5 research outputs found

    In situ variability of carrageenan content and biomass in the cultivated red macroalga Kappaphycus alvarezii with an estimation of its carrageenan stock at the scale of the Malasoro Bay (Indonesia) using satellite image processing

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    International audienceThe combination of in situ measurements, hydrodynamical modeling, and satellite imagery processing presents a complete tool to improve seaweed culture management. This study measured the evolution of carrageenan content during 1-year period and estimated the biomass of Kappaphycus alvarezii at a bay scale in Malasoro Bay, Indonesia. It allowed the determination of the carrageenan stock at the scale of the bay. The carrageenan content was assessed from different parts, i.e., basal and apical, of the thallus. The biomass from T (0) (beginning of the cultivation) to T (45) (harvesting time) was determined at two seasons. Satellite image processing was performed to estimate the biomass at bay scale using parcels resulting from a semi-automatic delineation process. As no long-term in situ environmental data existed in the study area, a 3D hydrodynamical model (Model for Application at Regional Scale 3D) was implemented to obtain high-frequency salinity, water temperature, and currents. The high carrageenan yield was obtained from April to September 2015 (54-63%) when temperature ranged from 25 to 30 A degrees C, salinity range from 33.8 to 34.8 psu, and precipitation below 0.5 mm. The biomass at bay scale was estimated at 2590 t with the highest carrageenan stock at 1.8 t ha(-1) in May 2015. The carrageenan yields and quality obtained in this study fulfilled the specification recommended for industry, and the cultivation of K. alvarezii can be carried out at optimal environmental conditions on April-September. The comprehensive approaches used in this study provide information for carrageenan stock and seaweed culture management as an important economic activity to support Indonesian coastal communities

    Percentage cover, biomass, distribution, and potential habitat mapping of natural macroalgae, based on high-resolution satellite data and in situ monitoring, at Libukang Island, Malasoro Bay, Indonesia

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    WOS:000427804800018In this study, we combined remote sensing data and in situ observations to explore the potential habitats of macroalgae at Libukang Island, Indonesia. High-resolution satellite images from the GeoEye-1 were used to estimate and to map the geomorphological structures together with macroalgal species in the study area. Seasonal variations of percentage cover and biomass of macroalgae associated with substrates were investigated in May and November 2014, and June 2015, using quadrats as sampling unit. A total of nine common genera were found in the study area with three dominant genera: Sargassum, Padina, and Turbinaria. Most of macroalgae was observed in the eastern part of the Island, on several substrate types and particular oceanographic conditions (wave and current). Mean biomasses of Sargassum and Padina were high in May (1189.6 +/- 455 and 166.7 +/- 15.4 g DW.m(-2), respectively), while the biomass of Turbinaria was high in November (3245 +/- 599.8 g DW.m(-2)). The map accuracy of image classification for all typology substrates was 74.19%. Overall, approximately 62.3% of the total study area can be considered as potential for natural macroalgae habitats. Spectral response characteristic of shallow water substrates at study area based on GeoEye-1 is also presented. The results of this study exhibit a potential utilization of natural macroalgae in the study area, and provide information for a possible diversification of the use of macroalgae in Indonesia. The method could be useful for habitat management and future biomonitoring in the study area or other similar areas in Indonesia

    A comprehensive review of the brown macroalgal genus Turbinaria J.V. Lamouroux (Fucales, Sargassaceae)

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