This is an account of HARP #62 and all the people who graciously helped get it home after an unscheduled journey across the Pacific Ocean.
HARPs (High-frequency Acoustic Recording Package) are autonomous battery-powered instruments used around the world to record marine life such as whales, dolphins, seals, and fish. The recorders, designed and developed at the Marine Physical Laboratory (MPL) of Scripps Institution of Oceanography, UC San Diego, are typically deployed to the seafloor and remain there until recovered months later. This was not the case for HARP #62, which prematurely returned to the sea surface near the California coast and was later found on the shores of a Japanese island, more than 10,000 kilometers (6,213 miles) away.
In the spring of 2009, #62 was deployed from the research vessel Robert Gordon Sproul to a depth of about 500 meters near the Channel Islands, offshore of Southern California. The goal of the study was to record the sounds of blue whales and to use these sounds to monitor their migratory return to one of their favorite feeding grounds. A few months after deployment, R/V Sproul returned to the site south of Santa Cruz Island only to find that #62 was no longer responsive to commands sent from the ship. The recorder was either stuck on the seafloor or it had released from its ballast weight early, floated to the sea surface, and was carried away by the ocean currents. Over the next few months, two more attempts to communicate with #62 were made, but to no avail.
Two and a half years later, in the fall of 2011, I received an email message that #62 had been found. The message was from Dr. Toshio Kubo, the physician of Kunigami Village, Okinawa, Japan. He wrote that Tamotsu Ooshiro, a fisherman from the same village, had found #62 on the beach among debris after a typhoon. The instrument had taken a beating after crossing the Pacific and rolling in the typhoon’s surf. No. 62’s frame and flotation were completely gone, but what remained were the four electronics housings and the identification plate with email, phone, and address contact information. What amazingly good luck! And worth trying to get the invaluable data tubes back to California somehow.
We later checked with Scripps physical oceanographer Lynne Talley to understand how the instrument had likely made it so far. Dr. Talley suggested that barring being snagged and dragged by a westbound vessel, “the currents that could connect the Channel Islands to Okinawa would be a southward trip on the California Current, turning westward into the North Equatorial Current, crossing the Pacific and ending up in the Kuroshio, which flows northward and ends up west of Okinawa (between the continental shelf and the Ryukyu Islands where Okinawa is located).”
Dr. Kubo suggested trying to put the tubes on a military transport back to the California, but he also was in the process of transferring to a different town, so he delivered the tubes to Yuu Arakaki at the Kunigami Board of Education. Ms. Arakaki enlisted Steve Martin, an English teacher, to help with email correspondences. After various attempts to contact nearby military facilities, U.S. Navy Capt. William Gaines from MPL established communications with Ronald Gauthier, an oceanographer for the U.S. Navy’s Office of Naval Research (ONR) stationed on Okinawa. Mr. Gauthier drove his truck north to Kunigami Village, picked up the tubes and took them back to his office in Uruma-city. With the help of Garrett Eaton at MPL, the tubes were shipped back to Scripps for evaluation.
In the spring of 2012, the tubes arrived at Scripps, and were then cleaned and opened. The recorder’s sensitive electronic circuit boards were all in disarray and the precious data disk drive connection pins were bent, likely from repeated beating in the surf. This was not the way the internals of these instruments normally looked. The disk drive pins were straightened and carefully connected to a computer to see if any signs of life might exist. All 16 data disks functioned perfectly revealing two months of sounds from whales and dolphins in the Channel Islands! These data now can be integrated into existing and future research projects.
Our research team greatly appreciates the effort of all those involved in the return of HARP #62.
To learn more about whale acoustics at Scripps, please visit us at http://www.cetus.ucsd.edu
Sean Wiggins is a project scientist in the Scripps Whale Acoustic Laboratory