20210602-002b: Update on Lady Bird Lake Harmful Algal Proliferation — original pdf

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The Lady Bird Lake Harmful Algal Proliferation - Update B r e n t B e l l i n g e r, P h . D . b r e n t . b e l l i n g e r @ a u s t i n t e x a s . g o v 5 1 2 - 9 7 4 - 2 7 1 7 J u n e 2 n d , 2 0 2 1 C I T Y O F A U S T I N W A T E R S H E D P R O T E C T I O N D E P A R T M E N T About Cyanobacteria “ B l u e - g r e e n A l g a e ” i s a b i t o f m i s n o m e r – t h e s e o r g a n i s m s a r e p h o t o s y n t h e t i c B a c t e r i a • Prokaryotic – loose nuclear material, organelles not bound • Can still find cyanobacteria genetic material within the chloroplasts of other algae and plants P r i m i t i v e ! • Over 3 billion years old F i r s t p h o t o s y n t h e t i c o r g a n i s m s ; c h a n g e d E a r t h ’ s a t m o s p h e r e l e a d i n g t o t h e f i r s t m a j o r e x t i n c t i o n T h e G R E AT O X Y G E N AT I O N E V E N T P r o d u c e a v a r i e t y o f s e c o n d a r y m e t a b o l i t e s i n c l u d i n g a s u i t e o f t o x i n s C I T Y O F A U S T I N W A T E R S H E D P R O T E C T I O N D E P A R T M E N T Cyanotoxin E(a)ffects N e u ro t o x i n s , H e p a t o t o x i n s E c o n o m i c P e rc e p t i o n D r i n k i n g wa t e r • EPA and State guidelines but they are Limited and Planktonic- focused C I T Y O F A U S T I N W A T E R S H E D P R O T E C T I O N D E P A R T M E N T Lady Bird Lake Event In July 2019, dogs became ill and died from toxic Cohesive Mats C I T Y O F A U S T I N W A T E R S H E D P R O T E C T I O N D E P A R T M E N T Who and What Identified: Phormidium and Geitlerinema • Known toxin producers Within algae mats dihydroanatoxin (dhATX) dominant • Anatoxin-a (ATX) potent neurotoxin “fast acting death • dhATX possibly 4x more toxic than ATX ?!?! (Puddick et factor” al. 2018) C I T Y O F A U S T I N W A T E R S H E D P R O T E C T I O N D E P A R T M E N T 2020 Toxin Content • Red Bud w/highest contents • However, visually, extent and biomass appeared lower in 2020 than 2019 Red Bud Auditorium Shores Mouth Shoal Creek Festival Ramp Site Range dhATX (mg/kg DW) Mean ± Std Dev dhATX (mg/kg) 0.0 – 132.7 0.0 – 5.7 0.01 – 4.1 0.0 – 3.2 15.1 ± 34.9 1.2 ± 2.2 0.9 ± 1.8 0.3 ± 0.9 C I T Y O F A U S T I N W A T E R S H E D P R O T E C T I O N D E P A R T M E N T Nutrients • Ammonia, TP elevated in 2019 (not shown) and 2020 Site NH3-N (μg/L) NO3 --N (μg/L) TN (μg/L) TP (μg/L) TN:TP Red Bud 53.3 ± 35.4 124.7 ± 126.8 544.8 ± 171.1 19.8 ± 14.3 91.3 ± 52.1 Barton Creek 26.3 ± 28.6 1,135.9 ± 457.9 1,538.1 ± 224.9 31.2 ± 34.9 229.3 ± 167.8 Auditorium Shores 29.4 ± 11.3 230.7 ± 120.8 688.5 ± 185.8 15.5 ± 12.5 140.6 ± 67.2 Mouth Shoal Creek 46.7 ± 21.9 383.8 ± 336.5 963.8 ± 400.8 49.1 ± 52.1 85.9 ± 84.4 Festival Ramp 33.4 ± 30.9 160.0 ± 76.9 630.9 ± 135.8 15.7 ± 11.3 127.5 ± 65.2 C I T Y O F A U S T I N W A T E R S H E D P R O T E C T I O N D E P A R T M E N T What Caused the Apparent Change in Lady Bird? A m o n g t h e d r i v e r s , A u s t i n i s a l wa y s h o