Effects of a commercial extract of the brown alga Ascophyllum nodosum on the biomass production of Kappaphycus alvarezii (Doty) Doty ex P. C. Silva and its carrageenan yield and gel quality cultivated in Brazil

Despite of its success, the carrageenan industry has had to cope with difficulties due to epiphyte infestations and diseases known as ice-ice. Some promising results in respect of biomass production, carrageenan yield, and protection epiphytes were obtained using a powdered extract of the brown alga Ascophyllum nodosum in Kappaphycus alvarezii seedling production. This study focused on the effects of the A. nodosum extract on the treatment of K. alvarezii cultivated on commercial floating rafts not only to evaluate improvements demonstrated in vitro but also the effects on the quality of the carrageenan. The seedlings were treated in an A. nodosum extract solution and placed alongside their controls on commercial floating rafts using the tubular net technique. Daily growth rate, carrageenan yield, gel strength, and gel viscosity were obtained over 20 and/or 40 days. After 20 days, daily growth rates showed no significant difference (p?=?0.44), while the carrageenan yield was higher in samples that were treated with the A. nodosum solution (p?<?0.001). After 40 days, both daily growth rate (p?=?000.7) and carrageenan yield (p?=?0.009) were higher in treated samples; however, gel strength was higher in control samples (p?=?0.03) as viscosity was also highest in the samples which had not been treated (p?<?0.001). The use of the A. nodosum extract treatment on the cultivation in situ of K. alvarezii was positive since after 40 days when the daily growth rate and carrageenan yield increased. In spite of the negative effect on the quality of the semi-refined carrageenan, the values were within commercial standards.     

Temporal variation of the growth, carrageenan yield and quality of Kappaphycus alvarezii (Rhodophyta, Gigartinales) cultivated at Sepetiba bay, southeastern Brazilian coast

Kappaphycus alvarezii commercial cultivation is increasing along Brazilian coast. After 2008, more than 30 farms were established at Rio de Janeiro state in Sepetiba and Ilha Grande bays. Each farm has about ten floating rafts corresponding to near 900 m of cultivation line. Understanding the effect of the environmental factors on the growth and carrageenan yield and quality of the target algae in commercial farms will subsidize the establishment of efficient management activities to be used in the farms. In this sense, the temporal variation of the K. alvarezii daily growth rate, productivity, carrageenan yield, and quality (viscosity and gel strength) were analyzed using the seedlings cultivated in the largest Brazilian commercial cultivation at Sepetiba Bay. The daily growth rate, productivity, and carrageenan yield and quality were within the commercial requirement desirable for commercial crops. The main factors that caused the breakage of the floating rafts and consequently diminished the productivity are the storms. Water temperature and salinity were the other factors that influenced the daily growth rate and carrageenan yield and quality.     

Evaluation of growth rate and semi‐refined carrageenan properties of tissue‐cultured Kappaphycus alvarezii (Rhodophyta,Gigartinales)

This study aimed to evaluate and compare the quality of κ‐carrageenan obtained from tissue‐cultured and field‐cultured Kappaphycus alvarezii. Carrageenan properties including yield, viscosity, gel strength and sulfate content were studied. After 60 days of cultivation, tissue‐cultured K. alvarezii showed a higher growth rate (6.3 ± 0.01% day^?1) than field‐cultured seedlings (3.4 ± 0.3% day^?1). The obtained carrageenan yield from tissue‐cultured (67.3 ± 16.4%) was higher than field‐cultured K. alvarezii (51.5 ± 21.0%). Gel viscosity of carrageenans from tissue‐cultured K. alvarezii (1280.0 ± 25.0 cP) was found significantly higher than field‐cultured samples (87.8 ± 20.9 cP). The 1.5% gel solution of tissue‐cultured and field‐cultured K. alvarezii exhibited gel strengths of 703.5 ± 14.1 and 288.3 ± 19.3 g cm^?2, respectively. The average sulfate content of carrageenans was found to be significantly different between tissue‐cultured and field‐cultured K. alvarezii with 34.2 ± 10.9 and 7.5 ± 6.7%, respectively. Tissue culture is recommended to produce high quality seedlings by providing optimized culture conditions to the seaweed. This approach can serve as an alternative way to solve the seedling shortage problems currently faced by the seaweed industry.     

