Marine macroalgae are widely distributed renewable resources that offer substantial economic and environmental benefits. This review comprehensively examines seaweeds from the phyla Chlorophyta, Heterokontophyta, and Rhodophyta, highlighting key advances and persistent challenges. Global seaweed production is highly concentrated: Asia accounts for 97% of the total, with China as the dominant producer. These seaweeds synthesize a diverse array of bioactive compounds, including sulfated polysaccharides, phlorotannins, terpenoids, proteins, peptides, polyunsaturated fatty acids, and pigments. Notably, brown algae represent the richest source of both phlorotannins and polyunsaturated fatty acids. To recover these valuable compounds efficiently, a range of advanced green extraction techniques have been developed, such as enzyme-assisted, microwave-assisted, ultrasound-assisted, and supercritical fluid extraction, along with natural deep eutectic solvents. These methods consistently outperform conventional approaches in terms of yield, extraction time, and environmental sustainability. The isolated compounds exhibit a broad spectrum of validated pharmacological activities, including immunomodulatory, anti-inflammatory, anti-diabetic, neuroprotective, antitumor, and antiviral effects. Consequently, they have found diverse applications in functional foods, biomedicine, cosmetics, agriculture, aquaculture, and environmental protection. Despite this promise, critical challenges remain in elucidating structure-activity relationships, developing scalable and sustainable extraction protocols, and advancing clinical translation. Future research should prioritize the discovery of novel marine bioactives, the enzymatic production of oligosaccharides, efficient purification of algal proteins and peptides, and the scaling-up of industrial processes to fully realize the pharmaceutical and biotechnological potential of marine macroalgae.

Marine-derived products exhibit applicability in the field of biomaterials and medical devices due to their unique physical, chemical, and biological properties including mechanical reinforcement, underwater adhesion, swelling capacity, and biocompatibility. They can support crucial cellular proliferation, migration, and differentiation, being suitable for tissue engineering and wound healing. This review discusses biomaterials and medical devices derived from marine sources by analyzing their natural properties and highlighting advantages of scaffolds, adhesives, and drug delivery systems. We review organisms from the animal phyla Porifera (sponges), Cnidaria (jellyfish, corals), Mollusca (molluscs, octopus), Chordata (fish, sea squirt), algae phylum Chlorophyta (green microalgae), and prokaryotic phylum Cyanobacteria (cyanobacteria). We discuss the need of applying suitable controls and establishing a sustainable scale-up process to assess their promising results and make them available for patients. We also highlight the advantage of implementing biotechnology and waste by-products in their crafting as an opportunity for incorporating biomedicine in a circular economy.

ABSTRACT Against climate changes challenging the terrestrial food production, macroalgae serves as a nutrient rich healthy food with bioactive compounds. Macroalgae can reduce the environmental carbon dioxide through efficient photosynthesis. Populations in the equatorial, eastern, and coastal Europe consumed microalgae for centuries after primary processing. The interest in macroalgae belonging to the three phyla Phaeophyta (brown algae), Rhodophyta (red algae) and Chlorophyta (green algae) as a food source is growing. The species among the three phyla show varying capacities for production of food macronutrients and micronutrients. Many functional food components in macroalgae are associated with the three macronutrients. Macroalgae could be used to produce hybrid processed foods or to substitute for terrestrial plant foods. The food industries and the state organizations need to make concerted efforts to process marine macroalgae. There is a need to shift from the conventional primary processing to secondary processing, generating novel functional foods and ingredients. The existing information on potentially hazardous contaminants or inherent constituents in macroalgae, and the environmental impacts affecting economies, need attention. There is a need to expand on food regulations for macroalgae products, harmonizing them globally. Marketing strategies for novel macroalgal foods indicating their ability to improve metabbolic health of consumers are a necessity.

