Impact
of Oil Exploration and Drilling on ANWR Predators
|
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). 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. 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 |
costiner"at"mit.edu
Last updated: Nov. 13,
03