB 34 58 --- --- --- --- ---

Simulium vittatum


B 152 98 193 109 202 231 666

PB 35 28 52 53 27 22 90

Helluvad (5 km) P 211 125 132 212 212 189 796

B 45 32 25 42 136 65 220

PB 47 39 53 50 16 29 36

Thvera (24 km) P 247 239 251 467 692 668 897

B 42 66 34 127 132 120 140

PB 59 36 75 37 53 56 64





Gardarsson 1988)

49

DISCUSSION


y-1 a production



y-1


y-1

) Annual


y-1

(Lindegaard and




y-1


-2y


Midkvisl (outlet)

Density (

nos m

-2)

0

50000

100000

150000

200000

250000

300000


S vittatum

Thvera (24 km)

1978 1979 1980 1981 1982 1983 1984 1985

Density (

nos m

-2)

0

50000

100000

150000

200000

250000

300000

1200000

Helluvad (5 km)

Density (

nos m

-2)

0

50000

100000

150000

200000

250000

300000

1200000


50




Midkvisl (outlet)

Bio

ma

ss (

g a

fdw

m-2

)

0

10

20

3060

80Chironomidae

S vittatum

Thvera (24 km)

78-79 79-80 80-81 81-82 82-83 83-84 84-85

Bio

ma

ss (

g a

fdw

m-2

)

0

10

20

3060

80

Helluvad (5 km)

Bio

ma

ss (

g a

fdw

m-2

)

0

10

20

3060

80






51





Midkvisl (outlet)P

rod

uctio

n (

g a

fdw

m-2

yr-1

)

0

25

50

75

100

600 Chironomidae

S vittatum

Thvera (24 km)

78-79 79-80 80-81 81-82 82-83 83-84 84-85

Pro

du

ctio

n (

g a

fdw

m-2

yr-1

)

0

25

50

75

100

600

Helluvad (5 km)

Pro

du

ctio

n (

g a

fdw

m-2

yr-1

)

0

25

50

75

100

600




52








Chironomidae

Num

ber

0

50000

100000

150000

Dragsey(outlet)

Helluvad (5km)

S vittatum

19

76

19

78

19

80

19

82

19

84

19

86

19

88

19

90

19

92

19

94

19

96

19

98

20

00

20

02

20

04

Num

ber

0

100000

200000

300000

400000

Dragsey (outlet)

Helluvad (5 km)






53







ACKNOWLEDGMENTS





REFERENCES























54








29129-148















63417-426








ii









Copyright




Literature Citation

Text



Article




Credits






iii

iv





v








vi


ON CHIRONOMIDAE

Table of Contents



vii



viii

TAXONOMY














y-1


-2y

-1 at the


m-2


-2y

-1





INTRODUCTION















46





-1 and 1 m

3s














(1994)

METHODS







Gardarsson 1988)











2length


47



















1979a)


TAXON SAMPLE SITES


Chironomidae



Simuliidae



Total 100 100 100

RESULTS




were 136000 m-2





48


y-1


AFDW m-2

y-1


-2y


-2y

-1 at










Study Year 78-79 79-80 80-81 81-82 82-83 83-84 84-85

Chironomidae


B 46 38 11 --- --- --- 43

PB 58 62 66 --- --- --- 80

Helluvad (5 km) P 102 93 175 --- --- --- 127

B 22 25 24 --- --- --- 27

PB 47 37 72 --- --- --- 48

Thvera (24 km) P 97 173 --- --- --- --- ---

B 29 30 --- --- --- --- ---

PB 34 58 --- --- --- --- ---

Simulium vittatum


B 152 98 193 109 202 231 666

PB 35 28 52 53 27 22 90

Helluvad (5 km) P 211 125 132 212 212 189 796

B 45 32 25 42 136 65 220

PB 47 39 53 50 16 29 36

Thvera (24 km) P 247 239 251 467 692 668 897

B 42 66 34 127 132 120 140

PB 59 36 75 37 53 56 64





Gardarsson 1988)

49

DISCUSSION


y-1 a production



y-1


y-1

) Annual


y-1

(Lindegaard and




y-1


-2y


Midkvisl (outlet)

Density (

nos m

-2)

0

50000

100000

150000

200000

250000

300000


S vittatum

Thvera (24 km)

1978 1979 1980 1981 1982 1983 1984 1985

Density (

nos m

-2)

0

50000

100000

150000

200000

250000

300000

1200000

Helluvad (5 km)

Density (

nos m

-2)

0

50000

100000

150000

200000

250000

300000

1200000


50




Midkvisl (outlet)

Bio

ma

ss (

g a

fdw

m-2

)

0

10

20

3060

80Chironomidae

S vittatum

Thvera (24 km)

78-79 79-80 80-81 81-82 82-83 83-84 84-85

Bio

ma

ss (

g a

fdw

m-2

)

0

10

20

3060

80

Helluvad (5 km)

Bio

ma

ss (

g a

fdw

m-2

)

0

10

20

3060

80






51





Midkvisl (outlet)P

rod

uctio

n (

g a

fdw

m-2

yr-1

)

0

25

50

75

100

600 Chironomidae

S vittatum

Thvera (24 km)

78-79 79-80 80-81 81-82 82-83 83-84 84-85

Pro

du

ctio

n (

g a

fdw

m-2

yr-1

)

0

25

50

75

100

600

Helluvad (5 km)

Pro

du

ctio

n (

g a

fdw

m-2

yr-1

)

0

25

50

75

100

600




52








Chironomidae

Num

ber

0

50000

100000

150000

Dragsey(outlet)

