pdf WQ10 Water Temperature Decline in the Les Cheneaux Islands During a Period of Unprecedented Water Level Rise

Authors: R.A. Smith

Author Affiliation: LCWC

Journal: LCWC Report; February 24, 2021


The Les Cheneaux Watershed Council has monitored water quality variables within the Les Cheneaux Islands (LCI) since 2001, a project sponsored by the Les Cheneaux Islands Association. A period from 2013 through 2020 was different from previous years in that the Lake Huron rise (LHr) continued every year. Resulting LHr of 171 cm ( 67.4 in) occurred from a record low level in January 2013 to a record high level during the summer months of 2020. Water temperature profiles during the sampling season from May through Sep decreased 5°C ( 9.5°F) during the LHr. This study examines the relationship between L Huron level and LCI temperatures during those eight years. It is possible that the simple incursion of cooler LH water into the LCI channels could have could have contributed to lower seasonal temperatures. If that hypothesis is true, then such volumes of cooler, low-nutrient LH water could affect food webs within the islands which could have long lasting environmental effects on aquatic systems, especially the aquatic plant community. A follow-up examination of the phosphorus and plankton variation during the same period will follow this study.