a. Background
The release of petroleum products into the environment, particularly in marine ecosystems, causes significant environmental disasters. Oil spills can result from accidents during oil drilling, pipeline leaks, transportation failures, or illegal practices like bilge dumping. When oil spills into the ocean, it forms a slick on the water’s surface, posing an immediate threat to marine organisms and ecosystems. One of the earliest major oil spills occurred in 1967 when the Torrey Canyon, an oil tanker, ran aground off the coast of Cornwall, England, spilling about 100,000 tons of crude oil into the sea. This was followed by other significant spills, such as the Exxon Valdez spill in 1989 off the coast of Alaska and the Deepwater Horizon catastrophe in the Gulf of Mexico in 2010 (Oil Spill Response, 2023; Zhang et al., 2019).
Oil spills can range from small leaks to large-scale releases, with small spills often occurring during fuel transfers and large spills usually resulting from mechanical failures or accidents. The environmental impact of oil spills is severe. In addition to immediate physical damage, oil can release toxic chemicals into the air and persist in the environment for years, harming wildlife and ecosystems. Humans who rely on marine resources, such as fishermen and those in the tourism industry, are also negatively affected by oil spills (Zhang et al., 2019).
b. Bilge Dumping
Bilge dumping is a significant source of oil pollution in marine environments. It involves discharging bilge water—a mixture of water, oil, chemicals, and other waste materials that accumulate in the lower parts of ships—directly into the ocean. Despite international regulations, such as the MARPOL Convention, which require ships to treat and properly dispose of bilge water, many vessels, particularly older or poorly regulated ones, continue to illegally discharge this waste into the seas (Luis Alfonso Díaz-Secades, 2024). Bilge water contains toxic substances, including oil, heavy metals, and chemicals, which can devastate marine ecosystems. Oil slicks can spread over large areas, disrupting food chains, damaging coral reefs, mangrove swamps, and bioaccumulating toxins in marine organisms, potentially leading to their death.
c. Activity: Simulating Oil Spills and Cleanup Methods
Small-Scale Modeling of Oil Spill Cleanup Methods
Three main methods of clearing an oil spill can be: skimming, absorption, and using dispersants.
- To set up an experiment place a stone in the center of a pie pan and fill it halfway with water.
- Add one tablespoon of dark-colored oil to the water and observe how it spreads.
- Dip a feather into the oily water for 30 seconds, then observe and record how the oil affects the feather.
- Use a spoon to simulate an oil skimmer by gently skimming the oil off the surface without removing water. Record the percentage of oil removed.
- Test the absorbent method by using an absorbent cloth to remove oil and record observations.
- Score the effectiveness and cost of each method using a worksheet (L = Low, M = Medium, H = High).
d. Large-Scale Oil Cleanup Techniques
In large-scale oil spills, more robust cleanup techniques are required. Containment booms—floating barriers used to contain the oil—are commonly employed to prevent the spread of oil slicks. Dispersants, which are chemicals sprayed onto the oil to break it into smaller droplets, can enhance the natural degradation processes. Another method is bioremediation, which involves using oil-degrading bacteria to accelerate the natural breakdown of oil in affected ecosystems.
e. Preventing Oil Spills
Preventing oil spills involves regular inspections and maintenance of offshore drilling rigs and pipelines to identify weak points before they fail. Strict international regulations, such as the MARPOL Convention, help reduce spills caused by human error or illegal dumping. Additionally, training programs for personnel involved in oil extraction and transportation can help minimize human error, a common cause of oil spills.
f. The Future of Oil Spills and Cleanup
As oil exploration moves into deeper and more remote waters, the likelihood of oil spills remains high. However, new technologies are being developed to improve spill detection and cleanup efforts. Drones and autonomous underwater vehicles (AUVs) could play a crucial role in identifying and monitoring oil spills in real time. Additionally, advances in nanotechnology may lead to the development of more efficient oil-absorbing materials, which could significantly improve oil spill response and mitigation efforts in the future.
References
Luis Alfonso Díaz-Secades. (2024). Abatement of bilge dumping: another piece to achieve Maritime Decarbonization. Societal Impacts, 100037–100037. https://doi.org/10.1016/j.socimp.2024.100037
Oil Spill Response. (2023). Torrey Canyon Oil Spill Remembered | 1967 | Oil Spill Response. Oilspillresponse.com. https://www.oilspillresponse.com/news–media/news/remembering-torrey-canyon/
Zhang, B., Matchinski, E. J., Chen, B., Ye, X., Jing, L., & Lee, K. (2019). Marine Oil Spills—Oil Pollution, Sources and Effects. World Seas: An Environmental Evaluation, 3, 391–406. https://doi.org/10.1016/b978-0-12-805052-1.00024-3