Helluvad (5km)

S vittatum

19

76

19

78

19

80

19

82

19

84

19

86

19

88

19

90

19

92

19

94

19

96

19

98

20

00

20

02

20

04

Num

ber

0

100000

200000

300000

400000

Dragsey (outlet)

Helluvad (5 km)






53







ACKNOWLEDGMENTS





REFERENCES























54








29129-148















63417-426








iii

iv





v








vi


ON CHIRONOMIDAE

Table of Contents



vii



viii

TAXONOMY














y-1


-2y

-1 at the


m-2


-2y

-1





INTRODUCTION















46





-1 and 1 m

3s














(1994)

METHODS







Gardarsson 1988)











2length


47



















1979a)


TAXON SAMPLE SITES


Chironomidae



Simuliidae



Total 100 100 100

RESULTS




were 136000 m-2





48


y-1


AFDW m-2

y-1


-2y


-2y

-1 at










Study Year 78-79 79-80 80-81 81-82 82-83 83-84 84-85

Chironomidae


B 46 38 11 --- --- --- 43

PB 58 62 66 --- --- --- 80

Helluvad (5 km) P 102 93 175 --- --- --- 127

B 22 25 24 --- --- --- 27

PB 47 37 72 --- --- --- 48

Thvera (24 km) P 97 173 --- --- --- --- ---

B 29 30 --- --- --- --- ---

PB 34 58 --- --- --- --- ---

Simulium vittatum


B 152 98 193 109 202 231 666

PB 35 28 52 53 27 22 90

Helluvad (5 km) P 211 125 132 212 212 189 796

B 45 32 25 42 136 65 220

PB 47 39 53 50 16 29 36

Thvera (24 km) P 247 239 251 467 692 668 897

B 42 66 34 127 132 120 140

PB 59 36 75 37 53 56 64





Gardarsson 1988)

49

DISCUSSION


y-1 a production



y-1


y-1

) Annual


y-1

(Lindegaard and




y-1


-2y


Midkvisl (outlet)

Density (

nos m

-2)

0

50000

100000

150000

200000

250000

300000


S vittatum

Thvera (24 km)

1978 1979 1980 1981 1982 1983 1984 1985

Density (

nos m

-2)

0

50000

100000

150000

200000

250000

300000

1200000

Helluvad (5 km)

Density (

nos m

-2)

0

50000

100000

150000

200000

250000

300000

1200000


50




Midkvisl (outlet)

Bio

ma

ss (

g a

fdw

m-2

)

0

10

20

3060

80Chironomidae

S vittatum

Thvera (24 km)

78-79 79-80 80-81 81-82 82-83 83-84 84-85

Bio

ma

ss (

g a

fdw

m-2

)

0

10

20

3060

80

Helluvad (5 km)

Bio

ma

ss (

g a

fdw

m-2

)

0

10

20

3060

80






51





Midkvisl (outlet)P

rod

uctio

n (

g a

fdw

m-2

yr-1

)

0

25

50

75

100

600 Chironomidae

S vittatum

Thvera (24 km)

78-79 79-80 80-81 81-82 82-83 83-84 84-85

Pro

du

ctio

n (

g a

fdw

m-2

yr-1

)

0

25

50

75

100

600

Helluvad (5 km)

Pro

du

ctio

n (

g a

fdw

m-2

yr-1

)

0

25

50

75

100

600




52








Chironomidae

Num

ber

0

50000

100000

150000

Dragsey(outlet)

Helluvad (5km)

S vittatum

19

76

19

78

19

80

19

82

19

84

19

86

19

88

19

90

19

92

19

94

19

96

19

98

20

00

20

02

20

04

Num

ber

0

100000

200000

300000

400000

Dragsey (outlet)

Helluvad (5 km)






53







ACKNOWLEDGMENTS





REFERENCES























54








29129-148















63417-426








iv





v








vi


ON CHIRONOMIDAE

Table of Contents



vii



viii

TAXONOMY














y-1


-2y

-1 at the


m-2


-2y

-1





INTRODUCTION















46





-1 and 1 m

3s














(1994)

METHODS







Gardarsson 1988)











2length


47



















1979a)


TAXON SAMPLE SITES


Chironomidae



Simuliidae



Total 100 100 100

RESULTS




were 136000 m-2





48


y-1


AFDW m-2

y-1


-2y


-2y

-1 at










Study Year 78-79 79-80 80-81 81-82 82-83 83-84 84-85

Chironomidae


B 46 38 11 --- --- --- 43

PB 58 62 66 --- --- --- 80

Helluvad (5 km) P 102 93 175 --- --- --- 127

B 22 25 24 --- --- --- 27

PB 47 37 72 --- --- --- 48

Thvera (24 km) P 97 173 --- --- --- --- ---

B 29 30 --- --- --- --- ---

PB 34 58 --- --- --- --- ---

Simulium vittatum


B 152 98 193 109 202 231 666

PB 35 28 52 53 27 22 90

Helluvad (5 km) P 211 125 132 212 212 189 796

B 45 32 25 42 136 65 220

PB 47 39 53 50 16 29 36

Thvera (24 km) P 247 239 251 467 692 668 897

B 42 66 34 127 132 120 140

PB 59 36 75 37 53 56 64





Gardarsson 1988)

49

DISCUSSION


y-1 a production



y-1


y-1

) Annual


y-1

(Lindegaard and




y-1


-2y


Midkvisl (outlet)

Density (

nos m

-2)

