What is important is that the appropriate organisms are chosen based on the functionsthey have in the ecosystem, their economic value or potential, and their acceptance byconsumers. While IMTA likely occurs due to traditional or incidental, adjacent cultureof dissimilar species in some coastal areas (Troellet al., 2003), deliberately designedIMTA sites are, at present, less common. Moreover, they are presently simplifiedsystems, like fish/seaweed/shellfish. In the future, more advanced systems with severalother components for different functions, or similar functions but different size rangesof organic particles, will have to be designed (Chopin, 2006).The aim is to increase long-term sustainability and profitability per cultivation unit(not per species in isolation as is done in monoculture), as the wastes of one crop (fedanimals) are converted into fertilizer, food and energy for the other crops (extractiveplants and animals), which can in turn be sold on the market. Feed is one of the coreoperational costs of finfish aquaculture operations. Through IMTA, some of thefood, nutrients and energy considered lost in finfish monoculture are recaptured andconverted into crops of commercial value, while biomitigation takes place. In this wayall the cultivation components have an economic value, as well as a key role in servicesand recycling processes of the system, the harvesting of the three types of cropsparticipating in the export of nutrients outside of the coastal ecosystem.IMTA is considered more sustainable than the common monoculture systems – thatis a system of aquaculture where only one species is cultured – in that fed monoculturestend to have an impact on their local environments due to their dependence ofsupplementation with an exogenous source of food and energy without mitigation(Chopinet al., 2001). For some twenty years now, many authors have shown that thisexogenous source of energy (e.g. fish food) can have a substantial impact on organicmatter and nutrient loading in marine coastal areas (Gowen and Bradbury, 1987; Folkeand Kautsky, 1989; Chopinet al., 1999; Cromey, Nickell and Black, 2002), affectingthe sediments beneath the culture sites and producing variations in the nutrientcomposition of the water column (Chopinet al., 2001).
Digital library
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The story of seaweed will take us from a medicine hut in southern Chile to a high-tech seaweed nursery in Stamford, Connecticut, and from biofuels to beer, as we discover the surprising history and bright future of marine vegetables. Along the way, we uncover the role kelp can play in supporting U.S. fishermen, cleaning up coastal waters, and even helping make salmon farms more sustainable.
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The secretariat of the Pacific Community (SPC) commissioned the Institute of Marine Resources (IMR) of The University of the South Pacific to: 1) conduct a literature review of the introductions of the seaweed Kappaphycus alvarezii to Pacific Islands Countries and the current state of seaweed farming in these countries and 2) to field-test their proposed quarantine protocol for introducing K. alvarezii to new locations.
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PDF of pictures that shows good harvesting on a kelp farm.
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In previous editions of this newsletter, we considered topics by category. Beer, for example, or meat, or milk, or coffee. This edition is different, because we’re talking about seaweed, specifically kelp, which is a bit magical, because it can reduce carbon emissions in multiple categories of the food system.
My kelp journey began in 2014 with a chance encounter in a hot tub on a roof in Monterey, where I enjoyed a cocktail with leading fish authority Paul Greenberg. The next morning, I joined Greenberg, who was researching rock fish, scuba diving in the amazing (and amazingly cold) kelp forest in Monterey Bay. I don’t remember much about the rock fish, but the kelp forrest was memorable; it felt like a canvas on which the otters, the fish and the divers were being painted.
My kelp journey continues seven years and 3,306 miles later. On Monday I arrived in Portland, Maine, which, like Asheville, is filled with microbreweries. It is a fun place with great seafood and salty characters. I was brought there by Casey Emmett, who came to my attention in the two-part series on seaweed in the How to Save a Planet podcast.
Casey and I boarded Stewart Hunt’s lobster boat and harvested about 6000 lbs of sugar kelp on a gorgeous cool sunny day. So much fun to get wet and dirty and help hard working people launch what will one day be a huge industry.
How can kelp help?
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The design of keys for identification of algae is based on the external form with addition of obvious cytological details Form alone can be used for large thalloid algae. Form combined with pigmentation and chromatophore shape can lead to the identification of many algae. It is often necessary to examine the apex of branches to determine the manner of growth.
