Fucoxanthin is the main carotenoid produced in brown algae as a component of the light-harvesting complex for photosynthesis and photoprotection. In contrast to the complete elucidation of the carotenoid biosynthetic pathways in red and green algae, the biosynthetic pathway of fucoxanthin in brown algae is not fully understood. Recently, two models for the fucoxanthin biosynthetic pathway have been proposed in unicellular diatoms; however, there is no such information for the pathway in brown seaweeds to date. Here, we propose a biosynthetic pathway for fucoxanthin in the brown seaweed, Ectocarpus siliculosus, derived from comparison of carotenogenic genes in its sequenced genome with those in the genomes of two diatoms, Thalassiosira pseudonana and Phaeodactylum tricornutum. Currently, fucoxanthin is receiving attention, due to its potential benefits for human health. Therefore, new knowledge regarding the medical and nutraceutical properties of fucoxanthin from brown seaweeds is also summarized here.
Digital library
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The Line Islands are calcium carbonate coral reef platforms located in iron-poor regions of the central Pacific. Natural terrestrial run-off of iron is non-existent and aerial deposition is extremely low. However, a number of ship groundings have occurred on these atolls. The reefs surrounding the shipwreck debris are characterized by high benthic cover of turf algae, macroalgae, cyanobacterial mats and corallimorphs, as well as particulate-laden, cloudy water. These sites also have very low coral and crustose coralline algal cover and are call black reefs because of the dark-colored benthic community and reduced clarity of the overlying water column. Here we use a combination of benthic surveys, chemistry, metagenomics and microcosms to investigate if and how shipwrecks initiate and maintain black reefs. Comparative surveys show that the live coral cover was reduced from 40 to 60% to o10% on black reefs on Millennium, Tabuaeran and Kingman. These three sites are relatively large (40.75 km2). The phase shift occurs rapidly; the Kingman black reef formed within 3 years of the ship grounding. Iron concentrations in algae tissue from the Millennium black reef site were six times higher than in algae collected from reference sites. Metagenomic sequencing of the Millennium Atoll black reef-associated microbial community was enriched in iron-associated virulence genes and known pathogens. Microcosm experiments showed that corals were killed by black reef rubble through microbial activity. Together these results demonstrate that shipwrecks and their associated iron pose significant threats to coral reefs in iron-limited regions.
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There is a pressing need to elevate the debate on the future of aquaculture and to place this in the context of other animal food production systems, including wild capture fi sheries. Between 1970 and 2008 aquaculture production grew at an annual average rate of 8.4% and remains among the fastest growing food production sectors in the world. But with global demand for aquatic food products continuing apace, there are worries about the development trajectory of aquaculture. Of particular concern for Conservation International and many others is whether and how further growth can be met in ways that do not erode biodiversity or place unacceptable demands on ecological services. In this context, the potential for aquaculture to reduce pressure on wild capture fi sheries by meeting global demand for aquatic food products is also important.
Directed towards helping inform and stimulate policy debate, this report provides a global review and analysis of these issues for both coastal and freshwater aquaculture. Such debate is needed to help ensure that the current and future potential benefi ts of the burgeoning aquaculture sector are captured and the associated costs minimized. The report begins with an overview of the current status of world aquaculture. It then goes on to describe an approach for estimating the current combined biophysical resource demands of aquaculture for producer countries and regions. Following a comparison of these results with those available for other animal food production sectors the report then examines the consequences of likely future trends in production on the environmental impacts of aquaculture. Finally, the policy implications of the report’s fi ndings are discussed along with the research agenda that should be pursued to meet the challenge of sustainable food production.
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Carbon offsetting—receiving credit for reducing, avoiding, or sequestering carbon—has become part of the portfolio of solutions to mitigate carbon emissions, and thus climate change, through policy and voluntary markets, primarily by land-based re- or afforestation and preservation [1, 2]. However, land is limiting, creating interest in a rapidly growing aquatic farming sector of seaweed aquaculture [3, 4, 5]. Synthesizing data from scientific literature, we assess the extent and cost of scaling seaweed aquaculture to provide sufficient CO2eq sequestration for several climate change mitigation scenarios, with a focus on the food sector—a major source of greenhouse gases [6]. Given known ecological constraints (nutrients and temperature), we found a substantial suitable area (ca. 48 million km2) for seaweed farming, which is largely unfarmed. Within its own industry, seaweed could create a carbon-neutral aquaculture sector with just 14% (mean = 25%) of current seaweed production (0.001% of suitable area). At a much larger scale, we find seaweed culturing extremely unlikely to offset global agriculture, in part due to production growth and cost constraints. Yet offsetting agriculture appears more feasible at a regional level, especially areas with strong climate policy, such as California (0.065% of suitable area). Importantly, seaweed farming can provide other benefits to coastlines affected by eutrophic, hypoxic, and/or acidic conditions [7, 8], creating opportunities for seaweed farming to act as “charismatic carbon” that serves multiple purposes. Seaweed offsetting is not the sole solution to climate change, but it provides an invaluable new tool for a more sustainable future.
