Seaweed Production Research Articles

Understanding and estimating the role of large-scale seaweed cultivation for carbon sequestration on a global scale over the past two decades

Seaweeds, as marine photosynthetic organisms, are harvested by humans from the wild or through cultivation for various production purposes and to provide a range of marine ecosystem services, including nutrient removal, oxygen production, and carbon sequestration. The potential use of cultivated seaweed in mitigating carbon dioxide (CO2) has been extensively proposed in conjunction with commercial seaweed production worldwide. This study aims to assess the annual potential and benefits of cultivated seaweed in reducing and fixing anthropogenic CO2. Over the past two decades (2000–2019), global seaweed production has seen significant growth. The total output of cultivated seaweed reached 407.4 × 107 tons (t), with coastal mariculture removing 4.26 × 107 t of carbon annually and wild capture removing 2.24 × 106 t. The recalcitrant dissolved organic carbon (RDOC, 549.88–621.60 × 104 t) plays a significant role in the carbon sinks of seaweed cultivation. The substantial benefits of carbon sink resulting from the formation of RDOC from seaweed make up a considerable proportion in the calculation of carbon sequestration and sink enhancement benefits in large-scale seaweed cultivation. The sizable carbon sink base of seaweed cultivation (8631.90–9567.37 × 104 t) results in significant carbon fixation benefits. The total economic value of carbon sequestration and oxygen production was estimated at $70.36 ± 1.52 billion, with an annual average benefit of $3.52 ± 1.70 billion. Increasing the area and yield available for cultivated seaweed has the potential to enhance biomass production, carbon accumulation, and CO2 drawdown. It is crucial to emphasize the need for improved communication regarding the essential criteria for the feasibility of CO2 removal (CDR), with a focus on conducting life cycle assessments (LCA) when utilizing marine processes in the present and future work. The sustainable development of the seaweed cultivation industry not only ensures that Asian-Pacific countries remain leaders in this field but also provides an effective yet overlooked solution to excessive CO2 emissions worldwide.

A Computer Vision Model for Seaweed Foreign Object Detection Using Deep Learning

Seaweed foreign object detection has become crucial for food consumption and industrial use. This process not only can prevent potential health issues, but also maintain the overall marketability of seaweed production in the food industry. Traditional methods of inspecting seaweed foreign objects heavily rely on human judgment, which deals with large volumes with diverse impurities and can be inconsistent and inefficient. An automation system for real-time seaweed foreign object detection in the inspection process should be adopted. However, automated seaweed foreign object detection has several challenges due to its dependency on visual input inspection, such as an uneven surface and undistinguishable impurities. In fact, limited access to advanced technologies and high-cost equipment would also influence visual input acquisition, thereby hindering the advancement of seaweed foreign object detection in this field. Therefore, we introduce a computer vision model utilizing a deep learning-based algorithm to detect seaweed impurities and classify the samples into ‘clean’ and ‘unclean’ categories. In this study, we managed to identify six types of seaweed impurities including sand sticks, shells, discolored seaweed, grass, worm shells, and mixed impurities. We collected 1204 images and our model’s performance was thoroughly evaluated based on comparisons with three pre-trained models, i.e., Yolov8, ResNet, and MobileNet. Our experiment shows that Yolov8 outperforms the other two models with an accuracy of 98.86%. This study also included the development of an Android application to validate the deep learning engine to ensure its optimal performance. Based on our experiments, the mobile application managed to classify 50 pieces of seaweed samples within 0.2 s each, showcasing its potential use in large-scale production lines and factories. This research demonstrates the impact of Artificial Intelligence on food safety by offering a scalable and efficient solution that can be deployed in other food production processes facing similar challenges. Our approach paves the way for broader industry adoption and advancements in automated foreign object detection systems by optimizing detection accuracy and speed.

Toxicity of the marine glycosidic macrolides, polycavernoside E and akunolides, from Okinawan cyanobacterium Okeania sp. in mice

The toxicity of polycavernoside E and its structurally related macrolides, akunolides A, B, and C, was evaluated in mice. These compounds were recently isolated from the marine cyanobacterium Okeania sp. collected in Okinawa, Japan. The minimal toxicity of polycavernoside E was estimated as 0.81 mg/kg by intraperitoneal injection, whereas those of akunolides A–C were >13 mg/kg. Owing to the considerable toxicity of polycavernoside E, the occurrence of this cyanobacterium should be considered in seaweed production environments.

