Search Results (200)

Floating seaweeds can be an effective dispersal vector for non-buoyant seaweeds. An under-explored aspect is the examination of seaweed rafts and their non-buoyant seaweed community after the floating journey ends. In this study, we analyzed 476 entire stranded specimens of the floating seaweed Durvillaea incurvata and their associated epiphytes, which were collected during winters and summers of 2023–2025 at four sites along the continental coast of Chile (between 31° S and 41° S). A total of 57 species of epiphytic seaweeds were found, with a higher predominance of Rhodophyta (71.9%). The most representative morpho-functional group was coarsely branched (29.1%). The species Lessonia spicata, Antithamnionella ternifolia, Corallina chilensis, Gelidium rex, G. chilense, and G. lingulatum were found frequently, and 67% of all epiphyte specimens found were reproductive. A higher taxonomic richness of epiphytes was observed at the southern-central sites compared to the northern site, being higher in summer than in winter. These results confirm that epiphytes associated with floating seaweeds are common and that many of these have reproductive structures. Co-occurrence analysis suggests that interactions among morpho-functional groups of epiphytes facilitate long-distance dispersal events. Future studies should assess the physiological viability and ability to reproduce of epiphytes after extensive floating journeys. This would contribute to understanding the effectiveness of rafting dispersal by floating seaweeds on the connectivity of raft-associated algal populations. Full article

Macroalgal species are widely distributed throughout the world’s oceans and are well recognised for their biotechnological, ecological, and pharmacological potentials, containing a wide range of diverse bioactive compounds. In many coastal habitats worldwide, excessive accumulations of algal biomass (including rapidly growing blooms and drift accumulations resulting from dislodgement from benthic habitats) are commonplace and can pose environmental and economic challenges. In this study, we report occurrences of algal blooms and drift accumulations during 2024 and 2025 involving three major macroalgal clades, Chlorophyta, Phaeophyceae, and Rhodophyta, from two distinct marine regions: the North Atlantic Ocean and the South Pacific Ocean. Species identified included Grateloupia turuturu, Polyides rotundus, Ascophyllum nodosum, Ulva spp., Sargassum spp. and Fucus spp., among others. The indicated species are known for their diverse pharmacological properties, including antimicrobial, antioxidant, and anti-inflammatory effects. Specialised bioinformatic tools were employed to assess the potential of identified macroalgae as a source of antimicrobial peptides (AMPs). For selected macroalgal species, in silico screening of publicly available databases was performed to identify previously reported and characterised AMPs associated with these species. This in silico approach presents a promising strategy for discovering novel antimicrobial agents with potential activity, especially against drug-resistant bacteria. Finally, applying proteomics methodologies for in silico evaluation of the selected algal species advances modern technologies for the sustainable use of natural resources. Full article

Gracilaria edulis, a red seaweed that is widely known as an agar-producing seaweed, has a unique biosynthetic pathway for producing bioactive compounds. However, most of the bioactive compounds of this species have not explored yet. The environmental conditions as well as the extraction method might influence the bioactive compound production. Hence, this study aimed to explore untargeted liquid chromatography–high resolution mass spectrometry (LCHRMS)-based metabolomics profiling of G. edulis (Gracilariales, Rhodophyta) from three different beaches along the southern part of the Special Region of Yogyakarta (Java Island, Indonesia), which has different environmental characteristics. We also observed the effect of extraction solvent on metabolomic profiling of G. edulis extract using three different solvents with the different polarity. Metabolomic profiling was performed using an LC-HRMS instrument and analyzed using the Global Natural Product Social Molecular Networking (GNPS) database. The results revealed differences in the metabolomic profiles of G. edulis’s extracts based on coastal location and solvent. G. edulis from Kukup Beach exhibited the highest metabolomic diversity (277 nodes), followed by G. edulis from Sepanjang Beach (268) and G. edulis from Krakal Beach (204). Among the solvents, n-hexane was the most effective, extracting 311 nodes, followed by methanol (293) and ethyl acetate (197). Nine tentatively dereplicated compounds were found, i.e., pumilacidine C, pumilacidine E, lichenysin, cholesterol, AC1L1X1Z, sarmentoside B, 7-dehydrocholesterol, pheophytin A and porphyra-334. Some dereplicated compounds were found in a specific area. For example, lichenysin and pumilacidin compounds were produced by G. edulis from Sepanjang Beach, while cholesterol and AC1L1X1Z were found in from G. edulis extract, which were collected from Sepanjang and Kukup Beaches, and 7-dehydrocholesterol and sarmentoside B compounds from all beach locations, while pheophytin A and porphyra-334 from Krakal Beach. Further research is needed to obtain pure compounds that have the potential to be antibacterial, as well as antioxidant, anti-inflammatory, and photoprotective compounds. Full article

