Tsunami lessons in a bottle: Researchers ask for help finding debris-tracking transponders
10/3/14
Nestled in the sand, hidden amongst debris or floating across the water like a message in a bottle are vessels carrying valuable research information from Japan to North America.
Three years ago, about 30 instruments called transponders were released from various ports in Japan, tasked with recording the patterns of debris from the 2011 Tohoku earthquake and tsunami that was ending up on beaches from California to Alaska.
The remaining transponders’ batteries are now dead, so researchers are asking beachgoers and fishermen to search for the soda bottle-like containers and return them to Oregon State University, which is partnering with Tattori University for Environmental Studies in Japan.
Debris is still arriving on the coast nearly four years after the massive tsunami, bringing with it species that are native to Japan, said Sam Chan, a watershed health specialist with Oregon State University Extension and Oregon Sea Grant.
The paths of marine debris and where it ends up are largely unknown, so charting this would give researchers a better understanding of currents, timing and how species survive the long trip across the ocean through different habitats. It could also assist in being able to locate the estimated 1.5 million tons of debris set adrift by the surging waves.
These transponders have an antenna and record data about their paths and location. While this technology is not new, Chan said, it has never been used for this purpose.
“No one has actually used these to see how marine debris moves,” Chan said. “It can maybe help us learn how to reduce and locate it, and maybe clean it up.”
Originally, three transponders were released and two of the three were found — one in Arch Cape, Oregon, 19 months after it left Japan, and the other near the Haida Heritage Site, formerly the Queen Charlotte Islands in British Columbia, more than three years after it was set adrift, Chan said.
The second group of transponders was sent out about a year after the tsunami, and none from this study group have been found.
“We figure that they would be arriving any time now through next year,” Chan said.
Message in a bottle
Chan said the researchers lost signals on the transponders earlier this summer while they were a few hundred miles off the coast.
The units are small and can only hold a relatively small battery without sinking, so sending out signals 16 hours a day drained the battery before any made it to shore, he said.
“One of the units that we knew about this summer was drifting off the California coast about 200 miles,” Chan said.
With no signal, the researchers need to rely on people returning the instruments.
“We would be happy to pay for the shipping,” Chan said.
However, he wants people to be sure that it is actually a transponder before shipping it.
“We don’t want a whole bunch of people shipping 2-liter soda bottles,” he said.
The transponders are easy to identify. They are orange with an antenna and writing in both English and Japanese that describes what they are and where to return them.
Chan asks that people return the bottles to Oregon State University, rather than the address on the bottle.
Coming ashore
The Northcoast Environmental Center holds regular coastal clean-up days that focus on locations where tsunami debris is expected, said Coastal Programs Director Jennifer Savage.
“We encourage people to keep an eye out for anything that could potentially be tsunami debris, but we haven’t had any reports,” she said.
A 21-foot panga boat from Rikuzentakata, Japan, found on a beach south of Crescent City in April 2013 was the first documented piece of tsunami debris to reach California’s shores.
Savage said the Samoa Dunes Recreation Area and Del Norte County’s Point St. George are locations where debris often ends up.
“For whatever reason, the currents send things in the water to those beaches,” she said. “It is quite likely that if something were sent, like a transponder, it could end up there.”
The transponders are just one of many ways to study the debris that was swept into the ocean in the 2011 tsunami, said Nir Barnea, West Coast regional coordinator for the NOAA Marine Debris Program. He has worked with Oregon State University to get out information about the transponders.
“It is one piece of the puzzle,” Barnea said. “There are a lot of information sources, because this was really an unfortunate event, and we are still learning from it.”
While aerial observation, satellites and shoreline surveys are other ways that marine debris is tracked, Barnea said this is one more avenue to learn and to get information Barnea said severe marine debris events like the tsunami in Japan are rare and create public interest in where the debris goes.
Learning about the debris paths are important to the public, fishermen, the Coast Guard and other agencies who are affected, he added.
“There was a lot of need to have more information,” Barnea said. “It is very important to know how to respond to this and to learn from this.”