|Blueback herring spawn in the Charles
The Charles River supports a diverse community of fish, including
over 25 species of resident freshwater fish and a host of anadromous
species. Anadromous fish are born in freshwater, spend most
of their lives in the ocean and return to freshwater to reproduce.
They depend on the river for spawning habitats during
their dramatic spring runs.
Collectively known as river herring, alewife and blueback
herring are two of the most well-known anadromous fish in the
In fact, the Charles River supports one of the largest blueback
herring runs in the Commonwealth. River herring can typically
be observed spawning in the river from mid-May to mid-June. Rainbow
smelt, however, are the first to arrive each spring, when spawning
begins in mid-March below the Watertown Dam. American
shad and white perch also use the river for spawning habitat,
whereas striped bass enter the Charles to feed.
species, catadromous fish are born in the ocean and travel
to freshwater habitats to feed and mature. The
American eel is a prime example of this, and each spring tiny
juveniles or “glass eels” can be found moving
up the Charles.