continued decline in lake erie water quality

CONTINUED DECLINE IN LAKE ERIE WATER QUALITY:

INCREASING CYANOBACTERIAL BIOMASSES OVER TIME (1996-2010)

Douglas D. Kane Defiance College

Joseph D. Conroy Division of Wildlife

Ohio Department of Natural Resources

David A. Culver The Ohio State University

R. Peter Richards, David B. Baker

Heidelberg University

The Overarching Issue

Lake Erie is impaired due to excessive loadings of sediment and nutrients.

Long-term water quality monitoring has identified the Maumee River as being the largest single contributor of non-point source pollution to the lake.

From- WLEB Partnership Website

Recent Lake Erie Re-Eutrophication

TRENDS (1970’s- 2000’s) – Total Phosphorus Loading – Phytoplankton Biomass- WB – Cyanobacterial Biomass- WB

Recent Lake Erie Re-Eutrophication

Year

1965 1970 1975 1980 1985 1990 1995 2000 2005

Ext

. Tot

al P

Loa

ding

(ki

loto

nnes

)

0

5

10

15

20

25

30

WB

Tot

al P

P W

et B

iom

ass

(g m

-3)

0

1

2

3

4

5

6

Lake Erie PP Trends: Western Basin

Year1965 1970 1975 1980 1985 1990 1995 2000 2005

Tot

al P

P B

iom

ass

(mg

L-1 )

0

1

2

3

4

5

6

7

FWMC vs. DRP

Observations

Total Phosphorus Loading not increasing, but

– Phytoplankton, Cyanobacterial blooms

– Soluble Reactive Phosphorus Loading

– And, » Dreissenid mussels now in the system » Mayflies have returned » Changing climate (i.e. more large storm events, warmer

winters etc.)

Hypothesis

Soluble Reactive Phosphorus Loading

LEADS TO Phytoplankton, Cyanobacterial blooms

Methods

SRP Load Determinations: NCWQR, HU Phytoplankton Biomass Determinations: LL, OSU Regression Analysis:

– Total PP/ Cyanobacterial Biomass vs. SRP – Cyanobacterial Biomass vs. Time

Results- Median Cyanobacterial Biomass vs. Corrected SRP Load (1996-2006)

Maumee R. SRP-load (metric tonnes)

0 250 500 750 1000

WB

Cya

no (

wet

mg

L-1)

0102030405060708090

100 P < 0.001 r2 = 0.80

Results- Seasonal Average Biomass vs. Uncorrected SRP Load (1996-2006)


0 100 200 300 400 500 600 700

WB

Tot

al P

P (

wet

mg

L-1)

0

10

20

30

40

50

60

70


0 100 200 300 400 500 600 700

WB

Cya

no (

wet

mg

L-1)

0

10

20

30

40

50

60

70

P = 0.008 r2 = 0.56

P = 0.008 r2 = 0.56

Results- Seasonal Average Biomass vs. Uncorrected SRP Load (1996-2006)


0 100 200 300 400 500 600 700

WB

Tot

al P

P (

wet

mg

L-1)

0

10

20

30

40

50

60

70


0 100 200 300 400 500 600 700

WB

Cya

no (

wet

mg

L-1)

0

10

20

30

40

50

60

70Maumee + Sandusky R. SRP-load

0 100 200 300 400 500 600 700 800

WB

Tot

al P

P (

wet

mg

L-1)

0

10

20

30

40

50

60

70

Maumee + Sandusky R. SRP-load

0 100 200 300 400 500 600 700 800

WB

Cya

no (

wet

mg

L-1)

0

10

20

30

40

50

60

70

P = 0.007 r2 = 0.57

P = 0.008 r2 = 0.56

Results- Seasonal Average Biomass (no >95% values) vs.Time (1996-2011)

Year

1996 1998 2000 2002 2004 2006 2008 2010

WB

Cya

no (

wet

mg

L-1 )

0

2

4

6

8

10

P = 0.006 r2 = 0.46

P = 0.002 r2 = 0.55

Western Lake Erie Waterkeeper Association

Conclusions

NASA

NASA

October 2011

September 2011

Reasons for SRP Increase??

DWWTP (Detroit Wastewater Treatment Plant) CSOs (Combined Sewer Overflows) CAFOs (Concentrated Animal Feeding Operations) UFOs (Unidentified Fertilizing Objects)

– Timing of Fertilizer Application – Rate “ “ – Type “ “ – Amount “ “

Exurbanization Septic Systems Saturated Filter Strips Climate Change All of These None of These

Acknowledgements

Dave Dolan- UWGB- Total Phosphorus Loading Data Limnology Laboratory Personnel- OSU National Center for Water Quality Research

Personnel- HU

continued decline in lake erie water quality

Education