In the past 15 years, scientific focus on the marine flora of the Northwestern Hawaiian Islands (NWHI) has intensified, resulting in a doubling of the total number of known species. In 1989, 205 species were recorded; as of January 2005, 353 species have been published for the NWHI. Over 5,100 specimens collected from Midway Atoll and other atolls, reefs, islands, and deep-water sites in the NWHI have shown a marine flora with geographic distribution patterns different from any known similar- sized area in the Pacific. Several new species of macroalgae have been described, including Dudresnaya babbittiana (Rhodophyta), Kallymenia thompsonii (Rhodophyta), Hydroclathrus tumulis (Phaeophyta), Padina moffittiana (Phaeophyta), and Codium hawaiiense (Chlorophyta). Since 1989, numerous macroalgal and two seagrass species have been documented as records of species new to the NWHI, including Kallymenia sessilis, Desmarestia ligulata, Nereia intricata, Sporochnus moorei, Caulerpa antoensis, C. cupressoides, C. elongata, C. microphysa, Halophila decipiens, and H. hawaiiana. Although the Hawaiian Archipelago is considered part of the Tropical Indo-West Pacific phytogeographic region, the NWHI's mixture of tropical species, cold-temperate species, species with disjunct distributions, and endemic species suggests alternative biogeographic patterns and dispersal routes.
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Deep subtidal marine plants from the Northwestern Hawaiian Islands: New perspectives on biogeography
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The effect of a range of chemical disinfectants at different concentration and exposure times was investigated on five macroalgal species and the marine gastropod Littorina spp. Palmaria palmata, Osmundea pinnatifida and Ulva lactuca are commercially valuable and are often cultivated in tanks for food or feed. Ectocarpus siliculosus and Ulva intestinalis are common epiphytes of P. palmata and O. pinnatifida cultures, whilst Littorina spp. are common herbivorous epibionts within U. lactuca culture tanks. These contaminants reduce the productivity and quality of the culture as a food. Differential tolerance to the treatments was seen between the algal species using pulse-amplitude modulation (PAM) chlorophyll a fluorescence, a few hours and a week following treatment. We identified treatments that selectively damaged the epiphyte but not the basiphyte species. Ectocarpus siliculosus had a significantly lower tolerance to 1 % sodium hypochlorite than P. palmata, and to 25 % methanol than O. pinnatifida, with a 1–5 min exposure appearing most suitable. Ulva intestinalis had a significantly lower tolerance than P. palmata and O. pinnatifida to many disinfectants: 0.1–1 % sodium hypochlorite for 10 min, 0.5 % potassium iodide for up to 10 min, and 0.25 % Kick-start (a commercial aquaculture disinfectant solution) for 1–5 min. No treatment was able to kill the gastropod snails without also damaging U. lactuca, although agitation in freshwater for an hr may cause them to detach from the basiphyte, with little to no photophysiological impact seen to U. lactuca. This experiment forms the basis for more extended commercial trials.
