Search Results (316)

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

This study aimed to examine the distribution characteristics of phytoplankton communities in typical lakes in Inner Mongolia and their relationships with environmental factors, focusing on the effects of key factors such as nutrient levels, salinity, and water temperature on phytoplankton community structure. Using multivariate statistical analysis, the community composition, dominant taxa, and their interactions with environmental factors were analyzed across 79 sampling sites distributed among 20 lakes in these six regions. The results indicated significant differences in community structure along a nutrient gradient: Cyanobacteria predominated in eutrophic lakes, whereas Chlorophyta and Bacillariophyta were more common in saline lakes. Nutrient concentrations, particularly total nitrogen and phosphorus, were the main drivers of phytoplankton community changes, leading to frequent cyanobacterial blooms in eutrophic lakes. Salinity significantly regulated phytoplankton diversity, especially in arid and semi-arid regions. Lake eutrophication and phytoplankton proliferation not only altered the community structure but also affected ecosystem stability and function. Certain integrated management strategies, including pollution control, water allocation, and ecological restoration, can effectively mitigate eutrophication-related ecological issues. This study provides essential scientific insights into lake ecological management. Full article

The present study provides an exhaustive exploration of twelve macroalgal species from the Adriatic Sea, including seven brown algae (Ericaria amentacea, Fucus virsoides, Cutleria multifida, Cystoseira compressa, Cystoseira corniculata, Gongolaria barbata and Padina pavonica), three green algae (Codium adhaerens, Codium vermilara and Ulva lactuca), and two red algae (Scinaia furcellata and Asparagopsis taxiformis). Matrix solid-phase dispersion (MSPD) was applied as the extraction technique, using generally recognized as safe (GRAS) solvents. The bioactive profile of the extracts was assessed through the quantification of total phenolic content (TPC) and antioxidant activity. Among the three phyla, U. lactuca, F. virsoides and S. furcellata exhibited the highest TPC (0.8, 26 and 3.0 mgGAE·g⁻¹) and antioxidant activity (1.9, 38 and 7.5 mgTE·g⁻¹), respectively. Targeted HPLC-MS/MS analysis enabled the identification of nineteen phenolic compounds across all taxa. Chlorophyta showed a characteristic profile enriched in coumarins, benzaldehydes and flavanones, including the selective detection of 7-hydroxycoumarin in species with higher antioxidant potential. Additionally, compounds such as chlorogenic, rosmarinic and caffeic acids exhibited taxon-specific distributions that may explain differences in antioxidant activity. Complementary untargeted ultra-high performance liquid chromatography quadrupole time-of-flight (UHPLC-QToF) metabolomics analysis provided broader coverage, revealing eighty metabolites spanning phenolics, sugars, organic acids, lipids, amino acids and their derivatives. Notably, the proposed detection of fatty acid esters of hydroxy fatty acids (FAHFAs) represents the first report of these compounds in macroalgae, alongside a pronounced presence of sulphated phenolics. Overall, these findings provide a robust baseline on the bioactivity and chemical composition of Adriatic macroalgae, highlighting their value as a natural source of functional compounds. Full article

Dongping Lake is a regulating lake where hydrodynamic alteration and heterogeneous inputs may reshape phytoplankton communities; this study aimed to characterize eukaryotic phytoplankton, assess water quality and identify key environmental drivers. In September 2025, eukaryotic phytoplankton were profiled using 18S rDNA V9 eDNA metabarcoding across 18 sites, and community–environment relationships were evaluated using diversity indices, principal coordinates analysis (PCoA), Spearman correlations and redundancy analysis (RDA). This study detected 101 eukaryotic phytoplankton species. Bacillariophyta dominated read abundance at 55.08%, followed by Cryptophyta at 22.20%, whereas species richness was highest in Chlorophyta with 40 species. Site richness ranged from 26 to 63, peaking at sampling sites D17 and D18 and reaching a minimum at sampling site D15; Cryptophyta dominated reads only at sampling site D6. Nine dominant species were identified. Mean diversity values were Shannon-Wiener diversity index (H) 3.45, Pielou evenness index (J) 0.92, Margalef richness index (D) 4.40 and Chao1 richness estimator 44.72, and overall water quality was assessed as slightly polluted, with sampling site D12 or D15 reaching moderate pollution under specific indices. Dominant-species responses were differentiated; for example, Stephanodiscus hantzschii was negatively correlated with NH₄⁺ and TN, and Ceratium hirundinella was positively correlated with salinity but negatively correlated with NH₄⁺. RDA ranked key drivers as salinity > NO₂⁻ > TN > NH₄⁺ > TP > DO > temperature. Salinity and nitrogen-form gradients were closely associated with spatial community differentiation and dominant-species shifts, supporting targeted monitoring and management. Full article

