the health of lake erie: past, present, and future · lake erie total phosphorus loading, 1967-2008...

The Health of Lake Erie: Past, Present, and Future

R. Peter Richards National Center for Water Quality Research

Heidelberg University Tiffin, Ohio

Lakeside, Ohio Chautauqua Lecture Series July 10, 2013

Outline • Lake Erie : The Lake that “Died”

• Lake Erie ecology 1900-1995

• Lake Erie ecology 1995-present

• Phosphorus inputs to Lake Erie and what to

do about them

• Predicting the severity of algal blooms

• What about the future?

• Conclusions

1. Lake Erie’s Pollution Woes

June 22, 1969

“I heard Lake Erie is the place fish go to die.”

- Johnny Carson, 1976

Gail Hesse, OLEPF

Even Dr. Seuss had something to say about Lake Erie…!

Gail Hesse, OLEPF

“They’ll walk on their fins and get woefully weary in search of some water that isn’t so smeary. I hear things are just as bad up in Lake Erie.”

http://en.wikipedia.org/wiki/File:The_Lorax.jpg Gail Hesse, OLEPF

What was wrong with Lake Erie?

Contaminated Harbors

•Oil and grease

•Phenols

•Iron and other metals

•PAHs

•PCBs

Contaminated Open Lake and Fish

• Mercury

• PCBs

• DDT, DDE

Lampreys

Alewives

Cladophora

Overfishing

•Blue Pike

•Walleye No more mayflies...

Hypoxia HABs

Causes of hypoxia

Toledo Buffalo epilimnion

hypolimnion

• A Central Basin problem

• Excess nutrient loading

• Thin hypolimnion

Some basic things about HABs

• Excessive algae reflect excess nutrients

• When an essential nutrient (N, P) gets used up, algal growth stops

• HABs can be reduced or eliminated by controlling phosphorus (P) [but nitrogen (N) is problematic]

• In the 1970s, most of the P came from sewage treatment plants

• At present, most of the P entering the Western Basin comes from the landscape - non-point source origin

• Most of the P entering the Central Basin comes from the Western Basin

Forms of P

(Total) Dissolved P • 90% of it is Dissolved

Reactive P (DRP)

• “Reactive” because…

Particulate P (PP)

Total Phosphorus (TP)

2. Eco-History to ca. 1995

Hypoxia increasing rapidly!

Modified from EPA-GLNPO

Pre-settlement hypoxia?!

Central Basin anoxia over time

0

10

20

30

40

50

60

70

80

1925 1935 1945 1955 1965 1975

% A

noxia

Western Basin Algae Problems

Microcystis


Cladophora

Remediation • Make phosphorus the limiting nutrient

• Set target load for P of 11,000 mta

• Reduce phosphorus inputs o Detergent phosphorus ban

o Sewage Treatment Plant upgrades

o Nonpoint source management • Fertilizer and manure management

• Erosion prevention – Conservation tillage

– Buffer strips

Looking for Signs of Success

Dai

ly d

isch

arge,

Mau

mee

Riv

er

Compared to short-term fluctuations, trends are quite subtle things!

Tributaries improved…

Maumee R.

Sandusky R.

0

25

50

75

100Suspended Solids

1975 1980 1985 1990 1995

0

0.1

0.2

0.3

0.4Total Phosphorus

1975 1980 1985 1990 1995

Maumee R.

Sandusky R.

0

0.025

0.050

0.075

0.100

0.125 Dissolved Reactive Phosphorus

1975 1980 1985 1990 1995

Maumee R.

Sandusky R.

…as did point source inputs.

0

5,000

10,000

15,000

20,000

25,000

30,0001967

1969

1971

1973

1975

1977

1979

1981

1983

1985

1987

1989

1991

1993

1995

1997

1999

2001

2003

2005

2007

An

nu

al

load

, m

etr

ic t

on

s

Direct Point Sources Atmospheric Deposition Lake Huron Input

Indirect Point Sources Tributary Monitored NPS only Adjustment for Unmonitored AreaLoad, all sources

Data from Dave Dolan, UWGB

Lake Erie Total Phosphorus Loading, 1967-2008

TP target load 11,000 metric tons

y = -0.0015x + 58.122

R2 = 0.0798

p=0.0003

0

5

10

15

20

25

30

35

40

1983 1985 1987 1989 1991 1993 1995 1997 1999 2001 2003 2005 2007 2009

To

tal

Ph

osp

ho

ru

s C

on

cen

trati

on

µg

/L

Central Basin Spring TP

Data from EPA-GLNPO

Central Basin Oxygen Depletion Rate

Using tentative alternate method, Rucinski et al. (in prep)

y = -0.283x + 564.87

R2 = 0.729

0.0

0.5

1.0

1.5

2.0

2.5

3.0

1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006

Wate

r C

olu

mn

Oxyg

en

Dem

an

d

mg

/L/

mo

nth

Dan Rucinski, LimnoTech


0

10

20

30

40

50

60

70

80

1955 1960 1965 1970 1975 1980 1985

% A

noxia

Anoxia decreasing again…

EPA-GLNPO

Success • By 1981, P target load (11,000 tonnes)

was met

• By mid 1990s: • Algal blooms greatly reduced

• Hypoxia greatly reduced

• Victory declared!

