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This capstone project is a completed draft of an illustrated field guide of Southern California seaweeds. The purpose of this was to create a region-specific and user-friendly guide for readers to learn about local seaweeds. This was done by collecting life specimens and illustrating them by hand with watercolor. The illustrations were digitized and put into a draft, along with supporting information about each species. The completed draft will be prepared and submitted for publication in print.

Alginates, hydrophilic anionic polysaccharides with notable bioactivity and biocompatibility, have drawn significant attention, particularly due to their extensive use in the pharmaceutical industry and associated health benefits. Brown seaweeds serve as the primary source of alginates. However, extraction methods, especially traditional ones, face efficiency challenges, impacting the yield. Green extraction methods promise an eco-friendly alternative, but their industrial-scale implementation is still unproven. Importantly, these extraction methods could yield alginates of different molecular weights and consequent varied biological effects. Alginates possess antibacterial, antioxidant, anti-diabetic, and immunomodulatory properties, forming the cornerstone of their health benefits and pharmaceutical applications. The hydrogel formation characteristic of alginates is crucial for pharmaceutical applications, including drug delivery, wound dressing, and tissue regeneration. Despite the existence of numerous articles exploring the extraction methods, properties, and applications of alginates, a gap exists in the literature that connects these aspects with health benefits. This review aims to bridge this gap by providing a comprehensive discussion of the extraction methods, properties, health benefits, and pharmaceutical applications of alginates. [ABSTRACT FROM AUTHOR]

Long used in East Asian cuisine and traditional medicine, the brown seaweed Hizikia fusiformis (also known as Sargassum fusiforme or Hizikia fusiforme) is also referred to as "Hijiki." Given its abundant environmental and bioactive characteristics, it has received considerable attention. This systematic review aimed to present comprehensive data from the existing literature on the environmental and bioactive characteristics of H. fusiformis. Using three databases to search for published studies on related fields between 2002 and 2023, 1344 papers were screened and narrowed down to a set of 49 papers by the predetermined criteria. Evidence shows that H. fusiformis is a promising resource in the environmental protection and bioactive domains. Overall, more research and methods are needed to organically combine the development of H. fusiformis in the environmental and bioactive fields to gain greater economic benefits and environmental protection capabilities. [ABSTRACT FROM AUTHOR]

Aquaculture in exposed and/or distant ocean sites is an emerging industry and field of study that addresses the need to improve food security along with the challenges posed by expansion of urban and coastal stakeholders into nearshore and sheltered marine waters. This move necessitates innovative solutions for this industry to thrive in high-energy environments. Some innovative research has increased understanding of the physics, hydrodynamics, and structural requirements enabling the development of appropriate systems. The blue mussel (Mytilus edulis), the New Zealand green shell or green lipped mussel (Perna canaliculus), and the Pacific Oyster (Magallana gigas), are the primary targets for commercial exposed bivalve aquaculture. Researchers and industry members are actively advancing existing structures and developing new structures and methodologies for these and alternative high-value species suitable for such conditions. For macroalgae (seaweed) cultivation, such as sugar kelp (Saccharina latissimi), oar weed (Laminaria digitata), or kelp sp. (Ecklonia sp.), longline systems are commonly used, but further development is needed to withstand fully exposed environments and improve productivity and efficiency. In marine finfish aquaculture, three primary design categories for open ocean net pens are identified: flexible gravity pens, rigid megastructures, closed pens, and submersible pens. As aquaculture ventures into more demanding environments, a concerted focus on operational efficiency is imperative. This publication considers the commercial and research progress relating to the requirements of aquaculture's expansion into exposed seas, with a particular focus on the cultivation of bivalves, macroalgae, and marine finfish cultivation technologies and structural developments. [ABSTRACT FROM AUTHOR]

Animals combine colour change and behavioural choices to enhance concealment and adapt to changes in habitat in time and space. However, non‐native and invasive habitat‐forming plants and seaweeds can change the landscape, challenging animals to remain camouflaged, especially when the colour of the new habitat differs from the native backgrounds.The chameleon prawn (Hippolyte varians) exhibits remarkable colour variation and effective camouflage against different native seaweeds in shallow tidepools. Individuals optimize crypsis by choosing colour‐matching seaweeds and changing colour over time. In some locations, the prawn's native habitats are now replaced by non‐native seaweeds of different coloration and structure, making it important to understand whether substrate choice and colour change facilitates the occupation of these seaweeds and enables prawns to camouflage against new backgrounds.Using image analysis and visual modelling of a fish predator, we assessed the colour variation and camouflage of chameleon prawns occupying the non‐native seaweeds brown wireweed (Sargassum muticum) and pink harpoon weed (Asparagopsis armata) in southwest UK. We performed laboratory trials to examine whether prawns maintain their preference for colour‐matching native substrates when given a choice between them and non‐native seaweeds, and if they can change their coloration to improve camouflage against non‐native substrates.Prawns exhibit phenotypic diversity and camouflage that varied with the non‐native seaweed species, with low colour variation and effective camouflage on pink harpoon weed, but high colour diversity and reduced concealment against brown wireweed. Prawns choose non‐native seaweeds when the alternative native substrate provides mismatching coloration, but they did not exhibit any preference between colour‐matching native and non‐native seaweeds. Once in non‐native habitats, prawns change their appearance over a few days to match the background, sometimes faster than when changing on native seaweeds of contrasting coloration.Although human activities considerably modify the coloration of marine landscapes by increasing the establishment of non‐native seaweeds, the impacts of those changes appear less severe for colour‐changing species, such as chameleon prawns, and will depend on the similarity between the colour of the new substrates and the original native backgrounds, and how animals use behaviour and physiology to match new habitats. [ABSTRACT FROM AUTHOR]

Energy security is a critical global challenge in the transition to sustainable development. Anaerobic digestion (AD) offers a promising renewable energy solution that mitigates environmental impacts. Algae, as biomass feedstock, have shown significant potential for bioenergy production; however, their complex chemical composition poses challenges to the efficiency of the AD process. To address these limitations, various pretreatment methods have been applied to enhance biogas production. In this study, we performed a comprehensive meta‐analysis to evaluate the effects of different pretreatments on methane (CH₄) yields from both microalgae and macroalgae. Our results demonstrate that biological, physical, and combined chemical–physical pretreatments significantly improve CH₄ production in microalgae, with increases of up to 141%, 125%, and 151%, respectively. For macroalgae, physical pretreatments were the most effective, leading to a 129% increase in CH₄ yield. We also estimate that utilizing just 10% of the global algal biomass production (3.6 Mt) could generate over 5.5 TWh y−1 of energy. This potential could be doubled with the application of appropriate pretreatment strategies. These findings highlight the role of algae in advancing renewable energy production and contribute to the growing body of knowledge on optimizing AD processes for cleaner energy generation. [ABSTRACT FROM AUTHOR]

Characteristics such as calcareous morphology and life cycle are used to understand the ecology of calcified rhodophytes. However, there is limited information regarding their chemical profiles and biological activities. Therefore, a systematic review (PRISMA) was conducted to assess the influence of the chemistry of calcareous rhodophytes on ecological interactions in the marine environment. The keywords used were: ["Chemical AND [Ecology OR Interaction OR Response OR Defense OR Effect OR Cue OR Mediated OR Induce]"] AND ["Red Seaweed" OR "Red Macroalgae" OR Rhodophy?] AND [Calcified OR Calcareous] in Science Direct, Scielo, PUBMED, Springer, Web of Science, and Scopus. Only English articles within the proposed theme were considered. Due to the low number of articles, another search was conducted with three classes and 16 genera. Finally, 67 articles were considered valid. Their titles, abstracts, and keywords were analyzed using IRaMuTeQ through factorial, hierarchical and similarity classification. Most of the studies used macroalgae thallus to evaluate chemical mediation while few tested crude extracts. Some substances were noted as sesquiterpene (6-hydroxy-isololiolide), fatty acid (heptadeca5,8,11-triene) and dibromomethane. The articles were divided into four classes: Herbivory, Competition, Settlement/Metamorphosis, and Epiphytism. Crustose calcareous algae were associated with studies of Settlement/Metamorphosis, while calcified algae were linked to herbivory. Thus, the importance of chemistry in the ecology of these algae is evident,and additional studies are needed to identify the substances responsible for ecological interactions. This study collected essential information on calcified red algae, whose diversity appears to be highly vulnerable to the harmful impacts of ongoing climate change. [ABSTRACT FROM AUTHOR]

