Habitat Loss from Loud Noise

by Jill Korsiak

As the world continues to develop, the demand for natural resources continues to grow. However, obtaining these needs does not come without a certain level of consequences. Extortion of various natural resources has proven to be quite a difficult and dirty endeavor and persistently leaves an imprint on the surrounding environment. Oil is one such resource which is hugely sought out yet whose extraction process is far from clean. Though there are many environmental regulations that the industry must abide to, the effects are still gravely felt. There have been a myriad of studies conducted that emphasize the increase in pollution due to oil exploration, however one must realize that this is not the only repercussion resulting from the industry. Habitat loss is also a huge consequence, being most detrimental in locations where endangered species subsist. There are obvious and direct reasons for habitat loss, such as the destruction of a forested area to build a factory or a mine, but indirect causes are just as important to consider. One such cause would be noise pollution created by means of explosives, dynamite, machinery, and vehicles, amongst other things. Animals would find these noises to be stressful, hence actively avoiding the location where they are produced.

A group of German researchers from the Max Planck Institute of Evolutionary Anthroplogy recently published a study dealing with this issue. They were curious how intense human-induced noise from oil exploration, most notably through the use of dynamite, effected the spatial distribution of various animals. They set up their experiment in Loango National Park in Gabon, a protected park where numerous large and endangered primates reside. They focused their study on elephants, gorillas, chimpanzees, monkeys, and duikers, actively choosing animals of varying sizes and lifestyles in order to achieve more comprehensive results. In 2006, the Chinese oil company, Sinopec, was granted the right to explore the area in search of oil. This process involved setting off underground explosions and measuring seismic activity in order to discover where exactly the oil is located. The study stresses that this specific exploration is considered rather low impact in comparison to other similar occurrences, as there were many environmental regulations put into place. The researches conducted their study for a period of 6 months: before, during, and after the underground explosions were set off. The presence of the animals were measured through indirect means, most notably through witnessing obvious nests, and feces and through hearing monkey vocalizations. Designated paths were walked by numerous researches a minimum of once a month at various proximities to the sites of explosions. They recorded the effects of the explosions on the habitat of the animals on a large and small scale. The large-scale measurements took into consideration various latitudes and distributions of the animals. They predicted that this would account for the movement of larger, wide-ranging animals that are able to relocate away from the noise. The purpose of the small-scale measurements was to acknowledge the presence of the studied animals in direct relation to the location of the explosions, and determine whether they moved away from the site quickly following an explosion. It was implemented to account for the smaller animals that are less adaptable to habitat change.

As the researches suspected, the size of the animal was closely related to how effected it was by the produced noise. A trend in the large-scale movement of elephants was observed, as they were noticed to continuously migrate away from the seismic activity. They were also affected on the smaller scale because it was noticed that they relocated shortly after an explosion occurred. Both large and small-scale movement of duikers and monkeys was sparsely detected, likely because it is much harder for monkeys and duikers to travel great distances as well as the understanding that they are not as adaptable to habitat change. Furthermore, chimpanzees did leave the immediate location where the explosions took place, yet their large-scale movement was not significant. This is likely because chimps are very territorial and don’t want to infringe on other group’s habitats.

This study has numerous implications. Firstly, we notice that elephants are extremely affected by noise and avoid it the best they can. They lose much of their habitat through the avoidance of deafening sounds, and this implicitly affects their wellbeing and chance of survival. Their lives are put into danger because they are forced out of the protected park and into lands where hunting is permissible. If oil exploration continues, as it likely will, it is essential that animals have a protected refuge where they can subsist undisturbed.

Furthermore, this study ascertains that monkeys and duiker appear rather unaffected by the seismic activity, however one must be wary of this conclusion. The researchers suggest that further studies be conducted to test hormone and stress levels of these animals during the time of oil exploration. Though they may not relocate because of the noises, they may still feel the stresses, which can affect their ability to reproduce and in turn survive. Studying the changes in population of these species over an appropriate period of time would also be a good way to determine the true effects of noise on these animals.

Additionally, it must be noted once again that these effects were noticed on a low impact oil exploration. Much of the time, oil is extracted on a much greater scale with fewer environmental regulations. It is deducible that the consequences would be exemplified, hence greatly disturbing the natural balance of many environments. We can conclude that the oil industry must revolutionize their tactics of extracting oil in order to refrain from causing irreparable harm to the Earth.

Reference:

L.I. Rabanal, H. S. Kuehl, R. Mundry, M.M. Robbins , C. Boesch. Oil prospecting and its impact on large rainforest mammals in Loango National Park, Gabon. Biological Conservation 143 (2010) 1017–1024.