First came the stuff that floats on the surface and is pushed by wind: Buoys, a soccer ball, flotation devices. And, most notably, a rust-stained unmanned fishing trawler in Alaskan waters.
Communities in Alaska, Hawaii, the West Coast and Canada are preparing for the main event from debris pushed offshore by last year's massive Japanese earthquake and tsunami.
About 70% of the debris sank, according to Japanese government estimates.
No one knows how much of the remaining 1.5 million tons of debris is still floating in the Pacific Ocean.
But U.S. and state officials say that some items washing ashore may be from the disaster, which took place 13 months ago and nearly 5,000 miles away. Thousands of people were killed.
"Our models show the outer edge of the debris is at the West Coast and Alaska now," Nancy Wallace, program director and division chief of the National Oceanic and Atmospheric Administration's Marine Debris Program, said Wednesday. The bulk of the debris is north of Hawaii, slowly moving east.
In Washington state, there have been reports of lumber, lightbulbs and fishing items reaching land. Their source has not been confirmed.
Officials can't rule out they came from the tsunami, according to Curt Hart, communications manager at the the state's Department of Ecology.
A volunteer helping in a beach cleanup this weekend along the Washington coast said she found items that appeared to include Japanese writing, according to CNN Seattle affiliate KING. That doesn't prove they were part of the tsunami debris, officials caution.
NOAA said there is no current "debris field." Rather, items, large and small, are scattered over a huge swath of the North Pacific and may make landfall intermittently.
Residents are being told to expect reports of debris to increase and continue over the next couple of years.
What might they see?
For starters, building materials, fishing nets and gear, plastic, barrels and hazardous materials.
Federal, state and local officials held a workshop in Ocean Shores, Washington, on Wednesday, to discuss strategies for handling additional debris. The workshop followed a round of meetings in Washington communities.
"I think my folks have heard a little bit of everything at these meetings," said Tim Church, communications director for the Washington State Department of Health. "The great majority who have come have been low-key about it."
Some people have asked whether any bodies will come ashore. That's not expected.
The top concern is whether radioactive material from the Fukushima nuclear power plant will make landfall.
NOAA has said that scenario is highly unlikely.
"We do not expect to see anything to wash up from Japan with elevated levels of radiation," said Church. "At the same time, we fully appreciate the concern of people. If you spend a lot of time on the coast, if you see the news coverage, you want to see you are safe."
A beach cleanup this past weekend along the Washington shore included checks with radiation-detecting equipment, according to Church. "There just had not been anything so far."