Seaweed sinking has great potential for climate mitigation in China

With the intensification of the greenhouse effect, the climate-mitigation role of marine carbon sequestration (blue carbon) is gaining more attention. Seaweed aquaculture, as an important nature-based solution that provides various ecosystem services while as a food source, have become the main way of marine biological carbon sequestration. As an emerging carbon dioxide removal strategy, sinking seaweeds to the deep sea for additional CO2 sequestration to contribute to Paris Agreement temperature goal have attracted much attention. Currently, the ecological value assessment of sinking seaweeds is immature, and there is also a conflict between with traditional food values. However, in the long term, the value of carbon sequestration will continuously rise as global emission reduction advance, and rapidly growing seaweed production will be able to fully satisfy food demand in the future. Therefore, sinking surplus seaweeds to convert excess food value into higher ecological value is more compatible with development prospects, and long-term planning for sinking seaweed is particularly important. As the largest seaweed farming country, China accounted for more than half of the world’s production in 2021, possessing a huge potential for carbon sequestration. Incorporating factors such as food requirements, emission reduction demands and population changes, this paper explored the feasibility and planning of sinking seaweeds to serve the achievement of climate goals under five SSP-RCP scenarios in 2020–2050. The results indicate that with the slowdown in population growth and increasing demand for climate mitigation, the ecological value of seaweeds has more development potential than the edible value, and thus the sunken seaweed task should be placed more in the later period (2041–2050 phase) to maximize the ecological benefits of seaweed farming. Sinking seaweed is able to serve the SSP1-2.6 and SSP2-4.5 scenarios relatively well, while the realization of the SSP1-1.9 scenario presents some challenges.

Thermal priming of Saccharina latissima: a promising strategy to improve seaweed production and restoration in future climates

Saccharina latissima is a brown algal kelp species of ecological and economic importance. As the rise in sea surface temperature will threaten not only wild populations of S. latissima but also the productivity of kelp farms, crop enhancement techniques will become crucial to mitigate this threat. Priming is a common strategy in crop plants, in which seeds are pre-exposed to moderate stress to improve the performance and tolerance of plants when exposed to harsher conditions. We investigated the potential of thermal priming to improve growth and tolerance of S. latissima. Kelp gametophytes primed at 20°C for 2, 4 and 6 wk and then re-transferred to 5°C were compared to a naïve treatment maintained at 5°C. Gametophyte priming increased growth of subsequently formed sporophytes by up to 30% (for 4 wk priming) compared to the naïve treatment. Female gametophyte growth in the priming environment was positively correlated to offspring sporophyte growth, indicating a maternal effect. Sporophytes were exposed to heat stress of 20°, 22°, 23° and 24°C for 2 wk. Sporophytes from 4 and 6 wk primed gametophytes exhibited 11 d longer tolerance at 22°C, 7 d longer tolerance at 23°C and 1°C higher thermal tolerance over 7 d compared to naïve sporophytes and sporophytes from 2 wk priming. A priming time of 4 wk was optimal for both sporophyte growth and thermal tolerance. Our results suggest that priming is a promising crop enhancement technique that could improve yield for seaweed farmers and restoration of kelp forests threatened by warming climates.

Winners and losers in US marine aquaculture under climate change

Abstract Mariculture will be important to meeting global seafood food demand in the coming decades. Yet, the threat of climate change—such as rising ocean temperatures—on mariculture performance remains uncertain. This is particularly true at small spatial scales relevant to most producers. Additionally, mariculture is often limited by regulations that impose restrictions on production, creating potential hurdles for anticipating and adapting to climate change. We focus on mariculture performance in the United States (U.S.), where state and federal policies and exposure to climate change vary substantially and likely interact. We map a current and future mariculture performance index by combining the first high resolution downscaled (0.083°) climate outputs for U.S. waters, species-specific physiological requirements, and policy restrictions. We find high current performance that will increase under warming oceans, with spatial variation that will amplify existing regional differences. Generally, performance will increase in the north and decrease in the south. While the permitting process is not intentionally climate-forward, permitted species outperformed taxon averages, yet state policies often limit production of seaweeds and finfishes, which perform well. Thus, we sit at a critical juncture where the U.S. could capitalize on its seemingly favorable environmental conditions through re-alignment of regulations to support portfolio diversification to include climate-resilient species.

Light Spectra, a Promising Tool to Modulate Ulva lacinulata Productivity and Composition.

