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This study is on fly ash (FA) concrete admixed with TiO2 nanoparticles (FAT), CaCO3 nanoparticles (FAC), and an equal ratio of TiO2 and CaCO3 nanoparticles (FATC) were exposed to seawater for 365 days in order to find the attachment of macrofoulants on their surface. The pH reduction studies were carried out in order to determine concrete deterioration in seawater, the results showed that FA specimens had more pH reduction than FAT, FAC and FATC. Total viable count, epifluorescence microscopy and denaturing gradient gel electrophoresis (DGGE) analysis confirmed the intensity of bacterial attachment and its diversity on FA, FAT, FAC, and FATC specimens. A systematic and comparative analysis predicted the overall relationship in terms of the dominant bacterial species on the different fly ash concrete specimens. To determine the biodeterioration of the fly ash concrete specimens in seawater, we used thermography experiments to evaluate the regions affected by bacteria on mortar specimens and confirmed that FA and FAC had more degradation and that FAT and FATC were the least degraded. Laser Raman Spectroscopy was interesting to find the white micron-sized particles of sulphur on FAC, FAT, and FATC specimens after 365 days immersed in seawater. We used a confocal laser scanning microscope to estimate the thickness of biofilm growth on FAT (13.91 0.38 mm), FATC (21.64 0.22 mm), FAC (33.56 0.26 mm), and FA (43.36 0.10 mm) specimens. The results showed that FAT and FATC specimens were the superior specimens, with enhanced biofouling and biodeterioration resistance in a seawater environment. Practical Applications: Fly ash is a waste material from thermal power plants and is used as a supplementary cementitious material in the construction industry. However, fly ash concrete has a slow hydration process and early strength problems. To overcome these problems, we used TiO2 and CaCO3 nanoparticles to enhance the properties of fly ash concrete. Nanoparticles have a high surface area and unique functional properties such as maintaining concrete pH, reducing porosity, enhancing pozzolanic activity, and so forth. In this study, we used TiO2 and CaCO3 nanoparticles to improve the strength of fly ash concrete and provide it with antibacterial properties. This study is significant in advancing our knowledge of fly ash concrete modified with nanoparticles and exposed to seawater with respect to its mechanical properties, durability, and antibacterial properties. Addition of nanoparticles upgraded the fly ash concrete towards its practical applications. [ABSTRACT FROM AUTHOR]

Gill disease is a major threat to aquaculture of Atlantic salmon, with an unknown and likely underestimated contribution from cnidarians such as jellyfish and biofouling hydroids. To better understand the risk and thus enable mitigation, technology for the certain identification of cnidarian-related gill damage is needed. We used the hydroid Ectopleura larynx in a case study to determine whether the exposure of salmon to nematocyst-bearing hydrozoans can be deducted via non-destructive PCR-based methods. In a field experiment, we evaluated (i) whether swabbing the inside of the gill operculum in farmed Salmo salar and subsequent PCR analysis can provide quantifiable information about the presence of E. larynx material in the gill chamber and, if so, (ii) whether the screening results correlate with histological assessments of gill damage. The developed PCR methods were able to detect the presence of biofouling hydroids in ambient water. However, despite exposure to suspended hydroid particle concentrations that did result in gill damage in some salmon, quantitative PCR results did not correlate with histological gill assessments. For opercular swabs to serve as a diagnostic tool for detecting biofouling-mediated gill damage in live salmon, increased specificity of genetic markers and improved sampling methods are needed. Animal trial permit no. 24252 (granted 06.07.2020, Norwegian Food Safety Authority). [ABSTRACT FROM AUTHOR]

The hormone Neuropeptide Y (NPY) plays critical roles in feeding, satiety, obesity, and weight control. However, its complex peptide structure has hindered the development of fast and biocompatible detection methods. Previous studies utilizing electrochemical techniques with carbon fiber microelectrodes (CFMEs) have targeted the oxidation of amino acid residues like tyrosine to measure peptides. Here, we employ the modified sawhorse waveform (MSW) to enable voltammetric identification of NPY through tyrosine oxidation. Use of MSW improves NPY detection sensitivity and selectivity by reducing interference from catecholamines like dopamine, serotonin, and others compared to the traditional triangle waveform. The technique utilizes a holding potential of −0.2 V and a switching potential of 1.2 V that effectively etches and renews the CFME surface to simultaneously detect NPY and other monoamines with a sensitivity of 5.8 ± 0.94 nA/µM (n = 5). Furthermore, we observed adsorption-controlled, subsecond NPY measurements with CFMEs and MSW. The effective identification of exogenously applied NPY in biological fluids demonstrates the feasibility of this methodology for in vivo and ex vivo studies. These results highlight the potential of MSW voltammetry to enable fast, biocompatible NPY quantification to further elucidate its physiological roles. [ABSTRACT FROM AUTHOR]

Commercial shipping activity plays a crucial role in the unintentional primary and secondary introduction of aquatic Non-Indigenous species (NIS), with ballast water (BW) and hull biofouling being the two major vectors of NIS transportation. The aim of this study is to identify potential high-risk donor port areas that may act as pools for NIS introduction in Saronikos Gulf, Greece. For the purpose of the study, we conducted a regional risk assessment and produced a NIS watch list based on the commercial vessel arrivals at the major ports of the Saronikos Gulf (Piraeus and Elefsis) for the period 2020–2022. In our risk analysis, we used the two most important factors for ship-mediated species introductions identified in the literature: salinity and biogeographic region of the voyage last origin ports. Then, combined with data on vessel arrivals, based on marine traffic data collected from the Marine Traffic online platform, we produced a NIS watch list for the study area. The most highrisk ports for primary introductions were found to be in the Temperate Northern Atlantic (e.g. Gemlik, Ambarli, Asyaport and Derince in Türkiye, Sines in Portugal), Western Indo-Pacific (e.g. Jeddah in Saudi Arabia, Aqaba in Jordan) and the Central Indo-Pacific (e.g. Singapore). For secondary introduction, the most high-risk voyage origin ports are located in the Levantine Sea (e.g. Limassol in Cyprus, Alexandria and Port Said in Egypt, Haifa and Ashdod in Israel, Iskenderun, Mersin and Nemrut in Türkiye), the Aegean Sea (e.g. Izmir in Türkiye) and the Ionian Sea (e.g. Marsaxlokk in Malta). Our watch list included 44 high risk and 13 medium risk NIS to be transferred to Saronikos Gulf. Of these, 38 high-risk species are already present in the Mediterranean, 6 high-risk species are absent from the Mediterranean and 18 species pose a high risk for both primary and secondary introduction. [ABSTRACT FROM AUTHOR]

Low‐input proteomics, also referred to as micro‐ or nanoproteomics, has become increasingly popular as it allows one to elucidate molecular processes in rare biological materials. A major prerequisite for the analytics of minute protein amounts, e.g., derived from low cell numbers, down to single cells, is the availability of efficient sample preparation methods. Digital microfluidics (DMF), a technology allowing the handling and manipulation of low liquid volumes, has recently been shown to be a powerful and versatile tool to address the challenges in low‐input proteomics. Here, an overview is provided on recent advances in proteomics sample preparation using DMF. In particular, the capability of DMF to isolate proteomes from cells and small model organisms, and to perform all necessary chemical sample preparation steps, such as protein denaturation and proteolytic digestion on‐chip, are highlighted. Additionally, major prerequisites to making these steps compatible with follow‐up analytical methods such as liquid chromatography‐mass spectrometry will be discussed. [ABSTRACT FROM AUTHOR]

