Important habitats of the North Atlantic Right Whale (Eubalaena glacialis) in Eastern Canadian Waters

Abstract

Changes in North Atlantic right whale (NARW; Eubalaena glacialis) demography, population dynamics, and distribution, beginning in 2010, highlighted the need for an updated assessment of important habitat in Canadian waters to support their recovery and survival. NARWs rely on a variety of eastern Canadian habitats for foraging, rearing, socializing, mating, and migration. NARWs depend on specific habitat features and attributes vital for these functions, and destruction of the habitat can negatively impact their survival and recovery. A key driver of NARW habitat use in Canadian waters is prey availability and the formation of dense prey aggregations, which are influenced by biophysical processes. NARWs also require unimpeded space and connectivity among habitats to move within and between them. In eastern Canada, NARW sightings occur year-round, with the exception of March, and NARW upcalls are detected through acoustic monitoring efforts in all months, though infrequently from December through March. Directed prey research in the southern Gulf of St. Lawrence indicates persistent and suitable foraging conditions supported by local environmental, oceanographic, and bathymetric conditions. Various data sources including NARW sightings, acoustic detections, persistence of predicted foraging habitat based on prey modeling, and a probability of occurrence model, were used to identify important habitats for NARWs in eastern Canadian waters, as well as to describe their functions, features and attributes. The resulting important habitat for feeding, reproduction, rearing, socializing and socialization is comprised of the southern and northwestern Gulf of St. Lawrence, including the Jacques-Cartier Strait and entrance to Chaleur Bay; the Scotian Shelf, especially Emerald and Roseway Basins; the Bay of Fundy; and the Canadian portions of Georges Bank and the Gulf of Maine. The important habitat also includes corridors for migratory movements and habitat connectivity, namely, the Laurentian Channel, Cabot Strait, and the eastern portion of the Scotian Shelf. Additionally, potential foraging areas were identified in coastal waters of the eastern Scotian Shelf and around Newfoundland, at the southern and eastern edges of the Grand Banks, the Flemish Cap, and in the northeast portion of the Jacques Cartier Strait. Many threats may impact NARW habitat. Commonly occurring anthropogenic activities that could potentially destroy NARW habitat include fishing activities, vessel traffic in the marine environment, industrial activities, and energy development and production. For each of these activities, the pathways of effects on habitat functions, features, and attributes are described. Disruptions to the environmental features supporting vital functions, whether due to localized circulation changes, anthropogenic activities, or large-scale climate shifts, could lead to the loss or alteration of suitable habitats, potentially impacting NARW distribution, health, and reproduction.