Adam Ingram – Sample Research Writing

Polar Climate Change Effects on the Polar Bear

Polar bears (Ursus maritimus) are astonishing animals that can captivate the youngest of

ages with their snow-white insulating fur and polar climate lifestyle. However, over the past

century the amount of northern sea ice – the polar bear’s main habitat- has dwindled down at an

astonishing rate. This rapid decline of sea ice brings up a serious call to action in order to reduce

the predicted amount of sea ice loss by the year 2030 from climate warming. With this increasing

amount of global sea ice melting the natural organismal and population lifestyle – feeding,

mating, migratory movement- of polar bears has become negatively affected. This fundamental

habitat loss of polar bears is key in the ecological understanding of the adversity affecting polar

predation as well as the polar bear population as a whole. The key to a more exceptional

formulated plan to counteract these effects of climate warming on the Polar Region’s sea ice is to

better understand the patterns of sea ice deterioration and, in turn, its effects on polar bears.

In dealing with decreasing sea ice effects there is a primary concepts that must be

understood about polar bears and it is that polar bears undergo immense physiological strains on

a day to day basis performing tasks such as swimming and trekking for food or protecting their

young (Rode et al., 2012). When hunting for food, one of the polar bear’s main nutritional items

of choice is the harbour seal (Phoca vitulina), which resides primarily just outside the perimeter

of sea ice formations (Bajzak et al. 2013). However, hunting for such prey can leave the polar

bear vulnerable to malnourishment if it does not catch anything for a period of time, especially if

having exuded an enormous amount of energy over the course of its expedition. These everyday

physiological strains also put polar bears in a position where they must be able to consume

copious amounts of food (like the harbour seal) and other nutrients in order to adequately sustain

their regular lives; however, even though polar bears have adapted to their polar climate quite

well by being able to store massive amounts of body fat and reserve fat for times of decreased

feeding and more specifically for the summer months, they are still at a high risk for

malnourishment (Schliebe et al., 2008; Hunter et al., 2010). With the sea ice season decreasing

from nine to seven months over the past thirty years, polar bears have had to exert much more

energy then ever before, in turn, putting greater physiological strain on their bodies (Cherry et

al., 2008; Sahanatien & Derocher, 2011). This greater physiological strain does not go without

consequence. Polar bears are undergoing periods where they are losing abnormally high amounts

of their body mass percentage due to the lack of available proper nutrients in the area (Schliebe

et al., 2008). These periods of immense loss can, in part, be tied back to the extended periods of

time that they are at a high-energy expenditure level, i.e swimming greater distances, longer time

in the water, and farther distances to trek, which is in part due to the decreased amount of sea ice

available to sustain polar bear life (Stirling et al. 1977b; Schliebe et al., 2008; Stirling et al.,

2008a). This may in part stem from the fact that harbour seals tend to stay farther away from the

coast and make longer and deeper dives when sea ice begins to form in the fall and winter

months (usually starting to form in mid September), thus making it more difficult for the summer

ridden-malnourished polar bears to hunt them (Stirling et al. 1977b; Bajzak et al.; 2012, Peacock

et al. 2013).

Another highlighted danger that comes from the factors of harbour seals staying out

farther from shore and polar bears having to make longer swims is the potential for increased

mortality rates of polar bears due to drowning (Monnett and Gleason, 2006; Durner et al. 2011).

In one study, it was shown that a single female polar bear had made an uninterrupted swim of

687km over a 9-day period and then periodically swam and walked for an additional 1,800km,

significantly farther than any polar bear tracked before and also farther than what researchers had

originally theorized even possible for polar bears (Durner et al., 2011). During this prodigious

trek and swim combination, however, the female polar bear lost over 22% of her body mass and

also her yearling cub (Durner et al., 2011). It is speculated that the polar bear was attempting to

aggressively hunt in efforts to feed herself and her cub (Durner et al., 2011). However, this one

case does not stand out as the only irrational behavior observed. Researchers found, during a

time of decreased and broken up sea ice in the Southern Beaufort Sea, an area of cannibalized

and starved to death polar bears as well as holes [ranging from 40-61cm in diameter] that had

been clawed through the ice in a plethora of spots, these behaviors were not observed the

following years (Stirling et al. 2008a). It was concluded by Stirling et. al (2008a) that hunger was

a significant factor of the irrational behaviors observed in the Southern Beaufort Sea, this is

compared to the fact that these behaviors were not observed slightly north in the Northern

Beaufort Sea polar bears that same year where sea ice had not been so broken up at that time of

the year (Stirling et al. 2008a). Irrational behaviors like the ones exhibited here are posing

immediate physiological dangers to polar bears, where they are not able to reach the necessary

nutrition required to sustain habitual and normal living (Stirling et al. 2008a; Regehr et al. 2010;

Durner et al., 2011).

