Large-scale Gracilaria cultivation can be an effective means of improving water quality and promoting a more sustainable mariculture industry in China. In tests, the seaweed Gracilaria lemaneiformis provided several beneficial functions. It was very effective in decreasing nitrogen and phosphorus loadings. The seaweed was also able to inhibit the growth of some microalgae and may increase dissolved oxygen in the water column.
Spatial claims concerning the rapidly growing European offshore wind sector give rise to various ideas for the multi-use application of wind farms. Seaweed is considered a promising feedstock for food and feed that could be produced at offshore wind farms. Concerns about risks resulting in liability claims and insurance premiums are often seen as show-stoppers to multi-use at offshore wind farms. In this study, key environmental risks of seaweed cultivation at offshore wind farms, identified through literature review, are characterized based on stakeholder consultation. The current approach to risk governance is evaluated to assess how it can handle the uncertain, complex, and/or ambiguous risks of multi-use. It is concluded that current risk governance for multi-use is poorly equipped to deal with the systemic nature of risks. Risk governance should be a joint effort of governments and private regulators. It can improve if it is based on an adaptive framework for risk assessment that can deal with complex, systemic risks. Furthermore, it should be flexible and inclusive, i.e., open to new incoming information and stakeholder input, and taking into account and communicate about the different stakes and values of the various parties involved. The importance of communication and inclusion must be recognized, which promotes participation of concerned stakeholders.
A significant challenge to the expansion of aquaculture production is controlling the outbreak of disease. Many farmers who experience the potential loss of stock from disease may choose to use chemotherapeutic agents to minimize their loss. It is generally understood that a disease in aquaculture is a combination of the health of the animal, the condition of the environment and the presence of a pathogen. From this concept there are a number of precautionary measures that farmers may practice to minimize disease outbreaks. The principles of Hazard Analysis Critical Control Point (HACCP) may be useful risk management tools to reduce pathogens, animal stress and the need for chemotherapeutic agents to control disease outbreaks on the farm.
The Seaweed Carrier mimics a natural seaweed, moving freely in the sea from a single mooring point. Testing with a small-scale carrier in Frøya in July 2011 reveals promise.
Scientists have created a genetically engineered microbe that turns the algae into low-carbon biofuel, but must make the technique commercially viable
Glyphosate-based herbicides are commonly used to combat weeds and unwanted grasses in many habitats in the Hawaiian Islands, including near freshwater, marine, and anchialine pond shorelines. Glyphosate is reported to degrade within a few days of application and to break down rapidly in soil, which suggests that it is safe for use near aquatic environments. However, glyphosate can be transported to coastal waters, especially during run-off events. Five native macroalgael and seagrass species and one introduced aquatic vascular plant found in coastal anchialine ponds or in the adjacent intertidal zone were exposed to freshly mixed solutions of a glyphosate-based herbicide in lab experiments. Chlorophyll absorbance and photosystem II (PSII) efficiency were measured after 5 to 7 days of incubation. At herbicide concentrations (0.225 to 1.8 g L−1 glyphosate) below the manufacturer’s lowest recommended concentration (3.6 g L−1 glyphosate), chlorophyll absorbance and PSII efficiency differed significantly from the control (0.0 g L−1 glyphosate). Native macroalgae and seagrasses in marine and anchialine aquatic habitats may be negatively affected by use of glyphosate herbicides to control shoreline weeds.
Species of the unicellular alga Dunaliella possess outstanding tolerance of a wide range of salinities. They can adapt to grow in salt media which range from less than 0.5 M to saturated salt solutions and withstand enormous osmotic shocks through a unique osmotic adaptation. The osmoregulating mechanism depends on photosynthetic production of glycerol, whose intracellular concentration varies in direct proportion to the extracellular salt concentration and reaches values in excess of 50% of the total dry weight of the cells. Dunaliella, and another halotolerant glycerol producing alga, Asteromonas gracilis, osmoregulate biochemically by controlling glycerol biosynthesis and degradation. 3 new enzymes, NADPH-dihydroxyacetone-reductase, dihydroxyacetone kinase and glycerol-1-phosphatase seem to be involved in the osmoregulatory response via glycerol in Dunaliella and Asteromonas. A hypothetical scheme of glycerol metabolism in these algae utilizing these enzymes is presented. Growth studies of Dunaliella indoors and outdoors showed that salt concentrations favoring maximal glycerol productivity are not identical with those required for maximal algal productivity. Maximal yield of glycerol occurred around 2 M NaCl while maximal algal productivity occurred below 0.5 M NaCl. Observed yields of glycerol in Dunaliella culture outdoors are compared with theoretically calculated maximal yield.
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Report by the Institution of Mechanical Engineers found that due to poor practices in harvesting, storage and transportation, as wellvas market and consumer wastage, it is estimated that 30–50% (or 1.2–2 billion tonnes) of all food produced never reaches a human stomach.
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.
