Transcript LR-Chaffin-Erie-PA-8.. - Pennsylvania Sea Grant
Dynamics of cyanobacterial bloom formation Justin Chaffin Ph.D.
F.T. Stone Laboratory Ohio Sea Grant The Ohio State University [email protected]
HABs 101 Tom 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 chloroplast Cladophora epiphytes
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 geology.com
Hungeree.com
Are there non-harmful algal blooms?
• • Cladophora Diatoms Turtles.org
• These algae can reach high biomasses but do not produce toxins harmful to humans or animals – But can have other negative impacts
Not an algal bloom: • • • • Duckweed Lily pads Submerged plants Lawn clippings
Algal blooms are a global problem • Due to humans increasing nutrient loading Lake Erie, USA Lake Nieuwe Meer, Netherlands Lake Taihu, China
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 Dense algae bloom + Carbon + Nitrogen No 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 2011 A) June 1 B) July 19 C) July 31 D) August 11 E) September 3 F) October 9 Michalak et al. 2013 PNAS
40000 Variation in Microcystis bloom intensity of Lake Erie 35000 30000 25000 20000 15000 10000 5000 0 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012
Year
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
Clear
Huisman et al. 2004
Turbid
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