九州西岸牛深周辺のホンダワラ類群落について

抄録

Sargassum vegetation growing in the shallow sea around Ushibuka City, west Kyushu, Japan was surveyed in July, 1959. Eight survey stations were chosen (Fig. 1). At each station, the vertical range and coverage of each species of Sargassum were recorded from direct observations by skin diving. The lower limit of the range of Sargassum vegetation was recognized at about six m below the low water mark. The vertical range of a certain species was not the same among the stations, and the zonal arrangement of the species in relation to the depth was not obvious. The species belonging to the subgenus Eusargassum grow in the rather shallow sea exposed to moderate wave action. Sargassum patens grows predominantly in the shallow sea protected more or less from wave action. S. piluliferum and S. serratifolium were observed growing in deeper places under a wide range of wave action.