A team of North American scientists said corrosive, acidified water has been discovered within 20 miles of the shoreline of the U.S. West Coast.

The report, published in Science Express, said the discovery raises concern for marine ecosystems from Canada to Mexico, Oregon State University said Thursday.

Researchers said the acidified water, which is coming up from the deeper ocean, is probably 50 years old.

"When the upwelled water was last at the surface, it was exposed to an atmosphere with much lower CO2 (carbon dioxide) levels than today's," co-author Burke Hales, an associate professor in the College of Oceanic and Atmospheric Sciences at OSU, said in statement. "The water that will upwell off the coast in future years already is making its undersea trek toward us, with ever-increasing levels of carbon dioxide and acidity."

When that CO2 mixes into the ocean water, it forms carbonic acid that has a corrosive effect on aragonite, which is the calcium carbonate mineral that forms the shells of many marine creatures.

The study included researchers from the United States, Canada and Mexico.