Oil spill

What Exactly Is an Oil Spill?

Imagine a vast ocean suddenly turning into a battlefield where nature’s beauty meets human tragedy. An oil spill is precisely that—a release of liquid petroleum hydrocarbon into the environment, usually marine ecosystems, due to human activity.

An oil spill can result from various sources, including tankers, offshore platforms, drilling rigs, and wells. They have severe environmental and economic consequences, affecting animals and plants, and human health, leading to respiratory, reproductive, liver, and immune system problems.

How Do Oil Spills Affect Wildlife?

Oil spills penetrate into the structure of birds’ plumage and mammals’ fur, reducing their insulating ability and making them more vulnerable to temperature fluctuations and buoyancy issues in water. Imagine a fluffy bird or a sleek seal suddenly losing its natural coat—how would it survive?

Birds and Mammals

The immediate negative effects include respiratory and reproductive problems, liver and immune system damage, contamination of drinking water supplies, and economic impact on tourism and marine resource extraction industries. Long-term effects can include the decline of oil supply, potential closure of beaches, parks, fisheries, and fire hazards.

Respiratory and Reproductive Problems

Birds exposed to petroleum experience changes in their hormonal balance, including changes in their luteinizing protein. The majority of birds affected by oil spills die from complications without human intervention. Heavily furred marine mammals are similarly impacted; the ingestion of oil causes dehydration and impairs the digestive process.

What Causes Oil Spills?

Burning surface oil can also generate air pollutants such as soot particles and nitric oxides during cleanup and recovery processes. Bubble bursting can also be a generation pathway for particulate matter during an oil spill. Wetlands are considered one of the most sensitive habitats to oil spills and the most difficult to clean.

Human Error, Natural Disasters, Technical Failures

Oil spills can be caused by human error, natural disasters, technical failures or deliberate releases. It is estimated that 30–50% of all oil spills are directly or indirectly caused by human error, with approximately 20–40% of oil spills being attributed to equipment failure or malfunction.

Natural Seeps and Vessels

Natural seeps account for around 40-50% of all oil released into the oceans, but they are considered less problematic because ecosystems have adapted to such regular releases. Oil spills from vessels account for 21% of oil releases, with operational discharges decreasing by 50% since the 1990s.

Offshore Platforms and Pipelines

Offshore oil platforms account for approximately 3% of oil spills, often resulting from blowouts that can leak enormous amounts of oil over months. As of 2010, there has been a substantial increase in pipeline oil spills over the past four decades.

Cleanup and Recovery

Cleanup and recovery from an oil spill are difficult and depend on various factors, including the type of oil spilled, water temperature, and shoreline conditions. Physical cleanups can be replaced by chemical remediation using compounds that can herd and thicken oil for physical recovery or disperse it in the water.

Bioremediation and Controlled Burning

Methods for cleaning up include bioremediation using microorganisms, bioremediation accelerators, controlled burning, and other technologies. Dispersants can disperse oil slicks by breaking it down into micelles that are diluted rapidly.

Natural Attenuation and Dredging

However, laboratory experiments have shown that dispersants increase toxic hydrocarbon levels in fish and may be toxic to corals. Natural attenuation may be an appropriate method for some cases due to the invasive nature of facilitated methods of remediation.

Prevention Methods

Dredging is used for oils dispersed with detergents and denser than water. Skimming requires calm waters at all times during the process. Solidifying uses dry ice pellets and hydrophobic polymers to change the physical state of oil from liquid to a solid, semi-solid or rubber-like material that floats on water.

Vacuum and Centrifuge

Vacuum and centrifuge involves using a vacuum to suck up oil along with water and then separating the oil from the water using a centrifuge. Beach Raking: coagulated oil on beaches can be picked up by machinery including booms, skimmers, sorbents, chemical and biological agents, vacuums, shovels, and other equipment.

Prevention and Contingency Planning

Prevention methods include secondary containment, Oil Spill Prevention Control and Countermeasures program, double-hulling vessels, thick-hulled railroad transport tanks, and spill response procedures. Research has led to the development of biomimetic oil spill recovery methods inspired by oil bees.

Environmental Sensitivity Index (ESI) Mapping

Imagine a map that can predict where an oil spill might hit hardest—this is what ESI mapping does. It uses shoreline type ranking system, biological resources section, and human-use resource category components to identify sensitive areas.

A Brief History of ESI Mapping

ESI was first applied in 1979 and has been transformed into a versatile online tool since the 1990s. It has made significant advancements in tidal bay protection strategies, collecting seasonal information, and modeling sensitive areas.

Usage and Application

The most common use of ESI maps is in contingency planning, where sensitive areas are identified and protected methods are assessed. The maps are used for drills and trainings to improve cleanup efficiency. ESI categories include shoreline type (ranked on a 10-point scale) and biological resources (including habitats and endangered species).

Estimating the Volume of an Oil Spill

The steps for mapping a shoreline using ESI involve zoning the area, meeting with experts, identifying shore types, biological resources, and human use resources, digitizing the information, and refining it. The most common use of ESI maps is in contingency planning, where sensitive areas are identified and protected methods are assessed.

Volume Estimation

The estimation of the volume of a spill involves observing oil film thickness and surface appearance, calculating total volume with known surface area, using industry and government models that require accurate wind and current field descriptions. Oil spill modeling uses various methods to track scope, including analytical chemistry for fingerprinting an oil source based on hydrocarbons present.

The Largest Oil Spills

Largest oil spills have damaged ecosystems in Alaska, the Gulf of Mexico, Galapagos Islands, France, Sundarbans, Ogoniland, and many other places, with quantities ranging from a few hundred tons to several hundred thousand tons. Between 1956 and 2006, up to 1.5 million tons of oil were spilled in the Niger Delta.

Impact on Wildlife

Oil spills at sea are generally more damaging than those on land, causing harm to seabirds, mammals, shellfish, and other organisms they coat. In contrast, oil spills on land can be contained more easily if a makeshift earth dam is built around the spill site before most of the oil escapes.

Economic Impact

The economic impact of oil spills is devastating, with immediate threats to local and regional economies, lasting impacts on tourism, fishing, and port activity. A decline in tourism follows an oil spill, negatively impacting hotels, restaurants, bars, car park owners, shopkeepers, travel agencies, tour guides, and transport companies.

Case Studies

The U.S. Travel Association estimated $23 billion in associated costs for affected tourist infrastructure following the Deepwater Horizon Oil Spill. The Gulf of Mexico lost an estimated 1.9 billion dollars from fishing revenue due to safety concerns and declining demand. A fishing ban after the Prestige oil tanker spill had severe economic consequences, resulting in expenses of approximately 113 million euros.

Conclusion

The damage caused by oil spills is not just environmental but also economic and social. From the moment an oil slick hits the water to the long-term effects on wildlife and human health, every aspect of our ecosystem can be affected. It’s crucial that we continue to innovate in cleanup methods and prevention strategies to protect our oceans and the life they sustain.