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Cyanobacteria Ecological Strategies: Initiation, Development & Termination
of a Bloom
Barry H. Rosen, Ph. D.Florida Gulf Coast University
407-353-1541
Cyanobacteria
(aka blue-green algae; cyanoHABs)
•gram negative bacteria
•pigments in thylakoids
Ecological Strategy: Staying in the light (photic zone), but much more
Gas Vesicles: Buoyancy regulation and vertical migration
(C6H12O6)n
Low light
Nutrients scavenged whilst near
lake sediments or thermocline
Select genera
Ecological Strategy: gas vesicles
Ecological Strategies: morphology for staying in the water column
rarerare
Depiction of the primary producers (algae and cyanobacteria)
rarerare
Depiction of the primary producers (algae and cyanobacteria)
• Slow-growing nutrient specialist• Fast-growing nutrient
opportunist
• Variety of organisms, some common, some rare (why?) (how are some “holding on”?)
• At any given time, they experience approximately the same nutrient environment (although microhabitats exist)
• Daily, weekly, monthly, seasonal forcing functions (temp., light quantity and quality, rainfall)
• Each organism has an optimum rate of nutrient uptake; and optima for all other factors
• Each organism has a concentration threshold efficiency to take up that nutrient
Add a limiting factor
before afterrarerare
rarecommon
rarecommon
rarecommon
rarecommon
rarecommon
rarecommon
Some cells simply
increase in size
rare
• quiescent (subsistent) species stimulated
• rare species stimulated; more common species become rare (relatively)
Ecological Strategies: members of the community can overcome a limiting factor, like nitrogen limitation
• Lipid layer around cell wall• Loss of oxygenic-photosystem II• Visible pigment difference
Ecological Strategies: fix your own nitrogen from the atmosphere (the heterocyte)
Lake Okeechobee: (730 sq. miles) June progression of harmful algae bloom (NOAA)
Q: Where in the Lake Okeechobee do we see the blooms develop (monthly) and what are the suite of organisms that allow bloom formation? Do the current physical and chemical parameters explain the dynamics of these blooms?
Caloosahatchee-USGS S-79-monthly; intensified during a bloom
St. Lucie at S-308 , SFWMD/FDEP-monthly
SFWMD-collected 17 open water lake-monthly• whole water shipping to USGS • extensive water chemistry/physical
parameters by SFWMD
Caloosahatchee-SFWMD/FDEP at S-77-monthly
USGS Orlando
a. quantification and ID
b. culturingc. toxin gene screening d. toxin screening
Whole water shipping to USGS
USGS to CESU for metagenomics and 16s.
USGS to CESU for metagenomics and 16s.
USGS Orlando
a. quantification and ID
b. culturingc. toxin gene screening d. toxin screening
Partners: USGS (Ft. Myers, Orlando and KS), USACE, SFWMD, FDEP, universities
Testing: chemical and physical parameters, metagenomics, cyanotoxins-genes and toxins, and species ID and quantification
S-77
S-79S-80
S-308
Whole water shipping to USGS
St. Lucie at S-80 USGS-monthly
Cutting-edge approach with genetics
USGS installation
of mescosms
S-79
Q: Are macronutrients the maindriver in starting a bloom? Q: Do we see a response in the organisms: are toxin genes upregulated with these treatments? Q: Besides the bloom organism, how important are the other organisms in the water?
Partners: USACE, USGS, SFWMD, FDEP & universities
Testing: chemical and physical parameters, metagenomics, metatranscriptomics, proteomics, cyanotoxins, species, nutrient uptake, etc.
Year 2/3: refine experiment to focus on what was found in year one. May need to test other nutrients and elements like iron or other factors found from the complementary spatial survey.
Meta-transcriptomic and Proteomic Approach
Mesocosms1) pre-bloom “jumpstart” (using nitrate, ammonia or phosphorus)2) mid-bloom stimulation (same treatments)3) post-bloom “re-initiation”(same treatments)
Too much of a good thing?
Low dissolved oxygenleads to fish kills
Termination
“healthy colony”
Termination
Low dissolved oxygenleads to fish kills
Bacteria, predators, leaking cells, cell death, etc.
“healthy colony”
Termination
Low dissolved oxygenleads to fish kills
Bacteria, predators, leaking cells, cell death, etc.
DNA staining
showing interior
cells are protected
TerminationBacteria, predators, leaking cells, cell death, etc.
disaggregation consumers? Limiting factors
• Key nutrient (macro or trace element)
• Physical factor(s): light, temperature
• Natural succession
• Bacteria’s “hidden role”?
Termination
23
24
25
26
27
28
29
30
(5,000)
-
5,000
10,000
15,000
20,000
25,000
30,000
35,000
40,000
45,000
50,000
4/27 5/17 6/6 6/26 7/16 8/5 8/25
Num
ber
of
fila
men
ts/m
L
Tem
peratu
re (oC
)
Dolichospermum
Temp.
Copper sulfate treatments
Termination
phycoerythrinphycocyanin
Ecological Strategies: cyanobacterial art