dynamics of cyanobacterial bloom formation justin chaffin ph.d. f.t. stone laboratory ohio sea grant...
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Dynamics of cyanobacterial bloom formation
Justin Chaffin Ph.D.F.T. Stone Laboratory
Ohio Sea GrantThe Ohio State University
HABs 101Tom Ridge Environmental Center, August 14, 2013
There are hundreds of species of algae in Lake Erie
Lake Erie food web
Bottom organisms
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/
Lake Erie diatom bloom during winter
Twiss et al., 2012 J Great Lakes Res.
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/
Cladophora
Cladophora chloroplast
Cladophora epiphytes
Cladophora chloroplast
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/
Other algae of Lake Erie
http://cfb.unh.edu/phycokey/phycokey.htm
Lake Erie produces the most fish of all the Great Lakes because it has the most algae
• Highest nutrient concentrations• Warmest water temperature
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
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
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
Not an algal bloom:• Duckweed• Lily pads• Submerged plants• Lawn clippings
Algal blooms are a global problem• Due to humans increasing nutrient loading
Lake Taihu, ChinaLake Nieuwe Meer, Netherlands
Lake Erie, USA
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
High phosphorus concentrations are required for eutrophication
+ Carbon+ Nitrogen+ PhosphorusDense algae bloom
+ Carbon+ NitrogenNo Phosphorus addedNo algae bloom
Schindler 1974. Science
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
Lake Erie cyanobacteria blooms
MODIS
Lake Erie 2011
Microcystis is the major blue-green algae in Lake Erie
http://cfb.unh.edu/phycokey/phycokey.htm
Microcystis
http://cfb.unh.edu/phycokey/phycokey.htm
Microcystis
http://cfb.unh.edu/phycokey/phycokey.htm
Anabaena common late summer
http://cfb.unh.edu/phycokey/phycokey.htm
Non-blooming Cyanobacteria in Lake Erie
Merismopedia Chroococcus
http://cfb.unh.edu/phycokey/phycokey.htm
Lake Erie blooms have been typically confined to western Lake Erie: Microcystis
landsat
Lake Erie 2011A) June 1B) July 19C) July 31D) August 11E) September 3F) October 9
Michalak et al. 2013 PNAS
Variation in Microcystis bloom intensity of Lake Erie
2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 20120
5000
10000
15000
20000
25000
30000
35000
40000
Year
Mic
rocy
stis b
iovo
lum
e (m
L/m
2/ye
ar)
Bridgeman et al., 2013. Journal of Great Lakes Research
2011 Record-breaking bloom explained
Maumee River spring phosphorus load explains the size of the bloom
Stumpf et al. 2012 PloS One
Most P loading occurs during storms
Michalak et al. 2013. Proc Nat Acad Sci
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
Calm water favors Microcystis
• Microcystis wins in calm water and deeper water
• Diatoms win in mixed water
Huisman et al. 2004
Mix
edCa
lm
TurbidClear
Photo credit: Roger Knight
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
Other cyanobacteria blooms
Sandusky Bay
Planktothrix in Sandusky Bay
http://cfb.unh.edu/phycokey/phycokey.htm
Sandusky Bay – July 2012
Central basin Anabaena bloom
Benthic Lyngbya in Maumee Bay
Lyngbya
http://cfb.unh.edu/phycokey/phycokey.htm
Lyngbya at Stone Lab. August 20 2012
Lyngbya at Stone Lab. August 20 2012