LR-Chaffin-Erie-PA-8.. - Pennsylvania Sea Grant

Report
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 epiphytes
Cladophora chloroplast
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)
geology.com
• Bloom =
– Biomass that far exceed normal
Hungeree.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 Erie, USA
Lake Nieuwe Meer, Netherlands
Lake Taihu, China
Problems associated algal blooms
• “Blooms” of cyanobacteria
– Produce toxins
– Low diversity of phytoplankton
•
•
•
•
whoi.edu, W. Carmichael
Taste and smell problems
Low dissolved oxygen
Property value decreases
Negative economic impacts
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)
B)
C)
D)
E)
F)
June 1
July 19
July 31
August 11
September 3
October 9
Michalak et al. 2013 PNAS
Variation in Microcystis bloom
intensity of Lake Erie
Microcystis biovolume (mL/m2/year)
40000
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
Calm
Mixed
• 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

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