Blue Green Algae Appearance in Minnesota Lakes

Matt Lindon, Howard MarkusAnd Steve Heiskary

Outline

• Examples and Characteristics of Blue Green appearances in the field – Blue Green Clues and Characteristics– What is not Blue Green – Variation within lakes and through summer

• Little Rock Lake Example – Photos and results

Gelatinous

Filaments

Color

Caking

Foam Slurry

Mixed

Piling

Skin – Scums

On aquatic plants

Fish kills

“Duckweed”(not an algae)

Algae & other aquatic plants that might be mistaken for blue-green algae

Algae & other aquatic plants that might be mistaken for blue-green algae Continued.

Filamentous green algae – may form mats on surface

Chara, may float near surface; often found in lakes with high clarity.

Varies within a short time

North Phalen July 20th 06North Phalen July 16th 06

Varies through open water season

Near Shore Mid Lake

May

June

Nearshore Mid-Lake

July

Nearshore Mid-Lake

Early August

Nearshore Mid-Lake

Late August

Nearshore

SeptemberNearshore

Diatoms95%

Anacystis5%

Madison Lake May 2006

Madison Lake June 13 2006

Anabaena 5%

Anacystis10%

Aphanizomenon5%Microcystis

80%

Microcystis40%

Anabaena25%

Oscillayoria30%

Diatoms5%

Madison Lake Aug 8th 2006

Little Rock Lake• July 25, 2007 visit by Steve Heiskary, David Tollefson

and Harold Wiegner conducted sampling and observations;

• Response to numerous water quality complaints;• Strong wind from south by southeast so algae were

piling on the north and west shores.• Samples collected at four sites:

1. Lake access/beach area (north side)2. Little Rock Creek inflow3. West shore near 105th Ave.4. Little Rock Lake outlet at Highway 10 (south side)

• All four will be analyzed for microcystin and saxitoxin. Water samples to be analyzed for TP and chlorophyll-a at sites 1 and 4.

North

Little Rock Lake: 05-0013. Sample sites noted.

1

2 3

4

Benton County Beach and Lake Access area. Adjacent to site of sample #1

Beach

Little Rock Creek on North side; site of sample #2

Little Rock Creek backwater area

West shore @ 105th

- sample #3

Little Rock Lake Microcystin

120

38,00080,000

17 22

1

10

100

1,000

10,000

100,000

7/12/2007 7/26/2007 7/26/2007 7/26/2007 7/26/2007

LITTLE ROCK L. ROCK CK L. ROCK LK LITTLE OUT LITTLE ROC

µg/L

Little Rock Lake H2S Monitoring

0

5

10

15

20

25

30

35

40

31-J

ul1-

Aug

2-A

ug3-

Aug

4-A

ug5-

Aug

6-A

ug7-

Aug

8-A

ug9-

Aug

10-A

ug11

-Aug

12-A

ug13

-Aug

14-A

ug15

-Aug

16-A

ug17

-Aug

18-A

ug19

-Aug

20-A

ug21

-Aug

22-A

ug23

-Aug

24-A

ug25

-Aug

26-A

ug27

-Aug

28-A

ug29

-Aug

30-A

ug31

-Aug

1-Se

p2-

Sep

3-Se

p4-

Sep

5-Se

p6-

Sep

7-Se

p8-

Sep

9-Se

p10

-Sep

11-S

ep12

-Sep

13-S

ep14

-Sep

H2S

ppb

Air quality standard not to be exceeded more than two times in a five consecutive day period

Summary

• Appearance• Characteristics • What is not Blue Green

Algae • Little Rock lake example

Take home message

• Blue Green Algae can have a variety of appearances

• Good assessment can be beneficial – When to test – What message to give