Offshore hydrocarbon exploration and exploitation

Oil and other hydrocarbons are a prized resource. With the looming depletion of global reserves, the rise of prices and international conflicts, it is becoming increasingly profitable to explore the ocean floors in search of new deposits.

Noisy exploration

But oil and gas exploration is no small matter. The seismic surveys involved consist of pummelling the seabed with powerful sound waves. A boat tows an array of compressed air guns. The result is detonations every 10 seconds, 24 hours a day for weeks, even months. These low-frequency and high-intensity sounds are used to survey the geological composition of the seabed and pinpoint areas where hydrocarbons are most likely to be found in exploitable quantities.

These sounds are not confined to the path between the air gun array, the seabed and the boat. They travel hundreds of kilometres, covering territories spanning tens of thousands of square kilometres. According to Chris Clark, director of Cornell University’s (US) Bioacoustics Research Program, seismic exploration is the worst form of noise pollution after acoustic military exercises.

This form of acoustic pollution can have serious impacts on wildlife, especially marine mammals, which depend entirely on sound for every aspect of their lives: communication, finding prey, detecting predators, and navigation. The sounds associated with oil and gas exploration result in behavioural changes that can affect cetaceans’ survival or reproductive success, and can even result in losses of auditory sensitivity, injury or death. These effects are better documented in cetaceans, but studies have shown similar effects in fish and other marine animals.

Risky development

Gas and oil exploration of course open the door to hydrocarbon production, which presents further risks for the marine environment. A single drop of oil can contaminate up to 25 litres of water. The first thing that comes to mind is accidents that can lead to the explosion of a well or the rupture of a pipeline. In many cases, existing response technologies are inadequate to contain and recover spills, leading to serious or even catastrophic ecological damage to the marine environment, like the explosion of the BP Deepwater Horizon drilling platform in April 2010, which resulted in over four million barrels of crude oil being spilt into the Gulf of Mexico. Even in the absence of a spectacular disaster, leaks are commonplace. For example, every year 110 million litres of oil leak from wells, pipelines and other infrastructures of the American oil industry. That’s three times as much as the Exxon Valdez oil spill.

Day-to-day operations also present other hazards. Drilling mud comes to rest on the ocean floors and, even if treated, represents a genuine toxic soup of heavy metals and hydrocarbons. Contaminants also find their way into the ecosystem surrounding oil platforms via air pollution. For example, excess gas is flared off by measure of security, producing hydrocarbon emissions. Additionally, as the platforms are lit at all times, they also present a risk to migratory birds. And, lastly, even the decommissioning of platforms after the source has dried up, presents serious environmental problems. In general, the rules and procedures to follow are insufficient to effectively mitigate environmental risks, with the initiative largely lying with the company.

Conflicts of use

The problems associated with hydrocarbon exploration and production are all the more acute in that these activities conflict with other uses of the sea. From a social perspective, can we justify favouring one activity based on a non-renewable resource when it presents risks for other well established activities like fishing and tourism? These risks are difficult to assess, especially if we attempt to capture the long-term cumulative effects. Further, they often exacerbate other stresses already being sustained by fragile ecosystems depended upon by the economy and way of life of coastal human populations.

What, then, should the future of hydrocarbon development look like? Should we not exercise greater caution, especially in marine environments? Are there more fragile and more “precious” places where this type of activity should even be outlawed? Can’t we strive to achieve higher energy efficiency and develop alternative sources to meet our energy needs? These questions represent genuine challenges for our society, and we need not look any farther for an example than the Gulf and Estuary in our own backyard, which are certainly deserving of the designations “fragile” and “precious”.