Soil degradation poses a serious threat to the sustainability of global agricultural development, endangering the foundation and environment of human survival. Therefore, elucidating the effects of different agricultural production patterns on the quality and health of paddy soils is of great significance. To investigate the impact of the integrated rice-red swamp crayfish farming on paddy soil health, this paper systematically analyzed the differences in 19 soil physicochemical indicators and bacterial and eukaryotic microbial communities between the traditional rice monoculture (TRM) and integrated rice-red swamp crayfish (Procambarus clarkii) farming (IRPF), and it features a comprehensive quantitative assessment of paddy soil health status through Principal Component Analysis based on a minimum dataset. The experimental results showed that IRPF significantly increased the soil aggregate mean weight diameter, total phosphorus, available potassium, cation exchange capacity, pH, available zinc, and available silicon contents. Meanwhile, IRPF exerted marked effects on the beta diversity and composition of both bacterial and eukaryotic microbial communities, markedly enhancing the relative abundances of Bacillariophyta and Chlorophyta in the paddy soil. The integrated analysis of 19 soil physicochemical indicators along with bacterial and eukaryotic microbial community parameters revealed that the Soil Health Index under IRPF was obviously higher than that under the rice monoculture. In conclusion, the integrated rice-red swamp crayfish farming system markedly impacted the soil fertility, effectively improved soil aggregate structure and enhanced the overall paddy soil health status, representing a promising and sustainable agricultural production pattern within a single production cycle. Full article

The present study investigated the community composition and dynamics of freshwater biofouling on fiberglass inland waterway vessel (IWV) models coated with two commercial antifouling paints deployed in the Danube River (Serbia) for a total of five months. Biofouling was characterized using visual observations, in situ optical microscopy, the rapid ATP bioluminescence method, dry biomass measurements, and analyses of phototrophic and fungal communities. Based on the results, Hard Racing TecCel demonstrated the highest suppression of biofouling, with the lowest biomass accumulation and reduced algal diversity. At all stages of biofouling, diatoms dominated the phototrophic community, comprising 123 taxa. Achnanthidium minutissimum and Gomphonella olivacea were shown to be persistent hull colonizers, while Cyanobacteriophyta and Chlorophyta had reduced presence. Overall, the results highlight a slower progression of freshwater biofouling compared to marine systems and emphasize the need for the development of tailored antifouling strategies for IWVs to reduce environmental impact and operational costs. Full article

To accurately manage precise feeding and water quality regulation in the rice–duck–crayfish integrated system (RDCI), the continuous monitoring of plankton and physicochemical parameters in the water was conducted from March 2022 to January 2023 in both the RDCI and the rice–crayfish continuous culture system (RCCC). The results showed that a total of 188 phytoplankton species and 92 zooplankton species were identified in the RDCI, whereas 152 phytoplankton species and 95 zooplankton species were detected in the RCCC. The phytoplankton community composition was similar between these two systems. For zooplankton, Rotifera was the dominant group. However, Chlorophyta and Bacillariophyta were the dominant phytoplankton groups. Compared with the RCCC, the RDCI exhibited lower plankton density during the crayfish-farming stage and overwintering stage, but higher plankton biomass during the crayfish-farming stage, overwintering stage, and rice maturity stage. The diversity indices, richness indices, and evenness indices of both phytoplankton and zooplankton in the RDCI were significantly higher than those in the RCCC. Correlation analysis indicated that water temperature, dissolved oxygen, total nitrogen, and ammonia nitrogen were the key environmental factors affecting plankton community structure. In summary, compared with the RCCC, the RDCI exhibits higher plankton diversity and better evenness, suggesting a more complex and stable community structure. The species composition of plankton and related indices indicate that the RDCI mitigates the degree of eutrophication in water during both the crayfish farming and the overwintering stages, while increasing nutrients levels during the rice planting stage. This approach is beneficial for reducing non-point-source pollution in agriculture and promoting green agricultural development. Full article

