Strong winter tradewinds are contributing to an increase in debris from the March 2011 Japanese tsunami reaching coastal areas off Kauai and other Hawaii islands, sometimes smashing against reefs and carrying suspected alien species.
Scientists say in the last few weeks, semisubmerged bulky items have washed up, including pieces of refrigerators — some with seaweed attached — a boat, a concrete-encased foam dock and bundles of buoys, many with mussels and barnacles.
Officials have confirmed that 21 tsunami debris items have reached Hawaii, Alaska, Canada and the West Coast.
University of Hawaii researchers at the International Pacific Research Center said the debris tends to drift based on its weight and the winds and currents.
Center senior researcher Nikolai Maximenko said tradewinds are helping to move more debris south to Hawaii.
"I think we are receiving more generally because of our strong winds," he said.
According to the center’s computer model, a small number of light objects influenced by high winds might have skirted Alaska, floated along the West Coast and are close to the equator south of Hawaii, possibly returning to Asia.
"We’re suddenly seeing bunches of these things coming in more than ever," said Carl Berg, chairman of the Kauai chapter of the Surfrider Foundation. "The kind of stuff coming in and the amount of stuff coming in indicates there’s a change, and this is worrisome. … We have to be ready to very quickly take it off the beach and discard of it in a proper manner."
Berg, a zoologist, said Surfrider has been working with state marine conservation officials to properly collect the debris, including a kind of mussel apparently not found on Kauai shorelines.
State ocean experts are determining the species of mussels and seaweed to see whether they are native to Hawaii and whether they might be a threat to Hawaii’s ecosystem.
Berg said volunteers who normally find a marine buoy once a month have found bundles of buoys in a single day, as well as several pieces of refrigerators.
Berg said a rope with a lot of white buoys was found about a week ago on the eastern shore of Kauai.
He said mussels were found growing on multicolored buoys off Lepeuli Beach two weeks ago in northern Kauai, and dark green algae was found growing on a refrigerator off Waipake.
On Oahu within the last week and a half, a boat was discovered off Kahuku, and a concrete-encased foam dock about 6 to 7 feet long by 3 to 4 feet wide was found off Makapuu Point, scientists said.
Of the suspected items, federal officials working with the Consulate General of Japan in Hawaii have confirmed a yellow buoy found in the ocean near the Pacific Missile Range on Kauai on Jan. 18 was tsunami debris — the sixth item to be confirmed in Hawaii.
Maximenko said much of the debris looks like tools and equipment built for maritime boating activity, things designed to survive in the ocean.
Based on computer models developed with his associate, Jan Hafner, half-submerged objects influenced little by the wind will drift into garbage patches floating between Hawaii and California, he said.
Maximenko said the heavy debris objects may include some of the 100,000 pine trees broken and set adrift by the tsunami.
"We don’t know if they’re still floating or not," he said.
Maximenko said scientists are still gathering information to determine the accuracy of their models and probably won’t know about the kinds of objects drifting in the ocean between Hawaii and the West Coast until the summer, when sailboats typically make crossings and are able to report their observations.
