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Dynamics of cyanobacterial bloom formation Justin Chaffin Ph.D. F.T. Stone Laboratory Ohio Sea Grant The Ohio State University chaffin.46@osu.edu HABs 101 Tom Ridge Environmental Center, August 14, 2013
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What is a Harmful Algal Bloom? What is algae?
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“Algae” Algae is not a taxonomic term – Eclectic term referring to any photosynthetic organisms that lacks multicellular gametangia – Eukaryotic or prokaryotic – Autotrophic, heterotrophic, mixotrophic – Marine, Freshwater, or terrestrial Some reserve the term “algae” for only eukaryotic organisms – Excludes cyanobacteria
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There are hundreds of species of algae in Lake Erie
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Lake Erie Shallow (30 ft)Deep (210 ft) MuddyClear High NutrientsLow Nutrients Warm Cool High Productivity Low Productivity
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Lake Erie food web Bottom organisms
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Major phytoplankton groups in Lake Erie Diatoms Glass cell wall High lipid content Nutritional for zooplankton Spring blooms of diatoms in Lake Erie http://cfb.unh.edu/
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Lake Erie diatom bloom during winter Twiss et al., 2012 J Great Lakes Res.
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Major phytoplankton groups in Lake Erie Green Algae Closely related to higher plants Account for 50% of species in Lake Erie Rarely bloom Less lipid, but nutritious http://cfb.unh.edu/
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Cladophora Cladophora chloroplast Cladophora epiphytes Cladophora chloroplast
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Major phytoplankton groups in Lake Erie Cyanobacteria “Blue-green algae” Some contain gas vacuoles Some produce toxins Some fix nitrogen Low lipid, low nutrition Just a few are “Harmful” – Synechococcus ~ 50% of oxygen http://cfb.unh.edu/
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Other algae of Lake Erie http://cfb.unh.edu/phycokey/phycokey.htm
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Lake Erie produces the most fish of all the Great Lakes because it has the most algae Highest nutrient concentrations Warmest water temperature
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Too much of the wrong kind of algae is harmful “Bloom” is an excessive amount of algae “Harmful algae bloom” is a bloom of potentially harmful algae. Photo Credit: Drs Jeff Reutter and Doug Kane
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What is a Harmful Algal Bloom? Harmful = – Has the potential to produce toxins. – Harmful impacts on ecosystems Algal = – Blue-green algae (cyanobacteria) – Red tide (dinoflagellates) Bloom = – Biomass that far exceed normal Hungeree.com geology.com
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Are there non-harmful algal blooms? Cladophora Diatoms These algae can reach high biomasses but do not produce toxins harmful to humans or animals – But can have other negative impacts Turtles.org
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Not an algal bloom: Duckweed Lily pads Submerged plants Lawn clippings
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Algal blooms are a global problem Due to humans increasing nutrient loading Lake Taihu, China Lake Nieuwe Meer, Netherlands Lake Erie, USA
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Problems associated algal blooms “Blooms” of cyanobacteria – Produce toxins – Low diversity of phytoplankton Taste and smell problems Low dissolved oxygen Property value decreases Negative economic impacts whoi.edu, W. Carmichael geolocation.ws
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High phosphorus concentrations are required for eutrophication Schindler 1974. Science
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Bloom requirements Water temperatures > 15 °C – July, August, September in Lake Erie High nutrient concentrations – Run off associated with rain storms – Phosphorus typically is the “limiting nutrient” – Nitrogen is important in cyanotoxin production
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Lake Erie cyanobacteria blooms MODIS
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Lake Erie 2011
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Microcystis is the major blue-green algae in Lake Erie http://cfb.unh.edu/phycokey/phycokey.htm
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Microcystis http://cfb.unh.edu/phycokey/phycokey.htm
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Microcystis http://cfb.unh.edu/phycokey/phycokey.htm
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Anabaena common late summer http://cfb.unh.edu/phycokey/phycokey.htm
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Non-blooming Cyanobacteria in Lake Erie MerismopediaChroococcus http://cfb.unh.edu/phycokey/phycokey.htm
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Lake Erie blooms have been typically confined to western Lake Erie: Microcystis landsat
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Lake Erie 2011 A)June 1 B)July 19 C)July 31 D)August 11 E)September 3 F)October 9 Michalak et al. 2013 PNAS
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Variation in Microcystis bloom intensity of Lake Erie Bridgeman et al., 2013. Journal of Great Lakes Research
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2011 Record-breaking bloom explained
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Maumee River spring phosphorus load explains the size of the bloom Stumpf et al. 2012 PloS One
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Most P loading occurs during storms Michalak et al. 2013. Proc Nat Acad Sci
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Calm summer increased residence time of Maumee Bay Spring storm water sat in Maumee Bay during summer and provide the perfect incubator for cyanobacteria. Michalak et al. 2013. Proc Nat Acad Sci
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Calm water favors Microcystis Microcystis wins in calm water and deeper water Diatoms win in mixed water Huisman et al. 2004 Mixed Calm TurbidClear
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Photo credit: Roger Knight
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2011 Record-breaking bloom explained Many large spring storms High P loading – Fertilized growth Very calm early summer – Microcystis floated and thrived – Diatoms sank and died
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Other cyanobacteria blooms
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Sandusky Bay
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Planktothrix in Sandusky Bay http://cfb.unh.edu/phycokey/phycokey.htm
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Sandusky Bay – July 2012
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Central basin Anabaena bloom
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Benthic Lyngbya in Maumee Bay
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Lyngbya http://cfb.unh.edu/phycokey/phycokey.htm
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Lyngbya at Stone Lab. August 20 2012
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