Investigation of the application of Acadian Marine Plant Extract Powder (AMPEP) to enhance the growth, phenolic content, free radical scavenging, and iron chelating activities of Kappaphycus Doty (Solieriaceae, Gigartinales, Rhodophyta)

An optimization study on concentration (viz. 0.01, 0.1, and 1.0 g L^?1) and dipping time (i.e., 30 and 60 min) was conducted on three different color morphotypes (i.e., reddish brown, yellowish brown and purple) of the commercial carrageenophyte Kappaphycus alvarezii (Doty) Doty. The study tested the efficacy of Acadian Marine Plant Extract Powder (AMPEP) on the growth rate and occurrence of macro-epiphytes from August to November, representing the wet season of the Philippines. The optimum concentration and dipping time were obtained at 0.1 g L^?1 and 30 min, respectively. These optimum parameters were then further verified in a commercial nursery using the yellowish brown morphotype. In another experiment, K. alvarezii (tambalang purple morphotype) and Kappaphycus striatum (Schmitz) Doty (sacol green morphotype) with, and without, AMPEP dippings were tested for their total phenolic content, free radical scavenging and iron chelating activities. Seaweed dipped in AMPEP demonstrated higher growth rates than the control. Lower concentrations (i.e., 0.01-0.1 g L^?1) and shorter dipping time (e.g., 30 min) produced higher growth rates than the highest concentration (1.0 g L^?1) and longer (60 min) dipping time. The presence of macro-epiphytes such as filamentous Ulva did not adversely affect the robust growth of the three color morphotypes of K. alvarezii. The lowest and highest growth rates obtained in a commercial seaweed nursery using the optimum concentration and dipping time of AMPEP were observed in July and January with 0.8% and 6.7% day^?1, respectively. The antioxidant content of K. alvarezii (tambalang purple) and K. striatum (sacol green) responded differently to AMPEP dipping. The changes in total antioxidant activity followed almost the same trend as in phenolic content, in both K. alvarezii (tambalang purple) and K. striatum (sacol green), whereas, the iron chelating ability of both seaweeds with and without AMPEP dipping varied monthly. The results obtained for the use of AMPEP dips for commercial Kappaphycus cultivation demonstrated an effective management tool for improved farming protocols.     

Extract powder from the brown alga Ascophyllum nodosum (Linnaeus) Le Jolis (AMPEP): a “vaccine-like” effect on Kappaphycus alvarezii (Doty) Doty ex P.C. Silva

The benefits of using Acadian Marine Plant Extract Powder (AMPEP), obtained from the brown algae Ascophyllum nodosum, for improving growth of the red alga Kappaphycus alvarezii has been demonstrated by authors in the Philippines and Brazil, particularly for increasing daily growth rate and mitigation of epiphytes. However, the processes which occur have not been discussed. This study examined in vitro the relationship between those red algal defense mechanisms and K. alvarezii responses using AMPEP treatments. The administration of the extract reduced the effects of the oxidative burst (production of hydrogen peroxide) which may be extremely aggressive for an individual and its epiphyte. The bleaching of the non-corticated portions of Polysiphonia subtilissima thalli that were cultivated as simulated epiphytes with AMPEP samples confirmed that the reaction was evident in which AMPEP protected K. alvarezii from the hydrogen peroxide effects. It is proposed that the use of the brown seaweed powder AMPEP acts as a potential vaccine, eliciting activation of the red seaweed K. alvarezii natural defenses against pathogens and ameliorating the negative effects of long-term exposure to oxidative bursts.     