The development of trait‐based approaches has accelerated our understanding of how communities assemble, respond to environmental change and may best be managed in the Anthropocene. Understanding the magnitude and pattern of interspecific variability forms a critical underpinning of trait‐based approaches while exploring intraspecific variability can identify the potential of species to adapt to changing environmental drivers. Our work is motivated by the critical need for a novel conceptual framework for understanding the functional ecology of macroalgae, as the current paradigm is still mired in functional group models developed in the 1980s.Our objective was to quantify interspecific and intraspecific functional trait variability in three common and morphologically diverse species of tropical marine macroalgae by exploring traits relating to the ecological functions of resource acquisition, resistance to herbivory, and resistance to physical disturbance and the trade‐offs between them.We quantified intraspecific and interspecific variability of 11 functional traits for three common and morphologically diverse species of tropical macroalgae from five fringing reefs of Mo'orea, French Polynesia that were likely to capture a wide range of environmental variability. Differences in traits among species and sites were determined with PERMANOVA, visualised with non‐metric multidimensional scaling, and trade‐offs between pairs of traits explored with correlation. Finally, spatial patterns among select traits across all species were quantified.Species clustered together in distinctly different trait spaces driven by trade‐offs among suites of functional traits. Two of three species had considerable intraspecific variability, though this variability occurred at different scales, while one clustered tightly. Exploration of individual traits across species and sites revealed trade‐offs between two strategies for resource acquisition, growing tall and strong versus investing in large surface area.Synthesis. We captured novel patterns of interspecific and intraspecific variability for tropical marine macroalgae. We found fundamental differences in traits between species that may represent ecological strategies while considerable intraspecific variability demonstrates a wide range in abilities to respond to environmental drivers. Overall, our work provides novel insights into intra and interspecific trait variation that form an essential underpinning for using a trait‐based framework in a taxon that is increasingly dominant on tropical reefs. [ABSTRACT FROM AUTHOR]

Marine algae, a rich source of bioactive substances, have long been utilized in biomedical and veterinary sciences. This study breaks new ground by assessing the antiviral therapeutic potential of water extracts from four algal species – Colaconema formosanum, Caulerpa microphysa, Gelidium amansii and Sarcodia suae – against vesicular stomatitis virus (VSV) infection. The standout among these was Sarcodia suae water extract (SSWE), which not only significantly repressed VSV replication and enhanced cell survival without cytotoxic effects, but also demonstrated its antiviral activity through interference with viral attachment, entry, RNA replication, and egress, and reduced VSV-induced autophagy in Mv1Lu cells during the late stages of infection. The EC50 of SSWE was 0.422 ± 0.14 mg ml‒1. The cytotoxicity assay confirmed the high biocompatibility of SSWE. This study identifies SSWE as a promising natural antiviral agent and elucidates its mechanisms of action, highlighting the need for further research to optimize its use in controlling VSV-related diseases. Highlights: The bioactive water extract of Sarcodia suae was identified as a sustainable antiviral agent for the algal cultivation industry. The antiviral activity of S. suae against vesicular stomatitis virus (VSV) infection was confirmed. The mechanisms of action of the extract from Sarcodia suae on the autophagic pathway were demonstrated. [ABSTRACT FROM AUTHOR]

The Bangiales are one of the most common seaweeds in sub-Antarctic and Southeastern Pacific upper intertidal habitats. Here we report records of an 'olpidioid' marine obligate parasite infecting Bangiales between 39°20′–41°44′S in the Southeastern Pacific for the first time. The disease resembles the 'Olpidiopsis blight disease' reported for farmed Bangiales in Japan and Korea and wild Pyropia from Scotland morphologically and developmentally. The Chilean isolate infects commercial Chilean laver or 'luche' (Porphyra sensu lato) and Bangia sensu lato from wild populations in the Southeastern Pacific. Phylogenetic markers (cox2, 18S) identify it as Olpidiopsis porphyrae. We relate the occurrence of this pathogen to both 'luche' fisheries in Chile and the potential consequences for its emergent aquaculture in the Southeastern Pacific. Highlights: The parasite Olpidiopsis porphyrae (Oomycota) is reported in Chile and the Southeastern Pacific for the first time. O. porphyrae infects Chilean Porphyra and Bangia sensu lato. The prevalence of O. porphyrae is very variable between populations, and highly seasonal in a locality of Southern Chile. [ABSTRACT FROM AUTHOR]

Beup RA, Felongco SGE, Cailin SJC, Guanzon Jr NG, Fantonalgo RN, Pakingking Jr RV. 2024. Assessing the levels of heavy metals Cd, Cr, and Pb in the naturally occurring red seaweed Gracilariopsis heteroclada in Iloilo Province, Philippines, for potential mass cultivation. Nusantara Bioscience 16: 149-153. The Philippines, a leading exporter of seaweed, has incorporated strategies in its Philippine Industry Seaweed Roadmap (2022-2026) to boost seaweed production. Therefore, to achieve this, potential sites for seaweed cultivation must undergo assessment for heavy metal content. A pilot study assessed heavy metals Cd, Cr, and Pb levels in red seaweed (Gracilariopsis heteroclada) sourced from three locations in Iloilo Province, Philippines: Site 1, a fishpond in Brgy, Nabitasan, Leganes; Site 2, along Dumangas Port coastline in Brgy, Sapao, Dumangas; and Site 3, a fishpond in Brgy, Talokgangan, Banate. Flame atomic absorption spectrometry was employed to analyze heavy metal concentrations. The mean concentrations of Pb in G. heteroclada from Sites 1, 2, and 3 were 5.0129±0.0896, 5.0388±0.8749, and 3.5119±0.9262 mg/kg, respectively; for Cr, they were 3.3002±0.1436, 4.0464±0.3800, and 2.8027±0.1436 mg/kg, respectively. The mean Cd concentrations were also 0.8518±0.0349, 0.8115±0.0202, and 0.5423±0.0419 mg/kg, respectively. Although Cd levels met safety standards, Pb and Cr concentrations exceeded the maximum permissible levels set by the European Union (EU) and China Food and Drug Administration (CFDA), respectively. This suggests that the examined sites may not be suitable for large-scale cultivation due to potential health risks from Pb and Cr exposure through seaweed consumption. Continued monitoring of toxic metal levels in these areas is therefore imperative. [ABSTRACT FROM AUTHOR]

This study evaluated the effects of biostimulants on two varieties of amaranth, Valentina (Amaranthus tricolor) and Nezhenka (Amaranthus hybridus), in terms of germination, growth, and biomass production. Using neutrosophic statistics allowed for the measurement of indeterminacies and the analysis of variables such as days to germination, stem length, number of leaves, and biomass production. The results showed that seaweed extract was the most effective biostimulant, accelerating germination, increasing stem length and the number of leaves, and maximizing biomass production. Meanwhile, Nezhenka stood out for its superior biomass production, especially with seaweed extract, while Valentina was notable for its rapid germination. These findings suggest that the selection of biostimulants and varieties should be strategic to optimize agricultural yield. [ABSTRACT FROM AUTHOR]