0

50000

100000

150000

200000

250000

300000


S vittatum

Thvera (24 km)

1978 1979 1980 1981 1982 1983 1984 1985

Density (

nos m

-2)

0

50000

100000

150000

200000

250000

300000

1200000

Helluvad (5 km)

Density (

nos m

-2)

0

50000

100000

150000

200000

250000

300000

1200000


50




Midkvisl (outlet)

Bio

ma

ss (

g a

fdw

m-2

)

0

10

20

3060

80Chironomidae

S vittatum

Thvera (24 km)

78-79 79-80 80-81 81-82 82-83 83-84 84-85

Bio

ma

ss (

g a

fdw

m-2

)

0

10

20

3060

80

Helluvad (5 km)

Bio

ma

ss (

g a

fdw

m-2

)

0

10

20

3060

80






51





Midkvisl (outlet)P

rod

uctio

n (

g a

fdw

m-2

yr-1

)

0

25

50

75

100

600 Chironomidae

S vittatum

Thvera (24 km)

78-79 79-80 80-81 81-82 82-83 83-84 84-85

Pro

du

ctio

n (

g a

fdw

m-2

yr-1

)

0

25

50

75

100

600

Helluvad (5 km)

Pro

du

ctio

n (

g a

fdw

m-2

yr-1

)

0

25

50

75

100

600




52








Chironomidae

Num

ber

0

50000

100000

150000

Dragsey(outlet)

Helluvad (5km)

S vittatum

19

76

19

78

19

80

19

82

19

84

19

86

19

88

19

90

19

92

19

94

19

96

19

98

20

00

20

02

20

04

Num

ber

0

100000

200000

300000

400000

Dragsey (outlet)

Helluvad (5 km)






53







ACKNOWLEDGMENTS





REFERENCES























54








29129-148















63417-426








v








vi


ON CHIRONOMIDAE

Table of Contents



vii



viii

TAXONOMY














y-1


-2y

-1 at the


m-2


-2y

-1





INTRODUCTION















46





-1 and 1 m

3s














(1994)

METHODS







Gardarsson 1988)











2length


47



















1979a)


TAXON SAMPLE SITES


Chironomidae



Simuliidae



Total 100 100 100

RESULTS




were 136000 m-2





48


y-1


AFDW m-2

y-1


-2y


-2y

-1 at










Study Year 78-79 79-80 80-81 81-82 82-83 83-84 84-85

Chironomidae


B 46 38 11 --- --- --- 43

PB 58 62 66 --- --- --- 80

Helluvad (5 km) P 102 93 175 --- --- --- 127

B 22 25 24 --- --- --- 27

PB 47 37 72 --- --- --- 48

Thvera (24 km) P 97 173 --- --- --- --- ---

B 29 30 --- --- --- --- ---

PB 34 58 --- --- --- --- ---

Simulium vittatum


B 152 98 193 109 202 231 666

PB 35 28 52 53 27 22 90

Helluvad (5 km) P 211 125 132 212 212 189 796

B 45 32 25 42 136 65 220

PB 47 39 53 50 16 29 36

Thvera (24 km) P 247 239 251 467 692 668 897

B 42 66 34 127 132 120 140

PB 59 36 75 37 53 56 64





Gardarsson 1988)

49

DISCUSSION


y-1 a production



y-1


y-1

) Annual


y-1

(Lindegaard and




y-1


-2y


Midkvisl (outlet)

Density (

nos m

-2)

0

50000

100000

150000

200000

250000

300000


S vittatum

Thvera (24 km)

1978 1979 1980 1981 1982 1983 1984 1985

Density (

nos m

-2)

0

50000

100000

150000

200000

250000

300000

1200000

Helluvad (5 km)

Density (

nos m

-2)

0

50000

100000

150000

200000

250000

300000

1200000


50




Midkvisl (outlet)

Bio

ma

ss (

g a

fdw

m-2

)

0

10

20

3060

80Chironomidae

S vittatum

Thvera (24 km)

78-79 79-80 80-81 81-82 82-83 83-84 84-85

Bio

ma

ss (

g a

fdw

m-2

)

0

10

20

3060

80

Helluvad (5 km)

Bio

ma

ss (

g a

fdw

m-2

)

0

10

20

3060

80






51





Midkvisl (outlet)P

rod

uctio

n (

g a

fdw

m-2

yr-1

)

0

25

50

75

100

600 Chironomidae

S vittatum

Thvera (24 km)

78-79 79-80 80-81 81-82 82-83 83-84 84-85

Pro

du

ctio

n (

g a

fdw

m-2

yr-1

)

0

25

50

75

100

600

Helluvad (5 km)

Pro

du

ctio

n (

g a

fdw

m-2

yr-1

)

0

25

50

75

100

600




52








Chironomidae

Num

ber

0

50000

100000

150000

Dragsey(outlet)

Helluvad (5km)

S vittatum

19

76

19

78

19

80

19

82

19

84

19

86

19

88

19

90

19

92

19

94

19

96

19

98

20

00

20

02

20

04

Num

ber

0

100000

200000

300000

400000

Dragsey (outlet)

Helluvad (5 km)






53







ACKNOWLEDGMENTS





REFERENCES























54








29129-148















63417-426








vi


ON CHIRONOMIDAE

Table of Contents



vii



viii

TAXONOMY














y-1


-2y

-1 at the


m-2


-2y

-1





INTRODUCTION















46





-1 and 1 m

3s














(1994)

METHODS







Gardarsson 1988)











2length


47



















1979a)