Direct formation of axes in new plantlets of <Emphasis Type="Italic">Kappaphycus alvarezii</Emphasis> (Doty) Doty,as influenced by the use of AMPEP K<Superscript>+</Superscript>, spindle inhibitors,and plant growth hormones

In order to induce the direct formation of erect dark brown vegetative shoots of Kappahycus alvarezii, under micro-propagation conditions, the agricultural bio-stimulant “Acadian Marine Plant Extract Powder” (or AMPEP) K⁺ (a Canadian commercial extract of the brown seaweed Ascophyllum nodosum with enhanced levels of potassium) was used singly or in combination with colchicine or oryzalin at different concentrations plus (synthetic) plant growth regulators (i.e., PGR, IAA, and kinetin) over 45 days of incubation. Amongst the treatments tested, 5 mg L^?1 AMPEP K⁺ with PGR produced the longest direct axis shoots (9.6 ± 0.33 mm), followed by 0.1 mg L^?1 AMPEP K⁺ + 1.0 mg L^?1 oryzalin with PGR (8.7 ± 0.00 mm), 10 mg L^?1 AMPEP K⁺ + 0.5 mg L^?1 colchicine with PGR (8.6 ± 1.20 mm), and 0.5 mg AMPEP K⁺ only (5.3 ± 1.8 mm). The shortest, direct axis shoots measured were the following: 8.3 ± 0.33 mm with 0.1, 1 and 10 mg L^?1 AMPEP K⁺ with PGR, 6.0 ± 0.58 mm with 0.5 mg L^?1 AMPEP K⁺ + 0.1 mg L^?1 oryzalin with PGR, 5.3 ± 0.89 mm with 0.5 mg L^?1 AMPEP K⁺ + 0.1 mg L^?1 colchicine with PGR, and finally, 2.7 ± 0.33 mm with 0.1 mg L^?1 AMPEP K⁺ only. The percentage of direct shoots formed ranged from 93 to 100 % and 87 to 100 % in AMPEP K⁺ with PGR and AMPEP K⁺ only, respectively, while 62–100 % and 87–100 % were observed in AMPEP K⁺ + colchicine with PGR and AMPEP K⁺ + oryzalin with PGR, respectively. The use of AMPEP K⁺ with the PGR resulted in the longest and highest percentage formation of direct axis shoots. These observations, taken together, suggested the efficacy of AMPEP K⁺ used as a protocol to induce direct, erect shoots for the micro-propagation of K. alvarezii plantlets under laboratory conditions.     

Does biofouling influence <Emphasis Type="Italic">Kappaphycus alvarezii</Emphasis> (Doty) Doty ex Silva farming production in Brazil?

The commercial cultivation of Kappaphycus alvarezii is the main source of raw material for the carrageenan industry. Brazilian commercial farming uses floating rafts that serve as substrata for fouling organisms that may affect production of the carrageenophyte seedlings. The aim of this work was to identify and quantify the biofouling on floating rafts at Sepetiba Bay, Rio de Janeiro State (23° 02′ 25″ S and 43° 53′ 39″ W), and to evaluate seedling damage caused by epibionts and endobionts. Samples were collected from August 2006 to August 2007. In each assessment, organisms contained in random sampling areas of 18 quadrats of 0.10 m² (n = 18) were removed from floating rafts. K. alvarezii seedling samples were collected to verify the presence of epibionts or endobionts (n = 30). Twenty-four taxa belonging to seven groups of animals and three groups of seaweed were found. The percentage occurrence estimated 13 dominant organisms and amphipod tubes: e.g., Chondracanthus tedii, Cladophora vagabunda, Gracilariopsis tenuifrons, Hypnea spinella, Hypnea musciformis, Hincksia mitchelliae, Spyridia spp., Ulva spp., Bowerbankia sp., Bugula neritina, Botryllus sp., Haplosclerida sp., and Perna perna. Richness, equitability, diversity, and total biomass varied significantly during the study period (p < 0.001). There was a tendency for higher biomass values in August 2007. After 6 months, epibionts (i.e., Chlorophyta, Rhodophyta, Chordata, Cnidaria and Ectoprocta) were found on K. alvarezii seedlings. Endobionts were not found in this study. The biofouling biomass was not found to have a significant effect on K. alvarezii daily growth rate, carrageenan yield, or quality (gel strength and viscosity; p > 0.05).     