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Dakhla Bay is a paralic environment distinguished by various potentialities, including fishing, aquaculture, and tourism. However, the development of these human activities can lead to negative impacts on this environment, posing a threat to human health. This situation requires special attention to the environment and the implementation of a program for the protection and preservation of this ecosystem. This study aims to identify solutions to protect the marine environment from cadmium contamination by the macroalgae Gracilaria gracilis. The results of cadmium analyses in different compartments of Dakhla Bay, including bivalve molluscs, seawater, sediment, and macroalgae, indicate a difference in cadmium accumulation across the various studied compartments. The highest levels of cadmium are noted in macroalgae, with concentrations ranging from a minimum of 0.9 mg/kg fresh weight in the summer of 2019 to a maximum of approximately 2.55 mg/kg fresh weight recorded during the summer of 2022 at the Lassargua station. In comparison, bivalve molluscs such as Perna perna showed Cd levels ranging from 0.2 mg/kg to 1.4 mg/kg fresh weight at the same station. The sediment samples revealed average Cd levels ranging from 0.02 to 1.39 mg/kg dry weight in samples collected from Lassargua, while seawater concentrations were recorded at approximately 0.65 µg/L. The decontamination of cadmium by the macroalgae Gracilaria gracilis without impacting the quality of the algae has been well confirmed. Indeed, cadmium levels noted in macroalgae remain below the thresholds set by the regulations in force. In conclusion, the results of this study encourage the use of algocultures in Dakhla Bay to protect its ecosystem from various types of pollution. [ABSTRACT FROM AUTHOR]

Seaweeds or marine algae with their three main taxa are recognized as a potential pot for numerous products. This has been imperative to valorize their components at an industrial scale in the context of the sustainability goals of the United Nations (UN). Biorefinery approaches have been attempted for several decades to produce bioactive, biofuels, fine chemicals, and nutritional products from seaweeds. However, with the recent UN goals, climatic changes, and the global economic situation, it is essential to assess all the production processes involved concerning several factors. Numerous steps are performed following algae collection, including optimization of downstream processing (e.g., drying, extraction, and purification), in addition to suitable preservation to maintain products' integrity till their usage. Moreover, breakthroughs in biotechnologies and the biological sciences are also targeted to achieve the goals of the blue circular bioeconomy which focuses on renewable resources of foods, drug discovery, and energy, while preserving the ocean ecosystem. Hence, the current article provided new insights into the various processes to valorize marine algae in the frame of circular bioeconomy and sustainability concepts. [ABSTRACT FROM AUTHOR]

Genomic resources have yielded unprecedented insights into ecological and evolutionary processes, not to mention their importance in economic and conservation management of specific organisms. However, the field of macroalgal genomics is hampered by difficulties in the isolation of suitable DNA. Even when DNA that appears high quality by standard metrics has been isolated, such samples may not perform well during the sequencing process. We here have compared Oxford Nanopore long‐read sequencing results for three species of macroalgae to those of nonmacroalgal species and determined that when using macroalgal samples, sequencing activity declined rapidly, resulting in reduced sequencing yield. Chemical analysis of macroalgal DNA that would be considered suitable for sequencing revealed that DNA derived from dried macroalgae was enriched for polyphenol–DNA adducts (DNA with large polyphenols chemically attached to it), which may have led to sequencing inhibition. Of note, we observed the strongest evidence of sequencing inhibition and reduced sequence output when using samples dried using silica gel—suggesting that such storage approaches may not be appropriate for samples destined for Oxford Nanopore sequencing. Our findings have wide‐ranging implications for the generation of genomic resources from macroalgae and suggest a need to develop new storage methods that are more amenable to Oxford Nanopore sequencing or to use fresh flash‐frozen tissue wherever possible for genome sequencing. [ABSTRACT FROM AUTHOR]

Organic carbon (OC) burial in the Antarctic marginal seas is essential for regulating global climate, particularly due to its association with ice shelf retreat. Here, we analyzed total OC (TOC), total nitrogen (TN), radiocarbon isotope, n-alkanes and relative indicators in surface and core sediments from the Ross Sea, West Antarctica. Our aim was to investigate spatial and historical changes in OC sources, and to explore the influencing factors and implications for ice shelf retreat since the last glacial maximum (LGM). Our results revealed distinct spatial patterns of OC sources as indicated by n-alkane indicators in surface sediments. In the Western Ross Sea, n-alkanes predominantly originated from phytoplankton and bacteria, as evidenced by their unimodal distribution, low carbon preference index (CPI) of short-chain n-alkanes (CPIL = 1.41 ± 0.30), and low terrestrial/aquatic ratio (TAR = 0.22 ± 0.14). In the Southwest Ross Sea, n-alkanes were derived from marine algae and terrestrial bryophytes, indicated by bimodal distribution, low ratio of low/high molecular-weight n-alkanes (L/H = 0.62 ± 0.21), low CPI of long-chain n-alkanes (CPIH = 1.18 ± 0.16), and high TAR (1.26 ± 0.66). In contrast, the Eastern Ross Sea exhibited n-alkanes that were a combination of phytoplankton and dust from Antarctic soils and/or leaf waxes from mid-latitude higher plant, as suggested by both unimodal and bimodal distributions, high L/H (1.60 ± 0.58) and CPIH (2.04 ± 0.28), and medium TAR (0.61 ± 0.30). Geologically, during the LGM (27.3 -- 21.0 ka before present (BP)), there was an increased supply of terrestrial OC (TOC/TN = 13.63 ± 1.29, bimodal distribution of n-alkanes with main carbon peaks at nC17/nC19 and nC27). From 21.0 to 8.2 ka BP, as glaciers retreated and temperatures rose, the proportion of marine n-alkanes significantly increased (TOC/TN = 9.09 ± 1.82, bimodal distribution of n-alkanes with main carbon peaks at nC18/nC19 and nC25). From 8.2 ka BP to the present, as the ice shelf continued to retreat to its current position, the marine contribution became dominant (TOC/TN = 8.18 ± 0.51, unimodal distribution of n-alkanes with main carbon peak at nC17/nC18/nC19, and low TAR (0.41 ± 0.32)). This research has significant implications for understanding the variations in Antarctic OC sources and their climatic impacts in the context of accelerated glacier melting. [ABSTRACT FROM AUTHOR]

Pyrenoids are subcompartments of algal chloroplasts that increase the efficiency of Rubisco-driven CO 2 fixation. Diatoms fix up to 20% of global CO 2 , but their pyrenoids remain poorly characterized. Here, we used in vivo photo-crosslinking to identify pyrenoid shell (PyShell) proteins, which we localized to the pyrenoid periphery of model pennate and centric diatoms, Phaeodactylum tricornutum and Thalassiosira pseudonana. In situ cryo-electron tomography revealed that pyrenoids of both diatom species are encased in a lattice-like protein sheath. Single-particle cryo-EM yielded a 2.4-Å-resolution structure of an in vitro TpPyShell1 lattice, which showed how protein subunits interlock. T. pseudonana TpPyShell1/2 knockout mutants had no PyShell sheath, altered pyrenoid morphology, and a high-CO 2 requiring phenotype, with reduced photosynthetic efficiency and impaired growth under standard atmospheric conditions. The structure and function of the diatom PyShell provide a molecular view of how CO 2 is assimilated in the ocean, a critical ecosystem undergoing rapid change. [Display omitted] • Identification of the PyShell, a protein sheath that surrounds diatom pyrenoids • Multiscale imaging of PyShell lattices from in situ architecture to in vitro structure • PyShell knockout disrupts pyrenoid morphology and function, impairing cell growth • The PyShell is widely conserved, enabling much of the ocean's CO 2 fixation Identification and characterization of a protein lattice around the pyrenoid compartments of diatoms reveals that these prolific marine algae evolved a distinct pyrenoid architecture to promote Rubisco's CO 2 -fixing activity. [ABSTRACT FROM AUTHOR]

This study reports on 10 species of the genus Copidognathus Trouessart, 1888 collected from sand sediment habitats and macroalgae in Muğla and Antalya, located along the eastern Mediterranean Sea, Türkiye. Three species, C. cribosoma (Police, 1909), C. figeus Bartsch, 1976 and C. humerosus (Trouessart, 1896) are recorded from the Turkish coasts for the first time, extending their known distribution to the Levantine Sea. Juvenile stages of C. brachyostomus, C. cribosoma, C. gibbus, C. humerosus, C. lamelloides, C. magnipalpus, C. remipes and C. tabellio were also identified and illustrated, with the nymphs of C. cribosoma, C. remipes and the larvae of C. gibbus and C. humerosus being documented for the first time. Additionally, this study provides detailed observations on the adults of C. gibbus, C. majusculatus and C. tabellio which were previously recorded in Türkiye. [ABSTRACT FROM AUTHOR]

