Distribution and phenology of brown algae Undaria undarioides on the southern coast of Uchiura Bay, Shizuoka, Japan

This study was conducted in order to clarify the distribution and phenology of Undaria undarioides (Laminariales, Phaeophyceae) on the southern coast of Uchiura Bay, Shizuoka, Japan. A distribution survey carried out in late April 2008, by a scuba diving team in this area, confirmed the growth of U. undarioides in most parts of the area. The phenology survey was conducted from November 2008 to July 2009, at the depth of 5 m in the same area. U. undarioides appeared in December, grew to their maximum length in late March, and then matured in April. Afterwards, the thallus of U. undarioides started to decrease in size in May and disappeared entirely by July. The shape and size of U. undarioides were compared at their growing depths of 2, 6, 10, 14 and 18 m on March 28, 2010, revealing that thalli grown at the depth of 6 m were significantly the largest and that the size decreased as the depth increased.