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  • Thirty species of marine algae collected from different localities of Mandapam coast (Gulf of Mannar) were analyse!! for their photosynthetic pigments suct. as chlorophyll and carotenoids. The lowest value. of chlorophyll as well as carotenoids content were found in Rhodophyceae. The grouping and separation of algae based on coloration has been practiced for over 100 years (Harvey, 1841). Pigments such as chlorophyll and carotenoids play important roles in photosynthesis. Several studies have been conducted in the algal pigment by Ramus el al. (1976); Brody el al. (1959); Jones el at. (1965) and Waaland el al. (1974). As there is no detailed work in this line on India.l seaweeds, the present study.of thirty species of marine algae belonging to Chlorophyta, Phaeophyta and Rhodophyta from Mandapam coast has been carried out.

    Author(s): Jayasankar, Reeta, Ramalingam, J R
  • Biofuels Co-products Workshop Hosted by the Aquatic Feeds & Nutrition Dept. Oceanic Institute.

    Author(s): F.C. Thomas Allnutt
  • Macroalgae, or seaweeds, are multicellular – usually macroscopic – plant-like organisms that generally live attached to rock or other hard substrata in coastal areas. There are about 10,000 species of algae, of which 6,500 are red algae (also named Rhodophyta), 2,000 are brown algae (Phaeophyceae), and 1500 are green algae (Chlorophyta and Charophytes). These three groups have very distinct evolutionary histories and display specific ultrastructural and biochemical features (e.g. pigments). 

    Seaweeds are increasingly employed as feedstock around the world, with an annual production of 30Mt for a ~ €8B value. Seaweeds are thus a promising bioresource for the future and demands for high-value seaweed-derived compounds (cosmetics, food) are on the rise in Europe. However, the production of Europe lags behind that of Asian countries despite its large exclusive economic zone, its high seaweed biodiversity and its international leadership in fundamental research on macroalgae.

    Drawing on our long-term experience in plant production and domestication in general, as well as on current knowledge of European and worldwide marine ecology, climate and trade, we explore the reasons for this lag, and offer recommendations for improving seaweed cultivation and harvest.

    Based on a detailed analysis of current seaweed aquaculture practices, regulations, health benefits and consumer demands, these guidelines aim to foster sustainability and protection of the marine environment. These guidelines also include expert opinions and assessments from the academic, private and associative sectors, based mainly in Europe, but also on other continents. With this wide scope and using a field-based and scientific approach, we have aimed to produce a robust prospective reference document to support policy-makers and the elaboration of future European regulations.

    Author(s):
  • Rafting on floating seaweeds facilitates dispersal of associated organisms, but there is little information on how rafting affects the genetic structure of epiphytic seaweeds. Previous studies indicate a high presence of seaweeds from the genus Gelidium attached to floating bull kelp Durvillaea antarctica (Chamisso) Hariot. Herein, we analyzed the phylogeographic patterns of Gelidium lingulatum (Kützing 1868) and G. rex (Santelices and Abbott 1985), species that are partially co-distributed along the Chilean coast (28°S–42°S). A total of 319 individuals from G. lingulatum and 179 from G. rex (20 and 11 benthic localities, respectively) were characterized using a mitochondrial marker (COI) and, for a subset, using a chloroplastic marker (rbcL). Gelidium lingulatum had higher genetic diversity, but its genetic structure did not follow a clear geographic pattern, while G. rex had less genetic diversity with a shallow genetic structure and a phylogeographic break coinciding with the phylogeographic discontinuity described for this region (29°S–33°S). In G. lingulatum, no isolation-by-distance was observed, in contrast to G. rex. The phylogeographic pattern of G. lingulatum could be explained mainly by rafting dispersal as an epiphyte of D. antarctica, although other mechanisms cannot be completely ruled out (e.g., human-mediated dispersal). The contrasting pattern observed in G. rex could be attributed to other factors such as intertidal distribution (i.e., G. rex occurs in the lower zone compared to G. lingulatum) or differential efficiency of recruitment after long-distance dispersal. This study indicates that rafting dispersal, in conjunction with the intertidal distribution, can modulate the phylogeographic patterns of seaweeds.