The disappearance of canopy-forming algae in coastal habitats exposes crustose coralline algae (CCA) to varying light conditions during the transition from foliose macroalgal habitats to barren ground by physical, chemical, or biological interaction. We hypothesized that the sudden increase in light intensity, resulting from the absence of canopy-forming algae, leads to photodamage in CCA related to inhibition of growth. To test this, a 4-week indoor incubation experiment was conducted under different light intensities (20-, 60-, 120-, and 250-μmol photons m−2 s−1). Results revealed that CCA can acclimate to limited light environments, with the efficiency of PSII significantly reduced at higher light levels. Photoprotective mechanisms were activated under persistent stress, leading to a reduction in encrusting area and CCA bleaching. This suggests that CCA coexist with canopy-forming algae in environments with sufficient light exposure, benefiting from the shade provided. However, if directly exposed to light due to the disappearance of canopy-forming algae, CCA faces extreme light stress and potential disappearance. [ABSTRACT FROM AUTHOR]

AbstractFucose is abundant in marine organisms, primarily as fucoidan and fucosylated chondroitin sulfate. Our previous study characterized a sulfated and fucosylated glucuronomannan (SFGM) isolated from marine brown algae, exhibiting notable antiviral activity and potential for drug development. Herein, a trisaccharide fragment of this SFGM in the form of [α-L-Fuc(2, 4-diS)]-(1→3)-α-D-Man-(1→4)-α-D-GlcA-OMP was synthesized for the first time. Stereoselective formation of the α-1,2-cis-fucosidic bond was achieved by leveraging solvent effects. The sulfated trisaccharide as the final product, featuring a 2,4-diS-fucose unit and the p-methoxyphenyl group as a pendant at the anomeric position, was successfully accomplished. The synthetic strategy developed in this study offers a foundation for the pharmaceutical development of these SFGM oligosaccharides. [ABSTRACT FROM AUTHOR]

Promoting resilience is highly relevant to preserving biodiversity and ecosystem functioning. For coral reefs, parrotfish protection emerged as a mainstream action for reversing the degradation experienced by these systems. The rationale is that restoring their populations will increase grazing activity and reinforce control of fast‐growing macroalgae, facilitating coral cover recovery. A lack of a link between parrotfish trends and macroalgae and coral cover trends at a large scale has, however, often been the case. Suggesting more complex underlying dynamics that should be reexamined. In this review, we discuss how lumping parrotfish species as if they were functionally redundant may obscure trends. And how a lack of appreciation of other functions around the parrotfish paradigm, specifically bioerosion, may have unforeseen and potentially adverse effects on degraded reefs. We show that bioerosion responded more directly and quickly to spatial and temporal changes in parrotfish assemblages than macroalgae consumption, arguably due to the varying vulnerability among Caribbean parrotfishes to fisheries and habitat loss. For highly degraded reefs, positive changes in parrotfish populations could hence compromise the remaining coral skeleton structures and the reef framework, further accentuating reef degradation, where increases in macroalgae consumption could not necessarily compensate for higher rates of bioerosion. [ABSTRACT FROM AUTHOR]

This study focuses on a rare sail-shaped macrofossil, Alienum velamenus gen. & sp. nov. from the Jiangchuan Biota in Yunnan Province, China. The new species presented here possesses an unique bipartite body consisting of a wide unbranched, asymmetrical sail-shaped anterior section and a small narrow tail-like posterior section. The macrofossil of the new species is preserved through carbonaceous compression. Its appearance is different from known macroalgae but similar to Vetulicolia from the early Cambrian Chengjiang Biota. The anterior section of the new species, which is broad and smooth, shows only indistinctly arranged suspected gill slits and a nearly horizontal pharyngeal groove, without significant segmented structures. Owing to lack of samples, the specific biological properties and taxa of the new species are still undefined. The discovery of Alienum velamenus indicates that the Jiangchuan Biota is an exceptional lagerstätte with great potential for the preservation of Precambrian early life through carbonaceous compression. Furthermore, the Jiangchuan Biota shows significant differences in species diversity from the Miaohe Biota of the Doushantuo Formation and the Shibantan Biota of the Dengying Formation in the Three Gorges area of Hubei Province. [ABSTRACT FROM AUTHOR]

Molecular biomarker and whole oil carbon isotope (δ13Coil) analyses were conducted on eleven typical crude oils from the Qiongdongnan Basin to investigate their biological sources and depositional environments. Saturated hydrocarbon biomarkers in most samples are characterized by angiosperm-derived compounds, with aromatic compounds dominated by the naphthalene, phenanthrene, biphenyl, and fluorene series. The related source rocks of these oils were mainly deposited under oxic condition, but a subanoxicesuboxic and enclosed water column condition in the Central Depression during Oligocene. The identification of simonellite and related compounds in the aromatic fractions provides reliable evidence for the input of coniferous gymnosperms. Cadalene may also have a potential association with gymnosperms since it shows a strong positive correlation with simonellite. Evidence from density, nalkanes, short-chain alkylbenzenes and secondary brine inclusions indicates that the unique crude oil B13-1 may have suffered from thermal alteration. These crude oils (excluding B13-1) can be classified into four types based on the δ13Coil values and molecular biomarkers. Type A oil (solely S34-3) is characterized by non-angiosperm plants, with minor dinoflagellates and increasing contribution from conifer gymnosperms than others. Type B oils (L17-2, L18-1, L25-1, and L25-1W) show heavy δ13Coil (-24 ‰ to -25 ‰) and mixed contributions from both angiosperms and marine algae, with the marine algae contribution increasing. Type C oils (L13-2 and B21-1) share similar biological sources with Type B, but the moderately δ13Coil (-25‰ to -26‰) and high level of terrestrial biomarkers suggesting a predominant contribution of angiosperms. Type D oils (Y13-1a, Y13-1b, and Y13-4) possess the lightest δ13Coil (mainly below -26‰) and are primarily derived from angiosperms, with mangrove vegetation playing an important role. Spearman correlation analysis among 14 source biomarker parameters with δ13Coil and geological setting of related source rocks implied that the marine algae should be responsible for the heavy δ13Coil in the Type B. The contribution of marine algae in the Central Depression may have been neglected in the past, as it is usually covered by remarkable angiosperm biomarkers. [ABSTRACT FROM AUTHOR]

Artificial Light at Night (ALAN) is an emerging global stressor that is likely to interact with other stressors such as warming, affecting habitat‐forming species and ecological functions. Seaweeds are dominant habitat‐forming species in temperate marine ecosystems, where they support primary productivity and diverse ecological communities. Warming is a major stressor affecting seaweed forests, but effects of ALAN on seaweeds are largely unknown. We manipulated ALAN (0 lx vs. 25 lx at night) and temperature (ambient vs. +1.54°C warming) to test their independent and interactive effects on the survival, growth (biomass, total‐, blade‐ and stipe‐length) and function (photosynthesis, primary productivity and respiration) on the juveniles of two habitat‐forming seaweeds, the kelp Ecklonia radiata and the fucoid Sargassum sp. Warming significantly increased Ecklonia mortality; however, ALAN did not affect mortality. ALAN had positive effects on Ecklonia biomass, total and blade growth rates and gross primary productivity; however, warming largely counterbalanced these effects. We found no significant effects of warming or ALAN on Ecklonia photosynthetic yield, stipe length, net primary productivity or respiration rates. We found no effects of ALAN or warming on Sargassum for any of the measured variables. Synthesis. Our findings indicate that ALAN can have positive effects on seaweed growth and functioning, but such effects are likely species‐specific and can be counterbalanced by warming, suggesting an antagonistic interaction between these global stressors. These findings can help us to predict and manage the effects of these stressors on seaweeds, which underpin coastal biodiversity. [ABSTRACT FROM AUTHOR]

