The Beluga whale critical habitat, which includes the Upper Estuary, the Saguenay River up to Sainte-Marguerite Bay, and the southern channel of the Lower Estuary, supports the vital functions of calving and rearing of the young. Due to the lack of information, studies are planned in the near future to increase knowledge of the species. Critical habitat actual limitations could change someday. Purpose The beluga (Delphinapterus leucas) population in the St. Lawrence Estuary was greatly reduced by hunting, which was finally banned in the St. Lawrence in 1979. In May 2005, this beluga population was officially listed as a threatened species on SARA’s List of Wildlife Species at Risk. Additional Information St. Lawrence beluga critical habitat is identified using the best available information. All the available information on its prey, seasonal distribution, use and characteristics of its habitat has been reviewed by Mosnier (2010). This literature review was used to produce a science advisory report reviewed by marine mammal experts. Beluga whale critical habitat has been identified with the information and the scientific advice, using the area of occupancy approach and corresponds to the summer distribution of groups made up of adults and new-born calves and juveniles. Mosnier, A., Lesage, V., Gosselin, J.-F., Lemieux Lefebvre, S., Hammill, M. O., Doniol-Valcroze, T. 2010. Information relevant to the documentation of habitat use by St. Lawrence beluga (Delphinapterus leucas), and quantification of habitat quality. DFO Can. Sci. Advis. Sec., Res. Doc. 2009/098. iv + 35 p. DFO. 2012. Recovery Strategy for the beluga whale (Delphinapterus leucas) St. Lawrence Estuary population in Canada. Species at Risk Act Recovery Strategy Series. Fisheries and Oceans Canada, Ottawa. 88 pp + X pp.

This layer represents the seasonal distribution of the St. Lawrence Estuary beluga whale population (Delphinapterus leucas). Three groups are represented: females with calf, adult males and mixed sectors. Herd distribution was defined using Fisheries and Oceans Canada (DFO) published data about beluga whales (see references). Herd distribution areas are only valid during the summer, and the uses of these areas by the herds are unknown. Data source : Michaud, R. 1993. Distribution estivale du béluga du St-Laurent; synthèse 1986-1992. Can. Tech. Rep. Fish. Aquat. Sci. 1906: vi + 28 p.

This layer represents the seasonal distribution of St. Lawrence Estuary beluga whale population (Delphinapterus leucas). Summer distribution is based on many surveys conducted between the end of August and early September. Fall and winter distributions are based on aerial surveys conducted during mid-October, November and from December to March 1989-1990. Spring distribution is based on anecdotal reports and two aerial surveys conducted in late April and early June 1990. Beluga whale seasonal distribution can change according to sea ice cover, predation risk and food availability. This layer represents the general seasonal distribution and does not account for the sexual segregation among males and females in the St. Lawrence Estuary. This layer do not represent the beluga's critical habitat. See the data layer “Beluga whale critical habitat in the Saguenay River and the St. Lawrence Estuary” (https://open.canada.ca/data/en/dataset/fdfef550-b94c-466c-9dcb-24c297c00e3e). Data source : Mosnier, A., Lesage, V., Gosselin, J.-F., Lemieux Lefebvre, S., Hammill, M. O., Doniol-Valcroze, T. 2010. Information relevant to the documentation of habitat use by St. Lawrence beluga (Delphinapterus leucas), and quantification of habitat quality. DFO Can. Sci. Advis. Sec., Res. Doc. 2009/098. iv + 35 p.

This layer represents the relative summer density of beluga calves in the St. Lawrence Estuary based on 35 aerial surveys carried out from 1990 to 2009. The boundaries of the areas were determined by combining the highest densities until the desired proportion of the population was obtained using kernel density estimation in order to obtain a smooth and continuous density distribution. Within Fisheries and Oceans Canada (DFO), the ecosystem approach is considered as a tool for operational planning, project implementation and preparation of advisory reports. In response to this strategic direction, the DFO science division is committed to implement the ecosystem approach in its activities as Ecosystem Research Initiatives (ERI) in each of the six administrative regions of DFO. In the Quebec region, two pilot projects were implemented, of which one aimed to define and characterize the habitat of the St. Lawrence beluga (Delphinapterus leucas). Data sources and references: DFO. 2016. Ecosystem Research Initiative (ERI): Integrated Advice on the Summer Habitat of the St. Lawrence Estuary Beluga (Delphinapterus leucas). DFO Can. Sci. Advis. Sec. Sci. Advis. Rep. 2016/030. Mosnier, A., R. Larocque, M. Lebeuf, J.-F. Gosselin, S. Dubé, V. Lapointe, V. Lesage, V., H. Bourdages, D. Lefaivre, S. Senneville and C. Chion. 2016. Définition et caractérisation de l'habitat du béluga (Delphinapterus leucas) de l'estuaire du Saint-Laurent selon une approche écosystémique. Secr. can. de consult. sci. du MPO. Doc. de rech. 2016/052. vi + 93 p.

To identify areas of high residency, fine-scale tracking data from individual animals and coarser, short-term movement patterns of herds were analyzed. Individual radio-tracking was assessed from 2001 to 2005 and herd visual tracking was assessed from 1989 to 2008. Data was collected by two research teams: GREMM (Groupe de recherche et d’éducation sur les mammifères marins) and Fisheries and Océans Canada (DFO). Areas of high residency were determined using net displacement speed of herds and they were defined as adjacent cells where 50% of the herds travelled at or below a threshold speed. Areas of high residency do not represent the general distribution of the beluga whale and no association between these areas and specific biological functions could be established. The exact delimitation of these areas can change according to the definition criteria used in the analysis. Therefore, the marginal cells are not necessarily indicative of lower habitat quality. Data source: Lefebvre, S., Michaud, R., Lesage, V. and Berteaux, D. (2012). Identifying high residency areas of the threatened St. Lawrence beluga whale from fine-scale movements of individuals and coarse-scale movements of herds. Mar. Ecol. Prog. Ser. 450: 243–257.

This layer represents the relative summer density of belugas in the St. Lawrence Estuary based on 35 aerial surveys carried out from 1990 to 2009. The boundaries of the areas were determined by combining the highest densities until the desired proportion of the population was obtained using kernel density estimation in order to obtain a smooth and continuous density distribution. Within Fisheries and Oceans Canada (DFO), the ecosystem approach is considered a tool for operational planning, project implementation and preparation of advisory reports. In response to this strategic direction, the DFO science division is committed to implement the ecosystem approach in its activities as Ecosystem Research Initiatives (ERI) in each of the six administrative regions of DFO. In the Quebec region, two pilot projects were implemented, of which one aimed to define and characterize the habitat of the St. Lawrence beluga (Delphinapterus leucas). Data sources and references: DFO. 2016. Ecosystem Research Initiative (ERI): Integrated Advice on the Summer Habitat of the St. Lawrence Estuary Beluga (Delphinapterus leucas). DFO Can. Sci. Advis. Sec. Sci. Advis. Rep. 2016/030. Mosnier, A., R. Larocque, M. Lebeuf, J.-F. Gosselin, S. Dubé, V. Lapointe, V. Lesage, V., H. Bourdages, D. Lefaivre, S. Senneville and C. Chion. 2016. Définition et caractérisation de l'habitat du béluga (Delphinapterus leucas) de l'estuaire du Saint-Laurent selon une approche écosystémique. Secr. can. de consult. sci. du MPO. Doc. de rech. 2016/052. vi + 93 p.