Light quality is a key factor affecting algal growth and biomass composition, particularly pigments such as carotenoids, known for their antioxidant properties. Light-emitting diodes (LEDs) are becoming a cost-effective solution for indoor seaweed production when compared to fluorescent bulbs, allowing full control of the light spectra. However, knowledge of its effects on Ulva biomass production is still scarce. In this study, we investigated the effects of LEDs on the phenotype of an Ulva lacinulata strain, collected on the Northern Portuguese coast. Effects of white (W), green (G), red (R), and blue (B) LEDs were evaluated for growth (fresh weight and area), photosynthetic activity, sporulation, and content of pigments and antioxidant compounds. The results showed that there were no significant differences in terms of fresh weight accumulation and reduced sporulation among the tested LEDs, while W light induced the highest expansion rate. Under G, U. lacinulata attained a quicker photoacclimation, and the highest content of pigments and total antioxidant activity; but with R and W, antioxidant compounds against the specific radicals O2•- and •NO were produced in a higher content when compared to other LEDs. Altogether, this study demonstrated that it is possible to modulate the bioactive properties of U. lacinulata by using W, R, and G light, opening the path to the production of biomass tailored for specific nutraceutical applications.

Research-Based Policy Brief for Enhancing the Seaweed Production in the Selected Municipalities of Tawi-Tawi

Research-Based Policy Brief for Enhancing the Seaweed Production in the Selected Municipalities of Tawi-Tawi

Evaluating the Effectiveness of Seaweed Production Policies in Tawi-Tawi: A Foundation for Designing a Policy Determination Model

Seaweed farming is a vital economic activity in coastal regions, offering potential for sustainable development and poverty alleviation. In the Philippines, particularly in Tawi-Tawi, seaweed production supports local livelihoods and regional economic growth. Despite its importance, the effectiveness of seaweed production policies in Tawi-Tawi is underexplored. This study identifies critical gaps in these policies, evaluates their effectiveness and implementation, and proposes evidence-based recommendations to enhance sustainability and productivity. Using a mixed-methods approach, the research integrates quantitative data from field surveys and qualitative insights from stakeholder interviews. Findings indicate that the overall level of policy implementation in Tawi-Tawi's seaweed production is slight, with an overall effectiveness mean score of 2.51 (slightly effective). The effectiveness in specific areas includes the local economy (2.71), tourism (2.50), stakeholders (2.44), political (2.52), environment (2.34), and laws (2.55). The correlation coefficient of 0.637 indicates a strong positive relationship between Implementation Perception and Implementation Impact/Efficiency, highlighting the need for improved policy measures. Effective seaweed production policies in Tawi-Tawi are crucial for local economic growth but currently show only slight implementation and effectiveness. Addressing gaps and enhancing collaboration can significantly improve outcomes for the industry and community.

Social Capital in the Patron-Client Dimension towards the Sustainability of Seaweed Cultivation Businesses in Rural Areas, South Sulawesi, Indonesia

The system of livelihoods in seaweed cultivation becomes the subject of study because of the factor of production, and the distribution of the output of production requires a strategy of merging between something material and non-material that involves interaction with various actors in society. The social capital awakened by the actors in the seaweed cultivation business through the patron-client dimension is an effort to ensure the sustainability of the business. The study aims to characterize the components of social capital that bind, bridge, and connect in the context of the relationship between actors in seaweed cultivation, including the important role of the combination of these three types of social capital in the sustainability of the seaweed cultivation business. The Research methods use qualitative descriptive approaches. Data is collected through semi-structured interviews and analyzed with open, axial, and selective encoding. The results show that actors in seaweed cultivation enterprises combine the social capital components of bonding, bridging, and linking selectively, depending on the interests behind each interaction with different actors. Social bonding capital is owned by seaweed farmers in their interactions to gain access to financial capital (in the form of cash and loans). The patron-client relationship pattern is the most prominent of the reciprocity relationships, where the patron is the provider of corporate capital and the guarantor of subsistence is the cultivator. The social bridging and linking capital is owned in its interaction to gain access to social assistance and political support as well as networking. Mechanisms of sale of seaweed production are dominated by marketing networks using intermediary services (middlemen) through the concept of personalized exchange. In such market trading, the symptoms of “boro” (guarantees) are detected through subscription relationships between sellers and buyers characterized by regular personality contacts and through credit mechanisms known as “take now, pay later”. Therefore, social capital plays an important role in the sustainability of seaweed farming in the countryside. In a situation of economic or environmental change, social capital can help the farmer adapt and survive in his business and household life. We found that social capital plays an important role in the rural habitat system, where access to livelihoods depends on social relationships. Thus, support is needed to strengthen the capacity of social capital in societies because the configuration of the social capital elements can inherit the cognitive social capital, the social structural capital and the social relational capital necessary for the improved social, economic and cultural development of societies.

