Retraction of: Seaweed resources of Korea

Seaweed Resources in Europe: Uses and Potential, Edited by M.D. Guiry & G. Blunden. J. Wiley & Sons, Chichester, New York, Brisbane, Toronto, Singapore: xii + 432 pp., 121 illustrations, 51 tables, 23.5 × 15.5 × 2.4 cm, £53, 1992. - Volume 21 Issue 2

The plant species which were found along the sea – shore was called as “seaweed”. They were reported all along the Indian coastal state waters in variable amount. Among all these Indian coastal states Tamil nadu and Gujarat states contributes more seaweed resource. Seaweed were mainly found along the coastal waters of the ocean. According to colouration and pigmentation in plants they were classified in three categories; i.e. Red, Brown and Green seaweed. The various reports were reported that seaweed are utilized for many different purposes all along the world. They were mainly utilized for food, medicine, fertilizers etc. in this review article authors were discussed about the availability of seaweed resources along Indian waters and the mineral and proximate composition of commercially important seaweed species, which represents seaweed is one of the most important resource in future and so in future this scenario will ultimately causes the utilization and demand of seaweed was going on increasing, not only along Asian countries but also from all over the world. The Indian waters consideration represents, there was very less importance was given to seaweed as that of other oceanic resource, but in future India also going to give importance to seaweed mainly because over-fishing/ over-harvesting of other oceanic resources like fishes, shell fishes, mammals etc. from Indian oceanic waters. so all these thing together concluded that in future seaweed will became as one of the best alternative option for human beings.

Seaweeds are an integral part of coastal ecosystems and offer invaluable ecosystem services supporting the life of many marine forms. The economic value of seaweeds significantly contributes to the sustainable development of rural coastal regions. Seaweeds are consumed as food in some Asian countries, but their utilization for production of phycocolloids is widespread across the globe, with an estimated value of more than one billion US$. In India, seaweeds have been utilized exclusively for the production of phycocolloids but recently they are used for the production of plant growth stimulants for agricultural applications. The domestic agar and alginate industry totally depends on the supplies from natural seaweed beds with some occasional imports. The recent success achieved in both upstream and downstream technologies in production and processing of seaweeds has boosted the prospects for commercialization of seaweed resources in the country. The present article briefly appraises the current status of Indian seaweed resources and their utilization, as well as developments in seaweed farming technologies, the status of seaweed industry and recent efforts to transform seaweed farming into a social enterprise. It also highlights the challenges encountered for mainstreaming these resources so as to evolve into a marine industry.

The Maritime Spatial Planning Directive (2014/89/EU) required European Union member states to finalise Marine Spatial Plans by 2021. These efforts have created new forums for considering synergies and conflicts around blue growth objectives at both national and local scales, but in many cases have consolidated management action at European or national levels. These nationalised MSP actions can conflict with the path dependence (legacy effects) of traditional industries. The preparation and publication of Ireland's National Marine Planning Framework (NMPF) provides rich examples of how the legacy effects of traditional rights of access and withdrawal can both inform and complicate planning goals. This research describes these interactions in the context of Ireland's seaweed sector. Efforts to equitably expand and manage Ireland's seaweed resource are hampered by controversy in the licensing of seaweed harvesting. Interviews with seaweed harvesting stakeholders were analysed using modified grounded theory, supplemented with critical analyses of the NMPF. Interviews made clear a longstanding and successful path dependence of community management of the Ireland's seaweed resource. However, national blue growth targets may conflict with local management traditions, alienating goal dependence between institutions and actors. These conflicts are exacerbated by national and exclusionary definitions of seaweed ownership. This work reveals conflicts between top-down management and local traditions of seaweed harvesting and provides recommendations as to how Irish legislation could prevent actor alienation from the management process by considering path dependence in management decisions and cultivating interdependent relationships to ensure seaweed harvester rights are respected in management plans.

