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Posted January 11, 2000

Atlantic Salmon, Restoration, Rehabilitation, and Federal Protection

By John Moring, Professor of Zoology

Atlantic salmon were abundant in New England when the first European settlers came to North America, but harvesting, dams and pollution devastated most river specific populations by the late-1800s. By the 1980s, restoration efforts were marginally successful and led to hope for full recovery, but since then, populations in New England and eastern Canada have declined. A federal Endangered Species Listing would affect potential threats to salmon stemming from land use activities and water management. The listing would not affect threats related to predation and other ecological factors. Additional federal money is likely to be made available for restoration efforts.

The Past . . .

Atlantic salmon were abundant in New England when the first European colonists arrived in the 17th century. Although opinions differ as to whether salmon were present for centuries prior to that time-or whether they were even utilized by Native Americans-they certainly have been present in New England for the past 350 years. Humans began to exploit the populations from the mid 1600s. By the mid-1800s, some runs of Atlantic salmon in southern New England were already devastated, while the other runs were showing severe declines brought about by impassable dams, pollution, and commercial fishing.

The Kennebec and other salmon runs in southern and central Maine suffered the same fate in the 19th century. The last major run in the United States was in the Penobscot and disappeared in the early part of the 20th century. Only smaller populations, on Maine streams with few or no dams and minimal pollution, continued to support fragile populations: the Ducktrap, Dennys, Sheepscot, Pleasant, Machias, East Machias, and the Narraguagus rivers, and probably Cove Brook, a tributary to the lower Penobscot River.

History of Restoration . . .

Technically, restoration of Atlantic salmon runs in Maine began with the creation of the Maine Atlantic Sea-Run Salmon Commission in 1947. But the causes of the decline and disappearance of Atlantic salmon in Maine continued to exist (especially dams and pollution). It was not until the 1960s, when several water quality improvement laws were enacted and fish passage facilities were constructed at dams, that restoration efforts started to show some progress. The Penobscot River was designated the first Model Restoration River in the United States and it was later followed by similar programs on the Connecticut and Merrimack rivers and elsewhere. Multi-agency programs were established for Maine, and a Technical Advisory Committee, composed of federal, state, university, and tribal representatives, continues to provide guidance to fish culture, research, and management decisions.

Optimism and Pessimism . . .

Initial efforts to restore the depleted Atlantic salmon populations on the Penobscot River showed steady progress, largely through stocking and the successful return of adult fish. Salmon cultural practices improved, as did knowledge of fish nutrition, disease control, size and timing of stocking, and density of stocking. In 1986, over 4,500 adult salmon returned to the Penobscot River. Runs on the eight smaller streams, where populations had continued to survive, continued at low levels, in some cases supplemented by stocked smolts, fry, or parr that did not come from the downeast rivers. But accurate records of the sizes of spawning populations always were unknown, or were based on angler rod count trends, because most of these smaller rivers lacked trapping and counting facilities.

By the late 1980s, biologists were somewhat optimistic that the Atlantic salmon population of the Penobscot River could be restored. A predictive model estimated that runs would steadily increase and stocking could be terminated on the river early into the 21st century, but that level of return has never been achieved.

Despite the optimism of 15 years ago, runs on the Penobscot River have declined to a little over 1,000 adult fish in most years and numbers in the Downeast rivers have declined as well. Many are now documented by counting weirs.

What Is Happening? . . .

Despite better quality fish being stocked into Maine rivers, at more appropriate densities and in more suitable habitat, and despite the use of river-specific stocks, the numbers of returning salmon have continued to decline. But, the situation is not unique to just Maine. Many salmon runs in eastern Canada have suffered similar declines, and restoration programs on the Connecticut and Merrimack rivers have resulted in only a few returning fish, despite the infusion of tens of millions of dollars. Even runs of American shad, blueback herring (river herring), and alewives in southern New England have all experienced declines.

This has led many to believe that some factor in the ocean environment is affecting survival of salmon before the fish can return as adults. There is some evidence that shifting oceanic temperatures may be affecting open water food supplies for salmon. Others point to the genetic components of the fishes themselves, a subject that is discussed in another white paper summary. Most of the fish now returning to the Penobscot and other larger rivers of Maine were born in the hatchery, or had relatives who were born there, originally created from non-native sources. Others point to additional sources of mortality, such as predators (e.g., Federally-protected double-crested cormorants, or "shags," near dams, Federally-protected seals in estuaries, and known fish predators, such as smallmouth bass and chain pickerel in rivers), use of herbicides on blueberry fields, water diversion, land use alterations, and genetic influences of escapees from offshore aquaculture cages. There is valid evidence that each of these factors are contributing, to some degree, to the decline of salmon.

What Would Protective Listing Do? . . .

Listing Atlantic salmon with the Endangered Species Act would not immediately result in rehabilitation of runs on the eight target rivers or restoration of Maine's other salmon runs. No one can be certain what restrictions might be imposed on the state's agriculture, forest products, or aquaculture industries, or on urban development or road construction. Federal listing will do little to affect some of the causes of salmon mortality, such as bird, seal, and fish predation and oceanic temperatures. But federal listing will result in several immediate actions. Salmon in the eight target rivers will receive added Federal protections which would shift much of the overall management guidance to the federal government, with operational management by state agencies and private organizations.

Recreational fishing would not be allowed, although this was recently banned by the Maine Atlantic Salmon Commission for the first time in history. Certain management, research, and monitoring activities would be restricted or even banned because of even possible impacts on a threatened species. There likely would be additional federal dollars available to supplement the very limited state and private funding currently being shifted from non-salmon fisheries work, and this would be a welcome addition to rehabilitation efforts. Whereas the efforts of the existing state plan have sought to rehabilitate salmon runs by working jointly with industries and citizen groups, so that salmon and industries can continue to co-exist, an Endangered Species Recovery Plan would focus more on the salmon and attempt to eliminate or minimize all threats to its existence.

Key words: Restoration, declines, Atlantic salmon

For further information, please feel free to contact:

John Moring, Professor of Biological Sciences, 207-581-2582, jmoring@maine.edu

Dr. John Moring is a research fish biologist with the U.S. Geological Survey. He studies aspects of fish ecology and fisheries management for freshwater, marine, anadromous, and catadromous fishes. His current research is funded by the National Park Service and the Maine departments of Inland Fisheries and Wildlife and Marine Resources.

If you would like to receive addition copies of this white paper or any other papers in the series, please contact:

Judith Round, College of Natural Sciences, Forestry, and Agriculture, University of Maine, 5782 Winslow Hall, Orono, Maine 04469-5782

Telephone: (207) 581-3229; E-Mail: judy.round@umit.maine.edu

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