This study investigates the diversity and ecological dynamics of macroalgae in Maxwell Bay, King George Island, Antarctica, focusing on species distribution, substrate composition, and interspecific interactions. Across nine survey sites, 31 macroalgal species were recorded, with 12 species identified as significant due to their considerable relative frequency, coverage, and biomass. Palmaria decipiens was the most dominant species in terms of frequency and coverage, while Desmarestia anceps had the highest biomass. The study revealed distinct substrate preferences, with P. decipiens favoring cobble and mud substrates, and Himantothallus grandifolius associating predominantly with pebble substrates. A core group of species, including Plocamium sp., H. grandifolius, Picconiella plumosa, Iridaea sp., and Trematocarpus antarcticus, exhibited strong ecological interactions characterized by high substrate similarity and mutual affinity. In contrast, pioneer species like P. decipiens and Monostroma hariotii showed lower affinity with other species, reflecting their early successional roles. These findings enhance our understanding of the complex interspecific relationships within Antarctic macroalgal assemblage and provide valuable baseline data for future ecological studies in the region. [ABSTRACT FROM AUTHOR]

Seaweed farming is the single largest aquaculture commodity with >30 million tonnes produced each year. Furthermore, the restoration of lost seaweed forests is gaining significant momentum, particularly for kelps in warming temperate areas. Whether in aquaculture settings, following restoration practices, or in the wild, all seaweeds undergo biotic interactions with a diverse range of co‐occurring or cocultured organisms. To date, most research assessing such biotic interactions has focused on the response of the organism interacting with seaweeds, rather than on the seaweeds themselves. However, understanding how seaweeds respond to other organisms, particularly on a molecular scale, is crucial for optimizing outcomes of seaweed farming or restoration efforts and, potentially, also for the conservation of natural populations. In this systematic review, we assessed the molecular processes that seaweeds undergo during biotic interactions and propose priority areas for future research. Despite some insights into the response of seaweeds to biotic interactions, this review specifically highlights a lack of characterization of biomolecules involved in the response to chemical cues derived from interacting organisms (four studies in the last 20 years) and a predominant use of laboratory‐based experiments conducted under controlled conditions. Additionally, this review reveals that studies targeting metabolites (70%) are more common than those examining the role of genes (22%) and proteins (8%). To effectively inform seaweed aquaculture efforts, it will be crucial to conduct larger scale experiments simulating natural environments. Also, employing a holistic approach targeting genes and proteins would be beneficial to complement the relatively well‐established role of metabolites. [ABSTRACT FROM AUTHOR]

Seaweeds are widely assumed to be phenotypically plastic across hydrodynamic gradients, yet while many marine macroalgae exhibit intraspecific phenotypic variation that correlates with flow, researchers often fail to test whether such variation is due to plasticity or another mechanism, such as local adaptation. In this minireview, we considered mechanisms for sensing flow in seaweeds that could facilitate adaptive phenotypic plasticity across hydrodynamic gradients. We then reviewed the literature from 1900 to 2024 to see how often phenotypic variation and plasticity across hydrodynamic gradients had been observed and demonstrated in different groups of seaweeds. In the last 124 years, phenotypic variation and plasticity in response to flow have been well documented in brown algae but scarcely documented in red and green algae. This could suggest that brown algae are better able to sense and respond to flow than red and green algae, perhaps due to the intercalary meristem of many brown algae, including most kelps. However, this skewed distribution could also be the result of publication bias, as most studies involving flow have been conducted on brown algae. Only 30% of 141 papers specifically investigated if observations of phenotypic variation along hydrodynamic gradients were due to plasticity. To date, phenotypic plasticity in response to flow has been demonstrated in 20 brown algal species, five red algal species, and two green algal species. Thus, the assumption that phenotypic plasticity to flow is common across seaweeds is not particularly well supported by the literature. Mechanisms underlying plasticity to flow are poorly understood and remain a critical avenue for future research. [ABSTRACT FROM AUTHOR]

Understanding how macroalgal forests will respond to environmental change is critical for predicting future impacts on coastal ecosystems. Although measures of adult macroalgae physiological responses to environmental stress are advancing, measures of early life‐stage physiology are rare, in part due to the methodological difficulties associated with their small size. Here we tested a novel, high‐throughput method (rate of oxygen consumption and production; V̇O2$$ \dot{V}{\mathrm{O}}_2 $$) via a sensor dish reader microplate system to rapidly measure physiological rates of the early life stages of three habitat‐forming macroalgae, the kelp Ecklonia radiata and the fucoids Hormosira banksii and Phyllospora comosa. We measured the rate of O2 consumption (respiration) and O2 production (net primary production) to then calculate gross primary production (GPP) under temperatures representing their natural thermal range. The V̇O2$$ \dot{V}{\mathrm{O}}_2 $$ microplate system was suitable for rapidly measuring physiological rates over a temperature gradient to establish thermal performance curves for all species. The V̇O2$$ \dot{V}{\mathrm{O}}_2 $$ microplate system proved efficient for measures of early life stages of macroalgae ranging in size from approximately 50 μm up to 150 mm. This method has the potential for measuring responses of early life stages across a range of environmental factors, species, populations, and developmental stages, vastly increasing the speed, precision, and efficacy of macroalgal physiological measures under future ocean change scenarios. [ABSTRACT FROM AUTHOR]

Algal turf on coral reefs can transition from short productive forms to longer less productive forms that often form a persistent degraded state. We evaluated whether adjacent communities, such as stands of the macroalga Turbinaria ornata, can drive these transitions in Moorea, French Polynesia. We first found that T. ornata stands that overhang turf reduced growth as restricting canopy movement increased turf height compared to controls, implying an overhanging T. ornata canopy shades or abrades adjacent turf. Second, we manipulated T. ornata presence (intact/completely removed) and herbivore access (uncaged/caged) and found that, in the presence of herbivores, removal of stands reduced the height of adjacent turf compared to plots adjacent to intact Turbinaria stands. The presence of intact stands also deterred grazing, demonstrating they provide a refuge for adjacent turf. Thus, algal turf derives both benefits and costs of proximity to macroalgal stands. It is imperative to explore the relative strengths of these costs and benefits as these interactions may drive local transitions to degraded algal states. [ABSTRACT FROM AUTHOR]

Summary: The impact of the addition of seaweed to yoghurt was evaluated on its physicochemical, functional and sensory properties. Two different species of brown macroalgae, Saccharina latissima (blanched or not) and Alaria esculenta, were added in four different concentrations (0.25%, 0.50%, 0.75% and 1%) and in two different forms (flakes and powder). The titratable acidity of all yoghurt samples formulated with blanched Saccharina was similar to the control. However, formulations with blanched Saccharina exhibited higher syneresis than the control. Most yoghurt samples containing Alaria at higher concentrations exhibited a lower firmness than the control. Seaweed addition had a significant impact on the colour of yoghurt samples. Quantitative descriptive analysis and hedonic evaluation performed by a trained panel showed that changes in physicochemical properties influenced the organoleptic characteristics of yoghurt samples. Yoghurt samples formulated with 0.25% S. latissima and 0.50% A. esculenta in flakes were selected as the most promising formulations. [ABSTRACT FROM AUTHOR]

Ocean currents are a crucial means of dispersing natural and human-made materials on the ocean surface. Macroalgae are among the most conspicuous natural dispersers, often called the 'tumbleweeds of the ocean.' Despite numerous studies on the subject, the relative influence of wind and surface currents on the trajectory of macroalgal dispersal remains uncertain. Previous studies have focused on kelp rafts of varying sizes, making it challenging to determine the impact of wind versus currents. These studies have also disregarded the macroalgae's drag characteristics and surface area, which have been shown to impact the trajectory and accumulation of floating flotsam. This numerical study aims to shed light on the relative influence of wind and currents and the role of drag in determining the course and accumulation of macroalgae. By comparing simulations of virtual kelp 'particles' that incorporate drag and those without, this study focused on solitary kelp plants and considered the impact of morphological characteristics, flow-field combinations, and the presence of Stokes drift. Our results show that virtual kelp particles generally followed ocean currents, but the inclusion of drag caused deviations from purely Lagrangian particles' trajectories and sheds light on the complex interplay of factors affecting macroalgal dispersal in the ocean. [ABSTRACT FROM AUTHOR]