Optimization of culture conditions for the direct regeneration of Kappaphycus alvarezii (Rhodophyta,Solieriaceae)

Cultivation of seaweeds on a commercial scale requires a large number of propagules with desirable phenotypic traits which include high growth rates and resistance to diseases. Seaweed micropropagation can be considered as one of the best methods to provide a large amount of seedlings for commercial cultivation. This study was carried out to optimize the parameters known to affect the growth of Kappaphycus alvarezii in vitro and subsequently improve the production of seedlings through micropropagation. Suitability of media, concentration of phytoregulators, types and concentration of fertilizers, culture density, light intensity, interval of aeration activity, salinity, and pH were found to be critical factors for the growth of K. alvarezii. The optimum condition for direct regeneration of K. alvarezii in a culture vessel was found to be cultivation of explants in Provasoli's enriched seawater (PES) media supplemented with 2.5 mg L^?1 6-benzylaminopurine (BAP), 1.0 mg L^?1 indole-3-acetic acid (IAA), and 3.0 mg L^?1 natural seaweed extract (NSE) with culture density of 0.4 %?w/v, under light intensity of 75 μmol photons m^?2 s^?1, continuous aeration of 30.0 L h^?1, salinity of 30.0 ppt, and pH 7.5. An airlift photobioreactor was constructed for the mass propagation of K. alvarezii explants with optimum culture conditions obtained from the study. The optimum growth rates of the K. alvarezii explants in culture vessels (5.5 % day^?1) and photobioreactor (6.5 % day^?1) were found to be higher than the growth rate observed in field trials in the open sea (3.5 % day^?1). The information compiled during the course of this study will be of utility to commercial seaweed cultivators.     

Effects of improved post-harvest handling on the chemical constituents and quality of carrageenan in red alga,Kappaphycus alvarezii Doty

Red alga Kappaphycus alvarezii Doty is an important commercial species widely cultivated in southeast Asian countries for its polysaccharide, kappa-carrageenan. Common post-harvest handling technique involves sun-drying of harvested seaweed on platforms at the farms. Quantity and quality of carrageenan varies depending on the duration and care taken during the post-harvest handling of the raw seaweed. In this study, dynamics of moisture content, water activity index (aw), carrageenan yield, and carrageenan quality were investigated by subjecting the seaweed to three post-harvest methods: (1) freeze-drying (FD), (2) shade-drying (SD), and (3) direct sun-drying (DSD). Seaweed dried under FD and SD produced high yield (56–58 %), superior gel strength (1,454–1,424 g cm^?2), high viscosity (57–58 cPs), and low syneresis (15–17 %). But, carrageenan extracted from DSD seaweed gave 28 % lower yield, 38 % lower gel strength, 27 % lower viscosity, and 8–9 % higher syneresis. In addition, gelling temperature and melting temperature of the DSD carrageenan were lower by 4 and 9 °C, respectively. Molecular size analyses of carrageenan extracted from seaweed dried under FD and SD contained carrageenan of 700 KDa (80 %) and 200 KDa (4–10 %). However, carrageenan extracted from DSD seaweed contained smaller carrageenan molecules, 460 KDa (55 %), 210 KDa (25 %), and <100 KDa (20 %). Further, scanning electron microscope images illustrated the severe effects of DSD on the morphology of seaweed cells. Therefore, SD technique was found to be the best post-harvest processing technique that gave quality carrageenan in a high quantity. Due to its simplicity and low cost, it is a practical approach to be practiced in southeast Asian countries.     

