Atlantic salmon (Salmo salar) COSEWIC assessment and status report: chapter 1

Assessment Summary

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Assessment Summary

 

Assessment Summary – November 2010

Common name:

Atlantic Salmon – Nunavik population

Scientific name:
Salmo salar

Status:
Data deficient

Reason for designation:
This species requires rivers or streams that are generally clear, cool and well-oxygenated for reproduction and several years of rearing, but undertakes lengthy feeding migrations in the North Atlantic Ocean as older juveniles and adults. This population, which breeds in rivers flowing into Ungava Bay and eastern Hudson Bay, is the northernmost population of the species in North America, and the westernmost population of the entire species. It is separated by approximately 650 km from the nearest population to the south. Little is known about abundance trends in this population, although limited catch per unit effort data suggest increased abundance in recent years.

Occurrence:
Quebec, Newfoundland and Labrador, Atlantic Ocean

Status history:
Species considered in November 2010 and placed in the Data Deficient category.

 

Assessment Summary – November 2010

Common name:

Atlantic Salmon – Labrador population

Scientific name:
Salmo salar

Status:
Not at risk

Reason for designation:
This species requires rivers or streams that are generally clear, cool and well-oxygenated for reproduction and several years of rearing, but undertakes lengthy feeding migrations in the North Atlantic Ocean as older juveniles and adults. This population breeds in rivers along the Atlantic coast of Labrador and southwest along the Quebec coast to the Napetipi Rivers (inclusive). Freshwater habitats remain largely pristine. Abundance data are not available for most rivers; however, for rivers for which data are available, the number of mature individuals appears to have increased by about 380% over the last 3 generations.

Occurrence:
Newfoundland and Labrador, Atlantic Ocean

Status history:
Designated Not at Risk in November 2010.

 

Assessment Summary – November 2010

Common name:

Atlantic Salmon – Northeast Newfoundland population

Scientific name:
Salmo salar

Status:
Not at risk

Reason for designation:
This species requires rivers or streams that are generally clear, cool and well-oxygenated for reproduction and the first few years of rearing, but undertakes lengthy feeding migrations in the North Atlantic Ocean as older juveniles and adults. This population breeds in rivers along the northeast coast of Newfoundland, from the northern tip of the island to the southeastern corner of the Avalon Peninsula. Recent abundance data show no clear trends in the number of mature individuals. Since 1992, the negative effects of poor marine survival have been at least partially offset by a near cessation of fishing mortality in coastal fisheries. Illegal fishing is a threat in some rivers.

Occurrence:
Newfoundland and Labrador, Atlantic Ocean

Status history:
Designated Not at Risk in November 2010.

 

Assessment Summary – November 2010

Common name:

Atlantic Salmon – South Newfoundland population

Scientific name:
Salmo salar

Status:
Threatened

Reason for designation:
This species requires rivers or streams that are generally clear, cool and well-oxygenated for reproduction and the first few years of rearing, but undertakes lengthy feeding migrations in the North Atlantic Ocean as older juveniles and adults. This population breeds in rivers from the southeast tip of the Avalon Peninsula, Mistaken Point, westward along the south coast of Newfoundland to Cape Ray. The numbers of small (one-sea-winter) and large (multi-sea-winter) salmon have both declined over the last 3 generations, about 37% and 26%, respectively, for a net decline of all mature individuals of about 36%. This decline has occurred despite the fact that mortality from commercial fisheries in coastal areas has greatly declined since 1992; this may be due to poor marine survival related to substantial but incompletely understood changes in marine ecosystems. Illegal fishing is a threat in some rivers. The presence of salmon aquaculture in a small section of this area brings some risk of negative effects from interbreeding or adverse ecological interactions with escaped domestic salmon. Genetic heterogeneity among the many small rivers in this area is unusually pronounced, suggesting that rescue among river breeding populations may be somewhat less likely than in other areas.

Occurrence:
Newfoundland and Labrador, Atlantic Ocean

Status history:
Designated Threatened in November 2010.

