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Eucheumatoid cultivation is an important alternative livelihood for small-scale farmers in coastal areas in east Malaysia. Over the last 50 years, the same clones of the red eucheumatoid Kappaphycus alvarezii and Kappaphycus striatus have been vegetatively propagated for cultivation resulting in low genetic diversity. This has made the cultivars more vulnerable to pests and diseases, which has been further exacerbated by climate change. There is an urgent need, therefore, to develop new cultivars that are resilient to pests and diseases, as well as environmental change. In this study, wild eucheumatoids were collected from four regions in Semporna, East Malaysia: Kerindingan, Sibuhun, Sebangkat and Omadal. These eucheumatoids were then grown at a commercial seaweed farm in Silungun, Semporna using two methods: i) tie-tie and ii) basket net for 60 days and their performance was evaluated based on growth and survival rates. A higher mean specific growth rate (SGR) was recorded by wild-collected Kappaphycus spp. (2.15 ± 1.90% day−1) and Eucheuma denticulatum (2.83 ± 3.27% day−1) when tie-tie was used. However, survival of the wild-collected eucheumatoids was better with the basket net, which led to a reduction in grazing and prevented detachment from culture lines. Of 212 original individuals, 72 survived throughout the study, despite the prevalence of pests and ice-ice disease. Of these, 46.15% Kappaphycus spp. and 50.75% E. denticulatum survived when cultivated using the basket net and 17.20% Kappaphycus spp. and 30.77% E. denticulatum survived when cultivated using tie-tie. The mean SGR and survival rate were significantly correlated with temperature, salinity, pH, current velocity and rainfall (p < 0.05). The surviving wild-collected Kappaphycus spp. and E. denticulatum have the potential to be developed into new cultivars for possible commercial use. [ABSTRACT FROM AUTHOR]

Indonesia is the second largest producer of seaweed in the world. Different cultivated seaweed commodities may have different production results. This study aimed to determine the effect of cultivation time and different types of seaweed on the total weight and Specific Growth Rate (SGR) of Kappaphycus alvarezii and Eucheuma spinosum cultivated with the long-line method. The study was conducted in one cultivation area, PT. Sea Six Energy, Bali, Indonesia. Data collection was carried out through observations in 2 sites. Every site contained 3 square frame seaweed K. alvarezii and E. spinosum. The sample used in this study was one thallus of seaweed taken randomly from 3 different ris ropes in each square frame. The average weight of thallus, total weight, and specific growth rate were performed in this study. After 51 days, the total weight of K. alvarezii was 1348.5 kg. The total weight of E. spinosum was 1398.7 kg. Both, K. alvarezii (8.4 ± 0.34 %.day-1) and E. spinosum (8.3 ± 0.02 %.day-1) showed higher Spesific Growth Rate (SGR) in the first 2 weeks of planting but not in the last 3 weeks of cultivation. There was no difference in productivity between K. alvarezii and E. spinosum cultivated using the longline method. However, this research showed that the SGR value decreased as cultivation time increased. [ABSTRACT FROM AUTHOR]

In an integrated multitrophic aquaculture (IMTA) system, seaweeds serve as extractive species that utilize excess nutrients, thereby reducing the risk of eutrophication and promoting sustainable aquaculture. However, the use of excessive fish feeds and the resultant faecal waste as nutrient streams can contribute to variations in nitrogen and phosphorus levels (e.g., primarily NH4+ and PO4−3) in the surrounding area and this may impact the physiology of the integrated seaweeds, particularly on how these species take up inorganic nutrients. In this study, the effect of different PO4−3 levels on NH4+ uptake of the three commercially important eucheumatoids Kappaphycus alvarezii, Kappaphycus striatus and Eucheuma denticulatum was examined under laboratory conditions. Seaweed thalli (n = 4) were incubated in seawater media containing 30 µM NH4+, and 0, 0.5, 1.0, 1.5, 3.0 or 5.0 µM PO4−3 for 1 h under a saturating light level of 116 ± 7.13 µmol photons m−2 s−1 inside a temperature-controlled laboratory. Species-specific responses to PO4−3 levels were observed. For K. alvarezii, maximum NH4+ uptake (17.8 ± 1.6 µmol gDW−1 h−1) was observed at 0.5 µM PO4−3 and the uptake rate declined at higher PO4−3 levels. For K. striatus, NH4+ uptake increased with increasing PO4−3 levels, with maximum N uptake (6.35 ± 0.9 µmol gDW−1 h−1) observed at 5.0 µM PO4−3. For E. denticulatum, maximum NH4+ uptake (14.6 ± 1.4 µmol gDW−1 h−1) was observed at 1.0 µM PO4−3. Our results suggest that among the three eucheumatoid species, the NH4+ uptake of K. striatus persists even at high levels of PO4−3. However, our results also showed that K. striatus had the lowest range of NH4+ uptake rates. These results should be taken into consideration when incorporating eucheumatoids in the IMTA system, where PO4−3levels significantly vary in space and time. [ABSTRACT FROM AUTHOR]

Seaweed is the primary source of carrageenan, but it also contains iodine, which can inhibit bacterial activity and growth. The iodine contained in seaweed results from interaction with the marine environment rich in iodine. The research was conducted from June to November 2022 and used iodine from seaweed extraction to test antibacterial activity (Staphylococcus aureus and Salmonella sp). The antibacterial activity test was carried out for 48 hours. The iodine concentration was determined using titration, while the antibacterial activity test used the Disc Diffusion Test. The research showed that Eucheuma spinosum extract contained iodine, 0.38% - 1.22%. The antibacterial activity of seaweed iodine test results revealed an average inhibition zone diameter of 11.5 mm for Staphylococcus aureus and 12 mm for Salmonella sp. This research shows that the iodine in Eucheuma spinosum extract has an inhibitory solid impact on the activity and growth of Staphylococcus aureus and Salmonella sp [ABSTRACT FROM AUTHOR]

