Consumer interest and demand for North Atlantic sourced sea vegetables drives opportunities for aquaculture development in the northeast USA. The unique morphology and desirable culinary traits of the wild narrow-bladed kelp, Saccharina latissima forma angustissima, were successfully translated into a cultivated crop on two geographically distinct open-water farms in Maine, USA. Environmental conditions, growth, and tissue analysis were quantified. Peak meristematic growth rates for blade length occurred from March through April at 2.85 (±0.34) cm day−1. The kelp was harvested from May through June with yields of up to 17 (±4.4) kg m−1 of line and plant density of 330 plants m−1 of line at the Bristol farm and yields of 13.3 (±6.2) kg wet weight m−1 line and a plant density of 400 plants m−1 of line at the Sorrento farm. Second season yields at Sorrento were on average 24.1 (±6.3) kg m−1 of line. Both farms grew significantly narrower blades of f. angustissima than of the sugar kelp, S. latissima. Common garden experiments with the two morphotypes identified trait stability for length and width, while blade ruffles and thickness varied with the environment. Calculations estimating the nutrient bioextraction capability of the cultivated f. angustissima kelp harvested in June reveal N removal of 88.7 kg ha−1 and C removal of 1666.7 kg ha−1 (combined farm site averages). Overall, this unique kelp form has the potential as a new aquaculture crop for the Gulf of Maine while providing several coastal ecosystem services.
Digital library
-
-
Commercial cultivation of Caulerpa lentillifera is now gaining recognition because of the increasing demand in the domestic and international market. Studies on the different culture methods for large scale production of the species in the country are scarce. The present study evaluated the effects of two cultivation methods namely sowing and tray on the growth and biomass production of C. lentillifera cultured in brackishwater pond. For the tray method, propagules were clipped in two 0.75 m x 0.75 m tray and were hung in bamboo frame whereas for the sowing method, propagules were planted directly in the pond substrate with an interval of one meter. The weight gain using the sowing method was significantly higher and could be translated to an average of 1 kg every month of new or harvestable biomass. Specific growth rate of C. lentillifera grown in the substrate was at 3.85% day-1 during the first month and at 2.92% day-1 during the second month and was significantly higher compared to that of stocks grown in trays. High organic load of the soil (substrate) could have improved growth and biomass productivity. The results show that cultivation of C. lentillifera using the sowing method is more effective. This system has significantly contributed to increase in biomass yield. Moreover, this method of farming entails lesser capital outlay without any other material requirements such as bamboos and trays.
-
Bladed Bangiales of the genus Porphyra/Pyropia are highly valuable red algae and extensively farmed in South East Asia. Interest is rising in cultivating species local to the North East Atlantic but the control of the heteromorphic life cycle of native species remains difficult as previous studies reported high inter- and intraspecific variability in required cultivation conditions. Here, working with Porphyra dioica from a UK source population, we conducted a series of experiments investigating the influence of substrate, temperature, photoperiod and light intensity on the development of early life history stages (conchocelis (filamentous sporophyte) and young thalli (gametophyte)). Special focus was the influence of temperature and photoperiod on mature conchocelis to induce a conchospore mass release—the current bottleneck of European Porphyra cultivation. Sporophytes grew largest on an oyster shell substrate and under long day conditions at 18 °C. A decrease in temperature from 18 to 9 °C initiated a mass conchospore release (498 ± 146 spores mL−1 ) from a P. dioica conchocelis culture grown in suspension. Released conchospores germinated into small thalli on nylon ropes, with best growth (7.2 ± 0.9% day−1 ) at low temperatures of 9 °C. Conchospore germination increased with decreasing light intensity but germination success was generally very low (< 5%), indicating the cultivation protocol needs further improvement. Our results reflect the adaptation of P. diocia to seasonal environmental conditions in temperate regions and the importance of these conditions for the successful cultivation. We are the first to describe a mass conchospore release for P. diocia growing in suspension which has important implications for commercial production.
