climate and harmful algal blooms in lake erie · 2013. 12. 20. · stumpf et al. 2012 ....

Climate and Harmful Algal Blooms in Lake Erie

Lake Erie 22 July 2011

Richard P. Stumpf NOAA

National Centers for Coastal Ocean Science Silver Spring, MD

2013 Nov Climate NOAA Coastal Ocean Science

2003, “perhaps the most severe in Lake Erie’s recent history” (EPA)

2011 cyanobacteria bloom, worst in decades, visible from space

09 October : Data from MERIS (European Space Agency)


2012 bloom wasn’t.

10 September, data from MODIS


Potential (Large) Areas of Concern in Great Lakes

Green Bay

Saginaw Bay

Western Lake Erie

2008 bloom intensity

low high 105

cells ml-1 106 104


MERIS on the ENVISAT-1 satellite

1150 km

ENVISAT-1

Coverage every 2 days from 2002 to April 2012 launch of replacement (Sentinel-3) late next year


satellite algorithms (MERIS data) Standard blue-green algorithms are sensitive to absorption by many components.

We use Red/NIR and curvature (shape); insensitive to sediment and CDOM


MERIS can see more wavelengths of light, allowing us to detect and quantify blooms

13 Sep 2010

True color, difficult to identify and quantify

Red and near-infrared wavelengths help


This information gives a cyanobacteria index, “CI”, which equates to concentration

True color

Cyano Index (CI)

13 Sep 2010

low high 105

cells ml-1 106 104


Bulletins for Lake Erie bloom To get bulletin, search for “NOAA Lake Erie bloom bulletin” Transports with the NOAA Great Lakes Coastal Forecast System


Annual blooms from the worst 30-day period, MERIS 2002-2011; MODIS 2012

Log-scaled display

MODIS

WHO risk threshold

Modified from Stumpf et al., 2012 PLoSONE


Bloom severity over 11 years from satellite; sum of concentrations in western Lake Erie

CI of 1 ~ 1020 cells Microcystis


Cyanobacteria like warm water; strong growth > 20ºC; minimal growth < 15ºC

Paerl et al., 2011 (Science of the Total Environment)


Climatologic Temperatures in Lake Erie

Too cold

cool

Good growth

Excellent growth


Temperature gives season but not-interannual (avg temperature over western basin)

Years with small bloom

Years with large

bloom

Stumpf et al., 2012 PLoSONE

2011


Excessive phosphorus promotes cyano blooms

Downing et al., 2001; Can.J.Fish.Auat.Sci .


Use Maumee River Discharge to make seasonal predictions; largest tributary to Lake Erie.

Toledo

Dayton

USGS Ohio Fact sheet FS-035-96)


Understand blooms with nutrient load data

30+ year program measuring nutrients in Ohio rivers (Pete Richards, Dave Baker have led that effort)

National Center for Water Quality Research

http://www.heidelberg.edu/


Dissolved phosphorus, has a trend but much variability

Data from Pete Richards



Total phosphorus follows discharge; Spring (Mar-Jun).

Maumee River total phosphorus (m.tons)

Maumee River average discharge (m3/s)


Spring loads matter. Models predict CI (bloom severity) from spring discharge

& loads. See Stumpf et al., PLoSONE 2012

CI

Q model (based on Q-P correlation) Stumpf et al. 2012

Experimental SRP-Q model


2012 seasonal forecast

“…calls for a smaller bloom of the cyanobacteria HAB this summer, compared to recent severe blooms. Last year’s [2011] bloom, one of the largest in decades, covered … an area the size of Long Island Sound. This year’s [2012] mild bloom is expected to about one-tenth the size of last year’s.”

2012


Observed against model (and 2012 forecast) 2012 mild, but not as mild as model predicted

observed modeled

2012 forecast


2012: Unusual in several ways. Follows 2011 (which was nearly 3x more intense than the next worst bloom)

09 October : Data from MERIS (European Space Agency)


And other unusual events, cyano bloom in central basin in early July (!) disconnected

from western basin

10 July 2012 (bloom identified by Ohio EPA)


2012 had no ice

16 February, MODIS (from NASA Rapidfire)


This has happened before preceding both non-bloom years (2002 & 2005),

and a bloom year (1998).

(graph from Wang et al., 2012 J.Climate, Ice cover sq km)

bloom No-bloom 1998 was predicted by spring load model


Lots of “unusual climate” in 2012

2012 anomalous spring diatom bloom (water supply problems) Anomalous early July central basin bloom Follows biggest bloom ever (remarkably, that hasn’t happened previously in any years)

no ice

wet winter


2013: model uses Maumee River spring loads (2013 load falls between 2012 & 2011)

Data from National Center for Water Quality Research

Maumee River total phosphorus (m.tons)

Maumee River average discharge (m3/s)

average discharge based on USGS data (m3/s)

dissolved phosphorus load (m.tons)

total phosphorus load (m.tons)

2013 2013

2013



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

2013


2013 prediction for western Lake Erie “significant bloom” but 1/5 of 2011.

Definitely a significant bloom. Severity to be calculated this winter.

low medium high concentration

2013 on Sep 10 2011 for comparison


Climate patterns

We can estimate bloom severity. This allows for models of impacts under future

scenarios (assuming other things don’t change, like invasive species, etc.)

Spring load matters; caused by runoff and discharge.

Precip, snow melt, etc. influence nutrient runoff. Temperature allows for blooms, but does not drive

size (yet). Longer hot periods, longer blooms. >20 ºC: bloom appears; persists until <15 ºC.


Planning for climate change and variability will help the task of restoring and maintaining a Great Lake

Assistance from NASA Decision Support, Public Health NNH08ZDA001N

Photo from Gibraltar Island, Ohio Sea Grant

climate and harmful algal blooms in lake erie · 2013. 12. 20. · stumpf et al. 2012 ....

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