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    • Types of Algae
    Author(s): John Benemann
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    Conventional off-shore and on-shore cultivation methods for marine macroalgae are both inadequate to pitch macroalgae as scalable renewable feedstock that can be grown across all coastal locations. With on-shore cultivation likely to be sustainable and preferred over eco-damaging open seas cultivation, new reactor systems need to be developed for on-shore cultivation of seaweeds at scale. The present work is an attempt to use the indigenously designed vertical multi-tubular air-lift photobioreactor system to grow Ulva lactuca through the entire year under natural conditions. Optimized operation of the 1000 L photobioreactor assembly demonstrated a year-round averaged productivity of 0.87 kg m−2.d−1 (fresh weight) implying 1800 ton.ha−1.y−1 feedstock production. Carbon dioxide supplementation (5%), optimized circulation velocity (0.25–0.35 m/s), and managing nitrogen supply (17 ppm), under natural light intensities (500–1400 μmol m−2.s−1) provided a year-round sustained and continuous production of Ulva lactuca biomass. The photobioreactor system designed as a modular, linearly scalable, and resilient system operates with low land and water footprints, and gives a multi-fold increase in renewable feedstock production compared to the conventional sea-based and other on-shore tank-based practices.

    For the video summary of this article, see the file in the supplemental data.

    Author(s): Prashant Savvashe, Akanksha Mhatre-Naik, Gayatri Pillai, Juilee Palkar, Mayur Sathe, Reena Pandita, C.R.K. Reddy, Arvind M. Lali
  • The Maine Seaweed Council (MSC) produces this “Harvester’s Field Guide to Maine Seaweeds” as a supplement to their “Harvest Guidelines for Maine Seaweeds.” The information in this Field Guide complements and supports the recommendations in the Guidelines. Using both documents, current and future harvesters will be able to make more informed choices about what, when, where and how they harvest – a crucial step towards sustainable harvesting in Maine, and the primary mission of the Maine Seaweed Council.

    Author(s):
  • In recent times, marine macroalgae (commonly known as seaweeds) drawing considerable attention globally as a renewable feed stock for various industrial applications. Commercial harvesting of seaweeds has reached new milestone with 27 million tones year-1 production (95% accounts to farming) with a market value of over US$ 4.8 billion (FAO, 2016). CSIR-Central Salt and Marine Chemicals Research Institute has been actively pursuing the seaweed research for nearly half a century. This institute takes pride in being first for pioneering seaweed cultivation, heralding an era of commercial seaweed farming in India. The production of Kappaphycus alvarezii has been substantially increased from 21 dry tonnes in 2001 to 1490 dry tonnes in 2013 with concomitant purchase value of < ₹ 4.5 to 35 ₹ kg−1 (dry). However, Indian seaweed industry is still depending on natural harvest for agrophytes specifically species of Gracilaria, Gelidium and Gelidiella. The continuous harvesting of natural stocks has been a growing concern for the long-term sustainability of the resource. In order to mitigate the over exploitation pressure on natural stocks, CSIR-CSMCRI developed sustainable cultivation methods of some of these species. Recently, Gracilaria dura from Indian waters has been reported to yield quality agarose as high as 20-25% on dry wt. basis with a gelling temperature 350C and gel strength of 1% gel > 1900 g. cm-2 this has attracted industrial attention. The fast expanding biotechnology and pharmaceutical sector in India is registering steady demand for agar, underpinning the need to initiate large scale farming of this alga. Thus successful aquaculture practise has been developed for ascertaining a continuous and reliable supply of quality raw material giving impetus to commercial operations especially in Gujarat coast – of which this alga is native. Among the hydrocolloids, agar is the second most prized product after agarose. According to a recent report, the wholesale price of agar has sharply increased to an all time high of USD 35-45 per kg due to scarcity of raw materials in response to resent regulations imposed by Moroccan government on natural harvest. The ongoing global supply chain crisis of agarophytes can be capitalized by India by spear heading the farming activity. This provides a scope and immense opportunity for India to emerge as a global producer as well as exporter of agarophytes. CSIR-CSMCRI in association with National Fisheries Development Board (NFDB), Hyderabad is trying to promote young fishermen as an entrepreneur from coastal villages across the country through successfully organizing trainings. The large-scale farming of this alga needs to be further strengthened and promoted by looking at potential socio-economic implication it offers for the inclusive economic growth in rural coastal settings. It would also help in the realization of the goal of doubling farmers' income by the year 2022. I sincerely believe that this manual will help new participants to practice seaweed cultivation more effectively. On behalf of CSIR and our Institute, I convey our best wishes for the successful implementation of the project.

