The article mentions the bacteria works at "a steady 86 degrees Fahrenheit." It may work slower or not at all at Pacific Ocean temperatures.
As a result of this article, I'm sure we'll be seeing a lot of groups engineering this bacteria's systems into something that could survive and grow at lower temperatures. Or maybe they'll try to encapsulate the two enzymes in nanoparticles.
may work in a animals stomache?
Exactly. They found it living in plastic eating bugs and it will do good for say - sea turtles, which mistakenly eat plastic and choke. Just force the turtles to ingest a pill with Ideonella Sakaiensis and if they'll be lucky - they'll get new symbiotic pals!
If we're thinking about the same thing - that 'island of plastic' turned out to be incredibly diffuse - something like a few particles of plastic per cubic meter.