The decreasing sea ice with the physiological strains polar bears undergo daily will soon

become inhibitors to their daily life because of the inability to properly feed and take care of

their young (Schliebe et al., 2008). The reproduction costs for polar bears have already been on

the decline due to over hunting of adult polar bears but as the sea ice decreases more rapidly and

the physiological stressors become inhibitors the reproductive capacity of polar bears will begin

to dwindle down at a much faster rate (Robinson et al. 2011). Polar bear cub mortality rates are

in a wide range from 20-60 percent and a majority of them are of unknown and unobserved

causes (Stirling 1988c; Bix and Lentifer, 1979; Clarkson and Irish 1991; Amstrup and Durner

1995; Kenny and Bickel, 2005; Amstrup et al. 2006; Richardson and Andriashek, 2006;

Robinson et al. 2011). Although there is a wide range of uncertainty about polar bear cub death,

what has been made known is the dead polar bear cubs (n≈5) that had a necropsy performed on

there corpses were determined to have been malnourished and under weight to all other cubs

(n≈128) in the Southern Beaufort Sea that were being tracked and measured during the same

time as these dead cubs (Robinson et al. 2011). This may be attributed to the rapidly declining

area of sea ice and the negative effects it is having on necessary maternal resources, for already

malnourished females, to be collected and/or produced for the cubs which then entails a lack of

adequate feedings for said cubs as well as for the mother, which can lead to a downward cycle of

starvation and then ultimately death (Lee et al., 1991; Oftedal, 1993; Arnould & Ramsay, 1994;

Rode et al. 2010; Robinson et al. 2011).

Another attribution that can be made from the declining area of sea ice is if the fasting

duration for polar bears in the Northern and Southern Beaufort Sea increases from 120 to 180

days the population reproduction pool of able polar bears would significantly decrease (Molnár

et al., 2010). Using a population prediction model from Molnár et al. (2010) for polar bears

where the fasting period was 120 days on average in the 1980s it was shown that only 3% of

non-movement and 6% of moving adult male polar bears died of starvation in a single summer

season; however, using the same projection model with the extended estimate for the fasting

period at 180 days (which is expected to happen before 2030) exhibits signs that 28% of non-

moving and 48% of moving adult males would die of starvation in a single summer season

(Stirling and Parkinson, 2006; Molnár et al., 2010). The sea ice breaking up much earlier in the

spring is preventing the proper nutritional consumption and mass build up for the already

lengthened summer months and thus increasing the fasting periods for polar bears (Molnár et al.

2010). Even though polar bears are only categorized as a threatened species under the

Endangered Species Act, many population projections do not accurately reflect the realistic

effects that climate warming is having on the sea ice inhabitants (ESA; Molnár et al., 2010). The

more immediate and short term effects of decreasing sea ice and lengthened summer seasons

have been more than damaging towards the polar sea ice inhabitants ecology; however, if they

are not soon corrected for the long term effects of the decreasing sea ice will be irreversibly

detrimental to the entire polar climate.

Habitat loss is already occurring to polar wildlife with the seasonal sea ice break up every

year, but it is becoming a more permanent and negatively sustained result year after year. The

consequences of such permanent results range from the relocation and splitting up of animals to

reaching what is known as the critical ice period every year- defined by the amount of days the

sea ice breaks up compared to when it did in 1979 and the duration that the sea ice is melted back

compared to the time it was melted back in 1979 as defined by de la Guardia et al. (2013) in the

western Hudson Bay area –which has been used to model a majority of the polar sea ice habitats