The biodiversity of seaweed encompasses a wide array of potential bioactive compounds applicable to various industries, particularly pharmaceuticals. This study aimed to collect seaweed diversity data from Panjang Island, Jepara, Central Java, Indonesia, and to identify the bioactive compounds and biological activity of each seaweed species for preliminary screening. Random sampling was used to collect the sample. Qualitative identification of bioactive compounds was performed using the maceration method for extraction, phytochemical screening tests, and pigment identification based on Rf values on TLC. Antibacterial screening tests were performed against Gram-positive (S. aureus) and Gram-negative (E. coli) bacteria, followed by testing against pathogenic fungi (C. albicans) using the disk diffusion method, and an antioxidant test using the DPPH method. The results showed that six species from three phyla (Chlorophyta, Phaeophyta, and Rhodophyta) exhibited distinct morphological characteristics, and the types of bioactive compounds produced by each species differed. The biological activity test results showed a low inhibitory activity. Antibacterial and antifungal biological activities were at the value of (<5 mm), and antioxidant biological activity was (>750 ppm). However, the active compounds and pigments with potential antibacterial, antifungal, and antioxidant properties can be optimized in various fields of bioindustry in the future.

Filamentous opportunistic algae, which behave as opportunistic species, are frequently observed in Eriocheir sinensis aquaculture ponds. These algae can entangle Eriocheir sinensis and release harmful substances during decomposition, thereby negatively impacting farming performance. At present, their management largely depends on non-selective herbicides, while fundamental research on species composition and biomass dynamics remains limited. In this study, 19 aquaculture ponds across five E. sinensis farms in Shanghai were monitored over a two-year period. Filamentous algae species were identified using both morphological and molecular techniques, and their biomass and coverage were quantified. Concurrently, physicochemical parameters of the water were measured to analyze algal occurrence patterns and key environmental drivers. A total of 19 species belonging to four genera of the phyla Chlorophyta and Charophyta were identified. Rhizoclonium was the most common genus, followed by Cladophora and Spirogyra. These genera exhibited distinct seasonal succession, with Cladophora and Spirogyra dominating in spring, while Rhizoclonium predominanted in summer and autumn. Filamentous algal biomass reached its peak in May 2024, with a dry weight of 42.92 g/m2. The two-way ANOVA results indicated significant main effects of month and region, as well as a significant month × region interaction. The Spearman correlation analysis revealed a strong positive association between algal biomass and pH. This pattern is consistent with the effect where the intense algal photosynthesis raises water pH through the uptake of dissolved carbon dioxide. The total biomass was significantly correlated with the nitrogen-to-phosphorus ratio, suggesting that nitrogen and phosphorus availability influenced algal growth. Moreover, filamentous algal coverage was positively associated with maximum algal biomass. The linear regression analysis further revealed that multiple environmental factors jointly contributed to algal proliferation, with total nitrogen, nitrate nitrogen, and fluorescent dissolved organic matter (fDOM) showing relatively strong associations with maximum biomass. These findings provide a scientific basis for the ecological control and targeted management of filamentous algae in aquaculture systems.

Macroalgae are autotrophic organisms that do not have organs like plants, such as roots, stems, and leaves. Macroalgae are grouped based on shape, size, and color. Indonesia is the secondlargest seaweed-producing country in the world. One of the coastal areas with abundant natural resources is the Garut Regency, Indonesia. The coastal area in Garut Regency has an area of around 306,519 Ha with a length of the south coast area of around 72 km. The South Garut Coast area has abundant marine resources, especially macroalgae. There are 44 species of macroalgae of this type consisting of three divisions, namely the Chlorophyta division, which consists of 13 species and seven genera; the Phaeophyta division, consisting of 9 species and four genera; and the Rhodophyta division, consisting of 22 species and ten genera. The macroalgae most commonly found in the coastal waters of South Garut are Glacilaria (six species) and Sargassum (four species). Macroalgae have benefited from an ecological and economic perspective. The chemical content of macroalgae can also be used as raw materials or additional ingredients in several industries, such as the food, supplement, medicine, agriculture, and cosmetics industries. The influence of seasons and variations in harvest will influence the chemical content in macroalgae. Green algae (Chlorophyta) have higher protein than brown algae (Phaeophyta) and red algae (Rhodophyta). Brown algae (Phaeophyta) contain higher levels of minerals and polyphenols. The secondary metabolite content of macroalgae has several pharmacological properties such as antioxidant, antibacterial, anti-inflammatory, and anticancer.

