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Text from: Canada (1989), Espèces en difficulté dans le Saint-Laurent
Description
Shape:
Spindle shaped, with a large and terminal mouth, and a slightly forked tail. The salmon has a dorsal fin and another one, adipose, near the tail. Variable coloration according to the development phase. In the sea: white belly, silver sides and brown, green or blue-grey back with black spots. Loses its silver colour in rivers and becomes brown with reddish spots on its sides. Near spawn time, the head of the male becomes longer while its inferior jaw becomes larger and hooked at its extremity.
Length and Weight:
Largely defined by the number of years spent at sea: from 1,5 to 2,5 kg and 50 cm after one year, from 3 to 6 kg and 75 cm after two years and 7 to 12 kg and 90 cm after three years of living at sea. The biggest specimens, having spawned many times, can weigh over 25 kg.
Reproduction :
Typical anadromous fish. After a stay of one to three years, sometimes four, at sea, it comes back to its native river to reproduce. The spawn happens in autumn, between the end of October and November in shallow running water with a gravel bottom. Some individuals will reproduce more than once.
Longevity:
About seven years.
Diet:
In rivers, juveniles will feed mostly from insects. At sea, the adults' diet is varied. Crustaceans, sand eels, smelts, capelins, kippers and mackerels are its main menu. Back to the river, the breeders stop feeding.
Habitat:
When they leave the river, the smolts stay along the North coast of the St-Lawrence before migrating to the feeding grounds near Newfoundland and Greenland. Back to their native river, salmons use the inshore waters of the estuary as a migratory path. The Jacques-Cartier River, on the north shore, and the Ouelle River on the south shore mark the salmon's sighted limits of penetration in the St-Lawrence estuary.
Main Predators:
In rivers, the eggs, the alevin and the juveniles are prey of other fish such as the brook trouts, the white suckers and the eels, besides being part of the diet of many birds (mergansers, kingfishers, gulls, cormorants) and mammals (minks, otters). At sea, the adult is mostly prey to cods, pollocks and tunas.
Other Names:
Although the nomenclature of the development phases is elaborated, the adult is mainly called salmon, Atlantic salmon and Salmo salar. The one sea-winter (1SW) salmon and grilse terms are used for adults who are back to the rivers after a one-year stay at sea, or else they are called multi-sea-winter (MSW) salmons or great salmons. Confined to freshwaters, it is called freshwater salmon, landlocked salmon or Sebago. 
Current Situation
The Atlantic salmon can be found throughout the North Atlantic. In Québec, historical accounts largely state its past abundance in many tributaries of the St-Lawrence estuary, including most rivers around Québec City, such as Saint-Charles, Jacques-Cartier and Sainte-Anne rivers.
Up to the 20th century, the salmon has been abundant in most tributaries of the St-Lawrence downstream from Québec, meaning those that gave access to a suitable habitat.
The generalized lowering of stocks observed in Québec since the 40s would be due to the overexploitation of commercial fishing. Besides, the fluctuations observed in the lspawning runs in Québec since the 60s, coincide with the commercial unloading made via an intensive loffshore fishery practiced near the Greenland. The salmon is haunted in its sea feeding areas, actively exploited during its migrations and fished as a sport or poached in rivers, often without any consideration. These numerous assaults could bring it to its limits of recuperation.
The generalized deficit of breeders, from 1982 and 1983, has brought severe restrictions for any form of exploitation and the increase in efforts for restoring the species. The different measures applied allowed for a certain adjustment of the situation, but the species is still considered as fragile.
Preferred Habitats along the St-Lawrence
The St-Lawrence estuary represents only a part of the salmon's habitat. Its costal waters are used by the smolts as a migratory path, heading to the sea feeding areas, and by the breeders when they return to spawn in the river.
The river habitat is better known. In the estuary portion of interest, there are 13 Salmon rivers on the north shore and 7 on the south shore of the St-Lawrence, which is about 15 % of all the province's rivers. It is mostly tributaries where the water is cold with a rapid flow. The layout of the different flow patterns (rapids, pools, trenches and channels) make excellent habitats for spawning and the development of the juvenile phases.
The marine habitats of the Salmon located near the Greenland, in the Labrador Sea and to the East of Newfoundland favour the salmon's nutrition and growth because of its cold and productive waters.
Species Biology
After staying at sea for one to three years, sometimes four, the salmon returns to its native river to reproduce. The specimens coming back after one year are called grilses or one sea-winter (1SW) salmons. The others are called two sea-winter (2SW) salmons (two years at sea), three sea-winter (3SW) salmons (three years) or, more generally, multi-sea-winter (MSW) salmons or great salmons . The number of years spent at sea determines largely the weight of the Salmon when it arrives in fresh waters; 1,5 to 2,5 kg after one year, 3 to 6 kg after two years and 7 to 12 kg after three years. The specimens who come back to spawn more than once are called repeat spawners or multiple spawn breeders, and can weigh up to 25 kg.