Kappaphycus spp. and Eucheuma denticulatum are commercially farmed in the world, notably in tropical countries such as Indonesia, Philippines, and Malaysia. Diseases and pests, particularly ice-ice disease, are the major hurdles in the sustainability of eucheumatoid seaweed culture. In this study, ice-ice disease prevalence in Kappaphycus and Eucheuma farms in Sibutu, Tawi-Tawi, Philippines, was assessed and compared according to species, farm depth, and time. Results revealed that in deep water farms, ice-ice disease prevalence was significantly lower in K. striatus (4.29±0.97%) than in K. alvarezii (10.53±2.64%) in July. In shallow water farms, E. denticulatum had the highest ice-ice prevalence (21.97±1.73%) significantly among the assessed seaweed species during August, and K. alvarezii had the lowest ice-ice disease occurrence (5.43±1.98%) significantly during September. In terms of depth water farm and time comparison, ice-ice disease prevalence (7.41±1.50% - 27.04±4.66%) in deep water (exceeding 2.47±0.16 m during low tide) did not differ significantly from that prevalence (11.35±1.69% - 12.91±1.93%) in shallow water farms (0.61±0.29 m during low tide) across time. This study suggests that ice-ice disease is still a prevalent and persistent problem in eucheumatoid seaweed farming. [ABSTRACT FROM AUTHOR]

Biochar was derived from Eucheuma (EBC) at a temperature of 500 °C and the resulting biochar was modified using NaOH, KOH, NaOH + KOH and HNO3 + HCl. This study investigated the impact of these modifications on the characteristics of the biochar and its effectiveness in adsorbing phenanthrene (Phe) from an aqueous solution. The results indicated that the surface roughness increased, leading to an increase in the specific surface area, and the development of complex pore structure, leading to a decrease in the polarity and increase in hydrophobicity of biochar modified by a mixture of KOH and HNO3 + HCl (EBC-K and EBC-H). The EBC-K and EBC-H samples exhibited superior surface areas (272.76 and 289.60 m2 g−1) and adsorption capabilities for Phe (removal rates of 99.8% and 99.4%). The pseudo-first order, pseudo-second order and intraparticle diffusion Kinetic model demonstrated that the adsorption process is determined by both physicochemical and intra-particle diffusion. The adsorption process was well described by the Langmuir model. The maximum adsorption capacity of EBC-K and EBC-H was increased by approximately 2.4 times compared with the original biochar. Batch adsorption experiments indicated that the removal rate increases with the increase of dosage. Additionally, EBC-H regenerated from n-hexane removed 85.52% of the Phe solution. [ABSTRACT FROM AUTHOR]

The effects of alkali type and pH on the physical properties of carrageenan have been extensively studied. However, their effects on certain characteristics of solid-state properties of carrageenan have not been identified. This research aimed to investigate the effect of alkaline solvent type and pH on the solid physical properties of carrageenan isolated from Eucheuma cottonii. Carrageenan was extracted from the algae using NaOH, KOH, and Ca(OH)2 at pHs of 9, 11, and 13. Based on the results of preliminary characterization, including yield, ash content, pH, sulphate content, viscosity, and gel strength, it was found that all samples followed Food and Agriculture Organization (FAO) specifications. The swelling capacity of carrageenan based on the type of alkali was KOH > NaOH > Ca(OH)2. The FTIR spectra of all samples were in agreement with that of standard carrageenan. The molecular weight (MW) of carrageenan using KOH as the alkali followed the order pH 13 > pH 9 > pH 11, while using NaOH, the order was pH 9 > pH 13 > pH 11, and while using Ca(OH)2, the order was pH 13 > pH 9 > pH 11. The results of the solid-state physical characterization of carrageenan with the highest MW in each type of alkali showed that the morphology of carrageenan using Ca(OH)2 has a cubic shape and is more crystal-like. The order of crystallinity of carrageenan using different types of alkali was Ca(OH)2 (14.44%) > NaOH (9.80%) > KOH (7.91%), while the order of density was Ca(OH)2 > KOH > NaOH. The order of solid fraction (SF) of the carrageenan was KOH > Ca(OH)2 > NaOH, while the tensile strength when using KOH was 1.17, when using NaOH it was 0.08, and while using Ca(OH)2, it was 0.05. The bonding index (BI) of carrageenan using KOH = 0.04, NaOH = 0.02, and Ca(OH)2 = 0.02. The brittle fracture index (BFI) of the carrageenan was KOH = 0.67, NaOH = 0.26, and Ca(OH)2 = 0.04. The order of carrageenan solubility in water was NaOH > KOH > Ca(OH)2. These data can be used as the basis for the development of carrageenan for excipients in solid dosage forms. [ABSTRACT FROM AUTHOR]

