Barry Biggs National Institute of Water & Atmospheric Research · National Institute of Water &...
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Barry Biggs National Institute of Water & Atmospheric Research For the ‘Rock-snot team’ The Didymo Science Story (in part)
Transcript of Barry Biggs National Institute of Water & Atmospheric Research · National Institute of Water &...
Barry Biggs
National Institute of Water & Atmospheric Research
For the
‘Rock-snot team’
TheDidymo Science Story
(in part)
Outline
• What is the problem?• Where does didymo do best?• Some didymo biology• Overview of BioSec NZ sponsored science
programme• Vectors – in brief• Control possibilities
Courtesy of
Southland Fish & Game
What is theproblem ?
- A worst case bloom
0
100
200
300
400
Ash
-fre
e dr
y w
eigh
t (g/
m2 )
1993
2001200220042005
199719992000
It grows in very large masses in clean waters….trophic cascade of effects
What is the problem?
Biomassguidelinefor fish2006
Lower Waiau River, Southland Didym
o arrived
Courtesy of Meridian Energy
Courtesy of
Southland Fish & Game
Waiau River trout abundance - Excelsior Creek
0
20
40
60
80
100
120
140
160
180
1996 1997 1998 1999 2000 2001 2002 2006
Tro
ut p
er k
m
Brown Trout
Rainbow TroutIncrease in f low Didymo discovery
What is the problem?
Courtesy of
Southland Fish & Game
What is theproblem?
Courtesy of
Southland Fish & Game
What is the problem?
• Hydraulic habitat preferences
0.0 0.3 0.6 0.9 1.2 1.5Water velocity at 0.6 depth (m/s)
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500
Where does didymo do best?
Bio
volu
me
inde
x
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100
200
300
375
Sep-2004 Oct-04 Nov-04 Dec-04 Jan-05 Feb-05 Mar-05 Apr-05s ite 79719
Flo
w r
ecor
ded
at M
LC (
m3 /
s)P
eriphyton cover index (max. 300)
Didymo mat sloughing; overgrown with black cyanobacterial mat
No bed movement Didymo dominating, but “medium mats”remnants
Mostly Didymo remnants
300
200
100
0
Jericho
�� Stable river bedsStable river beds
Where does didymo do best?
Courtesy of Meridian Energy
Some didymo biology
Prof. M. Gretz, Michigan Tech.
Some didymo biology
Prof. M. Gretz, Michigan Tech.
Some didymo biology
Overview of BioSec NZ sponsored science programme
– Monitoring • Cathy Kilroy - NIWA
– Detection• Craig Cary – Waikato Uni
– Delimitation• Maurice Duncan - NIWA
– Ecology II• Scott Larned - NIWA
– Trout • John Hayes - Cawthron
– Survival• Cathy Kilroy - NIWA
– Control• Barry Biggs - NIWA
UnderstandingDistribution
UnderstandingImpacts
Containment&
Control
Vectors – in brief
• Inter-catchment– Fishermen– Kayakers– Jet boaters– Hydro generation– Irrigation
• Intra-catchment– Fish– Birds– Vehicles– Hydro generation– Irrigation
Vectors – in brief
felt_sole
gumboot
leather_boot
neoprene0
10000
20000
30000
40000
50000Li
ve d
idym
o c e
lls p
er it
em
After 5 hr ‘drying’
felt_sole
gumboot
leather_boot
neoprene0
100
200
300
400Li
ve d
idym
o ce
lls p
er i t
em
After 36 hr ‘drying’
But, decontamination chemicals did not penetrate felt material!!
Vectors – in brief
Control possibilities
• Attacking the stalks – Stalk degradation (Prof. M. Gretz – Mich. Tech)
• Attacking the growing cells – Biocides toxic to didymo (NIWA)
-20
0
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120
0 1 2 3 4 5 6
Time (hours)
% S
talk
Mas
s Lo
ss
Trifluoroacetic acid - RHS(1)
Penicillium enzymes (non-buffered) - RHS(1)Penicillium enzymes (non-buffered) - FD(2)Penicillium enzymes (pH 5) -FD(2)DH20 w/ Steam - FD(2)
NaOH w/ Steam - FD(2)
Penicillium enzymes (pH 5) -Fresh(3)EDTA - FD(2)
Hot Water - FD(2)
Loss of stalk material as a function of treatment
Attacking the stalks
Longer termCell toxicant10 ppmGermanium
Longer termExfoliation & degradation10 ppmEDTA
Longer termPhotosynthetic inhibitor1 ppmHydrothol
ImmediatePhotosynthetic inhibitor1000 ppmOrganic Interceptor
ImmediateCell toxicant10 ppmZinc sulphate
ImmediateMetabolic inhibitor1 ppmSimazine
ImmediateMembrane disruption20 ppmQAC
ImmediatePhotosynthetic inhibitor5 ppmDiquat
ImmediatePhotosynthetic inhibitor5 ppmCopper compound
ImmediatePhotosynthetic inhibitor5 ppmChlorine
Response timeMode of actionConcentrationBiocide
Biocide screening
Attacking the growing cells
Biocide screening
Attacking the growing cells
Monowai Experimental Facility (MEF)(at Monowai Power Station)
• Testing facility
4 Biocides @ 3 concs.
1 hr exposures
Application method
Fish added to channels as a toxicity assay
Daphnia magna used in laboratory toxicity testing
•Additional toxictyassaysMultipipettor being used during toxicity sampling
Attacking the cells -Ideal Ecotox Profile
Biocide Concentration (mg/L)
0 20 40 60 80 100 120 140
% S
urvival
0
20
40
60
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120
Fish
Invertebrates
Algae
Didymo
Concentration (mg Cu/L)
0 2 4 6 8 10
Sur
vivo
rshi
p
0.0
0.2
0.4
0.6
0.8
1.0
Didymo
Invertebrates
Algae
Fish-channels Fish-Lab data
Attacking the cells –Results of Gemex TM
Where to from here?
• Devel rapid response strategy for new incursions (eg, for Tongariro) (completed)
• Short-term management– Product formulation/toxicity (started)
– Small stream field testing (trials designed, consents being applied for)
– Design short-term control/application strategies (started)
• Long-term management– Product formulation/toxicity– Application strategies– Design long-term control strategies
Acknowledgements
particularly Christina Vieglais
particularly Bill Jarvie and Stu Sutherland
particularly Peter Mulvihill and Warren Greene
Meridian Energy particularly Dave Herrick
