The Gigartinaceae (Rhodophyta) is represented in New Zealand by at least 23 species, the systematic relationships and taxonomy of which are still incompletely understood. There is very high endemism in this group, with only two species reported from areas outside the New Zealand region, and the majority restricted to portions of the New Zealand archipelago. There have been detailed studies of the polysaccharides of New Zealand members of this family, with a view to identifying possible commercial applications and novel taxonomic markers. In this review the systematics, distribution, cell wall chemistry and potential commercial use of members of this family from New Zealand are discussed.

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Two genera of marine red algae, Rhodogorgon and Renouxia, are reported from Thai waters. Rhodogorgon ramosissima was collected from the east coast of the Gulf of Thailand (the Pacific Ocean) and Renouxia antillana from the Andaman Sea (the Indian Ocean). The two genera differ from other calcified red algae as they possess calciferous cells surrounded by calcite husks. The present study indicates that Rhodogogon ramosissima and Renouxia antillana occur in Thailand and provide additional records of the distribution of the gorgonian-like marine red algae in the southeast Asian countries and the Pacific Ocean.

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Ecological impacts of Diadema species on benthic communities in the warm temperate waters of Northern Hemisphere, Japan in the Northwest Pacific and Macaronesian in the Northeast Atlantic, were reviewed in a concerted way as a result of two independent research groups. In Japan, two species D. setosum (known since early 1800's) and D. savignyi are distributed from southern to central Japan (up to 38°N in the Sea of Japan and 36°N on the Pacific coast) and causing locally patchy or zoned urchin barrens. In D. setosum, sexual maturity occurs only in summer; its grazing on macroalgae is highly dependent on water temperature and the algal size; mass mortality was recorded during cold temperatures in winter of 2002 (<12°C). In Macaronesian Archipelagos, Diadema antillarum-b, which is genetically separated from the western Atlantic population (D. antillarum-a), is widespread on rocky bottoms. D. antillarum-b matures throughout the year and seems to be much more voracious than D. setosum by means of feeding larger species of macroalgae and causing patchy or extensive urchin barrens. Besides elevation of water temperature, a variety of anthropogenic factors (e.g., increase of artificial structures in Japan, overfishing in Canary Islands) should be considered for the cause of the recent increase of Diadema barrens. In both areas, removal of Diadema has resulted in the establishment of macroalgal beds, but the implementation of long-term sustainable fisheries management, including the declaration of effective MPAs as well as the enactment of mitigation programs such as sea urchin control campaigns and/or predators restocking, should be considered as appropriate measures to control the population demography of Diadema and, consequently, to recover sound and balanced trophic structures on rocky bottoms. The combined effects of these actions may enhance the return of healthy marine vegetation in shallow coastal areas, which are considered at the base of the trophic chain in coastal ecosystems.

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Fucoidan and laminaran in brown algae are important polysaccharides for industrial use because of their functional activities. We applied batch-adsorption chromatography using a diethylaminoethyl (DEAE) Sephadex A-25 resin to estimate fucoidan and laminaran contents with the goal of establishing a routine technique for use in ecological and physiological investigations. The mean recoveries of commercial fucoidan and laminaran by batch-adsorption chromatography were 99.1% and 97.6%, respectively, suggesting that this separation method is beneficial for quantitative analysis. In eight brown algae containing 3 species of Laminariales and 5 species of Fucales, fucoidan and laminaran contents were 1.75-12.2% dw and 0.44-6.99% dw, respectively. In this study, the most fucoidan-rich alga was Kjellmaniella crassifolia (12.2% dw), followed by Cystoseira hakodatensis (8.1% dw). In contrast, laminaran content was the highest in Sargassum patens (7.0% dw), followed by S. horneri (5.9% dw). The method using batch-adsorption chromatography is quick and can be used to measure many samples simultaneously. Therefore, this simple method is very useful for estimating fucoidan and laminaran contents as a routine technique for searching for useful species and for eco-physiological research.

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The potential of the red alga Gracilaria bursa-pastoris as a potential biofilter component was tested in an integrated multi-trophic aquaculture systems (IMTA). Nutrient uptake characteristics of the species in media with inorganic nitrogen showed inhibition of uptake of nitrate by ammonium based on significant differences between their mean uptake rates (19.26 μmol g dry wt^-1 h^-1 for nitrate and 66.11 μmol g dry wt^-1 h^-1 for ammonium) and oscillations in their substrate concentrations within the 48-h incubation period. With the red sea bream (Pagrus major) effluent water, G. bursa-pastoris reduced 35.63 ± 11.10 %, 29.14 ± 19.65 % and 55.67 ± 13.80 % for nitrate, phosphate and ammonium, respectively. Mean uptake rate for ammonium (758.35 ± 378.65 μmol kg wet wt^-1 h^-1) in the effluent water was higher compared to nitrate and phosphate and supported high growth rates (11.70 % d^-1) and N:P ratio (19.64). Dark uptake of nutrients and suppression of ammonium over nitrate was observed in both inorganic N media and fish effluents.
This study shows that G. bursa-pastoris is an efficient biofilter based on its affinity for ammonium, capacity for dark uptake and high growth rate in fish effluents. The biomass obtained can provide additional revenue through its use as human food, source of agar and as feed for abalone.

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Seasonal changes in the biomass and occurrence of wild Saccharina japonica (J.E. Areschoug) C.E. Lane, C. Mayes, Druehl & G.W. Saunders sporophytes were investigated at the coast of Cape Ohma, northernmost point of Honshu island, Japan. The blade sizes of marked 25 - 30 sporophytes were monitored at a depth of 14 m each month from November 1991 to December 1994. Their blade elongation was monitored by recording the position of punched holes on the blades to calculate growth rates. The data of algal standing crop, water temperature and NO₃-N concentration were also obtained at each time of sampling. The sporophytes of S. japonica occurred every year except 1992. First- and second-year-old sporophytes grew to the maximum length of ca. 0.8 m and 2 m in spring, respectively. Both of them formed zoosporangial sori from October to February. Regeneration of the blade was observed from October to March for the first-year-old sporophytes. Deterioration of the second-year-old sporophytes occurred from November to December. Annual elongation of the blades of first- and second-year-old sporophytes at the meristematic part was calculated as 1.6 m and 1.8 m, respectively. The blade growth had a significant negative correlation with water temperature, but positive correlation with NO₃-N concentration. First- and second-year- old sporophytes grew at the water temperature lower than 20 °C and 14 °C, respectively. The growth rates decreased at rates of 1.7 mm day^-1 for former and 2.8 mm day^-1 for latter per 1 °C increase.

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Surveys and study of green algal bloom occurred in the Yellow Sea during 2008-2009 were conducted; the algal samples were collected on the sea during the surveys. Green algal bloom distribution and species composition were studied, satellites remote detection data were either be intergraded with the field surveys, and illustrated the correlation between the green algal distribution, drift tendency and ocean current. The dominant species of the drifted blooming green alga was Ulva prolifera (Müller) J. Agardh (Chlorophyta, Ulvales), which mainly distributed within 34°N-37°N in latitude in the Yellow Sea during the middle of July. In addition to the vegetative propagation, the spores were released intensively from the mature algal branches, and formed new branches within the short time. Satellites remote detection indicated that the floated green alga could be drifted with the sea current towards the north direc- tion and formed green algal bloom propagules intensively. Causes of the green algal bloom occurrence in the Yellow Sea were discussed.

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In order to increase the algal fresh weight of a red alga, Gracilariopsis chorda (Holmes) Ohmi, with indoor culture, four kinds of the algal fragments (5A: 5 mm long apical, 5I: 5 mm long intercalary, 3I: 3 mm long intercalary, 2I: 2 mm long intercalary fragments) were evaluated to determine a suitable starting material for unialgal culture. During the unialgal culture, new multiple branches grew from a regeneration surface of intercalary fragments. Although the algal fresh weight after eight weeks of cultivation were significantly larger in 5A and 5I than in 3I and 2I, the rate of increase (i.e., the ratio of the fresh weight to initial fresh weight after eight weeks of cultivation) were in the order of 5I (53.0-fold), 3I (80.4-fold), 5A (93.7-fold), and 2I (114-fold). The relative growth rate (RGR) of 5A was higher than that of 2I before three weeks of cultivation, but after four weeks of cultivation RGR of 2I was higher than that of 5A. From these results, among the algal fragments tested, 2I seems to be the best initial fragment for G. chorda unialgal culture. On 20 l scale culture, the average fresh weight of 2I was 7.28 g/tank after eighth week culture.

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The experiment was carried out with subcutaneous injections of Methotrexate (MTX), a commonly used antimetabolite drug, is known to induce intestinal inflam- mation. We investigated whether a hot-water extract of Prasiola japonica Yatabe (PJ) can be used as an effective remedy against MTX induced intestinal injury. A hot-water extract of PJ was administered orally to mice with MTX-induced intestinal inflammation. Experiments were carried out in which the mice were given PJ by gavage at an initial dose of 5 or 10 mg/kg body weight for 6 days. The mice were also given a subcutaneous injection of MTX (7.0 mg/kg body wt/day) daily throughout the 6-day experimental period. The shortening of the small intestine and gastrointestinal mucosal ulceration induced by MTX were attenuated following oral administration of the PJ extract. The numbers of apoptotic cells and Proliferating Cell Nuclear Antigen-positive cells in the intestinal mucosa of the PJ-treated mice were lower than those in the MTX- treated mice. These results indicate that the extract of PJ could protect against MTX- induced damage of the small intestine. Folic acid was found to be present in the PJ extract at the concentration of about 2.5μg/mg, and may be considered as having been responsible for the decrease in the severity of the MTX-induced damage of the small intestine.

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Since the seminal work of K. M. Drew in 1949 linking the genera Porphyra and Conchocelis as phases of the same life history, it was possible to achieve significant advances in the mariculture of the most economically important red algal genus. Due to the conspicuity of the leafy phase, which forms dense belts on rocky coasts, and the cryptic habit of the filamentous phase, it is just natural that the ecology of the leafy phase has received much more attention from biologists. In fact, very little is known world wide about the natural populations of the filamentous phase. Here we describe a simple method to look for conchocelis on calcareous shells and document, for the first time, the distribution of the conchocelis phase of two Brazilian species of Porphyra in the field. Our data show that the conchocelis phase is perennial, and colonizes abundantly shells of live mollusks and barnacles on the intertidal zone.

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Seaweeds are macroscopic, multicellular marine algae. Their commercial extracts have recently become popular as plant biostimulants, which may also impart tolerance to treated plants against abiotic stresses. Seaweed extracts have been reported to enhance root growth, plant health and biomass under various stress conditions, such as salinity, temperature stress and hypoxia. However, the mechanism(s) responsible for these varied responses remain unclear. Here we briefly review the plant abiotic stress alleviating effects of seaweed extracts and the potential role of chemical constituents of seaweeds in those extracts in such effects.

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Carrageenan is used in a wide range of industries, especially in the food industry, where their gelling qualities and viscointensifying properties are greatly valued. Molecular characteristics and structural properties of carrageenans extracted from the two seaweeds (Rhodophyta), Kappaphycus alvarezii collected in Indonesia and Solieria pacifica collected in Japan were investigated. Carrageenans were isolated and the resulting extracts were recovered by precipitation with isopropyl alcohol. Carrageenans from K. alvarezii and S. pacifica were identified as kappa- and iota-carrageenan, respectively, by use of Fourier transform infrared spectroscopy (FT-IR). Carrageenan from S. pacifica provided no gel by cooling, while that from K. alvarezii made gel upon cooling. The weight average molecular weights determined by gel permeation chromatography (GPC) of carrageenans from K. alvarezii and S. pacifica were 6.6×10⁵ and 1.9×10⁵, respectively. Intrinsic viscosity, [η], of carrageenan from K. alvarezii was 5.1 dl/g, while that from S. pacifica was 5.5 dl/g. From these parameters, the carrageenan extracted from K. alvarezii collected in Indonesia has high potentiality for a commercial product because of high gelation ability and molecular weight. While, carrageenan from S. pacifica collected in Japan needs improvement of the extraction procedure to obtain a gel-formable one.

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Morphology and sulfate polysaccharide relationship were compared among the three species in the Caulerpa collected from different habitats in Thailand. Plants of Caulerpa sp. (CR), and C. racemosa var. macrophysa (CMR) were collected from Rayong province, the C. racemosa var. corynephora (CCT) from Trang and C. lentillifera (CLC and CLP) from Chachoengsao, and Phetchaburi provinces, respectively. Based on six morphological characters, the samples were divided into group 1 (CR, CLC and CLP) and group 2 (CMR and CCT). Crude polysaccharides of each species were isolated in distilled water at 25-26 C to determine the carbohydrate, sulfate and sugar contents. The extracts were analyzed using chemical methods, IR spectroscopy, and thin-layer chromatography (TLC). The highest yield of total carbohydrate was obtained from CLP (86.99%), while the lowest value (25.83%) obtained from CMR. The extracts of CLC and CLP had a higher sulfate content (14.67-15.78%) than CR (7.40%), CMR (5.54%) and CCT (5.57%). The extracts showed a high substitution of sulfate ester groups, with galactose and glucose as the major sugar component. Difference in sulfate content was because of the individual algal species but not on variety and location. The sulfate was high in the pyrenoid-absent algae (CR, CLC and CLP) while low in the pyrenoid-containing species (CMR and CCT). The presence of pyrenoid showed a negative correlation to the sulfate content (r = -0.866, p<0.05) but not to the carbohydrate content.

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Cultivation of Gracilaria fisheri was conducted in three abandoned shrimp ponds to obtain data of its growth and yield around Pattani Bay, southern Thailand. The experimental ponds were 0.64 (pond 1), 0.32 (pond 2), and 0.36 (pond 3) ha in area. The daily seawater supply naturally depended on the tidal level through an inlet/outlet gate. The seeding were conducted using thalli obtained from another farm by tearing into small fragments and then scattering into the study ponds with an initial density of 92 ± 28 g m^-2. The seaweed fragments were torn and scattered every week until growth was observed. As the results, growth rates of G. fisheri were 9.2 ± 2.8 % day^-1 at maximum and 4.6 ± 3.1 % day^-1 in average before the first harvest at eighth weeks. Algal yields exhibited highest values after a cultivation period of 6 weeks in pond 1 (1,332.9 g m^-2), 8 weeks in pond 2 (3,021.3 g m^-2) and 8 weeks in pond 3 (2,107.3 g m^-2). After half of the thalli in each pond were harvested, the remaining thalli were torn and culture was continued. From 20 weeks of cultivation, the cultivars yielded a total of 7,200 kg fw (pond 1), 14,000 kg fw (pond 2) and 18,700 kg fw (pond 3). Ice-ice phenomena and epiphytic Hypnea cervicornis were observed in pond 1. The cultivators have limited possibilities for expansion of G. fisheri cultivation because of holding on small areas in ponds. The results indicated that it is possible to employ vegetative propagation for the cultivation of G. fisheri in abandoned shrimp ponds, however expansion of the cultivation to open areas in Pattani Bay should be considered.

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The hierarchy of laminarialean algae by molecular phylogenetic analyses has been proposed actively in late years. Here, the recent findings are considered, and the hierarchy on kelp in Japan (Hokkaido, Honshu, Sikoku, Kyushu) is reviewed and 37 species belonging to 7 families are enumerated.

