Eastern Scotian Slope Canyons IMMA
Size in Square Kilometres
8 944 km2
Qualifying Species and Criteria
Sei Whale – Balaenoptera borealis
Criterion A; Criterion B (2)
Blue Whale – Balaenoptera musculus
Criterion A; Criterion B (2); Criterion C (2)
Fin Whale – Balaenoptera physalus
Criterion A; Criterion B (2)
Long-finned Pilot Whale – Globicephala melas
Criterion B (2)
Northern Bottlenose Whale – Hyperoodon ampullatus
Criterion B (1, 2); Criterion D (1)
Atlantic White-sided Dolphin – Lagenorhynchus acutus
Criterion B (2)
Humpback Whale – Megaptera novaeangliae
Criterion B (2)
Sowerby’s Beaked Whale – Mesoplodon bidens
Criterion B (2); Criterion C (2)
Sperm Whale – Physeter macrocephalus
Criterion A; Criterion B (2); Criterion C (2)
Cuvier’s Beaked Whale – Ziphius cavirostris
Criterion C (2)
Marine Mammal Diversity
Balaenoptera borealis, Balaenoptera musculus, Balaenoptera physalus, Globicephala melas, Hyperoodon ampullatus, Lagenorhynchus acutus, Megaptera novaeangliae, Mesoplodon bidens ,Physeter macrocephalus, Stenella coeruleoalba, Delphinus delphis, Ziphius cavirostris
Download fact sheet
Summary
The Eastern Scotian Slope Canyons IMMA is located along the continental slope southeast of Nova Scotia. The area spans roughly 120 km along the Scotian Slope, and up to about 110 km perpendicular to the shelf. It includes three large submarine canyons, the Gully, Shortland Canyon and Haldimand, as well as inter-canyon areas spanning depths from 200 m to 3,200 m. This area encompasses the core breeding grounds and feeding areas of the small resident Scotian Shelf population of northern bottlenose whales (Hyperoodon ampullatus). The IMMA also serves as a feeding area for blue whales (Balaenoptera musculus) and sperm whales (Physeter macrocephalus), and sustains a high diversity of marine mammals (at least 13 species). Within this area are endangered blue whales and sei whales (Balaenoptera borealis), as well as vulnerable fin (Balaenoptera physalus) and sperm whales. The area includes the Gully Marine Protected Area, which provides good protection for marine mammals, as well as parts of the Eastern Canyons Marine Refuge, which protects the seafloor.
Description of Qualifying Criteria
Criterion A – Species or Population Vulnerability
Four of the species that regularly occur in this area and qualify for other criteria in this IMMA are considered threatened with extinction according to the global IUCN Red List. The blue whale (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; Cooke 2018c) and sperm whale (Physeter macrocephalus; IUCN 2019) are both listed as Vulnerable on the Red List globally.
Additionally, the Canadian Species at Risk Act (SARA – the Canadian legislation for protection of at-risk species) lists the Scotian Shelf population of northern bottlenose whales (Hyperoodon ampullatus) as Endangered (DFO 2016).
Criterion B: Distribution and Abundance
Sub-criterion B1 – Small and Resident Populations
While multiple populations of northern bottlenose whales occur in the North Atlantic Ocean, the Scotian Shelf population is a very small resident population occurring at the extreme southern limit of the species’ range. The Eastern Scotian Slope Canyons area encompasses the core important habitat of this population, which is resident in the area throughout the year, with some photo-identified individual animals showing high levels of long-term site fidelity over 30 years (Wimmer and Whitehead 2005; Feyrer et al. 2021). Passive acoustic monitoring detections recorded the presence of northern bottlenose whales in the Gully submarine canyon on all recording days, and show regular northern bottlenose whale foraging within and between these canyons (Stanistreet et al. 2021, Feyrer et al. 2024). Mark-recapture analyses using photo-identification, which include heterogeneity in identification, estimate that the population numbers about 143 animals (95% CI: 129 to 156 animals; O’Brien and Whitehead 2013), although a more recent unpublished analysis indicates that in 2023 it had risen to about 210 (95% CI: 150 to 287; Feyrer et al. in prep.). These animals are genetically distinct from other populations in the North Atlantic (Feyrer et al. 2019).
