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Transcript of Evans Lake Erie HABs and Hypoxia - Great Lakes … k E i HAB d H iLake Erie HABs and Hypoxia:...
L k E i HAB d H iLake Erie HABs and Hypoxia:
Changing Nutrient Loading andIn-Lake Dynamicsy
Mary Anne EvansUSGS – Great Lakes Science Center
U.S. Department of the InteriorU.S. Geological Survey
The Team
J. David Allan, Kristin K. Arend, Steven Bartell, Dmitry Beletsky, Nate S. Bosch, Stephen B. Brandt, Ruth D. Briland, Irem Daloğlu, Joseph V. DePinto, David M. Dolan, Mary Anne Evans Troy M Farmer Daisuke Goto Haejin Han Tomas O Höök RogerMary Anne Evans, Troy M. Farmer, Daisuke Goto, Haejin Han, Tomas O. Höök, Roger
Knight, Stuart A. Ludsin, Doran Mason, Anna M. Michalak, J.I. Nassauer, R. Peter Richards, James J. Roberts, Daniel K. Rucinski, Edward Rutherford, Donald Scavia,
David J. Schwab, Timothy Sesterhenn, Hongyan Zhang, Yuntao Zhouy gy g
University of Michigan, Purdue University, Grace College, Ohio State University, Heidelberg University, University of Wisconsin-Green Bay, University of Wisconsin-Madison,
LimnoTech, Oregon State University, Korea Environment Institute, Carnegie Institute forLimnoTech, Oregon State University, Korea Environment Institute, Carnegie Institute for Science, Ohio Department of Natural Resources, USGS, NOAA
Physical Scientists, Ecologists and Chemists, Physical and Ecological Modellers, Engineers, Social Scientists, Practitioners
Lake Erie:Southern most, warmest, and most productive Great Lake
Recurrent HABs and Hypoxiaand Hypoxia
“Walleye Capital of the World”
Three goalsThree goals
• Both in lake and external loading changes• Both in lake and external loading changes matter
• Form of phosphorus matters
• Multiple causes and multiple effects must beMultiple causes and multiple effects must be considered to understand the system
Two modelsTwo models
area
??
??
ent Load
Hypo
xic ?
Conservation practicesHAB size
Nutrie
Nutrient Load
ractices
Fish populationConservation practices HAB size
ervatio
n pr
?
Conse
Two modelsTwo models
area
??
??
ent Load
Hypo
xic ?
Conservation practicesHAB size
Nutrie
Nutrient Load
ractices
Fish populationConservation practices HAB size
ervatio
n pr
?
Conse
Stumpf et al. 2012
Two modelsTwo models
area
?
?
?
?ent Load
Hypo
xic ?
Conservation practicesHAB size
Nutrie
Nutrient Load
ractices
Fish populationConservation practices HAB size
ervatio
n pr
?
Conse
Conservation practices
9
High‐resolution SWAT model the Sandusky WatershedSandusky Watershed
I. Daloglu
Observed DRP Load
6004‐year Moving Average
400
500
300
400
SRP (kg/year)
200
S
0
100
1970 1975 1980 1985 1990 1995 2000 2005 2010 20151970 1975 1980 1985 1990 1995 2000 2005 2010 2015
P. Richards
Calibrated and validated with observed Sandusky DRP loads
500
600
Ob d
Baseline400
500 Observed
ase e300 Baseline
Representative : ‐ Tillage practices‐ Fertilizer inputs
200
‐ Crop choices‐ Fertilizer timing‐ Soil P accumulation
i t il
100
in topsoil01970 1975 1980 1985 1990 1995 2000 2005 2010 2015
4 per. Mov. Avg. (Baseline‐KD8) 4 per. Mov. Avg. (Observed)
How about fertilizer use trends?
300 0
350.0
250.0
300.0
a
150.0
200.0
rtilizer inp
uts k
g/ha
100.0
Fer
0.0
50.0
1974‐1981 1982‐1986 1987‐1991 1992‐1996 1997‐2001 2002‐2006 2007‐2010
Han and Allan 2010
11‐52‐00 11‐52‐00 00‐15‐00
Fertilizer application rate scenario:Little impact on trend600
400
500Constant fertilizer
300
400
Baseline
200
100
01970 1975 1980 1985 1990 1995 2000 2005 2010 2015
4 per. Mov. Avg. (Baseline‐KD8) 4 per. Mov. Avg. (constantfertKD8)
Tillage practices scenario:Increased conservation tillageIncreased conservation tillage
Sandusky County Conservation Tillage
100000
Sandusky County Conservation Tillage
MTWH
40000
60000
80000
Acr
es
MTWH
NTWH
MTSB
NTSB
0
20000
40000A NTSB
MTCN
NTCN
1989 1991 1993 1995 1997 1999 2001 2003 2005
Tillage practices scenario:Appears to ha e some impactAppears to have some impact
600
400
500
100% notill
300Baseline
200
0
100
100% conventional
1970 1975 1980 1985 1990 1995 2000 2005 2010 2015
4 per. Mov. Avg. (Baseline‐KD8) 4 per. Mov. Avg. (convKD8)
4 per. Mov. Avg. (notillKD8)
Is this because of the P l ti t t il?
500
600 accumulation at topsoil?
400
Observed
300
200
Baseline
100
01970 1975 1980 1985 1990 1995 2000 2005 2010 2015
4 per. Mov. Avg. (Baseline‐KD8) 4 per. Mov. Avg. (Observed)
Is this because of the P accumulation at topsoil?accumulation at topsoil?