Water pollution remains a persistent threat to freshwater ecosystems globally, particularly in regions experiencing increased anthropogenic pressure. The objective of this paper was to investigate the seasonal variations of physicochemical parameters, phytoplankton community structure, and ecological indices of Mbiokporo Stream, Akwa Ibom State, Nigeria, using appropriate standard methods. BOD was significantly higher in the dry season, 15.36 - 16.97 mg/L, compared to the wet season, 2.07 - 2.13 mg/L. Nitrate levels varied minimally from 3.43 - 3.57 mg/L in the wet season and 3.91 - 4.00 mg/L in the dry season. In contrast, phosphate levels showed significant seasonal variation, with higher levels during the dry season 16.34 - 18.34 mg/L, compared to the wet season 0.15 - 0.21 mg/L. A total of 5,798 phytoplankton individuals belonging to four phyla (Charophyta, Chlorophyta, Cyanobacteria, and Heterokontophyta) were identified across all the stations, with Spirogyra africana dominating in both seasons. Phytoplankton composition showed statistically significant (P ≤ 0.05) correlations with key water quality parameters. Diversity indices indicated moderate pollution, with greater ecological stability in the dry season as reflected by higher Shannon Wiener values and lower dominance indices. This study revealed the impact of anthropogenic activities on Mbiokporo stream and provides essential ecological information to serve as a reference to support the effective management of freshwater ecosystems in Nigeria and West Africa. Moreover, continuous monitoring is crucial to mitigate pollution and protect aquatic biodiversity, especially in the context of increasing anthropogenic pressures and seasonal hydrological changes.

Graesiella emersonii is a green microalga, belonging to the phylum Chlorophyta, with ecological and industrial significance. However, its phylogenetic position and mitogenome structure remain largely unexplored. We analyzed the complete mitogenome of G. emersonii GEGS21. This genome was 35,893 bp in length and contained 43 genes that comprised 13 protein-coding, six ribosomal RNA, and 24 transfer RNA genes. Phylogenetic analysis based on six protein-coding genes placed G. emersonii GEGS21 in a strongly supported clade with Pectinodesmus pectinatus, confirming its affiliation within the order Sphaeropleales. This study will provide valuable insights into the mitogenome architecture of G. emersonii, thereby contributing to further elucidation of green algal phylogeny and organelle genomic evolution.

Abstract Cambrian Burgess Shale‐type fossil Lagerstätten yield abundant and diverse animal fossils preserved with both skeletonized and soft tissues, and hence provide more complete evidence for understanding the rapid diversification of animal phyla in the early Cambrian. However, macroalgae have received less attention despite their abundance and ecological importance for animal evolution. Notably, macroalgae preserved with cellular features have not been recognized in Cambrian fossil Lagerstätten, which hinders the interpretation of their affinities. Here, we report an unbranched, multicellular and filamentous macroalga Chaetomorphium cambria gen. et sp. nov. from the Chengjiang biota, representing the first reported macroalgal species preserved with cellular features from the Cambrian Burgess Shale‐type fossil Lagerstätten. Chaetomorphium is characterized by uniseriate unbranched filaments composed of relatively large cells, filament growth through intercalary cell division, and asexual reproduction through akinetes. Accordingly, Chaetomorphium is assigned to the total‐group of the Cladophorales in the class Ulvophyceae of the phylum Chlorophyta. The new finding demonstrates that early unbranched filamentous cladophoraleans acquired cellular differentiation, and intercalary cell division no later than the early Cambrian.

This work presents the didactic collection of marine macroalgae from the Educators Training Institute of the Federal University of Cariri, in Ceará, composed of 25 Taxonomic Units (UTs) of the phyla Chlorophyta, Heterokontophyta and Rhodophyta. The collection has pedagogical potential by providing a visual, tactile, and investigative approach, promoting content contextualization and interdisciplinarity. It enables active teaching strategies, such as practical classes and species identification, aligned with the National Common Curricular Base. Thus, it stimulates scientific curiosity, critical thinking, and the understanding of marine biodiversity and its ecological importance.