-
To make a preliminary identification of the gracilarioid plant attached to cultivation ropes of Undaria pinnatifida and establish a method of cultivating this plant, the first taxonomic and cultivation studies on this species in Korea were conducted. This gracilarioid plant was identified from its morphological and anatomical features, as Gracilaria chorda. Growth tests using the 10, 20, and 30 cm cuttings of axes of G. chorda were performed twice, from May 3 to August 21, 2002 and from December 15, 2002 to April 3, 2003 in Ihoijin aquafarm, Hoijin, Jangheung, Jeollanamdo, Korea. In the first growing test, the thallus length of the 10, 20, and 30 cm cuttings increased twelve-fold, ten-fold, and seven-fold; the wet weight increased 81-fold, 60-fold, and 41-fold; the numbers of more than 10 cm-long branches increased 3.8-fold, 5.2-fold, and 6.1-fold, respectively. In the second growth test, the thallus length of the 10, 20, and 30 cm cuttings increased seven-fold, 5.5-fold, and four-fold; the wet weight increased 81-fold, 53-fold and 36-fold; the number of branches increased 3.8-fold, 7.3-fold, and 6.6-fold, respectively. The cultivation of G. chorda by vegetative regeneration using cuttings of thallus axes was successful for the first time in Korea.
-
A culture system for the commercial production of the seaweed Gracilaria parvispora using shrimp-farm effluents for fertilization and floating cage-culture for grow-out has been developed on Molokai, HI. This two-phase system produces high-quality products for direct human consumption. The mean relative growth rates (RGRs) of effluent-enriched thalli in the cage system ranged from 8.8% to 10.4% day−1, a significant increase over the growth (4.6% day−1) of thalli fertilized with inorganic fertilizer. Thalli were also grown directly in the effluent ditch, where mean growth rates of 4.7% day−1 were obtained, less than in cage-culture. In the cage-culture system, thallus nitrogen content declined without fertilization. Effluent-enriched thalli grown in the cages steadily declined in nitrogen content, to about 1%, and their C:N ratios increased to between 20 and 30. However, when nitrogen-depleted thalli were transferred to the effluent ditch for enrichment, N content rapidly increased over 5 days to approximately 3%, with a C:N ratio near 10. Benefits of this two-phase polyculture system include enhanced growth of G. parvispora and the use of effluent from commercial shrimp farms as a resource.
-
Gracilaria edulis. a major Indian agarophyte. has been successfully cultivated in an experimental scale from spores at sea off Narakkal, Kochi. Artificial objects like noating roft. nylon ropes and net pieces were provided in the open sea for collect ion of spores of GracUaria edulis. They were allowed to grow to mature size of 30 cm. After 76 days of culture period, fully grown healthy plants of Gracilaria edulis were harvested from the nylon rope by hand pruning. Further growth was much faster. A total yield of 7.220 kg plants was obtained during 122 days of the culture period. The work has resullcd in the successful cultivation of the species from the east coast to a coastal area of the west coast, Narakkal, and also in the identification of a fertile culture ground (open sea off Narakkal. Kechi) along the Kerala coast during favourable period of growth.
-
This work investigates the feasibility of growing marine microalgae Nannochloropsis oculata in a mix of seawater and saline produced water obtained during oil & gas extraction, supplemented with liquid digestate from anaerobic digestion process as source of nutrients. In particular, three-stage cultures were conducted by varying the produced water loading in the culture media (from 0 up to 50% v/v), supplemented with 5% v/v of digestate and seawater. Growth parameters as well as nitrogen (ammonium) and organic carbon (expressed as chemical oxygen demand) removal efficiencies were monitored. Results revealed that N. oculata is perfectly able to grow in a seawater containing produced water from 10 up to 30% v/v. A slower growth was observed for 40 and 50% v/v of produced water, because of the salinity higher than 60 g·L−1. Maximal growth rates obtained were 0.35, 0.27 and 0.16 day−1, with a maximal optical density of 6.3, 5.2 and 3.2 for 10, 20 and 30% v/v of produced water, respectively. Nannochloropsis oculata showed better removal efficiencies for ammonium nitrogen (around 100%) than for organic carbon (approximately 40% after one step of acclimation), regardless of the produced water loading, most chemical oxygen demand being volatilized and/or degraded by bacteria during the first two days of a culture. Regardless of the loading, > 90% of iron brought by produced water and digestate was pre- cipitated and/or assimilated/adsorbed by N. oculata.