Surface application of P fertilizer and manureFertilizer application exceeding crop needsFertilizer application exceeding crop needs
Adoption of conservation tillageSoil stratification
Modified topsoil SRP: runoff concentration ratio in the SWAT model
600
the SWAT model
400
500
l
200
300
duce No‐Til
0
100
1970 1975 1980 1985 1990 1995 2000 2005 2010
Introd
Higher values allow phosphorus to accumulate at topsoill ll ff/ l b lLower values allow more P runoff/vulnerability
Simulated SRP Loadb f f
500
600Appears to be a significant factor
400
500
300
Constant PHOSKD
But …
100
200
Baseline
01970 1975 1980 1985 1990 1995 2000 2005 2010 2015
4 M A (B li KD8) 4 M A (b li )
Baseline
4 per. Mov. Avg. (Baseline‐KD8) 4 per. Mov. Avg. (baseline)
Lake Erie Extreme Precipitation
12
Sandusky Watershed
10
8
orm events
4
6
Num
ber o
f sto
2
N
0
1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 2015
Random weather scenario
450
500
A t l W th
350
400Actual Weather
250
300 Random Weather
100
150
200
0
50
100
1970 1975 1980 1985 1990 1995 2000 2005 2010 2015
Reversed weather scenario600 Weather matters, but interacts
with land‐based conditions
400
500
Actual Weather
R dW th
300
400 Reversed Weather
200
100
01970 1975 1980 1985 1990 1995 2000 2005 2010 2015
4 per. Mov. Avg. (Reversed weather) 4 per. Mov. Avg. (Baseline‐KD8)
Simulated SRP Load W t h dWatershed appears more vulnerable to weather impacts in
600
recent years.
Soil P accumulation
500 Observed
and tillage and fertilizing practices appear to underlie the 300
400
weather driver.
Change in overall 200
Baseline
fertilizer rates shift load but do not seem to drive the pattern.
100
01970 1975 1980 1985 1990 1995 2000 2005 2010 2015
4 per. Mov. Avg. (Baseline‐KD8) 4 per. Mov. Avg. (Observed)
Two modelsTwo models
area
??
??
ent Load
Hypo
xic ?
Conservation practicesHAB size
Nutrie
Nutrient Load
ractices
Fish populationConservation practices HAB size
ervatio
n pr
?
Conse
Thermocline Depth and Stratification Strength
‐2
3
D. Beletsky et al
y = 0 0109x + 16 977
‐7
y = 0.0264x ‐ 71.129²
y = ‐0.0109x + 16.977R² = 0.0363
‐12
R² = 0.1223‐17
‐22
1970 1975 1980 1985 1990 1995 2000 2005 2010
N l id h h 2005No clear evidence through 2005
Rucinski et al. 2010
Water Column Oxygen Depletion Rate
Rucinski, et al 2010
Water Column Oxygen Depletion Rate
DRP LoadDRP Load
O2 depletion rate
Rucinski et al 2010
Build Mixing Model2005
Diffusion
WCOD
2005
Epilimnion
SOD Model
Epilimnion
Hypolimnion
Data
Rucinski et al. 2010
Eutrophication Model
Rucinski et al. 2013
Model Calibration
Observations
Model
Rucinski et al. 2013
Model‐derived Response Curve Envelop encompasses interannual weather variabilityEnvelop encompasses interannual weather variability
46% reduction
Scavia et al. 2014
Model‐derived Response Curve Based on Dissolved Reactive Phosphorus (DRP)Based on Dissolved Reactive Phosphorus (DRP)
78% reduction
Scavia et al. 2014
Two modelsTwo models
area
??
??
ent Load
Hypo
xic ?
Conservation practicesHAB size
Nutrie
Nutrient Load
ractices
Fish populationConservation practices HAB size
ervatio
n pr
?
Conse
ance
n)
3.0
3.5
1987-2005S lt C i l Fi h i
elat
ive
abun
dabe
r / tr
awl m
i
1.5
2.0
2.5 R2 = 0.46 Smelt: Commercial Fisheries Hypoxia: Water Quality Model
Sm
elt r
e(n
umb
0.0
0.5
1.0
Hypoxia duration (days)40 50 60 70 80 90 100
t
10000
erci
al h
arve
stto
nnes
)6000
8000 1987-2005R2 = 0.64
Sm
elt c
omm
e(m
etic
t
2000
4000
Ludsin, Pangle et al. Hypoxia duration (days)40 50 60 70 80 90 100
S
0
Vertical Distributions under Strong Hypoxia
0Rainbow Smelt Yellow Perch
0
Daily Max.
DensityHypoxia OFF
10
5
75%
50%
OFF15
20
25%
0%
Depth (m) Multi‐species, 1‐D individual‐based modelHöök et al
Oxy‐thermal Squeeze0
Daily Max.
Rainbow Smelt, Strong Hypoxia, Baseline
5
yDensity
Temperature10
75%
Depth
15
50%(m)
Oxygen20
25%
0%Jun Jul Aug Sep Oct Nov
Multi‐species, 1‐D individual‐based modelHöök et al
Two modelsTwo models
area
??
??
ent Load
Hypo
xic ?
Conservation practicesHAB size
Nutrie
Nutrient Load
ractices
Fish populationConservation practices HAB size
ervatio
n pr
?
Conse
Three goalsThree goals
• Both in lake and external loading changes• Both in lake and external loading changes matter
• Form of phosphorus matters
• Multiple causes and multiple effects must beMultiple causes and multiple effects must be considered to understand the system