harmful algal blooms at surface water reservoirsnysawwa.org/docs/pdfs/session 8.3 hab.pdf ·...

Harmful Algal Blooms at Surface

Water ReservoirsStephanie A. Smith, Ph.D.

September 18, 2014

NY AWWA Tift Symposium

Liverpool, NY

HABs

• “Bloom” – overgrowth of algae, usually but not always visible

• “Algae”—often not true algae, but rather are cyanobacteria, a.k.a. “blue-green algae”

• “Harmful”—causing adverse ecological impacts and/or posing a potential threat to animal and human health

▫ Toxins are an obvious issue, but what about…

▫ Anoxic conditions that kill fish

▫ Deaths of pets, livestock

▫ Taste and odor issues in drinking water

▫ Sludge disposal—is it toxic?

▫ Economic damage at recreational lakes

Figure 3Paerl & Paul (2012) Water Research 46:1349-1363

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Figure 4Paerl & Paul (2012) Water Research 46:1349-1363

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Competitive advantages

• Growth at high temperature

• Buoyancy regulation

▫ Microcystis, Anabaena, Aphanizomenon, Planktothrix

• Nitrogen fixation

▫ Aphanizomenon, Nostoc, Cylindrospermopsin, Anabaena

• Toxin production?

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It’s Obvious, right?

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Or is it?

Photos courtesy of Steve Morton, NOAA

Or is it?

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Suspected Planktothrix rubescens, but turned out to be EuglenaHeather Raymond, OH EPA, 2012

P. rubescens and M. aeruginosaHeather Raymond, OH EPA, 2012

Or is it?

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Lyngbya, Julie Letterhos

http://www.epa.state.oh.us/portals/35/inland_lakes/PHOTO%20GALLERY%20OF%20OHIO%20HABs.pdf, Ohio EPA accessed February 2013

Cylindrospermopsis, Heather Raymond

Planktothrix, Linda Merchant-Masonbrink

HABs: The Toxins

• “Cyanotoxins”

• Hepatotoxins, neurotoxins, dermatoxins

• Acute or chronic

• One toxin can be made by multiple organisms

• One organism can make multiple toxins

• For any one toxin, there may be multiple structural types, or “congeners”

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HABs: The toxins

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microcystin nodularin

cylindrospermopsin

anatoxin

saxitoxin

Microcystin-LR

The Toxins

Toxin Organisms Target organ/system

Effects

Microcystin

Microcystis,Anabaena, Aphanizomenon, Anabaenopsis, Planktothrix

Liver

Abdominal pain, vomiting and diarrhea, liver inflammation, dermatitis, and more…

Anatoxin

Anabaena, Aphanizomenon, Cylindrospermopsis, Oscillatoria, Planktothrix

Nervous system

Neurotoxin; tingling, burning, numbness, drowsiness, slurred speech

Cylindrospermopsin

Cylindrospermopsis,Aphanizomenon, Umezakia, Lyngbya,Rhaphidiopsis, Anabaena

Liver See MC

Toxin potency

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Cyanotoxin LD50(ug/kg)

Comparison LD50(ug/kg)

Saxitoxins 10 Ricin 22

Anatoxin-a 200 Cobra venom 185

Anatoxin-a(S) 20 Sarin 218

Microcystin-LR 50 Curare 500

Cylindrospermopsin 300/180 Strychnine 2500/980

Hudnell (2010), Toxicon 55:1024-1034

Intracellular or Extracellular?

Healthy cells making microcystin or anatoxin-a

Healthy cells making cylindrospermopsin

Dying cells release toxins of any type

What’s a TPO to do?

• Define your goals

▫ For your source

▫ For your raw water intake

▫ For treatment

• Develop an approach to meet those goals

• Develop a contingency plan

Phycocyanin, chlorophyll, turbidity, etc.

Monitor

Microscopy, to look for toxic vs. nontoxic taxa of algae

Identify

Measure for algal toxins using test strips or ELISA

Measure

Limit nutrients, algaecides, natural products

Manage

Monitoring Tools

• YOUR EYES!

• Turbidity

• Temperature

• pH

• Dissolved oxygen

• Filter backwash—is it green?