The effects of selected cultivation conditions on the carrageenan characteristics of <Emphasis Type="Italic">Kappaphycus alvarezii</Emphasis> (Rhodophyta,Solieriaceae) in Ubatuba Bay,São Paulo,Brazil

The yield and the quality of carrageenan depend, among other things, on the cultivar or strain and on the cultivation and processing techniques. This work presents carrageenan yields and some properties of Kappaphycus alvarezii under selected cultivation conditions i.e. cultivation period, depth and planting density. Growth rates (GR) ranged from 5.2–7.2% day⁻¹, with the highest GR at 28 days, at 0–0.5 m depth, and planting density of 12 and 8.4 plants m⁻². Highest productivity was observed in samples after 44 and 59 day cultivation period, which were grown at 0–0.5 m depth, and a planting density of 24 plants m⁻². Carrageenan yields, iota fraction, viscosity, molecular weight and gel strength were measured. A cultivation period of 28 days during the winter had a significant higher carrageenan yield, while samples from 59 days showed a significantly higher iota fraction. Carrageenan also presented an increasing molecular weight under longer cultivation periods. A similar trend was observed for viscosity and gel strength. All samples cultivated in Brazil gave higher values when compared to a K. alvarezii commercial reference sample, with the exception of carrageenan yield values, which were lower in this study. Taking into account all parameters, the culture condition which provided the best carrageenan from a commercial perspective were 45 days of cultivation, growing at the surface, with a planting density of 12 plants m⁻². Considering that this study was performed in the least favorable season (winter), these results indicate that the site is suitable for the implementation of commercial cultivation.     

Seasonal variation in growth and carrageenan yield in cultivated Kappaphycus alvarezii (Doty) Doty on the coastal waters of Ramanathapuram district,Tamil Nadu

Kappaphycus alvarezii, a kappa carrageenan yielding red seaweed, was cultivated in Indian subtropical waters on the Palk Bay side of Bay of Bengal in Ramanathapuram district, Tamil Nadu, at three different sites: Vedalai, Munaikadu, and Thonithurai, for 1 year from April 2011 to March 2012. The maximum crop yields of 416 ± 51 and 550 ± 41 FW raft^?1 were recorded at Vedalai and Munaikadu, respectively, in December 2011, whereas a maximum of 326 ± 49 FW raft^?1 was recorded at Thonithurai in April 2011. Similarly, the maximum daily growth rates (DGRs) of 4.30 ± 0.51 % and 4.92 ± 0.40 % were obtained at Vedalai and Munaikadu, respectively, in December 2011, and 3.76 ± 0.48 % was recorded at Thonithurai in April 2011. Variations in environmental parameters like seawater temperature, salinity, nitrate, and phosphate were found to influence the growth of the seaweed. The maximum carrageenan content as a percentage of dry weight was 29.30 ± 0.61 % (Vedalai), 31.00 ± 0.71 % (Munaikadu), and 29.10 ± 1.12 % (Thonithurai) in March 2012. The data on moisture content (%), clean anhydrous weed/salt ratio, and carrageenan yield obtained in this study fulfilled those of international standards. Further, the results indicated that large-scale cultivation by either NGOs or self-help groups (SHGs) may be taken up along the coastal waters for the benefit of the poverty-stricken coastal people as their livelihood, as the growth rate obtained in this study compared well with that recommended for commercial cultivation elsewhere.     

<Emphasis Type="Italic">Kappaphycus alvarezii</Emphasis> (Rhodophyta,Areschougiaceae) cultivated in subtropical waters in Southern Brazil