    Author(s): Monica Kavale, V. Veeragurunathan, Vaibhav Mantri
  • We determined the feasibility of using salt-tolerant plants halophytes. as biofilters to remove nutrients from saline aquaculture wastewater. Suaeda esteroa, Salicornia bigeloii and Atriplex barclayana Chenopodiaceae., species with potential as forage and oil seed crops, were grown in sand in draining containers lysimeters. in a greenhouse experiment. They were irrigated to meet evapotranspiration demand and to produce a 0.3 leaching fraction, using aquaculture effluent generated from an intensive tilapia culture system. The effluent salinity was increased with NaCl to make salinity treatments of 0.5, 10 and 35 ppt. The plant–soil system removed 98% and 94% of the applied total and inorganic nitrogen, respectively. It removed 99% and 97% of the applied total and soluble reactive phosphorus, respectively. High removal rates occurred despite the high leaching fraction. Salt inhibited P - 0.05. the growth rate, nutrient removal, and volume of water that all three plant species could process. Suaeda and Salicornia, which are succulent salt marsh species, performed better than the desert saltbush, Atriplex, at the higher salinities.

    Author(s): J. Jed Brown, Edward P. Glenn, Kevin M. Fitzsimmons, Steven E. Smith
  • Aquaculture can have negative environmental impacts, adding to the suite of anthropogenic stressors that challenge coastal ecosystems. However, a growing body of scientific evidence indicates that the commercial cultivation of bivalve shellfish and seaweed can deliver valuable ecosystem goods and services, including provision of new habitats for fish and mobile invertebrate species. We completed a systematic literature review of studies focused on understanding habitat-related interactions associated with bivalve and seaweed aquaculture, and a brief meta-analysis of 65 studies to evaluate fish and mobile macroinvertebrate populations at farms and reference sites. Bivalve and seaweed aquaculture were associated with higher abundance (n = 59, range: 0.05× to 473×, median lnRR = 0.67) and species richness (n = 29, range: 0.68× to 4.3×, median lnRR = 0.13) of wild, mobile macrofauna. Suspended or elevated mussel and oyster culture yielded the largest increases in wild macrofaunal abundance and species richness. We describe the major mechanisms and pathways by which bivalve and seaweed aquaculture may positively influence the structure and function of faunal communities—including provision of structured habitat, provision of food resources and enhanced reproduction and recruitment—and identify the role of the species cultivated and cultivation gear in affecting habitat value. Given the continued deterioration of coastal habitats and increasing investments into their restoration, understanding how industry activities such as aquaculture can be designed to deliver food within ecological limits and have positive influences on ecosystem goods and services is essential in ensuring ecological, social and economic objectives can be achieved.

    Author(s): Robert C. Jones, Adam St. Gelais, Barry A. Costa- Pierce, Heidi K. Alleway, Luke T. Barrett, Seth J. Theuerkauf
  • To examine the effects of two endophytic algae, Mikrosyphar zosterae (brown alga) and Ulvella ramosa (green alga), on the host Chondrus ocellatus (red alga), culture experiments were conducted. Four treatments were made: endophytefree (Chondrus only), endophyte-M (Chondrus + Mikrosyphar), endophyte-U (Chondrus + Ulvella), and endophytes-M·U (Chondrus + Mikrosyphar + Ulvella). After 3 weeks, the relative growth rates (RGRs) of frond lengths and the number of newly formed bladelets were examined. M. zosterae formed wart-like dots on C. ocellatus fronds, whereas U. ramosa made dark spots. The RGRs of frond lengths of C. ocellatus were significantly greater in the endophyte-free and endophyte-M treatment groups than in the endophyte-U and endophytes-M·U treatment groups, indicating that the growth of host C.ocellatus was inhibited more by the green endophyte U. ramosa than the brown endophyte M. zosterae. The number of newly produced bladelets was greater in the endophyte-U and endophytes-M·U groups than in the endophyte-free and endophyte-M treatment groups. These results indicate that the two endophytes inhibit growth of the host C. ocellatus. The negative effects of U. ramosa on C. ocellatus growth were more severe than those caused by M. zosterae. Furthermore, U. ramosa destroyed the apical meristems of C. ocellatus, whereas M. zosterae did not. On the other hand, C. ocellatus showed compensatory growth in the form of lateral branch production as U. ramosa attacked its apical meristems.

