Emily Runnells and Meghan Brown With Thanks To: ~Field and Lab Help: The Brown and Halfman Lab Crews...

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

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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