Lecture by Akiko Busch. Whether it’s pulling up water chestnuts in the Hudson River, measuring beds of submerged aquatic vegetation, or searching out vernal pools—citizens can play a vital role in scientific research. Cary Institute auditorium, 2801 Sharon Tpk., Millbrook, N.Y. Free. Seating is first come first served. Doors open at 6:30 p.m. www.caryinstitute.org.