Harmful Algal Blooms (HABs) are a real problem for source water managers. Understanding what this problem is, being aware of when the problem exists and then being able to act on the problem before it is unmanageable is critical to the health of our water bodies. DR. Stephanie Smith, YSI Product Manager, is an expert on the issue, and here she shares some of her extensive knowledge regarding HABs, and some tips for how to proactively manage them. This is her presentation given at American Water Works Association.

1. Stephanie A. Smith, PHD
Stephanie.Smith@Xyleminc.com
November17, 2016 | AWRA, Orlando FL
Continuous Monitoring
for Harmful Algal Blooms

2. Harmful Algal Blooms (HABs)
Scope:
Freshwater cyanobacterial HABs
2
Photo credit:
Beagle Bioproducts, Inc.
Photo credit:
Ohio EPA

3. 3
For HAB Background:
http://info.xyleminc.com/2016-08-Profiler-Webinar_recording-LP.html
HAB Webinar

4. 4
Multiparameter
Water Quality
Monitoring
Monitor
Differentiate
PTOX from
non-PTOX
Identify
Measure for
algal toxins
(ELISA most
common)
Measure
Limit nutrients,
algaecides,
aeration, etc.
Manage
HAB Control Program

5. Monitor this… Because…
Chlorophyll Found in almost all algae
Phycocyanin Found specifically in blue-green algae
Temperature High temperatures favor cyanobacteria
pH ↑ pH due to high growth; makes CO2 more bioavailable
Turbidity A surrogate for increased biomass; may also be indicative of
nutrient-bearing suspended solids during runoff events
dO2 Decreases during a bloom; can lead to fish kills
Conductivity Blue-green algae generally thrive in lower conductivity
Algae
identification
Determine whether pigments/turbidity are due to potentially
toxic (PTOX) blue-green algae
Algal toxins Hazardous to human and animal health
Nitrogen and
phosphorus
Growth-limiting nutrients that stimulate blooms when in high
concentrations (eutrophic water)
5
HAB Monitoring

6. • Sensors for
• Turbidity
• pH
• Temperature / Conductivity
• dO2
• Central wiper to protect against
sensor fouling
• Internal or external continuous
data logging
• Total algae sensor (TAL)
• Chlorophyll
• Phycocyanin or phycoerythrin
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HAB Monitoring: EXO Sondes

7. 7
Everything that does
photosynthesis has
Chlorophyll
Chlorophyll

8. 8
Chlorophyll
Blue-green algae
have
Phycocyanin
Phycocyanin

9. 9
HAB Monitoring
Chlorophyll
Chlorophyll
Chlorophyll
ChlorophyllChlorophyll
= MORE ALGAE

10. 10
Sample Concentrate Extract Measure
HAB Monitoring: Chlorophyll

11. • Measure absorbance:
• Peak absorbance at 440
nm,
and lower absorbance
at ~660 nm
• Measure Fluorescence:
• Excitation with 440 nm light
• Peak emission at
~680 nm
Alcohol extraction doesn’t
work for PC & PE…
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Chlorophyll Measurement

12. 12
HAB Monitoring: Chlorophyll + PC
Chlorophyll
Phycocyanin
Chlorophyll
Chlorophyll
ChlorophyllChlorophyll
= MORE PTOX
BGA
PhycocyaninPhycocyanin
PhycocyaninPhycocyanin

13. 13
Waste heat
6 CO2 + 6 H2O C6H12O6 + 6 O2
Photosynthesis
(Resonance energy transfer)
Other Fates
• Pigment destruction
• Triplet state conversion
• Reactive Oxygen generation
Light
(Fluorescence)
Pigments & Photosynthesis

14. 14
Pigments & Photosynthesis

15. 15
FRET = Fluorescence Resonance Energy Transfer
Pigments & Photosynthesis

16. 16
Pigment Peak Ex ʎ Peak Em ʎ
Phycoerythrin 550 650
Phycocyanin 625 650
Allo-
phycocyanin
615,650 655
Chlorophyll 440, 662 680
Ideal scenario for
photosynthesis:
Where an accessory pigment
emits, chlorophyll absorbs
(FRET)
6-series: pigment-specific
excitation/emission
EXO: leverage FRET
Fluorescent Pigments

17. 17
Legacy 6-series:
Chlorophyll and
“BGA” PC or PE
EXO:
Total Algae (TAL)
Smart Sensors
HAB Sensors

18. • Chlorophyll sensor
• “BGA” sensor for
phycocyanin
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HAB Sensors: Legacy 6-Series

19. 19
HAB Sensors: Legacy 6-Series
590 nm
640 ± 40 nm

20. 20
HAB Sensors: Legacy 6-Series
470 nm
>590 nm

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470 nm
590 nm
685 nm
650 nm
Solid—excitation
Dotted--emission
HAB Sensors: EXO TAL-PC

22. HAB Sensors: The EXO Advantages
Feature Legacy 6-series
BGA-PC
EXO TAL-PC EXO Significance
Excitation LED Single (orange) Dual (orange + blue) Chl + PC response
Optical filter 640 ± 40 nm 685 ± 20 nm Less interference
Range 0-280,000 cells/mL
0 to 100 RFU
0 to 100 μg/L:
0 to 100 RFU
Units standardized
for all pigments
Resolution 1 cell/mL
0.1 RFU
0.01 μg/L;
0.01 RFU
10X better
Detection limit 0.1 RFU 0.01 RFU 10X better
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Better specificity + Better sensitivity
=
Earlier Detection
=
Better mitigation & management

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• Biology
• Intracellular pigment concentrations are not standard/constant
• Photoinhibition of chlorophyll
• In 6-series, some excitation of chlorophyll can occur with the PC
probe
• Temperature and fluorescence are inversely proportional
• Turbidity
• Absorbance and scattering in the water matrix
• “But I liked my cfu/mL on the 6-series!!”
All Sensors: What are you really measuring?

24. • TAL-PC or –PE are ideal for in situ
monitoring
• There is an EXO chlorphyll sensor
• Still better specificity than 6-series
• Know what you’re measuring
• RFUs
• Correlations work, but should be
interpreted with care
• Best management outcomes
leverage the platform
• Temperature, pH and turbidity
• Dissolved oxygen
24
EXO Smart Sensors: Recommendations

25. Questions? info@ysi.com
+1 (937) 767-2762
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