http://marinedebrisblog.wordpress.com/2014/01/03/transponder/

Help Needed: Have You Seen This Transponder?
January 3, 2014 by NOAA Marine Debris Program

By: Nir Barnea and Asma Mahdi

Attention marine debris cleanup crews, beachcombers, beach visitors, and 
park recreation staff! Your help is needed to find transponders, 
released by the Tattori University of Environmental Studies (TUES) in 
Japan, and report such finding with a picture and its location.

As part of an on-going study* to research the movement of marine debris 
in the North Pacific, researchers at TUES released transponders, shaped 
like 2-liter orange soda bottles with an antenna, from northern Japan 
during four phases in June and October 2011, January 2012 and January 
2013. This study is particularly relevant to the movement of the debris 
washed out to sea by the powerful tsunami that struck Japan on, March 
11, 2011.