Some bromeliads form a compact rosette that accumulates detritus and water, known as phytotelma. The phytotelma is a lentic ephemeral aquatic environment that forms diverse communities with complex trophic levels. Pseudalcantarea grandis, a saxicolous plant, forms a phytotelma. To understand the importance of P. grandis as a eukaryotic diversity reservoir in arid zones, we collected water samples from 5 plants growing in a dry canyon in Zimapán, Hidalgo, Mexico. We analyzed them through metabarcoding of the ITS1 (Internal Transcribed Spacer) and the partial 5.8S gene. We used the Ion Torrent PGM platform for the sequencing, and the taxonomic assignation for the amplicons was made with BLAST in Genbank at NCBI. We found 26 phyla and 543 genera, 80% of which belonged to Ascomycota, Basidiomycota, Blastocladiomycota Chytridiomycota, Glomeromycota, Mucoromycota, and Zoopagomycota phyla. The remaining 20% was composed of 19 phyla belonging to other kingdoms. Photosynthetic organisms were represented by the phyla Bacillariophyta, Charophyta, Chlorophyta, and Ochrophyta. The vascular plants do not live in the tank but constitute the debris sustaining the large number of decomposers. The trophic levels in the tank were detritus, micro- and macro-decomposers, filter feeders, photosynthesizers, micro-predators, aquatic volume predators, surface predators, and parasites.

Microalgae are promising candidates for sustainable bioprocesses owing to their ability to capture/utilize CO2 and produce valuable metabolites. However, strain-to-strain variability poses a challenge to industrial scalability. This paper reports a study on the screening of 28 Chlorophyta microalgal strains from six species cultivated under standardized semi-continuous conditions in a bubble column bioreactor. Growth kinetics, nitrogen uptake, and metabolite accumulation were analyzed to identify strains characterized by promising biomass/metabolite productivities. The results indicated two distinct kinetic behaviors: a large fraction of the investigated strains was characterized by a common biomass/nitrate uptake behavior, and a subset of the strain pool was characterized by atypical nitrogen assimilation patterns. Strains characterized by high biomass growth rates are characterized by high lipid productivity. Strains with intermediate biomass growth rates are characterized by high carbohydrate accumulation. Chlorella vulgaris (ACUF 058) and Chloroidium saccharophilum (ACUF 050) emerged as strong candidates for carbohydrate and protein production, respectively. This study proposed a systematic procedure for strain selection, bridging laboratory screening, and industrial feasibility. These results emphasize the role of tailored cultivation strategies in optimizing biomass yield and metabolite productivity. Further research integrating genomic and proteomic insights will enhance strain-specific process optimization, facilitating the large-scale deployment of microalgal bioprocesses.

Research on analysis of macroalgae community structure on different substrates in Sabang waters to identify, analyzing diversity, abundance, and important value index. The data collection method was carried out by purposive sampling using a plot of 1x1 m2 with 10 plots per transect. Sampling was carried out at three stations, namely Station I on Pasir Putih with a medium fine sand substrate, Station II at Anoi Itam with a gravel sand substrate, and Station III on Rubiah Island with a fine sandy clay substrate. Data were analyzed using the Importance Value Index (IVI) and the Shannon-Wiener Diversity Index. The environmental parameters at each station that were measured were substrate particles, temperature, brightness, depth, and current velocity, while the chemical parameters were salinity, pH, COD, phosphate, and nitrate. The results of the study found 2615 macroalgae individuals consisting of three divisions. Chlorophyta division consists of 9 species, Rhodophyta was 7 species, and Phaeophyta was 1 species (Dyctyota dichotoma). The highest Important Value Index at each research station consisted of the Chlorophyta division with two species, namely Dictyosphaeria cavernosa (IVI = 59.18) and Halimeda opuntia (IVI = 54.15). The value of the diversity index (H') of macroalgae in Sabang waters is moderate, namely in Pasir Putih as much as 2.18, Anoi Itam and Rubiah Island as much as 2.01, and 1.97, respectively. The study concluded that the macroalgae community structure in Sabang waters exhibits moderate species diversity, with the Chlorophyta division, particularly Dictyosphaeria cavernosa and Halimeda opuntia, showing the highest importance value indices across different substrates.