To address the increasing global demand for eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), novel and sustainable sources are required. Seaweeds have been identified as promising alternative sources of these fatty acids (FAs). This study evaluated the FA profiles of dry, commercially available seaweeds in the United Kingdom, including Porphyra spp., Palmaria palmata, Himanthalia elongata, Laminaria digitata, Saccharina japonica, Undaria pinnatifida, Sargassum fusiforme and Fucus vesiculosus. FA identification was performed by gas chromatography. The highest content of polyunsaturated FAs (PUFAs) was observed in U. pinnatifida, accounting for 67.68% of the total FAs (TFAs). EPA represented 33.34% of TFA content in Rhodophyta and 7.13% in Ochrophyta. EPA was the dominant FA in Porphyra spp., comprising 38.91% of TFAs (1064.40 mg/100 g dry weight). A higher content of EPA was also found in P. palmata (32.18%), L. digitata (13.76%), and U. pinnatifida (13.00%). DHA content was consistently lower than that of EPA, with the highest proportion observed in P. palmata (0.27% of TFAs). U. pinnatifida, P. palmata and Porphyra spp. appear to be the most promising seaweed species for providing n-3 long-chain PUFAs in human diets. Full article

Intraspecific variation in mitogenomes has provided the resolution to distinguish between morphologically indistinguishable species and highlight cryptic speciation. This level of variation is underexplored in introduced marine algae. This study evaluated the mitogenomic variability of Gracilaria vermiculophylla, one of the most invasive red algae in the Northern Hemisphere. Nine mitogenomes, comprising seven newly generated complete mitogenomes from Korea, Japan, and Morocco, plus two publicly available mitogenomes, were included in our analysis. The mitogenomes were highly conserved, ranged from 26,064 to 26,178 bp in length, and contained 52 genes comprising 25 protein-coding genes, three rRNAs, and 24 tRNAs. Nucleotide composition showed a strong AT bias (71.6%), with AT skew and GC skew values of 0.050 and 0.014–0.021, respectively. Pairwise divergences of cox2, rnl and rns rRNA were remarkably low, in a range of 0–0.06%, suggesting alternate markers for determining recent introductions. The phylogenetic relationship based on protein-coding genes revealed three shallow groups in G. vermiculophylla, which were correlated with distribution: two C groups from warm temperate sites and one T group from cold temperate sites. This result highlights mitogenomics as a new tool for the deeper understanding of phylogeography and invasion genetics of marine red algae. Full article

Ghost nets are the result of fishing nets ending up at sea by fishing vessels during operations, repairs, accidental loss, and from aquaculture activities. This is a major threat to the marine environment due to the entrapment of marine species, which often leads to the mortality of important species, the alteration of the marine benthic habitat, and the release of microplastics. In the current study, the authors conducted underwater clean-up activities in the marine protected area of Sounio in Greece (NATURA2000) to identify, evaluate whether they can be removed, and remove ghost nets. A total of 1200 Kg of ghost nets was removed within one year, with 68 different species reported to have colonized the nets. The reported groups were Mollusca, Porifera, Chordata, Arthropoda, Echinodermata, Bryozoa, Ochrophyta, Tracheophyta, Rhodophyta, Cnidaria, Chlorophyta, and Annelida. The species were not listed as threatened by the IUCN conservation status, while 86% were native, and 14% were invasive in the Mediterranean Sea. The current work presents the need to expand research efforts in the field of underwater plastic pollution, implement monitoring campaigns to a greater extent in the study area, and perform an assessment before the removal of ghost nets. Full article

