抄録
This study was conducted to elucidate a relationship between seagrass distribution and environmental conditions, such as sedimentary materials, sand thickness of its growth bottom and velocity of current, in the lagoon at Bise, Okinawa Island, Japan. Thalassia hemprichii was a dominant species and, though its coverage was high in the calm area near shore, it exhibited the widest distribution in the lagoon than other seagrasses. Other seagrasses, Halodule uninervis and Cymodocea rotundata appeared in a narrower area near the shore compared with T. hemprichii. The coverage of dominant T. hemprichii, was positively correlated with sand thickness, and the sediments as a coral gravel and a living coral, Montipora digitata, which was a dominant coral in the lagoon and grew as a dispersed fragments on the sandy sediments. Many rhizomes of T. hemprichii penetrated into the space among the entangled branches of M. digitata, which could increase physical stability of T. hemprichii. Relationships among growth patterns of seagrasses, kinds of substrates and the stability of the seagrass association against water turbulences were discussed.