Photosynthetic algae–microbial fuel cells (PAMFCs) are attractive for energy-positive wastewater treatment and carbon mitigation. However, PAMFC performance under continuous flow is often constrained by limited cathodic electron-acceptor supply and unstable photosynthetic biofilms, while the extent to which cathode interfacial engineering can stabilize diurnal power output and assimilative NH₄⁺–N removal remains unclear. In this study, the sponge-like and petal-like ZnO_0.2-NiO@rGO-modified carbon fibers (ZnO_0.2-NiO@rGO-pCFs and ZnO_0.2-NiO@rGO-pCFp) and pre-fabricated carbon felt (pCF) were used as cathode materials to construct three sets of PAMFC systems. Under light–dark cycling, the engineered cathodes reached steady operation within about 6.5 d and increased the steady-state voltage to approximately 0.35 V, compared with approximately 0.08 V for pCF. Under continuous-flow conditions, cathodic NH₄⁺–N removal exhibited a stable diurnal rhythm, with higher removal during illumination at about 43–51% than in the dark at about 29–30%, consistent with algal assimilation as the primary nitrogen sink, while cathode modification mainly improved the cathodic microenvironment and response stability. Compared with pCF, the ZnO_0.2–NiO@rGO cathode enriched a more even, Chlorophyta-dominated algal biofilm with an approximate relative abundance of 80%, indicating that its selective interfacial environment favors biofilm stabilization and sustains in situ oxygen production and cathodic electron-acceptor supply. Consequently, the composite cathode enhanced voltage output and stabilized light-enhanced, assimilative NH₄⁺–N removal under aeration-free operation, while establishing an interpretable link between electrochemical performance and 18S rDNA-derived community assembly features, thereby providing a low-cost cathode design basis for nitrogen removal in wastewater treatment. Full article

The composition, ecological network characteristics, and community assembly mechanisms of eukaryotic communities in the sediments of typical water diversion rivers (WDRs) of the Eastern Route of the South-to-North Water Diversion Project were analyzed using 18S rRNA gene sequencing during the flood and non-flood seasons. Against the backdrop of global climate change and intensified anthropogenic disturbances, shifts in hydrological regimes induced by inter-basin water transfer projects have become key factors altering the structure and function of aquatic microbial ecosystems. Clarifying the spatiotemporal dynamics and assembly mechanisms of sedimentary eukaryotic communities in water diversion rivers under different hydrological conditions is crucial for understanding the ecological response of river ecosystems to water diversion and safeguarding the ecological security of diverted water resources. The eukaryotic communities were primarily composed of Bacillariophyta, Ciliophora, Arthropoda, and Chlorophyta. The composition and distribution patterns of eukaryotic communities exhibited distinct temporal and spatial shifts under varying hydrological regimes. Stochastic dispersal was identified as the primary driver of community assembly. During the flood season, eukaryotic communities showed increased complexity, more competitive interactions, and enhanced modularity, with species turnover being the dominant structuring process. During the non-flood season, eukaryotic communities exhibited higher spatial heterogeneity. Full article

The Mediterranean Sea is a biodiversity and climate change hotspot. The increase in seawater temperature affects marine ecosystems causing marine species to change their distribution and abundance. Such changes lead to alterations in community composition, often characterized by an increase in warm-affinity species over time, known as tropicalization of temperate seas. Monitoring programmes are useful for understanding the consequences of the ongoing transformations driven by ocean warming. In this study, underwater visual censuses (UVC) were conducted for fish and benthic communities at 24 stations of the Balearic Archipelago in 2022 and 2025. The comparison between both periods revealed an increase in the frequency of warm-affinity species, including the fishes Sparisoma cretense (Teleostea, Scaridae) and Caranx crysos (Teleostea, Carangidae); the invertebrates Telmatactis cricoides (Cnidaria, Actiniaria) and Hermodice carunculata (Annelida, Polychaeta, Amphinomidae) and the algae Penicillus capitatus (Chlorophyta, Ulvophyceae). Our findings highlight the importance of monitoring programmes to identify evidence of processes such as tropicalization and to provide timely information to respond to shifting marine ecosystems. Full article

Marine fish communities in the Yangtze River Estuary and Adjacent East China Sea (YRE-ECS) are subject to complex environmental gradients; however, their multidimensional assembly mechanisms remain insufficiently resolved. Here, we integrated environmental DNA (eDNA) metabarcoding, co-occurrence network analysis, and environmental profiling to examine fish community structure across vertical layers, hydrographic zones, and seasons. Vertically, surface communities dominated by pelagic-associated Perciformes and Clupeiformes showed more variable assembly patterns, whereas bottom communities enriched in Gobiiformes and Pleuronectiformes were more strongly associated with temperature and dissolved oxygen. Horizontally, among three zones delineated by salinity and hydrographic characteristics, the Mixed Transitional Water (MTW) supported the most diverse and interactive assemblages and functioned as an ecological connector between estuarine (EHSW) and offshore (OWSW) waters. Seasonally, community structure shifted markedly: spring communities exhibited higher diversity and denser trophic networks supported by zooplankton-rich, phototrophic plankton (e.g., Arthropoda, Bacillariophyta), whereas autumn communities were simpler, dominated by Chlorophyta and microbial taxa, with fish assemblages showing increased modularity and reliance on fewer planktonic groups. This seasonal pattern suggests a transition from diversified energy pathways to more constrained trophic coupling. βNTI and Mantel analyses jointly revealed a stratified environment-response-feedback framework driving community differentiation through combined stochastic and deterministic mechanisms. These findings highlight the importance of integrated spatial-temporal monitoring and suggest that protecting transitional zones and spring food-web integrity is critical for ecosystem resilience in the YRE-ECS. 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