Different hypotheses were made to explain the mechanisms that set in motion and govern the migratory travels, but none is unanimously accepted by the scientific community. The magnetic orientation, the star and sun navigation, the influence of the sea currents and remembering the native river's smell via chemical substances (pheromones) secreted by the juveniles in the river would intervene at different levels in the recognition process of the native river.
The arrival of the breeders at the mouth of the river can be spread over several months. The biggest individuals arrive first; this first contingent usually migrates in the river from May to July. Around the middle of this first arrival, concentrations of grilses gradually appear. In some rivers, the ascent of large Salmons can continue until the beginning of October. The proportion of large Salmons or grilses varies from one river to another and from one season to the other. Some rivers produce only grilses, others, only older individuals.
No matter the arrival date of the Salmon at the mouth of the river, the ascent to the spawning areas is generally made after a short adaptation in brackish water. The spawning run . rhythm varies enormously in function of the hydrological rate and the severity of the obstacles that punctuate the bed of the target river. The salmons seem to be less active when the water is high or very low and are more active at night than during the day. It is during this complex process where the maturation of the gonads . and the migration from the marine habitats are linked that the inferior jaw of the male becomes like a hook curved upwards and that its coloration changes. This change in coloration is less obvious with the females.
Spawn begins in October and November, on a gravel bottom, in live shallow waters. The female digs a nest with her tail and lays her eggs that are instantly fertilized by one or many adult, even juvenile, males. It is not rare that male parrs, who have reached their sexual maturity, participate actively in this activity. The number of eggs produced is about 1 500 per kilogram of body weight.
The incubation period is of 160 to 200 days. The hatching happens at the end of winter, but the fry come out of the gravel only a week later. The juvenile salmons, called parrs, have a typical coloration, a diet based on the drifting invertebrates and a territorial behaviour. The productivity of rivers directly depends on the areas available for the development of parrs.
On the Côte-Nord, life in the river can last from 2 to 5 years. At the end of the stay in fresh waters, the parrs become silver and are gregarious ; they are then called smolts. They go down to the rivers' estuary in spring, where they become acclimatized to salt water, before undertaking their migration towards marine feeding areas.
It is generally admitted that, on a total of 8 000 fertilized eggs, only four individuals will reproduce in the river, although this number varies since it depends on the sea interceptions. After having spawned, the salmon is called the black salmon or racers. Many go back at sea after a first spawn, but only 5 % of the breeders will come back a second time to spawn after having restored themselves at sea.
The knowledge regarding the feeding marine zones and the migratory paths are fragmentary. At sea, the salmon eats a variety of fish such as the herring, capelin, sand eel and the mackerel. The crustaceans, like the shrimps and euphausids , are also on the menu.
In the rivers, the juveniles are prey to other fish, birds and some mammals. At sea, the smolts and growing salmons are prey to fish like the cod, pollock and tuna. The seal also eats the salmon caught in fishing engines. In our waters, the specie is host to a variety of internal land external parasites, who are without consequence for its survival.
Exploitation by men
The Québec salmon is exploited at sea, in its feeding areas. Once in our costal waters, commercial fisheries will capture a certain amount downstream from Franquelin, fishing being forbidden for the rest of the Haute and Moyenne Côte-Nord, in the Gaspé Peninsula and the Bas-Saint-Laurent. Subsistence fishing is practiced in a few rivers by the natives and, finally, at the exception of rivers in restoration, the sportive fishermen also do their part in capturing salmons. To this general view of the salmon exploitation, we must add illegal fishing.
In the costal waters, the gill nets and bag nets are used for the commercial capture of the salmon, while in the river, the sportive fishermen use fishing rods usually baited with artificial flies, without sinker, meaning drowned or dry. The economical repercussions linked to the sportive fishing of the salmon are proportionally higher than any other species'.
The reputation of the Atlantic salmon is due to the excellence of its flesh and its combativeness. It is sold fresh, frozen or smoked, but rarely in cans contrary to its counterpart the Pacific salmon.
Causes of Decline
Since at one phase or another of its life the salmon is faced with human exploitation, in one form or another, it is not surprising that overexploitation is one of the main threats to its survival. In the St-Lawrence network, the salmon has been abundant until the 20th Century, everyplace where it had access to a suitable habitat. The lower numbers have been attributed to the loss of access to some rivers, such as the Jacques-Cartier.
