Download presentation
Presentation is loading. Please wait.
Published byFelicia Mathews Modified over 8 years ago
1
THE LONG HOT BLUE-GREEN SUMMER Jay Wright ODEQ - SEL
2
What are Blue Green Algae ? B LUE -G REEN A LGAE (BGA), technically known as C YANOBACTERIA Primitive, free-floating, microscopic organisms naturally present in reservoirs, lakes, and streams globally Have characteristics of bacteria (no organized nucleus) and plants (photosynthesis) Commonly found in low numbers but in warm, shallow, and undisturbed waters that receive large amounts of sunlight and overabundant nutrients, they can become abundant or “bloom”
3
Cyanobacteria = Blue-green algae = Cyanophyta Most of them have a pigment (phycocyanin) that gives them a blue-green color. Broadly divided into two main types: – Small, usually round cells, typically in colonies – Filamentous forms What are Blue Green Algae ?
4
Under certain environmental conditions, their populations can grow to very high levels (bloom) and can cause serious problems: 1.Some species produce very strong toxins. 2.They contain chemicals in their cell membranes which can cause severe dermatitis (swimmers itch) 3.When the numbers of algae (any algae) get too high, they can cause serious ecologic problems. Reduction in night time oxygen levels resulting on fish kills
5
Why should Oklahoma care about Blue Green Algae? H UMAN HEALTH EVENTS have been reported in: North America Africa Europe Australia Most reports are unsubstantiated or initially attributed to other causes. Pets and livestock have a high risk of suffering effects. D RINKING W ATER S UPPLIES ARE AT RISK … O KLAHOMA H AS 200+ S URFACE W ATER S UPPLIES
6
BGA Species Common in Oklahoma Anabaena Pseudanabaena Merismopedia Microcystis Oscillatoria Cylindrospermopsis Planktolyngbya
7
What do BGA Blooms Look Like? Spilled Paint
8
Pea Soup / Subsurface Blooms What do BGA Blooms Look Like?
9
Scums and Foam
10
Laboratory ID of BGAs Microscopy
11
Blue Green Algal Toxins Dermal Toxins – Lipopolysaccharides – Present in cell walls – Causes rashes, upper respiratory problems, gastroinestinal issues Neurotoxins Liver Toxins
12
Rash Flu-like symptoms – Nausea – Vomiting – Diarrhea – Upper Respiratory Neurological – Numbness – Weakness – Vertigo Abnormal Liver Profile Symptoms of BGA Toxin Exposure
13
Young – Increased incidental ingestion – Lower body weight Old Immunocompromised – Diabetes – Hepatitis – Recently ill Pets and livestock Who is most at Risk?
14
microcystin-LR anatoxin-a cylindrospermopsin saxitoxin
15
Microcystins Most commonly detected cyanobacterial toxin Water soluble, not absorbed through skin Liver is the ultimate target for toxic effects Highly toxic at low doses May act as a tumor promoter – Epidemiologic evidence linking liver cancer in patients with Hepatitis-B and drinking water contaminated with microcystins. Many (~70) different forms
16
Cylindrospermopsin Highly water soluble Stable in the environment Main target of cylindrospermopsin is the liver but can affect thymus, kidneys, lung, heart, intestinal tract A possible tumor initiator
17
Potency of Various Toxins ToxinAmount (mg) needed to kill a 220 pound person* Microcystin5-10 Cylindrospermopsin200-600 Nicotine100 Copperhead1100 King Cobra130-160 Diamondback Rattlesnake270-560 Botulinum toxin0.0001 *Based on the LD50 which is the amount of toxin that it takes to kill 50% of a test population. The smaller the number, the more potent the toxin.
18
BGA Toxin Testing ELISA Test – enzyme linked immunosorbent assay Tests for microcystin, cylindrospermopsin, saxitoxin. No test for anatoxin. Does not test for all variants of each toxin - can underestimate total toxin value Relatively inexpensive LC/MS/MS Tests for total toxins Expensive Requires dedicated, highly trained chemist
19
Recreational Advisory Levels LOW 20,000 cells/mL 4 ug/L Provide info to public, post ADVISORY 100,000 cells/mL 20 ug/L Restrict primary body contact, post WARNING MEDIUM HIGH Cyanobacterial scum formation N/A Consider further restrictions
20
Recreational Signage
21
Microcystin is on EPA’s Contaminant Candidate List for regulation WHO suggests a 1 ug/l (ppb) level for microcystin to protect long-term health Treatment techniques to reduce BGA Toxins – Use deepest intake level possible – No chlorine until after filtration – Optimize to maximize turbidity removal – Use GAC or PAC if possible – Ozonation as a disinfectant Public Water Supplies
22
Why do BGA Blooms Occur? Excessive Nitrogen & Phosphorus Agricultural Runoff Wastewater Treatment Plants and Septic Tanks Fertilizer Stormwater Runoff Weather Hot Dry Sunny Windless
23
When are Nutrients too High? Generally speaking…….. – Phosphorous levels in lakes greater than 0.05 mg/L (ppm) are considered too high. <0.02 mg/L is optimal. – Nitrogen levels in lakes greater than 1.0 mg/L (ppm) are considered too high. <0.5 mg/L is optimal. – When the nitrogen:phosphorous ratio is <15, this will favor the growth of blue-green algae.
