The Ocean Cleanup led a survey of the Great Pacific Garbage Patch using 30 vessels and aerial imagery to measure how much plastic is there and what it is made of.
They estimated at least 79,000 tonnes (range 45,000–129,000 tonnes) of plastic in an area of 1.6 million square kilometres, made up of about 1.8 trillion pieces. Fishing nets made up at least 46% of the mass. Microplastics accounted for only 8% of the mass but 94% of the pieces.
The study matters because it showed the patch is accumulating plastic faster than surrounding waters and that lost fishing gear, not consumer litter, dominates its weight.
'Twice the size of Texas' is a fair description of the area. 'An island you can walk on' is false: it is a dilute field of fragments, most too small to see from a boat.