Fun article. It contends scientists "found" an estimated 38 million pieces of plastic. 
For fun consider if "scientists" were to count actual pieces at one per second for twelve hours per day, it would take 2-1/2 years of counting, every day, no holidays, no vacations, to come to that total (no mistakes). So, it's an "estimate" with assumptions, to say the least that can be said about that. There's not even an outhouse on Henderson Island, so that's a rough many years. Most of its shoreline is cliffs, 45 feet high, so, beaches? 
And, if you look the island up on Wikipedia you'll see that same plastic is estimated to weigh 17.6 tonnes, which is 38,801 lbs. Now, a typical semi-rig can carry about that much, so, that plastic is a trailer load, the likes of hundreds that drive by you.
This article is a great one for the amazing scares of environmental catastrophes, the end of life as we know it?
But, now if someone asks you how many toy soldiers fit in a semi (?), you'll know.
Useful?