Story highlights The Sanchi sank Sunday after days engulfed in flames

Much of the oil may have evaporated, but what's left could impact marine life

(CNN) A massive oil tanker that sank off the coast of China could affect marine life for decades, environmentalists and experts say.

The Iranian-owned Sanchi fell to the ocean floor Sunday , eight days after it collided with a Hong Kong-registered cargo ship, resulting in a toxic, fiery blaze that claimed the lives of 32 crew members.

China's State Oceanic Administration said several oil slicks have already been found, including one nearly 15 kilometers long (9.3 miles) and another covering an area of 58 square kilometers (22.4 square miles).

The 900 foot-long tanker was carrying 136,000 tons -- around 1 million barrels -- of ultra-light crude oil at the time of the collision. Environmentalists and officials are worried the oil on board and the fuel used to power the massive vessel could harm nearby aquatic life.

"The critical thing is to understand that when we put hydrocarbons into the oceans through events like this, it's going to affect a wide range of animals," said Jessica Meeuwig, a professor of biological sciences at the University of Western Australia.

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