Experts say they've detected radiation on Vancouver Island that's definitely from the leaking Fukushima Daiichi nuclear reactor that polluted the water during an earthquake and tsunami that killed 16,000 people in 2011.

It's the first time radiation has been found on the shores from the disaster, according to University of Victoria chemical oceanographer Jay Cullen. He said low levels of the isotope Cesium-134, which could've only come from Fukushima, were found in the water on Feb. 19 off a dock at Ucluelet, British Columbia.

Last November, the first sample containing detectable radioactivity from Fukushima was discovered about 90 miles off the coast of northern California.

(MORE:)

Over the past 15 months, scientists and citizen volunteers have been collecting water samples at more than 60 sites along the Canadian and U.S. west coasts and in Hawaii as they've looked for traces of radioactive isotopes from Japan.

"This is the first sample that's been collected in North America with this contaminated plume of sea water, which we've seen offshore, but it's the first time we've actually seen it at the shoreline," Cullen said.

He said the arrival of radioactive water on North American shores from Japan was expected this year. The distance from Japan to Ucluelet is more than 4,700 miles.

"The levels we are seeing are so low that we don't expect there to be impacts on the health of either the marine environment or people living along the coast," Cullen said.

"We're more than a thousand-fold below even the drinking water standard in the coastal waters being sampled at this point. Those levels are much, much, much lower than what's allowable in our drinking water."

(WATCH: )

Cullen said in a statement that if a person swam for six hours each day in water with Cesium levels twice as high as those found in Ucluelet, they'd receive a radiation dose that is more than 1,000 times less than that of a single dental X-ray.

Since the March 2011 earthquake and tsunami triggered the nuclear disaster, there has been widespread concern about the potential danger posed by radioactivity from Japan crossing the Pacific Ocean.

Cullen leads a marine radioactivity monitoring network formed last August that includes scientists in Canada and the U.S., health experts, non-governmental organizations and citizens who help collect samples along the Pacific coast.

The InFORM Network, or Integrated Fukushima Ocean Radionuclide Monitoring, received $630,000 in federal funds for three years through the Marine Environmental Observation Prediction and Response Network.

Research partners in the network include Woods Hole Oceanographic Institution in Massachusetts, Health Canada, the University of Ottawa, the University of British Columbia and Fisheries and Oceans Canada.

MORE ON WEATHER.COM: Japan's 2011 Tsunami

In this image a man climbs onto a boat wedged on a bridge on March 18, 2011 in Ishinomaki, Japan. (Chris McGrath/Getty Images)