The researchers at the University of Maryland Center for Environmental Science and the Chesapeake Biological Laboratory question the long-held belief that a lack of predators and competitors was the primary cause for the population explosion observed following overfishing of commercially important species during the 1980s.

Researchers Michael Frisk, Thomas Miller, Steve Martell and Katherine Sosebee argue the increase of winter skate was the result of a migration to the area from adjacent or connected waters. If true, the scientists said their hypothesis could have significant implications for management of the fishery.

"If the regime shift observed on Georges Bank was driven purely by population dynamics internal to the system, then local management action has the potential to drive the system back to its former state," said Frisk. "If, on the other hand, skate populations in the northwest Atlantic exhibit connectivity, as suggested in our alternative hypothesis, then management of skates must be integrated across the whole northwest Atlantic."

The research appeared in the January issue of the journal Ecological Applications.