TAXON SAMPLE SITES


Chironomidae



Simuliidae



Total 100 100 100

RESULTS




were 136000 m-2





48


y-1


AFDW m-2

y-1


-2y


-2y

-1 at










Study Year 78-79 79-80 80-81 81-82 82-83 83-84 84-85

Chironomidae


B 46 38 11 --- --- --- 43

PB 58 62 66 --- --- --- 80

Helluvad (5 km) P 102 93 175 --- --- --- 127

B 22 25 24 --- --- --- 27

PB 47 37 72 --- --- --- 48

Thvera (24 km) P 97 173 --- --- --- --- ---

B 29 30 --- --- --- --- ---

PB 34 58 --- --- --- --- ---

Simulium vittatum


B 152 98 193 109 202 231 666

PB 35 28 52 53 27 22 90

Helluvad (5 km) P 211 125 132 212 212 189 796

B 45 32 25 42 136 65 220

PB 47 39 53 50 16 29 36

Thvera (24 km) P 247 239 251 467 692 668 897

B 42 66 34 127 132 120 140

PB 59 36 75 37 53 56 64





Gardarsson 1988)

49

DISCUSSION


y-1 a production



y-1


y-1

) Annual


y-1

(Lindegaard and




y-1


-2y


Midkvisl (outlet)

Density (

nos m

-2)

0

50000

100000

150000

200000

250000

300000


S vittatum

Thvera (24 km)

1978 1979 1980 1981 1982 1983 1984 1985

Density (

nos m

-2)

0

50000

100000

150000

200000

250000

300000

1200000

Helluvad (5 km)

Density (

nos m

-2)

0

50000

100000

150000

200000

250000

300000

1200000


50




Midkvisl (outlet)

Bio

ma

ss (

g a

fdw

m-2

)

0

10

20

3060

80Chironomidae

S vittatum

Thvera (24 km)

78-79 79-80 80-81 81-82 82-83 83-84 84-85

Bio

ma

ss (

g a

fdw

m-2

)

0

10

20

3060

80

Helluvad (5 km)

Bio

ma

ss (

g a

fdw

m-2

)

0

10

20

3060

80






51





Midkvisl (outlet)P

rod

uctio

n (

g a

fdw

m-2

yr-1

)

0

25

50

75

100

600 Chironomidae

S vittatum

Thvera (24 km)

78-79 79-80 80-81 81-82 82-83 83-84 84-85

Pro

du

ctio

n (

g a

fdw

m-2

yr-1

)

0

25

50

75

100

600

Helluvad (5 km)

Pro

du

ctio

n (

g a

fdw

m-2

yr-1

)

0

25

50

75

100

600




52








Chironomidae

Num

ber

0

50000

100000

150000

Dragsey(outlet)

Helluvad (5km)

S vittatum

19

76

19

78

19

80

19

82

19

84

19

86

19

88

19

90

19

92

19

94

19

96

19

98

20

00

20

02

20

04

Num

ber

0

100000

200000

300000

400000

Dragsey (outlet)

Helluvad (5 km)






53







ACKNOWLEDGMENTS





REFERENCES























54








29129-148















63417-426








vii



viii

TAXONOMY














y-1


-2y

-1 at the


m-2


-2y

-1





INTRODUCTION















46





-1 and 1 m

3s














(1994)

METHODS







Gardarsson 1988)











2length


47



















1979a)


TAXON SAMPLE SITES


Chironomidae



Simuliidae



Total 100 100 100

RESULTS




were 136000 m-2





48


y-1


AFDW m-2

y-1


-2y


-2y

-1 at










Study Year 78-79 79-80 80-81 81-82 82-83 83-84 84-85

Chironomidae


B 46 38 11 --- --- --- 43

PB 58 62 66 --- --- --- 80

Helluvad (5 km) P 102 93 175 --- --- --- 127

B 22 25 24 --- --- --- 27

PB 47 37 72 --- --- --- 48

Thvera (24 km) P 97 173 --- --- --- --- ---

B 29 30 --- --- --- --- ---

PB 34 58 --- --- --- --- ---

Simulium vittatum


B 152 98 193 109 202 231 666

PB 35 28 52 53 27 22 90

Helluvad (5 km) P 211 125 132 212 212 189 796

B 45 32 25 42 136 65 220

PB 47 39 53 50 16 29 36

Thvera (24 km) P 247 239 251 467 692 668 897

B 42 66 34 127 132 120 140

PB 59 36 75 37 53 56 64





Gardarsson 1988)

49

DISCUSSION


y-1 a production



y-1


y-1

) Annual


y-1

(Lindegaard and




y-1


-2y


Midkvisl (outlet)

Density (

nos m

-2)

0

50000

100000

150000

200000

250000

300000


S vittatum

Thvera (24 km)

1978 1979 1980 1981 1982 1983 1984 1985

Density (

nos m

-2)

0

50000

100000

150000

200000

250000

300000

1200000

Helluvad (5 km)

Density (

nos m

-2)

0

50000

100000

150000

200000

250000

300000

1200000


50




Midkvisl (outlet)

Bio

ma

ss (

g a

fdw

m-2

)

0

10

20

3060

80Chironomidae

S vittatum

Thvera (24 km)

78-79 79-80 80-81 81-82 82-83 83-84 84-85

Bio

ma

ss (

g a

fdw

m-2

)

0

10

20

3060

80

Helluvad (5 km)

Bio

ma

ss (

g a

fdw

m-2

)

0

10

20

3060

80






51





Midkvisl (outlet)P

rod

uctio

n (

g a

fdw

m-2

yr-1

)

