The northern Gulf of Mexico (GOM) is well known for hypoxic water conditions (O2≤2 mg L1), and is often referred to as the “Dead Zone”. The area of the Dead Zone has increased remarkably during the recent decades due to the increased coastal eutrophication. Under such conditions, denitrification process that removes “available nitrogen” from the system would likely become more active, and it needs to be better quantified to understand the nature of biogeochemical nitrogen cycles in the northern GOM. Despite its significance, few denitrification studies have been conducted for this area. We estimate the temporal variation of denitrification rates of the bottom waters at the northern Gulf of Mexico encompassing the “Dead Zone” during July of the 1985–2007 period (except for 1988–1990). We use historic hydrographic data and the extended Optimum Multi-Parameter analysis. Denitrification rates of the bottom waters in the region have gradually decreased from 1985 to 1997, and then increased to 2007. The water mass mixing composition of bottom waters on the Texas–Louisiana inner shelf has changed since ∼1997. The Texas–Louisiana Coastal Water part has increased and that of the Subtropical Underwater has decreased. This change appears to have influenced the denitrification rates in the study area. We suggest that denitrification rates of bottom waters in the northern Gulf of Mexico are controlled not only by biogeochemical factors (i.e. organic matter supply and remineralization), but also by physical factor (i.e. stratification and relative contributions from different water masses).
Digital library
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The purpose of this Standard is to provide uniform terminology and definitions in the general area of biomass production and utilization. This includes all the terminologies that are used in biomass feedstock production, harvesting, collecting, handling, storage, pre-processing and conversion, bioenergy, biofuels, biopower and biobased products.
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Sea purslane Halimione portulacoides (L.) Aellen is a candidate extractive species for coastal Integrated Multi-Trophic Aquaculture (IMTA) to recycle the dissolved inorganic nitrogen (DIN) and phosphorus (DIP) wasted by excretive species. To test its suitability, saline aquaculture effluents were simulated in the laboratory using a hydroponics approach to cultivate the plants. Nutrient extraction efficiency, growth performance and nutritional profile were assessed under a range of DIN and DIP concentrations representing three different aquaculture intensification regimes and using Hoagland's solution as a control. Over a 10-week period, hydroponic units under non-limited N and P conditions displayed daily extraction rates between 1.5 and 2.8 mg DIN-N L-1 day-1 and 0.1-0.2 mg DIP-P L-1 day-1 and yielded between 63.0 and 73.0 g m-2 day-1 of H. portulacoides biomass. Relatively to biomass produced, H. portulacoides extracted between 2.6 and 4.2 mg DIN-N g-1 and 0.1-0.4 mg DIP-P g-1. The treatment with low-input of DIN and DIP (6.4 mg N L-1 and 0.7 mg P L-1) induced some degree of nutrient limitation, as suggested by the extremely high extraction efficiencies of DIN extraction (99%) in parallel with lower productivity. The nutritional profile of H. portulacoides leaves is comparable to that of other edible halophytes and leafy greens and could be a low-sodium alternative to salt in its lyophilized form. From the present study, we conclude that the edible halophyte H. portulacoides can be highly productive in hydroponics using saline water irrigation with non-limiting concentrations of DIN and DIP and is, therefore, a suitable extractive species for coastal IMTA in brackish waters.
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The 21st International Seaweed Symposium (ISS) took place in Bali, Indonesia, from April 21 to 26, 2013. For more than six decades, the ISS have been the foremost international symposia for individuals and organizations involved with seaweed research and applications. Over the years, ISS have provided a renewed forum for scientists, technologists, business people and resource managers to present their latest research results, exchange ideas and network to develop synergies for strengthening this important bioresource sector. This year was no exception, as 580 participants from 50 countries, and 33 exhibitors from six countries, presented and discussed many aspects focusing on the theme of this year’s edition “Seaweed Science for Sustainable Prosperity”. This theme recognized the fact that scientific research plays a fundamental role in the development of seaweed cultivation, harvesting, processing and commercialization, as well as in the well-being of many coastal communities. The 21st ISS was held in Bali, in the heart of the Coral Triangle where seaweed farming employs tens of thousands of coastal people. There is a clear and present need for expanding research and development to enable environmentally, economically and societally sustainable seaweed industry commercialization, not only in the Coral Triangle but also in other regions throughout the world, either alone or integrated with other aquaculture activities. One of the goals of the 21st ISS was to catalyze support for such endeavours.
