Emily Runnells and Meghan BrownWith Thanks To:
~Field and Lab Help: The Brown and Halfman Lab Crews
~Funding: Senator Nozzolio and the State of NY, and Hobart and William Smith
Owasco Lake• Relative to other
Finger Lakes– Large watershed– Small volume– Poor water quality
• Recently,phytoplankton blooms and macrophyte growth increasingly common
• 2007 ~2 μg/L Chl a
Chlorophyll
Asterionella
www.fingerlakes411.com/listing.asp?
Why Monitor with Zooplankton?
Phytoplankton
Carnivorous Zooplankton
Forage fish
Sport fish
Herbivorous Zooplankton
Nutrients
Measures of
Productivity
LOW HIGH
Secchi Transparency
Several meters, usually into the hypolimnion.
Few meters, in the epilimnion.
Chlorophyll a Less More
ZooplanktonLow density
Selective feeders
High density
Tolerant of lower quality food
The Questions Asked:
• Does zooplankton composition data agree with other data measuring productivity in Owasco Lake?
• Does zooplankton composition analysis indicate increased productivity of Owasco Lake? ?
= =
Sampling
Secchi Zooplankton Chl a
Composition of Major Zooplankton Groups
0%10%20%30%40%50%60%70%80%90%
100%
5/18
/200
7
5/25
/200
7
6/1/
2007
6/8/
2007
6/15
/200
7
6/22
/200
7
6/29
/200
7
7/6/
2007
7/13
/200
7
7/20
/200
7
Calanoid Abundance
Cyclopoid Abundance
CladoceranAbundance
Low
Pro
duct
ivity
Hig
h P
rodu
ctiv
ity
May June July
Gannon Index =Σ Calanoid
Σ (Cyclopoid + Cladocerans)
Station 1: Productivity Measures
0
1
2
3
4
5
6
75
/18
/20
07
5/2
5/2
00
7
6/1
/20
07
6/8
/20
07
6/1
5/2
00
7
6/2
2/2
00
7
6/2
9/2
00
7
7/6
/20
07
7/1
3/2
00
7
7/2
0/2
00
7
-0.001
0
0.001
0.002
0.003
0.004
0.005
0.006
0.007
0.008
Station 1: Productivity Measures
Gan
no
n
Sec
chi
Dep
th (
m)
Ch
l a
(μg
/L)
May June July
Σ Calanoid
Σ (Cyclopoid + Cladocerans)
0
1
2
3
4
5
6
7
5/18
/200
7
5/25
/200
7
6/1/
2007
6/8/
2007
6/15
/200
7
6/22
/200
7
6/29
/200
7
7/6/
2007
7/13
/200
7
7/20
/200
7
-0.001
-0.0005
0
0.0005
0.001
0.0015
0.002
0.0025
Station 2: Productivity MeasuresC
hl
a (μ
g/L
)
Sec
chi
Dep
th (
m)
Gan
no
n
May June JulyΣ Calanoid
Σ (Cyclopoid + Cladocerans)
And so….
• Does zooplankton composition data agree with other data measuring productivity in Owasco Lake?
•Yes and No
•Sometimes agreement
•Not consistently one parameter that is out of line
• Does zooplankton composition analysis indicate increased productivity of Owasco Lake?
►Yes: May and July►Overall lake has moderate productivity
•More Bosmina than Daphnia•More cyclopoid than calanoid