Factors Affecting Seaweed (Eucheuma cottoni) Production in Banten Province (Case in Lontar Village)

Seaweed is one of the plants that has a lot of potential as a functional food ingredient, active ingredient of drug preparation and even cosmetics that are quite natural in producing various pharmacological activities both as a source of antioxidants, antibacterials, antimicrobials and anticancer. Seaweed is currently a potential asset for areas that are able to produce it to meet the increasing market needs. Lontar Village, located in Banten Province, is one of the main seed producing areas. However, seed production factors are one of the main indicators that need to be used as a standard in this study, such as the length of the rope span, age characteristics, education characteristics, characteristics of the seed farmer's business experience. This type of research is quantitative and data is obtained primarily and secondarily. The data obtained were analyzed using the SPSS 26 program. The results of the study showed that the factors that influence seaweed production in Banten Province, especially Lontar Village, are influenced by the length of the rope span, age characteristics, education characteristics, characteristics of the seaweed farmer's business experience. The conclusion is that seaweed production is influenced by various characteristics, namely age, education, and seaweed farming experience.

The effects of kelp powder and fucoidan on the intestinal digestive capacity, immune response, and bacterial community structure composition of large yellow croakers (Larimichthys crocea)

Feed terrestrial components can induce intestinal stress in fish, affecting their overall health and growth. Recent studies suggest that seaweed products may improve fish intestinal health. In this experiment, three types of feed were prepared: a basic diet (C group), a diet with 0.2 % fucoidan (F group), and a diet with 3 % kelp powder (K group). These diets were fed to large yellow croaker (Larimichthys crocea) over an 8-week period. Each feed was randomly assigned to three seawater cages (4.0 m × 4.0 m × 5.0 m) containing 700 fish per cage. The study assessed changes in growth and intestinal health, including intestinal tissue morphology, digestive enzyme activities, expression of immune-related genes, and bacterial community structure. Results showed that incorporating seaweed products into the diet improved the growth and quality traits of large yellow croakers and significantly enhanced their intestinal digestive capacity (P < 0.05). Specifically, the 0.2 % fucoidan diet significantly increased the intestinal villus length and the activities of digestive enzymes such as trypsin, lipase, and α-amylase (P < 0.05). The 3 % kelp powder diet significantly enhanced the intestinal crypt depth and the activities of trypsin and lipase (P < 0.05). Both seaweed additives significantly enhanced intestinal health by mitigating inflammatory factors. Notably, the control group's biomarkers indicated a high presence of potential pathogenic bacteria, such as Streptococcus, Pseudomonas, Enterococcus, Herbaspirillum, Neisseria, Haemophilus, and Stenotrophomonas. After the addition of seaweed additives, these bacteria were no longer the indicator bacteria, while the abundance of beneficial bacteria like Ligilactobacillus and Lactobacillus increased. Significant reductions in the expression of inflammatory factors (e.g., il-6, tnf-α, ifn-γ in the fucoidan group and il-8 in the kelp powder group) further supported these findings. Our findings suggested that both seaweed additives helped balance intestinal microbial communities and reduce bacterial antigen load. Considering the effects, costs, manufacturing, and nutrition, adding 3 % kelp powder to the feed of large yellow croaker might be preferable. This study substantiated the beneficial effects of seaweed on the aquaculture of large yellow croaker, particularly in improving intestinal health. These findings advocated for its wider and more scientifically validated use in fish farming practices.

Ice-Ice Disease Prevalence and Intensity in Eucheumatoid Seaweed Farms: Seasonal Variability and Relationship with the Physicochemical and Meteorological Parameters.

