Fish & Aquatic Life
Our greatest reason to restore the Ipswich River often lies below its surface: the fish, insects, turtles, salamanders, otters, and myriad of other wildlife that depend on the River to provide them homes, food, and life. Unfortunately, the trends we are seeing in the health of many of these populations, particularly fish and aquatic insects, indicate that the low flows, low dissolved oxygen levels, and development of the watershed of the Ipswich River are having a devastating effect.
Click here to see pictures of sunfish in the Ipswich River

In the distant past, native Americans of the Agawam tribe fished along the Ipswich River, as is evidenced by mounds of shell fragments (known as middens), bits of pottery and other artifacts which have been found along the river bank. Captain John Smith referred to this region as the “land of promise” because of its abundant fisheries and mature forests. In early colonial days, the spring runs of herring, shad and other anadromous fishes were amazingly bountiful. The harvest of alewife (river herring) as far upstream as Wilmington and North Reading was an important part of the local economy in those early days. Wenham Lake, now a public water supply reservoir, was the most important alewife nursery in the region.
Today, the Ipswich River is heavily impacted by water withdrawals and dams, which have changed its ecology drastically, especially impacting the native fishery. Species which require flow are at a disadvantage, and the river is dominated by pond/warm water species. There are river restoration efforts underway. Reducing water withdrawals is the first line of defense, and we invite fishermen to add their voice to those working to save some water for the fish!
Consider these trends:
- At least 67 percent of the fish in the Ipswich River should be species that require flowing waters – that is, river fish. A recent study conducted by the Massachusetts Department of Fisheries and Wildlife and the United States Geological Survey found that instead, over 90 percent of the fish in the Ipswich River are pond species that can survive without flowing water and in stagnant conditions.
- Since monitoring began in 1999, the most river herring observed in the Ipswich River was 96 fish in 2005. By contrast, at the Ipswich River’s neighbor, the Parker River, almost 8,000 herring migrated up the river that same year. Click here to see results from the past ten years of herring counts.
- Out of 8 sites monitored since 1997, macroinvertebrate monitoring results have shown 6 of those sites to have moderate or severe impairment every year they were monitored.
- Photographs and anecdotal evidence of fish kills in 1995, 1997, 1999, and 2002 show that average fish size and age is dropping radically, indicating that the frequency of massive kills may be preventing most fish from reaching reproductive age.
- At least 14 species of fish once lived or spawned in the freshwater portion of the Ipswich River, but they have not been found in the River or its tributaries during recent surveys. Among those species are johnny darters, white perch, rainbow smelt, and Atlantic salmon.
From the State of the River 2003 Report (pdf)
Ipswich River Nature
Naturalist Jim MacDougall is creating a list of the large creatures that live within the confines of the Ipswich River Watershed. Please email Jim if you have additions, suggestions, or corrections!
Ipswich Fish Consumption Advisory
The Massachusetts Department of Public Health has issued an advisory that mercury in fish caught in the Ipswich River may pose a public health threat. Detected mercury levels fell below the Food and Drug Administration Action Level of 1.0 mg/kg, but within a level that may pose a concern to certain individuals. MDPH recommends that children under 12, pregnant women, nursing mothers, and women who may become pregnant refrain from consuming any fish from the Ipswich River. All others should limit consumption to two meals per month.
More information about fish consumption advisories in your area is available from the Massachusetts Department of Health and Human Services.
For more information:
Press Releases and Recent News Features
- “Fishermen concerned over loss of river herring in local waters” Newburyport Current, March 27, 2008
- “Herring: A small fish that is a big deal” Gulf of Maine Times, Winter/Spring 2008
- “Migration barriers threaten eel population: Fewer seen in the Northeast” Boston Globe, June 2007
- “For Maine’s alewives, the possibilities are as large as the threats” The Working Waterfront, May 2007
- “Fish populations decline in region: Cause of drop in river survey is still unclear” Boston Globe, July 8, 2004
More Information
- University of Massachusetts Adopt-A-Herring page contains information on the herring study being conducted on the Ipswich River
- Division of Marine Fisheries page on Anadromous Fisheries includes information on herring and fish ladders
To learn more about specific species of fish in the Ipswich River Watershed, check out the Division of Marine Fisheries fact sheet series.
- TR-18 Reback, K.E., P.D. Brady, K.D. McLauglin, and C.G. Milliken. 2004. A survey of anadromous fish passage in coastal Massachusetts: Part 4. Boston and North Coastal.
- TR-30 Chase, B. C. 2006. Rainbow smelt (Osmerus mordax) spawning habitat on the Gulf of Maine coast of Massachusetts.
For more information on Ipswich River fisheries, please visit Fisheries Restoration Resources.








