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What are the impacts of oil exploration and drilling
on ANWR predators?
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Introduction
It is widely known
that animals are very sensitive to their surroundings and are affected by
changes produced in their environment. In the case of oil exploration, these
disturbances are created by noise, “generated by seismic exploration,” or
are a result of “routine industrial activities, vehicle and aircraft traffic,
and disturbance of dens” (1, p.98). Evidence of how animals’ lifestyle and
behavior patterns are affected by human intrusion in their habitat and oil
development can be gathered from Prudhoe Bay, a Northern Alaskan area that
has been exposed to drilling. This place has a fauna that is similar to that
of the Arctic National Wildlife Refuge (ANWR) and especially the 1002 area
that is susceptible to drilling. Therefore the change in the animals behavior
patterns will be analyzed using information gathered from this area, as this
is a good estimate of how animals will behave in the almost similar environment
of ANWR when exposed to changes caused by oil drilling.
Bears
Polar
Bears
ANWR is an important place
not only because of the wide variety of species that it shelters but also
because this “coastal tundra is America’s only land denning habitat for polar
bears” (2). Over the past two decades the polar bear population has been steadily
increasing, growing at more than 3% per year from 1967 to 1998, to reach
an estimated number that could be as high as 2500 animals in 2001 (3). This
rapid population growth of this species has “spanned the entire history of
petroleum development in arctic Alaska” (3) as the polar bear population is
thriving and thus will not likely be decimated even if drilling is to negatively
affect the bears. In fact in a study (Amstrup and Durner) conducted
in 1995, 85% of documented deaths of adult female polar bears were a result
of hunting and not of environmental changes or natural factors. Although polar
bear population is nearing “historic heights” caution must be taken as “possible
changes in human activities, including hunting and habitat alterations could
precipitate further declines” (3). This point will be clarified in the next
section that discusses bears in general (of which polar bears are a part).
Yet, according to WWF report on ANWR, polar bears
are especially sensitive to disturbance during denning. The Agreement on
the Conservation of Polar Bears committed the arctic nations to "protect
the ecosystems of which polar bears are a part, with special attention to
habitat components such as denning and feeding sites and migration patterns.”
Females may abandon their dens if disturbed, and early den abandonment may
be fatal to cubs unable to fend for themselves. In 1985, a female polar bear
abandoned her maternity den in the Arctic Refuge coastal plain after seismic
exploration vehicles tracked within 700 feet of it – even though regulations
at the time required a 0.8-kilometer buffer from known dens. This occurred
despite the most extensive monitoring program ever in place for seismic exploration
on the North Slope. Most maternity den sites are never known, and therefore
cannot be avoided. Their natural curiosity and keen sense of smell often
places polar bears in harm’s way – they can be attracted to drill rigs, garbage
dumps, and contaminants. Polar bears are especially sensitive to oil spills
because they search for food in the open leads or broken ice where oil accumulates.
Interactions between polar bears and humans are often lethal. A young bear
was shot in Prudhoe Bay by an oil industry employee during the winter of
1968-69, and in 1990 a bear was killed when it approached an offshore rig
in Camden Bay, off the Refuge. (WWF's paper titled "Protection of the
Artic National Wildlife Refuge: Key to Managing one of the World's Most Biologically
Valuable Ecoregions, the Arctic Coastal Tundra")
All
Bear Species (especially brown and black bears)
Land mammals that are “most likely to interact
with or be affected by the proposed operations (drilling) are river otters,
black bears,and brown bears” (4). Brown bears use the coastal areas from
April to November, relying especially on coastal meadows, beaches, and shorelines
for food (4). As they feed on salmon, and other fish, uncontaminated water
sources are essential to their survival, especially during summer and early
fall when brown bears “congregate along coastal streams” (4). Therefore
chemical runoff of drilling released in streams would affect the bear population.
Also, if ice roads are to be build, and these depleting the water supply would
decrease the fish population in rivers, the bears would be additionally affected.
In the case of Prudhoe
Bay, it has been observed that bears are attracted to the pipelines and oil
developments by seer curiosity,food odors, or trash (4, pg. 118). These bears
become food conditioned and return to these places. If this happens often
enough, and this event threatens human security, these bears have to be shot.