Freshwater invaders threaten both natural ecosystems and human activities. An invasive freshwater sponge Heterorotula multidentata (Weltner, 1895) has been found for the first time in continental waters of Europe (Spain). It is a species native to Australia and New Zealand, from which it spread to Japan, being considered invasive. The species has been found in water intake grids of irrigation and drinking water systems in the basins of the Guadalquivir and Tajo rivers, affecting their hydrological functions. It has also been found growing on the invasive mussel Dreissena polymorpha in the Guadalquivir River. To assess the risks associated with invasive alien organisms, a detailed knowledge of their taxonomic status and distribution is necessary. A morphological and molecular evaluation confirmed that the specimens found in Spain belong to the Japanese type. A full morphological description and the fouling problems caused by the species are also provided. It is not yet clear how H. multidentata arrived at Spain, but indirect transport by other invasive freshwater species cannot be ruled out either, as H. multidentata has been found fouling the invasive species zebra mussel. [ABSTRACT FROM AUTHOR]

Balanomorph (acorn) barnacles are found throughout the world's coastal oceans, and their success is dependent on a hard, mineralized, outer shell. Although macro-scale morphology of barnacle shells has been studied extensively, relatively little is known about shell properties at the micron-scale and if such properties vary among species. We assessed shell structure, mechanics, and composition in seven species of balanomorph barnacles from five genera. Three species, Amphibalanus amphitrite, Amphibalanus improvisus, and Austrominius modestus, were laboratory-reared, enabling direct comparison of shell properties of barnacles grown under the same conditions for the same duration. Four other species, Semibalanus balanoides, Amphibalanus eburneus, Chthamalus stellatus, and Tetraclita rubescens, were field-collected. At the macro- and meso-scales, shell properties varied markedly among species, with differences in the number of shell plates, the presence of canals within the plates, mineralization of the base, and shell plate thickness. At the micron-scale, however, structure was remarkably similar among species. Plates of all species were constructed of irregular micron-scale crystallites, with a broad range of crystallite dimensions observed within the same shell. Similarly, micromechanical properties did not vary among species, regardless of testing orientation. Calcium carbonate was identified as calcite in all species assessed with no other mineral phases present, and calcium content did not vary among species. Hence, despite variation in the overall macro- and meso-scale morphology of barnacles, all appear to be built using the same, evolutionarily conserved, mineralization pathway. [ABSTRACT FROM AUTHOR]

Marine biofouling poses a major challenge to ship navigation and hinders the development of the shipping industry. Urgent action is required to tackle this problem through the implementation of innovative strategies. Antimicrobial peptides have garnered considerable attention due to their outstanding effectiveness, wide range of activity, and eco‐friendly characteristics. This study involved grafting the antibacterial peptide andricin 01 (AIGHCLGATL) onto the surface of an aluminum alloy, thereby creating a modified surface with antibacterial properties. In summary, amino groups were introduced onto the surface of aluminum alloys through the silanization process using (3‐aminopropyl) triethoxysilane (APTES), and then the peptides were covalently immobilized on the treated surface using glutaraldehyde as a cross‐linking agent. The successful modification of the peptide was confirmed by Fourier transform‐infrared spectroscopy (FT‐IR) and X‐ray photoelectron spectroscopy (XPS) analysis. The antimicrobial peptide‐modified aluminum alloy surfaces exhibited significant bactericidal activity, killing 75.3% of Bacillus sp. and 85.5% of Escherichia coli, while achieving antifouling efficiencies of 88.6% and 90.7% against Bacillus sp. and E. coli, respectively. Furthermore, molecular dynamics simulations showed that the inserted of the peptides into the phospholipid membrane caused a change in the local membrane curvature, which eventually led to membrane rupture. These results provide valuable information for the application of antimicrobial peptides in the field of antifouling and the elucidation of antifouling mechanisms. [ABSTRACT FROM AUTHOR]

Unionid mussels are globally threatened by several human disturbances, including the introduction of non-native species. Among these, biofouling zebra and quagga mussels of Ponto-Caspian origin are considered to be especially detrimental to unionid locomotion, filtration and physical condition. The aim of our study was to determine and compare the impact of dreissenid fouling and/or presence on locomotion and burrowing of the native Unio tumidus and invasive Sinanodonta woodiana, a novel invader expanding its range in Europe in recent decades. We tested unionids collected from Lake Balaton (central Europe) that were fouled by dreissenids (zebra and quagga mussels mixed), cleaned of fouling or non-fouled (collected without any signs of dreissenid fouling). Moreover, unionids were tested in the presence or absence of other fouled individuals and dreissenids isolated in mesh bags to determine the influence of direct fouling and presence of dreissenids in the environment on unionid behaviour. Movement initiation time, locomotion distance and burrowing level were retrieved from videos recorded for 24 hours. Direct fouling affected only the behaviour of U. tumidus, limiting their burrowing and delaying movements. After removal of fouling, movement timing returned back to normal, but mussels still burrowed less than the control non-fouled individuals, indicating persisting effects of fouling on physical condition. Moreover, U. tumidus reduced their locomotion in the presence of fouled unionids. Sinanodonta woodiana responded to the presence of dreissenids (especially quagga mussels) with increased burrowing. These different responses of the two unionid species to Dreissena spp. indicate that biofoulers may influence biotic interactions between the unionids by promoting the invasive species (less susceptible to negative effects of fouling). Moreover, S. woodiana may indirectly affect U. tumidus through apparent competition, constituting an environmental reservoir of biofoulers exerting a stronger impact on the native species. [ABSTRACT FROM AUTHOR]

The damage caused by corrosion in metallic materials is a problem that produces substantial economic and environmental costs. According to the World Bank, the global annual GDP (Gross Domestic Product) in corrosion costs was approximately 96.1 trillion US dollars for 2021, about 20% are due to the corrosion produced by the presence of bacteria, however there are no statistics related to environmental damages produced by this problem [1]. Microbial corrosion activity on metallic surfaces, cannot be classified as a corrosion type, but a process or mechanisms that can influence, accelerate and even initiate it, regardless the type of corrosion generated. The only necessary condition to initiate or accelerate the microbial corrosion on a metallic surface is the growth of biofilms. Biofilms are very complex systems, due to the large amount and types of microorganisms that can grow in it, the metabolic activities that can be developed, and the chemical products, which can attack the metallic materials, causing great deterioration. Due to the complex nature of these processes, specifics norms, procedures and methodologies of operation, patented or established to study, evaluate or fight the action of biofilms are scarce [2,3]. However, some industrial methods have being reported to mitigate their effects [4-7]. In this work it is presented an information review compiled by bibliographic search related to some relevant aspects about biofilms and microbial corrosion, electrochemistry, microscopic studies and preventive actions. [ABSTRACT FROM AUTHOR]

Recreational vessels are an important pathway for spreading marine non‐indigenous species (NIS) around coastal environments globally. However, most vessels are not tracked, limiting our ability to map their movements and identify locations at greater risk of NIS introductions.Using New Zealand as a case study, we quantified spread and risk patterns of recreational vessel movements, using a web‐based survey allowing the more than 1,800 respondents to map significant trips with over 12,000 visits. These vessel routes were used to build a network model representing nationwide recreational vessel movements. Two proxies were used to quantify the risk of introduction of marine NIS: (i) incoming hull length and (ii) cumulative residency periods at sites.There was significant variation in the distances travelled, the destinations they visited and the duration of their stays. New Zealand's recreational boating network contained 317 destinations with over 4,000 unique connections, concentrated within two distinct areas of the country. Network‐based metrics and risk proxies quantified the relative importance of domestic locations as incursion or spreading hubs for NIS. This approach highlighted several areas that pose high relative biosecurity risk within the national network, but are underrepresented within current surveillance programmes.Synthesis and applications. Our study demonstrates how the movement dynamics of recreational vessels can be quantified at a regional scale to inform proactive management. The identification of spreading hubs and locations at particular risk of NIS introductions, enables managers to design risk‐based and effective surveillance and monitoring programmes. Our network‐based approach to determine the biosecurity implications posed by recreational vessels is transferable to other parts of the world. It enables managers to understand the distribution of risk within an area of interest (e.g. a jurisdiction) and develop optimised approaches for mitigating impact. [ABSTRACT FROM AUTHOR]