    Author(s): Boris A. López, Florence Tellier, Juan C. Retamal‐Alarcón, Karla Pérez‐Araneda, Ariel O. Fierro, Erasmo C. Macaya, Fadia Tala, Martin Thiel
  • The physical aspects of ocean kelp farming were studied in the context of farms sited in nearshore coastal waters. Analyses and models were employed to investigate the physical oceanographic and ocean engineering problems underlying conceptual designs of nearshore kelp farms. The areas addressed include interactions between ocean coastal currents and kelp farms, distribution and transport of fertilizer in and around the farm, interactions between surface water waves and kelp farms, effects on adjacent shorelines of wave field modifications due to the farm, and wave forces on kelp plants.

    For the range of coastal conditions and farm configurations examined, it was found that the flow of ocean currents is significantly retarded within the farm and flows are deflected in a narrow band around the farm; substantial losses from the farm of applied fertilizer result from advection within the farm; water wave heights can be significantly reduced within the farm due to the kelp, and a shadow zone of reduced waves may extend significantly shoreward of the farm; the shadow zone may, under certain conditions, result in shoreline modification; and wave forces on the kelp have inertial components of the same order of magnitude as buoyancy forces.

    Author(s): J. D. Ditmars, D. P. Wang
  • The impact of air-drying at 25 ◦C, brining at 25%, and dry-salting (at 28% and 40%) on the quality and nutritional parameters of Ulva rigida were evaluated over six months of storage. Overall, the main changes occurred in physical aspects during storage time, with U. rigida intensifying its yellow/browning tones, which were more evident in salt-treated samples. The force necessary to fracture the seaweed also increased under all the preservative conditions in the first month. Conversely, the nutritional parameters of U. rigida remained stable during the 180 days of storage. All processed samples showed a high content of insoluble and soluble fibers, overall accounting for 55%–57% dw, and of proteins (17.5%–19.2% dw), together with significant amounts of Fe (86–92 mg/kg dw). The total fatty acids pool only accounted for 3.9%–4.3% dw, but it was rich in unsaturated fatty acids (44%–49% total fatty acids), namely palmitoleic (C16:1), oleic (C18:1), linoleic (C18:2), linolenic (C18:3), and stearidonic (18:4) acids, with an overall omega 6/omega 3 ratio below 0.6, a fact that highlights their potential health-promoting properties. 

    Author(s): Valentina F. Pinheiro, Catarina Marçal, Helena Abreu, José A. Lopes da Silva, Artur M. S. Silva, Susana M. Cardoso
  • Eulittoral seaweeds at different tidal elevations are exposed to various frequencies and durations ofemergence. Their physiological activities (e.g. nutrient uptake) may be affected by water loss duringemersion. We used threePorphyraspecies from different tidal elevations to test whether species at differentvertical elevations on the shore respond differently to the increasingly non-marine environment, in terms oftheir physiological activities including nutrient uptake, tissue carbon, nitrogen and phycoerythrin contents.Simulated tidal cycles produced water losses of 0%, 40 ± 10% and 90 ± 5% tissue water. Emersion was stressfulfor all species regardless of their habitat. It was more stressful to nitrate and phosphate uptake for thesublittoral speciesP. yezoensisthan eulittoral species,P. umbilicalisandP. leucosticta. Interestingly, tissue Nfor thalli that had been emerged and then re-submerged was significantly higher than those of continuouslysubmerged individuals. During exposure, tissue N contents of all species declined but recovered quickly (e.g.within 30 min) after re-submergence. This result suggests that emersion-induced N release may constitutean undescribed biogeochemical pathway linking marine, terrestrial, and atmospheric N reservoirs.

