| Budget Amount *help |
¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 2003: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 2002: ¥900,000 (Direct Cost: ¥900,000)
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| Research Abstract |
To determine fish assemblage structure in tropical seagrass beds and how its structure differs from those in adjacent coral and sand areas, visual censuses were conducted at Amitori Bay, Iriomote Island, Japan, in August and November 2002. five 1m×20m transects were established at each habitat (seagrass bed, coral area, and sand area), and all fishes within the transect area were counted.the numbers of species and individuals of fishes were higher in the coral area than in the seagrass bed and sand area.
To clarify the effects of changes in seagrass leaf density and height on recruitment of the cardinalfish Cheilodipterus quinquelineatus, which is a common species in troical seagrass beds, a field experiment using artificial seagrass units (ASUs, including (1)long dense leaves (LD-units), (2)long leaves thinned to about 40% of LD-unit density, (3)dense leaves shortened to 40% of LD-unit height, and (4)no leaves (control), were used, recruits on each ASU being counted daily over 14 consecutive days. The mean number of C. Quinquelineatus recruits per replicate on LD-units was significantly greater than on the other unit types, indicating that longer denser seagrass leaves had a significant impact on recruitment of the species.
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