GC-MS oxylipin profiling of brown and red algal thalli was performed. Brown algae (Fucus distichus and Alaria esculenta) were collected from the Barents Sea coastline nearby Teriberka, Murmansk region, Kola Peninsula, Russia, while other brown and red algae were sourced from the Pacific coast of the Russian Far East. Triols and δ-ketols (epoxyalcohol synthase products) were found in most brown and red algae. Several Heterokontophyta and Rhodophyta species possessed α-ketols (products of allene oxide synthase) and related vic-diols. Plasmodiophorols and ectocarpins (hydroperoxide bicyclase (HPB) products) were found only in brown algae from the Ectocarpales, Fucales, and Laminariales orders, not in brown algae from the Desmarestiales or Dictyotales orders, or in any red algae. Therefore, plasmodiophorol A and other HPB products could be used as chemotaxonomic markers for the classification of the separate orders of algae within Heterokontophyta. The in vitro incubations of F. distichus thalli with linoleic and α-linolenic acid resulted in the formation of α-ketols and the hydroperoxide bicyclase product, plasmodiophorol A. Full article

Macroalgae provide key ecosystem services, forming habitats such as kelp and fucoid forests, rhodolith beds, and coralline reefs that sustain high biodiversity. However, multiple stressors, including climate change, harmful fishery practices, and pollution and coastal urbanization are driving macroalgal diversity loss and changing species composition and abundance. This study aims to assess macroalgal representativeness, richness and endemism in 16 Marine Protected Areas (MPAs), including four oceanic islands, and test if macroalgal assemblages in MPAs are distributed along a latitudinal gradient (0–29° S) in the Southwest Atlantic. To investigate the processes underlying community patterns, β-diversity was decomposition turnover and nestedness components. The complexity of taxonomic structure was measured by taxonomic distinctness. Overall, the studied MPAs comprised 695 macroalgal taxa, about 69% of Brazilian taxa, and 36% of the endemics. Rhodophyta were dominant (449 species) in most studied areas, except at Trindade and Martim Vaz Archipelago MPA, followed by Chlorophyta (158 species) and Ochrophyta (88 species). Macroalgal species composition in MPAs varied with latitude, and not with area size. They were continuously distributed across northeastern, eastern and southeastern Brazil and oceanic island ecoregions, between Fernando de Noronha (3° S) and São Paulo Litoral Norte (23° S) MPAs. Macroalgal diversity dissimilarity among MPAs was 92%, dominated by the turnover component (88%) and nestedness as a minor component (4%), indicating that dissimilarities are mainly driven by the replacement of species, rather than a gradual loss or gain of species. Effective protection of these MPAs should be prioritized as they harbor highly diverse, unique, and heterogeneous macroalgal assemblages along the SWA, surrounded by heavily impacted areas. Assessment of human impacts on macroalgal habitats in MPAs would contribute to defining effective management actions. Mid- and offshore shelf macroalgal habitats, particularly rhodolith beds, which harbor rare kelp species and mesophotic reefs, remain underprotected, and should be integrated into marine spatial planning for biodiversity conservation. Full article

The Portuguese Atlantic continental coast serves as a biogeographic transition zone where numerous macroalgal species reach their distribution limits, making it an especially intriguing area for studying shifts in species distribution. This region features sandy beaches and rocky outcrops that serve as habitats for a diverse range of organisms, including macroalgae. This illustrated guide aims to provide a simple and accessible overview of some of the most representative macroalgae species found along this coastline, specifically those designed for non-specialists in seaweed identification. Rather than offering a detailed identification key, the guide introduces key aspects of macroalgae—such as pigment composition, taxonomic classification, morphology, branching types, habitat on rocky shores, and potential human uses—in a clear and approachable format. Each species is accompanied by a photographic image, a general morphological description, and information about its typical habitat. Additionally, icons indicate whether a species has potential human applications or is considered non-indigenous. Species are categorized into green, brown, or red macroalgae based on their color and morphological characteristics. Full article

