研究報告37号

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1 Bathymetric distribution and phenology of Ecklonia kurome in the western Wakasa Bay, the Sea of Japan. Tomokazu Nishigaki and Akio Douke Bathymetric distribution of large brown algae, and temporal variation in growth and maturation of Ecklonia kurome is reported from July 2012 to July 2013 off the southeast coast of Isokatsura-jima, western Wakasa Bay, in the Sea of Japan. In waters shallower than 4.5 meters, Sargassacean species were dominant, whereas E. kurome, Sargassum ringgoldianum ssp. coreanum and S. macrocarpum characterized deeper waters. Lengths of central lamina and longest lateral pinna and wet weight of E. kurome were greatest in early summer (May-June), and least in winter (December-February). Sorus formation was observed between October and December. Ecklonia kurome 2004 Turbo cornutus km Fig.1 Fig. 1 Study sites ( ) for bathymetric distribution of Sargassacea species and E. kurome, and phenology of E. kurome off the southeast coast of Isokatsura-jima, Wakasa Bay, Sea of Japan

2 m 10 m 5 m 2003 Sand Pebble Cobble Boulder Rock m 1 m 1 m 2 m 0.5 m 0.5 m 2 10 cm m Sargassum ringgoldianum ssp. coreanum 2 1 cm ACL-208DK ACL-215DK 5 m Fig m 13.2 m 60 m m m 5 m Table m 8 40 m 100 m m Sargassum macrocarpum 5 Fig. 2 Depth and percentage cover of bottom on a line transect (200 m) off Isokatsura-jima. 2

3 Fig. 3 Productive structure of Sargassacea species and E. kurome at depths of 2, 5 and 8 m off the southeast coast of Isokatsurajima

4 Table m 0 10 m Sargassum micracanthum Sargassum horneri m m Sargassum confusum Sargassum hemiphyllum Myagropsis myagroides Sargassum patens m m Sargassum siliquastrum m m m m m Fig.3 2 m cm 1,700 g m -2 5 m cm cm cm cm 8 m 5 m 390 g m m m -2 g m , Fig Fig.5 1,670 5,320 g m -2 Sargassum fulvellum ,260 g m ,200 g m g m g m g m -2 1, , g m Fig m m m m -2 Fig.7 Fig mm mm mm g 8 Fig. 4 Changes in water temperature and salinity at 5 m depth between July 2012 and July 2013, at E. kurome phenology study site, Isokatsura-jima. Fig. 5 Monthly changes in standing crop of Sargassacea species and E. kurome, July 2012 to July

5 Fig. 6 Temporal variation in age-class density of E. kurome, July 2012 to July Fig. 8 Temporal variation in percentage of adult E. kurome plants with sorus, July 2012 to July mm mm mm mm g Fig. 7 Temporal variation in plant length ( ),central lamina length ( ),longest primary pinna length ( ) and wet weight ( ) of adult E. kurome plants, July 2012 to July Mean S.D. for 6 samples mm mm mm 42 9 g mm Fig m 4.5 m Table2 Fig.3 2 m 5 m Phyllospadix japonicus 5 6 m

6 m Fig.3 Fig.5 5 m Fig Fig Fig Fig.6 Fig.5, : : : : : : : : : U90044: : : b. 30: : :

北海道水産試験場研究報告

北海道水産試験場研究報告 Sci.Rep.Hokkaido Fish.Res.Inst. Age determination of Japanese flounder Paralichthys olivaceus, caught from Ishikari Bay, using cross sections of otoliths NOBORU HOSHINO Central Fisheries Research Institute,