All invited to learn about and help collect macroinvertebrates—including insect larvae and crayfish—from Huron River tributaries to measure the river’s health. Kids welcome if accompanied by an adult. Two start times. Rain or shine. 9 & 10:30 a.m., various places as assigned. Free. Preregistration required at hrwc.org/volunteer/roundup. (734) 769–5123, [email protected].