This study presents a comprehensive analysis of the morphological, phyto-physicochemical, and nutritional attributes of seaweed species found in the coastal waters of Cagayan, Philippines particularly in Barangay Sta Cruz, Gonzaga.Specifically six seaweeds were studied namely: Sea palm (Caulerpac taxifolia), Sea lettuce (Ulva lactuca linnaeus), Sea hair (Chaetamorpha crassa), Ar-arusip (Caulerpa lentillifera), Guraman (Gracilaria blodgetti ) and Lab-labig (Glacilaria tertorii) were used in the study.These Seaweeds play a pivotal role in marine ecosystems and offer substantial economic potential.However, detailed characterization of local seaweed species is essential for informed resource management and industrial applications.Phytochemical analysis was performed to determine the presence and quantity of bioactive compounds.Additionally, physicochemical properties such as pH, salinity, and nutrient content of the surrounding seawater were measured both on site and laboratory test to provide context for the observed seaweed characteristics.Furthermore, nutritional profiling was carried out using proximate analysis to ascertain the content of essential nutrients and dietary fiber in the selected seaweed species.Results indicated significant variations in the secondary metabolites and nutrient composition among species, highlighting their potential as valuable dietary supplements and functional food ingredients.Secondary metabolites found among the seaweeds include flavonoids and terpenoids among five species, saponins in four species, alkaloids in two species while anthocyanin is found only in Ar-arusip and phenol in Guraman.On the other hand, proximate analysis showed that among the three edible seaweeds Ararusip has the highest crude protein, crude fiber and crude fat compared with Guraman and Lab-labig.Also, the physico-chemical analysis of soil and water habitat of the seaweeds corresponds with the normal standard for marine waters.On-site and laboratory test of the physicochemical analysis of seaweed water provides valuable information about the environmental conditions that influence seaweed growth and health.This data is crucial for making informed decisions regarding seaweed resource management, conservation efforts, and sustainable utilization in various industries.This comprehensive study offers valuable insights into the diversity and potential applications of seaweed resources in Cagayan.The data generated will be invaluable for local stakeholders, including aquaculturists, conservationists, and industrialists, in making informed decisions regarding sustainable resource utilization and development.

Seaweed resources have received huge interest as a dietary source of proteins. In this study, we investigated the effects of process variables such assolvent-to-solid ratio, duration, temperature and pH on solubilisation of proteins from Enteromorpha compressa with the aim of developing a process of seaweed protein extraction. Protein solubilisation was also assessed for five additional seaweeds viz, the brown seaweed Turbinaria conoides, the red seaweeds Kappaphycus alvarezii, Gracilaria edulis, and Hypnea valentiae) and the green seaweed Halimeda gracilis, using the optimum conditions derived for E. compressa. Protein content in the dried seaweed samples ranged from 3.05-11.29%. Based on the extent of protein solubilisation, the optimal conditions were found to be a duration of 30 min, pH of 9, temperature of 90˚C and dried seaweed-to-solvent ratio of 1:30. Under these conditions, 19.90% of proteins from E. compressa were solubilised. Under the same process conditions, protein solubilisation from T. conoides, K. alverzii, H. gracilis, H. valentiae and G. edulis was 27.39, 30.88, 45.57, 19.68 and 40.32%, respectively. The investigation condluded thatprotein extraction from seaweeds is highly challenging and needs further research for improved recovery. Keywords: Alkali solubilisation, Process variables, Protein extraction, Seaweed protein

Seaweed cultivation (Kappaphycus alvarezii) is the primary source of livelihood for the coastal communities of Tanjung Village, Pamekasan, Madura. This study aims to examine the role of local wisdom in seaweed conservation, including traditional practices that support the coastal ecosystem. The research employed a qualitative approach using semi-structured interviews conducted with 15 key informants, including seaweed farmers, traditional leaders, and village officials. This was followed by a Focus Group Discussion (FGD) with 10 participants from seaweed farmer groups to confirm data and collectively discuss conservation and local wisdom issues. The collected data were analyzed using thematic analysis techniques to establish the relationship between traditional practices and the sustainability of seaweed. The study indicates that the local wisdom practiced by the Tanjung Village community, such as sasi rules (a traditional prohibition system) and traditional planting methods, contributes significantly to the conservation of Kappaphycus alvarezii seaweed. This local wisdom not only preserves the availability of seaweed resources but also strengthens social cohesion within the community. The integration of local wisdom with modern technology has the potential to enhance the effectiveness of conservation and seaweed productivity. Recommendations for advancing the cultivation of Kappaphycus alvarezii in Tanjung Village include: Collaboration between modern science and traditional practices is necessary to develop environmentally friendly and productive cultivation techniques, and the development of a community-based conservation model involving traditional leaders, farmers, and village officials is crucial for sustainable seaweed resource management.

Probing the coverage and biomass of seaweed is necessary for achieving the sustainable utilization of nearshore seaweed resources. Remote sensing can realize dynamic monitoring on a large scale and the spectral characteristics of objects are the basis of remote sensing applications. In this paper, we measured the spectral data of six dominant seaweed species in different dry and wet conditions from the intertidal zone of Gouqi Island: Ulva pertusa, Sargassum thunbergii, Chondrus ocellatus, Chondria crassiaulis Harv., Grateloupia filicina C. Ag., and Sargassum fusifarme. The different seaweed spectra were identified and analyzed using a combination of one-way analysis of variance (ANOVA), support vector machines (SVM), and a fusion model comprising extreme gradient boosting (XGBoost) and SVM. In total, 14 common spectral variables were used as input variables, and the input variables were filtered by one-way ANOVA. The samples were divided into a training set (266 samples) and a test set (116 samples) at a ratio of 3:1 for input into the SVM and fusion model. The results showed that when the input variables were the normalized difference vegetation index (NDVI), ratio vegetation index (RVI), Vre, Abe, Rg, Lre, Lg, and Lr and the model parameters were g = 1.30 and c = 2.85, the maximum discrimination rate of the six different wet and dry states of seaweed was 74.99%, and the highest accuracy was 93.94% when distinguishing between the different seaweed phyla (g = 6.85 and c = 2.55). The classification of the fusion model also shows similar results: The overall accuracy is 73.98%, and the mean score of the different seaweed phyla is 97.211%. In this study, the spectral data of intertidal seaweed with different dry and wet states were classified to provide technical support for the monitoring of coastal zones via remote sensing and seaweed resource statistics.

