Macroalgae (aka seaweed) - the quintessential ocean crop
- ~15,000 different species growing in a wide range of geographies
- Fast growth rate
- Mostly carbohydrate & protein
- Amenable to cultivation & harvest
Digital library
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Seaweeds or marine macro algae are primitive non-flowering plants without true root, stem and leaves. They form one of the commercially important marine living renewable resources. They are the only source for the production of phytochemicals such as agar, carrageenan and algin. Seaweeds occur in the intertidal, shallow and deep waters of the sea upto 180m depth and also in estuaries and backwaters. They grow on rocks, dead corals, stones, pebbles, solid substrata and on other plants.
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The Brazilian seaweed assemblage currently comprises 770 taxa, distributed along 7,367 km of coastline with highly diverse ecological conditions, suggesting a high biotechnological potential for these species. Studies on seaweed biotechnology in Brazil began in 1948 and have produced extensive published information that is presently scattered in many sources. This manuscript presents an overview of biotechnology studies on seaweeds that were carried out in Brazil, from the earliest through 2012, with the purpose of directing new studies in this field. The studies analyzed were retrieved from the curricula of Brazilian seaweed researchers, centralized in the public database Currículo Lattes, supported by the Brazilian National Council of Technological and Scientific Development (CNPq). Scientific papers dealing with biological activities of natural extracts from native and some non-native seaweeds were selected. The survey was complemented by a search for older references cited in the first group. Together, the studies extend over 64 years, totaling 364 scientific papers investigating the potential of 160 seaweed taxa, including tests for 6 antibiotic activities, 11 categories of other biological activities, and a wide range of natural products. In general, the studies focused on antiinflammatory, antinociceptive, and antiviral activities, and some characterized the effects of molecules, including sulfated polysaccharides, lectins, and terpenes.
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The ecological traits of the intertidal rocky shore seaweed communities were investigated for the site-specific development of the Sustainable Seaweed Integrated Aquaculture System (SSIAS) in Korea. Monthly phenological surveys of the intertidal communities were conducted in 2002 to obtan information on the wild seaweed species for their application to the SSIAS. The changes of the dominant species composition and their fresh weight and coverage were prominent among the seasons and sampling sites. Generally, brown algae, Laminaria japonica and Sargassum sp., were dominant in the winter; red algae were abundant in the spring and the autumn. Green alga, Ulva pertusa, showed the broadcast coverage year around. The C/N ratios of seaweeds and the ambient nitrogen concentrations were positively correlated.
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Seaweed Energy Solutions AS (SES) has announced that it has reached an agreement to acquire 100 per cent of Denmark's Seaweed Seed Supply AS (SSS), a move that sharply reinforces SES' position as Europe's leading player in large-scale seaweed cultivation for renewable energy and other uses.
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This study manipulated the carbon-to-nitrogen ratio (C:N) of seaweed composts by varying the proportion of high N green seaweed (Ulva ohnoi) and high C sugarcane bagasse to assess their quality and suitability for use in agricultural crop production. Seaweed-bagasse mixes that had an initial C:N ratio greater than 18:1 (up to 50:1) could be transformed into a mature compost within 16 weeks. However, only composts with a high seaweed content and therefore low initial C:N (18 and 22:1) supported a consistently high rate of plant growth, even at low application rates. Sugarcane grown in these high seaweed composts had a 7-fold higher total above-ground biomass than low seaweed composts and a 4- fold higher total above-ground biomass than sugarcane grown in commercial compost that did not contain seaweed. Overall, the optimal initial C:N ratio for seaweed-based compost was 22:1 which corresponds to 82 % seaweed on a fresh weight basis. This ratio will produce a high quality mature compost whilst also ensuring that a high proportion of the nitrogen (>90 %) in the Ulva biomass is retained through the composting process.
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Background: Seaweed is a popular traditional food in Japan and is a rich source of bioactive metabolites. The neuroprotective properties of seaweed have attracted attention; to date, however, there has been no epidemiological evidence regarding the relationship between seaweed consumption and depression. The current cross-sectional study investigated the association between seaweed consumption and depressive symptoms during pregnancy in Japan.
Methods: Study subjects were 1745 pregnant women. Depressive symptoms were defined as present when subjects had a Center for Epidemiologic Studies Depression Scale score of 16 or higher. Dietary consumption during the preceding month was assessed using a self-administered diet history questionnaire. Adjustment was made for age; gestation; region of residence; number of children; family structure; history of depression; family history of depression; smoking; secondhand smoke exposure at home and at work; job type; household income; education; body mass index; and intake of fish and yogurt.
Results: The prevalence of depressive symptoms during pregnancy was 19.3%. After adjustment for possible dietary and non-dietary confounding factors, higher seaweed consumption was independently associated with a lower prevalence of depressive symptoms during pregnancy: the adjusted odds ratios (95% confidence intervals) for depressive symptoms during pregnancy in the first, second, third, and fourth quartiles of seaweed consumption were 1 (reference), 0.72 (0.51 − 1.004), 0.71 (0.50 − 1.01), and 0.68 (0.47 − 0.96), respectively (P for trend = 0.03).
