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Lake Erie Commission. OHIO SEA GRANT AND STONE LABORATORY. Speculating on the Impact of a Very Cold Winter. Dr. Jeffrey M. Reutter Director, Ohio Sea Grant College Program 26 March 2014. OHIO SEA GRANT AND STONE LABORATORY.
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Lake Erie Commission OHIO SEA GRANT AND STONE LABORATORY Speculating on the Impact of a Very Cold Winter Dr. Jeffrey M. Reutter Director, Ohio Sea Grant College Program 26 March 2014
OHIO SEA GRANT AND STONE LABORATORY The winter before the 2011 bloom was also very cold. Does that mean we might see another bad bloom this year? • Runoff and P loading from 1 March to 30 June is the primary driver for HABs. • The 2011 bloom was driven by the wettest spring in the past 50 years.
OHIO SEA GRANT AND STONE LABORATORY Does the long winter and cooler lake temperatures now mean the lake will be slower to warm over the summer, perhaps delaying the onset of a bloom? • It is reasonable to think that this might happen and we will be watching lake temperatures closely. However, a very warm May can totally alter the temperature.
OHIO SEA GRANT AND STONE LABORATORY Do cooler lake temperatures mean cooler breezes off the lake over the summer? • Northerly winds will be cooler anytime lake temperature is lower. If the lake is cooler this summer, northerly winds will also be cooler. But no guarantee the lake will be cooler this summer.
OHIO SEA GRANT AND STONE LABORATORY Do colder lake temperatures mean more deposition within the lake, pulling phosphorus-laden sediment with it, maybe less available phosphorus in the water column for algal growth? • Typically Lake Erie gets very clear when we have ice cover and even the finer particles settle out. However, resuspension during storms is incredibly rapid. I expect the lake to be very yellowish brown (diatoms) with the first storm.
OHIO SEA GRANT AND STONE LABORATORY Do diatoms aggregate under the ice, and does that biomass contribute to hypoxic conditions in the central basin? • Yes to both questions. See Twine Line, Summer-Fall 2012 issue about a project we funded with George Bullerjahn and Mike McKay (BGSU) working off Coast Guard ice breakers. • Excessive nutrient loads in the fall and winter probably drive these blooms.
OHIO SEA GRANT AND STONE LABORATORY How will this winter impact lake level? • Ice cover reduces evaporation. Typically evaporation is greatest during the winter when humidity is often very low. Lake levels are likely to be in the near-normal range this year. However, this can change quickly if our region has a lot of rainfall this spring or a drought.