Blog post by CRWA's Aquatic Scientist
The herring are back! It's that time of year; alewife and bluback herring have once again returned to the Charles River to spawn. Estimates of the river herring population on the Charles run upwards of 300,000 fish, making our herring run one of the largest in Massachusetts. Based on historic observations, we expect that the majority of herring, approximately 80% of the run, will pass through the Watertown Dam within the next week. The fish ladder the herring will use to swim against the current over the dam is on the southern bank of the river, but you can easily see the fish waiting in calmer waters under trees just below the dam from the Charles River Greenway on the north bank of the river. If you have polarized sunglasses, you can get an even better view! If you are unable to walk or bike to the Watertown Dam, limited parking is available at the DCR parking lot off of Pleasant Street on the north side of the river and on the side of California Street on the south side of the River. Fish that pass over the Watertown Dam continue their journey upstream in search of streams that feed into the Charles River, such as Beaver Brook and Stony Brook in Waltham and the newly-restored Fuller Brook, Rosemary Brook, and Waban Brook in Wellesley. Some herring do not continue up to the Watertown Dam after passing through the locks at Boston Harbor and instead swim up the Muddy River in Boston. If you see herring or other fish in the Charles River or one of its tributary streams, send us your photos on Facebook or Twitter!