Four strains of Kappaphycus alvarezii were cultivated in the subtropical waters of Florianópolis, Santa Catarina State, Brazil (27°29′19′′ S/48°32′28′′ W), from February 2009 to February 2010. Seaweeds were cultivated on floating raft near of mussel farms. Salinity ranged from 29 to 36 psu and temperature from 17.1 to 28.5°C. Higher growth rates (5.12–4.29% day⁻¹) were measured in summer and autumn, showing a positive correlation between growth rate and water temperature. Lower growth rates (0.54–0.32% day⁻¹) occurred in winter, resulted mainly by biomass loss. Significant differences were observed among the strains in spring and the brown tetrasporophytic strain was the only one which failed to recover, being excluded of the experiments. The effect of cultivation periods (36, 42, and 97 days) on carrageenan yield, gel strength, and viscosity were analyzed. Carrageenan yields were higher for plants kept 42 days in the sea (28%), against 25% for 36 and 97 days. There were no significant differences in carrageenan yield among the strains analyzed. Viscosity increased with the increase of cultivation period, while gel strength seemed to vary at random. Tetrasporangia and cystocarps were not observed, and lost fragments did not attach outside the raft. In general, dissolved inorganic nitrogen concentration decreased around the cultivation area as compared to the mussel farm. Results show that cultivation of K. alvarezii is technically feasible in subtropical waters and can be associated with local mussel farms, mitigating the eutrophication and, eventually, increasing the economic return of the farmers.     

Kappaphycus malesianus sp. nov.: a new species of Kappaphycus (Gigartinales,Rhodophyta) from Southeast Asia

A new species, Kappaphycus malesianus, is established as a new member of the genus Kappaphycus. Locally known as the “Aring-aring” variety by farmers in Malaysia and the Philippines, this variety has been commercially cultivated, often together with Kappaphycus alvarezii due to the similarities in morphology. Despite also producing kappa-carrageenan, the lower biomass of the K. malesianus when mixed with K. alvarezii ultimately affects the carrageenan yield. Morphological observations, on both wild and cultivated plants, coupled with molecular data have shown K. malesianus to be genetically distinct from its Kappaphycus congeners. The present study describes the morphology and anatomy of this new species as supported by DNA data, with additional morphological features for distinguishing between commercial Kappaphycus cultivars.     

Effect of epiphyte infection on physical and chemical properties of carrageenan produced by Kappaphycus alvarezii Doty (Soliericeae,Gigartinales, Rhodophyta)

Epiphytism of filamentous red algae is a serious problem in Kappaphycus farms in the Philippines, Indonesia, Malaysia, and Tanzania. The causative organism of epiphyte outbreak has been identified as Neosiphonia apiculata (Hollenberg) Masuda and Kogame, but its actual effect on carrageenan quality has not yet been established. Therefore, yield and quality of carrageenan from healthy and infected specimens were examined. Infected specimens showed 20.5?±?2.5 % DW lower carrageenan yield compared with the healthy seaweed (65.5?±?4.2 % DW). Infected specimens also had a higher phenolic and fatty acid content, compared with healthy specimens. The carrageenan from the infected seaweed showed 74.5?±?2.8 % lower viscosity, 52.6?±?3.6 % lower gel strength, 22.9?±?1.5 % higher syneresis, and 5 °C higher melting temperature as compared with carrageenan from healthy specimens. FTIR and ¹³C-NMR analysis of carrageenan from infected seaweed did not show any differences in their functionality or carbon atom chemical shift as compared with healthy and standard k-carrageenan. However, size exclusion chromatography showed the infected carrageenan molecular size to be 80 kDa as compared with 800 kDa for the healthy and standard k-carrageenan. These findings prove that infection of Kappaphycus by the filamentous red algae epiphyte, N. apiculata, reduces carrageenan molecular size and affects the physical properties of the carrageenan.     

Impact of AMPEP on the growth and occurrence of epiphytic Neosiphonia infestation on two varieties of commercially cultivated Kappaphycus alvarezii grown at different depths in the Philippines