0

25

50

75

100

600 Chironomidae

S vittatum

Thvera (24 km)

78-79 79-80 80-81 81-82 82-83 83-84 84-85

Pro

du

ctio

n (

g a

fdw

m-2

yr-1

)

0

25

50

75

100

600

Helluvad (5 km)

Pro

du

ctio

n (

g a

fdw

m-2

yr-1

)

0

25

50

75

100

600




52








Chironomidae

Num

ber

0

50000

100000

150000

Dragsey(outlet)

Helluvad (5km)

S vittatum

19

76

19

78

19

80

19

82

19

84

19

86

19

88

19

90

19

92

19

94

19

96

19

98

20

00

20

02

20

04

Num

ber

0

100000

200000

300000

400000

Dragsey (outlet)

Helluvad (5 km)






53







ACKNOWLEDGMENTS





REFERENCES























54








29129-148















63417-426








viii

TAXONOMY














y-1


-2y

-1 at the


m-2


-2y

-1





INTRODUCTION















46





-1 and 1 m

3s














(1994)

METHODS







Gardarsson 1988)











2length


47



















1979a)


TAXON SAMPLE SITES


Chironomidae



Simuliidae



Total 100 100 100

RESULTS




were 136000 m-2





48


y-1


AFDW m-2

y-1


-2y


-2y

-1 at










Study Year 78-79 79-80 80-81 81-82 82-83 83-84 84-85

Chironomidae


B 46 38 11 --- --- --- 43

PB 58 62 66 --- --- --- 80

Helluvad (5 km) P 102 93 175 --- --- --- 127

B 22 25 24 --- --- --- 27

PB 47 37 72 --- --- --- 48

Thvera (24 km) P 97 173 --- --- --- --- ---

B 29 30 --- --- --- --- ---

PB 34 58 --- --- --- --- ---

Simulium vittatum


B 152 98 193 109 202 231 666

PB 35 28 52 53 27 22 90

Helluvad (5 km) P 211 125 132 212 212 189 796

B 45 32 25 42 136 65 220

PB 47 39 53 50 16 29 36

Thvera (24 km) P 247 239 251 467 692 668 897

B 42 66 34 127 132 120 140

PB 59 36 75 37 53 56 64





Gardarsson 1988)

49

DISCUSSION


y-1 a production



y-1


y-1

) Annual


y-1

(Lindegaard and




y-1


-2y


Midkvisl (outlet)

Density (

nos m

-2)

0

50000

100000

150000

200000

250000

300000


S vittatum

Thvera (24 km)

1978 1979 1980 1981 1982 1983 1984 1985

Density (

nos m

-2)

0

50000

100000

150000

200000

250000

300000

1200000

Helluvad (5 km)

Density (

nos m

-2)

0

50000

100000

150000

200000

250000

300000

1200000


50




Midkvisl (outlet)

Bio

ma

ss (

g a

fdw

m-2

)

0

10

20

3060

80Chironomidae

S vittatum

Thvera (24 km)

78-79 79-80 80-81 81-82 82-83 83-84 84-85

Bio

ma

ss (

g a

fdw

m-2

)

0

10

20

3060

80

Helluvad (5 km)

Bio

ma

ss (

g a

fdw

m-2

)

0

10

20

3060

80






51





Midkvisl (outlet)P

rod

uctio

n (

g a

fdw

m-2

yr-1

)

0

25

50

75

100

600 Chironomidae

S vittatum

Thvera (24 km)

78-79 79-80 80-81 81-82 82-83 83-84 84-85

Pro

du

ctio

n (

g a

fdw

m-2

yr-1

)

0

25

50

75

100

600

Helluvad (5 km)

Pro

du

ctio

n (

g a

fdw

m-2

yr-1

)

0

25

50

75

100

600




52








Chironomidae

Num

ber

0

50000

100000

150000

Dragsey(outlet)

Helluvad (5km)

S vittatum

19

76

19

78

19

80

19

82

19

84

19

86

19

88

19

90

19

92

19

94

19

96

19

98

20

00

20

02

20

04

Num

ber

0

100000

200000

300000

400000

Dragsey (outlet)

Helluvad (5 km)






53







ACKNOWLEDGMENTS





REFERENCES























54








29129-148















63417-426


















y-1


-2y

-1 at the


m-2


-2y

-1





INTRODUCTION















46





-1 and 1 m

3s














(1994)

METHODS







Gardarsson 1988)











2length


47



















1979a)


TAXON SAMPLE SITES


Chironomidae



Simuliidae



Total 100 100 100

RESULTS




were 136000 m-2





48


y-1


AFDW m-2

y-1


-2y


-2y

-1 at










Study Year 78-79 79-80 80-81 81-82 82-83 83-84 84-85

Chironomidae


B 46 38 11 --- --- --- 43

PB 58 62 66 --- --- --- 80

Helluvad (5 km) P 102 93 175 --- --- --- 127

B 22 25 24 --- --- --- 27

PB 47 37 72 --- --- --- 48

Thvera (24 km) P 97 173 --- --- --- --- ---

B 29 30 --- --- --- --- ---

PB 34 58 --- --- --- --- ---

Simulium vittatum


B 152 98 193 109 202 231 666

PB 35 28 52 53 27 22 90

Helluvad (5 km) P 211 125 132 212 212 189 796

B 45 32 25 42 136 65 220

PB 47 39 53 50 16 29 36

Thvera (24 km) P 247 239 251 467 692 668 897

B 42 66 34 127 132 120 140

PB 59 36 75 37 53 56 64





Gardarsson 1988)

