A multidisciplinary committee will review the available scientific information on the status of Atlantic salmon populations in Maine and, where relevant, in adjacent areas. The committee will assess causes of the declines of their populations and the current threats to the continued survival of salmon, will evaluate the evidence on the population structure of those salmon, and will evaluate options for improving the survival of salmon. In assessing information, the committee will identify significant knowledge gaps and suggest additional research that would be important to the conservation and recovery of salmon populations.
Factors to be evaluated include the nature and distinctness of salmon populations in Maine rivers and surrounding areas; the interactions between aquaculture, hatchery, and wild populations; terrestrial and marine environmental factors affecting salmon populations; the effects on salmon of changes in the hydrology of Maine streams; and the effects on salmon of subsistence, recreational, and commercial fishing in freshwater and ocean areas in and around Maine.
A brief interim report will be produced within 9 months after formation of the committee. The interim report will address the genetic makeup of wild salmon populations in Maine and its possible relationship to recovery activities. A final report at the end of the study will describe and synthesize the information available on the biology of Atlantic salmon, the causes of their population declines, and the threats to their continued survival. It will evaluate and describe options for enhancing their continued survival and recovery and will provide some approximate estimates of the relative costs of the various options.
Naturally reproducing populations of Atlantic salmon occur in rivers and streams from southwestern Maine to northwestern Europe. Historically, they were found in the Hudson River in New York and north and east to the Canadian border, but today they are found only in Maine, from the Sheepscot River to the Canadian border. The populations have declined drastically, from perhaps half a million adults returning to all U.S. rivers each year in the early 1800s to a minimum estimate of 1,050 in 2001. Most U.S. Atlantic salmon are in Maine rivers, and 780 (90%) of those returned to only one river, the Penobscot, in 2002.
Salmon spawn in freshwater, where the young hatch and grow for 1–3 years before migrating to sea. At sea, they grow faster in the rich marine environment and then return as adults to the rivers where they hatched (called natal streams) to spawn—a life history called anadromy. Most adult salmon die after spawning, but some return to the ocean, and some of those fish return to spawn again. Some males mature early and survive spawning more often than adults do.