The non-food segment of the Chinese seaweed market, which is crucial for developing the hydrocolloid industry, relies heavily on the seaweed supply from Chile, Peru, and, to a much lesser extent, Indonesia, in addition to domestic production. In this paper we investigate the degree of market integration between seaweed from these countries. We find that the market is highly integrated as the Law of One Price holds, suggesting a global market. Furthermore, the import price from Chile and Indonesia follows the lead of the import price from Peru. As the hydrocolloid industry develops in China, increased demand for seaweed from Chile and Peru is expected, which increases the extraction of seaweed from natural beds. This situation will be unsustainable if Chile and Peru continue to rely primarily on wild extraction. [ABSTRACT FROM AUTHOR]

The marine algae Ulva spp. are commonly used as model biofouling organisms. As biofouling studies are primarily conducted using field-collected specimens, factors including species identity, seasonal availability, and physiological status can hinder the replicability of the results. To address these limitations, a protocol was developed for the on-demand laboratory culture and release of Ulva zoospores. The biofouling potential of laboratory-cultured and field-collected Ulva blades was compared using a waterjet. No significant differences were found between field and laboratory-cultured samples in either spore adhesion (before waterjet) or the proportion of spores retained after waterjet exposure. However, there was significant variability within each session type in pre- and post-waterjet exposures, indicating that spore adhesion and retention levels vary significantly among trial runs. In addition, all our laboratory cultures were Ulva Clade C (LPP complex). In contrast, our field samples contained a mix of Ulva Clade C, U. compressa clade I, and U. flexuosa Clade D. This protocol for on-demand production of Ulva spores can improve biofouling research approaches, enables comparison of results across laboratories and regions, and accelerate the development of anti-biofouling strategies. [ABSTRACT FROM AUTHOR]

Cognitive impairments are frequently reported after ischemic strokes. Novel and effective treatments are required. This study aimed to develop a functional ingredient obtained from marine algae and to determine the effect of the extract on antioxidative stress, as well as neuroprotective effects, in a rat model of MCAO-induced ischemic stroke. Among the selected marine algal extracts, Sargassum polycystum displayed the highest total phenolic content and antioxidative potential, and was subsequently used to evaluate cognitive function in rat models of ischemic stroke. The S. polycystum extract, administered at doses of 100, 300, and 500 mg/kg BW, significantly improved cognitive function by enhancing cognitive performance in the Morris water maze and novel object recognition tests. Biochemical changes revealed that providing S. polycystum increased the activities of SOD, CAT, and GSH-Px by 52.48%, 50.77%, and 66.20%, respectively, and decreased the concentrations of MDA by 51.58% and S100B by 36.64% compared to the vehicle group. These findings suggest that S. polycystum extract may mitigate cognitive impairment in ischemic stroke by reducing oxidative stress and inhibiting S100B expression, thus highlighting its potential as a functional ingredient for drugs and nutraceuticals aimed at neuroprotection. [ABSTRACT FROM AUTHOR]

Dynamic models of sugar kelp (Saccharina latissima) growth are used to estimate the production potential of seaweed aquaculture in many regions around the world. These models do not currently account for the existence of S. latissima ecotypes that are adapted to regional environmental conditions, particularly temperature. We tested the hypothesis that recalibrating the temperature parameters of a dynamic energy budget model using literature data for S. latissima from regions with a similar climate to the region of interest would result in more accurate predictions than using a general species‐wide temperature response curve. Calibrating the model using data from warm regions significantly improved model accuracy for kelp cultivation at the southern end of the species range (Rhode Island, USA) in cases where the original parameters underestimated growth but resulted in drastic overestimates when heavy frond erosion occurred. In Trømso, Norway, a cold parameterization produced extremely accurate predictions: the model predicted a final frond length of 88.2 cm, compared with the observed length of 87.5 (±4.70) cm. Our results demonstrate that recalibrating temperature response curves allows one model to be applied to kelp aquaculture in different regions, an important step toward the prediction of S. latissima productivity over large areas. [ABSTRACT FROM AUTHOR]

AbstractSargassum polycystum is among the seaweed species in the Philippines that are considered coastal waste after drifting on the shorelines. Although there has been a report on the potential of S. polycystum as a biostimulant for certain crops, its utilization as a hydroponic nutrient solution is not yet thoroughly analyzed. Thus, a study utilizes various ratios of S. polycystum seaweed extract (SE) mixed with commercial hydroponic nutrient solution (CHNS) to the growth and yield of green leaf lettuce grown under the Kratky method of hydroponic system. Treatments are 100% CHNS and percentage replacements of CHNS with SE (25%, 50%, and 75%, respectively). The result shows a 10.53% increase in lettuce plant height grown under 25% and 50% SE compared to 100% CHNS. A similar result is also observed in the lettuce leaf width (14.29%), leaf length (7.14%), and plant weight (22.41%). Regarding root length, replacing 50% SE resulted in longer root length (44.83%) and more leaves (10%) compared to lettuce plants grown under 100% CHNS. However, replacement of SE beyond 50% is detrimental to leaf length and comparable to all growth and yield parameters with 100% CHNS. Regarding the return on investment, 50% SE replacement has the highest return of 98.62% compared to 100% CHNS, with 49.87% only for a projected six cropping cycles. Hence, a 50% replacement of CHNS with SE from its recommended rate can be suggested for more profitable production of green leaf lettuce under a hydroponic system. [ABSTRACT FROM AUTHOR]

Microalgae and seaweed have been consumed as food for several decades to combat starvation and food shortages worldwide. The most famous edible microalgae species are Nostoc, Spirulina, and Aphanizomenon, in addition to seaweeds, which are used in traditional medicine and food, such as Nori, which is one of the most popular foods containing Pyropia alga as a major ingredient. Recently, many applications use algae-derived polysaccharides such as agar, alginate, carrageenan, cellulose, fucoidan, mannan, laminarin, ulvan, and xylan as gelling agents in food, pharmaceuticals, and cosmetics industries. Moreover, pigments (carotenoids particularly astaxanthins, chlorophylls, and phycobilins), minerals, vitamins, polyunsaturated fatty acids, peptides, proteins, polyphenols, and diterpenes compounds are accumulated under specific cultivation and stress conditions in the algal cells to be harvested and their biomass used as a feedstock for the relevant industries and applications. No less critical is the use of algae in bioremediation, thus contributing significantly to environmental sustainability. This review will explore and discuss the various applications of microalgae and seaweeds, emphasising their role in bioremediation, recent products with algal added-value compounds that are now on the market, and novel under-developing applications such as bioplastics and nanoparticle production. Nonetheless, special attention is also drawn towards the limitations of these applications and the technologies applied, and how they may be overcome. [ABSTRACT FROM AUTHOR]

Given the necessity for bioprocesses scaling-up, the present study aims to explore the potential of three marine cyanobacteria and a consortium, cultivated in semi-continuous mode, as a green approach for i) continuous exopolysaccharide-rich biomass production and ii) removal of positively charged metals (Cu, Ni, Zn) from mono and multi-metallic solutions. To ensure the effectiveness of both cellular and released exopolysaccharides, weekly harvested whole cultures were confined in dialysis tubings. The results revealed that all the tested cyanobacteria have a stronger affinity towards Cu in mono and three-metal systems. Despite the amount of metals removed per gram of biomass decreased with higher biosorbent dosage, the more soluble carbohydrates were produced, the greater was the metal uptake, underscoring the pivotal role of released exopolysaccharides in metal biosorption. According to this, Dactylococcopsis salina 16Som2 showed the highest carbohydrate productivity (142 mg L−1 d−1) and metal uptake (84 mg Cu g−1 biomass) representing a promising candidate for further studies. The semi-continuous cultivation of marine cyanobacteria here reported assures a schedulable production of exopolysaccharide-rich biosorbents with high metal removal and recovery potential, even from multi-metallic solutions, as a step forward in the industrial application of cyanobacteria. [Display omitted] • Semi-continuous cultivation ensures consistent, schedulable biosorbent production. • Marine cyanobacteria show higher affinity to Cu than Ni and Zn dissolved in water. • Up to 84 mg Cu per gram of dry weight were removed by D. salina 16Som2. • The presence of soluble EPS improves metal uptake. [ABSTRACT FROM AUTHOR]