• …and we stopped looking. Bad idea!

3. Eco-History since 1995

And then it happened… The return of

It’s back?

EPA-GLNPO


0

10

20

30

40

50

60

70

80

90

100

1959 1969 1979 1989 1999 2009

% A

noxia

Chan

ge o

f bas

is f

or c

alcu

lati

on

Tributary P trends 1975-2007

Sandusky River data

y = -0.0015x + 58.122

R2 = 0.0798

p=0.0003

y = 0.0009x - 17.622

R2 = 0.0745

p<0.0001

0

5

10

15

20

25

30

35

40

1983 1985 1987 1989 1991 1993 1995 1997 1999 2001 2003 2005 2007 2009

To

tal P

ho

sp

ho

ru

s C

on

cen

trati

on

µg

/L

Central Basin Spring TP

Data from EPA-GLNPO

y = -0.283x + 564.87

R2 = 0.729

y = 0.0777x - 154.94

R2 = 0.689

0.0

0.5

1.0

1.5

2.0

2.5

3.0

1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006

Wate

r C

olu

mn

Oxyg

en

Dem

an

d

mg

/L/

mo

nth

Central Basin Oxygen Depletion Rate

Using tentative alternate method, Rucinski et al. (in prep)

?

Dan Rucinski, LimnoTech


Microcystis


Lingbya

Cladophora

Microcystis in Lake Erie The Microcystis-Anabaena bloom of 2009 was the

largest in recent years in our sampling region

2011

…until 2011


Tom Bridgeman, U. Toledo

Cladophora and noxious

“blue-green algae” are back

with a vengeance!

City of Toledo - $3000/day to

treat drinking water for

microcystin.

Microcystin 1000 ppb in

Western Basin, 2000 ppb in

Grand Lake St. Marys. WHO

recommendations 1 ppb for

drinking water (20 ppb for

swimming)

Where are the nutrients that

drive this coming from?

Increased Anoxia

Shift in lake response

y = -0.0015x + 58.122

R2 = 0.0798

p=0.0003

y = 0.0009x - 17.622

R2 = 0.0745

p<0.0001

0

5

10

15

20

25

30

35

40

1983 1985 1987 1989 1991 1993 1995 1997 1999 2001 2003 2005 2007 2009

To

tal

Ph

osp

ho

ru

s C

on

cen

trati

on

µg

/L

In-lake TP

y = -0.283x + 564.87

R2 = 0.729

y = 0.0777x - 154.94

R2 = 0.689

0.0

0.5

1.0

1.5

2.0

2.5

3.0

1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006

Wate

r C

olu

mn

Oxyg

en

Dem

an

d

mg

/L/

mo

nth

Water Column O2 Demand

WHY?

4. P Inputs to Lake Erie

0

5,000

10,000

15,000

20,000

25,000

30,0001967

1969

1971

1973

1975

1977

1979

1981

1983

1985

1987

1989

1991

1993

1995

1997

1999

2001

2003

2005

2007

An

nu

al

load

, m

etr

ic t

on

s

Direct Point Sources Atmospheric Deposition Lake Huron Input

Indirect Point Sources Tributary Monitored NPS only Adjustment for Unmonitored AreaLoad, all sources

Data from Dave Dolan, UWGB

Lake Erie Total Phosphorus Loading, 1967-2008

TP target load 11,000 metric tons

Western Basin Total Phosphorus Loading

Importance of DRP

(Total) Dissolved P • 90% of it is Dissolved

Reactive P (DRP)

• DRP is 100% bioavailable

Particulate P (PP) •~30% bioavailable

• Tends to settle to bottom

Tributary P trends 1975-2007

Sandusky River data

Importance of DRP

Dissolved P

• 90% DRP

• DRP is 100% bioavailable for algal growth

Particulate P

• ~30% bioavailable

• Tends to settle to bottom

But why has this happened?

Why has this happened?

• We know that sewage treatment plants are meeting their effluent limits and more

• => the problem is non-point source

• 80% of the drainage basin of Western Lake Erie is row-crop agriculture

• We can infer that the problem is related to crop farming

• … but how?!!!

Corn & soybeans Wheat

Soil Test Level

BuildupRange

MaintenanceRange

DrawdownRange

CriticalLevel

MaintenanceLevel

Fert

iliz

er

Ra

te 18%

50%

48%

33%

34%

17%

83%

P concentration in soil

P stratification in soil

Standard soil core - ideally 8” deep, Homogenized and measured for P content. Supposed to represent the “plow layer”

Split soil core - 0-2” and 2-8”, standard analysis of each part. What diference in P content is there with depth?