Conclusions: The present results suggest that seaweed consumption may be inversely associated with the prevalence of depressive symptoms during pregnancy in Japanese women.
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The slimy ocean strands that tangle onto your body while swimming may have a new purpose. Researchers are turning towards kelp and seaweed as a viable fuel option in replacing biofuel made from crops. The new form of biofuel would provide a solution to alleviate over-farming and protect freshwater sources.
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- Seaweed could hold the key to cutting methane emissions from cow burps
- From Canada to the world
- Fighting climate change, feeding people
- Where can we grow all the seaweed?
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The Shetland Seaweed Growers Project
Project Funding and Objectives
The Shetland Seaweed Growers project was funded by the Coastal Communities Fund and undertaken at the NAFC Marine Centre in Scalloway, Shetland from June 2014 to December 2016. The project explored whether growing seaweed on a commercial scale is a feasible option within Shetland, in order to create jobs, generate income for the community and present new business opportunities for Shetland companies. Other aims of Shetland Seaweed Growers included supporting local businesses to incorporate seaweed in their products and to increase public awareness of seaweeds, their ecology and their uses.
Partners and Industry Associates
Scottish Sea Farms Ltd. was a commercial partner in the project and generously provided a six hectare licensed sea-site for growing seaweed at Sandsound South in Shetland. They also provided use of a work-boat, skipper and crew to help set up the necessary longlines; seadeploy the hatchery-grown seedlings, and harvest and sample the resulting seaweed crop. East Voe Shellfish Ltd. were industry associates of the project who were contracted to carry out the same tasks listed above on a second seaweed sea-site at Lea of Trondra, Shetland that is owned by the NAFC Marine Centre. Grieg Seafoods Ltd. kindly donated some drying/smoking racks to the project to allow the NAFC Marine Centre to dry bulk quantities of seaweed.
Seaweed Uses
Seaweed is used by many maritime communities in a variety of ways from simple food sources and fertilisers to more complex products such as gels, medicines, cosmetics and alginates.
- Seaweed has been a food source for thousands of years, forming a staple part of the diet in countries like Japan, Korea and China. Particularly important seaweeds to the Japanese market belong to the Porphyra, Laminaria, Saccharina and Undaria genera. In European countries, seaweed has often been used as an alternative food source during hard times while Welsh ‘laver’ (Porphyra umbilicalis) and ‘dulse’ (Palmaria palmata), are considered delicacies by many.
- Historically, kelp was burned on a massive scale (including in Orkney and Shetland) to produce ‘potash’ (potassium salts) for fertilizer. This practice has now been replaced by world-wide mining of potash ores.
- Alginates are extracted from brown seaweed and used to create gels for foams, stabilisers, emulsifiers and industrial gums. They are also used by the cosmetic and health industries for body wraps, facial masks, soaps, shampoo and conditioners, make-up gels/creams, indigestion remedies, encapsulating particles and absorbent wound-dressings, along with a range of other products.
- Liquid seaweed extracts from brown seaweeds are used as mineral and vitamin supplements in agriculture, horticulture, animal husbandry and, more recently, in human health products.
- Agar is made from certain red seaweeds. In addition to being used in food production, it is universally used in laboratories as a substrate for bacteria cultures. There is currently no satisfactory substitute for laboratory agar.
- Carrageenans are also extracted from red seaweed and are widely used in the food industry, for their gelling, thickening, and stabilizing properties. Their main application is in dairy and meat products, due to their strong binding to food proteins.
- More recently the anti-bacterial and anti-cancer properties of seaweed derivatives such as fucoidan and laminarin are being investigated by the pharmaceutical and medical professions.
- There are numerous edible species that grow around the British Isles, including Shetland. Brown seaweeds are the most abundant, with kelps and fucoids such as Laminaria digitata, Alaria esculenta, Fucus spiralis, Fucus vesiculosus and Ascophyllum nodosum. Dulse and Irish moss are edible red seaweeds that are widely harvested in Ireland.
Shetland Businesses Currently Making Use of Seaweed:
The Shetland Seaweed Growers project encouraged local businesses to diversify by incorporating seaweed grown by the project team into some of their products and/or undergoing training in sustainable harvesting of wild seaweed. Examples of participating companies include:
Artisan Island Cheese, Hoofields, Lerwick. (Caroline Henderson).
https://food.list.co.uk/place/57672-artisan-island-cheese/
Mirrie Dancers Chocolatier, Lerwick (David Williams)
http://www.shetland.org/60n/blogs/posts/mirrie-dancers-chocolatier-launch ).
Orkney Soap, Kirkwall.
http://www.cope.ltd.uk/enterprises/orkney-soap
Saxa Vord Restaurant, Unst. (Steve Carter)
http://www.saxavord.com/food-and-drink.php
Shetlandeli, Bixter (Jill Franklin)
Shetland Distillery Company, Unst (Stuart Nickersen)
Shetland Fudge Company, Lerwick.
https://www.shetlandfudge.co.uk/
Shetland Garden Co., Lerwick (Ingrid Webb)
http://www.cope.ltd.uk/enterprises/shetlandgarden-co.
Shetland SeaSalt Co., Scalloway (Akshay Borges)
Shetland Soap Co., Lerwick (Ingrid Webb)
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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.