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The giant honey bee Apis dorsata has a vast distribution in Asia, including in the Indonesian archipelagos, whereas A. d. binghami is endemic to Sulawesi Island. This research aimed to analyze the variations of landmarks in wing venation of A. dorsata from Sumatra, Belitung, Java, Sumbawa, Moluccas islands, and A. d. binghami in Sulawesi, based on geometric morphometric analysis. Nineteen landmarks from 200 wing venations were analyzed using Thin Plate Spline software. Our study found landmarks 16 and 17, known as Cubital Index in traditional morphometrics, contributed to the wing shape of A. dorsata and A. d. binghami Among all samples, these two landmarks show high displacement in the wing shape of A. d. binghami in Sulawesi and A. dorsata in the Moluccas. On the contrary, we found that the Sumatra, Belitung, and Java Apis dorsata revealed low displacement in the deformation grid; resulting in their shapes being more similar to the reference landmark. The variations of wing shape separate A. d. binghami from Sulawesi and Sumbawa in the Principle Component Analysis and agreement with the Neighbor-joining tree. Therefore, the geometric morphometric based on landmarks of wing venation is a powerful tool to discriminate the subspecies level of A. dorsata. [ABSTRACT FROM AUTHOR]

Epiphytic diatoms are phytoplankton groups commonly attached to substrates such as macroalgae. This study analyzes the community structure and diversity of epiphyte diatoms attached to Eucheuma denticulatum cultivated using the horizontal floating cage method. Six thalli of E. denticulatum propagules were taken randomly from each station. The samples were analyzed and identified in the laboratory. The research results clarified that epiphytic diatom composition consisted of 3 classes, two orders, 38 genera, and 79 species. The three classes that have been found include class Coscinodiscophyceae (10 genera) with percentages ranging between 8-34%, class Fragillaryophyceae (12 genera) with percentages ranging between 34-46%, and class Bacillariophyceae (16 genera) with percentages ranging between 26-46%. The uniformity index was 0.8287- 0.9286, which is considered relatively high. The dominance species index was 0.0644-0.2055, categorized as low. Fluctuations in water's physical and chemical factors have no significant effect on the growth of diatom epiphytes in the thallus of E. denticulatum. [ABSTRACT FROM AUTHOR]

The term 'eucheumatoids' designates a group of genera in the family Solieriaceae that are the source of some of the most valuable algal products in cultivation. While economically important in the tropics, much of its taxonomy is yet to be fully resolved. The eucheumatoid species Mimica arnoldii is a Batesian mimic of corals that was recently transferred to its own genus from Eucheuma based primarily on peculiarities of habit and a lack of medullary rhizoids, in contrast to the generitype Eucheuma denticulatum that has the latter. We studied the diversity of Mimica arnoldii from samples collected in the Philippines to determine their genetic variation, relationships to other eucheumatoids, and whether its two distinct morphological expressions, which have been named as varieties, are genetically different. We produced a phylogeny using a three-gene concatenated dataset, and used the variable mitochondrial cox2-3 spacer to determine intraspecific variation and the degree of correlation between sequence-variation and varietal status. Our results showed that Mimica is a distinct genus, and that intra-specific molecular data did not correspond to the morphology-based varieties, although it did correlate with geographical distribution. Our results also indicate that Kappaphycus, as presently circumscribed, contains species with (Kappahycus alvarezii, K. striatus and K. malesianus) and without (Kapppahycus cottonii) internal medullary hyphal core, and that K. cottonii is sister to the remaining Kappaphycus species. We thus propose Kappaphycopsis gen. nov. for K. cottonii for the species of Kappaphycus without internal medullary rhizoids (anaxiferous). [ABSTRACT FROM AUTHOR]

The use of organophosphate pesticides in developing countries is already widespread and can contaminate animal feed or human food ingredients which has an impact on liver damage and other organs. The use of seaweed containing polyphenols as a hepatoprotector for organophosphate poisoning has not been widely used by the public. The purpose of this study was to determine the potential of seaweed extract as a hepatoprotector in organophosphate-induced rabbits as seen from serum glutamate oxaloacetate transaminase (SGOT) and serum glutamate pyruvate transaminase (SGPT) levels. This study used a complete randomized design with 20 male rabbits as experimental animals which were divided into 4 treatments with 5 repetitions, namely: P0 was the control group which was only given distilled water, P1 was the group given seaweed extract at a dose of 200 mg/Kg BW, P2 is the group given seaweed extract at a dose of 400 mg/KgBB and P3 is the positive control group which is not given seaweed extract and distilled water. On the 15th day the P1, P2, and P3 groups were given profenofos pesticide at a dose of 50 mg/kg BW. The results showed a very significant difference (p-value = 0.02, a = 0.05) in SGOT levels between the P0 control group (135.4 ± 67.00 U/L) and the P1 treatment group (41.8 ± 17.45 U/L), P2 (25.8 ± 8.75 U/L), and the positive control group P3 (70 ± 29.04). The results of the study also found that there was no significant difference in SGPT levels in the P0 control group and the P1, P2, and P3 control groups. Giving seaweed extract with different doses provides a hepatoprotector effect by reducing the release of SGOT into the blood. [ABSTRACT FROM AUTHOR]

Sand sea cucumber (Holothuria scabra) is a high economic value as a food source. Sea cucumbers contain beneficial bioactive compounds for health. This study determined the sea cucumber growth cultured in an integrated multitrophic aquaculture (IMTA) with different water exchange systems in Lifuleo waters from October to December, 2020. This study was performed in an experimental method with three different exchange system treatments and three replications, namely once every 2 days (tank A), every day (tank B), and water circulation every day (tank C). Briefly, sand sea cucumbers with 116.72 ± 117.91 g body weight and 11.06 ± 11.83 cm length were maintained for 45 days with different water exchange systems and fed with Eucheuma cottonii. The results showed that the best water exchange systems to increase sand sea cucumber production was tank A with 100% survival rate, 1.84 ± 0.06%/day specific growth rate, and 1714.96 ± 34.13 μm length growth rate. The water quality parameters were also optimal during the sand sea cucumber with the integrated system. [ABSTRACT FROM AUTHOR]

