The project team (MDEQ, DLZ) currently deploy 4 Hydrolab DS5X multiparameter sondes into the waters of Thunder Bay, Lake Huron, near Alpena, Michigan. What makes our deployment so unusual and difficult is that the sondes need to be deployed underwater from November to April – in Michigan this means they are typically under ice cover for several months!
The sondes are deployed using a NOAA dive team that inserts them into monitoring wells that were built as part of newly constructed reef habitat for fish such as lake trout and whitefish. Since both fish spawn in late fall and the fry emerge often under ice cover in early spring, the sondes are helping us to monitor oxygen availability and water temperatures in the reef where the eggs and fry are present. Because they cannot be retrieved under the ice we need an instrument that can withstand the ambient conditions and be able to collect data for over a 5 month period. We are preparing for our 5th year of deployment this winter!