Sub-criterion B2: Aggregations
Sighting rates during surveys run from 10-12m research sailing vessels between 1988-2023 from June to early September indicate that the number of groups observed per hour equivalent in excellent conditions were considerably higher in the canyons (2962 hours effort) than other areas along the edge of the Scotian Shelf (417 hours effort) for the following species: blue whales (0.029 vs 0.014); fin whales (0.030 vs 0.014); pilot whales (Globicephala melas; 0.170 vs 0.105); northern bottlenose whales (0.601 vs 0.012); Atlantic white-sided dolphins (Lagenorhynchus acutus; 0.117 vs 0.041); humpback whales (Megaptera novaeangliae; 0.014 vs 0.007); and Sowerby’s beaked whales (Mesoplodon bidens; 0.085 vs 0.010) (Whitehead and Feyrer in preparation). Additionally, sperm whales (for which data could not be used for these sighting rates) were acoustically detected at about 30% of listening stations in the canyon areas, and “occasionally” (ca. 10% of listenings) in other parts of the Scotian Shelf (Whitehead et al. 1992). Longer term passive acoustic monitoring efforts using bottom-mounted recorders deployed for months to years at a time also indicate regular presence of multiple beaked and baleen whales (see Criterion D2), including the presence of northern bottlenose whales in the Gully submarine canyon on 100% of recording days (Stanistreet et al. 2021, Feyrer et al. 2024), and sei whales (Balaenoptera borealis) on about 50-75% of recording days during the summer months (Macklin 2022). The enhanced densities in the canyons are likely a result of increased prey densities caused by unusual oceanographic processes, especially in the largest canyon, the Gully (Moors-Murphy 2014).
Criterion C: Key Life Cycle Activities
Sub-criterion C2: Feeding Areas
Foraging within the Gully and inter-canyon areas by Sowerby’s and Cuvier’s (Ziphius cavirostris) beaked whales is evidenced by recordings of their deep-water echolocation clicks during passive acoustic monitoring studies (Stanistreet et al. 2017, Delarue et al. 2024, Feyrer et al. 2024). Similarly, sperm whale echolocation clicks commonly recorded in the area are almost certainly linked to benthic foraging on species such as monkfish (Lophius americanus) (Mullins et al. 1988; Whitehead et al. 1992). Blue whales have been observed engaged in feeding behaviour in the canyons, presumably because the canyon-dependent oceanographic processes aggregate zooplankton in sufficient quantities. Furthermore the eastern Scotian Shelf canyons and inter-canyon areas have been identified as part of important blue whale feeding habitat (DFO 2018, Lesage et al. 2018) which is supported by krill modelling studies (Plourde et al. 2016) as well as visual observations and acoustic detections (Moors-Murphy et al. 2019).
Criterion D: Special Attributes
Sub-criterion D1: Distinctiveness
Movement models suggest that about 40% of the Scotian Shelf northern bottlenose whale population uses the Gully during any 5-day period (Feyrer et al. in prep.), with substantial numbers in Shortland Canyon, Haldimand canyon, and other parts of the IMMA at any time (Wimmer and Whitehead 2005, Stanistreet et al. 2021). The IMMA is at the extreme southern limit of the species’ usual range (Whitehead and Hooker 2012), and the Scotian Shelf population is genetically distinct from other populations in the North Atlantic (Feyrer et al. 2019).
Sub-criterion D2: Diversity
High species diversity within this area generally, and specifically within the Gully submarine canyon, has long been documented (Hooker et al. 1999, Whitehead 2013). During surveys between June and early September from 1988-2023 using 10-12 m research sailing vessels (3537 equivalent hours in excellent sighting conditions), ten species are represented by 50 or more group sightings: blue whales, common dolphins (Delphinus delphis), fin whales, humpback whales, northern bottlenose whales, pilot whales, Sowerby’s beaked whales, sperm whales, striped dolphins (Stenella coeruleoalba) and white-sided dolphins (Whitehead and Feyrer in prep.). This large species diversity in the area is also supported by long-term passive acoustic monitoring studies that provide evidence of the regular presence of beaked whales throughout the year, including northern bottlenose whales, Sowerby’s beaked whales, and Cuvier’s beaked whales (Stanistreet et al. 2017, 2021, Delarue et al. 2024, Feyrer et al. 2024); as well as the seasonal occurrence of baleen whales including blue, fin, sei and humpback whales (Kowarski et al. 2017, Moors-Murphy et al. 2019, Davis et al. 2020, Delarue et al. 2022, Macklin 2022, Wingfield et al. 2022). Thus, at least 13 species use the IMMA on a regular basis.
Supporting Information
Cooke, J.G. 2018a. Balaenoptera musculus (errata version published in 2019). The IUCN Red List of Threatened Species 2018: e.T2477A156923585. https://dx.doi.org/10.2305/IUCN.UK.2018-2.RLTS.T2477A156923585.en. Accessed on 29 March 2024.