Red seaweed species Eucheuma cottonii was thought to have potential as an anesthetic agent because it is shown to contain compounds with bioactivity as antimicrobial, antifungal, and also anticancer. There have been no studies regarding the active ingredients of anesthetized. The objective of the study was to examine the potential of E. cottonii extract as a candidate for fish anesthetic based on toxicity, phytochemistry, and active compounds contained in the extract. The stages of research include extraction, toxicity test extracts (BSLT), phytochemical test, quantitative test compound phytochemical results, and the identification of active compounds with LC-MS. Test results showed that E. cottonii extract contains a total of phenols of 4.60 ± 0.06 mg/GAE g which is one presentation of the active ingredient in the extract. The extract had bioactivity with LC50 of 221.71 ± 5.74 µg/mL. E. cottonii extract contained flavonoids compounds and saponins with a consecutive number of 24.48% and 0.22%. The results of identifying active compounds were found in several compounds that had activity asantidepressants or sedatives. E. cottonii extract can be used as a candidate for a fish anesthetic agent. [ABSTRACT FROM AUTHOR]

Studies have shown that cultivars of the carrageenophytes Kappaphycus and Eucheuma are clones of a limited number of strains originally domesticated from wild populations. For the development and selection of new cultivars, it is important that a comprehensive record of available variants exists. This study was conducted to provide up-to-date analysis and compilation of the current state of cultivars as the last list of cultivars was compiled nearly a decade ago. The present study analyzed the cox2–3 spacer and cox1 (1356 bp) genetic diversity of cultivars collected from 2019 to 2020 from the east coast of Sabah where the seaweed farms are concentrated. These data were compared with cultivars reported from 2010 to 2012 to assess changes, if any, to the gene pool of farmed eucheumatoid in Malaysia. Kappaphycus alvarezii, K. striatus, and K. malesianus are currently cultivated while Eucheuma denticulatum is no longer an important cultivar compared to a decade ago, probably due to its lower price. Analysis of the cox2–3 spacer revealed a new haplotype, LBT10, and, by including published GenBank data, a further four previously unnamed haplotypes were recognized from Sabah. This study confirms that there is a limited gene pool within cultivars in Malaysia and suggests the need for new or genetically diverse cultivars which can adapt to a changing environment, to ensure a more sustainable carrageenan industry. [ABSTRACT FROM AUTHOR]

Ulva lactuca is one of the macro-epiphytes of farmed seaweeds Kappaphycus spp. and Eucheuma denticulatum in Tawi-Tawi, southern Philippines, especially during the summer season, which affects the growth and health of farmed seaweeds. In this study, the abundance of culturable heterotrophic marine bacteria from U. lactuca associated with farmed seaweeds Kappaphycus spp. and E. denticulatum was investigated in the seaweed farms of Tongsibalo, Sibutu, Tawi-Tawi, southern Philippines, using serial dilution procedure. Results revealed that the average bacterial counts obtained from U. lactuca associated with Kappaphycus alvarezii, K. striatus, and E. denticulatum were 2.48 x 1010 CFU g-1, 1.14 x 1012 CFU g-1, and 1.32 x 1011 CFU g-1, respectively. In addition, agardigesting bacteria were observed from U. lactuca samples associated with K. alvarezii and K. striatus manifested by the depression and liquefaction of the marine agar after 2-3 days which were suspected as pathogenic bacteria causing ice-ice disease. Therefore, U. lactuca may serve as a vector for these potential pathogens to farmed seaweeds. [ABSTRACT FROM AUTHOR]

The impact of cottonii (COT, Kappaphycus alvarezii) and spinosum (SPI, Eucheuma denticulatum) flour (1–10% w/w) on rheological properties of wheat (WHE) and quality of bread was investigated. Wheat-COT and WHE-SPI had higher water absorption capacities, dough development times, dough stabilities and farinograph quality numbers than WHE dough. Extensograms of composite dough were largely similar to those of WHE at the same incubation times. Dough energy decreased whereas elasticity ratio (ratio of maximum resistance to extensibility) increased when incubation time was increased from 45 to 135 min. Wheat-COT and WHE-SPI had lower pasting temperatures but higher peak, final, breakdown and setback viscosities than WHE flour. Specific volume of bread containing COT (5% w/w) or SPI (7.5% w/w) was not different (p > 0.05) from that of WHE bread. Crumb texture properties of these composite breads were also largely similar to those of WHE bread. The physical properties of WHE dough and bread were influenced by gluten, whereas those of WHE-COT and WHE-SPI were influenced by gluten in addition to κ-carrageenan in COT and ι-carrageenan in SPI. Protein, ash and dietary fibre contents increased (p < 0.05) whereas carbohydrate content of bread decreased (p < 0.05) when WHE was replaced with COT or SPI (5% w/w). [ABSTRACT FROM AUTHOR]

Kappaphycus spp. and Eucheuma spp. are two economically significant seaweed species cultivated globally due to their carrageenan content with numerous commercial applications. They are mainly cultivated in the Philippines, Indonesia, Malaysia, and Tanzania. The culture of these seaweeds also provides income sources for many coastal dwellers. In 2018, the total global production from these seaweeds was about 11 million tonnes. One of the primary problems that affect seaweed production is the incidence of ice-ice disease. In this article, we reviewed the reported scientific journals on the ice-ice disease of two commercially cultured seaweed species (Kappaphycus spp. and Eucheuma spp.), focusing mainly on causes, occurrence, and control measures. The ice-ice disease is caused by both abiotic and biotic factors manifested by the presence of white and soft parts in the infected seaweeds. The occurrence of this disease varies from species, places, and seasons. Control measures may include proper farm management, polyculture with other seaweeds, pre-soaking with antibacterial substances and nutrient enrichment before out-planting, and possibly using genetic engineering. [ABSTRACT FROM AUTHOR]

