Four of the six baleen whale species found in the western North Atlantic Ocean (humpback, sei, fin and blue) have changed their distribution patterns in the past decade.

Using 281 passive acoustic recorders moored to the sea floor from the Caribbean Sea to Greenland, researchers from the United States and Canada monitored the movements of the whales from 2004 to 2014. The findings of their study was published in the Global Change Biology journal.

“All four whale species were present in waters from the southeast US to Greenland, with humpbacks also present in the Caribbean Sea,” said lead author Genevieve Davis, a senior acoustician at the Northeast Fisheries Science Centre in Woods Hole, Massachusetts. “These four species were detected throughout all the regions in the winter, suggesting that baleen whales are widely distributed during these months.”

The data from the recordings was divided into two time frames—2004 to 2010 and 2011 to 2014—reflecting the timing of climatic shifts in the Gulf of Maine and distribution changes by many species in the western North Atlantic Ocean.

Davis concluded that “a decade of acoustic observations have shown important changes over the range of baleen whales and identified new habitats that will require further protection from human-induced threats like fixed fishing gear, shipping, and noise pollution.”