A whale death in Spain has finally been explained. Almost a year after the sperm whale washed ashore, marine biologists at the Donana Biological Station have confirmed that the emaciated animal died of starvation, the result of eating so much plastic garbage that its stomach became clogged.
Renaud de Stephanis, a marine biologist at the station, said that the starving whale's stomach held 37 pounds of plastic garbage -- including an entire greenhouse, complete with indoor and outdoor grades of plastic tarp, greenhouse twine and rope, and even a couple of flower pots. He said that the autopsy of the unfortunate sperm whale highlights the importance of keeping plastic garbage out of the world's oceans.
The cause of whale deaths isn't always so clear cut. There have been a number of sightings where apparently healthy whales washed up or even swam up on beaches for no immediately obvious reason. In October, 40 pilot whales were found dead on the Andaman coast of India. In those deaths, scientists blamed a low-frequency sonar that was being used by the Indian military to locate submarines, stating the sonar was actually loud enough to damage the endangered animals' brains.
The Natural Resources Defense Council (NRDC), an advocacy group for endangered animals, has also implicated the use of US military sonar in whale deaths. The resulting sound can blast more than 235 decibels into the ocean when hunting for enemy submarines. "By the Navy's own estimates, even 300 miles from the source, these sonic waves can retain an intensity of 140 decibels -- a hundred times more intense than the level known to alter the behavior of large whales," they said.
Now there is evidence that our careless disposal of plastic trash, not just noisy military maneuvers, must also take some of the blame.
Some garbage is blown into the sea as a result of natural disasters like Superstorm Sandy or the Japanese tsunami. In fact, the tsunami case is particularly instructive,because the disaster happened almost two years ago and yet debris is still making the 8,000 kilometer trek from Japan to the west coast of North America where objects weighing over 100 tons are still washing up.
However, the National Oceanic and Atmospheric Administration (NOAA) said that most sea garbage is plastic, probably because plastic floats, so it continues to circulate in the sea until it's removed or eaten. Turtles, sea lions, pelagic birds, and dolphins as well as whales have been documented to eat and die from the plastic they encounter in the ocean.
Last September, Delhi, the capital of India, banned plastic bags except when needed for the safe disposal of medical waste.
Maybe if we all cut back on using plastic bags, we can also cut down on tragic whale deaths.