The impact of Eucheuma on water loss and status in sponge cakes was measured and analyzed in this study. Eucheuma was used to replace 0%, 10%, and 20% of wheat flour to make sponge cakes, coded as the control, EP10, and EP20, respectively. The initial water content of batters showed no significant differences (around 57.0%, dry basis), whereas the final EP10 and EP20 products had higher water content. Three stages were found during baking in control sample and these three stages were fitted by linear, linear, and exponential models with root mean squared error (RMSE) of 0.016, 0.018, and 0.133, respectively. Eucheuma addition decreased the water loss rate and changed the water loss stages, which were fitted by linear, linear, and linear models in EP20 sample (RMSE = 0.027, 0.047, and 0.108, respectively). The crust formation and crumb structure analysis showed that the formation of cracks and the disappearance of pore structures hindered the water evaporation. The low‐field proton nuclear magnetic resonance and magnetic resonance imaging results showed that the water status in the final EP20 products was not as tightly as that in the control samples. A proposed schematic diagram was developed based on the qualitative analysis of the transfer mechanisms to explain the total effect of Eucheuma on the water loss rate and status. These results aid our understanding of the water loss process of sponge cakes and promote the potential application of Eucheuma in bakery products. Practical Application: Eucheuma as a flour replacement can improve the contents of dietary fiber and minerals like potassium of sponge cake. The impact of Eucheuma on water loss and status in sponge cake was measured and analyzed in this study. The results can promote the potential application of Eucheuma in bakery products and predict the quality attributes of baking products. [ABSTRACT FROM AUTHOR]

Farming of eucheumatoid seaweeds is a widespread, promising activity and an important livelihood option in many tropical coastal areas as for example in East Africa, Western Indian Ocean (WIO). Compared to other types of aquaculture, seaweed farming has generally low impact on the environment. Nonetheless, there are potential direct or indirect negative effects of seaweed farming, such as introduction of alien species and changes in local environmental conditions. Although farming has been practiced in this region during several decades, the knowledge concerning the actual environmental impacts from faming non-native eucheumatoid haplotypes and consequently how to manage farming activities to mitigate those is highly limited. In this review, we provide a summary of the current scientific knowledge of potential direct and indirect negative environmental effects linked to eucheumatoid seaweed farming such as alterations of benthic macrophyte habitats and loss of native biodiversity. Furthermore, we highlight knowledge gaps that are of importance to address in the near future, e.g., large-scale ecosystem effects and farms as potential vectors of pathogens. We also provide a number of feasible management recommendations to be implemented for a continued development of environmentally sustainable seaweed farming practices in the WIO region, which includes spatial planning of farms to avoid sensitive areas and farming of native haplotypes of eucheumatoids instead of introduced specimens. [ABSTRACT FROM AUTHOR]

Kappaphycus alvarezii was introduced for mariculture purposes on the coast of São Paulo, southeast of Brazil, in 1995, and since then an experimental pilot cultivation has been maintained. Since it is an exotic species, the dispersion of thallus fragments, presence of reproductive structures and recruitment from spores were monitored bimonthly from November 2016 to January 2018. Fragment dispersion was analyzed on nine selected monitoring sites around the cultivation raft through visual observation and photographic records. To verify the presence of reproductive structures 40 individuals were collected randomly from the cultivation raft and analyzed under a light microscope and stereomicroscope. Reproductive structure recruitment was also evaluated using artificial substrata. The results showed that even 25 years after the introduction of K. alvarezii on the coast of São Paulo, the invasive behavior of this exotic species had not been recorded. There was no evidence of vegetative dispersion and/or establishment in the Ubatuba Bay. Reproductive structures were also not found during the monitoring period. However, we highlight the importance of permanent and systematic environmental monitoring to prevent any impact and to ensure a sustainable aquaculture. These results will contribute to the development of the cultivation of the non-native K. alvarezii in Brazil and to improving public policies of coastal management. [ABSTRACT FROM AUTHOR]

Indonesia is the world largest producer of the red seaweeds Kappaphycus and Eucheuma; however, this country is facing significant challenges such as disease outbreaks, epiphyte infestations and a loss in seedling quality. Biosecurity practices have been widely adopted in other aquaculture sectors and when enforced can help to limit the introduction and spread of diseases and pests. To assess current capacity for biosecurity in seaweed aquaculture in Indonesia, a systematic analysis of policy frameworks including legislation, regulatory tools, and national standards was conducted. Biosecurity themes and risks were used to evaluate current national biosecurity content. The results identified major challenges faced by the industry in order to implement biosecurity policies in practice. Barriers to implementation included unspecific reference to the seaweed aquaculture sector, limited variety of approaches to biosecurity, limited use of up-to-date scientific evidence, insufficient guidance for the use of precaution and insufficient inclusion of specific biosecurity hazards. In general, although national regulations are currently under revision, current policies indicate a lack of clarity where biosecurity is included. Six recommendations are suggested to incorporate proactive biosecurity actions into current frameworks, with the aim of improving the health and sustainability of the seaweed aquaculture sector in Indonesia. [ABSTRACT FROM AUTHOR]