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Magnetic iron oxide nanoparticles (Fe3O4MNPs) are among the most useful metalnanoparticles for multiple applications across a broad spectrum in the biomedical field, includ-ing the diagnosis and treatment of cancer. In previous work, we synthesized and characterizedFe3O4MNPs using a simple, rapid, safe, efficient, one-step green method involving reduction offerric chloride solution using brown seaweed (Sargassum muticum) aqueous extract containinghydroxyl, carboxyl, and amino functional groups mainly relevant to polysaccharides, which actsas a potential stabilizer and metal reductant agent. The aim of this study was to evaluate the invitro cytotoxic activity and cellular effects of these Fe3O4MNPs. Their in vitro anticancer activitywas demonstrated in human cell lines for leukemia (Jurkat cells), breast cancer (MCF-7cells),cervical cancer (HeLa cells), and liver cancer (HepG2cells). The cancer cells were treated withdifferent concentrations of Fe3O4MNPs, and an MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyltetrazolium bromide) assay was used to test for cytotoxicity, resulting in an inhibitory concentra-tion 50 (IC50)value of 23.83±1.1μg/mL (HepG2), 18.75±2.1μg/mL (MCF-7), 12.5±1.7μg/mL(HeLa), and 6.4±2.3μg/mL (Jurkat) 72hours after treatment. Therefore, Jurkat cells were selectedfor further investigation. The representative dot plots from flow cytometric analysis of apoptosisshowed that the percentages of cells in early apoptosis and late apoptosis were increased. Cellcycle analysis showed a significant increase in accumulation of Fe3O4MNP-treated cells atsub-G1phase, confirming induction of apoptosis by Fe3O4MNPs. The Fe3O4MNPs also activatedcaspase-3and caspase-9in a time-response fashion. The nature of the biosynthesis and thera-peutic potential of Fe3O4MNPs could pave the way for further research on the green synthesisof therapeutic agents, particularly in nanomedicine, to assist in the treatment of cancer.
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Continuous exposure for 7–10 days to 60% of ambient levels (sea level at mid-day in December) of UV-A and UV-B radiation caused cytological damage to regenerating fragments of Griffithsia pacifica under laboratory conditions. There was high mortality of individual cells and entire fragments in UV treated filaments. Rhizoid initiation was slower and rhizoids grew more slowly following UV treatment. After 7 days, UV radiated thalli showed chloroplast and nuclear degeneration. In addition, filaments tended to disarticulate so that single or groups of apparently healthy cells were common in the medium. These data suggest that the subtidal habitat of G. pacifica is based in part on lack of tolerance to UV radiation, and that UV protection mechanisms are not inducible or insufficient to prevent the accumulation of damage in this species.
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Red algae (Rhodophyta) are a widespread group of uni- to multicellular aquatic photoautotrophic plants. They exhibit a broad range of morphologies, simple anatomy and display a wide array of life cycles. About 98% of the species are marine, 2% freshwater and a few rare terrestrial/sub-aerial representatives (Gurgel and Lopez 2007). Red algae are true plants in the phylogenetic sense since they share, with the green lineage (green alga e and higher plants), a single common ancestor (Adl et al. 2005). However, the phylum Rhodophyta is easily distinguished from other groups of eukaryotic algae due to a number of features listed below (Woelkerling 1990; Grossman et al. 1993; Gurgel and Lopez 2007):
(i) Total absence of centrioles and any fl agellate phase.
(ii) Presence of chlorophyll s a and d , and accessory pigments (light-harvest) called phycobilin s (phycoerythrin and phycocyanin).
(iii) Plastid s with unstacked thylakoid s, and no external endoplasmic reticulum.
(iv) Absence of parenchyma and presence of pit-connection s between cells (i.e. incomplete cytokinesis).
(v) Floridean starch as storage product.
Traditionally, red algae can be morphologically separated in three major groups: (1) a unicellular group with reproduction by binary cell division only, (2) a multicellular group where a carpogonial branch is absent or incipient (Bangiophyceae sensu lato) and (3) a multicellular group with well developed carpogonial branches (Florideophyceae).
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This symposium was held to assess the state-of-the-science and identify re- search needed to address the increasing risks posed by freshwater harmful algal blooms to human health and ecosystem sustainability. Information obtained through the symposium will help form the scientific basis for de- veloping and implementing strategies to reduce these risks.
All chapters in this book are based on platform sessions or draft workgroup reports that were presented at ISOC-HAB. All chapters were completed after the conclusion of ISOC-HAB. Each chapter was critically reviewed by at least two peers with expertise in the subject matter, revised based on those reviews, and reviewed by the editor before being accepted for publi- cation.