Cooke, J.G. 2018b. Balaenoptera borealis. The IUCN Red List of Threatened Species 2018: e.T2475A130482064. https://dx.doi.org/10.2305/IUCN.UK.2018-2.RLTS.T2475A130482064.en. Accessed on 17 April 2024.
Cooke, J.G. 2018c. Balaenoptera physalus. The IUCN Red List of Threatened Species 2018: e.T2478A50349982. https://dx.doi.org/10.2305/IUCN.UK.2018-2.RLTS.T2478A50349982.en. Accessed on 29 March 2024.
Davis, G. E., Baumgartner, M. F., Corkeron, P. J., Bell, J., Berchok, C., Bonnell, J. M., Thornton, J. B., Brault, S., Buchanan, G. A., Cholewiak, D. M., Clark, C. W., Delarue, J., Hatch, L. T., Klinck, H., Kraus, S. D., Martin, B., Mellinger, D. K., Moors-Murphy, H., Nieukirk, S., Nowacek, D. P., Parks, S. E., Parry, D., Pegg, N., Read, A. J., Rice, A. N., Risch, D., Scott, A., Soldevilla, M. S., Stafford, K. M., Stanistreet, J. E., Summers, E., Todd, S., and Van Parijs, S. M. 2020. Exploring movement patterns and changing distributions of baleen whales in the western North Atlantic using a decade of passive acoustic data. Global Change Biology, 1-30.
Delarue, J.J.-Y., Moors-Murphy, H., Kowarski, K.A., Davis, G.E., Urazghildiiev, I.R., and Martin, B. 2022. Acoustic occurrence of baleen whales, particularly blue, fin, and humpback whales, off eastern Canada, 2015–2017. Endangered Species Research. 47: 265-289. DOI: 0.3354/esr01176.
Delarue, J.-Y., Moors-Murphy, H.B., Kowarski, K. A., Maxner, E.E., Davis, G.E., Martin, S.B., Stanistreet, J.E. 2024. Acoustic occurrence of beaked whales, off eastern Canada, 2015–2017. Endangered Species Research. 53: 439-466. DOI: 10.3354/esr01314.
DFO. 2016. Recovery Strategy for the Northern Bottlenose Whale, (Hyperoodan ampullatus), Scotian Shelf population, in Atlantic Canadian Waters [Final]. Species at Risk Act Recovery Strategy Series. Fisheries and Oceans Canada, Ottawa. vii + 70 pp.
DFO. 2017. Management Plan for the Sowerby’s Beaked Whale (Mesoplodon bidens) in Canada. Species at Risk Act Management Plan Series. Fisheries and Oceans Canada, Ottawa. Iv + 46 pp.
DFO. 2018. Identification of habitats important to the blue whale in the western North Atlantic. DFO Can. Sci. Advis. Sec. Sci. Advis. Rep. 2018/003.
Feyrer, L.J., Bentzen, P., Whitehead, H., Paterson, I.G. and Einfeldt, A., 2019. Evolutionary impacts differ between two exploited populations of northern bottlenose whale (Hyperoodon ampullatus). Ecology and evolution, 9(23), pp.13567-13584.
Feyrer, L. J., Stewart, M., Yeung, J., Soulier, C., and Whitehead, H. 2021. Origin and persistence of markings in a long-term photo-identification dataset reveal the threat of entanglement for endangered northern bottlenose whales (Hyperoodon ampullatus). Frontiers in Marine Science. 8. https://doi.org/10.3389/fmars.2021.620804
Feyrer, L.J., Stanistreet, J.E., Gomez, C., Adams, M., Lawson, J.W., Ferguson, S.H., Heaslip, S.G., Lefort, K.J., Davidson, E., Hussey, N.E. and Whitehead, H., 2024. Identifying important habitat for northern bottlenose and Sowerby’s beaked whales in the western North Atlantic. Aquatic Conservation: Marine and Freshwater Ecosystems, 34: e4064.
Hooker, S.K., Whitehead, H., and Gowans, S. 1999. Marine Protected Area design and the spatial and temporal distribution of cetaceans in a submarine canyon. Conservation Biology. 13 (3): 592-602.
International Union for Conservation of Nature (IUCN) 2019. Physeter macrocephalus. The IUCN Red List of Threatened Species. Version 2024-1 International Union for Conservation of Nature (IUCN) 2019. Physeter macrocephalus. The IUCN Red List of Threatened Species. Version 2024-1
Kowarski, K., Evers, C., Moors-Murphy, H.B., Martin, B. and Denes, S.L. 2017. Singing through winter nights: The seasonal and diel occurrence of humpback whale calls in and around the Gully MPA, offshore eastern Canada. Canadian Journal of Zoology. 34:169-189.