-
Over the past decade, the large-scale cultivation of seaweed Gracilaria has expanded rapidly in the Chinese coastal waters. The production of Gracilaria increased from 50,536 tons (t, dry weight) in 2003 to 114,722 t in 2010. The production of the seaweed ranks third only to kelps Saccharina (formerly referred to as Laminaria) and Undaria in China. Nan'ao located in Shantou City, Guangdong Province has been successfully developed as one of the major cultivation bases of Gracilaria lemaneiformis at an industrial scale in South China since 2000, and the farmed area increased by 11,538-fold from 0.13 ha in 2000 to 1500 ha in 2011. From lab-scale study to field industrial practice, it has been documented that Gracilaria cultivation is beneficial in environmental improvements such as mitigating eutrophication, controlling harmful algal blooms, maintaining healthy mariculture systems, and sequestrating CO2. Gracilaria may significantly remediate contaminants in mariculture ecosystems and improve the water environment, and its cultivation provides a new approach to coastal environmental improvement in China and the world.
-
This work evaluated the use of effluent from a marine shrimp biofloc rearing system to cultivate the green seaweed Ulva. First, the growth of two Ulva species, U. ohnoi and U. fasciata, was evaluated. Second, the best-performing species was cultivated under two different stocking densities (2 g L-1 and 4 g L-1) to evaluate both growth and nutrient uptake rates, considering total ammonia nitrogen, nitrate, and orthophosphate. In both cases, environmental variables were monitored, and the cultivation medium, consisting of 25% biofloc water and 75% seawater, was exchanged weekly. U. ohnoi grew significantly better, considering all variables evaluated (p<0.05). The smaller stocking density produced a higher specific growth rate (p<0.05). Yield, however, was unaffected (p≥0.05). No significant differences in the nutrient uptake rates were observed (p≥0.05). Overall, this work highlights the importance of species selection for seaweed destined for aquaculture. Additionally, it also optimizes the cultivation of seaweeds, specifically U. ohnoi, using effluent from biofloc systems.
-
The Brunei–Indonesia–Malaysia–Philippines East Asia Growth Area (BIMP-EAGA) is located within the Coral Triangle, known to have the world’s richest biodiversity in marine flora and fauna. This region lies within the 10° N and 10° S of the Equator where natural populations of both Kappaphycus and Eucheuma grow luxuriantly and abundantly. It is in this same region where commercial cultivation of Kappaphycus and Eucheuma began in the Philippines around the mid-1960s. Commercial farming of Kappaphycus (which was originally called Eucheuma) was successful in the Philippines from the early 1970s, after which the technology was transferred to Indonesia and Malaysia in the late 1970s. No seaweed cultivation has been reported in Brunei. At present, carrageenophytes are cultivated in sub-tropical to tropical countries circumferentially around the globe within the 10° N and S of the Equator. However, their combined production is still low as compared to Indonesia, the Philippines, and Malaysia. Notably, few improvements in farming techniques have been made since its first introduction. Some of the major improvements were the introduction of deep-water farming using hanging long lines, multiple rafts, and spider webs in the Philippines; the use of short and long ‘loops’, instead of plastic ‘tie-tie’ in Indonesia; and mechanization in harvesting and use of solar “greenhouse” drying in Malaysia. Commercial cultivation of tropical red seaweeds in the BIMP-EAGA region is dominated by Kappaphycus and Eucheuma (carrageenophytes) and Gracilaria (agarophytes) and the area became the major region for the production of carageenophytes and agarophytes globally. In particular, Indonesia is a major center for the production of Gracilaria. There is an increasing demand for other agarophytes/carrageenophytes in the international market such as Gelidium spp., Pterocladia spp., Porphyroglossum sp., and Ptilophora sp. for paper and ethanol production in Indonesia and Malaysia, and Halymenia for phycoerythrin pigments in the Philippines currently pursued in an experimental stage. A summary of the present status, problems, sustainability, and challenges for the cultivation of tropical red seaweeds in the BIMP-EAGA region are discussed in this paper.
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.