How will Climate Change affect the Ringed Seal?
The ringed seal is an ice obligate species, meaning it requires ice for hunting, breeding and resting (Moore and Huntington 2008). The loss of this ice due to climate change will be catastrophic for the species abundance (Moore and Huntington 2008). It is predicted that climate change is likely to have four main effects on marine mammals (Moore and Huntington 2008). These include; modification of habitat, alteration of the ecosystem (which will see a reduction in prey numbers), stress to individuals body conditions and an increase in human interaction (Moore and Huntington 2008). The primary, most direct threat to ringed seals is the habitat loss due to melting of sea ice (Moore and Huntington 2008). Unlike other seal species, such as the ribboned and spotted seal, the ringed seal is unable to shift geographically to non-iced areas and as a result is at a much greater risk of extinction (Moore and Huntington 2008). It is predicted that some populations will survive over the short term due to ice refugia, however with the continuing loss of ice, their numbers are expected to decrease rapidly (Moore and Huntington 2008).
Snow depth
The extent and thickness of the ice are crucial factors when determining the ringed seals future as these factors are linked to population size (Moore and Huntington 2008). Snow depth is especially important as a decrease in snow depth below 32cm corresponds to a reduction in ringed seal recruitment (Ferguson 2005).
Subnivian lairs
Warming temperatures will have a significant affect on subnivian breeding lairs (Ferguson 2005)! Warming temperatures, with the addition of body heat exuded, places the roof of the subnivian lair at risk of melting and caving in (Rosing-Asvid 2006 and Stirling and Smith 2004). If this was to occur the pups would visible on the open ice and consequently at a greater risk of predation by polar bears and exposed to climatic conditions making them more susceptible to thermoregulatory stress (Stirling and Smith 2004). In addition warming and rainfall creates a thinned roof allowing polar bears to break through the ice more easily (Ferguson 2005).
Early sea ice break up
In addition to a reduction in sea ice area and depth, the earlier spring ice break up would have a damaging impact on the population of ringed seals as ringed seals exposed to open ocean have an increased risk of predation, encounter thermal challenges, demonstrate less pregnancies and the resulting pups born is lower (Ferguson 2005). Furthermore, early ice break up of breeding area has also been shown to negatively influence growth, condition and survival of nursing pups (Hardwood, Smith and Melling 2000). It is crucial for the seals that a two-month period of solid ice is available for breeding (Meier, Doscher and Halkka 2004). However, with the earlier spring ice break up and later freezing time the period of ice available to the seals is decreasing (Meier, Doscher and Halkka 2004). A study of four populations of Baltic ringed seals undertaken by Meier, Döscher and Halkka (2004) revealed that only one of these four populations would be able to breed most years due to the lack of constant ice over a two-month period.
Snow depth
The extent and thickness of the ice are crucial factors when determining the ringed seals future as these factors are linked to population size (Moore and Huntington 2008). Snow depth is especially important as a decrease in snow depth below 32cm corresponds to a reduction in ringed seal recruitment (Ferguson 2005).
Subnivian lairs
Warming temperatures will have a significant affect on subnivian breeding lairs (Ferguson 2005)! Warming temperatures, with the addition of body heat exuded, places the roof of the subnivian lair at risk of melting and caving in (Rosing-Asvid 2006 and Stirling and Smith 2004). If this was to occur the pups would visible on the open ice and consequently at a greater risk of predation by polar bears and exposed to climatic conditions making them more susceptible to thermoregulatory stress (Stirling and Smith 2004). In addition warming and rainfall creates a thinned roof allowing polar bears to break through the ice more easily (Ferguson 2005).
Early sea ice break up
In addition to a reduction in sea ice area and depth, the earlier spring ice break up would have a damaging impact on the population of ringed seals as ringed seals exposed to open ocean have an increased risk of predation, encounter thermal challenges, demonstrate less pregnancies and the resulting pups born is lower (Ferguson 2005). Furthermore, early ice break up of breeding area has also been shown to negatively influence growth, condition and survival of nursing pups (Hardwood, Smith and Melling 2000). It is crucial for the seals that a two-month period of solid ice is available for breeding (Meier, Doscher and Halkka 2004). However, with the earlier spring ice break up and later freezing time the period of ice available to the seals is decreasing (Meier, Doscher and Halkka 2004). A study of four populations of Baltic ringed seals undertaken by Meier, Döscher and Halkka (2004) revealed that only one of these four populations would be able to breed most years due to the lack of constant ice over a two-month period.