Post on 08-Jul-2020
transcript
Phytoplankton Response to Changing Nutrients from the
Comprehensive Everglades Restoration Plan: Comparison of Two Coastal Lagoon Systems in Northern
Florida Bay, USA
Yini Shangguan, Patricia M. Glibert,Jeff Alexander, Sue Murasko,
University of Maryland Center for Environmental Science, Cambridge, MD, USA
and Christopher J. MaddenSouth Florida Water Management District, West Palm Beach, FL, USA
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C‐111
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C‐111
Potential problems?
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C‐111Water flow => Nutrient regime change => Algal blooms
Florida Bay is a subtropical coastal lagoon• Shallow, highly enclosed, relatively quiescent, long residence time• High nutrient regeneration rate• Very sensitive to nutrients input
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Intermittent Closed Open Lakes and Lagoons (ICOLLs) in Northern Florida Bay• Sinks of land‐derived nutrients• Could be very ecologically productive ecosystem (Suzuki et al., 1998;
Menendez & Comin, 2000)
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• P‐limited system• Small‐sized phytoplankton are favored
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After CERP,• The nitrogen and phosphorus concentrations in northern Florida Bay will increase
• The phytoplankton abundance will increase and community composition will change
Hypothesis
Methods: Site Description
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Total Dissolved Nitrogen (TDN) (µM)
Total Dissolved Phosphorus(TDP) (µM)
Chlorophyll a(Chl a) (µg/L)
West Lake Chain (WLC) Eutrophic 119.19 0.66 36.94
Seven Palm Lake Chain (SPLC) Less nutrient‐rich 75.58 0.34 1.46
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Sampling collection• Apr 2010, Nov 2010, Apr 2011
• May 2013, Apr 2014
Chemical analysis• TND, TDP• Chl a, HPLC pigments
Data analysis• One‐way ANOVA at p= 0.1
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20
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60
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WLCBefore
WLCAfter
SPLCBefore
SPLCAfter
(µg/L)
Chlorophyll a
***
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0
50
100
150
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WLCBefore
WLCAfter
SPLCBefore
SPLCAfter
(µmol/L)
TDN
*
N decreased ,P increased, chlorophyll a declined in WLC while elevated slightly in SPLC
0.0
0.5
1.0
1.5
2.0
2.5
WLCBefore
WLCAfter
SPLCBefore
SPLCAfter
(µmol/L)
TDP *
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West Lake Chain Seven Palm Lake Chain
0.00.51.01.52.02.5
(µmol/L)
TDP
0.00.51.01.52.02.5
TDP
020406080100
(µg/L)
Chlorophyll a
0.01.02.03.04.05.0
Chlorophyll a
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(µmol/L)
TDN
0
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100
150
200TDN
* *
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West Lake Chain Seven Palm Lake Chain
0.00.51.01.52.02.5
(µmol/L)
TDP
0.00.51.01.52.02.5
TDP
020406080100
(µg/L)
Chlorophyll a
0.01.02.03.04.05.0
Chlorophyll a
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Biomass increased
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200
(µmol/L)
TDN
0
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100
150
200TDN
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In steady state• Biomass <= limiting nutrient• Growth rate <= flowFlow will flush cells out when dilution is higher than the maximum growth
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Chemostat model
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West Lake Chain
Seven Palm Lake Chain
Biomass, growth Nutrient, flow
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Seven Palm Lake Chain
P P N,P
N,PP P
West Lake Chain Biomass, growth Nutrient, flow
Seven Palm Lake Chain
P N,P
P
West Lake Chain Biomass, growth ent, flow
N,P
Seven Palm Lake Chain
P N,P
PP
West Lake Chain Biomass, growth ent, flow
Seven Palm Lake Chain
P N,P
PP
West Lake Chain Biomass, growth ent, flow
Seven Palm Lake Chain
P N,P
PP
West Lake Chain Biomass, growth ent, flow
0%
20%
40%
60%
80%
100%
**
Summary
N showed decreasing trend and P showed increasing trend
In the eutrophic WLC downstream, phytoplankton biomass was reduced while the phytoplankton community composition shifted. Phytoplankton cells might be flushed into Central Florida Bay.
In the less‐eutrophic SPLC downstream, phytoplankton biomass was enhanced while the community composition was unchanged.
If the flow after CERP is higher than maximum growth, cells in Northern Florida Bay will wash out into central Florida Bay.
If the flow is lower than maximum growth, the phytoplankton biomass in Northern Florida Bay will be determined by the limiting nutrient, P in the system.
Take Home Message
Acknowledgement• Field work
– Stefano Accoroni– Michelle Blaha– Stephen Kelly– Joseph Stachelek
• Analytical Service– Erica Kiss– Meg Maddox– Jennifer O’Keefe
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Z‐CU
SUM
Taylor Slough at mouth Water Level
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Z‐CU
SUM
Seven Palm Lake Salinity