Grateful acknowledgment is given to the National Science and Technology Council’s Committee on the Environment and Natural Resources in the Executive Office of the President for providing guidance, to the sponsoring agencies, to the agency representatives named below who organized the symposium, to the international scientific community members who par- ticipated in the symposium, and to EC/R of Durham, NC, the contracting organization that provided logistical support for the symposium and this monograph.
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Hong Kong rocky shores are dominated by cyanobacterial biofilms composed of a diversity of species. Thirteen common species, belonging to seven genera, were isolated in pure culture in MN+ and MN- media under defined growth conditions from a semi-exposed shore in Hong Kong. The nutritional values (i.e., protein, carbohydrate and calorific value) of these 13 species were determined. All species showed high nutritional quality in terms of protein, carbohydrate and calorific value, however, overall nutritional value varied between the species. Species of Spirulina and Phormidium were most nutritious (highest nutritional values) whereas species of Calothrix and Lyngbya were the least nutritious. Microphagous molluscan grazer density and diversity were relatively high at the study site, despite the seemingly low biomass (as assessed by chlorophyll a concentration) of the biofilm. It is suggested that the high nutritional quality of cyanobacteria, together with their fast turnover rates can support high levels of secondary production (biomass of grazers). The high nutritional quality of cyanobacteria on tropical, cyanobacteria-dominated, rocky shores is therefore of great importance in the benthic food web.
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Seaweeds have received huge interest in recent years given their promising potentialities. Their antioxidant, anti-inflammatory, antitumor, hypolipemic, and anticoagulant effects are among the most renowned and studied bioactivities so far, and these effects have been increasingly associated with their content and richness in both primary and secondary metabolites. Although primary metabolites have a pivotal importance such as their content in polysaccharides (fucoidans, agars, carragenans, ulvans, alginates, and laminarin), recent data have shown that the content in some secondary metabolites largely determines the effective bioactive potential of seaweeds. Among these secondary metabolites, phenolic compounds feature prominently. The present review provides the most remarkable insights into seaweed research, specifically addressing its chemical composition, phytopharmacology, and cosmetic applications.
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Current Status of the Algae Production Industry in Europe: An Emerging Sector of the Blue Bioeconomy
The EU Bioeconomy Strategy aims to support the sustainable growth and development of the EU bio-based sectors while creating jobs, innovation and services. Despite the recognized potential of the algae biomass value chain, significant knowledge gaps still exist regarding the dimension, capability, organization and structure of the algae production in Europe. This study presents and analyses the results of a comprehensive mapping and detailed characterization of the algae production at the European scale, encompassing macroalgae, microalgae, and the cyanobacteria Spirulina. This work mapped 447 algae and Spirulina production units spread between 23 countries, which represents an important addition to the reported number of algae producing countries. More than 50% of these companies produce microalgae and/or Spirulina. Macroalgae production is still depending on harvesting from wild stocks (68% of the macroalgae producing units) but macroalgae aquaculture (land-based and at sea) is developing in several countries in Europe currently representing 32% of the macroalgae production units. France, Ireland, and Spain are the top 3 countries in number of macroalgae production units while Germany, Spain, and Italy stand for the top 3 for microalgae. Spirulina producers are predominantly located in France, Italy, Germany, and Spain. Algae and Spirulina biomass is directed primarily for food and food-related applications including the extraction of high-value products for food supplements and nutraceuticals. Algae production in Europe remains limited by a series of technological, regulatory and market-related barriers. Yet, the results of this study emphasize that the European algae sector has a considerable potential for sustainable development as long as the acknowledged economic, social and environmental challenges are addressed.
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Even with seaweed aquaculture growing rapidly over the last decade, global demand for seaweed-based products has surpassed supply. There is a large and diverse array of applications and uses of macroalgal products. The seaweed industry is estimated to have an annual value of some US$6 billion, the largest share of which (US$5 billion) is human food products. The remaining US$1 billion is largely based on seaweed extracts, such as hydrocolloids for use in animal feeds, fertilizers and bioactives.
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