• Taste & Odor—in summer?

• Fluorescent pigments

Principles of Fluorescence

Chlorophyll

Plants and green algae have chlorophyll

Principles of Fluorescence

Chlorophyll

Phycocyanin

Cyanobacteria (blue green algae) have phycocyanin + chlorophyll

Fluorometers• Used in a wide range of

applications

▫ microbiology, medical, WQ, molecular research, etc.

• Portable or Submersible

• Automated data logging

Google image search “handheld fluorometer”

Google image search “submersible fluorometer”

YSI

Portable Fluorometers

• Measure, PC, Chl, or both

▫ Changes in pigment reflect changes in population

▫ Establish a baseline, and monitor for changes

▫ No magic cutoffs!

Identify: Microscopy

• Different types of microscopes with different features

▫ Classical compound light, inverted, phase contrast, fluorescence…

▫ These are bacteria…need 100-1000X!

• Wide range in price

• Significant skill

Identify: Microscopy

Oscillatoria

Lyngbya

Identify: Microscopy

• Again, define your goals:

▫ Do you need full identification and enumeration of all taxa present, OR

▫ Do you just need to know if you have potentially toxic organisms to help decide whether you should test for toxins, OR

▫ Are you using this as a monitoring tool, and you are regularly looking for shifts in the population, OR

▫ Some combination of the above?

Phycocyanin, chlorophyll, turbidity, etc.

Monitor

Microscopy, to look for toxic vs. nontoxic taxa of algae

Identify

Measure for algal toxins using test strips or ELISA

Measure

Limit nutrients, algaecides, natural products

Manage

Microcystin International Guidelines

Country Limit Note…

Australia 1.3 ppb total microcystins

Canada 1.5 ppb MC-LR MAC

Czech Republic, China, Italy, Japan, Korea

1 ppb MC-LR, WHO provisional guidance

New Zealand 1 ppb Addresses 5 other toxins

Brazil 1 ppb Presumed total MC; has CYN and SAX guidelines, too

Spain 1 ppb Total microcystins

United State of America ??? ???

Cyanotoxins are not regulated in the

U.S.• Safe Drinking Water Act requires USEPA to

publish list of unregulated potential contaminants

▫ Contaminant Candidate List (CCL) #3 has

Anatoxin-a

Microcystin LR

Cylindrospermopsin

Cyanotoxins are not regulated in the

U.S.• However…2014 ASDWA Survey, 34 states

responding

▫ 5 have advisory thresholds for MC, 2 for additional toxins

▫ 6 have programs and policies, 4 have draft policies, 8 are discussing drafting policies

• General consensus—the regulations will be coming…

Holy Toledo!

• ADDA-ELISA detected >2 ppb in finished water

• USEPA, OEPA confirmatory testing with ELISA + LC/MS

• Is the WHO guideline the way to go, and if so, what does it actually mean?

Toxin Analyses

NMR LC/MS

TLC

Bioassay

ELISA

High sensitivityLow sensitivity

Low specificity

High specificity

HPLC

PPIA

ELISAs

• For water, by far the most popular

• Considered a screening tool

• A handful of popular commercial kits

▫ Abraxis

▫ Beacon

▫ Modern Water

▫ Envirologix

▫ Enzo Life Sciences (Abraxis?)

ELISAs

• Some limitations

▫ Antibody binding to an analyte, so actually an indirect measurement

▫ Cross reactivity of those antibodies with other things (low specificity)

▫ What are the antibodies binding to?

Does ADDA add up?

nodularin

Does ADDA add up?

• WHO guidelines and others were not based on ADDA or total microcystins, they were based on MC-LR, and LR only…

• Does this matter? Are the microcystins all the same?

