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[Descriptions
| Habitat
| Surveys
| Safe
to Eat? | Natural
Community | Fish
Stocking | Fishing
in the Assabet Watershed]
Under the surface of the Assabet River and its
tributary streams is a hidden world inhabited by fish and
other aquatic creatures including turtles, freshwater mussels,
insects and microscopic animals called zooplankton. StreamWatch
focuses on fish because they are relatively long-lived, sensitive
to a wide range of environmental stresses, and are easy to
identify. In many ways, fish are the most visible and well-understood
barometers of stream and river health.
Are the Assabet River tributary streams healthy
habitat for fish?
To answer this question we need to understand the basic needs
and life cycle of the fish that live, or should live, in the
streams. These habitat needs, in terms of water quality, flow,
and physical habitat can then be compared with measured conditions
in the streams.
Since different fish have distinctly different
needs, we will narrow the range of ideal conditions to compare
with by choosing an “indicator” fish for each stream.
If a stream can support an indicator species population, other
less sensitive species can thrive in it too. For most of our
project streams, we will use Eastern Brook Trout as our “canary
in a goldmine”.
An indicator fish:
- Must be found (or have been found historically) in the
stream
- Must be a river fish - one that needs flowing water during
some (fluvial dependent) or all (fluvial specialist) of
its lifespan
- Should be a native fish
- And should be sensitive to pollution.
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| Division of Fisheries and Wildlife
conducts a fish survey along the Assabet River in Concord,
May 2001. |
Another way of assessing whether the streams
are healthy for fish is to look at the fish community. How
does the existing community (species and numbers) compare
to the community one would expect to find in unpolluted, free-flowing
streams in southern New England. For the tributary streams,
we can compare historic fish surveys with the findings of
surveys done in 2001.
It is also useful to understand the needs of
the alewife and shad that once lived here. Alewife and shad
are anadromous fish, migratory fish which hatch in fresh water,
make their way to the sea to grow, then return as adults to
fresh water to spawn. Downstream dams on the Concord River
currently block their return to the Assabet watershed. The
Mass
Division of Fisheries and Wildlife, the Mass
Division of Marine Fisheries, and the U.S. Fish and Wildlife
Service are currently cooperating in efforts to restore anadromous
fish to the greater Merrimack River watershed - including
the Concord River.
Photo credits:
All of the fish photos in this section are used
with permission from their owners. Photo credits appear at
the bottom of each photo. If you are interested in using any
of the photos from this site please email
OAR for contact information for each photographer/owner.
Fish References:
Bain, Mark B. "Macrohabitat Classification of
Freshwater Fishes, Research Notes and Instructions New
York Cooperative Fish and Wildlife Reseach Unit", Department
of Natural Resources, Cornell University, Ithaca, New York.
Fall 1989.
Becker, B.C. Fishes of Wisconsin. University of Wisconson Press, Madison, WI. 1983.
Burr, B.M., and M.C. Warren, Jr. A Distribution Atlas of Kentucky. Kenturcky Natural Preserves Commissioin, Scientific and Technical Series 4, Frankfort, KY. 1986.
Hartel, K.E., D.B. Halliwell,
and A.E. Launer. "Inland Fishes of Massachusetts" Massachusetts
Audubon Society, Lincoln, Massachusetts. 2002. (Download order
form in pdf format). (Karsten Hartel can be contaced at
Harvard's Department
of OEB.)
Kologe, Brian R. "AMC Guide to Freshwater Fishing in New England". Appalachian Mountain Club, Boston, Massachusetts. 1991.
Massachusetts Wildlife, No. 2, 2000, Special Fishing Issue.
Robison, H.W., and T.M. Buchanan. Fishes of Arkansas. University of Arkansas, Fayetteville, AK. 1984.
Rohde, Fred C., Rudolf G. Arndt, David G. Linquist, and James F. Parnell. "Freshwater Fishes of the Carolinas, Virginia, Maryland & Delaware". The Unversity of North Carolina Press, Chapel Hill. 1994.
Scott, W.B., and E.J. Crossman. Freshwater Fishes of Canada. Fisheries Research Board of Canada Bulletin 184. 1973.
Werner, Robert G. "Freshwater Fishes of New York State". Syracuse University Press, Syracuse, New York. 1980.
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