 

Assessment Summary – November 2010

Common name:

Atlantic Salmon – Southwest Newfoundland population

Scientific name:
Salmo salar

Status:
Not at risk

Reason for designation:
This species requires rivers or streams that are generally clear, cool and well-oxygenated for reproduction and the first few years of rearing, but undertakes lengthy feeding migrations in the North Atlantic Ocean as older juveniles and adults. This population breeds in rivers from Cape Ray northwards along the west coast of Newfoundland to approximately 49°24’ N, 58°15’ W. Both small (one-sea-winter) and large (multi-sea-winter) salmon have increased in number over the last 3 generations, about 132% and 144%, respectively, giving an increase in the total number of mature individuals of about 134%.

Occurrence:
Quebec, Newfoundland and Labrador, Atlantic Ocean

Status history:
Designated Not at Risk in November 2010.

 

Assessment Summary – November 2010

Common name:

Atlantic Salmon – Northwest Newfoundland population

Scientific name:
Salmo salar

Status:
Not at risk

Reason for designation:
This species requires rivers or streams that are generally clear, cool and well-oxygenated for reproduction and the first few years of rearing, but undertakes lengthy feeding migrations in the North Atlantic Ocean as older juveniles and adults. This population breeds in rivers along the west coast of Newfoundland from approximately 49°24’ N, 58°15’ W to the tip of the Great Northern Peninsula. The total number of mature individuals appears to have remained stable over the last 3 generations, and the number of large (multi-sea-winter) salmon appears to have increased by about 42%.

Occurrence:
Newfoundland and Labrador, Atlantic Ocean

Status history:
Designated Not at Risk in November 2010.

 

Assessment Summary – November 2010

Common name:

Atlantic Salmon – Quebec Eastern North Shore population

Scientific name:
Salmo salar

Status:
Special concern

Reason for designation:
This species requires rivers or streams that are generally clear, cool and well-oxygenated for reproduction and the first few years of rearing, but undertakes lengthy feeding migrations in the North Atlantic Ocean as older juveniles and adults. This population breeds in rivers along the north shore of the St. Lawrence River estuary from the Napetipi River (not inclusive) westward to the Kegaska River (inclusive). This population shows opposing trends in the abundance of small (1 sea-winter) and large (multi-sea-winter) fish. Small salmon have declined 26% over the last 3 generations, whereas large salmon have increased 51% over the same period; pooling the data for both groups suggests a decline of about 14% for all mature individuals considered together. The small size of the population, about 5000 mature fish in 2008, is cause for concern. As is the case for most populations of the species, poor marine survival related to substantial but incompletely understood changes in marine ecosystems is also a concern.

Occurrence:
Quebec, Atlantic Ocean

Status history:
Designated Special Concern in November 2010.

 

Assessment Summary – November 2010

Common name:

Atlantic Salmon – Quebec Western North Shore population

Scientific name:
Salmo salar

Status:
Special concern

Reason for designation:
This species requires rivers or streams that are generally clear, cool and well-oxygenated for reproduction and the first few years of rearing, but undertakes lengthy feeding migrations in the North Atlantic Ocean as older juveniles and adults. This population breeds in rivers along the north shore of the St. Lawrence River from the Natashquan River (inclusive) to the Escoumins River in the west (inclusive). Small (one-sea-winter) and large (multi-sea-winter) fish have both declined over the last 3 generations, approximately 34% and 20%, respectively, for a net decline of all mature individuals of about 24%. As is the case for most populations of the species, poor marine survival related to substantial but incompletely understood changes in marine ecosystems is a concern.

Occurrence:
Quebec, Atlantic Ocean

Status history:
Designated Special Concern in November 2010.

 

Assessment Summary – November 2010

Common name:

Atlantic Salmon – Anticosti Island population

Scientific name:
Salmo salar

Status:
Endangered

Reason for designation:
This species requires rivers or streams that are generally clear, cool and well-oxygenated for reproduction and the first few years of rearing, but undertakes lengthy feeding migrations in the North Atlantic Ocean as older juveniles and adults. This population breeds in rivers on Anticosti Island. Small (one-sea-winter) and large (multi-sea-winter) fish have both declined over 3 generations, approximately 32% and 49%, respectively, for a net decline of all mature individuals of about 40%. The population size is small, about 2,400 individuals in 2008. As is the case for most populations of the species, poor marine survival related to substantial but incompletely understood changes in marine ecosystems is a concern.

Occurrence:
Quebec, Atlantic Ocean

Status history:
Designated Endangered in November 2010.

