The low volume batches of highly-concentrated wastewater discharged from land-based marine recirculating aquaculture systems are ideally suited for treatment by halophyte planted constructed wetlands. To evaluate the role of plants and the effect of planting density on yield and performance in small-scale saline constructed wetlands (CWs), NH4 + + NO3 − + NO2 − = total dissolved inorganic nitrogen (TDIN) and dissolved inorganic phosphorus (DIP) were measured at regular intervals over 24 h periods. CWs were planted with the halophyte Salicornia europaea at high- and low-densities and were compared to the performance of unplanted controls. S. europaea plants were cropped regularly to assess potential commercial yield at the two densities. There was no significant effect of planting density on performance or crop yields and planted beds consistently outperformed the control beds removing 62.0 ± 34.6 mmol N m−2 d−1 (34–73% of influent TDIN) compared to 23.0 ± 26.8 mmol N m−2 d−1 (−1% to 41% of influent TDIN) by control beds. Results for DIP were less clear, significant removal occurred only once, with reduction of 18.3 ± 5.0 mmol P m−2 d−1 by planted beds and 18.1 ± 2.6 mmol P m−2 d−1 by the unplanted controls. The results demonstrate the effectiveness of halophyte-planted CW in treatment of marine aquaculture wastewater
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Alaria esculenta populations from six different geographical locations on the Irish coast were examined for hybridization abilities, growth rates and genetic make-up with a view towards identifying a fast-growing strain suitable for aquaculture. Hybridization experiments under laboratory conditions with the three most geographically dispersed populations showed that all cross combinations were interfertile, although differences were found in survival, and in blade and hapteron morphology. A comparison of relative growth rates showed significant differences amongst the self-crosses and hybrids. The data of the hybridization experiments and growth rates under laboratory conditions show that the best population for the purpose of seaweed aquaculture are the Slea Head and Corbet Head self-crosses and their hybrids. Genetic fingerprinting of the internal transcribed spacer of the ribosomal DNA of five A. esculenta isolates from geographically separated populations in Ireland revealed no restriction length polymorphisms between the tested isolates and show that the A. esculenta populations around the Irish coast are clearly genetically homogenous in respect of the DNA region examined. The genetic analysis, interfertility of the populations, morphology and growth rates are discussed with a view to potential cultivation.
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As the world's population continues to grow, the way in which ocean industries interact with ecosystems will be key to supporting the longevity of food and social securities. Aquaculture is crucial to the future supply of seafood, but challenges associated with negative impacts could impede increased production, especially production that is efcient and safe for the environment. Using the typology established by The Economics of Ecosystems and Biodiversity Initiative, we describe how marine aquaculture could be influential in supporting ecosystem services beyond solely the production of goods, through provisioning services, regulating services, habitat or supporting services, and cultural services. The provision of these services will vary, depending on functional traits of culture species, biotic and abiotic characteristics of the surrounding environment, farm design, and operational standards. Increasing recognition, understanding, and accounting of ecosystem service provision by mariculture through innovative policies, financing, and certification schemes may incentivize active delivery of benefits and may enable efects at a greater scale.
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Marine algal ecology today faces many of the same problems as ecology in general, e.g. lack of generality of experimental results, the difficulty of making long-term predictions, and an apparent lack of agreement as to what constitutes the proper or 'acceptable' way of doing this particular component of science. These problems, if real, affect marine algal ecology everywhere but, in different geographical areas, specific problems also occur; science in parts of Asia has some problems different from those in other parts of the world. Since its inception, research in marine algal ecology has been motivated by many factors, ranging from traditional needs, to curiosity, to survival, to new technology, and economic needs. Each of these has shaped the questions that have been asked by, and the level ofsupportsociety has been willing to supply to, ecology. For example the requisites oftradition pushed marine ecology to ask questions about food and ceremonial biota, and our fears today about loss of biota are pushing for answers to questions about the means of preserving biodiversity. The limitations of many marine ecological studies have been pointed out by different individuals. Their comments have been valuable in forcing us to examine what we are doing as marine ecologists, and how we are doing it. Ecology, and marine algal ecology with it, has been accused of carrying out small-scale studies that have no greater generality than the sites at which the studies were done, and of using statistical procedures that are wrong or inappropriate; also, there is disagreement within the ecological community of how to correct for these 'faults'. Some of the problems arise due to the nature of our particular science, e.g. working with organisms with differing genetic makeup and sensitivity of experimental results to small changes in initial conditions. Other problems are more likely due to the individuals doing the science, e.g. an inability to be an 'expert' on all areas of knowledge required for a modem ecologist (taxonomy, experimental design, data analysis, etc.), and perhaps an unwillingness to recognize that in some instances different methods of data analysis are applicable and valid. As ecologists, we must come to grip with these problems, both for the sake of our science, and for our own sake as practicing ecologists.