Two varieties of the carrageenophyte Kappaphycus alvarezii (Tungawan, TUNG; and Giant tambalang, GTAM) from Zamboanga Sibugay, Philippines were used to test the efficacy of Acadian Marine Plant Extract Powder (AMPEP) as source of nutrients for growth, and to determine if applications had any effect on the percent occurrence of an epiphytic infestation of the red alga Neosiphonia sp. at four different depths in the sea. Results showed that the use of AMPEP significantly (P < 0.05) increased the growth rate of both Kappaphycus varieties tested but decreased the percent occurrence of Neosiphonia sp. The percent occurrence of Neosiphonia sp. infection (6–50% at all depths) of both Kappaphycus varieties with AMPEP treatment was significantly lower than the controls (i.e., 10–75% at all depths). Both the growth rate of the cultivated seaweed and the percent occurrence of the epiphytes decreased as the cultivation depth increased. Plants dipped in AMPEP and suspended at the surface had the highest growth rates (i.e., 4.1%, TUNG; 3.1%, GTAM) after 45 days; those without AMPEP dipping had the highest percent occurrence of Neosiphonia infection (viz. 70–75%). The occurrence of Neosiphonia infestation was found to be correlated with changes in irradiance and salinity at the depths observed. The results suggested that both varieties of K. alvarezii used in this study have the fastest growth rate when grown immediately at the water surface. However, in order to minimize damage caused by the occurrence of epiphytic Neosiphonia, K. alvarezii should be grown within a depth range of 50–100 cm. These observations are important for the improved management of Kappaphycus for commercial farming. Furthermore, the use of AMPEP treatments for enhancement of growth and reduction deleterious Neosiphonia sp. infections is encouraging.     

Growth rate,carrageenan yield and gel properties of culturedkappa-carrageenan producing red algaKappaphycus alvarezzi (Doty) Doty in the subtropical waters of Shikoku,Japan

Kappaphycus alvarezii (Doty) Doty from the Philippines was grown in the subtropical waters of Shikoku Is., Japan (33°2635 N, 133°2500 E). The growth rate, carrageenan yield, viscosity and gel strength were compared to values for plants cultured in the Philippines and between spring-summer, autumn-winter and winter periods in Japan. Maximum daily growth rates up to 8% occurred in Japan in October to November (autumn) while die-back occurred in winter due to low seawater temperature (15 °C). The average growth rate (ca 5%) in spring-summer to autumn was comparable to that in the Philippines. During the winter (December), the daily growth rate was approximately 1%. Gel strength, determined in a 1.5% solution in both water and 0.2% KCl, was 850 g cm^-2 and 2000 g cm^-2, respectively. Sol viscosity was 890 cP at 75 ° C. These values are quite similar to values obtained in the Philippines.     

Social upliftment of coastal fisher women through seaweed (Kappaphycus alvarezii (Doty) Doty) farming in Tamil Nadu,India

A growth study of Kappaphycus alvarezii seaweed cultivation was conducted using the raft method and by implementing best practices in three coastal districts: Ramanathapuram, Pudukkottai, and Tuticorin in Tamil Nadu, India. From the growth data, economics and self-help group (SHG) per individual income were also calculated. Cultivation was conducted by brown monotype using raft method. The study was conducted from January 2008 to December 2010. The maximum average freshweed per raft yield was 260.98?±?3.45 kg (in 2010) in Ramanathapuram and the lowest was 172.89?±?2.77 kg (in 2009) in Pudukkottai after 45 days. The maximum average daily growth rate (ADGR) was 3.27 ± 0.41 % (in 2010) in Ramanathapuram and 2.35 ± 0.18 % (in 2009) in Pudukkottai after 45 days. One SHG of five members requires a working capital and total investment of Rs 225,000 (US$4,091). Best practices to get good income were implemented in 2010 in all three districts, and their average approximate income Increased from Rs 35,000 (US$636) to more than 50,000 (US$909) SHG^-1 month^?1. The farming of K. alvarezii by using best practices has brought tremendous social impact to coastal fisher women.     

