PALEOLIMNOLOGY AS A LAKE
MANAGEMENT TOOL
Paul Garrison
Wisconsin Department
of Natural Resources
WHAT QUESTIONS CAN BE ANSWERED?
How has the water quality of my
lake changed?
Do we have more macrophytes
now than before?
Did we always have these algal
blooms?
HOW DO YOU COLLECT SEDIMENT CORES?
Gravity Corer
Piston Corer
WHAT INFORMATION IS RECORDED IN THE
SEDIMENTS?
•Geochemistry
•Nutrients -- phosphorus, nitrogen
•Soil erosion--aluminum, titantium
•Urbanization--zinc, copper
•Synthetic fertilizer--uranium, cadmium
•Anoxia--iron, manganese
•Diatoms
•Water quality history
•nutrients
•pH
•General aquatic plant growth
•Blue-green algae
•Plant remains
•History of macrophytes
Types of Cores
Full core
Top/Bottom
Modern
2000
1980
1960
1940
1920
1900
1880
1860
1840
1820
0.000
0.005
0.010
0.015
0.020
Reference
Lead-210 Dating
Lead Activity (pCi g-1)
0
222 Radon 210
Lead
0
5
222 Radon
10
Radium
15
Depth (cm)
226
238 Uranium
20
25
30
35
HALF LIVES
226 Radium 1024 yr
222 Radon 3.8 days
210 Lead
22.26 yr
40
45
50
1
2
3
4
5
FALLOUT FROM ATMOSPHERIC
BOMB TESTING
C
e
s
iu
m
D
a
tin
g
0
1
0
Depth(cm)
1
9
6
3
2
0
1
9
5
4
3
0
4
0
0
.0
0
0
.2
0
0
.4
0
0
.6
0
C
s
-1
3
7
:K
-4
0
0
.8
0
MACROPHYTE
CONTROL
GASOLINE
EMISSIONS
Arsenic
Western Basin
2000
1990
1980
1970
1960
1950
1940
1930
1920
1910
1900
1890
1880
1870
1860
0
2
4
Depth (cm)
6
8
10
12
1962
14
16
18
20
1975
0
0.0
0.5
1.0
Concentration (mg/g)
1.5
2.0
20
40
Lead Conc (mg/kg)
60
WHAT ARE DIATOMS?
9
10
BLUE-GREEN and GREEN ALGAE
11
AGRICULTURE
Circa 1880
Circa 1910
Green Lake
Titanium
Uranium
S
o
i
lE
r
o
s
i
o
n
Manganese
F
e
r
t
i
l
i
z
e
r
L
o
w
O
x
y
g
e
n
2
0
0
0
1
9
9
0
1
9
8
0
1
9
7
0
1
9
6
0
1
9
5
0
1
9
4
0
1
9
3
0
1
9
2
0
1
9
0
0
1
8
8
0
1
8
6
0
1
8
4
0
0
.
0
0
0
.
0
5
0
.
1
0
0
.
1
5 0
.
0
00
.
0
10
.
0
20
.
0
30
.
0
4 1
0
W
e
s
t
e
r
n
B
a
s
i
n
1
5
2
0
2
5
E
a
s
t
e
r
n
B
a
s
i
n
2
0
0
0
1
9
8
0
1
9
6
0
1
9
4
0
1
9
2
0
1
9
0
0
1
8
8
0
1
8
6
0
1
8
4
0
I
n
c
r
e
a
s
i
n
g
P
h
o
s
p
h
o
r
u
s
C
o
n
c
e
n
t
r
a
t
i
o
n
s
1
9
9
0
1
9
7
0
1
9
5
0
1
9
3
0
Phosphorus Distribution
Dane County - Farm 1
Soil Test Phosphorus (ppm)
140
120
100
80
60
40
20
0
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37
Number of Farm Fields
University of Wisconsin Nutrient and Pest Management
Program
AGRICULTURE CONVERTED
TO HOMES
Ashippun Lake
Ashippun Lake
2000
1980
1960
1940
1920
1900
1880
1860
1840
1820
2000
1980
1960
1940
1920
1900
1880
1860
1840
1820
0
20
40
60
-1
Inferred P (ug L )
80
0
20
40
60 -2
-1
Sedimentation Rate (mg cm yr )
80
SHORELAND DEVELOPMENT
SOUTHERN LAKES
Silver Lake
Silver Lake
2000
1980
1960
1940
1920
1900
1880
1860
1840
1820
2000
1980
1960
1940
1920
1900
1880
1860
1840
1820
2.0
2.5
3.0
3.5
4.0
Secchi (m)
4.5
5.0
0
20
40
60
-2
-1
Sedimentation Rate (mg cm yr )
80
Little Bearskin Lake
FERNLEAF PONDWEED
Present Day
circa 1930s
1800s
0
500
1000
1500
2000
2500
COONTAIL
Present Day
circa 1930s
1800s
0
500
1000
1500
2000
LARGE LEAVED PONDWEED
Present Day
circa 1930s
1800s
0
50
100
Number
150
g-1
200
250
Little Bearskin Lake
DIATOMS
Present Day2
Historical1
0
20
40
60
80
Percentage
Open-water
Macrophyte
100
Shift in the ratio of isoetids to elodeids
1930s: 50/50
2000s: 30/70
CLIMATE CHANGE
Huron Lake, Waushara County
26
Berry Lake
Dr. Samatha Kaplan—
UW Stevens Point
12,000 old
27
SUMMER PHOSPHORUS
60
50
Modern
Reference
40
Phosphorus
(ug L-1)
30
20
10
0
1
Shallow
2
Deep
3
Shallow
Headwater
4
Deep
Lowland
5
Shallow
6
Deep
Seepage
Drainage
28
SUMMARY
•Some lakes are naturally eutrophic. These lakes always are
drainage lakes and tend to be large and relatively shallow.
•Many lakes with significant agriculture in their watersheds
have experienced a reduction in soil erosion during the last
20 years but not necessarily a reduction in nutrient input
because of the use of synthetic fertilizers.
•In northern lakes that have experienced increased
shoreland development during the last 2-3 decades,
phosphorus levels may not have increased, but nearly all of
these lakes have experienced an increase in plant growth.
PALEOLIMNOLOGY AS A LAKE
MANAGEMENT TOOL
•How is the current lake condition different from
historical?
•If there has been a change, how much has it been
and what are the major causes?
•How much of an effort do we want to put into
improving our lake given fiscal and political costs?
LAKETIDES
Winter 2007
Winter 2008
31
•
•
•
•
•
•
Anvil Lake
Whitefish Lake
Rusk County Lakes
Rock Lake
Cloverleaf Lakes
Plum Lake
32
QUESTIONS?