One of the major goals of this expedition is to research a specific type of beach trash…Oyster Farm Tubes. These tubes, which are 6″ plastic tubes, are used during the large-scale farming of oysters in Japan, most notably Hiroshima and Okayama. These pipes provide a base for the oyster to attach and grow. The benefit of these tubes is that they provide a very easy retrieval system for the farmers because they simply cut the line that holds the tube and all the tubes slide off. In the picture below, you can see the tubes scattered throughout the beach, especially starting from the lower right side.
The problem arises when these tubes are founds numbering in the hundreds on various beaches in Japan (Seto Uchi Sea). These tubes have been found in the stomachs of the Albatross of Midway island and as well as Tuna caught in the Pacific ocean.
Whats unique about this problem, as compared to beach trash in general which can be attributed to many countries, is that this impending ecological disaster is concentrated in one country (Japan) and can be addressed by modifying the current farming practices of a relatively small group of people.
To set the context, this problem has also been investigated by a researcher at Kagoshima University named Shigeru Fujieda, who has published papers on the topic. His research shows the density of pipes found on beaches within the Seto Uchi Inland sea. In these pictures below (Short and Long pipes), you can see the concentration of pipes on the beaches of the Seto Uchi Sea. The picture labeled “short pipes” is especially telling of the problem because the highest concentration is located within the confines of Hiroshima bay. Also, one point of note is the drift of the pipes, the tidal current in the Seto Inland Sea brings the pipes in a west moving direction to the pacific ocean via the Bungo Strait.