Since its initial report in the Philippines in 1981, ice-ice disease (IID) remains a substantial threat to the sustainability of eucheumatoid seaweed production. However, comprehensive investigations into the prevalence, intensity, and potential relationships with physicochemical and meteorological parameters are limited, particularly in open-sea farms. This is the first study to conduct a 12-month monitoring of IID prevalence and intensity in eucheumatoid seaweed farms in Tawi-Tawi, Philippines. The research aimed to elucidate seasonal variations and potential associations with physicochemical and meteorological parameters. The findings revealed significant seasonal variations in IID prevalence, with a higher incidence observed during the dry season compared to the wet season. Additionally, deep-water farms exhibited significantly higher prevalence and ice-ice spot numbers per bundle compared to shallow-water farms. Furthermore, Kappaphycus striatus displayed a significantly greater ice-ice spot length per bundle compared to K. alvarezii. Notably, no interaction effects were observed among season, species, and depth. Interestingly, while no correlations were found between ice-ice disease and most measured physicochemical and meteorological parameters (temperature, salinity, pH, water current velocity, wind speed) or nutrient concentrations (phosphate, nitrate, nitrite), an inverse correlation (p < 0.05) emerged between ammonium levels and IID intensity parameters (number and length of ice-ice spot per bundle). Moreover, a positive correlation was observed between monthly rainfall and IID intensity. These findings offer valuable insights into the dynamics of IID in open-sea eucheumatoid seaweed (Kappaphycus) farming, highlighting the influence of seasonality, depth, and species susceptibility, as well as the relationship between IID severity and ammonium levels and rainfall.

Safety assurance and nutritional quality enhancement of Phyllospora comosa biomass using hydrothermal treatment derived ensemble machine learning models

One of the major barriers to the mass industrial utilisation of brown seaweeds as food sources stem from the food safety risks associated with their iodine and arsenic concentrations, which typically exceed regulatory limits. Hydrothermal treatments might effectively reduce the high iodine and arsenic concentration of Phyllospora comosa below the Australian maximum residual limits (iodine = 1 mg/g and arsenic = 0.00667 mg/g; dry weight) set for brown seaweeds. The experimental hydrothermal treatments dictated that the 82 °C–250 s treatment reduced the iodine concentration from 2.76 mg/g to 0.88 mg/g (68% reduction) and arsenic concentration from 0.01693 mg/g to 0.00965 mg/g (43% reduction). Machine learning models predicted that blanching at 100 °C for ∼4 minutes will reduce the arsenic concentration below its maximum residual limit. Additive log-ratio transformations showed that around 50% (dw) of the hydrothermally treated Phyllospora comosa samples were leached out during the highest treatment intensity, 82 °C–250 s. Even though, a half of the biomass is lost, hydrothermally treated Phyllospora comosa products are safer for human consumption and thus may permit the expansion of seaweed production and consumption in Australia.

Sustainable high-quality seaweed production from deep seawater

Sustainable high-quality seaweed production from deep seawater

The potential climate benefits of seaweed farming in temperate waters

Seaweed farming is widely promoted as an approach to mitigating climate change despite limited data on carbon removal pathways and uncertainty around benefits and risks at operational scales. We explored the feasibility of climate change mitigation from seaweed farming by constructing five scenarios spanning a range of industry development in coastal British Columbia, Canada, a temperate region identified as highly suitable for seaweed farming. Depending on growth rates and the fate of farmed seaweed, our scenarios sequestered or avoided between 0.20 and 8.2 Tg CO2e year−1, equivalent to 0.3% and 13% of annual greenhouse gas emissions in BC, respectively. Realisation of climate benefits required seaweed-based products to replace existing, more emissions-intensive products, as marine sequestration was relatively inefficient. Such products were also key to reducing the monetary cost of climate benefits, with product values exceeding production costs in only one of the scenarios we examined. However, model estimates have large uncertainties dominated by seaweed production and emissions avoided, making these key priorities for future research. Our results show that seaweed farming could make an economically feasible contribute to Canada’s climate goals if markets for value-added seaweed based products are developed. Moreover, our model demonstrates the possibility for farmers, regulators, and researchers to accurately quantify the climate benefits of seaweed farming in their regional contexts.

Anti-inflammatory and analgesic activities of the ethanolic extract of Seaweed Asparagopsis spp. Isolated from the Bay of Bengal, Bangladesh

The marine zone of Bangladesh covers a great diversity of natural ecosystems including a marine environment rich in commercially important seaweeds. Seaweeds are widely used in the pharmaceutical, cosmetics, chemical, antibacterial, and food industries globally. According to the Food and Agriculture Organization of the United Nations (FAO), China, Indonesia, Korea, the Philippines, and Japan are the top five nations in the world for seaweed production. In recent times, Bangladesh has initiated comprehensive research endeavours focused on seaweed, recognizing its immense potential across diverse sectors. Seaweed in Bangladesh is primarily harvested for various purposes, including food, medicine, and industrial applications. In this study, red seaweed Asparagopsis collected from the coast of Saint Martin’s island of the Bay of Bengal was tested for its bioactive properties like anti-inflammatory and analgesic activity. Anti-inflammatory test was done using carrageenan suspension and three analgesic tests e.g. hot plate test, acetic acid-induced writhing test, and formic acid-induced test were performed in mice model in the laboratory with 50% ethanol extract of Asparagopsis. Following in vivo testing, no significant activity was observed. However, Asparagopsis was found to be rich in phytochemicals like phenols, flavonoids, saponin, glycoside, steroids, tannins, and alkaloids suggesting its importance for future scientific study. This may create a door to a new world in the Blue Economy sector of Bangladesh. Bioresearch Commu. 10(2): 1583-1591, 2024 (July)

