Matfield River below Rt. 18 East Bridgewater

Historic spawning grounds of American Shad

 

The American Shad was once one of the most abundant species in our Great River. Like its relative the alewife it came up from the sea in great numbers to spawn. The shad is considerably larger than the alewife and can be as large as ten pounds, however they more typically run between two and eight pounds. Unlike the alewife the shad spawns in both the main stem and the larger tributaries of  rivers as opposed to ponds. They spawn at night on the surface in areas of moderate current. After the eggs hatch the juveniles remain in the river until fall, when they like the alewives move back down to the sea to complete their life cycles.

There are many references that hint at the shads former abundance in our Great River. Various history books tell us that shad were an important food source for the Wampanoags, they ate both the whole fish and especially relished its roe (eggs). This passage from the History of East Bridgewater by William Allen is also of some interest he writes "Shad seemed to prefer the Matfield River, and a shad weir was once located on that stream, not far from the bridge of the Bridgewater Branch Railroad". David Belding in his Fisheries Report of 1920 also refers to shad spawning in the Matfield and a weir that was built there to catch them. There were also several colonial laws passed for the protection of shad throughout the river. The following were found in volumes of the Acts and Resolves of the Massachusetts General Court (in the future we will publish these full documents in the history part of the website). The first is from 1791, its heading reads as follows.

  " An act to prevent the destruction of Fish called Shad and Alewives, in Ten and Three-Miles-Rivers, in the county of Bristol. There was another similar act passed for Bridgewater in 1824  and for Middleboro and the Nemasket in 1855 along with several others.

More recently, in 1967 through 1970 the Massachusetts Division of Marine Fisheries surveyed the Taunton Great River for shad restoration. The following is the report on the results of that survey.

 

The Taunton River drainage system is one of the largest watersheds in the Commonwealth. With its large, unimpounded main stem, many tributaries and  numerous headwater ponds, it offers potential for many species of anadromous fish. The river once supported an extremely large alewife fishery and shad were present in good numbers. While alewives are still numerous, the production is far below the system's potential and shad have virtually disappeared.

The cause of the decline in anadromous fish populations were pollution and obstructions on tributaries. Pollutants in the form of industrial and domestic wastes are present in great amounts in the main river and many of its tributaries.

Of particular concern are wastes entering the river from industries and sewerage discharges in the city of Taunton. These have created an area of low dissolved oxygen and high ammonia-nitrogen content downstream from the city. Minimum dissolved oxygen of 0.3 mg/l and maximum ammonia-nitrogen of 1.22 mg/l were recorded during the latter part of July, 1970. Ammonia has a high oxygen demand and increases the oxygen requirement of fish. The majority of alewives spawning in the Taunton River system must pass through this area to reach spawning grounds. Concentrations of dead juvenile alewives have been observed within this area during the spring and its effect on adult alewives is not known.

The Massachusetts Water Resources Commission has given this section of the river an SB classification. Under this classification water quality must be improved to the point that dissolved oxygen is not less than 5.0 mg/l and ammonia-nitrogen does not exceed an average of  0.2 mg/l during any month. It is anticipated that water quality will be improved to eventually meet these standards and will no longer be a detriment to anadromous fishes.

Bottom sampling was conducted on the Taunton River in order to determine potential shad spawning area. The sampling area extended from the Berkley Bridge, Dighton to the Jenkins Leatherboard Company dam in Bridgewater, a total of 28 river miles. Berkley Bridge was selected as the lowermost station because it marks the limit of salt water intrusion during the spring. The upper limit of the sampling area is at the dam blocking further upstream migration.

Suitable spawning habitat was interpreted as all areas of the river with bottom types other than mud or silt. The section of the Taunton River sampled, contained 1,154,481 square yards of potential spawning area with a minimum potential adult population of 26,553 shad.

The Division is now trying to restore shad to the Taunton River system. An egg stocking program was initiated in 1969 and will continue for at least four years. Eggs are being stripped and fertilized from Connecticut River shad and are being planted in the Nemasket River, a major tributary to the Taunton River.


Since the time of this report the egg stocking program and a subsequent adult shad stocking program in the 1980s have failed to produce any appreciable results. Due to budget cuts within the anadromous fish department no further investigations have been done since the 1980's. Further budget cuts in the past year within this department have left it bare boned, further limiting their ability to perform important research into this matter.

Although we are not and do not claim to be experts in these fields we think our observations in regards to the lack of shad in the system provide a good starting point to address this situation.

As we said previously the river itself has not changed much in its physical characteristics since shad were abundant. The factors that led to the shads decline were water quality and access to spawning habitat (dams). Today there are no dams to prevent them from reaching much of their historic range. In fact since the above survey was done the Jenkins Leatherboard dam has breached opening up far more habitat than when the 1967 survey was done. That leads us to the question, what about water quality?

There is no doubt that the water quality today is better than when the above survey was done in 1967, but how much better is it? In that survey they say in regards to water quality " Under this classification water quality must be improved to the point that dissolved oxygen is not less than 5.0 mg/l and ammonia nitrogen does not exceed an average of 0.2 mg/l during any month. It is anticipated that water quality will be improved to eventually meet these standards and will no longer be a detriment to anadromous fishes."

Unfortunately today, thirty years after this report was published there are still dissolved oxygen problems in the river. Although the river no longer takes in industrial waste it does take in about 23 million gallons per day of effluent from municipal treatment plants in the upper river alone. Twenty one million gallons per day of this effluent from the city of Brockton is in "significant violation" of the US Clean Water Act (according to the chief engineer from Camp Dresser & Mckee).  Both the Taunton River Watershed Alliance and the USGS sampling show DO levels falling below the minimum standard of 5.0 mg/l during the summer, in the main stem of the river and in Matfield River (see under public comments to DEP). Nitrogen pollution in these rivers is also still a serious problem.

Whether or not water quality is the limiting factor we do not know for sure. However we do know that shad were once abundant here, today they are not. The primary difference between the river now as opposed to when shad were abundant is the quality of the water.

If nothing else these are indications that it is about time for a comprehensive effort by the regulating agencies to determine what impact water quality has on our remnant populations of shad and other anadromous fish.

 

Follow this link for more info on our good friend the American Shad - Shad info

Connecticut River - American Shad info

Current coast wide status of - American Shad

More info on the restoration of - American Shad

 

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