Vegetated coastal marine ecosystems are projected to expand northwards in the Arctic due to climate change, but the mechanisms for this expansion are complex and nuanced. Macroalgal biomass in the littoral areas of Svalbard has been increasing, but data at the glacier fronts are very scarce. In this study, we use hydroacoustics and video validation from an unmanned surface vehicle to survey macroalgal bed distribution along the coast of a High Arctic fjord (Billefjorden, Svalbard), including river bays and land- and sea-terminating glacier fronts, as well as oceanographic measurements to indicate physical drivers of macroalgal settlement. We found high variation of macroalgal coverage along the fjord coastline, with virtually no macroalgae in the river bays but abundant coverage in areas with little terrestrial runoff. Furthermore, the presence of kelp was found at the land-terminating glacier front which has recently retreated from the sea, which suggests the potential for rapid macroalgal establishment in newly available substrate following glacial retreat. These findings suggest large ecological implications throughout the Arctic, in which macroalgal expansion may lead to significant changes in the underwater coastal landscape and ecosystem. This study shows that the use of remote autonomous vehicles and hydroacoustic mapping with video validation has a high potential for sustainable and efficient ecological monitoring. [ABSTRACT FROM AUTHOR]

Inspired from seaweed swayed by waves, the enhanced hydrogen evolution is realized in porous and hybrid g‐C3N4/Pt‐PVDF electrospun membranes via piezoelectricity from water flow energy. The membranes are fabricated by dispersing g‐C3N4/Pt into the mixed solution of PVDF and PEO, followed by electrospinning and selective removal of PEO. By changing the PEO amount, the pore size in nanofibers is adjusted. Due to the hydrogen bonding between g‐C3N4/Pt and PVDF, the β phase of PVDF is increased, beneficial for the piezoelectricity performance. When the electrospun membranes are exposed to water flow, an additional potential field is triggered due to the deformation of PVDF. It not only eases the photogeneration of charge carriers from g‐C3N4/Pt but also hinders their recombination. The prolonged lifetime significantly improves the photocatalytic water splitting of g‐C3N4/Pt under visible light. The hydrogen evolution in the electrospun membranes (PVDF to PEO = 4:1) is profoundly improved to 9 278 µmol h−1 g−1, almost doubled to the pure g‐C3N4/Pt nanosheets (5 220 µmol h−1 g−1). Therefore, the seaweed‐inspired electrospun membrane is a promising strategy for the efficiently photocatalytic water splitting via g‐C3N4 in an aqueous environment, such as a natural sea and lake, by the piezoelectricity gained from the water flow energy. [ABSTRACT FROM AUTHOR]

Drought is one of the most serious challenges facing agriculture and ecosystems around the world. With more frequent and more extreme weather events, the effects of drought are becoming more severe, leading to yield losses, soil depletion and environmental degradation. In this work, we present an analysis of the impact of a marine algae biostimulanat andits ability to offset the effects of drought stress in blueberry cultivation. The aim of the research was to evaluate various fertilisation programs in increasing plant resistance to abiotic stress such as drought. It was tested whether the algal biostimulator provides the same tolerance to drought stress in highbush blueberry plants as regular fertilisers without biostimulation. The research was conducted in 2022 in a greenhouse in controlled drought conditions. Three-year-old highbush blueberry bushes (12 pieces) were used in the experiment. Highbush blueberry bushes (Vaccinium corymbosum) 'Brigitta Blue' varieties were planted in plastic pots with a capacity of 10 dm3 containing an acidic substrate and placed in a greenhouse. Controlled lighting conditions were maintained using sodium lamps and a temperature of 25°C/20°C day/night. The substrate in pots was maintained at 80% of field water capacity by manual watering and weekly supply of nutrient solution for 5 weeks until water deficit occurred. Half of the plants were sprayed weekly with biostimulant at a concentration of 1%, three times 1 week apart (1 application per week). The biostimulant was evenly applied to the entire plant. Seven days after the third application of the product, half of the unsprayed and sprayed plants were subjected to water deficit stress by holding thewatering until 40% of the field water capacity (FC) was reached. The experimental layout included four combinations: C—Control—no biostimulation, no water deficit; CS—Stress control—water deficit up to 40% FC, no biostimulation; B—Biostimulator—no water deficit, biostimulation; BS—Stress plus biostimulator—water deficit up to 40% FC, biostimulation. Fertilisers with seaweed extracts show the ability to reduce the adverse effects of stress, promoting plant resilience, including tolerance to drought stress. The following were evaluated in the experiment: catalase activity, peroxidase activity, free malondialdehyde content, photosynthetic activity and leaf mineral content. The biostimulant used in experiment increased the oxidative activity of the enzymes pe-roxidase and catalase under simulated drought stress conditions. The algal biostimulant increased the average value of catalase activity by 20% in comparison to the control plants, in both combinatinations. The tested biostimulator had no effect on the chlorophyll content in the leaves or the concentration of nutrients in the leaves. The effect of marine algae products on the yield quantity and high quality is related among other to bioactive substances which helps to prevent drought stress. [ABSTRACT FROM AUTHOR]

Five Australian seaweed species, Phyllosphora comosa, Ecklonia radiata, Durvillaea potatorum, Sargassum fallax, and Cystophora siliquosa, thrive along the country's shorelines. Some of these seaweeds have recognized health benefits but have not been fully investigated in terms of their bioactive components and mechanisms of action. We employed ultrasonication with 70% methanol to extract phenolic compounds from these seaweeds and investigated a range of bioactivities for these extracts, including anti‐inflammatory activity exploring urease inhibition, nitric oxide scavenging activity, protein denaturation inhibition, and protease inhibition. Anti‐diabetic activities were investigated using α‐amylase and α‐glucosidase inhibition assays. Anti‐proliferative and anti‐mitotic activities were evaluated using yeast‐cell and green‐gram models, respectively. Our findings showed that C. siliquosa inhibited nitric oxide, urease, and protease activities, with S. fallax, P. comosa, and E. radiata exhibiting substantial inhibition of protein denaturation. E. radiata displayed inhibitory effects on both α‐amylase and α‐glucosidase, whereas P. comosa targeted only the α‐glucosidase enzyme, indicating different mechanisms of anti‐diabetic activity. In these anti‐mitotic assays, C. siliquosa exhibited low cell viability and a significant anti‐proliferative effect, particularly within 24 h, while E. radiata demonstrated notable inhibition at 48 h. LC‐ESI‐QTOF‐MS/MS investigation identified 48 phenolic compounds, including 19 phenolic acids, 20 flavonoids, and 9 other polyphenols. The presence of these compounds in extracts correlated with observed biological activities. These results support the potential health benefits of these seaweeds and link this activity to the presence of bioactive phenolics. [ABSTRACT FROM AUTHOR]

Rationale: 1,2‐Diacyl‐sn‐glycero‐3‐phospho‐O‐[N‐(2‐hydroxyethyl)glycines] (PHEGs) are a class of rare aminophospholipids found specifically in brown algae, including kombu seaweed. Despite their potential importance in algal physiology, a comprehensive mass spectrometry (MS) characterization, useful to understand their biological behaviour, is still lacking. Methods: To establish the structural regiochemical features of PHEGs, we employed hydrophilic interaction liquid chromatography (HILIC). Following separation, the isolated band of PHEGs was analyzed using MS techniques. This included multistage tandem MS experiments, performed in both positive and negative electrospray ionization modes at low and high resolution. Results: By comparing MS/MS and MS3 spectra acquired in negative ion mode, the regiochemical rules for PHEG identification were established. The most abundant PHEG species in kombu seaweed, from both Laminaria ochroleuca (European Atlantic) and Laminaria longissima (Japan), was identified as PHEG 20:4/20:4. Less abundant species included PHEG 20:4/20:5 and hydroxylated forms of both PHEG 20:4/20:4 (i.e. 40:8;O) and 20:4/20:5 (40:9;O). The presence of a lyso PHEG 20:4 was consistently detected but at very low levels. Conclusions: This study employed MS analysis to elucidate the regiochemical patterns of PHEGs in kombu seaweed. We identified PHEG 20:4/20:4 as the dominant species, along with several less abundant variants, including hydroxylated forms. These findings provide valuable insights into the potential roles and metabolism of PHEGs in brown algae, paving the way for further investigation into their biological functions. [ABSTRACT FROM AUTHOR]