Understanding the magnitude of biosecurity risks in aquatic environments is increasingly complex and urgent because increasing volumes of international shipping, rising demand for aquaculture products, and growth in the global aquarium trade, are accelerating invasive alien species spread worldwide. These threats are especially pressing amid climate and biodiversity crises. However, global and national biosecurity systems are poorly prepared to respond because of fragmented research and policy environments, that often fail to account for risks across sectors or across stakeholder needs and fail to recognize similarities in the processes underpinning biological invasions. In the present article, we illustrate the complex network of links between biosecurity threats across human, animal, plant, and environment sectors and propose a universal approach to risk assessment. One Biosecurity is a holistic, interdisciplinary approach that minimizes biosecurity risks across human, animal, plant, algal, and ecosystem health and is critical to reduce redundancy and increase cross-sectoral cohesion to improve policy, management, and research in aquatic biosecurity. [ABSTRACT FROM AUTHOR]

Fouling and biofouling remain significant challenges in seawater desalination plants. One practical approach to address these issues is to develop anti-biofouling membranes. Therefore, novel hybrid zinc phthalocyanine/polyvinylidene fluoride-co-hexafluoropropylene (Zn(4-PPOx)4Pc/PVDF-HFP) membranes were prepared by electrospinning to evaluate their properties against biofouling. The hybrid nanofiber membrane was characterized by atomic force microscopy (AFM), attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, and contact angle measurements. The theoretical calculations of PVDF-HFP, Zn(4-PPOx)4Pc), and Zn(4-PPOx)4Pc/PVDF-HFP nanofibers were performed using a hybrid functional RB3LYP and the 6-31 G (d,p) basis set, employing Gaussian 09. DFT calculations illustrated that the calculated physical and electronic parameters ensured the feasibility of the interaction of PVDF-HFP with Zn(4-PPOx)4Pc via a halogen–hydrogen bond, resulting in a highly stable and remarkably reactive structure. Moreover, molecular electrostatic potential (MEP) maps were drawn to identify the reactive regions of the Zn(4-PPOx)4Pc and PVDF-HFP/Zn(4-PPOx)4Pc nanofibers. Molecular docking analysis revealed that Zn(4-PPOx)4Pc has highest binding affinity (−8.56 kcal/mol) with protein from S. aureus (1N67) mainly with ten amino acids (ASP405, LYS374, GLU446, ASN406, ALA441, TYR372, LYS371, TYR448, LYS374, and ALA442). These findings highlight the promising potential of Zn(4-PPOx) 4Pc/PVDF-HFP nanocomposite membranes in improving the efficiency of water desalination by reducing biofouling and providing antibacterial properties. [ABSTRACT FROM AUTHOR]

Simple Summary: Marine biofouling is the undesirable accumulation of marine organisms onto man-made surfaces, which causes severe economical and environmental consequences. In recent years, using natural products as environmentally friendly antifouling agents to combat foulers has been a promising approach. However, the search for effective antifouling agents is hampered by the lack of well-defined conserved molecular targets responsible for regulating the larval settlement in fouling organisms. In this study, an in silico approach was used to screen the natural compounds' libraries against silk gland factor 1 (SGF1), which is responsible for the larval settlement of the fouling mussel Mytilopsis sallei. It was found that the targeted binding compounds against SGF1 could significantly affect the larval settlement, foot proteins' gene expression, and byssus secretion of adults in M. sallei. The laboratory bioassay results are promising, even though field trials are necessary to confirm the in silico results. Hence, this study paves the way for new experimental studies to be carried out for finding environmentally friendly antifouling agents by using SGF1-targeted compounds. Most fouling organisms have planktonic larval and benthic adult stages. Larval settlement, the planktonic–benthic transition, is the critical point when biofouling begins. However, our understanding of the molecular mechanisms of larval settlement is limited. In our previous studies, we identified that the AMP-activated protein kinase-silk gland factor 1 (AMPK-SGF1) pathway was involved in triggering the larval settlement in the fouling mussel M. sallei. In this study, to further confirm the pivotal role of SGF1, multiple targeted binding compounds of SGF1 were obtained using high-throughput virtual screening. It was found that the targeted binding compounds, such as NAD+ and atorvastatin, could significantly induce and inhibit the larval settlement, respectively. Furthermore, the qRT-PCR showed that the expression of the foot proteins' genes was significantly increased after the exposure to 10 μM NAD+, while the gene expression was significantly suppressed after the exposure to 10 μM atorvastatin. Additionally, the production of the byssus threads of the adults was significantly increased after the exposure to 10–20 μM of NAD+, while the production of the byssus threads was significantly decreased after the exposure to 10–50 μM of atorvastatin. This work will deepen our understanding of SGF1 in triggering the larval settlement in mussels and will provide insights into the potential targets for developing novel antifouling agents. [ABSTRACT FROM AUTHOR]

This work investigated the trade-off among cavitation erosion resistance, corrosion resistance, and antifouling properties in HVOF-sprayed WC-10Co4Cr coatings. By adding 316L stainless steel (316L) and copper to WC-10Co4Cr coatings, this work aimed to enhance their antifouling ability while maintaining their cavitation erosion and corrosion resistances, presenting a comprehensive evaluation of the modified coatings, including their microstructure, hardness, fracture toughness, and resistance to cavitation erosion, corrosion, and biofouling. The results revealed that Cu addition significantly improved the antifouling property but at a cost of the compromised cavitation erosion and corrosion resistances. In contrast, 316L enhanced the cavitation erosion and corrosion resistances but did not effectively improve the antifouling property. The dual addition of Cu and 316L demonstrated a balanced performance in all three aspects. This research contributed to the development of HVOF-sprayed WC-CoCr coatings suitable for marine environments, suggesting further optimization possibilities by altering Cu and 316L contents. [ABSTRACT FROM AUTHOR]

A biofilm is a layer of microbes that have aggregated to form a colony. The colony attaches to a surface with a slime layer which protects the microorganisms, promoting their growth and survival. Biofilms occur in various environments such as soils, sediments, wastewater, water pipelines, water purifying systems, cooling water systems, medical devices, archaeological monuments, marine vessels, and hospitals. Biofilms may induce adverse effects such as fostering drug-resistant strains. Here, we review biofilms with focus on their formation, occurrence in water systems, impact, microbial interactions, and characterization methods. Communication includes cell-to-cell interactions by quorum sensing, interactions mediated by flagella, gene, and signaling molecules, and interactions mediated by extracellular polymeric substances. Characterization methods comprise surface-enhanced Raman scattering spectroscopy, confocal laser scanning microscopy, scanning electron microscopy, fluorescence microscopy, sensors, and metagenomics analysis. [ABSTRACT FROM AUTHOR]

Despite the development of numerous coating techniques and materials, today’s anti-biofouling applications require coatings that are facile and mechanically robust in nature. Studies on the hydrophobicity of rare-earth oxides have risen due to their unusual chemical properties; ytterbium oxide is one such oxide substance. In this study, spray combustion was used to create a hydrophobic coating of ytterbium oxide (Yb2O3) on a stainless steel (SS) substrate, which was then vacuum-treated. GI-XRD analysis confirmed the sesquioxide cubic crystalline structure of Yb2O3. FESEM images displayed an underneath wavy morphological coating with discrete particles on the surface. The thickness and roughness were ~12 and ~0.17 µm, respectively. When 5 and 10 N loads were applied, the coating showed better scratch hardness than uncoated SS. Water contact angle (WCA) <10° indicated superhydrophilicity in the fabricated coating. After vacuum treatment, it became hydrophobic, and the WCA was 128°; because of the increment in the relative area fraction of the C–H bond. The proportion of area covered by blue–green algae (Phormidium sp.) on vacuum-treated Yb2O3 coating was only 3% compared to uncoated SS samples, 80%. [ABSTRACT FROM AUTHOR]

