Search and rescue teams have been struggling to find the remains of Malaysian Airlines Flight 370 since it disappeared on March 8. But in their intense scrutiny over thousands of square miles of the South Indian Ocean, they have found considerable amounts of man-made trash unrelated to that ill-fated airliner.

Though the apparent loss of 239 lives on Flight 370 was a sudden large-scale tragedy, the intensifying environmental degradation of the world's oceans is a colossal long-term calamity.

As journalist Marc Lallanilla wrote Monday on livescience.com: "In addition to foul weather, administrative bungling and the vastness of the search area, the search for MH 370 has been compounded by one other factor: the incredible amount of garbage already floating in the search area - and in oceans worldwide."

Searchers have repeatedly mistaken such refuse for what's left of that Boeing 777, which took off from Kuala Lampur, Malaysia, bound for Beijing.

And though there are more than 332 million cubic miles of water in the world's oceans, that's still not enough to hide the rising tide of rubbish our kind has been discarding in them.

As The Associated Press reported this week, there is now a vast patch of ocean "between Hawaii and California known as the Great Pacific Garbage Patch, which by some accounts is about the size of Texas."

Oceanographer Charles Moore told the AP: "The ocean is like a plastic soup, bulked up with the croutons of these larger items. It's like a toilet bowl that swirls but doesn't flush."

The story added: "The larger items tend to be plastic and are often fishing-related, Moore said. Though, he added, he has come across light bulbs, a toilet seat, and, bobbing off the California coast, a refrigerator, complete with defrosted orange juice."

And a group of scientists recently told USA Today that growing volumes of debris from the devastating March 2011 tsunami that hit Japan and swamped a nuclear plant will soon reach the U.S. West Coast. Though those experts say the objects' levels of radiation are probably not high enough to pose a threat to humans, that story's another reminder of our species' ultimately mutual environmental risks.

Yes, the South Indian Ocean and even California are a long way from our S.C. coast. Yet the daunting implications of oceans serving as dumping grounds should be all too clear here.

Certainly the annual large haul of aquatic litter in the S.C. Beach and River sweeps already has shown how much people have been trashing our state's relatively pristine coast, rivers, lakes and creeks.

Humanity shares the world's waters, just as we share its land and air.

And if we don't take care to preserve the ecological health of all three, we will also share grim consequences.