This study was conducted to investigate the plankton diversity and physico-chemical characteristics of River Ose in providing information that can be used for proper management and conservation of the water body. Plankton samples and water quality parameter were observed for 12 months (February, 2022 to January, 2023). Plankton abundance was estimated using Shannon-wiener diversity index (H). Physico-chemical parameters which include: pH, Temperature, Conductivity, Dissolved Oxygen, Salinity and Total Dissolved Solid were determined insitu using a multi-parameter probe meter. The species composition of phytoplankton was dominated by five phyla, Bacillariophyta, Chlorophyta, Cyanobacteria, Ochrophyta, and, Myzozoa while that of zooplankton were the Arthropod, Ciliophora and Rotifera groups. Spirogyra sp. which belongs to the phylum Chlorophyta had the highest relative abundance (8.31%) while Thalassionema sp. which belong to phylum Ochrophyta had the lowest relative abundance (0.83%). Higher abundance of plankton was recorded during the dry season (61.13%) when compared with the raining season (38.38%). Shannon-Wiener diversity index (H) and Evenness (E) were 3.25 and 0.93 respectively. The results of the physicochemical parameters were within the acceptable range across the 12 months of study.

New data have been obtained on the taxonomic composition of algae and cyanobacteria in the water bodies of the Olyokma Nature Reserve. In two surveyed oxbow lakes, 119 species and varieties of algae were identifi ed. Previously published data on the algal fl ora of the reserve were analyzed. Based on this, a consolidated taxonomic list of algae and cyanobacteria was compiled, comprising 418 taxa, 89 of which are new records for the reserve. In terms of species richness, representatives of the phylum Heterokontophyta predominate. They are followed, respectively, by the phyla Charophyta and Chlorophyta in terms of species diversity. Desmid algae are the most diverse at the levels of orders, families, and genera. Overall, the algal fl ora of the reserve is signifi cantly richer compared to the surrounding areas. The most promising directions for continuing algological research in the reserve have been identifi ed.

Bryophytes establish a wide variety of associations with other organisms, including microalgae. Although this type of relationship is widely distributed and has been the subject of numerous studies, it is not yet well understood in the Canary Islands. This study focuses on the diversity of microalgae associated with the foliose liverwort Porella canariensis, growing epiphytically on Laurus novocanariensis in laurel forests. The composition of microalgae has been analyzed by applying specific enrichment techniques on fragments of the liverwort collected at different heights on the trunk, as well as from different parts of the gametophyte. As a result, a catalog of 14 genera belonging to the phyla Bacillariophyta, Chlorophyta, and Cyanobacteria is presented. The analysis of the results revealed that there are no significant differences in the diversity of microalgae depending on the height at which the liverwort grows on the trunk or its position in the gametophyte.

Freshwater reservoirs serve as vital water sources for numerous residential areas. However, the excessive presence of nutrients, such as nitrogen and phosphorus, stimulates rapid algal proliferation, leading to the occurrence of algal blooms. To prevent this phenomenon, it is imperative to conduct regular ecological surveys aimed at assessing water quality and monitoring the dynamic composition of aquatic biological communities within the reservoir’s ecosystem. In this study, seasonal changes in water quality parameters and the spatial and temporal distribution of planktonic algae at 14 sampling sites in the Danjiangkou reservoir were analyzed. A total of 136 taxonomic units of planktonic algae were identified, belonging to 8 phyla, 41 families, and 88 genera, with the dominant algae belonging to the phyla Chlorophyta, Bacillariophyta, and Cyanophyta. The order of abundance of the algae was summer > autumn > spring > winter and Hanku > Intake > Danku > Outflow. WT, pH, DO, CODMn, and Chl a were the primary drivers influencing the changes in the planktonic algal community within the reservoir. Two dominant algae, Chlamydomonas debaryana and Scenedesmus quadricauda, were isolated and cultured indoors to simulate the growth behaviors of algae in the Danjiangkou reservoir. The results show that the growth of C. debaryana was severely limited by the temperature, light, and nutrient concentration, whereas the growth of S. quadricauda was slightly affected under different temperature and light conditions and could occur at low concentrations of nitrogen and phosphorus nutrients. With excess nutrient levels, excessive proliferation of S. quadricauda could potentially cause algal blooms. This study examined the growth characteristics of the dominant algae in the Danjiangkou reservoir under laboratory conditions and delved into their interdependencies with environmental factors, aiming to furnish a theoretical and experimental foundation for investigating algal community dynamics and preventing algal blooms within the freshwater reservoir.

