Aerial photos from the Aug 19th, 2015 survey of the Western Hudson Bay beluga population

PURPOSE: An aerial survey of the Western Hudson Bay beluga whale (Delphinapterus leucas) population was conducted on August 19th, 2015 to provide a population estimate. Surveys were flown in a DeHavilland Twin Otter (DH-6) fitted with four bubble windows and an optical glass-covered camera hatch at the rear underbelly of the plane. A Global Positioning System (GPS) unit logged the position, altitude, speed, and heading of the aircraft each second. Surveys were initially flown at a target ground speed of 100 knots (185 km/h), and target altitudes of 1,000 ft (305 m) for visual surveys and 2,000 ft (610 m) for photographic surveys. After the second day of flying, the target ground speed was adjusted to 110 knots (204 km/h).

Complete coverage of the two photographic strata was achieved using a Nikon D810 camera fitted with a 25 mm lens. The camera was mounted at the rear of the aircraft and directed straight down with the longest side perpendicular to the track line. The camera was connected to a GPS unit to geo-reference photographs, and to a laptop computer to control exposure settings and photo interval. At an altitude of 2,000 ft (610 m), the 25 mm lens captured a ground area of approximately 875 m x 585 m. The photograph interval was set to maintain an overlap of 20 to 40 % between consecutive photos, and with a transect spacing of 600 m, the lateral overlap between photos from adjacent transects was approximately 30 %.

DESCRIPTION: Aerial surveys of summering Western Hudson Bay (WHB) beluga (Delphinapterus leucas) were conducted on August 19th, 2015 to update the previous population abundance. The survey area comprised five strata (three visual and two photographic) encompassing high use areas around three river estuaries where recurring aggregations of WHB beluga are found during the summer months. This metadata covers the photographic data related to the survey. The photographic surveys completely covered high density aggregations in the Churchill River and near the mouth of the Seal River.

Data and Resources

Additional Info

Field	Value
Last Updated	April 17, 2026, 21:19 (UTC)
Created	April 17, 2026, 21:19 (UTC)
contact_email	marianne.marcoux@dfo-mpo.gc.ca
contact_person	{"en": "Government of Canada; Fisheries and Oceans Canada", "fr": "Gouvernement du Canada; Pêches et Océans Canada"}
criticality_level	[]
data_dictionary	EPSG:4326,https://epsg.io,
geographic_scope	[]
open_canada_collection	fgp
open_canada_date_published	2024-06-25 00:00:00
open_canada_keywords	{"en": ["delphinapterus leucas", "Western Hudson Bay", "beluga", "stock assessment", "aerial survey", "aerial photography", "Biological Classification", "Animals/Vertebrates", "Toothed Whales", "Aquatic Ecosystems", "Oceans", "Aerial photography", "Aquatic wildlife", "Biological diversity", "Fisheries resources", "Habitats", "Marine biology", "Oceans", "Whales", "Arctic Ocean", "Hudson Bay and James Bay"], "fr": ["delphinapterus leucas", "ouest de la baie d’Hudson", "béluga", "évaluation des stocks", "relevé aérien", "photographie aérienne", "classification biologique", "animaux/vertébrés", "odontocètes (cétacés à dents)", "écosystèmes aquatiques", "océans", "Photographie aérienne", "Faune aquatique", "Diversité biologique", "Ressources halieutiques", "Habitat", "Biologie marine", "Océan", "Baleine", "Océan Arctique", "Baie d''Hudson et Baie James"]}
open_canada_subject	["nature_and_environment", "science_and_technology"]
sensitivity_level	unrestricted
title_fr	Photos aériennes du relevé de la population de bélugas de l’ouest de la baie d’Hudson du 19 août 2015
update_frequency	not_planned