THE COMPETITIVENESS OF COMMODITIES SEAWEED USING POLICY ANALYSIS MATRIX (PAM)

Seaweed products from the city of Tarakan have been traded to outside areas such as Makassar and Surabaya before being exported overseas. This study aims to analyze the competitiveness of seaweed in Tarakan City using the policy analysis matrix (PAM) method. The PAM method is used two main indicators for measuring competitiveness, namely the Private Cost Ratio (PCR) as an indicator of competitive advantage and the Domestic Resource Cost Ratio (DRCR) which is an indicator of comparative advantage. The results showed that seaweed in Tarakan City had a PCR value of 0.37 and a DRC of 0.08, the private profit (PP) obtained was Rp 6,444,319 financially has a competitive advantage at the business level farmer. Social profit (PS) of Rp 30,386,901 economically or the economy as a whole has a comparative advantage which means efficient use of resources. The impact of government policies on the output of seaweed cultivation is not protective with an NPCO value of 0.34. The impact of government policies on seaweed cultivation inputs is not protective with an NPCI value of 1.29, meaning that farmers have not received positive incentives from the current input subsidy policy. The EPC value of 0.31 means that the overall impact of government policies on input-output is protective and provides positive incentives to farmers, but is still relatively weak and very vulnerable if policy changes occur. The regional government is expected to provide protection to seaweed cultivators in the form of setting costs for purchasing seaweed and also to strictly supervise cartel practices in the seaweed trading system.

The photosynthetic uptake of inorganic carbon from Pyropia seaweed aquaculture beds: Scaling up population-level estimations

Seaweed aquaculture beds (SABs) contribute positively to CO2 removal (CDR) worldwide. Among cultivated seaweed species, Pyropia represents approximately 8% of the global seaweed production and has the capacity to sequester a significant amount of carbon from the surface layer of the coastal ocean. In this study, we evaluated the carbon uptake efficiency of Pyropia SABs by measuring their photosynthetic rates. Pyropia individuals were collected from Pyropia SABs on the south and west coasts of South of Korea from December to March (cultivation period) in 2016 to 2019, and the photosynthetic light response curves (P-E curves) were measured. Oxygen-based photosyntheses were converted into carbon-based photosynthetic rates using theoretical photosynthetic quotients. Pyropia thallus consumed an average 37 mg C g−1ww d−1, with a high ratio of gross primary production to respiration (P/R ratio; 5–14). To quantify the carbon uptake potential in the coastal areas of South Korea during the cultivation period, we extrapolated the carbon uptake rates using the estimated biomass, total area of Pyropia SABs, and meteorological irradiance data. The highest carbon uptake rate (2143 kt C month−1) was observed in the Southwestern Sea of South Korea in December. Considering all productivity data from the entire cultivation period, approximately 6789 kt C was taken up by the Pyropia SABs. Therefore, our study indicates a significant potential to mitigate climate change by reducing greenhouse gas emissions using Pyropia SABs.

Processing of sugar kelp: Effects on mass balance, nutrient composition, and color

The European production of seaweed, including kelp species, is increasing, but efficient processing schemes for complete biomass valorization are still lacking. In this study, we investigated the effect of combining pulsed electric field (PEF) processing and soaking/blanching treatments (10, 45, and 60 °C) on the chemical composition of sugar kelp. Furthermore, we suggest applications for the various fractions resulting from the different pre-processing steps.More dry matter was extracted from the biomass with increasing degree of processing. Combining PEF and blanching gave the highest extraction yield (˜60 %) compared to only using one of the steps (˜40 %). The extracted compounds contained ash (including iodine), polyphenols, and mannitol. Proteins, heavy metals, other sugars, and (presumably) fiber were concentrated in the solid fractions. Based on the composition, applications within food, feed, agriculture, nutraceuticals, and cosmeceuticals are suggested for the fractions and extracts.These results can be relevant to researchers investigating novel technologies, processing of seaweed, and food safety, as well as to the seaweed industry, for the selection of processing technologies and product applications.