Southern Labrador Pack Ice Whelping Area IMMA

Criterion A: Species or Population Vulnerability

Two of the Qualifying Species within the Southern Labrador Pack Ice IMMA are considered threatened with extinction according to the IUCN Red List. Polar bears (Ursus maritimus) and hooded seals (Cystophora cristata) are both assessed as Vulnerable (Wig et al 2015, Kovacs 2016).

The polar bear is listed as Threatened under the USA Endangered Species Act and Special Concern by the Committee on the Status of Endangered Species (COSEWIC) in Canada. In 2011 it was formally listed as Special Concern under the Canadian Species at Risk Act. In Newfoundland and Labrador, polar bears are listed as Vulnerable (COSEWIC 2018).

Criterion C: Key Life Cycle Activities

Sub-criterion C1: Reproductive Areas

Harp (Pagophilus groenlandicus) and Hooded seals are endemic to the North Atlantic. With a total abundance of 6.5 million animals (ICES 20231), harp seals are the most abundant marine mammals in the North Atlantic. At approximately 4.7 million animals, Northwest Atlantic harp seals account for 72% of the global population (ICES 2023¹; Tinker et al 2023). Harp seals only haul out on ice to give birth and to rest. Northwest Atlantic harp seals pup on the pack ice off southern Labrador/northeast Newfoundland (referred to as the Front) and in the Gulf of St. Lawrence (Gulf).  This population has been impacted by climate change both directly through increased pup mortality associated with reduced ice, and indirectly through changes in prey availability resulting in increased late-term abortions (Stenson et al 2014; Tinker et al 2023).  Since 1990, the proportion of the NW Atlantic population pupping on the pack ice at the Front has increased from ~80% of total pupping to ~96% in 2017 (69% of the world’s total now pups off Newfoundland), due to a significant reduction of ice in the Gulf (Stenson et al 2022). The southern Gulf component of this population is likely to disappear as seals move to the Labrador area to pup.

The estimated total global abundance of hooded seals is 670,300 animals (ICES 2023, Hammill and Stenson 2006). The Northwest Atlantic population accounts for 89% of the total, but this population has not been assessed since 2006.  The 2006 NE Atlantic hooded seal population estimate was 88,300 animals, much smaller than the abundance estimate for NW Atlantic hooded seals at the time (ICES 2008, Hammill and Stenson 2006). Hooded seals also pup on the southern Labrador pack ice in areas close to the harp seal concentrations. Historically there are two other whelping (i.e. pupping) areas, the southern Gulf of St. Lawrence and in the Davis Strait, but a 2005 survey of all three areas found that>91% of the pups were born off southern Labrador (Stenson et al 2006). Davis Strait pupping had declined since a previous survey and poor ice in the Gulf of St. Lawrence has likely reduced pupping there. As a result, almost the entirety of the NWA hooded seal population now pups in the southern Labrador pack ice area IMMA.

¹ Assuming an adult to pup ratio of 5:1 to estimate Barents Sea harp seal abundance (ICES 2023)

Sub-criterion C2: Feeding Areas

The global abundance of polar bears (Ursus maritimus) is estimated to be 23,300 animals (Hamilton and Derocher 2018). The Davis Strait (DS) population accounts for approximately 9% of the global total or 2200 animals (Hamilton and Derocher 2018; Peacock et al 2013). The southern Labrador pack ice is an important feeding area for polar bears from the DS population. Bears migrate annually from northern Labrador and Baffin Island to the harp and hooded seal whelping concentrations on the southern Labrador pack ice, where they feed intensively during March on the energy-rich harp and hooded seal pups. The energy gained off southern Labrador maintains the bears for much of the year. The proportion of the DS polar bear population migrating south to the harp and hooded seal breeding ice is not known, but increased survival and reproduction of the bears in southern Davis Strait population has been linked to changes in the abundance breeding harp seals in Labrador (Peacock et al 2013).