Ecologically safe antifouling solutions have received growing attention since the acknowledgment of the environmental risks of traditional biocides used currently. Given that bacteria constitute the initial stage of the biofouling process, this work aims to evaluate the antifouling potential of aquatic macrophyte extracts in inhibiting biofilm-forming bacteria and to evaluate their ecotoxicological effects on target and nontarget organisms (Thalassiosira pseudonana and Nitokra sp.). For this, the ability of 25 macrophyte extracts to inhibit and eradicate single and multispecies estuarine biofilms was evaluated. The extracts and respective serial dilutions that showed a biofilm inhibitory effect ≥ 60% were evaluated in ecotoxicological assays. Of the 25 extracts, only 6 extracts inhibited the biofilm ≥ 60%. The extracts of Cabomba caroliniana and Schoenoplectus californicus stood out as having a biofilm inhibitory effect ≥ 80% (p < 0.05) for bacterial isolates and ≥ 70% (p < 0.05) for multispecies biofilms. Furthermore, these extracts showed no toxic effects on nontarget organisms. These results demonstrate the biotechnological potential of macrophyte compounds. [ABSTRACT FROM AUTHOR]

Ascidian biofouling generates significant challenges to bivalve aquaculture. Their rapid spread across almost every available surface leads to increased maintenance costs and reduced yields in shellfish farming. In addition, ascidians may introduce pathogens or toxins, further compromising the health and marketability of bivalve stocks and thereby necessitating strict management strategies to manage these impacts. The aim of this study was the evaluation of different management practices for eliminating ascidian fouling and the identification of the best method for Mytilus galloprovincialis (Lamarck, 1819) aquaculture farms. The effects of different anti-fouling treatments as well as their interactive outcomes were examined by conducting two experiments. Various experimental procedures were applied, including the temporally differential washing of mussels, air exposure and immersion in 50 ppt and 70 ppt salinity solutions, as well as the combination of these applications. All treatments reduced the number of ascidian colonies on mussel socks but at varying proportions. Immersing mussel socks in a 70 ppt salinity solution followed by air exposure for 1 day was the most efficient method and led to a 93% eradication. [ABSTRACT FROM AUTHOR]

During the cultivation of Ulva fenestrata in a land-based aquaculture system, the colonisation of the water tanks' surfaces and eventually the macroalgal biomass by the biofouling diatom Fragilariopsis oceanica compromises the production process. Since germanium dioxide (GeO2) is an effective growth inhibitor of diatoms, this study aimed to understand how it affects the presence of F. oceanica and the photosynthesis and growth of U. fenestrata as a primary parameter contribution to the biomass production. A toxicological dose-response experiment showed that the diatom's growth was inhibited at the low GeO2 concentration of 0.014 mg l−1. In contrast, the photosynthetic performances and growth rates of U. fenestrata remained unaffected under a wide GeO2 concentration range (0.022–2.235 mg l−1) in small- and large-scale experiments in 1-l glass beakers and 100-l Plexiglass water tanks, respectively. In the latter, the diatom density in the tanks was reduced by 40 %. The costs arising from the use of GeO2 can range between €2.35 and €8.35 kg−1 fresh weight of produced U. fenestrata biomass under growth conditions resulting in growth rates of 20 and 11.5 % d−1, respectively. GeO2 is an effective agent to control biofouling diatoms such as F. oceanica during the land-based biomass production of U. fenestrata. [ABSTRACT FROM AUTHOR]

Seaweed farming is expanding in Europe and may provide environmental benefits similar to those from natural kelp forests and shellfish farms, including habitat provisioning. Few studies have substantiated these claims however, and it remains uncertain whether seaweed farms will support similar biodiversity to kelp forests or provide valuable long-term habitat beyond the harvest season. We repeatedly surveyed an integrated sugar kelp (Saccharina latissima) and blue mussel (Mytilus edulis) farm in southwest UK to compare epibiont assemblages between cultivated kelps, to those from three nearby wild kelp populations, and to epibionts on farmed mussel lines and unseeded 'bare' lines. We found farmed kelps supported over 217 times the abundance of epibionts living on wild kelps at harvest time, however, taxonomic diversity per kelp was lower at the farm. Farmed kelp assemblages were dominated by amphipods, which were present on the wild kelps but in much lower numbers. Farmed kelp also supported distinct assemblages to cultivated mussels, which were similarly dominated by amphipods, but hosted higher relative abundances of crabs, echinoderms, worms and red algal biomass. The bare lines were heavily colonised by another pseudo-kelp, Saccorhiza polyschides, which supported similar epibiont assemblages to the seeded S. latissima lines. Our findings indicate that cultivating bivalves alongside seaweed can increase habitat provisioning at a seaweed farm and extend its permanence beyond typical seaweed cultivation periods as bivalves have longer, continuous farming periods. However, the presence of mussels will likely influence the epibiont assemblages on the farmed kelp, which are distinct from wild kelp populations. [ABSTRACT FROM AUTHOR]

Global water scarcity is a threat that can be alleviated through membrane filtration technologies. However, the widespread adoption of membranes faces significant challenges, primarily due to membrane biofouling. This is the reason why membrane modifications have been under increasing investigation to address the fouling issues. Antibacterial membranes, designed to combat biofouling by eliminating microorganisms, offer a promising solution. Within this study, flat sheet ultrafiltration (UF) membranes with integrated photocatalytic zinc oxide (ZnO) nanoparticles were developed, characterized, and assessed through filtration and fouling tests. The antibacterial properties of the membranes were conducted in static tests using Gram-negative bacteria—Escherichia coli—and natural tap water biofilm. The results demonstrated a notable enhancement in membrane surface wettability and fouling resistance. Furthermore, the incorporation of ZnO resulted in substantial photocatalytic antibacterial activity, inactivating over 99.9% of cultivable E. coli. The antibacterial activity persisted even in the absence of light. At the same time, the persistence of natural tap water organisms in biofilms of modified membranes necessitates further in-depth research on complex biofilm interactions with such membranes. [ABSTRACT FROM AUTHOR]

Tanjung Emas Port is the entry and exit point for trade commodities, both regional and international filled with many ships. This condition makes biofouling a very massive process in that place by various types of marine bacteria. The initial formation of a biofilm is relevant to bacterial diversity, colonization and adhesion. The objective of the study was assessing bacterial diversity in relation to with biofouling within Tanjung Mas Port Semarang, by using 16S rRNA eDNA metabarcoding Next-Generation Sequencing (NGS). Seawater samples from aquatic sites of Tanjung Mas harbor was used for DNA extraction and amplification of the 16S rRNA V-3-V4 hypervariable region, followed by sequencing and library construction of eDNA Metabarcoding. Sequence processing and analysis was performed in QIIME 2 and RStudio using DADA2 for advanced sequencing processing and Phyloseq. The results of this research showed that bacteria is the predominant taxon constituting 100% of the community. The taxon consists of Proteobacteria (49.38%), Bacteroidota (8.67%), and Firmicutes (8.88%). Alphaproteobacteria (20.92%) and Gammaproteobacteria (12.39%) dominate at the Class level, emphasizing their versatility and ecological influence. At the Order and Family levels reveals the prevalence of Rhodobacterales (10.04%), Chitinophagales (2.53%), Rhizobiales (3.61%), Rhodobacteraceae (5.67%), Saprospiraceae (3.63%), and Rhizobiaceae (2.15%). It was found that the unculturable taxa dominance in Tanjung Mas Port was 44.66%. These taxonomic entities contribute significantly to the taxonomic and functional diversity of the microbial community, influencing nutrient cycling, organic matter degradation, ecosystem stability and biofilm formation. [ABSTRACT FROM AUTHOR]

Surface fouling poses a significant challenge that restricts the analytical performance of electrochemical sensors in both in vitro and in vivo applications. Biofouling resistance is paramount to guarantee the reliable operation of electrochemical sensors in complex biofluids (e.g., blood, serum, and urine). Seeking efficient strategies for surface fouling and establishing highly sensitive sensing platforms for applications in complex media have received increasing attention in the past. In this review, we provide a comprehensive overview of recent research efforts focused on antifouling electrochemical sensors. Initially, we present a detailed illustration of the concept about biofouling along with an exploration of four key antifouling mechanisms. Subsequently, we delve into the commonly employed antifouling strategies in the fabrication of electrochemical sensors. These encompass physical surface topography (micro/nanostructure coatings and filtration membranes) and chemical surface modifications (PEG and its derivatives, zwitterionic polymers, peptides, proteins, and various other antifouling materials). The progress in antifouling electrochemical sensors is proposed concerning the antifouling mechanisms as well as sensing capability assessments (e.g., sensitivity, stability, and practical application ability). Finally, we summarize the evolving trends in the field and highlight some key remaining limitations. [ABSTRACT FROM AUTHOR]

