An aerial survey of Alaska's shorelines conducted in the summer of 2012 had the goal of examining the impact of debris on the state's coastlines after the March 2011 tsunami that struck Japan and swept an estimated 5 million tons of debris out to sea. The results of that survey indicated that marine debris is crowding Alaska's shores, though just how much of that is directly attributable to the tsunami remains unclear.
During a panel discussion Tuesday at the Alaska Forum on the Environment, taking place in Anchorage this week, experts with the Alaska Department of Environmental Conservation and the National Oceanic and Atmospheric Administration weighed in on the impacts of tsunami debris so far in Alaska, and what might be yet to come.
According to Peter Murphy, Alaska program coordinator with NOAA's Marine Debris program, about 70 percent of that initial 5 million tons of debris sank not long after being washed out to sea. That leaves an estimated 1.5 million tons of debris drifting across the Pacific Ocean, to eventually sink or find its way to shore in places like Oregon, Washington, British Columbia and Alaska -- all places where there have already been confirmed sightings of tsunami debris.
Despite most models of Pacific Ocean currents predicting a later arrival for the tsunami debris, the first of it began showing up in the winter of 2011-2012. To measure its impact, officials turned to Tim Veenstra and his Wasilla-based company Airborne Technologies to evaluate the extent of debris washing onto Alaska's shores.
In a Cessna 185, Veenstra traveled from the tip of the Southeast Panhandle, up the Gulf of Alaska coast, examining Kodiak Island and Cook Inlet in the process, and eventually reaching all the way around to Bristol Bay, on the western side of the Alaska Peninsula. In the process, Airborne Technologies amassed a collection of 8,200 images showing all manner of Alaska shoreline features -- with all manner of marine debris.
"Basically everywhere that we flew, we saw marine debris," Veenstra said during a presentation on the survey results. The company also assembled an interactive map featuring some of the thousands images and their location.
Each of the 8,200 images was evaluated on the density of marine debris visible in the photograph, on a scale of zero -- indicating no visible debris -- to five. Scattered around Alaska's shores are things like freezers, walkers, shipping containers, more mysterious metal cylinders, and boats.
And then there's the foam. Huge amounts of polystyrene foam, which dots Alaska beaches all around the coast, is perhaps the biggest concern. From the air, large chunks are visible, which are revealed to be broken up into smaller pieces on closer inspection, until they get down to small, pebble-sized bits when viewed close up on the ground. And disposing of such foam isn't easy, either.
"This great volume of debris -- it's got to go somewhere," said DEC commissioner Larry Hartig. "And the polystyrene-type material, it's light, but it's bulky. You can't really just take that and put it in landfills ... it's not material that you can burn."
Hartig added that one of the primary concerns over the polystyrene problem is the worry that animals might ingest the material. The aerial survey provides some further evidence of the potential negative effects of marine debris on wildlife.
Slides shown during Veenstra's presentation showed oyster buoys blown inland by strong winds, and photos of bears nearby. One buoy appeared shredded into smaller bits, possibly by a bear.
Another particularly dramatic photograph depicted a humpback whale that apparently became entangled in a net before washing ashore. Veenstra said that this net would be from local waters, and not from the tsunami, but it still strongly demonstrates the impact of marine debris on wildlife.
And the landscape of the debris is rapidly changing. A Maersk shipping container washed ashore near Cape Suckling had been sitting on top of the sand in the earlier part of the year. By the time Veenstra and crew photographed it, it was beginning to sink into the ground.
Also disturbing was the range of the debris, and in particular the fact that some tsunami debris may have even reached the shores of Bristol Bay.
"I was hoping we would not see tsunami debris there," Veenstra said. "When we started this flight, I was looking at it more as a benchmark. Let's get a shot of Alaska before we're impacted with the tsunami debris, and it ended up that we've already been heavily impacted."
It's hard to say for certain, because they lack identifiers like Japanese writing or anything indicating a specific origin. But it's a good bet that many of these items -- particularly oyster floats and clusters of buoys that Veenstra said he doesn't recognize as being used in Alaska -- have Japanese origins.
It's also difficult to tell exactly how much of the debris is new -- previous coastal surveys had significantly lower-resolution video, meaning that the extent of the debris was less clear than it is with the new information.
One thing is clear: Whether from the tsunami or not, the amount of debris on Alaska's shores is reaching epidemic levels, and it's not entirely clear whether there will be funding -- or even the political will -- to clean up some of the state's most isolated beaches.
Contact Ben Anderson at ben(at)alaskadispatch.com