Photo of a volunteer stocking fry in the Sawmill River. Credit: Draper White

Appendix D: History of Atlantic Salmon in the Connecticut River And Status of the Connecticut River Atlantic Salmon Restoration Program

The historic North American range of Atlantic salmon extended at least as far south as western Connecticut. The Connecticut River not only hosted one of North America's southern-most salmon runs but also its longest salmon run. Salmon once ascended the mainstem Connecticut River to its very headwaters (as far north as Beechers Falls, Vermont, nearly 400 miles upstream from the river mouth at Long Island Sound) and entered all major tributaries not blocked by natural barriers such as waterfalls. Precise numbers of fish that entered the various tributary systems are not available because the date of extirpation predated the development of fishery science and the ability to enumerate fish migrating upstream.

Recently, the size of, and even the presence of the historic Connecticut River Atlantic salmon run have been challenged in some archeological papers because of the failure of researchers to find salmon remains at archeological sites. Lack of evidence at such sites has fueled speculation that early colonists deliberately exaggerated stories of salmon abundance in the river. However, the assumptions about salmon habitat requirements used in the analysis of results have been questioned by salmon biologists who have refuted the theory that the salmon run was small or non-existent. Biologists speculate that failure to find salmon remains is due to the deterioration of such remains over time and/or inappropriate sampling techniques. Though some individuals, both colonial and contemporary, have likely been guilty of exaggerating the size of the salmon run, it is generally accepted that salmon existed in significant numbers though their numbers were never as great as those for Pacific salmon in the Northwest. Biologists have concluded that Atlantic salmon returned to the Connecticut River and its tributaries by the thousands when Europeans first arrived in this watershed. This is based on evidence from first person historical accounts, current understanding of salmon biology and habitat requirements, and present day salmon populations in Spanish rivers located at the same latitude as the mouth of the Connecticut River.

The native salmon population declined upon colonization by Europeans and development of water power sites throughout the basin. The major cause of the decline was the construction of dams that blocked salmon migration to upstream spawning habitat. Initially, dams for sawmills and gristmills were constructed across small tributaries. By the mid-1700s, major spawning tributaries such as the Salmon and Farmington Rivers were dammed, reducing the number of adult salmon returning from the sea. By the late 1700s, all of the tributaries in the lower portion of the watershed were devoid of salmon. All returning salmon had originated from and were destined for tributaries in the northern portion of the watershed where the human population was still very low. The first dam across the mainstem Connecticut River was constructed in 1798 near the present site of Turners Falls, Massachusetts. It blocked the access of salmon to the spawning habitat in the upper portion of the watershed and the species disappeared from the river within a few years.

An interagency state/federal program to restore salmon to the Connecticut River based on the stocking of fry hatched from eggs taken from Penobscot River salmon was initiated in the 1860s. Although the effort resulted in the return of hundreds of adult salmon for several years in the 1870s and 1880s, the program eventually failed due to uncontrolled harvest of fish in Connecticut waters, the failure to construct effective fish passage facilities at dams in Massachusetts, and the redirection of state efforts to other priorities.

Though interest in restoring salmon to the basin continued, no action was taken for decades. The condition of the river environment continued to deteriorate as a result of widespread pollution and dam construction. By the late 1960s, some tributary dams were removed or washed away and never re-built, and pollution abatement programs were initiated.

Long term cooperative restoration programs became feasible with the passage of the federal Anadromous Fisheries Conservation Act of 1966 (Public Law 89-304) which made funds available for interstate fish restoration programs. The combined effects of all these events set the stage for Atlantic salmon restoration.

The current Atlantic Salmon Restoration Program formally commenced in 1967 when the four basin states, USFWS, and NMFS signed a statement of intent to restore anadromous fish to the Connecticut River. Early stocking was comprised of two-year old smolts of Canadian origin reared in federal trout hatcheries that had recently been converted to salmon production. The first adult salmon return from these hatchery-smolt releases was documented in 1974. Between 1974 and 1977, twelve more salmon returned from the ocean. Penobscot River salmon smolts became available to the Program and were used to stock the river starting in 1976. As a result of this release, 90 adult salmon returned to the river in 1978. Since then, salmon, usually numbering in the hundreds, have returned to the river annually (see Table 4).

Early in the Program, emphasis was given to stocking smolts. The USFS joined the effort in 1979 because of the impact of that agency's land-based holdings on salmon habitat. Shortly thereafter, the USFWS built a large, modern salmon hatchery in Bethel, Vermont, and the CTDEP and MAFW converted trout hatcheries for salmon production. In 1983, hatchery-smolt production shifted from a two-year to a one-year rearing regime in an effort to increase the quantity and quality of smolts. Early experimental stockings of salmon fry into nursery habitat showed the potential for natural, instream rearing of high-quality smolts (referred to as "stream-reared" smolts) which are comparable to wild smolts. Evidence from the Farmington River indicated that stream-reared smolts produced from fry stocking yielded substantially greater adult return rates than hatchery-reared smolts. Production of stream-reared smolts was combined with smolts produced in hatcheries to increase total smolt emigration from the river. A major effort began in 1987 to stock as many fry as were available into appropriate habitat in the basin. Although numbers of fry stocked to date have been inadequate to fully stock all habitat, stream-reared smolts produced from those releases have contributed substantially to adult returns. Stocking totals are shown in Table 5.

Action to provide upstream fish passage on the river began prior to the salmon project when, in 1955, a fishlift was constructed at the dam in Holyoke, Massachusetts, to pass American shad. The Holyoke facility was expanded in 1975 and 1976 when a second lift, a flume, and a trap were built. Other fishways were built between 1974 and 1987 at the next four upstream dams on the mainstem river, Leesville Dam on the Salmon River, Rainbow Dam on the Farmington River, and later at the DSI Dam on the Westfield River. These fishways allowed returning salmon access to a larger portion of the basin targeted for restoration. Although most salmon are currently captured at the lowermost dams and retained for broodstock, fishways constructed at the upstream dams pass released salmon, and American shad and other species (which migrate upstream by the thousands). Fish passage at dams above Vernon Dam have been built specifically for salmon. A listing of fish passage requirements for Atlantic salmon in the Connecticut River basin is provided in Appendix G.

Downstream passage facilities, designed to safely guide smolts past hydroelectric sites, were not included in fishway construction at the seven originally targeted dams nor were they mandated at most of the other dams in the watershed. As the number of fry stocked in the basin increased during the 1980s, concern grew for the deleterious effect of hydroelectric turbines on outmigrating smolts. Responding to that concern, releases of most hatchery-reared smolts were moved downstream of the lower-most dam. Stream-reared smolts, however, were still forced to pass through turbines at numerous hydroelectric generating stations as they emigrated downstream to the ocean. Efforts to provide downstream fish passage on both mainstem and tributary projects were initiated in the 1980s. In 1990, memoranda of agreement were signed with two major utility companies that operate six mainstem hydroelectric facilities. These agreements established timeframes for downstream passage studies and construction. Efforts to provide effective fish passage at these projects and throughout the basin are ongoing.

Notes:

Data designated with a dash indicate that trapping facilities and/or upstream passage were not available or operational during that year.

* 1996 - Wilder operated but not monitored. CRASC closed the mainstem to fishing in 1986, all subsequent documented angling was illegal.

1986 5% sea runs released upstream; 1987 to present 10% sea runs released; 1996 Turner's Falls count is incomplete.

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