Inter-individual transmission of cancer cells represents a unique form of microparasites increasingly reported in marine bivalves. In this study, we sought to understand the ecology of the propagation of Mytilus trossulus Bivalve Transmissible Neoplasia 2 (MtrBTN2), a transmissible cancer affecting four Mytilus mussel species worldwide. We investigated the prevalence of MtrBTN2 in the mosaic hybrid zone of M. edulis and M. galloprovincialis along the French Atlantic coast, sampling contrasting natural and anthropogenic habitats. We observed a similar prevalence in both species, probably due to the spatial proximity of the two species in this region. Our results showed that ports had higher prevalence of MtrBTN2, with a possible hotspot observed at a shuttle landing dock. No cancer was found in natural beds except for two sites close to the hotspot, suggesting spillover. Ports may provide favourable conditions for the transmission of MtrBTN2, such as high mussel density, stressful conditions, sheltered and confined shores or buffered temperatures. Ships may also spread the disease through biofouling. Our results suggest ports may serve as epidemiological hubs, with maritime routes providing artificial gateways for MtrBTN2 propagation. This highlights the importance of preventing biofouling on docks and ship hulls to limit the spread of marine pathogens hosted by fouling species. [ABSTRACT FROM AUTHOR]

Whilst it is now well recognized that some natural surfaces such as seemingly fragile insect wings possess extraordinary antimicrobial properties, a quest to engineer similar nanopatterned surfaces (NPSs) is ongoing. The stake is high as biofouling impacts critical infrastructure leading to massive social and economic burden with an antimicrobial resistance (AMR) issue at the forefront. AMR is one of the most imminent health challenges the world is facing today. Here, in the effort to find more sustainable solutions, the NPSs are proposed as highly promising technology as their antimicrobial activity arises from the topographical features, which could be realized on multiple material surfaces. To fully exploit these potentials however, it is crucial to mechanistically understand the underlying killing pathways. Thus far, several mechanisms have been proposed, yet they all have one thing in common. The antimicrobial process is initiated with bacteria contacting nanopatterns, which then imposes mechanical stress onto bacterial cell wall. Hence, the activity is called "mechano-bactericidal". From this point on, however, the suggested mechanisms start to diverge partly due to our limited understanding of force interactions at the interface. The aim of this mini review is to analyze the state-of-the-art in proposed killing mechanisms by categorizing them based on the characteristics of their driving force. We also highlight the current gaps and possible future directions in investigating the mechanisms, particularly by shifting towards quantification of forces at play and more elaborated biochemical assays, which can aid validating the current hypotheses. [ABSTRACT FROM AUTHOR]

Antimicrobial hybrid polymer composites are developed for application in floating solar power plants. To avoid the degradation of the floater because of microbes living in the water as well as possible biofouling, zinc oxide (ZnO) is used as an antimicrobial agent, varying the weight percent (1, 2, and 3 wt%) within the high-density polyethylene (HDPE) matrix, along with carbon black (CB) as a reinforcing agent (1, 1.5, 2, and 2.5 wt%). Escherichia coli (facultative anaerobic) and Pseudomonas aeruginosa (aerobic-facultatively anaerobic) gram-negative bacteria formed a biofilm on HDPE in a 96-well plate for 5 days. In vitro, biofilm formation was determined by measuring absorbance (A420) in crystal violet dye, and the colony-forming unit (CFU) was determined by the spread plating technique. The biofilm formation and disruption are observed through a scanning electron microscope (SEM), where both the CFU and the SEM revealed uniform formation of biofilm onto neat HDPE. The best performance in terms of reduced biofilm formation and biofouling onto HDPE floaters was achieved for E. coli (ZnO: 2 wt% and CB: 2 wt%), whereas for Pseudomonas aeruginosa (ZnO: 3 wt% and CB: 2 wt%). Application of greener polymers and nanoparticles for future studies is highly recommended. [ABSTRACT FROM AUTHOR]

In the present research, a single-step electrospinning technique was implemented to develop homogeneous hydrophilic nanostructures with a self-cleaning characteristic based on non-woven polyurethane (PU) altered by quaternary ammonium salts (QAS). By transferring the nanofibrous structures to the polyethylene terephthalate substrate, the filtering membranes were fabricated. The fabricated PU and PU/QAS membranes were compared and characterized for assessing their self-cleaning properties. The synthesized nanofibers were mechanically tested and also characterized by scanning electron microscopy. At low trans-membrane pressure of 7.5 kPa, water permeation flux and biofouling effect of electrospun nanocomposite membrane performance were primarily studied by means of dead-end filtration. Following a 5-day filtration, the modified nanofibrous structure displayed promising results in the recovery of the flux after a day 3 and inhibited the development of biofilm as well. The tensile strength and modulus of PU-QAS were 7.5MP and 31.7% higher compared to PU membrane. The pore size was also observed to be 360n in PU, while for PU-QAS, it was observed as 340 nm. It was concluded that the developed PU/QAS membrane can be restored to its original flow properties by cleaning with tap water. [ABSTRACT FROM AUTHOR]

Marine worms of the family Serpulidae (Annelida) construct calcareous tubes that adhere to hard substrata. The tubes of the Spirobranchus kraussii complex have a flat projection, known as a 'flap', over the opening of the tube. In the present study, we examined the reconstruction growth rates of the flap of Spirobranchus akitsushima after artificial removal, compared with the normal growth rates (control), for approximately a month at a study site in Shirahama, Wakayama, Japan. Although the difference in the length of the flap on day 8 compared with the original length (before the removal treatment) was significant in the treatment group, the differences became nonsignificant after day 13. The flap growth rate was found to be higher than the growth rates of the tubes of other serpulid species, including Spirobranchus sp. 5 sensu Kobayashi & Goto (2021) of the S. kraussii complex, as reported in previous studies. In contrast, the length of the flap in the control group did not differ significantly during the survey period. These results indicate that the flap is more quickly reconstructed after removal compared with growth under normal conditions. Our findings imply that the flap may be of importance for the survival of S. akitsushima. [ABSTRACT FROM AUTHOR]

This study focuses on the shaft power at the neutral angle of a controllable pitch propeller to analyze the change in the required power due to propeller fouling. It is named and defined as a power for keeping propeller's rotation (RP) because a propeller does not generate the net thrust to push the hull but dissipates the power to keep its constant speed. Statistical analysis was conducted using a decade of the observed data from a research vessel. This study assumed that the change in RP can be considered as an indicator showing the state of propeller fouling. In addition, the state of fouling on the hull can be estimated indirectly based on RP because the data correlated the shaft power under several operating conditions with RP on the same voyage. The fouling state was classified into three conditions based on RP. The comparison of shaft power at the same ship speed between the clean condition and the serious fouled condition showed that the shaft power was increased by 35% on average due to fouling. When the ship navigates under 10 knots, propeller fouling has a larger impact on the increase in shaft power than hull fouling. [ABSTRACT FROM AUTHOR]