24
2001 – Mozinga Lake in MO 2003 - Marion Reservoir in KS 2004 – 26 lakes in NE 2008 – RS Kerr Reservoir in OK BGA Blooms in the Area
25
NE Oklahoma 46,000 acres, 40 miles in length One of the premier recreational lakes in OK Managed by Grand River Dam Authority (GRDA) Can own lakefront property Shoreline is highly developed 11 public water supply intakes Grand Lake
26
Grand Lake Watershed
27
GRDA reports bloom on Friday, June 24 Advisory issued DEQ IDs microcystis GRDA tests for microcystin toxin – 1.5 to 2.5 X WHO warning level in grab samples – 12 to 18 X WHO warning level in scum samples Primary body contact prohibited Friday, July 1 Grand Lake BGA Timeline
28
Friday - June 24, 2011 Friday – July 1, 2011
29
Grand Lake BGA Timeline 6-24-2011
30
Grand Lake BGA Timeline 6-28-2011
31
Grand Lake BGA Timeline Wednesday June 29, 2011
32
Grand Lake BGA Timeline Thursday June 30, 2011
33
Grand Lake BGA Timeline Friday July 1, 2011
34
Grand Lake BGA Timeline Friday July 1, 2011
35
DEQ samples all PWS for microcystin – PWS samples show microsystin in 5 of 11 raw water samples at levels up 2.13 ug/l – All finished water samples are ND Bloom begins to ease July 4 Microcystin levels drop to ~ 1 ug/l by July 13 Primary body contact restriction lifted Public urged to use caution throughout the rest of the summer Continued monitoring showed < 1 ug/l microcystin Grand Lake BGA Timeline
36
Grand Lake BGA Bloom So What Happened? Flooding rains in May loaded the lake with nutrients 2 nd hottest June on record Normal conditions would have allowed reduction in nutrients by green algae August-like conditions and nutrients favor BGAs Site Total Nitrogen (mg/L) Total Phosphorous (mg/L)TN:TP Horse Creek – June 2422.82.738.4 Horse Creek – July 51.20.343.5 Duck Creek – June 2415.31.758.7 Duck Creek – July 52.00.613.3
37
2011 Oklahoma BGA Lakes Grand July 7 Grand July 7 Microcystis 14 WARNING Tenkiller July 14 Tenkiller July 14 17 ADVISORY WARNING ADVISORY WARNING Cylindrospermopsis Ft. Gibson July 7 Ft. Gibson July 7 Cylindrospermopsis Pseudanabaena Cylindrospermopsis Pseudanabaena 11 ADVISORY WARNING ADVISORY WARNING Keystone July 10 Keystone July 10 Ananaena Anabaenopsis Ananaena Anabaenopsis None ADVISORY WARNING CLOSURE ADVISORY WARNING CLOSURE Cylindrospermopsis
38
2011 Oklahoma BGA Lakes Eufaula July 19 Eufaula July 19 Planktolyngbya Cylindrospermopsis Planktolyngbya Cylindrospermopsis 14 ADVISORY WARNING ADVISORY WARNING Skiatook July 28 Skiatook July 28 Cylindrospermopsis 33 ADVISORY Hefner July 28 Hefner July 28 Pseudanabaena Planktolynbya Pseudanabaena Planktolynbya 11 WARNING Overholser July 28 Overholser July 28 Anabaena 11 WARNING
39
2011 Oklahoma BGA Lakes Texoma August26 Texoma August26 None Waurika August 19 Waurika August 19 Merismopedia 66 ADVISORY CLOSURE ADVISORY CLOSURE Cylindrospermopsis Pseudanabaena Cylindrospermopsis Pseudanabaena WARNING
40
2011 Blue-Green Algae Counts LakeOrganism# of cells/mL Grand LakeMicrocystis>200,000 Moderate Risk when >100,000 cells/mL EufaulaCylindrospermopsis57,000 Planktolyngbya36,000 Fort GibsonCylindrospermopsis58,000 Pseudanabaena90,000 KeystoneAnabaena2,317,000 Anabaenopsis1,109,000 OverholserAnabaena1,426,000
41
2011 Blue-Green Algae Counts LakeOrganism# of cells/mL WaurikaMerismopedia670,000 Moderate Risk when >100,000 cells/mL Cylindrospermopsis62,000 HefnerPseudanabaena264,000 Planktolyngbya74,000 Cylindrospermopsis52,000 TexomaCylindrospermopsis117,000 Planktolyngbya67,000 Pseudanabaena68,000 TenkillerCylindrospermopsis118,000
42
74 reports of illness possibly related to BGA exposure 56 have been interviewed – Grand Lake – 21 – Eufaula – 11 – Ft. Gibson – 7 – Keystone – 6 – Texoma – 5 – Hefner – 1 – Tenkiller – 1 Dates of Exposure: June 5 – August 28 Incubation Period – median of 1 day Syndromes – Upper Respiratory – 59% – Gastrointestinal – 50% – Rash – 30% – Neurological – 23% 27 received medical care, 1 hospitalized with pneumonia OSDH Health Statistics
43
Samples run – 67 ID and enumeration – 104 Toxin 250 calls from the public > 100 media calls ~150 original news stories 5 additional reports of BGA investigated Cumulative Efforts by DEQ
44
Planning Analytical Capacity Monitoring Funding Will this happen again? Unfortunately…
45
Know your watershed Support efforts to reduce nutrient inputs – Stormwater regulations – Effective wastewater treatment – Appropriate regulation of septic tanks – Agricultural BMPs – Monitoring efforts Make sure your PWS is operating efficiently What can you do?
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.