A comparison of fish A comparison of fish quality in three different quality in three different

lakeslakes

By: Jorge Barbosa, Andrea Martin, By: Jorge Barbosa, Andrea Martin, Amanda Saralegui, and Chris “got Amanda Saralegui, and Chris “got

his butt kicked by Andrea” his butt kicked by Andrea” WhitmanWhitman

What we wanted to know…What we wanted to know…

• Does the presence of exotics result Does the presence of exotics result in an overall lower quality in the in an overall lower quality in the native fishnative fish

• Hypothesis: The condition of the Hypothesis: The condition of the native fish will be relatively poor in native fish will be relatively poor in the presence of introduced exotic the presence of introduced exotic species.species.

MethodsMethods

• Trap NetsTrap Nets• Minnow TrapsMinnow Traps• Seine NetsSeine Nets• Really AWFUL gill netsReally AWFUL gill nets• Eckman grabEckman grab• Plankton NetsPlankton Nets• MultiprobeMultiprobe• Secci DiskSecci Disk• LOTS of Time LOTS of Time

Size Range of Pumpkinseeds in Cranberry Lake

0

5

10

15

20

25

30

0-30 31-60 61-90 91-120 121-150 151-180

Size (mm)

Nu

mb

er o

f F

ish

Black Duck Hole (R)

West Flow (R)

Cat Bay (S)

East Inlet (S)

Joe Indian Cove (S)

Black Duck Hole (V)

Brandy Brook (V)

Size Ranges of Pumpkinseeds in Catlin Lake

0

5

10

15

20

25

30

0-30 31-60 61-90 91-120 121-150 151-180

Size (mm)

Nu

mb

er o

f F

ish

Catlin (R)

Catlin (V)

Size Ranges of Pumpkinseed in Cranberry Lake vs. Catlin Lake

0

10

20

30

40

50

60

70

80

90

0-30 31-60 61-90 91-120 121-150 151-180

Size Range (mm)

Nu

mb

er o

f F

ish

Cranberry Lake

Catlin Lake

Comparison Between Pumpkin seed in different habitats in Cranberry Lake

05

101520253035404550

1

Habitat

Ave

rag

e w

eig

ht

Rocky

Sandy

Veg

P = 0.258159

Length vs. Weight Regression of Pumpkinseeds in Cranberry vs. Catlin Lake

y = 2.8322x - 10.132

R2 = 0.9504

y = 3.2956x - 12.441

R2 = 0.9465

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

3.5 4 4.5 5 5.5

Natural Log of Length (mm)

Nat

ura

l Lo

g o

f W

eig

ht

(g)

Catlin Lake

Cranberry Lake

Linear (CranberryLake)

Linear (Catlin Lake)

t-Test: Two-Sample Assuming Unequal Variances

cranberry catlin

  Variable 1 Variable 2

Mean 10.24876 9.202674

Variance 26.10923 28.29012

Observations 149 57

Hypothesized Mean Difference 0

df 98

t Stat 1.276518

P(T<=t) one-tail 0.102395

t Critical one-tail 1.660551

P(T<=t) two-tail 0.204789

t Critical two-tail 1.984467  

Size Ranges of Red Breasted Sunfish in Catlin Lake

0

5

10

15

20

25

30

0-10

21-3

0

41-5

0

61-7

0

81-9

0

101-

110

121-

130

141-

150

161-

170

181-

190

201-

210

Szie Ranges (mm)

Nu

mb

er o

f F

ish

Rocky

Sandy

Vegetative

Size Ranges of Red Breasted Sunfish in Wolf Lake

0

10

20

30

40

50

60

70

80

0-10 11-20 21-30 31-40 41-50 51-60 61-70 71-80 81-90 91-100

101-110

111-120

121-130

Size Ranges (mm)

Nu

mb

er o

f F

ish

Rocky

Sandy

Vegetative

Size Ranges of Red Breasted Sunfish in Catlin vs. Wolf Lake

0

20

40

60

80

100

120

140

160

0-10

21-3

0

41-5

0

61-7

0

81-9

0

101-

110

121-

130

141-

150

161-

170

181-

190

201-

210

Size Ranges (mm)

Nu

mb

er o

f F

ish

Catlin

Wolf

Comparison of Red Breasted Sunfish at Rocky sites between Catlin and Wolf Lakes

0

5

10

15

20

25

1

Lake

Ave

rag

e W

eig

ht

Catlin Lake

Wolf Lake

P = 1.78E-7

Length vs. Weight Regression of Red Breasted Sunfish in Catlin vs. Wolf Lake

y = 0.3239x + 3.6972

R2 = 0.9453

y = 0.2872x + 3.8146

R2 = 0.94650

1

2

3

4

5

6

0 1 2 3 4

Natural Log of Weight

Na

tura

l Lo

g o

f L

en

gth

Catlin Lake

Wolf Lake

Linear (Wolf Lake)

Linear (Catlin Lake)

t-Test: Two-Sample Assuming Unequal Variances

Catlin Wolf

  Variable 1 Variable 2

Mean 9.202674 19.96216

Variance 28.29012 115.924

Observations 57 385

Hypothesized Mean Difference 0

df 137

t Stat -12.0489

P(T<=t) one-tail 1.51E-23

t Critical one-tail 1.656053

P(T<=t) two-tail 3.01E-23

t Critical two-tail 1.977432  

Comparison Between Average weight of some native fish in three lakes

010

2030

4050

6070

8090

1

Lake

Ave

rag

e w

eig

ht

Cranberry

Catlin

Wolf

P = 2.01E-12

Weight range of native and exotic species

0

100

200

300

400

500

600

700

800

0 500 1000 1500 2000

We

igh

t (g

)

Native Catlin

Exotic Catlin

Native Wolf

Overall ResultsOverall Results

• Competition with Exotic Species is Competition with Exotic Species is not the only factor that causes a poor not the only factor that causes a poor quality in native fishquality in native fish

• Other factors may include predation Other factors may include predation of small fish, poor quality of food, of small fish, poor quality of food, availability of food, spatial availability of food, spatial limitations, and human factorslimitations, and human factors

• We hate Wolf LakeWe hate Wolf Lake