Dynamics of cyanobacterial bloom formation Justin Chaffin Ph.D. F.T. Stone Laboratory Ohio Sea Grant The Ohio State University HABs 101 Tom Ridge Environmental Center, August 14, 2013

What is a Harmful Algal Bloom? What is algae?

“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

There are hundreds of species of algae in Lake Erie

Lake Erie Shallow (30 ft)Deep (210 ft) MuddyClear High NutrientsLow Nutrients Warm Cool High Productivity Low Productivity

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

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

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

Other algae of Lake Erie

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, China Lake 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 Schindler 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

Microcystis

Microcystis

Anabaena common late summer

Non-blooming Cyanobacteria in Lake Erie MerismopediaChroococcus

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 PNAS

Variation in Microcystis bloom intensity of Lake Erie Bridgeman et al., Journal of Great Lakes Research

2011 Record-breaking bloom explained

Maumee River spring phosphorus load explains the size of the bloom Stumpf et al PloS One

Most P loading occurs during storms Michalak et al 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 Proc Nat Acad Sci

Calm water favors Microcystis Microcystis wins in calm water and deeper water Diatoms win in mixed water Huisman et al Mixed Calm 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

Sandusky Bay – July 2012

Central basin Anabaena bloom

Benthic Lyngbya in Maumee Bay

Lyngbya

Lyngbya at Stone Lab. August