Seaweeds are an excellent source of unique antioxidant phytochemicals, dietary fibres, essential amino acids, vitamins, polyunsaturated fatty acids and minerals. The presence of such structurally diverse and high value bioactive compounds has led to popularization of seaweed as functional food ingredient in global health supplement market. India, with a long coastline of 8100km and exclusive economic zone of 2.17 million km2, is rich in diverse seaweed resources belonging to almost 700 species. However, food and nutraceutical application of Indian seaweed is highly constrained. Apart from Kappaphycus alvarezii, there is no systematic commercial cultivation of seaweed in India. The regulatory framework for use of seaweed as food is still developing and consumer acceptance is still low. However, there is a timely and renewed interest from different government agencies and research organisations to develop a thriving food and nutraceutical industry using India's vast seaweed resources. The review briefly describes the nutritional and functional food potential of the seaweed and goes on to discuss the scope of seaweed utilization in food and nutraceutical industry in India. Further, the review has identified the regulatory challenges and quality control requirements for use of seaweeds in food and nutraceuticals.

For the purpose of developing a useful seaweed resource, giant kelp (Macrocystis pyrifera) was introduced from Mexico into China in August–September, 1978. Since then, a series of studies has been made, including investigations on experimental ecology and techniques for cultivation and propagation of this species in natural beds. The present paper is an integrative and brief introduction to our recent work.

This study assessed the performance of widely used aquatic vegetation indices and introduced a novel index – the normalized difference aquatic vegetation enhancing index (NDAVEI). The NDAVEI was used to map seaweed resources in Pakistan along the 1,050 km long Karachi coast, and the results were compared with those obtained from other vegetation indices. Due to their widespread use in food, cosmetics and industrial goods, seaweed resources have great economic potential. They also play a significant role in aquaculture and fish breeding. Many sea species rely on seaweeds for their shelter and food requirements. The conservation of marine biodiversity needs seaweeds’ systematic monitoring and mapping to maintain the dependent species’ vital biological associations. Despite rich seaweed stock, these resources remain largely unmapped in Pakistan. Given these precious coastal resources’ significant economic and ecological importance, there is a pressing need to preserve and map seaweed sites in Pakistan. Traditionally, marine scientists have used sampling methods to describe shallow intertidal water marine habitats, but these methods are time intensive. Remote sensing (RS) data and geographical information system (GIS) tools are efficient and less time-consuming for mapping and classifying marine resources. This study compared the effectiveness of commonly used indices and NDAVEI to extract and map seaweed resources using high-resolution WorldView-2 satellite data. The results were verified through site observations. The NDAVEI can potentially improve the effectiveness and efficiency of seaweed mapping efforts. When combined with object-based image analysis (OBIA), it provides more precise area estimation than other indices.

The ecological effect of large-scale coastal natural and cultivated seaweed litter decay processes: An overview and perspective

Seaweed resources can be used as raw materials to produce bioethanol, a renewable biofuel, to overcome fossil fuel depletion and environmental problems. Red seaweeds possess high amount of bioethanol-producible carbohydrates. Among 55 species tested, the carrageenophyte Kappaphycus alvarezii (also known as cottonii) was selected as the best resource for bioethanol production. This species is one of the most abundant and easily cultured red seaweeds. The main components of carrageenan are d-galactose-4-sulfate and 3,6-anhydro-d-galactose-2-sulfate, which are potentially fermentable d-typed carbohydrates. The seaweed powder was hydrolyzed with 0.2 M sulfuric acid and fermented with brewer’s yeast. The ethanol yield from the K. alvarezii hydrolysate was 0.21 g g−1-galactose, which corresponded to a 41% theoretical yield. It revealed a relative ethanol production of 66% comparing to that of pure galactose.

Economically important red algae resources along the Chinese coast: History, status, and prospects for their utilization

Diversity and impacts of macroalgae and cyanobacteria on multi-stressed coral reefs in the Gulf of Mannar Marine Biosphere Reserve