LOS ANGELES, CA (Catholic Online) - In a recently published study, the scientists suggest that the cause was a change in the direction of the Gulf Stream, the current that ferries warm water from the Gulf of Mexico northeast into the Atlantic and along the U.S. East Coast.

Temperatures increased at two deep-water sensors attached to lobster traps off Nantucket by as much as 12 degrees Fahrenheit over the course of several days in October of last year. This pushed water temperatures above 64 Fahrenheit, highly unusual in the waters off southern New England for that time of year. It's also four Fahrenheit higher than temperatures have been at one of these locations in the last decade, said study author and WHOI researcher Glen Gawarkiewicz.

While it only lasted for only a couple weeks, the warm water stuck around for months, into early 2012. These unusual conditions will likely have an effect on marine life near the edge of the continental shelf, the underwater extension of the North American continent that creates relatively shallow waters until it abruptly drops off.

The continental shelf off the Northeast is home to an abundance of fish. Studies in Northeast waters have shown that temperature increases have caused major northward shifts in populations of silver hake, a commercially important fish.

Migratory bluefish and striped bass were also seen off the coast of Cape Cod in spring of this year, which is much earlier than in previous years. More research is required to determine if the Gulf Stream diversion was the cause.

It's still unclear exactly why the Gulf Stream shifted so far to the north, Gawarkiewicz says. One possible explanation is that the heavy rainfall dropped by Hurricane Irene affected its course by altering ocean salinity. Another factor may be that the stream was jolted northward by an eddy of cold water off the southeastern United States that appeared in the fall of 2011, he said.

The Gulf Stream usually only indirectly influences ocean currents and temperatures near the continental shelf south of New England when eddies separate from the Gulf Stream and drift northward, causing limited warming.

© 2012, Distributed by NEWS CONSORTIUM.