(Sunquist and Sunquist, 2001; Fischer and Lindenmayer, 2007; de la Guardia et al., 2013). A

subsequent issue is that polar bears, along with many other animals, are considered habitat

specific, which ultimately means that they can only thrive and survive in a single habitat (Fischer

and Lindenmayer, 2007). This poses the problem- if the polar bear’s sea ice habitat dwindles

down to where they can no longer carry out the proper ecological lifestyle need to thrive and

survive then the assumption can be made that the population of polar bears will become an

endangered species and may even cease to exist as a species in the wild. A significant relation to

this assumption can be made to how the accelerated rates of sea ice melting are correlated to the

decrease in population growth of polar bears (Regehr et al., 2007; Stirling et al., 2008a). The

declining population growth of polar bears is also negatively effected long term by it being a

species that has seemingly non complex identities- i.e low species diversity, simple

predation/prey exchanges, and a limited interaction capacity due to the artic environment and its

subsequent variables (Regehr et al., 2007; Molnár et al. 2010). These non-complex identities add

substantial weight to the assumption of polar bears ceasing to exist in the wild because of how

intricate they actually are to the survival of the polar bears. The simple predation/prey exchange

identity is the most amenable to the assumption because it is forcing polar bears to spend longer

durations on the shore because of the sea ice decrease (Derocher and Stirling, 1990). This longer

duration makes it difficult for the polar bears to hunt like they normally would on the sea ice and

also makes them a more open target to hunters (Derocher and Stirling, 1990; Sunquist and

Sunquist, 2001). But a possible adaptation that could prove to be helpful to the polar bear habitat

problem is a decrease in overall body mass and size to help counteract the longer onshore stays,

making the polar bear better suited for running and catching prey than swimming, hunting, and

trapping seals (Derocher and Stirling 1990).

If the critical ice period is reached earlier every year and with greater magnitude than

years previous by more than 10% the effect it will have on the polar bear population will be not

only harmful to that years population but have a ripple effect that could last for more than ten

generations (de la Guardia et al., 2013). As well as if the resulting prediction of 28% non-moving

and 48% moving adult males starving to death before the end of the ice-free period becomes

true, then a monumental problem arises because these figures do not include the more sensitive

cubs, sub-adults, females, or females with cubs (Molnár et al. 2010). The critical ice period thus

has a greater impact than that of only affecting a single generation or generations shortly there

after, but possibly the entire future of the polar bear species, which is why sea ice patterns and

degradation must be studied in more detail.

A study conducted on a regularly sized poly-thermal Artic glacier, Pedersenbreen, that

has shown that over seventy-three years (1936-1990-2009) the glacier has decreased over 13%

approximately (AI et al., 2013). The study results concluded that the glacier changes were due to

local climate change and increased summer temperatures (AI et al., 2013). This study and its

conclusions are important because it was a longitudinal study on a specific glacier in the Artic

that can be applied and referenced in similar Artic projects, and allow conclusions to be drawn

on models like that of the critical ice period. Another promising piece with this study is that it

has insurmountable evidence to support local climate change is the largest contributing factor to

the large decrease in area and volume of the glacier (AI et al., 2013) which can also be assumed

to be a contributing factor to the surrounding polar area. The results of this study are also

monumental in helping to predict future patterns of Artic climate change and how over the past

two decades there has been a significant increase in the acceleration of melting of Pedersenbreen

(AI et al., 2013). One of the theories that did come from this study is that some polar researchers

believe that the Artic climate temperature may increase four times the next thirty years compared

to what it did in ninety (Hanssen-Bauer, 2002).

Through the quantitative analysis’ conducted and the various modeling systems used by

the researchers in the past decades leave a conclusive prediction that the sea ice, on which polar

bears use as their habitat, is dwindling down at a significantly compromising rate. This

compromising rate that the polar bears are facing, if not reduced significantly or somehow

reversed will soon leave the polar bears extinct in the wild. The research also shows that multiple

areas of a polar bear’s lifestyle are being put on the line with this decrease in sea ice, which are

in turn, causing a catastrophic ripple effect throughout the polar eco-system; which is also adding

to the possible extinction of the polar bear. However, what must be done to fully and undeniably

back the conclusions drawn are more longitudinal studies on groups of polar bears versus the

study of multiple groups for shorter periods of time, i.e three to five years. The study of sea ice

degradation must also be examined in a long-term fashion, like Pedersenbreen, this will allow for

a supporting conclusive argument that is better rounded around the polar bear and its ecological

lifestyle and habitat. The evidence presented still has much weight to it and is ample in providing

concrete support to the problem of global climate change and its deleterious effect on the polar

region. The global population of mankind must recognize that the global temperature increase is

having a severe and irreversible impact on the Polar Regions ice and its wildlife and that these

impacts will not be able to be undone in the near future if not stopped or significantly reduced

within the next decade.

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