This research aimed to reduce reliance on chemical antifouling agents; it was conducted at depths of 0.5 and 1.5 meters in the Eastern Harbor, at Alexandria, Mediterranean Sea. This study delves into the realm of environmentally sustainable antifouling solutions by exploring the efficacy of natural crude extracts from two Red Sea sponge species, Acanthella acuta (Extract A) and Carteriospongia sp. (Extract B). The results revealed a rich diversity of fouling organisms, encompassing six phyla, seven classes, eleven orders, twenty-two families, and thirty-three species. Noteworthy absences were noted at specific depths, indicating depth-dependent variations in fouling communities . The application of extract A at 0.5 meters depth demonstrated significant reductions in fouling biomass and shifts in dominant species. Treatment 3 stood out with the lowest biomass (9.69 ± 2.83 g/m² ) and the fewest species (only 2 species). At 1.5 meters depth, extract B exhibited consistent trends with treatment 6 displaying the lowest biomass (20.85 ± 23.35 g/m2 ) and also species diversity (only 2 species). Meanwhile, Extract B showcased compelling antifouling potential. At 0.5 meters depth, treatment 4 exhibited notable reductions in fouling biomass, dominated by Balanus amphitrite, Balanus eburneus, and Balanus sp. At 1.5 meters depth, treatment 6 emerged as the most effective, with the lowest biomass (249.3 ± 120.4 g/m² ) and a streamlined species composition. This study underscores the promise of natural crude extracts from the Red Sea sponges as potent alternatives for environmentally friendly antifouling strategies. The observed variations in fouling biomass and species composition offer critical insights for the development and application of these extracts in combating fouling organisms, presenting a significant stride toward sustainable marine ecosystem conservation. [ABSTRACT FROM AUTHOR]

The use of biocidal agents is a common practice for protection against biofouling in biomass-rich environments. In this paper, oligohexamethyleneguanidine (OHMG) polymer, known for its biocidal properties, was further modified with para-aminosalicylic acid (PAS) to enhance its properties against microorganisms coated with a lipid membrane. The structure of the product was confirmed by 1H NMR, 13C NMR, and FTIR spectroscopy. The values of the minimum inhibitory concentration (MIC) against Mycobacterium smegmatis ATCC 607 and Pseudomonas chlororaphis 449 were found to be 1.40 and 1.05 μg/mL, respectively. The synthesized substance was used as an additive to the polymer matrix of the composite optical oxygen sensor material. A series of samples with different contents of OHMG-PAS was prepared using a co-dissolution method implying the fabrication of a coating from a solution containing both polymers. It turned out that the mutual influence of the components significantly affects the distribution of the indicator in the matrix, surface morphology, and contact angle. The optimal polymer content turned out to be wt.3%, at which point the water contact angle reaches almost 122°, and the fouling rate decreases by almost five times, which is confirmed by both the respiratory MTT assay and confocal microscopy with staining. This opens up prospects for creating stable and biofouling-resistant sensor elements for use in air tanks or seawater. [ABSTRACT FROM AUTHOR]

Background: During lifespan of reverse osmosis systems applied in seawater desalination plants, a common phenomenon of undesirable growth and accumulation of biological material known as biofouling occurs. Microbial cells are first settlers, attaching and enclosing themselves in extracellular polymeric substances -biomass accumulation usually referred to as microfouling or biofilms, which becomes a serious issue when having a detrimental effect on materials or hampering industrial processes. Thus, control of microfouling on reverse osmosis membranes is crucial since chemical and physical treatments are usually costly and ineffective. In this context, even though microorganisms are the source of the problem, they can also provide possible solutions due to their capacity to produce secondary metabolites, being several of these competition mediators secreted compounds (i.e., bioactive molecules) produced during the stationary phase (e.g., lipases, proteases, DNases and other enzymes with alginate lyase and xanthine oxidases). Such bioactive substances can be utilized against the development of biofilms. Considering biofouled surfaces a niche for complex microbial interactions, here we have used reverse osmosis membranes and cartridge filters applied in a seawater desalination plant as a source for the isolation of bacteria with anti-fouling potential, among other biotechnological applications. Results: We obtained 27 bacterial isolates able to secrete exoenzymes displaying a wide array of bioactivity such as lipases, alginases, and glucosidases, among others. Additionally, we showed two main candidates able to inhibit the growth of common microbial colonizers of ROM and cartridge filter. Conclusions: These results highlight the potential biotechnological application of bioactive molecules against biofouling formation. [ABSTRACT FROM AUTHOR]

Non-indigenous species have been widely recognized as major drivers of biodiversity loss. However, management in marine ecosystems entails particular challenges of detection and control, with an approach which requires stakeholders from the government, academia and the public. To generate a first approach to what should be the national Chilean agenda for non-indigenous species (NIS) management, a workshop was convened at the Universidad Católica del Norte in Coquimbo on the past, present and future of marine bioinvasions in Chile. The workshop, with more than 60 participants, including academics and public services, gathered information from the published literature on the state of the art of marine bioinvasions in Chile and proposed a work agenda for the coming years. The results highlight that the design and implementation of more focused and effective management policies and programs will be required to potentially reduce the rates of new invasions and identify mitigation strategies. We present the first proposed NIS research and management agenda for Chile developed through a collaborative process between researchers and the Chilean government, with a joint vision of both the challenges and solutions. [ABSTRACT FROM AUTHOR]

Research effort concerning biological invasions has increased significantly but the pressure of multiple vectors of introduction (MVI) on coastal areas is still poorly understood. The aim of this work is to provide a comprehensive list of non-indigenous species (NIS) occurring in the Sado estuary, identify and prioritize MVI to deliver recommendations for bioinvasions management. Fouling communities were sampled in five artificial systems during 2021 and 2022. Additionally, a thorough literature review was performed to provide a comprehensive NIS database for the Sado estuary. Native distribution of NIS was classified based on biogeographic realms and the most likely pathways and vectors of introduction were assigned to each introduction. A total of 52 NIS were catalogued, predominantly arthropods, 22% of which were reported until 2005, while 40% were recorded in the last 2 years. We also reported four new NIS to Portugal. Most NIS were native from the Temperate Northern Pacific and the Temperate Northern Atlantic. Shipping related vectors were dominant (61%). Aquaculture was not directly linked to many invasions (8%), however contaminants on animals was the second most significant vector (23%). Our results highlight the need for managing MVI in locations that may act as invasion hotspots. Additionally, it provides support for future policy and management measures by identifying areas that are vulnerable to biological invasions. The introduction of NIS is an important driver of changes on biodiversity, and it should be included as a key element for the creation of an integrated management tool for the Sado estuary. [ABSTRACT FROM AUTHOR]

The American brackish water mussel invaded Kerala's backwaters in 2019, and a complete eradication may not be possible at this point. Management protocols and strategies need to be developed to overcome the issue. Biological management against biofouling is a new possible approach, although it needs to be sustainable in aquaculture, where the sustainability of the method is important. The present study reports the success of a biological management strategy against biofouling of Mytella strigata by employing a native cichlid Etroplus suratensis (pearlspot), as they feed on bivalves. The study was conducted in the brackish water cage farm of a 1 ha area located at Veerampuzha backwaters, Ernakulam, in the southwest of Kerala. Pearlspot fishes were stocked inside and also in the gap between inner and outer nets of the test cages as the anti-biofouling agent. Pearlspot grew considerably by feeding on the mussel spat settled on the nets and removing a considerable amount of the fouling on the nets (287%), the increases in the average growth of seabass, in the survival rate, and in overall production of the cages. [ABSTRACT FROM AUTHOR]

Carbon nanospikes (CNSs) are a new nanomaterial that has enhanced surface roughness and surface oxide concentration, increasing the sensitivity for dopamine detection. However, CNS-modified electrodes (CNSMEs) have not been characterized for other neurochemicals, particularly those with higher oxidation potentials. The purpose of this study was to evaluate CNSMEs for the detection of adenosine, hydrogen peroxide (H2O2), and histamine. The sensitivity increased with CNSs, and signals at CNSMEs were about 3.3 times higher than CFMEs. Normalizing for surface area differences using background currents, CNSMEs show an increased signal of 4.8 times for adenosine, 1.5 times for H2O2, and 2 times for histamine. CNSMEs promoted the formation of secondary products for adenosine and histamine, which enables differentiation from other analytes with similar oxidation potentials. CNSs also selectively enhance the sensitivity for adenosine and histamine compared to H2O2. A scan rate test reveals that adenosine is more adsorption-controlled at CNS electrodes than CFMEs. CNSMEs are antifouling for histamine, with less fouling because the polymers formed after histamine electrooxidation do not adsorb due to an elevated number of edge planes. CNSMEs were useful for detecting each analyte applied in brain slices. Because of the hydrophilic surface compared to CFMEs, CNSMEs also have reduced biofouling when used in tissue. Therefore, CNSMEs are useful for tissue measurements of adenosine, hydrogen peroxide, and histamine with high selectivity and low fouling. [ABSTRACT FROM AUTHOR]