49

DISCUSSION


y-1 a production



y-1


y-1

) Annual


y-1

(Lindegaard and




y-1


-2y


Midkvisl (outlet)

Density (

nos m

-2)

0

50000

100000

150000

200000

250000

300000


S vittatum

Thvera (24 km)

1978 1979 1980 1981 1982 1983 1984 1985

Density (

nos m

-2)

0

50000

100000

150000

200000

250000

300000

1200000

Helluvad (5 km)

Density (

nos m

-2)

0

50000

100000

150000

200000

250000

300000

1200000


50




Midkvisl (outlet)

Bio

ma

ss (

g a

fdw

m-2

)

0

10

20

3060

80Chironomidae

S vittatum

Thvera (24 km)

78-79 79-80 80-81 81-82 82-83 83-84 84-85

Bio

ma

ss (

g a

fdw

m-2

)

0

10

20

3060

80

Helluvad (5 km)

Bio

ma

ss (

g a

fdw

m-2

)

0

10

20

3060

80






51





Midkvisl (outlet)P

rod

uctio

n (

g a

fdw

m-2

yr-1

)

0

25

50

75

100

600 Chironomidae

S vittatum

Thvera (24 km)

78-79 79-80 80-81 81-82 82-83 83-84 84-85

Pro

du

ctio

n (

g a

fdw

m-2

yr-1

)

0

25

50

75

100

600

Helluvad (5 km)

Pro

du

ctio

n (

g a

fdw

m-2

yr-1

)

0

25

50

75

100

600




52








Chironomidae

Num

ber

0

50000

100000

150000

Dragsey(outlet)

Helluvad (5km)

S vittatum

19

76

19

78

19

80

19

82

19

84

19

86

19

88

19

90

19

92

19

94

19

96

19

98

20

00

20

02

20

04

Num

ber

0

100000

200000

300000

400000

Dragsey (outlet)

Helluvad (5 km)






53







ACKNOWLEDGMENTS





REFERENCES























54








29129-148















63417-426








46





-1 and 1 m

3s














(1994)

METHODS







Gardarsson 1988)











2length


47



















1979a)


TAXON SAMPLE SITES


Chironomidae



Simuliidae



Total 100 100 100

RESULTS




were 136000 m-2





48


y-1


AFDW m-2

y-1


-2y


-2y

-1 at










Study Year 78-79 79-80 80-81 81-82 82-83 83-84 84-85

Chironomidae


B 46 38 11 --- --- --- 43

PB 58 62 66 --- --- --- 80

Helluvad (5 km) P 102 93 175 --- --- --- 127

B 22 25 24 --- --- --- 27

PB 47 37 72 --- --- --- 48

Thvera (24 km) P 97 173 --- --- --- --- ---

B 29 30 --- --- --- --- ---

PB 34 58 --- --- --- --- ---

Simulium vittatum


B 152 98 193 109 202 231 666

PB 35 28 52 53 27 22 90

Helluvad (5 km) P 211 125 132 212 212 189 796

B 45 32 25 42 136 65 220

PB 47 39 53 50 16 29 36

Thvera (24 km) P 247 239 251 467 692 668 897

B 42 66 34 127 132 120 140

PB 59 36 75 37 53 56 64





Gardarsson 1988)

49

DISCUSSION


y-1 a production



y-1


y-1

) Annual


y-1

(Lindegaard and




y-1


-2y


Midkvisl (outlet)

Density (

nos m

-2)

0

50000

100000

150000

200000

250000

300000


S vittatum

Thvera (24 km)

1978 1979 1980 1981 1982 1983 1984 1985

Density (

nos m

-2)

0

50000

100000

150000

200000

250000

300000

1200000

Helluvad (5 km)

Density (

nos m

-2)

0

50000

100000

150000

200000

250000

300000

1200000


50




Midkvisl (outlet)

Bio

ma

ss (

g a

fdw

m-2

)

0

10

20

3060

80Chironomidae

S vittatum

Thvera (24 km)

78-79 79-80 80-81 81-82 82-83 83-84 84-85

Bio

ma

ss (

g a

fdw

m-2

)

0

10

20

3060

80

Helluvad (5 km)

Bio

ma

ss (

g a

fdw

m-2

)

0

10

20

3060

80






51





Midkvisl (outlet)P

rod

uctio

n (

g a

fdw

m-2

yr-1

)

0

25

50

75

100

600 Chironomidae

S vittatum

Thvera (24 km)

78-79 79-80 80-81 81-82 82-83 83-84 84-85

Pro

du

ctio

n (

g a

fdw

m-2

yr-1

)

0

25

50

75

100

600

Helluvad (5 km)

Pro

du

ctio

n (

g a

fdw

m-2

yr-1

)

0

25

50

75

100

600




52








Chironomidae

Num

ber

0

50000

100000

150000

Dragsey(outlet)

Helluvad (5km)

S vittatum

19

76

19

78

19

80

19

82

19

84

19

86

19

88

19

90

19

92

19

94

19

96

19

98

20

00

20

02

20

04

Num

ber

0

100000

200000

300000

400000

Dragsey (outlet)

Helluvad (5 km)






53







ACKNOWLEDGMENTS





REFERENCES























54








29129-148















63417-426








47



















1979a)