This study was conducted to determine macroalgae-invertebrate associations in Santa Maria, Ilocos Sur, Philippines: ecological survey and community-based economic utility. Specifically, it determined the macroalgal species in both the intertidal and subtidal zones in terms of percent cover, associated invertebrates and their type of association, and community-based economic utility. The study employed a descriptive and observational method, utilizing transect-quadrat sampling. The study protocol was approved by the University Research Ethics Committee. Results show that Division Rhodophyta (red algae) had the highest percent cover for both the intertidal and subtidal zones, followed by Division Chlorophyta (green algae) and Division Phaeophyta (brown algae) respectively. Ecological associations between the macroalgae and invertebrate species range from commensalism, herbivory, facilitative, indirect mutualism, and predatory. Community-based economic utility for the macroalgae and associated invertebrates include the following: livelihood and income generation, local food consumption and market sales, small-scale aquaculture activities, raw materials for food products, souvenirs, or processed goods. These activities help sustain coastal community livelihoods and contribute to local economic development of the community.  It is recommended that community-based coastal resource management (CBCRM) programs involving LGUs, academic institutions, NGOs and fisherfolks may be implemented to promote awareness, conservation, and sustainable use of resources, to sustain the economic, ecological, and social value of macroalgae and associated invertebrates in the community.

The study of the Caspian Sea's algal flora started in the 1960s.However, over the past 20 years, there has been a significant gap in the study of the algal flora in the Azerbaijani part of the sea.As a result, it is now crucial to expand these studies and compare the obtained data with the previous results.The algal flora of the Caspian Sea has been poorly studied taxonomically.The main goal of our research was to identify the biodiversity of the algae of the Caspian Sea, to examine its taxonomic structure and to determine the influence of some external environmental factors.The article contains new information on the marine macrophytes and microscopic algal flora of the coastal zones of the Absheron Peninsula.During our research, 26 species of algae were identified.Species belong to divisions Rhodophyta (1 species), Charophyta (3 species), Cyanobacteria (3 species), Chlorophyta (10 species) and Bacillariophytina (subphylum) (9 species).Chlorophyta division was the dominant group, constituting 38.5% of algal flora, followed by Cyanobacteria -11.5%, Charophyta -11.5%, Rhodophyta -3.9% Bacillariophytina -34.6%, Bacillariophytina -34.6%.The leading families of the algal flora were Oscillatoriaceae Engler, Spirogyraceae Bessey, Cladophoraceae Wille and Naviculaceae Ktzing.

Macroalgae are multicellular lower plant organisms that live in water, especially in marine waters. Macroalgae better known as marine algae are macroscopic algae that can reach several meters in length. Macroalgae are a highly diverse group of organisms in terms of morphology, level of structural complexity, and size. They play an important role in maintaining ocean water quality, reducing coastal erosion, and providing habitat for a wide variety of marine life. This study aimed to identify the macroalgae species present in the Sire Beach area and determine the ecological index of macroalgae in the Sire Beach area. This study was conducted from October to December 2024. Data collection was carried out using the transect method along the coastline with a transect size of 50 m perpendicular to the coastline. The macroalgae data found in this study are categorized into three classes, seven orders, seven families, nine genera, and 15 species of macroalgae. The macroalgae types found include eight species of the phylum Chlorophyta, four species of the phylum Phaeophyta, and three species of the phylum Rhodophyta. Chlorophyta (green algae) is the most common type of macroalgae in Shira Beach. The diversity index (H\') in this study was 2.47, indicating a moderate diversity of macroalgae. The evenness index value obtained is 0.91 which indicates that the evenness value is high. The dominance index in this study is 0.11 which indicates that the level of dominance is low. The obtained Margarev's wealth indicator is 3.69, indicating that the richness of the seeds is moderate.