 

Assessment Summary – November 2010

Common name:

Atlantic Salmon – Inner St. Lawrence population

Scientific name:
Salmo salar

Status:
Special concern

Reason for designation:
This species requires rivers or streams that are generally clear, cool and well-oxygenated for reproduction and the first few years of rearing, but undertakes lengthy feeding migrations in the North Atlantic Ocean as older juveniles and adults. This highly managed population breeds in rivers tributary to the St. Lawrence River upstream from the Escoumins River (not included) on the north shore and the Ouelle River (included) on the south shore. Small (one-sea-winter) and large (multi-sea-winter) fish have both remained approximately stable in abundance over the last 3 generations. The small size of the population, about 5,000 individuals in 2008, is of concern. The rivers in this area are close to the largest urban areas in Quebec and the population has undergone a large historical decline due to loss of habitat. As is the case for most populations of the species, poor marine survival related to substantial but incompletely understood changes in marine ecosystems is a concern.

Occurrence:
Quebec, Atlantic Ocean

Status history:
Designated Special Concern in November 2010.

 

Assessment Summary – November 2010

Common name:

Atlantic Salmon – Lake Ontario population

Scientific name:
Salmo salar

Status:
Extinct

Reason for designation:
Once a prolific resident throughout the Lake Ontario watershed, there has been no record of this population since 1898. The Lake Ontario population was extinguished through habitat destruction and through over-exploitation by food and commercial fisheries. As the original strain is gone, re-introduction is not possible. Recent attempts to introduce other strains of the species have resulted in some natural reproduction, but no evidence of self-sustaining populations.

Occurrence:
Ontario, Atlantic Ocean

Status history:
Last reported in 1898. Designated Extirpated in April 2006. Status re-examined and designated Extinct in November 2010.

 

Assessment Summary – November 2010

Common name:

Atlantic Salmon – Gaspé-Southern Gulf of St. Lawrence population

Scientific name:
Salmo salar

Status:
Special concern

Reason for designation:
This species requires rivers or streams that are generally clear, cool and well-oxygenated for reproduction and the first few years of rearing, but undertakes lengthy feeding migrations in the North Atlantic Ocean as older juveniles and adults. This population breeds in rivers from the Ouelle River (excluded) in the western Gaspé Peninsula southward and eastward to the northern tip of Cape Breton. Small (one-sea-winter) and large (multi-sea-winter) fish have both declined over the last 3 generations, approximately 34% and 19%, respectively, for a net decline of all mature individuals of about 28%. This recent 3-generation decline represents a continuation of a decline extending back at least to the 1980s. The number of mature individuals remains over 100,000; however, the majority spawn in a single major river system, the Miramichi, in New Brunswick. Freshwater habitat quality is a concern in some areas, particularly in Prince Edward Island where some remaining populations are maintained by hatchery supplementation. Invasive and illegally introduced species, such as smallmouth bass, are a poorly understood threat in some freshwater habitats. Poor marine survival is related to substantial but incompletely understood changes in marine ecosystems.

Occurrence:
Quebec, New Brunswick, Nova Scotia, Atlantic Ocean

Status history:
Designated Special Concern in November 2010.

 

Assessment Summary – November 2010

Common name:

Atlantic Salmon – Eastern Cape Breton population

Scientific name:
Salmo salar

Status:
Endangered

Reason for designation:
This species requires rivers or streams that are generally clear, cool and well-oxygenated for reproduction and the first few years of rearing, but undertakes lengthy feeding migrations in the North Atlantic Ocean as older juveniles and adults. This population breeds in Cape Breton Island rivers draining into the Atlantic Ocean and Bras d’Or Lakes. The numbers of adults returning to spawn has declined by about 29% over the last 3 generations; moreover, these declines represent continuations of previous declines. The total number of mature individuals in 5 rivers, thought to harbour the majority of the population, was only about 1,150 in 2008. There is no likelihood of rescue, as neighbouring regions harbour genetically dissimilar populations, and the population to the south is severely depleted. A current threat is poor marine survival related to substantial but incompletely understood changes in marine ecosystems.

Occurrence:
Nova Scotia, Atlantic Ocean

Status history:
Designated Endangered in November 2010.

