Even hardy marine creatures are showing signs of stress from the disastrous effects of the March 11 Great East Japan Earthquake.
Even hardy marine creatures are showing signs of stress from the disastrous effects of the March 11 Great East Japan Earthquake.
Abnormal shell patterns have been found on clams off the coast of Fukushima Prefecture since the tsunami radically changed their habitat, according to research team led by Kenji Okoshi, a professor of environmental dynamic analysis at Toho University.
Okoshi's team studied the density of clams in their habitats and other changes in May at Matsukawaura bay and inlets in Soma, Fukushima Prefecture. These areas are noted for their clam cultivation.
Of the 216 clams studied, 192, or about 90 percent, had ruts in the middle of their shells. The ruts marked the start of different colors and patterns leading toward the edges, the team said.
In contrast, a survey conducted in June 2009 in Matsukawaura bay found only 10 percent of the clams showed changes in their shells, such as parallel striations.
Okoshi said the latest clams likely came under great stress due to the long distances carried by the tsunami, the sudden change in salt concentration, and the unnatural mix of sand and mud in the seabed.
Okoshi added, "This phenomenon itself won't necessarily affect the taste and quality of the clams."