Transcription factors (TFs) are important gene transcription regulators involved in myriad functions such as development, metabolism, and stress response. TFs are found in all eukaryotes, with many families of TFs unique to plants and algae. Algae are of interest due to a wide range of novel metabolites, of which TFs play an important role in regulating their biosynthesis. In particular, the red algae (phylum Rhodophyta) are a source of several important metabolites that are a current focus of further research. However, to date, investigations of TF families in rhodophytes have been limited due to the relative lack of genomic resources available and the small number of in silico analyses of their TFs. In this study, we used genomic and transcriptomic data to identify rhodophyte TFs. We found that the general proportion of TFs in rhodophytes was overall consistent with previous research. However, for the first time in the rhodophyte class Florideophyceae, we report the presence of a putative TF within the trihelix TF (TTF) family, which are light-sensitive TFs associated with growth and stress response. In particular, we demonstrate evidence suggesting the presence of putative TTFs in three Asparagopsis taxiformis genomes, as well as in several other florideophyte assemblies. This was supported by analyses including Neighbour-Joining phylogeny, protein structure prediction, and motif analysis. In summary, this research reported the repertoire of TFs in rhodophyte algae across a much greater range than previously reported and identified putative TTFs in several algae from the class Florideophyceae. This opens an avenue for further research into the evolution of various TFs in early plants, as well as key regulatory factors in rhodophyte metabolism, though future research, such as functional characterisation, will be required to confirm these findings. Full article

Taxonomic clarity within the genus Antithamnion is critical for understanding its molecular phylogeny and biodiversity. Here we report Antithamnion hubbsii for the first time from the Korean coast. This finding highlights the need to re-evaluate its relationship with the previously reported, morphologically very similar A. nipponicum in this region, raising the question of whether the newly identified A. hubbsii represents a local variant of A. nipponicum or a recently introduced invasive species via nearby ports. Specimens collected from Gangneung were analyzed using plastid-encoded rbcL and psaA genes, confirming their identity as A. hubbsii. Morphological features such as indeterminate lateral axes, oppositely arranged pinnae and pinnules, and distinctive adaxial gland cells supported this identification. Molecular analyses revealed minimal divergence between A. hubbsii and A. nipponicum (1–3 bp in rbcL, none in psbA), and contrasting results from different species delimitation methods. Phylogenetic analyses nevertheless placed the Korean specimens in a strongly supported A. hubbsii/A. nipponicum clade. Taken together, our results suggest that the North American invasive A. nipponicum and the Korean A. hubbsii may represent a single species with broad intraspecific variation. Definitive resolution will require molecular analyses of the type specimens of both taxa. Full article

Rhodomelaceae is the largest red algae family, with 158 genera and more than 1000 described nominal species. In particular, Acanthophora (Rhodomelaceae) is a red alga with erect thalli that arises from stoloniferous branches or holdfast discs, with cylindrical main axes and spine-like branchlets. The life cycle of members of this genus has been partially described; however, the female gamete (carpogonium) has not been described. Here, we present a complete description of each stage in the life cycle of Acanthophora. Thalli of this species were collected from 27 localities in the Gulf of Mexico between 2021 and 2024 and placed in a 5% formaldehyde solution in seawater. Reproductive structures were measured and characterized under stereo and optical microscopes. A total of 62 thalli were collected, of which 10 were carposporophytes, 12 male gametophytes, 1 female gametophyte, 16 vegetative thalli, and 23 tetrasporophytic thalli. A detailed description of the shape and size of the reproductive structures is presented. We documented carpogonium for the first time. The evidence here presented contributes to the description of the life cycle of the genus Acanthophora, in which structures forgotten in current works are recovered, which is of great help in the comparative phycology of the Rhodomelaceae family and Ceramiales order. Full article