A detailed understanding of physiological and reproductive processes in seaweeds has repeatedly proven to be an essential pre-requisite in the successful development of a sustainable industry. The prime example of this was the classical discovery of the "conchocelis"-phase of Pyropia (Porphyra) by Kathleen Mary Drew-Baker in 1949. Such elegant research proved to be pivotal to the development of a globally important "nori" industry which transitioned from the simple provision of the enhanced surface area of the substrata for spore settlement to the sophisticated, mechanized and computerized operations in modern hatcheries supplied by seedling banks of selected species and their cultivars. All of the pre-requisite knowledge was acquired through intensive applied research. However, not all solutions need to be high-tech; problems caused by epiphytes and contaminants have been achieved by exposing Pyropia nets periodically and was found to be effective. This protocol was achieved based on fundamental observations by farmers which were then complemented and refined by laboratory trials. Techniques must be adapted for site-specific differences, as abiotic factors such as water current and movement, surface seawater temperature, light regime and photoperiod, nutrients dispersion and water quality are interrelated, either positively or negatively, influencing seaweed productivity and the end-use of the biomass. Unfortunately, positive techniques that have been shown in vitro/silica can prove to be impractical once attempted at large-scale cultivation and/or the return on investment is not justified by the commercial value of the resultant seaweed biomass. This chapter presents a summary of how the judicious application of knowledge based on the eco-physiological processes of common seaweed species from tropical and cold-waters can assist the future development and scale-up of the global seaweed industry. [ABSTRACT FROM AUTHOR]

Eucheumatopsis isiformis Núñez-Resendiz, Dreckmann & Sentíes is a red alga with great economic potential due to its iota-carrageenan content that could serve as a substitute for traditional carrageenan sources (Freile-Pelegrín and Robledo, J Appl Phycol 20:537–541, 2008) such as the red alga Kappaphycus alvarezii (Loureiro et al., New Phytol 206:489–492, 2015), if it can be reliably and sustainably cultivated in open water. Due to prevailing and changing climatic conditions, it is necessary to retain germplasm and to cultivate this alga in tank systems. To develop the necessary, large volumes of seed stock required for stocking open water cultivation farms, three brown seaweed-derived biostimulants were tested. One of these was manufactured from the kelp Ecklonia maxima, the other two were manufactured from the intertidal fucoid Ascophyllum nodosum. Apical segments of E. isiformis were treated either by dipping or by continuous exposure to the biostimulants, at different concentrations. Growth was assessed every seven days by measuring the maximum length of each segment, number of lateral shoots produced by each shoot, fresh weight, and the maximum diameter. The constant exposure treatment produced a greater number of shoots per propagule with no significant effects driven by any of the biostimulants. Increasing or decreasing the concentration of the biostimulants to improve the performance of the dipping protocol was not effective, as compared with a constant exposure protocol. This study supports the increasing number of research articles related to the positive benefits of using macroalgal-derived extracts as biostimulants to support seaweed cultivation. [ABSTRACT FROM AUTHOR]

There is a continuous decrease in seaweed production as reflected in the annual seaweed production of the Province of Palawan which were attributed to the occurrence of diseases and pests in the seaweed farms. To monitor the number of diseases and pest present in seaweed farms in Palawan, a total of 13 selected municipalities in the province of Palawan that engage in seaweeds farming were monitored from any presence of diseases and pest from 2003 to 2018. Based on the result, a total of six diseases and one problem were identified to be present in the seaweed farms in the selected municipalities in Palawan. The ice-ice disease had highest frequency of occurrence followed by the epiphytes, tip discoloration, sudden whitening of the planted seaweeds, sedimentation, pitting and grazing respectively. Ice-ice disease caused thallus breakage results in the decrease of volume to be harvested by the farmers coupled with the slow growth rate of the plant thus regularly forces seaweed farmers to stop planting for months. Several mitigation strategies were already applied in the seaweed farms by the affected municipalities in Palawan but still, some diseases and pests arise from time to time. [ABSTRACT FROM AUTHOR]

To confirm the role of high-pressure processing in enhancing the quality of Eucheuma spinosum chicken breast batters, low-field nuclear magnetic resonance, scanning electron microscopy and Raman spectroscopy were used to explore the effect of E. spinosum and high-pressure processing on water migration, protein conformation, and microstructure in chicken breast batters. The water-holding capacity, surface hydrophobicity, and reactive sulfhydryl group content significantly increased as the pressure increased (0.1 to 300 MPa), while the peak ratio of non-flowable water (T 22) decreased (P > 0.05). The secondary structure composition changed significantly, and the β -sheet, β -turn, and random coil content significantly increased (P < 0.05) as the α -helix content decreased. The –OH stretching vibration (3,100 to 3,500 cm−1) was shifted to higher wavenumbers, and the number of hydrogen bonds in each water molecule increased. The scanning electron microscopy images reveal that proper pressure produced a dense network structure with small cavities. Moreover, these characteristics were further enhanced when E. spinosum was added from 0 to 0.4%. Overall, this paper could provide crucial theoretical support for the application of high-pressure processing of low-salt seaweed chicken breast. [ABSTRACT FROM AUTHOR]