LD50 -- ToxicityToxin LD50 (µg/kg) Animal Route ReferenceMC-LR 43.0 Mouse i.p. Gupta et al., 2003

38 ± 9 Mouse i.v. Kondo et al., 199236 (reported as ng/g) Mouse i.p. Stoner et al., 19895000 Mouse Oral Fawell et al., 199950-158 Mouse i.p. Fawell et al., 1999>5000 Rat Oral Fawell et al., 1999122 Rat (fed) i.p. Miura et al., 199172 Rat

(fasted)i.p. Miura et al., 1991

73 Mouse i.p. Watanabe et al., 1988MC-YR 110.6 Mouse i.p. Gupta et al., 2003

91 ± 2 Mouse i.v. Kondo et al., 199268 Mouse i.p. Watanabe et al., 1988

MC-RR 235.4 Mouse i.p Gupta et al., 2003600 Mouse i.p. Watanabe et al., 1988111 (reported as ng/g)

Mouse i.p. Stoner et al., 1989

MC-LA 39 (reported as ng/g) Mouse i.p. Stoner et al., 1989MC-LY 91 (reported as ng/g) Mouse i.p. Stoner et al., 1989

Phycocyanin, chlorophyll, turbidity, etc.

Monitor

Microscopy, to look for toxic vs. nontoxic taxa of algae

Identify

Measure for algal toxins using test strips or ELISA

Measure

Limit nutrients, algaecides, natural products

Manage

#1 Goal at the Source: Prevention

• Know your watershed, not just your water

• Preventing growth:

▫ Limit nutrient inputs

▫ Good aeration and mixing

▫ Flowing/movement of water

▫ Do copper or other treatments before the bloom?

• Preventing intake:

▫ Intake valves at different depths

▫ Rotation of reservoirs/more than one source

Manage the Source

• Copper is still the most popular

• Peroxide-based

• Alum treatment of reservoirs

• Is the toxin intra- or extra- cellular?

Intracellular or Extracellular?

Healthy cells making microcystin or anatoxin-a

Healthy cells making cylindrospermopsin

Dying cells release toxins of any type

Intracellular toxin (Intact Cells) Removal

Treatment Yay or Nay?

Pretreatment oxidation Nay

Coag/Sediment/Filtration Yay

Membranes Assumed Yay

Flotation/DAF Yay

Oxidation processes Nay

Extracellular Toxin (waterborne) Removal

Treatment Yay or Nay?

Membranes Maybe…

Potassium PermanganateYay for MC and Ana, not sure on

CYN

Ozone Yay for all

Chlorine dioxide Nay for acceptable DW doses

Chloramines Nay

ChlorinationYay for MC if pH is below 8,

ineffective for Ana

UV Radiation Yay, but really high doses

GAC/PAC Yay

Chlorination

pH MC-LR CT values in (mg x min)/L

ppb 10⁰C 15⁰C 20⁰C 25⁰C

6 50 46.6 40.2 34.8 30.8

10 27.4 23.6 20.5 17.8

7 50 67.7 58.4 50.6 44.0

10 39.8 34.4 29.8 25.9

8 50 187.1 161.3 139.8 121.8

10 110.3 94.9 82.8 71.7

9 50 617.2 526.0 458.6 399.1

10 363.3 309.6 269.8 234.9

Acero et al 2005

Chlorination

• For MC: pH below 7

• Saxitoxin, higher pH is better

▫ At pH 9 CT of 15

• Cylindrospermopsin

▫ CT of 15 at pHs above 6

• Anatoxin-a is not degraded by chlorine

• However, byproducts may have some toxicity in the case of cylindrospermopsin

Nicholson et al 2003; Senogles et al 2000; Carlile et al 1994; Shaw et al 2001

Carbon

• Generally effective for the extracellular toxins

• Challenge is disposal/regeneration

• Mesoporous for MC and CYN, micro for ANA

Management

• Must have a plan for response—just like any contaminant or contingency plan

• Must have a plan for public outreach and communication

▫ Frazil ice example from OH—very savvy usage of social media

In Summary…

• There are tools for dealing with HABs: Monitor/Identify, Measure, and Manage

• From a drinking water perspective, being reactive, rather than proactively monitoring and managing, can have serious consequences

In Summary…

• There needs to be consensus and leadership regarding how we handle HABs

▫ How to monitor and measure

▫ How to regulate/mitigate the causes

▫ How to build the foundation of understanding

• The situation we are in now reflects the paucity of research funding in this area for the last 25 years

▫ Reactionary funding does not solve problems!

Thank You

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