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. Full article

The rapid rise in atmospheric CO₂ necessitates strategies for mitigation and valorization. Microalgae offer potential through simultaneous CO₂ capture and production of high-value biomolecules. Five Chlorophyta strains (A–E: Micractinium sp., Chlamydomonas sp., Micractinium sp., Chlorococcum sp., and Chlorella vulgaris) were isolated from temperate waters and soils and tested for growth and biochemical responses under controlled nitrogen availability (low: 0.346 g L⁻¹ nitrate; high: 0.6 g L⁻¹ nitrate + ammonia), carbon supply (low: 0.04% CO₂; high: 4% CO₂), and cultivation systems (batch reactors, fermenters, and varied illumination). Over 14 days, maximum dry biomass was achieved in batch cultivation with CO₂ sparging, low nitrogen, and continuous light, ranging from 1.47 g L⁻¹ (strain A) to 2.67 g L⁻¹ (strain D). Biomass composition varied: proteins, 25–45%; carbohydrates, 20–35%; and lipids, 18–28%. Nitrogen limitation promoted lipid accumulation (e.g., strain D: +40%) with concurrent protein decline (−25%). Chlorophyll a/b displayed strain-specific plasticity; high CO₂ generally increased chlorophyll, while nitrogen stress reduced it up to 50%. Overall, this study demonstrates that locally adapted Chlorophyta strains can achieve high biomass productivity under CO₂ enrichment while allowing for flexible redirection of carbon flux toward lipids, carbohydrates, or pigments through nutrient management. Among the tested isolates, strains D and E emerged as the most promising candidates for integrated CO₂ sequestration and biomass production, while strains B, C, and D showed strong potential for biodiesel feedstock; strain A for carbohydrate valorization; and strain E for chlorophyll extraction. Future research should focus on scale-up validation in pilot photobioreactors under continuous operation, optimization of two-stage cultivation strategies for lipid production, integration with industrial CO₂ point sources, and strain improvement using modern genomics-assisted breeding and genome-editing technologies. These efforts will support the translation of regional microalgal resources into scalable carbon-capture and bioproduct platforms. Full article

With the industry development of sea cucumber Apostichopus japonicus aquaculture, the indoor high cost and low survival rate have become serious problems. Therefore, it is necessary to optimize substrate selection for seedling protection in outdoor pond net cages. This study explores the succession of periphyton on the different substrate surface types, including a curvimurate net (CU), nylon mesh (NM), and ground cages (including a ground cage net (CN) and ground cage plate (CP)), and their effects on the seedling protection of sea cucumbers. In addition, we monitored the substrates’ dry weight, chlorophyll-a, and the community composition of substrates, alongside seedling growth, yield, and survival rate. The results show that a total of 7 phyla, 23 genera, and 31 species were detected on the substrates, with diatoms dominating (19 species) and Chlorophyta (4 species) being the main species. The CU had the highest total number of alga species attached, significantly higher than the other substrates in week 13 (p < 0.05). In week 9, the diatom density dropped to its lowest point, and, after September, it rose with the decrease in water temperature. In terms of dry weight with and without ash, CP increased rapidly in the early stage, with NM, CU, and CP being significantly higher than CN in week 13 (p < 0.05). The chlorophyll-a content showed a decreasing–increasing–decreasing trend, with CU reaching 3.62 ± 0.48 μg/cm² in the 13th week, significantly higher than other substrates (p < 0.05). Finally, the A. japonicus survival rate and yield in the CU group at week 12 were significantly higher than those in the NM and ground cage groups (p < 0.05). At week 17, the average weight, yield, and survival rate in the CU group were still optimal, with the yield 5.76 times that in the initial dosage. These results suggest that the CU has a suitable mesh size, has good permeability, and may stably support sediment, which is conducive to the growth of benthic diatoms. In addition, it can provide sufficient natural feed and a good habitat environment and is the preferred substrate for A. japonicus seedling protection in outdoor pond net cages. Full article