land and the Faroe Islands. A commercial fishing industry was established, taking salmon using drift nets. After an initial series of record annual catches, the numbers crashed; between 1979 and 1990, catches fell from four million to 700,000.
Overfishing at sea is generally considered the primary negative factor, though marine exploitation rates estimated for various Newfoundland stocks for the period 1984–1991 averaged 45% on small (<63 cm) salmon and 74.2% on large salmon (>63 cm); closure of the Newfoundland commercial salmon fishery beginning in 1992 has not resulted in general increases in salmon populations through the present.
Beginning around 1990, the rates of Atlantic salmon mortality at sea more than doubled. In the western Atlantic, fewer than 100,000 of the important multiple sea-winter salmon were returning. Rivers of the coast of Maine, plus southern New Brunswick and much of mainland Nova Scotia saw runs drop precipitously, and even disappear. In the mid-1990s, the Atlantic Salmon Federation in cooperation with partners developed sonic tracking technology, and by 2008, the salmon had been tracked from rivers such as the Restigouche and the Miramichi as far along their migration routes as the Strait of Belle Isle, between Labrador and Newfoundland, and halfway to feeding grounds off Greenland. The problems at sea remain, leading to a concerted international effort, called SALSEA, to find out more about the mortality at sea. It is organized by the North Atlantic Salmon Conservation Organization.
Possibly because of improvements in ocean feeding grounds, returns in 2008 were very positive. On the Penobscot River in Maine, returns were about 940 in 2007, and by mid-July 2008, the return was 1,938. Similar stories were reported in rivers from Newfoundland to Quebec. In 2011, more than 3,100 salmon returned to the Penobscot, the most since 1986, and nearly 200 ascended the Narraguagus River, up from the low two digits just a decade before.
Recovery[edit source | edit]
Around the North Atlantic, efforts to restore salmon to their native habitats are underway, with slow progress. Habitat restoration and protection are key to this process, but issues of excessive harvest and competition with farmed and escaped salmon are also primary considerations. In the Great Lakes, Atlantic salmon have been introduced successfully, but the percentage of salmon reproducing naturally is very low. Most are stocked annually. Atlantic salmon were native to Lake Ontario, but were extirpated by habitat loss and overfishing in the late 19th century. The state of New York has since stocked its adjoining rivers and tributaries, and in many cases does not allow active fishing. Wild salmon on entering rivers as adults have characteristically pointed fins which help scientists distinguish them from farmed or escaped salmon.
In New England, many efforts are underway to restore salmon to the region by knocking down obsolete dams and updating others with fish ladders and other techniques that have proven effective in the West with Pacific salmon. There is some success thus far, with populations growing in the Penobscot and Connecticut Rivers. In Ontario, the Atlantic Salmon Restoration Program was started in 2006, and is one of the largest freshwater conservation programs in North America. It has stocked Lake Ontario with over 700,000 young Atlantic salmon. In October 2007, salmon were video-recorded running in Toronto's Humber River by the Old Mill. In November 2007, a migrating salmon was observed in the Credit River. There has also been some success in establishing Atlantic salmon in Fish Creek, a tributary of Oneida Lake in central New York.
Atlantic salmon, though, remains a popular fish for human consumption. It is commonly sold fresh, canned, or frozen.
Beaver impact[edit source | edit]
The decline in anadromous salmonid species over the last two to three centuries is correlated with the decline in the North American beaver and European beaver, although some fish and game departments continue to advocate removal of beaver dams as pote