San Francisco Bay Acts as a Reservoir and Mixing Bowl for Both Marine and. Freshwater Toxins. Raphael Kudela University of California Santa Cruz

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1 San Francisco Bay Acts as a Reservoir and Mixing Bowl for Both Marine and Raphael Kudela University of California Santa Cruz Cecile Mioni, Misty Peacock University of California Santa Cruz Tara Schraga USGS Menlo Park Dave Senn SFEI Freshwater Toxins

2 Source: Jim Cloern USGS time series Phytoplankton are a lot like red wine. If we have a glass each day, it s good for us, but if we drink a bottle a day, it s bad for us. There s some level at which the health of the ecosystem starts degrading. We re not at that point yet.

3 DATA SOURCES Phytoplankton species counts from USGS data ( ) m depth, chlorophyll > ~5 µg/l - Biased low for Microcystis SPATT (toxin) data from Underway flow-through on USGS cruises (surface) - Domoic Acid and Microcystins Ongoing/Future Work (in progress, not presented today) - Bivalve samples from two years - ~300 filters from USGS cruises

4 Data Summary, All Data HAB Data Percent HABs Unique Counts 16, % Unique Stations % Stations with HABs* % Stations with HABs* (April-November) %

5 Potentially Harmful Species Cell Counts and Biovolume Cell Counts H. Akashiwo Pseudo-nitzschia Karenia Dinophysis Karlodinium Akashiwo Alexandrium Anabaena Aphanizomenon Oscillatoria Planktothrix Synechococcus* 1E6 cells/l 1, 10, 100 E3 µm^3/ml H. Akashiwo Pseudo-nitzschia Karenia Dinophysis Karlodinium Akashiwo Alexandrium Anabaena Aphanizomenon Oscillatoria Planktothrix Synechococcus Year

6 Probability of an HAB in SFB 50% Probability 90 th Percentile of Chlorophyll Probability of observing any HAB species (Table 1) at concentrations higher than defined thresholds (Table 1) indicating potential impairment at USGS sampling stations (open circles) if specified value of chlorophyll is exceeded. Dashed lines are 95% confidence intervals of bootstrap (100 iterations) lower and upper confidence intervals. Note that as chlorophyll concentration increases, there is increasing variance in the probability. Red lines indicate the 90 th percentile of the historical chlorophyll data ( ) in San Francsico Bay, and the chlorophyll level at or above which there is a 50% probability of exceeding a HAB threshold. The red shaded area indicates the range of chloroohpyll (13-40 mg/m3) where there is a 50% probability of exceeding the HAB threshold when the upper 95% confidence interval is included. confidence

7 South Bay < > Central Bay South Bay An Area of Emerging Concern s18 s27 s32 s Dinophysis 30 35

8 South Bay < > Central Bay South Bay An Area of Emerging Concern s18 s27 s32 s Dinophysis Karenia 30 35

9 South Bay < > Central Bay South Bay An Area of Emerging Concern s18 s27 s32 s Dinophysis Karenia Karlo 30 35

10 Solid Phase Adsorption Toxin Tracking A simple and sensitive in situ (monitoring) method involves the passive adsorption of biotoxins onto porous synthetic resin filled sachets (SPATT bags) and their subsequent extraction and analysis. MacKenzie et al. (2004) Toxicon K Borchers / San Jose Mercury News M Roddam / UCSC M Roddam / UCSC

11 Why NOT use SPATT? Values are reported as mass toxin per gram resin, for some period of time. Difficult to directly compare to regulatory limits, which are typically based on grab samples or contamination of food products. Microcystin Grab Sample (ppb) Non-Detect 5-13 < 1 ppb SPATT (ng/g) 1< x < 10 ppb > 10 ppb Domoic Acid Mussel (ppm) SPATT (ng/g) *No statistical difference between 5-30 days 0-5 ppm ppm ppm >20 ppm >150

12 : USGS Deployment of SPATT October 2011 July Full-Bay cruises - 28 South Bay cruises % > 20 3% N.D. 28.5% >150 16% N.D. 3.5 % % 0-5 ng/g 61% Microcystins (>20 is high ) % Domoic Acid (>100 is high ) %

13 SPATT Microcystins Less Than 20 is low risk

14 SPATT Domoic Acid Less Than 100 is low risk

15 1 2 Toxins are prevalent in San Francisco Bay What Have We Learned? Persistence of both marine and freshwater toxins in the San 2 Francisco Estuary mixing bowl suggests we should pay more attention to HABs as indicators of water quality. Domoic Acid is probably introduced from Bay/coast exchange It is NOT clear that the Delta is the only/primary source of microcystins 4 South Bay may be exporting HAB species and is another source of microcystins

16 First-Order Question: Are HABs of concern in San Francisco Bay? HAB organisms are present ~35% of the time Chlorophyll values exceeding ~13-25 µg / L are reason for concern Microcystins and Domoic Acid are present nearly all the time - We DO NOT KNOW what chronic exposure means for water quality - We DO NOT KNOW if trophic transfer is significant - WE DO KNOW that toxins can exceed levels of concern/action Are HABs of concern in San Francisco Bay? Yes but we can t say yet how concerned we should be. Ongoing efforts as part of RMP, SFEI, USGS will answer some questions, including optimal monitoring and trophic transfer

17 Source: Jim Cloern USGS time series Phytoplankton are a lot like red wine. If we have a glass each day, it s good for us, but if we drink a bottle a day, it s bad for us. There s some level at which the health of the ecosystem starts degrading. We re not at that point yet. We ARE at that point (?)

18 Thank You! Collaborators: Dave Senn, SFEI Jim Cloern, USGS California Harmful Algal Bloom Monitoring and Alert Program Central and Northern California Ocean Observing System Funding: California Water Boards, RMP USGS San Francisco Estuarine Institute California Sea Grant/Ocean Protection Council Environmental Protection Agency More Information: