Climate Change and Ringed Seal (Phoca Hispida) Recruitment in Western Hudson Bay

Abstract

Climate warming is predicted to reduce the extent of ice cover in the Arctic and, within the Hudson Bay region, the annual ice may be significantly decreased or entirely lost in the foreseeable future. The ringed seal (Phoca hispida), a key species that depends on sea ice, will likely be among the first marine mammals to show the negative effects of climatic warming. We used 639 ringed seals killed by Inuit hunters from western Hudson Bay (1991–1992, 1999–2001) to assess trends in recruitment relative to snow depth, snowfall, rainfall, temperature in April and May, North Atlantic Oscillation (NAO) from the previous winter, and timing of spring break‐up. Snowfall and ringed seal recruitment varied from lower than average in the 1970s, to higher in 1980s and lower in 1990s. Prior to 1990, seal recruitment appeared to be related to timing of spring ice break‐up which was correlated with the NAO. However, recent 1990–2001 environmental data indicate less snowfall, lower snow depth, and warmer temperatures in April and May when pups are born and nursed. Decreased snow depth, particularly below 32 cm, corresponded with a significant decrease in ringed seal recruitment as indicated by pups born and surviving to adults that were later harvested. Earlier spring break‐up of sea ice together with snow trends suggest continued low pup survival in western Hudson Bay.

Effect of resource subsidies on predator–prey population dynamics: a mathematical model

“…Since arctic foxes must move off the tundra onto the sea ice to exploit the subsidy, our spatial model (IV), in which two distinct habitat patches each contained a different resource for the predator, may better represent this particular biological system. The warming climate and decline in sea ice are already having a negative impact on ringed seals and polar bears [14,47], and our results suggest the loss of this subsidy could destabilize the dynamics of coastal fox and lemming populations, in the sense that arctic fox populations relying on the seal subsidy may be greatly reduced in number, or perhaps even pushed to extinction, due to a decline in the subsidy.…”

Seasonal home ranges and fidelity to breeding sites among ringed seals

“…In recent decades, however, that substrate has been decreasing (Overland and Wang 2007;Serreze et al 2007;Comiso et al 2008), and summer ice may disappear completely within the next 50 years. That reduction in sea ice is expected to negatively impact ringed seal populations (Tynan and DeMaster 1997;Kelly 2001;Smith and Harwood 2001;Stirling and Smith 2004;Ferguson et al 2005;Freitas et al 2008b;Laidre et al 2008;Schmölcke 2008;Cooper et al 2009). …”

“…Better knowledge of the ringed seals' seasonal movements and patterns of habitat use are important for understanding their relationships to (1) polar bears (Ursus maritimus) and other predators, (2) expanding industrial development, and (3) rapid environmental change, especially the decreasing duration of seasonal snow and ice cover (Kelly 1988(Kelly , 2001Tynan and DeMaster 1997;Stirling and Smith 2004;Ferguson et al 2005;Freitas et al 2008b).…”

Influence of sea ice phenology on the movement ecology of ringed seals across their latitudinal range

“…With the continued reduction of sea ice extent, longer ice-free periods and northward expansion of sub-Arctic forage fish species being more punctuated at southerly latitudes (Wisz et al 2015), plasticity in the movement ecology of ringed seals across the Arctic to changing abiotic and biotic factors is paramount to adjust to a rapidly changing climate. However, despite plasticity in the movement ecology of ringed seals, negative consequences of a changing climate on their demography and body condition have been observed at both lower and higher latitudes (Ferguson et al 2005, Harwood et al 2015.…”