A smear of tsunami debris, rather than a massive surge, is likely to wash up on B.C.'s west coast over the next two years, says a Fisheries and Oceans scientist working on an evolving federal and provincial tsunami debris management plan.
However, that smear could amount to about 1.5 million tonnes - more than 10 times the amount of garbage that goes to Hartland landfill in a year - spread along the Canadian and U.S. coast from Alaska to California.
There are few certainties about what will happen with the seaborne debris from the March 2011 Japanese earthquake and subsequent tsunami, said Robin Brown of DFO.
"We are not looking for an intense pulse over a short time period," Brown said.
"We'll probably see a big smear - a long tail of material continuing to arrive."
The tsunami sent about five million tonnes of debris into the ocean, 70 per cent of which is believed to have sunk, Brown said.
"There were a lot of things that weren't floatable items that sank just off shore. So that's the heavy things. The cars. The metals," he said.
While some high-profile items - including a crated Harley Davidson motorcycle pulled from a remote beach in Haida Gwaii, and a 20-metre dock found on a beach near Newport, Oregon - have washed up, only a small percentage of debris coming onto shore has been confirmed as coming from the tsunami.
Much will depend on ocean currents as the highly dispersed debris heads for land. "It's like an inefficient conveyor belt," Brown said. "It does not move smoothly or in an orderly fashion."
The areas least likely to be affected are the mainland, inlets and Strait of Georgia. Communities on the west coast of Vancouver Island and Haida Gwaii are the most likely to see scattered debris.
Victoria is less likely to see debris than the west coast. But experts agree tides and currents could sweep debris into most coastal areas.
Mike Hicks, the Capital Regional District director for the Juan de Fuca electoral area, which includes Port Renfrew, said he is worried that wood is floating unseen just below the ocean surface.
He fears that Island waters could be "overwhelmed by wood material to the point that our fishing industry in Port Renfrew, Ucluelet, Bamfield would be affected, probably all up and down the coast for a few years."
A debris management plan is being developed with First Nations and local governments, but communities will not be left picking up the tab, B.C. Environment Minister Terry Lake said.
"There may be extra costs or extra draws on local government resources for recycling or compacting," Lake said. "We will work with them and try to ensure they are not left holding the bag."
So far, more than $100,000 has been spent on the plan, Lake said.
"If things need to be scaled up, we will look for more resources," he said.
The primary focus will be developing options for collection and disposal of debris ranging from recycling to storage, and integrating volunteer groups.
Lake said the risk of alien species would be assessed, but there are few radiation or health risks. "We think we can manage what comes at us, but we need a plan in place in case it becomes more than we expect," he said.
Jim Standen, who is helping to lead the debris response, said there is a limited ability to track the debris, so the key is watching shorelines.
"We don't want to overreact initially, but we also want make sure we plan so that as it grows or if it grows, we're prepared to grow our response along with that," he said.
