Citizen scientists are invited to be volunteer herring counters for the North and South Rivers Watershed Association this spring. The count, which will run seven days a week between April 1 and May 31, will take place six to nine times daily at four locations, including Third Herring Brook in Hanover and Norwell. Volunteers count for 10 minutes at a stretch, preferably several times per week. Fishery experts benefit from the field observations of counters, which help them gauge herring health. Other sites for the herring count include South River at Veteran’s Memorial Park fish ladder in Marshfield, Herring Brook at Upper Mill Pond fish ladder in Pembroke, and First Herring Brook at the Old Oaken Bucket fish ladder in Scituate. To get involved, visit www.nsrwa.org.