Zebra Mussel Larvae Confirmed in Rainy Lake
Disappointing news. Zebra mussel larvae have been confirmed in Rainy Lake by the Minnesota Department of Natural Resources (MNDNR). The larvae were found in four of five water samples taken in July 2021, suggesting that there is a reproducing population in the lake according to MNDNR. This follows on an unconfirmed report of larvae in 2020 by a member of the public. Locations of adult reproductive colonies have not yet been located or confirmed. Rainy Lake straddles the Ontario-Minnesota border and flows downstream via the Rainy River to Lake of the Woods.
This follows equally concerning confirmations by MN DNR in 2019 and 2020 of zebra mussel larvae at several sites in the southern portion of Lake of the Woods.
Algae Bloom has arrived on Lake of the Woods
The seasonal algae bloom on Lake of the Woods is underway and has progressed up into the north end of the lake, as shown in the satellite image and associated derived chlorophyll-a data for August 31.
For much of the summer, it seemed like a “light year” for algae blooms, but blooms began to develop in mid-to late August. The low blooms in much of the mid-summer may perhaps be due to the low water and low flows from the nutrient-rich southern basin of Lake of the Woods, or perhaps lower light conditions due to the intense smoke that blanketed the lake throughout July and into the first week of August. The smoke conditions also likely limited the days for which the satellite tools could generate good chlorophyll-a estimates. The satellite tools, developed by Dr. Caren Binding at Environment and Climate Change Canada, hold much promise for long-term monitoring of trends in algae bloom intensity and severity.