Lesage, V., Gosselin, J.-F., Lawson, J.W., McQuinn, I., Moors-Murphy, H., Plourde, S., Sears, R., Simard, Y. 2018. Habitats important to blue whales (Balaenoptera musculus) in the western North Atlantic. DFO Can. Sci. Advis. Sec. Res. Doc. 2016/080: iv + 50 p.
Macklin, G. 2022. Spatiotemporal patterns in acoustic presence of sei whales (Balaenoptera borealis) in Atlantic Canada. MSc Thesis, Dalhousie University. 125 pp. Available online: https://dalspace.library.dal.ca/handle/10222/81559?show=full
Moors-Murphy, H.B., 2014. Submarine canyons as important habitat for cetaceans, with special reference to the Gully: a review. Deep Sea Research Part II 104, pp.6-19.
Moors-Murphy, H.B., Lawson, J.W., Rubin, B., Marotte, E., Renaud, G., and Fuentes-Yaco, C. 2019. Occurrence of Blue Whales (Balaenoptera musculus) off Nova Scotia, Newfoundland, and Labrador. DFO Can. Sci. Advis. Sec. Res. Doc. 2018/007. iv + 55 p.
Mullins, J., Whitehead, H., and Weilgart, L. S. 1988. Behaviour and vocalizations of two single sperm whales, Physeter macrocephalus off Nova Scotia. Canadian Journal of Fisheries and Aquatic Sciences, 45: 1736-1 743.
O’Brien, K. and Whitehead, H., 2013. Population analysis of Endangered northern bottlenose whales on the Scotian Shelf seven years after the establishment of a Marine Protected Area. Endangered Species Research, 21(3): 273-284.
Plourde, S., Lehoux, C., McQuinn, I.H., and Lesage, V. 2016. Describing krill distribution in the western North Atlantic using statistical habitat models. DFO Can. Sci. Advis. Sec. Res. Doc. 2016/111. V + 34 p.
Stanistreet, J.E., Nowacek, D.P., Baumann-Pickering, S., Bell, J.T., Cholewiak, D.M., Hildebrand, J.A. et al. 2017. Using passive acoustic monitoring to document the distribution of beaked whale species in the western North Atlantic Ocean. Canadian Journal of Fisheries and Aquatic Sciences, 74: 2098–2109. https://doi.org/10.1139/cjfas-2016-0503
Stanistreet, J. E., Feyrer, L. J., & Moors-Murphy, H. B. 2021. Distribution, movements, and habitat use of northern bottlenose whales (Hyperoodon ampullatus) on the Scotian Shelf. DFO Can. Sci. Advis. Sec. Res. Doc. 2021/074; p. vi + 34 p. https://publications.gc.ca/collections/collection_2022/mpo-dfo/fs70-5/Fs70-5-2021-074-eng.pdf
Whitehead, H. 2013. Trends in cetacean abundance in the Gully submarine canyon, 1988– 2011, highlight a 21% per year increase in Sowerby’s beaked whales (Mesoplodon bidens). Canadian Journal of Zoology 91: 141– 148.
Whitehead, H., Brennan, S. and Grover, D., 1992. Distribution and behaviour of male sperm whales on the Scotian Shelf, Canada. Canadian Journal of Zoology, 70(5), 912-918.
Whitehead, H. and Hooker. S.K., 2012. Uncertain status of the northern bottlenose whale (Hyperoodon ampullatus): population fragmentation, legacy of whaling, and current threats. Endangered Species Research 19: 47-61.
Wimmer, T. and Whitehead, H., 2005. Movements and distribution of northern bottlenose whales, Hyperoodon ampullatus, on the Scotian Slope and in adjacent waters. Canadian Journal of Zoology, 82(11), 1782-1794.
Wingfield, J.E., Rubin, B., Xu, J., Stanistreet, J.E., and Moors-Murphy, H.B. 2022. Annual, seasonal, and diel patterns in blue whale (Balaenoptera musculus) call occurrence off eastern Canada., Endangered Species Research. 49: 71-86. DOI: 10.3354/esr01204.
Downloads
Download the full account of the Eastern Scotian Slope Canyons IMMA using the Fact Sheet button below:
To make a request to download the GIS Layer (shapefile) for the Eastern Scotian Slope Canyons IMMA please complete the following Contact Form:
