The many nutritional benefits reported in seaweeds have increased their demand in the western world for human consumption. In order to supply this demand, it is necessary to cultivate seaweeds both offshore and onshore. Offshore cultivation is highly vulnerable to climate variation. Cultures on land can be operated while essential variables can be controlled (nutrient supply) or partially regulated (light and temperature) providing a more uniform quality and continuous production. In this study, we present the results of pond-culture in a commercial pilot-facility on the Pacific, temperate coast of Mexico, which has been continuously running for 2½ years. Ponds of 100 m3 were seeded with 3 kg/m2 of a previously selected strain of Ulva. Pulse fertilization and a full water exchange were made twice a week. Ponds were fully harvested every 3 weeks and re-seeded with the initial density. Seaweed production showed a bimodal distribution with a strong peak in spring (258–290 g m−2 day−1), a minor peak in autumn, and lower production in summer and much lower in winter (40–85 g m−2 day−1). Highest growth performance occurred when the average temperature remained between 17 and 23°C. This study provides a realistic baseline for annual seaweed production on a commercial pilot-scale aquaculture farm.
Digital library
-
-
We investigated seasonal and within-plant variation in total fatty acids (TFAs) and biomass increase in the tropical brown seaweed Spatoglossum macrodontum which was sampled from Magnetic Island (Queensland, Australia) at monthly intervals over 1 year. In this habitat, S. macrodontum is an annual species with a growth period from June to September where mean biomass changed from 8- to 136-g fresh weight. Although TFA content and fatty acid (FA) composition were not directly correlated to individual plant size, there was clear seasonal variation in TFA content with a peak in July (82.7 mg g−1 dry weight (dw)) followed by a 30 % decline in August and little subsequent variation from September to November (65.9–55.5 mg g−1 dw). The FA profile was rich in polyunsaturated FAs (PUFAs) (39 %); however, there was a change to a higher percentage of saturated FAs (SFAs) (42 %) and reduced PUFA (31 %) as plants reached the end of the growth period. Averaged across sampling periods, TFA content ranged from 77 mg g−1 dw in the tips to 30 mg g−1 dw in the base section. While PUFA content (37–38 %) was similar across sections, the base had less SFAs and a higher content of monounsaturated FAs (MUFAs) (29 %). These results are the first data on the seasonal biomass increase and the temporal and internal variations in FAs for this species with important implications when targeting large brown seaweeds as a source of FAs for nutraceuticals (PUFA(n-3), 21.8 % of TFA) or chemicals (C18:1 (n-9), 17.6 % of TFA)
-
Young plants of S. ilicifolium and S. myricosystum appear in April and May and reach the maximum size in September or October. Alginic acid yield varies with the seasonal growth behaviour of these alginophytes. with maximum yield in July or August. Alginic acid content varies from 22.3 to 30.8% in S. ilieifolium and from 15.9 to 34.5% in S. myriocyslum. Mannitol content ranges from 2 to 5 and 1.3 to 5% in S. jlicifolium and S. myriocysmm respectively. The suitable harv.esting period for getting the maximum yidd of algin ic acid appears to be between July and September.
-
Seasonal variation in growth and biochemical constituents such as protein, carbohydrate and lipid in Hypnea valentiae, Acanthophora spicifera, Laurencia papillosa, Enteromorpha compressa, Ulva lactuca and Caulerpa recemosa were observed for one year from April, 1995 to March 1996. Carrageenan content was estimated from H. valentiae, A. spicifera and L. papillosa. In general, peak growth and biomass of these algae occurred during the period June -August and January - March. The maximum values in these algae varied from 12.5 to 13.2% for protein, 13.0 to 13.3% for carbohydrate and 10.3 to 12.0% for lipid. The yield of phycocolloid recorded 11.3%, 6.0% and 8.1% in H. valentiae, A. spicifera and L. papillosa respectively.
-
Seasonal variations in growth, fruiting and sporulation of Gelidiopsis variabilis (Greville) Schmitz occurring on the Visakhapatnam coast have been described. Only tetrasporophytes and vegetative plants were found in the populations analysed for 21/2 yr and seasonal changes were more marked in the abundance of tetrasporophytcs formation of stichidia and in the spore output than in the stature of the plants. Maximum development of the plants was observed each year between October and January-February and peak reproductive activity from July to September.