Marine microbes that have for eons been adapted to stable salinity regimes are confronted with sudden decreases in salinity in the Arctic Ocean. The episodic freshening is increasing due to climate change with melting multi-year sea-ice and glaciers, greater inflows from rivers, and increased precipitation. To investigate algal responses to lowered salinity, we analyzed the responses and acclimatation over 24 h in a non-model Arctic marine alga (pelagophyte CCMP2097) following transfer to realistic lower salinities. Using RNA-seq transcriptomics, here we show rapid differentially expressed genes related to stress oxidative responses, proteins involved in the photosystem and circadian clock, and those affecting lipids and inorganic ions. After 24 h the pelagophyte adjusted to the lower salinity seen in the overexpression of genes associated with freezing resistance, cold adaptation, and salt tolerance. Overall, a suite of ancient widespread pathways is recruited enabling the species to adjust to the stress of rapid salinity change. The authors analyzed the response of an Arctic pelagophyte to lowered salinity. They observed that several ancient and widespread pathways were activated, allowing the species to adjust to the stress of rapid salinity change. [ABSTRACT FROM AUTHOR]

To investigate the effects of ocean acidification (OA) and nitrogen limitation on macroalgae growth and photophysiological responses, Gracilariopsis lemaneiformis was cultured under two main conditions: ambient (Low CO2, LC, 390 matm) and CO2 enriched (High CO2, HC, 1000 matm), with low (LN, 7 mmol L-1) and high (HN, 56 mmol L-1) nitrate. High CO2 levels decreased growth under both LN and HN treatments. HC reduced Chl a, carotenoids, phycoerythrin (PE), and phycocyanin (PC) under HN conditions, while only Chl a decreased under LN conditions. NO3 - uptake rate was restricted under LN compared to HN, while HC enhanced it under HN. Net photosynthetic O2 evolution rates did not differ between CO2 and nitrate treatments. Dark respiration rates were higher under HN, further boosted by HC. The stimulated effective quantum yield (Y(II)) corresponded to decreased non-photochemical quenching (NPQ) under HN conditions. Nitrate, not CO2, showed significant effects on the relative electron transport rate (rETRmax), light use efficiency (a) and saturation light intensity (Ik) that with lowered rETRmax and a under LN culture. Our results indicate that OA may negatively affect Gracilariopsis lemaneiformis growth and alter its photophysiological performance under different nutrient conditions. [ABSTRACT FROM AUTHOR]

The experiment was to investigate the effects of three species of macroalgae on the growth performance, physiology and biochemistry index of juvenile largemouth bass. A total of 360 juvenile largemouth bass with an initial body weight of (6.04±0.03) g were randomly divided into four groups with three replicates per group and 30 perca per replicate. Group C (Control Group) was fed a basic diet, while Groups T1, T2, and T3 were fed the basic diet supplemented with 5% Gracilaria lemaneiformis powder, 5% Asparagopsis taxiformis powder, and 5% Sargassum powder, respectively, with each group's diet being isonitrogenous and isocaloric. The experiment lasted for 57 days. The results showed that compared to Group C, the feed intake rate and feed coefficient of all experimental groups was significantly increased (P<0.05), and the protein deposition rate and fat deposition rate of Groups T2 and T3 were significantly decreased (P<0.05). The whole fish moisture content of Groups T2 and T3 was significantly increased (P<0.05), while the crude protein and crude fat concentrations were significantly decreased (P<0.05). The crude fat content in the liver of Groups T2 and T3 was significantly decreased (P<0.05). The study shows that the diet with 5% Gracilaria lemaneiformis powder, Asparagopsis taxiformis powder, and Sargassum powder respectively does not affect the growth of juvenile largemouth bass, but can improve its feeding rate and reduce the crude fat of the whole body and liver, and overall effect of juvenile largemouth bass supplemented with Sargassum powder feed is the best. [ABSTRACT FROM AUTHOR]

Heribaudiella fluviatilis (Areschoug) Svedelius is one of the rare representatives of freshwater brown algae, and its range is restricted to the Northern Hemisphere. Hildenbrandia rivularis (Liebmann) J. Agardh is still one of the endangered red algae species in Europe, although its indicator value and distribution have recently been questioned. The association Hildenbrandio rivularis– Heribaudielletum fluviatilis Fritsch 1929 corr. Täuscher 2020 occurs mainly in Northern and Central Europe, while its occurrence and ecology in Southern Europe are poorly researched. The lower reaches of the Nera River near the small town of Bela Crkva, Serbia, were searched for macroalgae in August 2021 and June 2022, when stones with macroalgal crusts were collected. Environmental parameters were measured in situ and water samples were collected for further analysis. A sample of the epilithic diatom community was collected to calculate diatom indices. We present the occurrence of the association Hildenbrandio rivularis–Heribaudielletum fluviatilis in the lower course of the Nera River in Serbia, relating the ecology of the species and habitat to previous findings from the Southeast European region. We discuss potential indicator values of macroalgae associations, rather than of a single species. [ABSTRACT FROM AUTHOR]

Organic carbon fixed in chloroplasts through the Calvin–Benson–Bassham Cycle can be diverted toward different metabolic fates, including cytoplasmic and mitochondrial respiration, gluconeogenesis, and synthesis of diverse plastid metabolites via the pyruvate hub. In plants, pyruvate is principally produced via cytoplasmic glycolysis, although a plastid-targeted lower glycolytic pathway is known to exist in non-photosynthetic tissue. Here, we characterized a lower plastid glycolysis–gluconeogenesis pathway enabling the direct interconversion of glyceraldehyde-3-phosphate and phospho-enol-pyruvate in diatoms, ecologically important marine algae distantly related to plants. We show that two reversible enzymes required to complete diatom plastid glycolysis–gluconeogenesis, Enolase and bis-phosphoglycerate mutase (PGAM), originated through duplications of mitochondria-targeted respiratory isoforms. Through CRISPR-Cas9 mutagenesis, integrative 'omic analyses, and measured kinetics of expressed enzymes in the diatom Phaeodactylum tricornutum, we present evidence that this pathway diverts plastid glyceraldehyde-3-phosphate into the pyruvate hub, and may also function in the gluconeogenic direction. Considering experimental data, we show that this pathway has different roles dependent in particular on day length and environmental temperature, and show that the cpEnolase and cpPGAM genes are expressed at elevated levels in high-latitude oceans where diatoms are abundant. Our data provide evolutionary, meta-genomic, and functional insights into a poorly understood yet evolutionarily recurrent plastid metabolic pathway. Environmental and experimental methods reveal the importance of plastid-targeted Enolase and bis-phosphoglycerate mutase enzymes to diatoms, marine algae that contribute to global primary production. [ABSTRACT FROM AUTHOR]

Eucheuma cottonii is a valuable marine algae species widely cultivated in Sumenep, Madura. Recent research on the biochemical characterization of various marine algae species has identified active anti-microbial polyphenols and their derivatives, such as flavonoids. These compounds possess anti-inflammatory and anti-microbial properties. Organisms with sufficient levels of polyphenols and flavonoids tend to have an enhanced immunity against bacterial and viral infections. As a result, Eucheuma cottonii has the potential to serve as a natural source for new medicines derived from the marine resources of Madura Island. This study aimed to optimize the use of marine biological resources, specifically Eucheuma cottonii, as the main ingredient for anti-microbial drugs. The research was conducted between May and November 2021 at the Integrated Laboratory of the University of Trunojoyo Madura. The stages of the research included sampling Eucheuma cottonii, extracting its active compounds, and testing the anti-microbial activity against Aeromonas hydrophila. The results showed that the average yield of Eucheuma cottonii extract ranged from 2.978% to 3.296%. The extract demonstrated anti-microbial properties, as evidenced by the formation of inhibition zones in Aeromonas hydrophila colonies. [ABSTRACT FROM AUTHOR]