    Author(s): Yarish, Charles Jang K. Kim, George P. Kraemer
  • Poor physiological acclimatization to climate change has led to shifts in the distributional ranges of various species and to biodiversity loss. However, evidence also suggests the relevance of non-climatic physical factors, such as light, and biotic factors, which may act in interactive or additive way. We used a mechanistic approach to evaluate the ecophysiological responses of four seaweed species (three dominant intertidal fucoids, Fucus serratus, Ascophyllum nodosum, Bifurcaria bifurcata, and the invasive Sargassum muticum) to different conditions of grazing, light irradiance and ultraviolet (UV) radiation. We performed a large-scale mesocosm experiment with a total of 800 individual thalli of macroalgae. The factorial experimental design included major algal traits, photoacclimation, nutrient stoichiometry and chemical defence as response variables. Few significant effects of the factors acting alone or in combination were observed, suggesting a good capacity for acclimatization in all four species. The significant effects were generally additive and there were no potentially deleterious synergistic effects between factors. Fucus serratus, a species currently undergoing a drastic contraction of its southern distribution limit in Europe, was the most strongly affected species, showing overall lower photosynthetic efficiency than the other species. The growth rate of F. serratus decreased when UV radiation was filtered out, but only in the presence of grazers. Moreover, more individuals of this species tended to reach maturity in the absence of grazers, and the nitrogen content of tissues decreased under full-spectrum light. Only the phlorotannin content of tissues of B. bifurcata and of exudates of A. nodosum, both slow-growing species, were positively affected by respectively removal of UVB radiation and the presence of grazers. The findings for S. muticum, a well-established invasive seaweed across European coasts, suggested similar physiological response of this fast-growing species to different levels of grazing activity and light quality/intensity. As expected, this species grew faster than the other species. Bifurcaria bifurcata and A. nodosum only showed minor effects of light quality and grazing on phlorotannins content, which suggests good resistance of these two long-lived species to the experimental conditions. Mechanistic approaches that are designed to analyse interactive effects of physical and biotic factors provide an understanding of physiological responses of species and help to improve the confidence of predictive distribution models.

    Author(s): Brezo Martínez, Jesús S. Troncoso, Ángela Fernández, Francisco Arenas, Celia Olabarria
  • The methanol extract of Kappaphycus alvarezii was evaluated for antibacterial activity and against the human clinical isolated pathogens of Staphylococcus aureus, Bacillus cereus, Pseudomons aeroginosa, Escherichia coli, Proteus vulgaris and Bacillus subtilis. The phytochemical analysis showed the presence of alkaloids, saponin, phenols, terpenoids, coumarins, protein, carbohydrates, flavonoids, tannins and absence of steroids, glycosides and anthraquinone. Kappaphycus alvarezii possesses significant antibacterial activity and in future the methanol extract may pave the way for designing the new drugs for controlling bacterial diseases. 

    Author(s): Seetharaman S., Geetha S., Daisy A., Selva Muthu B.
  • Background: Marine algae are rich in some unique biologically active secondary metabolites having diverse pharmacological benefits. Of these, sterols comprise a group of functional lipid compounds that have attracted much attention to natural product scientists. Purpose: This review was aimed to update information on the health effects of algae-derived phytosterols and their molecular interactions in various aspects of human health and diseases and to address some future perspectives that may open up a new dimension of pharmacological potentials of algal sterols. Methods: A literature-based search was carried out to retrieve published research information on the potential health effects of algal phytosterols with their pharmacological mechanisms from accessible online databases, such as Pubmed, Google Scholar, Web of Science, and Scopus, using the key search terms of ‘marine algae sterol’ and ‘health potentials such as antioxidant or anti-inflammatory or anti-Alzheimer's or anti-obesity or cholesterol homeostasis or hepatoprotective, antiproliferative, etc.’ Results: Phytosterols of marine algae, particularly fucosterol, have been investigated for a plethora of health benefits, including anti-diabetes, anti-obesity, anti-Alzheimer's, antiaging, anticancer, and hepatoprotection, among many others, which are attributed to their antioxidant, anti-inflammatory, immunomodulatory and cholesterol-lowering properties, indicating their potentiality as therapeutic leads. These sterols interact with enzymes and various other proteins that are actively participating in different cellular pathways, including antioxidant defense system, apoptosis and cell survival, metabolism, and homeostasis. Conclusion: In this review, we briefly overview the chemistry, pharmacokinetics, and distribution of algal sterols, and provide critical insights into their potential health effects and the underlying pharmacological mechanisms, beyond the well-known cholesterol-lowering paradigm.

    Author(s): Md. Abdul Hannan, Abdullah Al Mamun Sohag, Raju Dash, Md. Nazmul Haque, Md. Mohibbullah, Diyah Fatimah Oktaviani, Md. Tahmeed Hossain, Ho Jin Choi, Il Soo Moon

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