    Author(s): Cyr Abel Maranguy Ogandaga, Han Gil Choi, Jang Kyun Kim, Ki Wan Nam
  • Aquaculture is an industry with the capacity for further growth that can sustainably feed an increasing human population. Sugar kelp (Saccharina latissima) is of particular interest for farmers as a fast-growing species that benefits ecosystems. However, as a new industry in the U.S., farmers interested in growing S. latissima lack data on growth dynamics. To address this gap, we calibrated a Dynamic Energy Budget (DEB) model to data from the literature and a 2-year growth experiment in Rhode Island (U.S.). Environmental variables forcing model dynamics included temperature, irradiance, dissolved inorganic carbon (DIC) concentration, and nitrate and ammonium concentration. The modeled final estimate for S. latissima blade length (cm) was reasonably accurate despite underestimation of early season growth. Carbon limited winter growth due to a low modeled specific relaxation rate (i.e. the light-dependent reactions of photosynthesis) for some model runs; other model runs displayed nitrogen limitation which occasionally led to length overestimation and underestimation due to the degree of interpolation necessary from the field data. The model usage, however, is restricted to S. latissima grown in an aquaculture setting because of assumptions made about tissue loss, summer growth patterns, and reproduction. The results indicate that our mechanistic model for S. latissima captures growth dynamics and blade length at the time of harvest, thus it could be used for spatial predictions of kelp aquaculture production across a range of environmental conditions. The model could be a particularly useful tool for further development of sustainable ocean food production systems in the U.S. involving seaweed.

    Author(s): CELESTE T. VENOLIA
  • The study was conducted at RTC-Korea-Philippines Vocational Training Center Davao, Buhisan, Tibungco, Davao City from March to May 2017 to determine the growth performance of carrots in terms of number of leaves and leaf stalks as supplied with different levels of Kappaphycus alvarezii drippings at 10 ml, 20 ml, and 30 ml per liter of water. Data were statistically analyzed through Randomized Complete Block Design (RCBD) with five (5) treatments replicated three (3) times. The treatments include pure water (T1), a nutrient solution of 10 ml of Kappaphycus alvarezii drippings per liter of water (T2), a 20 ml Kappaphycus alvarezii drippings per liter of water (T3), a 40 ml Kappaphycus alvarezii drippings per liter of water (T4), and a concentration of water and commercial organic foliar fertilizer (T5). Results showed that the application of Kappaphycus alvarezii drippings through subsurface drip irrigation improved the vegetative growth of carrot in terms of the leaf stalk and leaf count at 30, 37, and 45 days after sowing, under greenhouse structure.

    Author(s): Carlo R. Guinita
  • Palmaria palmata was integrated with Atlantic halibut Hippoglossus hippoglossus on a commercial farm for one year starting in November, with a temperature range of 0.4 to 19.1°C. The seaweed was grown in nine plastic mesh cages (each 1.25 m3 volume) suspended in a concrete sump tank (46 m3) in each of three recirculating systems. Two tanks received effluent water from tanks stocked with halibut, and the third received ambient seawater serving as a control. Thalli were tumbled by continuous aeration, and held under a constant photoperiod of 16 : 8 (L : D). Palmaria stocking density was 2.95 kg m-3 initially, increasing to 9.85 kg m-3 after a year. Specific growth rate was highest from April to June (8.0 to 9.0°C),1.1% d-1 in the halibut effluent and 0.8% d-1 in the control, but declined to zero or less than zero above 14°C. Total tissue nitrogen of Palmaria in effluent water was 4.2 to 4.4% DW from January to October, whereas tissue N in the control system declined to 3.0-3.6% DW from April to October. Tissue carbon was independent of seawater source at 39.9% DW. Estimated tank space required by Palmaria for 50% removal of the nitrogen excreted by 100 t of halibut during winter is about 29,000 to 38,000 m2, ten times the area required for halibut culture. Fifty percent removal of carbon from the same system requires 7,200 to 9,800 m2 cultivation area. Integration of P. palmata with Atlantic halibut is feasible below 10°C, but is impractical during summer months due to disintegration of thalli associated with reproductive maturation.

    Author(s): Peter Corey, Jim Duston, David J. Garbary, Jang K. Kim

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