Abstract Response Surface Methodology (RSM) based on Central Composite Design (CCD) was employed to optimize the conditions of enzymatic hydrolysis and fermentation of the seaweed Eucheuma cottonii. The significant influence of cellulose loading, enzyme loading and incubation time in enzymatic hydrolysis that has been screened by Plackett-Burman Design (PBD) was optimized using CCD. The optimum glucose concentration of 24.24 g/L (81% glucose yield) was obtained at 3% (v/v) of cellulose loading, 4% (v/v) of enzyme loading and 54 h incubation time. Subsequently, PBD analysis showed the significant effects of inoculum concentration, pH, temperature and time on fermentation process. Further optimization study by CCD revealed that 12% (v/v) of inoculum concentration, pH 5.2, 32 °C and 72 h of fermentation time enhanced the bioethanol production up to 9.77 g/L with the yield of 0.40 g/g and 78% conversion efficiency. Thus, the RSM based optimization of bioethanol from Eucheuma cottonii showed satisfactory results in this research. In short, it can be concluded that this optimization approach will serve as a good foundation for the realization of a consistent bioethanol production in the future. Highlights • Eucheuma cottonii seaweed was employed as the main feedstock for bioethanol production. • Enzymatic hydrolysis and fermentation were the main conversion technologies utilized. • Response Surface Methodology was used to optimize the enzymatic hydrolysis and fermentation for bioethanol production. [ABSTRACT FROM AUTHOR]

Invasive macroalgae Eucheuma sp. and Kappaphycus spp. (E/K) became a dominant benthic feature in Kāne'ohe Bay throughout the past four decades - occurring on up to 74 ha of reef area and growing up to three meters thick, which prompted intensive management action. In 2013, E/K cover began decreasing at managed and unmanaged sites. This study examined the extent and timing of the E/K decline and evaluated environmental and ecological drivers beyond management contributing to the decline. E/K continued to recede into 2017 and remains sparse in Kāne'ohe Bay today. Increasing over the sampling period, herbivore biomass was negatively correlated with E/K cover, and other significant, non-linear relationships emerged between E/K cover and coral cover, sea surface temperature, wind, and rainfall. This study uncovers several possible mechanisms explaining a boom and bust in E/K abundance, emphasizes the importance of herbivory, and highlights the resilience of coral reefs in Kāne'ohe Bay. • Invasive macroalgae (E/K) began declining in 2013 across Kāne'ohe Bay patch reefs. • Decline of E/K occurred at both managed and unmanaged sites around the same time. • Herbivore biomass was significantly negatively correlated with E/K cover. • E/K cover was moderated by complex suite of environmental drivers. [ABSTRACT FROM AUTHOR]

Eucheumatoid seaweed farming (ESF) is an important enterprise that provides livelihood opportunities for tropical coastal communities. In this work, we surveyed the current practices of ESF in Tawi-Tawi and Sulu, southern Philippines, where major commercial ESF activities in the country are currently practiced. Seaweed farmers (N = 143) were interviewed using a structured questionnaire containing relevant information on the current farming practices. Results revealed that ESF is one of the primary livelihood sources for coastal inhabitants in the southern Philippines. Most farmers were male, 21–50 years old, and practiced farming for 6–10 years. Farmers mostly owned a farm with an area of 25–400 m2, mainly filled with the rhodophyte elkhorn sea mosses, either Kappaphycus alvarezii or K. striatus. Vegetative cuttings, the major seedling source, were tied using plastic straw into a 6–10 m rope line with a distance interval of 10–20 cm. Inorganic nutrient enrichment is practiced to increase growth and lessen ice-ice disease occurrence. The modified fixed-off bottom (stakes with floaters) is the most predominant farming method. Farms were visited 2–3 times a week for maintenance. Farming is year-round, with peak seasons between August and November. Harvesting is typically done after 21–30 days. Seaweeds are usually dried using the hanging method, which takes 4–6 days. Dried Kappaphycu s fronds command higher prices (90–140 PHP/kg) compared to Eucheuma denticulatum (10–50 PHP/kg). Few farmers received government support; therefore, farmers reported many problems affecting their production. This study provides an update on the current ESF practices in the southern Philippines, which have not been well-documented for almost two decades. • Eucheumatoid seaweed farming provides livelihood opportunities for a large sector of southern Philippines residents. • Modified fixed-off bottom method is the most prominent method for eucheumatoid seaweed farming in the southern Philippines. • Kappaphycus alvarezii and K. striatus are the most important species farmed in the southern Philippines. [ABSTRACT FROM AUTHOR]

Invasive macroalgae pose a serious threat to coral reef biodiversity by monopolizing reef habitats, competing with native species, and directly overgrowing, and smothering reef corals. Several invasive macroalgae (Eucheuma clade E, Kappaphycus clade A and B, Gracilaria salicornia, and Acanthophora spicifera) are established within Kāne‘ohe Bay (O‘ahu, Hawai‘i, USA), and reducing invasive macroalgae cover is a coral reef conservation and management priority. Invasive macroalgae control techniques, however, are limited and few successful large-scale applications exist. Therefore, a two-tiered invasive macroalgae control approach was designed, where first, divers manually remove invasive macroalgae (Eucheuma and Kappaphycus) aided by an underwater vacuum system (“The Super Sucker”). Second, hatchery-raised juvenile sea urchins (Tripneustes gratilla), were outplanted to graze and control invasive macroalgae regrowth. To test the effectiveness of this approach in a natural reef ecosystem, four discrete patch reefs with high invasive macroalgae cover (15–26%) were selected, and macroalgae removal plus urchin biocontrol (treatment reefs, n = 2), or no treatment (control reefs, n = 2), was applied at the patch reef-scale. In applying the invasive macroalgae treatment, the control effort manually removed ∼19,000 kg of invasive macroalgae and ∼99,000 juvenile sea urchins were outplanted across to two patch reefs, totaling ∼24,000 m2 of reef area. Changes in benthic cover were monitored over 2 years (five sampling periods) before-and-after the treatment was applied. Over the study period, removal and biocontrol reduced invasive macroalgae cover by 85% at treatment reefs. Our results show manual removal in combination with hatchery raised urchin biocontrol to be an effective management approach in controlling invasive macroalgae at reef-wide spatial scales and temporal scales of months to years.

