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831161 
Journal Article 
Effect of water flow velocity on growth and morphology of cultured Undaria pinnatifida sporophytes (Laminariales, Phaeophyceae) in Okirai Bay on the Sanriku coast, Northeast Japan 
Nanba, N; Fujiwara, T; Kuwano, K; Ishikawa, Y; Ogawa, H; Kado, R 
2010 
Yes 
Journal of Applied Phycology 
23 
6 
1023-1030 
English 
WOS:000296737200010 
Undaria pinnatifida sporophytes, originating from the same
strain, were cultured at the commercial cultivation site exposed to wave action and the
uncultivated site protected from water action of Okirai Bay, Northeast Japan, from January to
April 2007; simultaneously, water flow velocity, water temperature, salinity, NO(3) + NO(2), and
chlorophyll a were monitored to investigate the effect of water environment on their growth and
morphology. Water temperature and salinity fluctuated within the optimal range for their growth
whereas water flow velocity at the cultivation site was greatly fast compared with that at the
uncultivated site. Successive chlorophyll a increases synchronized with NO(3) + NO(2) decreases
were observed only at the uncultivated site for over a month; indicating developments of
phytoplankton blooms and their nutrient consumption under the low-flow condition. Meanwhile,
blade growth rate of cultured sporophytes was higher at the cultivation site than at the
uncultivated site. Their thallus size expressed by six morphological characters (blade length,
stipe length, blade wet weight, stipe wet weight, blade width, and undivided blade width) at the
cultivation site became large in comparison with that at the uncultivated site. Their three
morphological correlations (correlations between blade length and thallus length; blade wet
weight and thallus wet weight; and undivided blade width and blade width) differed between the
sites. They produced a thick and flat blade at the cultivation site but formed a thin and
wrinkled blade at the uncultivated site. These results show the significant impact of water flow
velocity on their growth and morphology. 
Cultivation; Growth; Morphology; Sporophyte; Undaria pinnatifida; Water flow velocity