Over the past twenty years, significant efforts have been made to digitize natural collections. This process represents a crucial step in preserving and enhancing biodiversity data. In this context, the phycology team from the Institute for Water Research (CNR-IRSA) in Taranto (southern Italy), as a partner of the NRRP Project ITINERIS, and within the nascent European Research Infrastructure “Distributed System of Scientific Collections” (DiSSCo), answered to the challenge of digitizing and sharing the extensive biodiversity data preserved in the marine macrophyte collection Herbarium TAR. This herbarium includes over 500 species collected between 1982 and 2025. Digitization was carried out in accordance with international standards for imaging and in compliance with FAIR principles for metadata curation. A total of 353 digital specimens were produced, including 152 species of seaweeds (76 Rhodophyta, 47 Heterokontophyta, and 29 Chlorophyta) and 3 species of Spermatophyta. Notably, 15 non-indigenous species were documented. Part of the metadata, structured using the Darwin Core standard, has been published on GBIF. This initiative, carried out within the ITINERIS framework, highlights the value of both long-term biodiversity monitoring and digital data in supporting research on climate change, biological invasions, and the conservation of marine ecosystems. Full article

Marine macroalgae, classified into three major groups, brown (Phaeophyceae), red (Rhodophyta), and green (Chlorophyta), represent a source of structurally diverse compounds relevant for topical applications. This narrative review of the peer-reviewed literature and regulatory databases targets macroalgae-derived active ingredients in cosmetic formulations and in wound-healing applications. It outlines major compound classes (polyphenols, sulfated polysaccharides, carotenoids, fatty acids, and peptides), along with their documented biological effects on skin (antioxidant, anti-inflammatory, moisturizing, photoprotective, and anti-aging activity) and regulatory/safety aspects with formulation strategies. This review also addresses the variability in compound concentrations resulting from species, environmental conditions, and seasonal factors, which impacts reproducibility and standardization. Common extraction techniques like solvent extraction, ultrasound-assisted extraction, supercritical fluid extraction, and enzyme-assisted methods are described in relation to compound class and yield. Analytical methods used for the identification and quantification of these compounds, including HPLC, GC-MS, and FTIR, are then summarized. Additionally, recent in vitro and in vivo studies evaluating the bioactivity and safety of macroalgae-derived ingredients are discussed. This review compiles relevant evidence to inform formulation strategies and ingredient evaluation in the context of marine-based topical products. Full article

Earth hosts a remarkable diversity of life, with oceans covering over 70% of its surface and supporting the greatest abundance and variety of species, including a vast range of seaweeds. Among these, red seaweeds (Rhodophyta) represent the most diverse group and are particularly rich in bioactive compounds. Grateloupia turuturu Yamada and Porphyra umbilicalis Kütz. are two species with significant biotechnological and functional food potential. They contain high levels of phycobiliproteins, sulfated polysaccharides (e.g., carrageenan, agar, porphyran), mycosporine-like amino acids (MAAs), phenols, minerals, and vitamins, including vitamin B12 (rare among non-animal sources). Several analytical methods, such as spectrophotometry, chromatography, and mass spectrometry, have been used to characterize their chemical composition. In vitro and in vivo studies have demonstrated their antioxidant, anti-inflammatory, neuroprotective, immunostimulatory, anti-proliferative, and photoprotective effects. These bioactive properties support its application in the food, pharmaceutical, and cosmetic sectors. Given the growing demand for sustainable resources, these algae species stand out as promising candidates for aquaculture and the development of functional ingredients. Their incorporation into novel food products, such as snacks and fortified dairy and meat products, underscores their potential to support health-promoting diets. This review highlights G. turuturu and P. umbilicalis chemical richness, bioactivities, and applications, reinforcing their value as sustainable marine resources. Full article