DISSOLVED OXYGEN IN LAKE ERIE: TEMPORAL, SPATIAL,AND WEATHER- INFLUENCED TRENDS IN THE CENTRAL BASIN, SANDUSKY SUBBASIN, AND WESTERN BASIN Presented at Ohio Academy of Sciences, April 2012

1. DISSOLVED OXYGEN IN LAKE ERIE:
TEMPORAL, SPATIAL,AND WEATHER-
INFLUENCED TRENDS IN THE CENTRAL BASIN,
SANDUSKY SUBBASIN, AND WESTERN BASIN
Maya Hughes
Maya C. Hughes1,
Maya Hughes
Phoenix Golnick1,2, and Douglas D. Kane1,2
1F.T.
Stone Laboratory, Put-In-Bay OH 43456 and
2Natural Science and Mathematics Division, Defiance
College, Defiance OH 43512

2. Outline
Overview
• Background of Hypoxia, Lake
Erie, and Stratification
• Purpose and Objectives
• Weather (2010 and 2011)
• Methods
• Results
• Why Important?

3. Hypoxia
• Less than 2.0 mg/L of dissolved oxygen
• World-wide problem
• Changed drastically in short period of
time
• Increasing problem in estuarine
water and shallow coasts
• Accelerated by human activities

4. Hypoxia:
Lake Erie
• Historically, problem in the central
basin
• Nutrient loading
• Summer stratification

5. Stratification

6. Stratification

7. Objectives
1. Compare relationships between temperature,
dissolved oxygen concentration, chlorophyll a
concentration, and depth.
2. Compare oxygen dynamics between western
basin, Sandusky subbasin, and the central basin
of Lake Erie.
3. Compare oxygen dynamics and stratification of
the three basins to observed rates in summer of
2010 in order to understand effects of weather.

8. Weather
Comparison of 2010 and 2011
March April May June

9. Weather
Comparison of 2010 and 2011

10. Weather
Comparison of 2010 and 2011
Number of storm events
(defined as three or more hours of continuous
wind speed greater than 7 m/s)
(Steinhart et al. 2005)

11. Methods Methods
• Sampled six sites in the Central basin,
Sandusky subbasin, and western basin
• Secchi Disk
• Multiparameter sonde (every 0.5 m) :
» Temperature (°C)
» Dissolved Oxygen (mg/L)
» Chlorophyll a (ug/L)

12. Sites
Six Sites

13. Results:
Hypoxia found earlier
this year- by a week

14. Results:
Hypoxia in Western Basin (Kelleys Island Deep)
and Sandusky Subbasin (Offshore)

15. Results:
Stratification
Central Basin Western Basin
Sandusky Subbasin

16. Results:
Comparing 2010 to 2011
Depth of hypolimnion (m)
Site (Month) 2010 2011
AP (June) 14.0 12.0
AP (July) 15.0 16.5
LO (June) 12.5 13.0
LO (July) 13.5 16.0
EAST (June) 10.0 14.0
EAST (July) 11.0 13.0
EAST (July) 12.0 13.0
SOFF (June) 10.0 13.5
SOFF (July) 10.0 13.0
SOFF (July) 11.0 12.5
KID (June) 12.0 13.0
KID (July) 12.0 11.0
KID (July) 12.0 13.0
Sites where start of hypolimnion
was deeper in 2011 than 2010

17. Results:
Hypolimnion Hypolimnion
thickness depth
• Significant • Significant
difference in difference in
hypolimnion hypolimnion
thickness depth
~0.73 m ~1.42 m

18. Results
• ANOVA:General Linear Model:
Mean DO (mg/L) versus basin,
year, month
P Compared to α = 0.05
Basin 0.000 < 0.050
Month 0.000 < 0.050
Year 0.553 > 0.050
Basin*Year 0.020 <0.050
Year*Month 0.517 >0.050
• Significant difference in dissolved
oxygen between basins and
months, but not between years

19. Conclusions
• Hypoxia was found earlier this year than last
summer (1 week)
• Significant difference in stratification
-Hypolimnion thinner
-Hypolimnion deeper
• Relationship between year and basin and
dissolved oxygen
• Central basin increased in dissolved
oxygen
• Sandusky Subbasin and western basin
decreased

20. Hypoxia:
Effect on Fish
• Effect habitat quality
• Influence metabolism, growth, reproduction,
and behavior
• Vertical and horizontal migration
• Increase spatial overlap- predation and
competition
(Vanderploeg et al. 2009, Brandt et al. 2011, Arend et al. 2011)
Round Goby Smallmouth Bass Yellow Perch Steelhead (Rainbow) Trout Walleye

21. Acknowledgments
Friends of Stone Laboratory
Dr. Jeff Reutter
Captains Russ Brohl and Matt Thomas
Thank You

22. Hypoxia:
Effect on Fish

23. Results: Interactions