(Featured image courtesy Indian Coast Guard and BBC)

When a cargo ship sinks and spills oil into the sea, the headlines often focus on the immediate crisis: the slick on the surface, the smell, and the frantic clean-up efforts. But what happens after the media moves on?

That’s the question facing Kerala today after the Kochi oil spill, where a sunken vessel has raised alarms over the release of furnace oil and hazardous chemicals into the Arabian Sea.

But how long does the sea actually take to recover from such an incident? The answer is far more complex than most people realise.

What happens to oil in the ocean?

When oil spills into seawater, it doesn’t just float on the surface and wait to be cleaned up. It immediately begins to interact with the marine environment, undergoing a series of complex changes:

• Spreading: Within minutes, the oil can fan across several square kilometres, forming a thin, fast-moving slick.
• Evaporation: Lighter compounds in the oil begin to vaporise, especially in warmer tropical climates like the Arabian Sea.
• Emulsification: As the oil mixes with water, it forms a thick, mousse-like substance that’s harder to skim or absorb.
• Sedimentation and sinking: Heavier parts of the oil bind with particles and sink to the seabed, where they can harm marine life long after the surface looks clean.

Think of it like coffee swirling into cream — once mixed in, you can’t just scoop it back out. The oil spreads, sinks, and clings to marine plants, sediments, and even the bodies of fish and birds. It lingers long after the slick disappears from view. This makes oil spills especially dangerous: the most lasting damage is often invisible, happening beneath the surface and within the food chain.

These changes make oil harder to remove and increase the risk of long-term contamination. According to the International Tanker Owners Pollution Federation (ITOPF), ocean recovery can take anywhere from a few months to several decades. The timeline depends on multiple factors, including.

• The type of oil (light vs. heavy)
• The temperature and........
  

  © The Better India