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The 23rd International Seaweed Symposium (ISS) was held in Jeju, Republic of Korea, on April 28 to May 3, 2019, at the International Convention Centre. The ISS is a triannual congress held under the auspices of the International Seaweed Association (ISA; www.ISASeaweed.org). Starting from humble beginnings in 1952 with the First International Seaweed Symposium in Edinburgh, Scotland, with Dr. F.N. Woodward as chairman (Indergaard 2017), we are now almost 7 decades further with the 23rd Symposium in Korea. In 1952, almost 200 people attended from 21 different countries, and 53 papers were submitted; we now have peaked at over 850 registrants from 41 different countries, 22 mini symposia, 349 oral presentations, and 259 poster presentations (Fig. 1). During the last decade, seaweeds in general have become very popular as they have such a wide and diverse application from raw material and aquaculture/IMTA to fertiliser and biostimulants, feed and animal health, food and human health to materials, fabric, pharma, biotechnology and carbon sequestration/ habitat restauration (Fig. 2). Coupling this to the Korea’s long history and tradition of seaweed aquaculture and food use and the 23rd ISS was guaranteed to become a success. We are also happy to report that the exhibition/trade show is a growing part of the ISS which became very apparent at the Korean congress demonstrating the wide variety of seaweed use in everyday life. The link with the seaweed industry is of vital importance to the ISS concept and stimulates synergy and partnerships between academics and industry and provides vital important funding to be able to run these conferences.
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At Eastern Fish Company, we know that maintaining a healthy aquatic environment is the
basis of a healthy food supply. We support a wide range of efforts aimed at keeping our
oceans thriving while finding better ways to manage and harvest the bounty of our seas.
Now more than ever, it is important to choose your suppliers and marketing partners
based on their commitment not just to our industry, but to the environment as well.
We partner with suppliers that implement and maintain BAP standards to assure industry
stewardship. Where BAP standards do not apply, we work to source our product from only
well managed or certified fisheries. -
Macroalgae commonly found in the ocean around Hawaii were collected from near shore locations and their potential as biomass feedstock for fermentative ethanol was investigated. A green alga, Ulva reticulata, was selected for further analysis. This species forms large complex structures that grow quickly and has high dry biomass percentage (20%), soluble carbohydrates (18%); and high total carbohydrates along with low quantities of lignin (13%). During acid saccharification, it was determined that 49% of the total mass was observed as sugars in the hydrolysate; however, fermentation was problematic. Enzymatic saccharification using cellulase from Trichoderma reesei was attempted which recovered a measured maximum of 20% glucose based on the initial dry mass. Fermentation successfully converted all the glucose to ethanol. The measured ethanol yield corresponded to approximately 90 L per tonne of dried macroalgae.
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Introduced species may outcompete or hybridize with native species, resulting in the loss of native biodiversity or even alteration of ecosystem processes. In this study, we reported an alien distromatic Ulva species, which was found in an embayment (Holly Pond) connected with Long Island Sound, USA. The morphological and anatomical observations in combination with molecular data were used for its identification to species. Anatomy of collected specimens showed that the cell shape in rhizoidal and basal regions was round and the marginal teeth along the basal and median region were not found. These characteristics were primarily identical to the diagnostic characteristics of Ulva laetevirens Areschoug (Chlorophyta). The plastid-encoding tufA and nucleusencoding ITS1 were used for its molecular identification. Phylogenetic analysis for the tufA gene placed the specimens from Holly Pond in a well-supported clade along with published sequences of U. laetevirens identified early without any sequence divergence. In ITS tree, the sample also formed well-supported clades with the sequences of U. laetevirens with an estimated sequence divergence among the taxa in these clades as low as 1%. These findings confirmed the morpho-anatomical conclusion. Native to Australia, this species was reported in several countries along the Mediterranean coast after the late of 1990s. This is the first time that U. laetevirens is found in the northeast coast of United States and the second record for Atlantic North America.
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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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Apart from being applied as a source of human food, animal feed, fertilizers, components of cosmetics, pharmaceuticals and nutraceuticals, biofuels, fast-growing seaweeds can also be used to prevent environmental pollution, for bioremediation of polluted environment and in environmental biomonitoring (bioindication of marine ecosystem pollution). They are known to effectively remove toxic metals (e.g., arsenic, cadmium, chromium, cobalt, copper, lead, mercury, nickel, zinc) and organic compounds (e.g., DDT, PCB) from contaminated soil, industrial effluents and wastewater treatment. Biosorption of toxic metal ions by dry seaweeds is a kind of biotreatment of polluted water. Also the bioremediation of nutrients, generated by intensive aquaculture (e.g., fish, shrimps and other aquatic animals) in so-called integrated multitrophic aquaculture makes use of seaweeds. Macroalgae derived from unpolluted water – e.g., eutrophicated natural water reservoirs or remediated wastewater from aquaculture can be used for the production of components of fertilizers, feed additives and biochar which provides a multitude of benefits in terms of environmental management, e.g., climate change mitigation due to carbon sequestration, remediation of contaminated sites (water, soil) due to very good sorption properties, plus the mitigation of contaminants movement in soil due to action as a landfill filter medium. The proposed biotechnological tools based on seaweeds biomass can improve the environment and assure its sustainability.
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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.