Objective: To explore the potential of local agar of genus Gracilaria, Eucheuma, Gelidium and local brands as an alternative for imported agarose for DNA electrophoresis, and to examine their ability related to separation and migration of DNA fragments in DNA electrophoresis. Methods: Their performance at various concentrations were compared via an experimental study with a specific brand of imported commercial agarose used in molecular biology research. The measured variables were separation and migration during electrophoresis of a DNA fragment. Results: The local agar genus Gracilaria gigas, Gelidium, brand “B” and brand “S” could separate DNA fragments at a concentration between 1% and 2%, with an optimum concentration of 2% w/v, as good as a specific brand of imported commercial agarose. Conclusions: Their performance were very close to that of commercial agarose and can still be improved by further agar purification as well as by pH and sulfur control.

On the basis of COI-5P, cox2-3 spacer, RuBisCo spacer, and rbcL sequences, Eucheuma was resolved as a paraphyletic genus in the Solieriaceae. Specimens of E. isiforme from the Yucatan Peninsula and Florida form an independent lineage in the family that was also different from E. denticulatum, the generitype. To accommodate this species, we described Eucheumatopsis as a new genus that differs from Eucheuma both molecularly and geographically. Because the four molecular markers used and morphological characters did not support the independence of Eucheuma isiforme var. denudatum from E. isiforme var. isiforme, we have proposed to no longer recognize var. denudatum as a separate variety. [ABSTRACT FROM AUTHOR]

Carrageenans are important hydrocolloids extracted from red seaweeds (Rhodophyceae) of genus Eucheuma, Iridiae, Gigartina, and Chondrus. Carrageenan extraction technologies currently applied in modern industries are based on conventional heating using double-jacketed tanks supplied with steam as heating medium. This technology is inefficient in energy use and posesa complicated processing setup since it requires a dedicated steam generator and steam delivery system. The objective of this study was to develop an ohmic-based novel technology for seaweed processing. The system developed and used in this study consisted of three ohmic heating chambers (7.5 liter each) working in parallel in static mode. The system was tested for iota carrageenan extraction from Eucheuma denticulatum (known commercially as Eucheuma spinosum) using 0.3M KOH solution as extracting medium with seaweed to solution ratio of 1:35 (w/v).The tests were conducted at several temperatures and extraction durations to gain broad insights on the effectiveness of this novel technology. The test results indicated that this technology can efficiently extract carrageenan from E. spinosum with yields in the range of 41-61% (dry weight basis) and viscosity and gel strength in the range of 269-274 cP and 50.87-55.27 g/cm2 respectively. These results suggest that ohmic-based seaweed processing technology is a viable alternative to conventional technologies currently applied in industries. [ABSTRACT FROM AUTHOR]

Litopenaeus vannamei is one of the most well-known fishery products and has high market value. In contrast, production of vannamei shrimp is facing threats from several diseases caused by bacteria, virus, and even parasites that attack the shrimp immune system. The purpose of this study is to identify the immunomodulatory effect of Eucheuma serra extract to enhance haemocyte cells production in Litopenaeus vannamei as the non-specific internal immune substance. The research method used was a complete randomised design with 5 concentrations of injected Eucheuma serra extract treatments and one placebo as control. Eucheuma serra extract administered on shrimp abdomen and the haemocyte cell samples collected from shrimp on day 0 and day 6. Treatment using 8 ppm injected Eucheuma serra extract showed the highest haemocyte cell amount increase about 15.90 million cells/ml in 6 days after injection. Statistical calculation using ANOVA test showed a significant difference in the amount of haemocyte cell at before and after treatment. [ABSTRACT FROM AUTHOR]

Invasive macroalgae pose a serious threat to coral reef biodiversity by monopolizing reef habitats, competing with native species, and directly overgrowing, and smothering reef corals. Several invasive macroalgae (Eucheuma clade E, Kappaphycus clade A and B, Gracilaria salicornia, and Acanthophora spicifera) are established within Kaneohe Bay (O'ahu, Hawai'i, USA), and reducing invasive macroalgae cover is a coral reef conservation and management priority. Invasive macroalgae control techniques, however, are limited and few successful large-scale applications exist. Therefore, a two-tiered invasive macroalgae control approach was designed, where first, divers manually remove invasive macroalgae (Eucheuma and Kappaphycus) aided by an underwater vacuum system ("The Super Sucker"). Second, hatchery-raised juvenile sea urchins (Tripneustes gratilla), were outplanted to graze and control invasive macroalgae regrowth. To test the effectiveness of this approach in a natural reef ecosystem, four discrete patch reefs with high invasive macroalgae cover (15-26%) were selected, and macroalgae removal plus urchin biocontrol (treatment reefs, n=2), or no treatment (control reefs, n = 2), was applied at the patch reef-scale. In applying the invasive macroalgae treatment, the control effort manually removed ~19,000 kg of invasive macroalgae and ~99,000 juvenile sea urchins were outplanted across to two patch reefs, totaling~24,000m² of reef area. Changes in benthic cover were monitored over 2 years (five sampling periods) before-and-after the treatment was applied. Over the study period, removal and biocontrol reduced invasive macroalgae cover by 85% at treatment reefs. Our results show manual removal in combination with hatchery raised urchin biocontrol to be an effective management approach in controlling invasive macroalgae at reef-wide spatial scales and temporal scales of months to years. [ABSTRACT FROM AUTHOR]