A great green mass roiled in the ocean below. From the hiking trail on a volcanic cliff high above a bay in Hawaii's Waianapanapa State Park, it looked mysterious. Was it an odd collection of surfboards or some exotic ocean creature?

No. It was trash.

By the time I'd wound my way down to the beach near Hana, Maui, an ugly blob — fishing net (the green stuff) entwined with plastic refuse — slumped just offshore. A small army of tourists in flip-flops grabbed it, yanking it to shore with assists from successive waves. This was no easy task since the mass was heavy and had no obvious holds. Once beached, it stretched across nearly the length of black sand.

That's how I got a close-up look at a small piece of the Great Pacific Garbage Patch, or GPGP.

On March 22, one day after my return from Hawaii, the journal Scientific Reports published a paper detailing the GPGP's size. It is now twice as large as Texas and carries a conservative estimate of 79,000 metric tons of plastic. That's the weight of nearly 2,200 humpback whales, a more appropriate occupant of Hawaiian waters. Scientists conducted an aerial survey and captured samples of the debris from boats to produce the report.

As for my surprise encounter, it was proof that paradise is fragile. I was glad I carried a reusable water bottle rather than the disposable type sold in stores across the country, Hawaii included. And I keep thinking of other ways to reduce my use of plastics.

The morning of that hike, I'd visited nearby Hana Bay, where young schoolchildren and their teachers carried garbage bags and fanned out across the sand. I asked one little girl what they were doing.

"Picking up rubbish," she replied matter-of-factly, as she gathered tiny shards of plastic. For locals, it seems, the GPGP (some of which has broken down into small pieces) is no surprise.

Send your questions or tips to Travel Editor Kerri Westenberg at travel@startribune.com, and follow her on Twitter: @kerriwestenberg.