 

Assessment Summary – November 2010

Common name:

Atlantic Salmon – Nova Scotia Southern Upland population

Scientific name:
Salmo salar

Status:
Endangered

Reason for designation:
This species requires rivers or streams that are generally clear, cool and well-oxygenated for reproduction and the first few years of rearing, but undertakes lengthy feeding migrations in the North Atlantic Ocean as older juveniles and adults. This population breeds in rivers from northeastern mainland Nova Scotia, along the Atlantic coast and into the Bay of Fundy as far as Cape Split. Small (one-sea-winter) and large (multi-sea-winter) fish have both declined over the last 3 generations by approximately 59% and 74%, respectively, for a net decline of all mature individuals of about 61%. Moreover, these declines represent continuations of greater declines extending far into the past. During the past century, spawning occurred in 63 rivers, but a recent (2008) survey detected juveniles in only 20 of 51 rivers examined. There is no likelihood of rescue, as neighbouring regions harbour severely depleted, genetically dissimilar populations. The population has historically suffered from dams that have impeded spawning migrations and flooded spawning and rearing habitats, and other human influences, such as pollution and logging, that have reduced or degraded freshwater habitats. Acidification of freshwater habitats brought about by acidic precipitation is a major, ongoing threat, as is poor marine survival related to substantial but incompletely understood changes in marine ecosystems. There are a few salmon farms in this area that could lead to negative effects of interbreeding or ecological interactions with escaped domestic salmon.

Occurrence:
Nova Scotia, Atlantic Ocean

Status history:
Designated Endangered in November 2010.

 

Assessment Summary – November 2010

Common name:

Atlantic Salmon – Inner Bay of Fundy population

Scientific name:
Salmo salar

Status:
Endangered

Reason for designation:
This species requires rivers or streams that are generally clear, cool and well-oxygenated for reproduction and the first few years of rearing, but undertakes feeding migrations in the North Atlantic Ocean as older juveniles and adults. This population once bred in 32 rivers tributary to the inner Bay of Fundy, from just east of the Saint John River, to the Gaspereau River in Nova Scotia; however, spawning no longer occurs in most rivers. The population, which is thought to have consisted of about 40,000 individuals earlier in the 20th century, is believed to have been fewer than 200 individuals in 2008. Survival through the marine phase of the species’ life history is currently extremely poor, and the continued existence of this population depends on a captive rearing program. There is no likelihood of rescue, as neighbouring regions harbour severely depleted, genetically dissimilar populations. The population has historically suffered from dams that have impeded spawning migrations and flooded spawning and rearing habitats, and other human influences, such as pollution and logging, that have reduced or degraded freshwater habitats. Current threats include extremely poor marine survival related to substantial but incompletely understood changes in marine ecosystems, and negative effects of interbreeding or ecological interactions with escaped domestic salmon from fish farms. The rivers used by this population are close to the largest concentration of salmon farms in Atlantic Canada.

Occurrence:
New Brunswick, Nova Scotia, Atlantic Ocean

Status history:
Designated Endangered in May 2001. Status re-examined and confirmed in April 2006 and November 2010.

 

Assessment Summary – November 2010

Common name:

Atlantic Salmon – Outer Bay of Fundy population

Scientific name:
Salmo salar

Status:
Endangered

Reason for designation:
This species requires rivers or streams that are generally clear, cool and well-oxygenated for reproduction and the first few years of rearing, but undertakes lengthy feeding migrations in the North Atlantic Ocean as older juveniles and adults. This population breeds in rivers tributary to the New Brunswick side of the Bay of Fundy, from the U.S. border to the Saint John River. Small (one-sea-winter) and large (multi-sea-winter) fish have both declined over the last 3 generations, approximately 57% and 82%, respectively, for a net decline of all mature individuals of about 64%; moreover, these declines represent continuations of greater declines extending far into the past. There is no likelihood of rescue, as neighbouring regions harbour severely depleted, genetically dissimilar populations. The population has historically suffered from dams that have impeded spawning migrations and flooded spawning and rearing habitats, and other human influences, such as pollution and logging, that have reduced or degraded freshwater habitats. Current threats include poor marine survival related to substantial but incompletely understood changes in marine ecosystems, and negative effects of interbreeding or ecological interactions with escaped domestic salmon from fish farms. The rivers used by this population are close to the largest concentration of salmon farms in Atlantic Canada.

Occurrence:
New Brunswick, Atlantic Ocean

Status history:
Designated Endangered in November 2010.

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