-
Seasonal occurrence and reproduction in populations of Hypnea charoides Lamouroux were investigated along two coastal shores, A Ma Wan and Lung Lok Shui, in Tung Ping Chau, N. T., Hong Kong SAR, China, from 1996 to 1999. Annual growth of these populations was initiated in early winter (November-December) and ended in late spring (April-May). Mean length of H. charoides in A Ma Wan was significantly negatively correlated with photoperiod (r = -0.359, n = 38, p < 0.05) and seawater temperature (r = -0.669, n = 38, p < 0.05). Vegetative plants were dominant but relatively high abundance in tetrasporic plants was observed at the end of each growing season. Percentage occurrence of tetrasporic plants was significantly positively correlated with seawater temperature in samples collected at -I m CD (r = 0.635, n = 19, p < 0.05), -2 m CD (r = 0.690, n = 13, p < 0.05) and from drifted populations (r = 0.705, n = 17, p < 0.05), suggesting that increase in seawater temperature might induce tetrasporogenesis of H. charoides in A Ma Wan. Plants in Lung Lok Shui were mostly vegetative but 100% tetrasporic samples were collected at -I m CD during an unusual growth period in October 1998. High abundance of tetrasporic plants was also observed at a depth of -10m CD on 9 April 1998 (97.5%) and 22-Apri11999 (90%). Significantly negative correlation was found in percentage occurrence of vegetative plants at -10 m CD with photoperiod (r = -0.553, n = 14, p < 0.05) and seawater temperature (r = -0.855, n = 8, p < 0.05). Dominance of vegetative and tetrasporic plants and rarity of cystocarpic plants in both A Ma Wan and Lung Lok Shui suggested that the life span of H. charoides might be very short and/or majority of the plants underwent apomeiosis to complete their life cycles in Tung Ping Chau.
-
Seasonal variation in biochemical constituents of S. wightii with reference to yield in alginic acid content has been reported. The lipid content showed a reciprocal relation, while carbohydrate a positive correlation with alginic acid content.
-
Essential micro-nutrients such as manganese, copper, lead and zinc were analysed in three species of Gracilaria for 12 months from August 1994 to July, 1995. Comparative data on the interspecific variation of essential micro-nutrients have been explained. Seasonal variation of the trace element within the species were also analysed. Zinc content was found to be maximum in all the species of Gracilaria. In general, the decreasing trend of essential micro-nutrients was Zn>Pb>Cu>Mn. Manganese and copper content were found to be comparatively higher in G. edulis whereas lead dominated in G. crassa.
-
An year-round experiment was conducted in the culture of Gracilaria edulis by reproductive method in the Gulf of Mannar and Palk Bay, near Mandapam, along the southeast coast of India. The spores liberated on cement blocks were transplanted to Palk Bay in April after 17 days of spore output and nursery rearing. The germlings were transferred to the Gulf of Mannar during August when the size of the plants ranged between 0.3 and 1.9 cm (mean 0.88 cm) with a crop growth rate of 0.011 cm/day. The CGR was more pronounced from October being 0.043 cm/day and increased gradually till harvest reaching a peak value of 0.650 cm/day during March. The harvested plants were young, healthy and sterile. October to March was found to be the most suitable period for cultivation.
-
Seasonal variations in growth, alginic acid and mannitol contents of Sargassum wightii and Turbinaria conoides growing in the Gulf of Mannar near Mandapam have been followed for a period of two and a half years from August 1965 to J a n u a r ~ 1'308. 3Iarl;ed seasonal changes occur in the growth of these two brown algae with a slow growth in the population up to July or -1ugust and a rapid growth from October to December when reproductive receptacles were noticed in both the species. Results obtained on the alginic acid and mannitol contents indicate that these two carbohydrates vary with tile seasonal growth behaviour of the two brown algae investigated. Yield of alginic acid is high during the peak growth and fruiting periods, Mannitol content is at its maximum in the early stages of the growth cycle from May to August and minimum after the initiation of the reproductive receptacles.
Pages
Marine Agronomy Group, CAFNRM, UH-Hilo
200 W. Kawili st., HI 96720, USA
Contact: Marine.Agronomy.Group@gmail.com
Funding for this web portal is provided by the World Wildlife Fund and the University of Hawaii-Hilo.