For some Alaska islands there’s a ship-borne risk even scarier than an oil spill

As Arctic shipping increases, so does the threat of a so-called "rat spill" — an invasion of rats from a sinking ship — that can have far longer lasting ecological effects than an oil spill.

The most dangerous ecological disaster for the islands of the Aleutian chain and the Bering Sea, biologicals have long warned, wouldn’t be an oil spill, but a “rat spill” — an invasion, from wrecked ships, of the voracious rodents against which native species have no natural defenses.