TAXON SAMPLE SITES


Chironomidae



Simuliidae



Total 100 100 100

RESULTS




were 136000 m-2





48


y-1


AFDW m-2

y-1


-2y


-2y

-1 at










Study Year 78-79 79-80 80-81 81-82 82-83 83-84 84-85

Chironomidae


B 46 38 11 --- --- --- 43

PB 58 62 66 --- --- --- 80

Helluvad (5 km) P 102 93 175 --- --- --- 127

B 22 25 24 --- --- --- 27

PB 47 37 72 --- --- --- 48

Thvera (24 km) P 97 173 --- --- --- --- ---

B 29 30 --- --- --- --- ---

PB 34 58 --- --- --- --- ---

Simulium vittatum


B 152 98 193 109 202 231 666

PB 35 28 52 53 27 22 90

Helluvad (5 km) P 211 125 132 212 212 189 796

B 45 32 25 42 136 65 220

PB 47 39 53 50 16 29 36

Thvera (24 km) P 247 239 251 467 692 668 897

B 42 66 34 127 132 120 140

PB 59 36 75 37 53 56 64





Gardarsson 1988)

49

DISCUSSION


y-1 a production



y-1


y-1

) Annual


y-1

(Lindegaard and




y-1


-2y


Midkvisl (outlet)

Density (

nos m

-2)

0

50000

100000

150000

200000

250000

300000


S vittatum

Thvera (24 km)

1978 1979 1980 1981 1982 1983 1984 1985

Density (

nos m

-2)

0

50000

100000

150000

200000

250000

300000

1200000

Helluvad (5 km)

Density (

nos m

-2)

0

50000

100000

150000

200000

250000

300000

1200000


50




Midkvisl (outlet)

Bio

ma

ss (

g a

fdw

m-2

)

0

10

20

3060

80Chironomidae

S vittatum

Thvera (24 km)

78-79 79-80 80-81 81-82 82-83 83-84 84-85

Bio

ma

ss (

g a

fdw

m-2

)

0

10

20

3060

80

Helluvad (5 km)

Bio

ma

ss (

g a

fdw

m-2

)

0

10

20

3060

80






51





Midkvisl (outlet)P

rod

uctio

n (

g a

fdw

m-2

yr-1

)

0

25

50

75

100

600 Chironomidae

S vittatum

Thvera (24 km)

78-79 79-80 80-81 81-82 82-83 83-84 84-85

Pro

du

ctio

n (

g a

fdw

m-2

yr-1

)

0

25

50

75

100

600

Helluvad (5 km)

Pro

du

ctio

n (

g a

fdw

m-2

yr-1

)

0

25

50

75

100

600




52








Chironomidae

Num

ber

0

50000

100000

150000

Dragsey(outlet)

Helluvad (5km)

S vittatum

19

76

19

78

19

80

19

82

19

84

19

86

19

88

19

90

19

92

19

94

19

96

19

98

20

00

20

02

20

04

Num

ber

0

100000

200000

300000

400000

Dragsey (outlet)

Helluvad (5 km)






53







ACKNOWLEDGMENTS





REFERENCES























54








29129-148















63417-426








48


y-1


AFDW m-2

y-1


-2y


-2y

-1 at










Study Year 78-79 79-80 80-81 81-82 82-83 83-84 84-85

Chironomidae


B 46 38 11 --- --- --- 43

PB 58 62 66 --- --- --- 80

Helluvad (5 km) P 102 93 175 --- --- --- 127

B 22 25 24 --- --- --- 27

PB 47 37 72 --- --- --- 48

Thvera (24 km) P 97 173 --- --- --- --- ---

B 29 30 --- --- --- --- ---

PB 34 58 --- --- --- --- ---

Simulium vittatum


B 152 98 193 109 202 231 666

PB 35 28 52 53 27 22 90

Helluvad (5 km) P 211 125 132 212 212 189 796

B 45 32 25 42 136 65 220

PB 47 39 53 50 16 29 36

Thvera (24 km) P 247 239 251 467 692 668 897

B 42 66 34 127 132 120 140

PB 59 36 75 37 53 56 64





Gardarsson 1988)

49

DISCUSSION


y-1 a production



y-1


y-1

) Annual


y-1

(Lindegaard and




y-1


-2y


Midkvisl (outlet)

Density (

nos m

-2)

0

50000

100000

150000

200000

250000

300000


S vittatum

Thvera (24 km)

1978 1979 1980 1981 1982 1983 1984 1985

Density (

nos m

-2)

0

50000

100000

150000

200000

250000

300000

1200000

Helluvad (5 km)

Density (

nos m

-2)

0

50000

100000

150000

200000

250000

300000

1200000


50




Midkvisl (outlet)

Bio

ma

ss (

g a

fdw

m-2

)

0

10

20

3060

80Chironomidae

S vittatum

Thvera (24 km)

78-79 79-80 80-81 81-82 82-83 83-84 84-85

Bio

ma

ss (

g a

fdw

m-2

)

0

10

20

3060

80

Helluvad (5 km)

Bio

ma

ss (

g a

fdw

m-2

)

0

10

20

3060

80






51





Midkvisl (outlet)P

rod

uctio

n (

g a

fdw

m-2

yr-1

)

0

25

50

75

100

600 Chironomidae

S vittatum

Thvera (24 km)

78-79 79-80 80-81 81-82 82-83 83-84 84-85

Pro

du

ctio

n (

g a

fdw

m-2

yr-1

)

0

25

50

75

100

600

Helluvad (5 km)

Pro

du

ctio

n (

g a

fdw

m-2

yr-1

)

0

25

50

75

100

600




52








Chironomidae

Num

ber

0

50000

100000

150000

Dragsey(outlet)