t i n t h e s u m m e r, f l o ws a re a l wa y s ( re l a t i v e l y ) l o w i n J u l y / A u g u s t S o , i t m u s t b e t h e N u t r i e n t s ! • But not just the concentration (which were elevated) but also types; i.e., more NH3 and Phosphorus which cyanobacteria really like H y p o t h e s i ze t h a t ze b r a m u s s e l s a n d l a r g e s e d i m e n t d e p o s i t i o n e v e n t s d u e t o f l o o d i n g p r i m a r y d r i v e r s o f n u t r i e n t d y n a m i c c h a n g e s a t s e d i m e n t - wa t e r i n t e r f a c e C I T Y O F A U S T I N W A T E R S H E D P R O T E C T I O N D E P A R T M E N T The Mitigation Pilot Project Two-pronged approach to target Waterand Sediment nutrients Goa l: Red uce p hosp horus and hopefully ammonia ava ilable to cya noba cteria C I T Y O F A U S T I N W A T E R S H E D P R O T E C T I O N D E P A R T M E N T Sediment - Phoslock Re q u e s t i n g C o u n c i l A p p rova l f o r $ 3 0 0 k c o n t r a c t w i t h S e a P RO L a n t h a n u m - m o d i f i e d b e n t o n i t e ( ~ c l a y ) B i n d s i o n i c p h o s p h a t e s “ C a p s ” t h e s e d i m e n t s, s e q u e s t e r i n g P C I T Y O F A U S T I N W A T E R S H E D P R O T E C T I O N D E P A R T M E N T Water - Biochar C h a r c o a l p ro d u c e d by bu r n i n g o r g a n i c m a t t e r i n a b s e n c e o f ox yg e n Wo rk s l i ke a B r i t t a F i l t e r • Shown to reduce nutrient concentrations in ponds D e p l oy f i f t y ( 5 0 ) 2 ’ - l o n g b i o c h a r s o ck s o n t h e n o r t h a n d we s t s i d e o f Re d B u d I s l e HAP Site HAP Site “treatment site” C I T Y O F A U S T I N W A T E R S H E D P R O T E C T I O N D E P A R T M E N T “control site” ALI Site Monitoring M a t t ox i c i t y • Continue in collaboration with UT Wa t e r C h e m i s t r y • Will compare west side of Red Bud with the main-channel S e d i m e n t C h e m i s t r y bound (i.e., unavailable) • Sequential extraction procedure to verify P has moved from bioavailable to Lanthanum- Th i s i s a n ex p e r i m e n t a l a p p ro a c h t o s e e i f i t i s p o s s i bl e t o r e d u c e ex t e n t a n d m a g n i t u d e o f a t ox i c i t y eve n t • Continued presence of mats could still pose a risk C I T Y O F A U S T I N W A T E R S H E D P R O T E C T I O N D E P A R T M E N T Calendar of Events Environmental Commission, Council HAP Monitoring Pre/post Phoslock Monitoring Begin Monitoring Deploy Biochar Socks Phoslock Treatment #1 Phoslock Treatment #2 Phoslock Treatment #3 Sun Mon Tues Wed Thurs Fri Sat 30 6 13 20 27 4 11 18 25 8 15 22 29 5 Aug 1 31 7 14 21 28 5 12 19 26 2 9 16 23 30 6 June 1 8 15 22 29 6 13 20 27 3 10 17 24 31 7 2 9 16 23 30 7 14 21 28 4 11 18 25 8 Sept 1 July 1 3 10 17 24 8 15 22 29 5 12 19 26 2 9 4 11 18 25 2 9 16 23 30 6 13 20 27 3 10 5 12 19 26 3 10 17 24 31 7 14 21 28 4 11 C I T Y O F A U S T I N W A T E R S H E D P R O T E C T I O N D E P A R T M E N T Questions? Brent Bellinger, Ph.D. brent.bellinger@austintexas.gov 512-974-2717 C I T Y O F A U S T I N W A T E R S H E D P R O T E C T I O N D E P A R T M E N T