Volunteers are needed to help with the annual herring-run cleanup on April 6, starting at 8 a.m. Participants will meet at Herring Run Park in Jackson Square. The annual event includes removing brush and debris from the channel, making it easier for the herring to get back to their spawning grounds upstream at Whitman’s Pond. Thousands of herring typically pass through Jackson Square starting in mid-April, according to the state Division of Marine Fisheries. More information is available by calling herring run warden George Loring at 781- 749-0189.