In fact in a study of Prudhoe Bay oilfields (Shideler and Hechtel 2000) ,
it was found that “mortality rates of all adults and subadults that fed on
anthropogenic [of human origin] foods was significantly higher than for
bears that fed on natural foods” (4, pg. 118). This finding
could be related to the toxicity of human wastes or to the fact that these
bears had to be killed by humans, as was before mentioned, because food conditioning occurred. Additionally, it is possible that in the future,
“increased access opportunities (roads and airstrips) and changes in village
lifestyles or economies could result in more bears being killed for sport
and subsistence” (4) especially as these animals are attracted to human settlements.
Another area of concern
is the “construction of industrial facilities [that would] result in alteration
or destruction of grizzly bear habitat” (4). This especially concerns disturbances
created by roads or drilling that can affect the denning habitat of bears, and change food availability. This is especially
dangerous if oil development is to spread into the
foothills, as these provide the major habitats of bears. (4)
It also must be taken into
account that bears are the predators that top the food chain, implying that
any change in their dynamics would also affect that of other organisms residing
in the lower branches of the food chain. For example, if bear population
is to increase because of increase access to food coming from human wastes,
or if it is to decrease as hunting prevails, this will affect other species.
The major species affected by this change in bear population would be the
caribou, the main food source of brown, and black bears. Increased numbers
of bears would decrease the number of caribou present, and likewise, a decreased
number of these predators would probably allow for an increase in the number
of these herbivores.
Arctic
Foxes
From recent studies it
has been seen that, “past and current industrial activities on the North Slope
have probably increased the availability of shelter and food for the arctic
fox” (4, pg. 117). Like bears, these animals too use oil fields for foraging
on garbage, or resting. Foraging of these sites is more likely to occur
in the winter when food is more scare than in the summer. It has been observed
that “foxes do not avoid human activity” (4) raising their young in the proximity
of traveled roads and operating drill rigs. Over the years it is remarked
that, “the density and the rate of occupancy of dens and the sizes of litters
are greater in oil fields than in adjacent areas” (4). These increasing
fox numbers have a negative impact on bird population, which are extensively
hunted by these. This can be especially “devastating to colonial birds” or
to birds that migrate to the area (4). An increase number of roads, has also
allowed foxes to access other bird populations that were before inaccessible to them. Thus,
it has been seen that oil exploration in the Alaskan region increases fox
population which has an adverse effect on other species, such as birds.
Wolves
Wolves primarily den in the foothills and mountains
south of the coastal plain in the refuge. Wolverines are infrequently observed
but travel in all types of arctic terrain, and females may use snowdrifts
along small tundra streams for dens. During spring, wolves roam out to the
coastal tundra where they prey on newborn caribou. Population declines or
changes in distribution of wolves are results PREDICTED from the increased
mortality, decreased prey, harrassment, and disturbance in denning areas
caused by oil development. The cumulative effects of displacement, avoidance,
and reduced food resourses could result in long-term changes in wolverine
distribution. Further information found here.
Works Cited
1. Cumulative
Environmental Effects of Oil and Gas activities on Alaska’s
North Slope
www.nap/edu/openbook/0309087376/html
2. Save Alaska
website
www.savealaska.com/sa_anwr.html
3. Arctic Refuge Coastal Plain Terrestrial
Wildlife Research Summaries,
Section 8: Polar Bear
http://www.absc.usgs.gov/1002/section8.htms
4. Environmental Assesment, Redouct Shoal
Unit Development Project, section 3.8.3 .
http://yosemite.epa.gov/R10/water.nsf/0/9316eb066fa30af088256b4b000a77e6/
$FILE/Forest%20Oil%20EA%20Section%2003A%20Affected%20(Baseline)%20Environment.pdf
5. WWF's
paper titled "Protection of the Artic National Wildlife Refuge: Key to
Managing one of the World's Most Biologically Valuable Ecoregions, the Arctic
Coastal Tundra"
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By Lia Costiner
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