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To examine the effects of substratum types on the growth of Caulerpa okamurae, sand surface and sand burial experiments were conducted. Five assimilators (erect fronds) per replicate were cultured for 15 d on the surface of three different treatments: fine sand (200 μm), coarse sand (600 μm), and no sand (control). Also, three stolons and three assimilators were buried by fine grain or coarse grain sands and incubated for 15 d. In both experiments, other culture conditions included 25°C, 30 μmol photons m-2 s-1, and 16 : 8 h L : D (light : dark). In both experiments, stolon + assimilator-, assimilator-, and stolon-weights were measured. Relative growth rates (RGRs) of stolon + assimilator weights ranged from 0.43 to 1.95% d-1 at no sand and fine sand treatment, respectively. RGRs for the weight of stolon + assimilator and new assimilators were significantly greater on the fine- and coarse sand surface than the control. In the burial experiments, RGRs of stolons (4.28% d-1 at coarse sand and 5.57% d-1 at fine sand, respectively) were significantly greater than those of assimilators (1.38% d-1 at fine sand and 1.82% d-1 at coarse sand, respectively). When stolons were buried, RGRs for assimilators were greater at the fine sand than at the coarse sand treatment. On the other hand, RGRs of buried assimilators for total frond weights and for newly produced stolons were significantly greater at the coarse sands than at the fine sands. In conclusion, C. okamurae grew well with all substrates of sands and showed better growth on fine sands than coarse ones. This result suggests that the growth of stolons and assimilators of C. okamurae is stimulated after stable attachment to the sand substrates by rhizophores. In addition, stolons showed higher growth rates than the assimilators in the sand burial states, indicating that stolons are more tolerant to low light than assimilators of C. okamurae.

Silvetia siliquosa is an ecologically and commercially important brown alga that is harvested from its natural habitats, but its population has recently been diminishing along the Korean coast. To develop new techniques for algal population restoration, we tested two newly developed transplantation methods (using polyethylene ropes and natural rock pieces) at two study sites, Gwanmaedo and Yeongsando, on the southwest coast of Korea, from May to November 2014. The transplants on polyethylene ropes showed significantly greater survival, maturity, and growth than those on natural rocks at both study sites. Newly recruited juveniles (

2 of Ulva frond, hole areas ranged from 0.37 to 5.94 cm 2 , and between 4.9 and 36.2 holes were observed. Fourteen residential animal species were observed at the three evaluated sites, 75.0 (Haseom) to 408.7 individuals 100 g -1 Ulva (Pohang) per site. The dominant residential species at each site differed with Amphithoe sp. at Haseom, Monodonta spp. at Pohang, and Pagurus sp. at Woedo. The growth (frond area, wet weight) and hole number of Ulva fronds, and the number of residential animals were significantly greater in samples collected from the sheltered shore than the wave-exposed shore of Seongsan. The present results showed U. australis grew well at sheltered shores and had more holes on the fronds due to abundance of residen- tial animals. The dominant residential animals (crabs, gammaridea, and snails) were similar in the Ulva populations of sheltered and wave-exposed shores, but greater species diversity was observed at the exposed shore (18 species ver. 11 species). In conclusion, U. australis is a keystone species providing habitat to various invertebrates and frond holes are positively correlated to the number of residential animals.

Twelve morphological characters and the biochemical composition of Undaria pinnatifida f. distans sporophytes growing on the rocky shores of Jindo and Wando and on cultivation ropes in Kijang were measured to determine whether each population could be characterized by morphological features and biochemical composition. The goal of this study was to compare phenotypic variations between populations as they relate to environmental conditions. The sporophytes of the Kijang population were two times longer and 19 times heavier than those at Jindo. Sporophylls of the Jindo U. pinnatifida population were significantly smaller in length, width, frill number, and weight than those at Wando and Kijang. Kijang Undaria plants showed the highest contents of total protein, crude fiber, total amino acids, the amount of essential amino acids, the proportion of total unsaturated fatty acids, and eicosapentaenoic acid. However, the Jindo population showed the greatest content of carbohydrates, lipids, and minerals (Zn and Ca) of the three U. pinnatifida populations. In particular, Zn content of Jindo plants was 30 times greater than that of Kijang plants. Thus, the proximate composition, mineral composition, amino acids, and fatty acids of Undaria pinnatifida plants were distinguishable among the three representative Undaria populations evaluated. These results suggest that morphological and biochemical differences of the three U. pinnatifida populations can be attributed to differences in environmental conditions of their habitats.

The stress tolerance ability of Pelvetia canaliculata (L.) Dcne. Et Thur. and Fucus spiralis L. to temporary and periodic emersion stress was examined in order to test the following hypotheses: The upper shore alga, P. canaliculata is more tolerant to desiccation than F. spiralis in the germling stage and the former outgrows the latter under desiccation stress; Germling stress tolerance of the two species is age-specific; Crowding of germlings protects them from desiccation, ir respective of the species involved. Germling growth of the two species was retarded with increasing exposure period and was age-specific, as they were air-exposed at an earlier stage. After 16 days, the length of Pelvetia germlings was similar between 2-day-old germlings (125-140 µm) and 7-day-old germlings (134-140 µm), which were air-exposed during the same period (0, 6, 12, 24, 48, and 72 h) at the two different ages. However, Fucus germlings were significantly larger at 7-day-old germlings (211-277 µm) than at 2-day-old germlings (184-278 µm), especially in the treatments of 48 and 72 h. These results indicate that Fuscus grow faster than Pelvetia and that the growth response of germlings to temporary emersion stress is more sensitive in Fucus than that in Pelvetia. Growth of germlings of both species was reduced with increasing density under favorable growth conditions (submerged control and 6 h / 12 h exposure treatments) in the periodic air-exposed experiments using tidal tanks, but was enhanced under severe emersion stress conditions. P. canaliculata showed better growth at 6 h exposure treatment than that of the control, under continuous submergence, indicating that Pelvetia germlings require a periodic exposure period. Fucus germlings always grew faster than those of Pelvetia and did best in mixed cultures, whereas Pelvetia did least well when mixed with Fucus germlings. The adverse effects of F. spiralis on P. canaliculata were greater than those of Pelvetia cohorts. The outcome of interspecific competi tion between F. spiralis and P. canaliculata gemlings was slightly altered by exposure period but not to such an extent as to change the outcome.