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This work developed a laboratory prototype methodology for cost-effective, water-sparing drip-irrigation of seaweeds, as a model for larger-scale, on-land commercial units, which we envision as semi-automated, inexpensive polyethylene sheet-covered bow-framed greenhouses with sloping plastic covered floors, water-collecting sumps, and pumped recycling of culture media into overhead low-pressure drip emitters. Water droplets form on the continually wetted interior plastic surfaces of these types of greenhouses scattering incoming solar radiation to illuminate around and within the vertically-stacked culture platforms. Concentrated media formulations applied through foliar application optimize nutrient uptake by the seaweeds to improve growth and protein content of the cultured biomass. An additional attribute is that seaweed growth can be accelerated by addition of anthropogenic CO2-containing industrial flue gases piped into the head-space of the greenhouse to reuse and recycle CO2 into useful algal biomass. This demonstration tested three different drip culture platform designs (horizontal, vertical and slanted) and four increasing fertilizer media concentrations (in seawater) for growth, areal productivity, and thallus protein content of wild-collected Ulva compressa biomass, against fully-submerged controls. Cool White fluorescent lights provided 150–200 μmol photon m-2 s-1 illumination on a 12/12 hr day/night cycle. Interactive effects we tested using a four-level single factorial randomized block framework (p<0.05). Growth rates and biomass of the drip irrigation designs were 3–9% day-1 and 5–18 g m-2 day-1 (d.w.) respectively, whereas the fully-submerged control group grew better at 8–11% per day with of 20–30 g m-2 day-1, indicating further optimization of the drip irrigation methodology is needed to improve growth and biomass production. Results demonstrated that protein content of Ulva biomass grown using the vertically-oriented drip culture platform and 2x fertilizer concentrations (42:16:36 N:P:K) was 27% d.w., approximating the similarly-fertilized control group. The drip methodology was found to significantly improve gas and nutrient mass transfer through the seaweed thalli, and overall, the labor- and-energy-saving methodology would use a calculated 20% of the seawater required for conventional on-land tank-based tumble culture.
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Background: Common cold is caused by a variety of respiratory viruses. The prevalence in children is high, and it potentially contributes to significant morbidity. Iota-carragenan, a polymer derived from red seaweed, has reduced viral load in nasal secretions and alleviated symptoms in adults with common cold.
Methods: We have assessed the antiviral and therapeutic activity of a nasal spray containing iota-carrageenan in children with acute symptoms of common cold. A cohort of 153 children between 1-18 years (mean age 5 years), displaying acute symptoms of common cold were randomly assigned to treatment with a nasal spray containing iota-carrageenan (0.12%) as verum or 0.9% sodium chloride solution as placebo for seven days. Symptoms of common cold were recorded and the viral load of respiratory viruses in nasal secretions was determined at two consecutive visits.
Results: The results of the present study showed no significant difference between the iota carrageenan and the placebo group on the mean of TSS between study days 2-7. Secondary endpoints, such as reduced time to clearance of disease (7.6 vs 9.4 days; p = 0.038), reduction of viral load (p = 0.026), and lower incidence of secondary infections with other respiratory viruses (p = 0.046) indicated beneficial effects of iota-carrageenan in this population. The treatment was safe and well tolerated, with less side effects observed in the verum group compared to placebo.
Conclusion: In this study iota-carrageenan did not alleviate symptoms in children with acute symptoms of common cold, but significantly reduced viral load in nasal secretions that may have important implications for future studies.
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Biomethane produced from seaweed is a third generation renewable gaseous fuel. The advantage of seaweed for biofuel is that it does not compete directly or indirectly for land with food, feed or fibre production. Furthermore, the integration of seaweed and salmon farming can increase the yield of seaweed per hectare, while reducing the eutrophication from fish farming. So far, full comprehensive life cycle assessment (LCA) studies of seaweed biofuel are scarce in the literature; current studies focus mainly on microalgal biofuels. The focus of this study is an assessment of the sustainability of seaweed biomethane, with seaweed sourced from an integrated seaweed and salmon farm in a north Atlantic island, namely Ireland. With this goal in mind, an attributional LCA principle was applied to analyse a seaweed biofuel system. The environmental impact categories assessed are: climate change, acidification, and marine, terrestrial and freshwater eutrophication. The seaweed Laminaria digitata is digested to produce biogas upgraded to natural gas standard, before being used as a transport biofuel. The baseline scenario shows high emissions in all impact categories. An optimal seaweed biomethane system can achieve 70% savings in GHG emissions as compared to gasoline with high yields per hectare, optimum seaweed composition and proper digestate management. Seaweed harvested in August proved to have higher methane yield. August seaweed biomethane delivers 22% lower impacts than biomethane from seaweed harvested in October. Seaweed characteristics are more significant for improvement of biomethane sustainability than an increase in seaweed yield per unit area.
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“When I was growing up, if you went to a lūʻau, you would know who prepared the food and what area it came from by just knowing the taste of the limu and the kinds of limu that were utilized. Basically, you could tell where the families came from by the raw stuf they made,” says Malia Akutagawa, who was raised on the east end of Molokaʻi. Now 48 years old and an assistant professor of law and Hawaiian Studies with both the University of Hawaiʻi at Mānoa’s William S. Richardson School of Law and the Kamakakūokalani Center for Hawaiian Studies in the Hawai‘inuiākea School of Hawaiian Knowledge, Malia Akutagawa was taught by her grandmother from a young age how to pick limu. She says her grandmother, Katharine Kalua Hagemann Akutagawa, or Grandma Kitty, was known as one of the best limu pickers on the island. Grandma Kitty learned from Tūtū Hapa Kalua, who was cousin to Malia’s great grandmother, Haʻaheo.
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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.