Helluvad (5km)

S vittatum

19

76

19

78

19

80

19

82

19

84

19

86

19

88

19

90

19

92

19

94

19

96

19

98

20

00

20

02

20

04

Num

ber

0

100000

200000

300000

400000

Dragsey (outlet)

Helluvad (5 km)






53







ACKNOWLEDGMENTS





REFERENCES























54








29129-148















63417-426








49

DISCUSSION


y-1 a production



y-1


y-1

) Annual


y-1

(Lindegaard and




y-1


-2y


Midkvisl (outlet)

Density (

nos m

-2)

0

50000

100000

150000

200000

250000

300000


S vittatum

Thvera (24 km)

1978 1979 1980 1981 1982 1983 1984 1985

Density (

nos m

-2)

0

50000

100000

150000

200000

250000

300000

1200000

Helluvad (5 km)

Density (

nos m

-2)

0

50000

100000

150000

200000

250000

300000

1200000


50




Midkvisl (outlet)

Bio

ma

ss (

g a

fdw

m-2

)

0

10

20

3060

80Chironomidae

S vittatum

Thvera (24 km)

78-79 79-80 80-81 81-82 82-83 83-84 84-85

Bio

ma

ss (

g a

fdw

m-2

)

0

10

20

3060

80

Helluvad (5 km)

Bio

ma

ss (

g a

fdw

m-2

)

0

10

20

3060

80






51





Midkvisl (outlet)P

rod

uctio

n (

g a

fdw

m-2

yr-1

)

0

25

50

75

100

600 Chironomidae

S vittatum

Thvera (24 km)

78-79 79-80 80-81 81-82 82-83 83-84 84-85

Pro

du

ctio

n (

g a

fdw

m-2

yr-1

)

0

25

50

75

100

600

Helluvad (5 km)

Pro

du

ctio

n (

g a

fdw

m-2

yr-1

)

0

25

50

75

100

600




52








Chironomidae

Num

ber

0

50000

100000

150000

Dragsey(outlet)

Helluvad (5km)

S vittatum

19

76

19

78

19

80

19

82

19

84

19

86

19

88

19

90

19

92

19

94

19

96

19

98

20

00

20

02

20

04

Num

ber

0

100000

200000

300000

400000

Dragsey (outlet)

Helluvad (5 km)






53







ACKNOWLEDGMENTS





REFERENCES























54








29129-148















63417-426








50




Midkvisl (outlet)

Bio

ma

ss (

g a

fdw

m-2

)

0

10

20

3060

80Chironomidae

S vittatum

Thvera (24 km)

78-79 79-80 80-81 81-82 82-83 83-84 84-85

Bio

ma

ss (

g a

fdw

m-2

)

0

10

20

3060

80

Helluvad (5 km)

Bio

ma

ss (

g a

fdw

m-2

)

0

10

20

3060

80






51





Midkvisl (outlet)P

rod

uctio

n (

g a

fdw

m-2

yr-1

)

0

25

50

75

100

600 Chironomidae

S vittatum

Thvera (24 km)

78-79 79-80 80-81 81-82 82-83 83-84 84-85

Pro

du

ctio

n (

g a

fdw

m-2

yr-1

)

0

25

50

75

100

600

Helluvad (5 km)

Pro

du

ctio

n (

g a

fdw

m-2

yr-1

)

0

25

50

75

100

600




52








Chironomidae

Num

ber

0

50000

100000

150000

Dragsey(outlet)

Helluvad (5km)

S vittatum

19

76

19

78

19

80

19

82

19

84

19

86

19

88

19

90

19

92

19

94

19

96

19

98

20

00

20

02

20

04

Num

ber

0

100000

200000

300000

400000

Dragsey (outlet)

Helluvad (5 km)






53







ACKNOWLEDGMENTS





REFERENCES























54








29129-148















63417-426








51





Midkvisl (outlet)P

rod

uctio

n (

g a

fdw

m-2

yr-1

)

0

25

50

75

100

600 Chironomidae

S vittatum

Thvera (24 km)

78-79 79-80 80-81 81-82 82-83 83-84 84-85

Pro

du

ctio

n (

g a

fdw

m-2

yr-1

)

0

25

50

75

100

600

Helluvad (5 km)

Pro

du

ctio

n (

g a

fdw

m-2

yr-1

)

0

25

50

75

100

600




52








Chironomidae

Num

ber

0

50000

100000

150000

Dragsey(outlet)

Helluvad (5km)

S vittatum

19

76

19

78

19

80

19

82

19

84

19

86

19

88

19

90

19

92

19

94

19

96

19

98

20

00

20

02

20

04

Num

ber

0

100000

200000

300000

400000

Dragsey (outlet)

Helluvad (5 km)






53







ACKNOWLEDGMENTS





REFERENCES























54








29129-148















63417-426








52








Chironomidae

Num

ber

0

50000

100000

150000

Dragsey(outlet)

Helluvad (5km)

S vittatum

19

76

19

78

19

80

19

82

19

84

19

86

19

88

19

90

19

92

19

94

19

96

19

98

20

00

20

02

20

04

Num

ber

0

100000

200000

300000

400000

Dragsey (outlet)

Helluvad (5 km)






53







ACKNOWLEDGMENTS





REFERENCES























54








29129-148















63417-426








53







ACKNOWLEDGMENTS





REFERENCES























54








29129-148















63417-426








54








29129-148















63417-426








xv international symposium on chironomidae for gislason and gardarsson.pdf · proceedings of the xv...

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