How did the deepest part of the ocean get so polluted
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The Dangers Lurking in the Ocean Depths
For centuries, we’ve been warned of the dangers that lurk deep below the ocean’s surface. Tales of colossal squids, Krakens, and evil villain’s lairs have filled our imaginations. However, the reality is far worse than any mythical creature or secret hideout. The deepest known part of the ocean, the Mariana Trench, which stretches down roughly 36,000 feet, is alarmingly polluted.
The Mariana Trench: A Dumping Ground
Contrary to what one might imagine, the ocean floor at these depths is far from pristine. In fact, it is more polluted than some of the most polluted regions on the surface of the globe. Probes into the Mariana Trench have found physical remnants of actual garbage, such as beer cans, plastic bags, and even an unopened can of SPAM, resting along the Trench’s wall. This trash, unless removed, can stay down there indefinitely, just piling up.
The Problem with Plastics
Plastics, made up of super-strong carbon to carbon bonds, are not prone to being broken down by organic organisms. The material hasn’t existed in nature long enough for there to have evolved much to break it down. In 2016, scientists found one type of microbe that can do it, but only for a specific type of plastic.
Persistent Organic Pollutants
Beyond the physical trash problem, there lies an even deeper issue. A paper published in the journal Nature in late 2016 examined the inhabitants of two of the deepest oceanic trenches in the world. Small crustaceans called amphipods, which store not just fat but also any chemicals that are ingested in their fatty tissue, were found to be contaminated by what are called “persistent organic pollutants” or POPs. These include chemicals that have been banned from use for decades, like polychlorinated biphenyls, which have been shown to be birth defect and cancer-causing. Other chemicals like pesticides were also present.
The Impact of Ocean Pollution
The concentration of POPs was so high that it was 50 times greater than in one of China’s most polluted rivers, and was roughly equal to that of Suruga Bay in Japan, an industrial waste dumping ground. The researchers suggest that the pollution found in the Mariana Trench may be due to the Great Pacific Garbage Patch, a huge floating clump of garbage in the Northwest Pacific ocean. There’s another theory that the pollution found down there is the result of POP chemicals entering the food chain. This pollution is not only harmful to marine life but also to humans as these chemicals eventually reach our own food supply.
The Consequences of Our Actions
Ocean pollution saps the amount of oxygen in the water, leading to mass death of marine life. Certain chemicals can even create reproductive issues for animals in the ocean. Society has spent the last few centuries dumping tons of trash into the ocean, including industrial waste, radioactive waste, munitions, and sewage. The assumption that marine waters had an unlimited capacity to mix and disperse wastes has proven to be false. The out of sight out, of mind approach is killing ocean creatures and endangering our own health. It turns out nowhere is safe from pollution. Not even the deepest part of the ocean.
Discussion Questions
- How does the pollution in the Mariana Trench compare to other polluted regions on the surface of the globe?
- Why are plastics a particularly problematic form of pollution in the ocean?
- What types of chemicals were found in the fatty tissue of the amphipods in the Mariana Trench?
- What are the potential sources of pollution in the Mariana Trench?
- What are the consequences of ocean pollution on marine life?
- How does ocean pollution eventually impact human health?
- Why has the assumption that the ocean can disperse wastes proven to be false?
- What can be done to address the issue of ocean pollution and its impact on marine life and human health?
Lesson Vocabulary
dangers – potential risks or hazards – There are many dangers associated with extreme sports, such as skydiving and rock climbing.
ocean depths – the deepest parts of the sea – The ocean depths are home to a variety of unique and mysterious creatures.
polluted – contaminated or dirty, typically due to harmful substances – The river was highly polluted, making it unsafe for swimming or fishing.
Mariana Trench – the deepest part of the world’s oceans, located in the western Pacific Ocean – The Mariana Trench is known for its extreme depth and fascinating marine life.
dumping ground – a place where waste or unwanted materials are disposed of – The abandoned factory became a dumping ground for toxic chemicals.
plastics – synthetic materials made from polymers, often used for packaging – Single-use plastics, such as water bottles and straws, contribute to environmental pollution.
persistent organic pollutants – toxic chemicals that persist in the environment and can accumulate in living organisms – Certain pesticides and industrial chemicals are classified as persistent organic pollutants.
impact – the effect or influence of something – The construction of a new highway will have a significant impact on the surrounding ecosystem.
consequences – the results or outcomes of an action or event – Failing to address climate change will have severe consequences for future generations.
actions – specific behaviors or steps taken to achieve a goal – It is important to take proactive actions to reduce our carbon footprint and protect the environment.
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- Categories: Science & Technology, TED Ed, Video Lessons
- Keywords: actions, consequences, dangers, dumping ground, impact, Mariana Trench, ocean depths, persistent organic pollutants, plastics, polluted