Growth rate and carrageenan analyses in four strains of <Emphasis Type="Italic">Kappaphycus alvarezii</Emphasis> (Rhodophyta,Gigartinales) farmed in the subtropical waters of São Paulo State,Brazil

Growth rate, semi-refined and refined carrageenan yields, 3,6-anhydrogalactose and sulphate contents, and gel strength were investigated in four strains of Kappaphycus alvarezii (brown, green and red tetrasporophytic strains, and one strain derived from tetraspores progeny, called G11) farmed in subtropical waters of São Paulo State, Brazil. All studied strains showed higher growth rates from February to May, decreasing from July to December. The G11 strain exhibited lower growth rates, but had semi-refined and refined carrageenan yields significantly higher than the others and similar to a commercial sample. A negative correlation between growth rate and semi-refined carrageenan yield was verified for all strains. The brown strain had the lowest content of 3,6-anhydrogalactose, while G11 and green strains showed higher values. No clear pattern of variation and no relationship were observed for sulphate and gel strength. However, all strains presented gel strength values near the one obtained from commercial sample. These results show that the carrageenan extracted from brown, green, red, and G11 strains of K. alvarezii cultured in subtropical waters of São Paulo State, Brazil with commercial potentials.     

In situ variability of carrageenan content and biomass in the cultivated red macroalga <Emphasis Type="Italic">Kappaphycus alvarezii</Emphasis> with an estimation of its carrageenan stock at the scale of the Malasoro Bay (Indonesia) using satellite image processing

The combination of in situ measurements, hydrodynamical modeling, and satellite imagery processing presents a complete tool to improve seaweed culture management. This study measured the evolution of carrageenan content during 1-year period and estimated the biomass of Kappaphycus alvarezii at a bay scale in Malasoro Bay, Indonesia. It allowed the determination of the carrageenan stock at the scale of the bay. The carrageenan content was assessed from different parts, i.e., basal and apical, of the thallus. The biomass from T ₀ (beginning of the cultivation) to T ₄₅ (harvesting time) was determined at two seasons. Satellite image processing was performed to estimate the biomass at bay scale using parcels resulting from a semi-automatic delineation process. As no long-term in situ environmental data existed in the study area, a 3D hydrodynamical model (Model for Application at Regional Scale 3D) was implemented to obtain high-frequency salinity, water temperature, and currents. The high carrageenan yield was obtained from April to September 2015 (54–63%) when temperature ranged from 25 to 30 °C, salinity range from 33.8 to 34.8 psu, and precipitation below 0.5 mm. The biomass at bay scale was estimated at 2590 t with the highest carrageenan stock at 1.8 t ha^?1 in May 2015. The carrageenan yields and quality obtained in this study fulfilled the specification recommended for industry, and the cultivation of K. alvarezii can be carried out at optimal environmental conditions on April–September. The comprehensive approaches used in this study provide information for carrageenan stock and seaweed culture management as an important economic activity to support Indonesian coastal communities.     

Artificial seed production and cultivation of the edible brown alga Sargassum naozhouense Tseng et Lu

Sargassum naozhouense Tseng et Lu is a perennial brown alga found in the coastal area of Leizhou Peninsula, Guangdong, China, and it has considerable commercial potential for further exploitation. To develop a commercial-scale aquaculture of this edible species, the growth, maturation, artificial seeding, and cultivation of this alga and harmful co-existing organisms were investigated from March 2009 to April 2010. In the alga’s natural environment, the receptacles began to form in April and bloomed in May. Artificial cultivation reduced the time required for thalli maturation by at least 1 month. Seedlings were cultured for 1 month in tanks with flowing seawater, until the seedlings had grown to a length of 1.5–2.0 mm. The seedlings were then transferred to a nursery culture ground at sea for an additional 5 months until they reached a mean length of 5 cm. The control of fouling organisms was crucial for establishing a successful seedling culture both indoors and at sea. Afterwards, 45,000 germlings were reared in a grow-out sea area using a full floating raft cultivation system on 2-km-long ropes. The mean yield from this rearing was 1,750 kg wet wt.?km^?1 culture rope during the farming period of 95 days. Adult S. naozhouense has a greater tolerance to high temperatures than other cultivated Sargassum species and can withstand a temperature as high as 33.7 °C. A preliminary commercial cultivation protocol was also established. The results demonstrate the potential to aquaculture S. naozhouense at relatively high seawater temperatures.