Humboldt squid have been moving northward into California's Monterey Bay for the last five years, gobbling up Pacific hake, an important catch for commercial fisherman, according to a report published this week by Proceedings of the National Academy of Sciences USA. Spying via remote video, scientists found that the normally tropical squid have been reproducing in the bay's cooler waters since 2002. They suggest that the predators, which can grow up to six feet long, were ferried into the area by warmed ocean currents during the El Niño years 1997 and 2002.