Zone of rainfall interaction with soil

P stratification in soil

Other factors - fall

application and weather

• Increasing trend to apply fertilizer/manure in fall/winter

• Often not incorporated

• Warmer winters => more rain, less snow and frozen ground => more P loss

• ≥50% of annual DRP load in three winter months

What can be done? • Know fertility levels and don’t over-apply

• Watch the weather and don’t apply when rain is likely

• Consider precision application, linked to yield variation within field

• Fertilize in spring if possible

• Incorporate fertilizer/manure!

• Don’t apply to frozen ground, especially on snow

• Consider winter cover crops

What else can be done?

• Improve sewage treatment, prevent CSOs

• Phosphorus-free lawn fertilizer or no fertilizer at all

• Phosphorus-free dishwasher detergent

• Find alternative to orthophosphorus for corrosion control in drinking water

Lost resources… • Nutrient losses from Maumee River

watershed, 2007: o P: 3,500 tons N: 29,600 tons

• Cost to replace them at 2008 prices: o P: $9,100,000 N: $57,500,000

• Cost per acre receiving fertilizer: o $62/acre

4. Predicting HAB Strength (Western Basin)

Concept • P loading drives algal growth

• HABs occur in late summer

• Perhaps P loads in some seasons are more important than loads in others.

• Relate “cyanobacteria index” (CI) to discharge and P loading

• CI best predicted by March-June discharge

• March-June TP and DRP also predictive

• Initial work done late in 2011 – can we predict 2012?

NOAA work

0.0

1.0

2.0

3.0

4.0

5.0

6.01975

1976

1977

1978

1979

1980

1981

1982

1983

1984

1985

1986

1987

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

2009

2010

2011

2012

Dis

ch

arg

e (

cu

bic

kil

om

ete

rs)

2011 and 2012 are the extremes - 2012 is 20% of 2011!

Spring Discharge (March-June)

NOAA Ecofore/Maumee Loads.xls

0

500

1000

1500

2000

25001975

1976

1977

1978

1979

1980

1981

1982

1983

1984

1985

1986

1987

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

2009

2010

2011

2012

TP

Lo

ad

(m

etr

ic t

on

s)

2011 and 2012 are extreme - 2012 is 17% of 2011!

Spring TP Load


0

50

100

150

200

250

300

350

400

450

5001975

1976

1977

1978

1979

1980

1981

1982

1983

1984

1985

1986

1987

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

2009

2010

2011

2012

DR

P L

oad

(m

etr

ic t

on

s)

2011 and 2012 are extreme - 2012 is 15% of 2011!

Spring DRP Load


2012 Forecast (mild bloom) and Observed Bloom

2012

Forecast

Measured

08/30/2012 (DOY=243)

09/03/2011 (DOY=246)

What about 2013? • Spring totals just completed at end

of June

• Predictions given last week at a webinar at Stone Lab

March-June Maumee Discharge

2.77

March-June Maumee Total P

1,099

March-June Maumee DRP

238

2013 Forecast: Significant bloom, similar to 2003, much milder than 2011

2013

2013 prediction for western Lake Erie similar in intensity to 2003,

<1/5 of 2011

low medium high

concentration

2013 may resemble 2003 2011 for comparison

NOAA Lake Erie Harmful Algal Bloom Bulletin, 2013, 5th year

Sign up to receive the weekly bulletin Search for NOAA Lake Erie Bloom Bulletin

5. What Does the Future Hold?

A look to the future • The crystal ball is murky, but…

• Projected increased intensity of storms will lead to increased erosion with associated loss of soil and attached nutrients

• Projected warmer winters may increase winter rain and loss of surface-applied nutrients

A look to the future • Warmer summers mean

• HABs starting earlier and perhaps lasting longer

• perhaps a thinner hyplimnion and longer stratified season, making hypoxia worse

• 2011 might represent a typical condition in the future, not an extreme one

• Things likely to get worse, not better, unless we redouble our efforts to limit nutrient inputs

Whew! Almost Done…

Summary • Excess nutrients are causing major

ecological problems in Lake Erie

• HABs in the Western Basin

• Hypoxia in the Central Basin

• Currently, the major source of excess nutrients is runoff from the land

• We fixed the problem once, but it has returned for changed reasons

• Future climate scenarios are discouraging unless we change our ways!

Useful References • Ohio Lake Erie Phosphorus Task Force

• http://www.epa.ohio.gov/dsw/lakeerie/index.aspx

• Paper on climate change, Lake Erie, and water sustainability • Anna Michalak and many others including me, Proceedings

of the National Academy of Sciences

• http://www.pnas.org/content/110/16/6448

October 7, 2011

Useful References • Ohio Lake Erie Phosphorus Task Force

• http://www.epa.ohio.gov/dsw/lakeerie/index.aspx

• Paper on climate change, Lake Erie, and water sustainability • Anna Michalak and many others including me, Proceedings

of the National Academy of Sciences

• http://www.pnas.org/content/110/16/6448

the health of lake erie: past, present, and future · lake erie total phosphorus loading, 1967-2008...

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