clancy brown william smith college rocky mountain biological lab mentor: brad w. taylor effect of...
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Clancy BrownClancy Brown
William Smith CollegeWilliam Smith College
Rocky Mountain Biological LabRocky Mountain Biological Lab
Mentor: Brad W. TaylorMentor: Brad W. Taylor
Effect of the nuisance diatom Effect of the nuisance diatom Didymosphenia geminataDidymosphenia geminata
on invertebrates on invertebrates in the East Riverin the East River
What is Didymo?What is Didymo?
Image: Sarah Kiemle, Michigan Tech University
Other diatom species; growing attached to stalk
Didymo stalk
Didymo cells
Blooms of Rock Snot?Blooms of Rock Snot?
Map: Sarah Spaulding, USGS
QuestionsQuestions
(1)Does D. geminata alter the composition and abundance of stream invertebrates?
(2) Does D. geminata affect the growth rate of stream invertebrates?
Removal PlotsRemoval PlotsUpstream
Downstream
8
2
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1 D
D
D
D
D
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I’m good at removing didymo!I’m good at removing didymo!
18-Jun 25-Jun 02-Jul 09-Jul 16-Jul 23-Jul 30-Jul
D.
gem
inat
a vo
lum
e in
dex
0
10
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Removal
D. geminata
D. geminata
Present Removed
Log[
dens
ity (
inse
cts/
m2 )
]
0
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8
Three invertebrate species showed Three invertebrate species showed habitat selectionhabitat selection
E. longimanusE. longimanus
ChironomidaeChironomidae
HesperoperlaHesperoperlapacificapacifica
Didymo has no effect on species Didymo has no effect on species richnessrichness
Two Experiments in the East River:Two Experiments in the East River:
Growth ChambersGrowth Chambers Baetis spp N = 6 chambers/treatment
Epeorus longimanus N = 9 chambers/treatment
Epeorus longimanusEpeorus longimanus shows a trend shows a trend towards slower growth rate in Didymotowards slower growth rate in Didymo
Didymo has no effect on the growth rate Didymo has no effect on the growth rate of of Baetis sppBaetis spp
Summary: Effect of Summary: Effect of D. geminataD. geminata on stream invertebrateson stream invertebrates
(1) Composition and abundance
- More Chironomidae and stoneflies (Hesperoperla), but fewer E. longimanus in D. geminata treatment
- No difference in species richness
(2) Growth rate
- A trend for slower growth in E. longimanus - No significant effect on Baetis spp
AcknowledgementsAcknowledgements
Brad W. TaylorBrad W. Taylor
The “Benthettes”The “Benthettes”
The National Science FoundationThe National Science Foundation
Rocky Mountain Biological LaboratoryRocky Mountain Biological Laboratory
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