With the increasing awareness of environmental protection, it is necessary to develop natural product extracts as antifouling (AF) agents for alternatives to toxic biocides or metal-based AF paints to control biofouling. This paper briefly summarizes the latest developments in the natural product extracts and their derivatives or analogues from marine microorganisms to terrestrial plants as AF agents in the last five years. Moreover, this paper discusses the structures–activity relationship of these AF compounds and expands their AF mechanisms. Inspired by the molecular structure of natural products, some derivatives or analogues of natural product extracts and some novel strategies for improving the AF activity of protective coatings have been proposed as guidance for the development of a new generation of environmentally friendly AF agents. [ABSTRACT FROM AUTHOR]

Biofouling is the buildup of marine organisms on a submerged material. This research tests the efficacy of phosphonium ion gels comprising phosphonium monomers ([P444VB][AOT] and [P888VB][AOT]) and free ionic liquid ([P4448][AOT], [P88814][AOT]) (10 to 50 wt%), varying copper(II) oxide biocide concentrations (0 to 2 wt%), and the docusate anion [AOT]− for added hydrophobicity. The efficacy of these formulations was tested using a seachest simulator protected from light and tidal currents in New Zealand coastal waters over the summer and autumn periods. Anti-fouling performance was correlated with the hydrophobicity of the surface (water contact angle: 14–131°) and biocide concentration. Formulations with higher hydrophobicity (i.e., less free ionic liquid and longer alkyl chain substituents) displayed superior anti-fouling performance. The presence of the copper(II) biocide negatively affected anti-fouling performance via significant increases to hydrophilicity. No correlation was observed between antimicrobial activity and anti-fouling performance. Overall, phosphonium ion gels show potential for combining anti-fouling and foul release properties. [ABSTRACT FROM AUTHOR]

Biofouling is a significant problem in various industries, including marine, medical, and water treatment. It occurs when microorganisms, such as bacteria, fungi, and algae, attach to surfaces and form biofilms, which can lead to material degradation, decreased performance, and increased maintenance costs. Traditional approaches to mitigate biofouling include the use of biocides, physical cleaning, and chemical treatments. However, these methods have limitations, such as environmental concerns, short-term effectiveness, and development of resistant organisms. One alternative approach is the use of lichenassociated symbionts, which have been found to produce compounds that inhibit biofilm formation and growth. These compounds could be used to develop eco-friendly and sustainable antifouling coatings. Another promising approach is the use of nanotechnology to develop novel coatings that prevent biofouling. Nanomaterials can be engineered to have hydrophobic structures, which deter microorganisms from attaching to surfaces. They can also be designed to contain nano biocides, which can kill organisms that come into contact with the surfaces. Overall, the use of lichen-associated symbionts and nanotechnology holds great potential for developing effective and sustainable solutions to mitigate biofouling. However, further research is needed to optimize these approaches and ensure their safety and efficacy in various applications. This review offers a brief overview on the mechanisms of biofouling and evaluate the potential of using lichen-associated symbionts and nanotechnology to prevent or reduce biofouling. [ABSTRACT FROM AUTHOR]

Biofouling is a major issue in aquaculture cages and nano materials based antifouling strategies became more prominent in recent years. Polyethylene aquaculture cage net surface which is modified with polyaniline and nano-copper oxide (CuO), reported to have biofouling resistance. Leaching of nano CuO from the net to the aquatic environment and its bioaccumulation in fish is the major concern against the technology adoption. The present study aimed to understand the accumulation of copper in fishes grown in a nano CuO treated aquaculture cage net. Studied the leaching pattern of nano CuO, biofouling inhibition and changes in strength of the cage net due to the nano CuO treatments. Fishes grown in the treated cages exhibited normal growth characteristics with no signs of abnormalities and also copper in their organs were within the prescribed standard limit. The CuO treated cage net exhibited excellent biofouling resistance and the percentage of occlusion of mesh by foulers were 56.77% more efficient than untreated cage net. Rate of nano CuO leached to the aquatic system was less than 8 µg/g·d. The fouling organism assemblage on untreated and treated net was 18 and 11 species, respectively. Major calcareous shelled foulers were absent on treated nets. The study highlighted the potential application of nano CuO treatment to control biofouling in aquaculture cages. [ABSTRACT FROM AUTHOR]

Signatories to the Antarctic Treaty System’s Environmental Protocol are committed to preventing incursions of non-native species into Antarctica, but systematic surveillance is rare. Environmental DNA (eDNA) methods provide new opportunities for enhancing detection of non-native species and biosecurity monitoring. To be effective for Antarctic biosecurity, eDNA tests must have appropriate sensitivity and specificity to distinguish non-native from native Antarctic species, and be fit-for-purpose. This requires knowledge of the priority risk species or taxonomic groups for which eDNA surveillance will be informative, validated eDNA assays for those species or groups, and reference DNA sequences for both target non-native and related native Antarctic species. Here, we used an expert elicitation process and decision-by-consensus approach to identify and assess priority biosecurity risks for the Australian Antarctic Program (AAP) in East Antarctica, including identifying high priority non-native species and their potential transport pathways. We determined that the priority targets for biosecurity monitoring were not individual species, but rather broader taxonomic groups such as mussels (Mytilus species), tunicates (Ascidiacea), springtails (Collembola), and grasses (Poaceae). These groups each include multiple species with high risks of introduction to and/or establishment in Antarctica. The most appropriate eDNA methods for the AAP must be capable of detecting a range of species within these high-risk groups (e.g., eDNA metabarcoding). We conclude that the most beneficial Antarctic eDNA biosecurity applications include surveillance of marine species in nearshore environments, terrestrial invertebrates, and biofouling species on vessels visiting Antarctica. An urgent need exists to identify suitable genetic markers for detecting priority species groups, establish baseline terrestrial and marine biodiversity for Antarctic stations, and develop eDNA sampling methods for detecting biofouling organisms. [ABSTRACT FROM AUTHOR]

The ability to monitor levels of endogenous markers and clearance profiles of drugs and their metabolites can improve the quality of biomedical research and precision with which therapies are individualized. Towards this end, electrochemical aptamer-based (EAB) sensors have been developed that support the real-time monitoring of specific analytes in vivo with clinically relevant specificity and sensitivity. A challenge associated with the in vivo deployment of EAB sensors, however, is how to manage the signal drift which, although correctable, ultimately leads to unacceptably low signal-to-noise ratios, limiting the measurement duration. Motivated by the correction of signal drift, in this paper, we have explored the use of oligoethylene glycol (OEG), a widely employed antifouling coating, to reduce the signal drift in EAB sensors. Counter to expectations, however, when challenged in 37 °C whole blood in vitro , EAB sensors employing OEG-modified self-assembled monolayers exhibit both greater drift and reduced signal gain, compared with those employ a simple, hydroxyl-terminated monolayer. On the other hand, when EAB sensor was prepared with a mix monolayer using MCH and lipoamido OEG 2 alcohol, reduced signal noise was observed compared to the same sensor prepared with MCH presumably due to improved SAM construction. These results suggest broader exploration of antifouling materials will be required to improve the signal drift of EAB sensors. • Signal drift limits EAB sensor's measurement duration in vivo. • Oligoethylene glycol was employed as SAM to reduce the signal drift in EAB sensors. • In blood, EAB sensors with OEG SAM exhibit greater drift and reduced signal gain. • EAB sensor prepared with MCH and OEG mix monolayer reduced signal noise. • In vivo , drift data of mix monolayer showed similar trends. [ABSTRACT FROM AUTHOR]