A decrease in stocks and changes in the grilses/great salmons relationship were observed when intensive fishing was practiced near the Greenland, starting in 1960. The captures reached a maximum of 2 689 t. in 1971. Because of the stocks decline, offshore fishing was submitted to a decreasing limit until it reached zero in 1976. Costal fishing, still practiced in 1990, is limited to less than 1 000 t.
The decrease in stocks has also been felt by sportive fishing in Québec. At the beginning of the 80s, over 20 000 sportive fishing permits were sold yearly for the salmon. In 1984, those sales dropped to 12 500, but their number is increasing gradually since that time.
In addition to the overexploitation of stocks, the damages made to the aquatic habitats very likely did not help the salmon's cause. The domestic or industrial pollution, the encroachment of the banks and the deforestation of the catchment areas could have insidious local effects. The rivers of the Côte-Nord would be less exposed to these problems; however they are more vulnerable to the effects of acid rains.
Facing a particularly bad gathering in Québec and a generalized deficit in the breeders in 1982 and 1983, the Québec government has imposed severe restrictions to all types of exploitation starting in 1984. It seems that the measures applied allowed a certain adjustment of the situation.
Still today, the fishing offer is still inferior to the request.
Need of Knowledge and Corrective Measures
It would take too long to list the measures taken to save or improve the salmon population and their natural habitat. The work accomplished in this field is enormous and includes, among others, the construction of fish ladders or other mechanical device to allow salmons to overcome obstacles in the river, the yearly release of young salmons from different stocks, produced in the three fish-breeding stations operated under the care of the Québec government, the restoration of rivers formerly used by the salmons, such as the Jacques-Cartier, the rivière du Gouffre and Escoumins and the reconditioning of black salmons. The most recent measures target poaching, and try to limit accidental captures made during other captures and the sea gathering of mixed stocks. There is also the stock breeding of adult salmons for the food market.
Within the framework of the Canada Québec auxiliary understanding on the development of Québec regions, the federal and provincial governments ratified a five-year plan for the economic development of the salmon from 1991 to 1996. Of a value of $24 million, this agreement includes four types of interventions: the elaboration of an improvement plan by river, the development or improvement of techniques for the promotion of the environment, activities for the improvement and development of advice services for non-profit organizations admissible to the program.
On a short-term basis, the knowledge needs target the evaluation, by river, of the increase potential in production of grilses and smolts, by the restoration of the habitats or by the improvement of their accessibility.
On a medium-term basis, the needs are to better evaluate the real productivity of rivers, to improve the management of the resource by hydro graphic basin. This implies a better understanding of the influence of the physical components of the habitat that govern the production of young salmons. On the Côte-Nord in particular, it would be desirable if the number of breeders left in the river was better evaluated.
Suggested Readings
Canada (1989). Espèces en difficulté dans le Saint-Laurent. Le Saumon atlantique. Pêches et oceans. Plan d'action Saint-Laurent.
ANDERSEN, A. et M. GAGNON. 1980. Les ressources halieutiques de l'estuaire du Saint-Laurent. Rapp. can. ind. sci. halieut. aquat. 119: iv + 56 p.
COTÉ, Y. 1976. Le saumon. Série Faune du Québec. Ministère du Tourisme, de la Chasse et de la Pêche, Québec. Brochure no 12: 8 p.
MARQUIS, H., J. THERRIEN, P. BÉRUBÉ et G. SHOONER. 1990. Modifications physiques de l'habitat du poisson en amont de Montréal et en aval de Trois-Pistoles de 1945 à 1988 et effets sur les pêches commerciales. Étude réalisée par Gilles Shooner et Associés pour le compte des ministères des Pêches et des Océans et de l'Environnement du Canada. 146 pages + 4 annexes.
ROBITAILLE, J. A. et Y. MAILHOT. 1989. Dynamique et statut des populations de poissons du Saint-Laurent: état des connaissances. Ministère du Loisir, de la Chasse et de la Pêche du Québec, Direction de la gestion des espèces et des habitats et Direction régionale Mauricie, Bois-Francs. Rapp. tech. 51 p.
ROBITAILLE, J. A., L. CHOINIÈRE et Y. VIGNEAULT. 1989. Identification des populations de poissons d'intérêt économique en situation précaire dans le réseau du Saint-Laurent et sélection des espèces pour des interventions immédiates. Rapp. tech, can. soi. halieut. aquat., 1810: ix + 24p.
SCOTT, W. B. et M. G. SCOTT. 1988. Atlantic fishes of Canada. Can. Bull. Fish. Aquat. Sci. 219: 731 p.
SMITH, K. E. H. 1988. Le saumon de l'Atlantique, Série le Monde sous-marin. Direction générale des communications, ministère des Pêches et des Océans, Ottawa. 8 p.
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