Sackville Spur and Orphan Basin IMMA

Criterion A: Species or Population Vulnerability

The blue (Balaenoptera musculus) and sei whale (Balaenoptera borealis) are listed as Endangered on the Red List globally (Cooke 2018a,b), and the fin whale (Balaenoptera physalus) and sperm whale (Physeter macrocephalus) are both listed as Vulnerable on the Red List globally (Cooke 2018c, Taylor et al. 2019).

Criterion B: Distribution and Abundance

Sub-criterion B2: Aggregations

Sighting rates of groups (per hour equivalent in excellent conditions) from a 12m research sailing vessel between 2001-2017 from June to August were considerably higher in and around the Sackville Spur-Orphan Basin region (149 hours effort) than other areas along the edge of the Newfoundland Shelf (140 hours effort) for the following species: pilot whales (Globicephala melas; 0.355 vs 0.043); northern bottlenose whales (Hyperoodon ampullatus; 0.194 vs 0.000); sperm whales (0.321 vs 0.036) (Whitehead and Feyrer unpublished).  Additionally, a comprehensive habitat analysis identified this region as the second most important year-round habitat for northern bottlenose whales in the western North Atlantic after the eastern canyons region of the Scotian Shelf, and also highlighted this area as part of important habitat for Sowerby’s beaked whales (Mesoplodon bidens; Feyrer et al. 2024). An analysis of 25 acoustic recorders deployed off eastern Canada between May 2015 and November 2017 identified the Sackville Spur area as especially important for northern bottlenose whales year-round with northern bottlenose whale foraging clicks detected on 25-75% of recording days for two hydrophones deployed in the eastern and western ends of the area in all four seasons (Delarue et al. 2024). Drivers of enhanced densities of marine mammals in the Sackville Spur-Orphan Basin region are not clear, but likely relate to the cold, southeast-flowing Labrador Current interacting with the complex bathymetry on the northeast corner of the Grand Banks (Maillet et al. 2006).

Criterion C: Key Life Cycle Activities

Sub-criterion C2: Feeding Areas

The strong, cold Labrador Current which flows southeast along the edge of the continental shelf off Labrador and northeast Newfoundland creates highly productive conditions when it encounters the rises of the Sackville Spur and Orphan Knoll at the northeast corner of the Grand Banks (Maillet et al. 2006). Northern bottlenose whales and sperm whales have been frequently observed feeding in the Sackville Spur region (Hal Whitehead, pers. comm). Northern bottlenose whales and Sowerby’s beaked whales were also acoustically detected foraging in the area year-round (Delarue et al. 2024, Feyrer et al. 2024).

Criterion D: Special Attributes

Sub-criterion D2: Diversity

With regular presence of more than 11 marine mammal species, this area supports a high species diversity. This is evidenced by a concentration of cetacean sighting records of free-swimming cetaceans collected during the post-whaling period (1975 – 2015) (Gomez et al, 2020).  As discussed above, sighting rates from vessel-based surveys conducted over multiple years within this area were found to be higher for northern bottlenose, Sowerby’s beaked, sperm, and pilot whales than other deep-water areas off Newfoundland (Whitehead and Feyrer unpublished). Multi-year passive acoustic monitoring efforts within the area also demonstrate regular presence of the echolocation (foraging) clicks of these species as well as Cuvier’s beaked whales (Ziphius cavirostris) (Delarue et al. 2024, Feyrer et al. 2024). Minke whales (Balaenoptera a. acutorostrata) and Atlantic white-sided dolphins (Lagenorhynchus acutus) have also been reported within the area (Gomez et al 2020). Data from passive acoustic monitoring also provides evidence for the regular presence of baleen whales in this area, especially fin whales throughout most of the year, blue whales in fall and winter and humpback whales (Megaptera novaeangliae) in winter (Delarue et al. 2022). Sei whales were mainly heard in the autumn (Macklin 2022). There are more occasional sightings of other species such as killer whales (Orcinus orca), common dolphins (Delphinus delphis), bottlenose dolphins (Tursiops truncatus), white-beaked dolphins, (Lagenorhynchus albirostris), and harbour porpoises (Phocoena phocoena) (Gomez et al, 2020).