Biodiversity tends to decrease poleward and increase towards the equator. However, these patterns remain unknown for many invertebrate taxa throughout Peru's eastern South Pacific coast, particularly for caprellid crustaceans which are conspicuous in artificial habitats. Three biogeographical units have been proposed for the Peruvian coast: Panamic and Humboldt provinces with a transition zone in between, but a few invertebrates support this classification. We evaluated if the diversity of caprellids decreases towards high latitudes and if the assemblages of caprellids depicted the biogeographic zonation proposed for the Peruvian coast. From 15th to 31st October 2021, caprellids were collected from biofouling communities colonizing boat hulls, buoys, and ropes throughout the Peruvian coast (3.74°–17.99° S). The caprellid assemblage consisted on six species: Caprella penantis [sensu lato], C. penantis f. gibbosa, C. equilibra, C. scaura, Paracaprella pusilla, and Deutella venenosa. Overall, caprellids' abundance, species richness, and diversity decreased southwards. Specific caprellid assemblages showed affinities for each of the three biogeographical units. The dissimilarity of the caprellid assemblages increased at approximately every one degree of latitude. Although artificial substrates can alter biodiversity patterns, caprellids showed the canonical pattern of high diversity towards the equator and resembled the biogeographic zonation proposed for the Peruvian coast. [ABSTRACT FROM AUTHOR]

Herein, we report the recent proliferation of the non-native serpulid worm Ficopomatus enigmaticus in parts of Galveston Bay, Texas. Reef-like aggregations were first recovered from a settlement plate and a submerged brick at the Kemah Boardwalk Marina on 4 May 2023. By 20 May, similar growths were reported to us by the Kemah Boardwalk Marina on floating docks, boat hulls, propellers, and rudders. On June 8, nearby marinas remained unaffected. We confirmed the worms' species identities by noting their diagnostic characteristics. [ABSTRACT FROM AUTHOR]

Congenital heart diseases (CHDs) frequently impact the right ventricular outflow tract, resulting in a significant incidence of pulmonary valve replacement in the pediatric population. While contemporary pediatric pulmonary valve replacements (PPVRs) allow satisfactory patient survival, their biocompatibility and durability remain suboptimal and repeat operations are commonplace, especially for very young patients. This places enormous physical, financial, and psychological burdens on patients and their parents, highlighting an urgent clinical need for better PPVRs. An important reason for the clinical failure of PPVRs is biofouling, which instigates various adverse biological responses such as thrombosis and infection, promoting research into various antifouling chemistries that may find utility in PPVR materials. Another significant contributor is the inevitability of somatic growth in pediatric patients, causing structural discrepancies between the patient and PPVR, stimulating the development of various growth‐accommodating heart valve prototypes. This review offers an interdisciplinary perspective on these challenges by exploring clinical experiences, physiological understandings, and bioengineering technologies that may contribute to device development. It thus aims to provide an insight into the design requirements of next‐generation PPVRs to advance clinical outcomes and promote patient quality of life. [ABSTRACT FROM AUTHOR]

Industrial cooling circuits with wet cooling towers use raw water to remove residual heat from industrial processes. These circuits are very prone to fouling and particularly biofouling. This work proposes a compartmental model built from a full hydrodynamic characterization (using computational fluid dynamics and experimental, local, and system data) of an industrial cooling circuit and implemented with a biofilm growth model which considers kinetic (temperature, concentrations) as well as hydrodynamic (internal and external transfer) limitations. It can therefore predict the biofouling growth per surface unit in the different part of the circuit, considering the various hydrodynamic conditions, while taking only a few minutes to simulate a full year considering season variation of temperature and water quality. [ABSTRACT FROM AUTHOR]

Microbial fuel cells (MFCs) use microorganisms to break down organic matter and generate power, which is an exciting new field of research. MFCs' power generation relies on oxygen reduction (ORR) at the cathode. However, the slow kinetics of the ORR can severely limit the performance of MFCs. Additionally, the growth of biofilm on the cathode hampers the ORR process. In order to ensure the sustainability of MFCs over time, it is crucial to employ bifunctional catalysts that can address these issues. Biogenic titanium dioxide (TiO2) nanoparticles (NPs) were synthesized and applied to a graphite sheet cathode in this study. Cyanobacteria, Phormidium species NCCU-104, was used to bio-fabricate titanium dioxide (TiO2) nanoparticles. NPs were characterized using SEM and TEM analysis to determine their size, shape, surface morphology, and XRD. The particles had an average size of 18.11 nm, were spherical, and were well-dispersed, according to the results of the physicochemical characterization. TiO2 NPs were evaluated in MFC using different concentrations (0.5–2.5 mg/cm2) in the cathode to generate electricity and coulombic efficiency. MFC with a cathode impregnated with 2.0 mg/cm2 TiO2 NP produced maximum power density (15.2 W/m3), which was 38% more than 0.5 mg/cm2 TiO2 NP. The overall study results indicated that biogenic TiO2 nanoparticles (NPs) could be an effective and low-cost catalyst in the oxygen reduction reaction (ORR) and significantly improve biofouling. Due to its efficient and affordable contribution to the ORR, these results imply that biogenic TiO2 NPs might be a feasible alternative for improving the performance of MFCs. [ABSTRACT FROM AUTHOR]

New composite membranes were developed and characterized for application in reverse osmosis. A commercial TFC membrane surface was modified, impregnating with Ag nanoparticles (AgNP) (5 mg, 10 mg and 15 mg per 100 mL DI water) via interfacial polymerization to improve biofouling resistance. The effects on permeate flow, operating pressure and salt rejection were assessed, with rejections of 97.6%, 97.8% and 96.7% using 5 mg, 10 mg and 15 mg, respectively. The contact angle for the 10 mg AgNP membrane (39.01 ± 4.43) showed higher hydrophilicity (> 19%) than the commercial BW30XFR membrane. Infrared spectroscopy results showed membrane modifications by signals at 1717 cm−1 and 1616 cm−1 indicating a new layer of polyamide. AFM, SEM and EDS results determined an agglomerate size for the 10 mg AgNP membrane of 3.93 µm ± 0.93 and 169.9 nm RMS roughness. The anti-biofouling properties of modified membranes were tested against Bacillus halotolerans MCC1. The results showed a highly significant reduction of biofilm cake layer, total cells, and total organic carbon on the surface of the modified membranes (72%, 48% and 45% lower) using 5 mg, 10 mg and 15 mg, respectively. [ABSTRACT FROM AUTHOR]

Developing ion‐selective membranes with anti‐biofouling property and biocompatibility is highly crucial in harvesting osmotic energy in natural environments and for future biomimetic applications. However, the exploration of membranes with these properties in osmotic energy conversion remain largely unaddressed. Herein, a tough zwitterionic gradient double‐network hydrogel membrane (ZGDHM) with excellent biofouling resistance and cytocompatibility for sustainable osmotic energy harvesting is demonstrated. The ZGDHM, composed of negatively charged 2‐acrylamido‐2‐methylpropanesulfonic acid (AMPS) as the first scaffold network and zwitterionic sulfobetaine acrylamide (SBAA) as the second network, is prepared by a two‐step photopolymerization, thus creating continuous gradient double‐network nanoarchitecture and then remarkably enhanced mechanical properties. As verified by the experiments and simulations, the gradient nanoarchitecture endows the hydrogel membrane with apparent ionic diode effect and space‐charge‐governed transport property, thus facilitating directional ion transport. Consequently, the ZGDHM can achieve a power density of 5.44 W m−2 by mixing artificial seawater and river water, surpassing the commercial benchmark. Most importantly, the output power can be promoted to an unprecedented value of 49.6 W m−2 at the mixing of salt‐lake water and river water, nearly doubling up most of the existing nanofluidic membranes. This study paves a new avenue toward developing ultrahigh‐performance osmotic energy harvesters for biomimetic applications. [ABSTRACT FROM AUTHOR]