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We want to warmly welcome all participants to the Symposium on Environmental Engineering (SEE), held in the scope of the 4th Doctoral Congress (DCE21) hosted at the Faculty of Engineering of the University of Porto (FEUP), Porto, Portugal, on the 28th and 29th of June 2021. This time, due to the COVID-19 pandemic, the event is entirely conducted in virtual mode. This Symposium is organized by PhD students of the Doctoral Program in Environmental Engineering (PDEA) at FEUP, with the support of the professors. The Environmental Engineering Symposium covers broad, important and multidisciplinary themes, with oral and poster presentations comprising a wide range of topics included in the UN Sustainable Development Goals: ▪ Clean Water: Emerging Pollutants, Monitoring and Treatment; ▪ Air Quality: Emissions, Assessment and Health Safety; ▪ Waste Management and Circular Economy; ▪ Energy, Sustainability and Innovation: Products, Technologies and Climate Change Mitigation. It is with great honour that we welcome the Keynote Speakers, who elevate the Symposium with their participation and by highlighting current hot topics of environmental engineering: ▪ Dr. Despo Fatta-Kassinos, a leading international scientist in water quality and management, Professor at the Department of Civil and Environmental Engineering and Director of Nireas-International Water Research Center of the University of Cyprus; ▪ Dr. Xavier Querol Carceller, a worldwide recognized scientist in air quality from the Institute of Environmental Assessment and Water Research (IDAEA) in Spain, who received several awards, among which the 2013 Award “Rey Jaime I” for the Protection of the Environment and the 2020 National Research Award “Alejandro Malaspina” on Natural Resources; ▪ Dr. Nuno Lacasta, the Executive Board President (CEO) of the Portuguese Environment Agency – APA. In addition, we thank the PDEA alumni at the round table session, which also provide a noteworthy contribution to the Symposium by emphasizing the role and importance of a PhD in Environmental Engineering. The Organizing Committee received over 65 communications, a new record. A total of 26 oral and 40 poster presentations of great quality were selected. We take this opportunity also to acknowledge all authors for their contributions, the Scientific Committee and the participant Institutions for their support. A final thank you to our Symposium’s sponsors: LEPABE, LSRE-LCM, CERENA and MIEA. Thank you all!! Porto, June 2021
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Gracilaria is a commercially valuable agarophyte and its many species are distributed throughout temperate and tropical seas. Gracilaria edulis is the common agar yielding seaweed in India. The life history of Gracilaria consists of an alternation of isomorphic phase with unisexual gametophyte.
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Multiple health benefits have been ascribed to brown seaweeds that are used traditionally as dietary component mostly in Asia. This systematic review summarizes information on the impact of brown seaweeds or components on inflammation, and inflammation-related pathologies, such as allergies, diabetes mellitus and obesity. We focus on oral supplementation thus intending the use of brown seaweeds as food additives. Despite the great diversity of experimental systems in which distinct species and compounds were tested for their effects on inflammation and immunity, a remarkably homogeneous picture arises. The predominant effects of consumption of brown seaweeds or compounds can be classified into three categories: (1) inhibition of reactive oxygen species, known to be important drivers of inflammation; (2) regulation, i.e., in most cases inhibition of proinflammatory NF-κB signaling; (3) modulation of adaptive immune responses, in particular by interfering with T-helper cell polarization. Over the last decades, several inflammation-related diseases have increased substantially. These include allergies and autoimmune diseases as well as morbidities associated with lifestyle and aging. In this light, further development of brown seaweeds and seaweed compounds as functional foods and nutriceuticals might contribute to combat these challenges.
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The therapeutic potential of Sargassum siliquosum grown in Australian tropical waters was tested in a rat model of metabolic syndrome. Forty-eight male Wistar rats were divided into four groups of 12 rats and each group was fed a different diet for 16 weeks: corn starch diet (C); high-carbohydrate, high-fat diet (H) containing fructose, sucrose, saturated and trans fats; and C or H diets with 5% S. siliquosum mixed into the food from weeks 9 to 16 (CS and HS). Obesity, hypertension, dyslipidaemia, impaired glucose tolerance, fatty liver and left ventricular fibrosis developed in H rats. In HS rats, S. siliquosum decreased body weight (H, 547 ± 14; HS, 490 ± 16 g), fat mass (H, 248 ± 27; HS, 193 ± 19 g), abdominal fat deposition and liver fat vacuole size but did not reverse cardiovascular and liver effects. H rats showed marked changes in gut microbiota compared to C rats, while S. siliquosum supplementation increased gut microbiota belonging to the family Muribaculaceae. This selective increase in gut microbiota likely complements the prebiotic actions of the alginates. Thus, S. siliquosum may be a useful dietary additive to decrease abdominal and liver fat deposition.
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Until the late 1980s, there was little targeted harvest of bull kelp (Nereocystis luetkeana) in California, except as a small component of the localized edible seaweed industry. In central California, Nereocystis and Macrocystis often form mixed beds and it is likely bull kelp would have been incidentally taken during harvest of those beds, but not recorded separately on harvest records. Department records indicate about 19 tons of kelp, probably a mixture of Macrocystis and Nereocystis, were harvested from what is presently bed 302 off the Bodega Bay–Tomales Bay area between 1993 and 1999. All of this kelp was used by local abalone culturists. Other uses of bull kelp include pickling the stipe and marketing it as a specialty food product, and using the dried parts for arts and crafts. In southern Oregon, bull kelp was harvested from Orford Reef in the mid-1990s as an ingredient in liquid fertilizer. The Oregon Division of State Lands has since discontinued permitting that harvest
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PowerPoint as PDF on our energy footprints, sustainability and aquaculture.
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Marine Agronomy Group, CAFNRM, UH-Hilo
200 W. Kawili st., HI 96720, USA
Contact: Marine.Agronomy.Group@gmail.com
Funding for this web portal is provided by the World Wildlife Fund and the University of Hawaii-Hilo.