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Niveotectura  pallida (GOULD) is a coralline-eating limpet (Mollusca, Patellogastropoda) which is dominant on the urchin barrens along the coasts of southwestern Hokkaido and northeastern Honshu. This limpet is sometimes eaten by the local residents along the coast; the empty shell was also from shell mounds. As no information about the extractive components was available for N. pallida so far, compositions of free amino acids and ATP related compounds of the sole meat were examined using samples collected from Onagawa, Miyagi Prefecture on the Pacific coast. As the results, little difference was found in general components of the sole meats between N. pallida and an abalone Haliotis madaka; protein accounted for ca 17-18 % of the sole weight in both species. As free amino acids, the sole meat of N. pallida contained arginine and phenylalanine, glycine, alanine and serine and glutamic acid, beside a large amount of taurine. Among the ATP related substances, AMP and ADP accounted for ca 70 %, but the total amount was nearly the half in Haliotis madaka. These features might explain the thin taste of sole meat of N. pallida, which may recommend us the forced or seasoned tasting in its cooking.

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An experimental cultivation of Undaria pinnatifida was carried out in Naruto Strait, Tokushima Prefecture, by crossing male/female gametophytes derived from one zoospore which was obtained from two cultivar lineages (Y and H) from the Naruto area. Four experimental cultivation areas were set, namely the hybrid stock (Y male* H female, Y female* H male) and the true bred (Y male* Y female, H male* H female) gained by the crossing. Morphological variations, daily growth, and color tone were investigated in the experimental cultivation. Based on the morphology of the frond, the hybrid stock inherited the characteristics of the female. The daily growth of the hybrid stock showed the half value of the true bred. This result indicates the potential for cultivar improvement of Undaria pinnatifida by crossing gametophytes derived from one zoospore.

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This paper reports on a new method of natural seeding which make attach embryos released from the natural Sargassum fusiforme community to a nori culture net (as a seeding apparatus) set near a wild S. fusiforme bed. A natural seeding experiment was carried out in the Awata Fishing Port, Eastern Seto Inland Sea, Western Japan and total amount of 7,680 juveniles were obtained from a nori culture net of 4.8 m². The S. fusiforme was cultured in the sea off the port for 152 days, and conse- quently 1.2 kg (wet weight) of S. fusiforme per 1 m of the culture rope were  harvested. Application of nori culture nets is a practical method in natural seeding and raising seedlings of S. fusiforme due to its ease of handling, low cost and labor.

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On seaweed and seagrass, targets of environmental impact assessment (EIA) have been selected from commercial species but rarely from endangered (rare or academically important) species in Japan. However, some recent EIA have paid attention to endangered species such as a green alga Acetabularia and a yellow-green alga Pseudodichotomosiphon because of enlarged concerns on the species diversity. At present, 90 and 25 marine algal species are listed in the Red List (Ministry of the Environment) and the Red Data Book (Fisheries Agency), respectively. On the other hand, 7 prefectures enumerated a total of 107 algal species, while 34 prefectures listed a total of 18 seagrass in their red lists. Further increase of listed species in red lists as well as changes in social conditions may expect much more EIA before starting large civil engineering projects but ecophysiological data on endangered species and monitoring of their populations are needed for accurate and strict assessments.

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The influence of temperature, light intensity, salinity and nutrient concentration (including NO₃^- and PO₄^-) on the early stage of the erect thalli of Cladoszphon okamuranus Tokida were investigated in laboratory culture. The erect thalli formed in the range of 20-30 °C,75-260 μmol m^-2 s^-1, 22-50 ‰, and at nutrient concentrations of 3.1-104 μM NO₃^- and 0.1-15.1 μM PO₄^-. The highest growth was observed at 22.5 °C, 260 μmol m^-2 s^-1, 34 ‰, and at nutrient concentrations of 16.2-44.2 μM NO₃^- and 1.9-6.0 μM PO₄^-. The color of the branches and shape of the thallus was darkened and crumbled with an increase in NO₃^- concentrations of over 56.8 μM and 7.9 μM PO₄^-. The thalli did not grow more than 1cm in length at those nutrient concentrations. From these results, C. okamuranus erect thalli was shown to have minimal adaptability to high nutrient concentrations in enriched seawater media. This is the first report of the affects of nutrient concentrations on the growth of the erect thallus of C. okamuranus.

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