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The goal of this study was to evaluate flow-cytometric techniques for isolating individual kelp meiospores into 96-welled plates. Previously reported low success rates for sorting tens of thousands of meiospores at a time have been improved by technological developments, specifically, the low nozzle pressure of the commercially available, JSAN (Bay Bioscience Co. Ltd) instrument. We monitored growth and gametophyte development post-sorting for 10 months. Our data demonstrate that successful kelp meiospore isolations of up to 76% viability can be achieved with flow-cytometry. This method can save time as compared to traditional, manual isolations using pipettes and improves confidence that self-fertilized individuals will not contaminate specific crosses of resulting gametophytes. Our results highlight a new application for the flow cytometer to produce clonal kelp gametophytes with direct applications for germplasm and culture collection development.
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As the earth’s population continues to rise, concern over the availability of resources is increasing. Hunger, health, and availability of fuels are just some of the problems the world will need to solve. Currently, traditional agriculture plays a central role in food and fuel production, but growing population limits availability of the farmland required by these crops. With these problems in mind, marine agronomy, using oceans to produce usable crops, such as seaweed, becomes an appealing option. Seaweed offers not only a source of food, but also has some useful applications in pharmaceuticals and biofuels.
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This work shows the technical and economical aspects of seaweed farming for the production of phycocolloids or marine gums. Two different cultivation systems were used in four different sites inhabited by Wayúu fisherman communities in the townships of Cabo de La Vela and Carrizal, Guajira Peninsula, Colombia. The productivity and the growth rate of three commercial important macroalgae species, as well as the production costs, investment and returns of 0,5 ha marine farms, taking into consideration the design and construction of cultivation units made with cheap and available materials. The implementation of these farming systems could lead for the technological transfer of the locals. The income obtained through seaweed farming could benefit a large part of the coastal community as an additional and complementary cash crop to their traditional activities, including artisan fishing and goat rising, where the majority thrives in conditions of extreme poverty with the highest unmet basic needs index of the country.
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Anaerobic digester effluent containing high levels of ammonia poses a threat to the environment. To hinder this issue, a modern and promising treatment method incorporates both microalgae and their bioconversion potential. When culturing Chlorella vulgaris at a 1:7 digestate supernatant dilution ratio, biomass concentration was 1.33 g L−1 and 66% of ammonia nitrogen was removed. Furthermore, a prior nitrogen-starved seed method, namely over-compensation strategy, was applied to improve both biomass production and nutrient removal. By using nitrogen-starved seeds after a 48 h nitrogen-free stimulation, biomass yield increased by 1.7-times to 2.56 g L−1. Simultaneously, ammonia nitrogen and total phosphorus removal efficiencies reached 99% and 97% respectively. The enhanced production corresponds to higher chlorophyll fluorescence in the middle and late stages of the culture. In addition, the bioproduct contained 39% carbohydrates, and the proportion of polyunsaturated fatty acids in lipids was 66%. These findings demonstrated that the over-compensation strategy contributed to greater nitrogen removal and high-value bioproduct production in the microalgae-digestate treatment system.
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Biotechnological production of omega-3 polyunsaturated fatty acids (PUFAs) has become a commercial alternative to fish oil in the past twenty years. Compared to PUFA production by fatty fishes, that from microorganisms has increased due to its promising sustainability and high product safety and to increasing awareness in the expanding vegan market. Although autotrophic production by microalgae seems to be more sustainable in the long term, to date most of the microbial production of omega-3 is carried out under heterotrophic conditions using conventional fermentation technologies. The present review critically analyzes the main reasons for this discrepancy and reports on the recent advances and the most promising approaches for its future development in the context of sustainability and circular economy.
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The MacroFuels project aims to advance the technologies for producing liquid transportation biofuels from cultivated seaweed (or macroalgae), thereby providing a sustainable solution for the provision of transportation fuels for heavy goods transport and the aviation sector.
Seaweeds are amongst the fastest growing plants in the world, producing large quantities of biomass over a short timespan. They do this without the use of fresh water, fertilizers, pesticides, and farmland, that are all needed for land-based cultivation. In order to grow, seaweed needs only carbon dioxide (CO2), sunlight and the nutrients already present in the ocean.
To validate the benefits of the seaweed biofuel concept and, ultimately, to provide a basis for the development of incentivising policies, a sustainability assessment is an integral part of the MacroFuels project. The assessment is a multi-criteria appraisal that evaluates the impacts of seaweed-derived transport fuels with respect to the environment and society and their technical and economic viability, as well as health, safety and risk aspects of the seaweed biofuel production system.
These different pillars of sustainability are assessed in individual work tasks. In order to facilitate the integrated sustainability assessment, to ensure consistency and to allow for consolidation and overall conclusions to be drawn, it is necessary that each work task is conducted on the basis of common criteria, where this is possible and appropriate. To this end, this report:
Defines the approach taken for the integrated sustainability assessment;
Presents the results of an integrated sustainability assessment of the MacroFuels concept; and
Provides options to improve the sustainability performance of the MacroFuels concept.
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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.