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Antifouling paint was introduced and utilized as a control to prevent the problem of biofouling. The Methanolic Crude Extract (MCE) and the Essential Oil (EO) were extracted from Melaleuca cajuputi. Gas Chromatography-Mass Spectrometry (GC-MS) was used to determine the metabolite profiles. An antibacterial assay was conducted via the disc diffusion technique and an antifouling assay of MCE and EO of M. cajuputi was investigated using a crystal violet assay and painted steel panels incorporating MCE and EO. Painted steel panels were immersed in the aquarium to measure the antibiofilm activity and in the natural sea environment to observe the settlement of foulers. The MCE exhibits antibacterial activity against Gram-negative bacteria, indicating narrow-spectrum activity, while EO has broad-spectrum activity against Gram-positive and −negative bacteria. The GC-MS profile showed the presence of cycloheptasiloxane, tetradecamethyl-, cyclotrisiloxane, hexamethyl-, terpinene-4-ol, caryophyllene, and 1,8-cineole in both MCE and EO of M. cajuputi. Crystal violet assay revealed that both samples reduced the attachment of biofilm form by Pseudomonas aeruginosa at 61% and 60%. Panel painted with paint incorporated 5% MCE inhibits bacteria growth in natural seawater, followed by 10% MCE, 5% EO, and 10% EO in aquarium testing. Referring to photographic observation, all the panels coated with paint incorporated with samples successfully reduced the attachment of foulers compared to Blank Paint (BP). In conclusion, these findings indicated that the MCE and EO of M. cajuputi could potentially be used as a substitute for toxic antifoulants to prevent the formation of microfoulers. [ABSTRACT FROM AUTHOR]

Discovering macromolecules and understanding the associated mechanisms involved in underwater adhesion are essential for both studying the fundamental ecology of benthos in aquatic ecosystems and developing biomimetic adhesive materials in industries. Here, we employed quantitative proteomics to assess protein expression variations during the development of the distinct adhesive structure - stolon in the model fouling ascidian, Ciona robusta. We found 16 adhesive protein candidates with increased expression in the stolon, with ascidian adhesive protein 1 (AAP1) being particularly rich in adhesion-related signal peptides, amino acids, and functional domains. Western blot and immunolocalization analyses confirmed the prominent AAP1 signals in the mantle, tunic, stolon, and adhesive footprints, indicating the interfacial role of this protein. Surface coating and atomic force microscopy experiments verified AAP1′s adhesion to diverse materials, likely through the specific electrostatic and hydrophobic amino acid interactions with various substrates. In addition, molecular docking calculations indicated the AAP1′s potential for cross-linking via hydrogen bonds and salt bridges among Von Willebrand factor type A domains, enhancing its adhesion capability. Altogether, the newly discovered interfacial protein responsible for permanent underwater adhesion, along with the elucidated adhesion mechanisms, are expected to contribute to the development of biomimetic adhesive materials and anti-fouling strategies. Discovering macromolecules and studying their associated mechanisms involved in underwater adhesion are essential for understanding the fundamental ecology of benthos in aquatic ecosystems and developing innovative bionic adhesive materials in various industries. Using multidisciplinary analytical methods, we identified an interfacial protein - Ascidian Adhesive Protein 1 (AAP1) from the model marine fouling ascidian, Ciona robusta. The interfacial functions of AAP1 are achieved by electrostatic and hydrophobic interactions, and the Von Willebrand factor type A domain-based cross-linking likely enhances AAP1's interfacial adhesion. The identification and validation of the interfacial functions of AAP1, combined with the elucidation of adhesion mechanisms, present a promising target for the development of biomimetic adhesive materials and the formulation of effective anti-fouling strategies. [Display omitted] [ABSTRACT FROM AUTHOR]

Understanding how to control microorganisms in source water and during treatment can help operators suppress microbial proliferation in distribution systems and prevent customer complaints. [ABSTRACT FROM AUTHOR]

The submerged surfaces of boats act as microbial seed banks which introduce non-indigenous microbial strains in the marine habitat. This study focuses on the morphological, biochemical and molecular characterisation of bacteria isolated from water and submerged painted boat hulls in Badagry lagoon, Lagos state, Nigeria using standard techniques. The mean bacterial density obtained were 1.9 x 109 CFU/mL and 2.03 x 104 CFU/g for water samples and hull samples respectively. Morphological, biochemical and molecular characterisation confirmed the bacteria to be Bacillus subtilis, B. flexus, B. cereus, Brevibacillus agri, Aeromonas punctata, Staphylococcus sciuri, B. licheniformis, Kurthia gibsonii and Leclercia adecarboxylata. Results of the study showed that some of the isolates (B. cereus, B. flexus, S. sciuri and L. adecarboxylata) are pathogenic while others (B. agri and A. punctate) are opportunistic pathogens. The proportion of pathogenic strains isolated in this study is greater than the non-pathogenic strains. [ABSTRACT FROM AUTHOR]

A considerable hindrance in application of ultrafiltration membranes for aqueous application is an occurring fouling which promotes deterioration of the membrane separation processes. Natural Olea europaea leaves extract nanosolids embed in cellulose acetate polymer matrix to enhance anti-biofouling properties of ultrafiltration membrane. Olea europaea phenolic compounds extracted by using Microwave-assisted Extraction (MAE) method and evaporated to obtain nanosolid particles. The cellulose acetate/ Olea europaea nanosolids (CA/OEN) membrane composite prepared using phase inversion method. The membrane properties evaluated in term of mechanical, mass transport and anti-biofouling properties. The membranes show a good mechanical property with the membrane tensile ranged within 3.3 N/mm2 and 6.8 N/mm2, and can acts as ultrafiltration composite membranes based on the pure water transport across the membrane, with the pure water flux ranged from 0.3 L/m2.h.bar to 0.9 L/m2.h.bar. In term of anti-biofouling properties, the membrane shows a good anti-biofouling property against Escherichia coli, Bacillus subtilis , and Staphylococcus aureus , with the percentage of area covered by bacteria are ranged between 0.39 % and 1.41 %. Yet, penetration of phenolic substance into bacterial cells could effectively occurred in a Gram-negative bacterium such as Escherichia coli due to low affinity, thin cell wall, and few peptidoglycans structure. [ABSTRACT FROM AUTHOR]

The feasibility of the ultraviolet germicidal irradiation (UVGI) application has been proven over the past few decades, especially in disinfection performances; however, a small number of studies were found that explored the energy efficiency improvement and cost savings of real buildings by implementing the UVC systems on cooling coils. The goal of this study is to verify the energy efficiency improvements and cost savings of AHU in a real building environment by removing biofilms on the cooling coil surfaces with the UVC irradiation techniques that can provide higher lamp output (300 μW/cm2) as well as higher intensity levels (1000–4000 μW/cm2) on the cooling coil surfaces. A series of experiments were conducted in an AHU in a medical center located in Michigan, US, to estimate energy efficiency improvement of cooling coils, chiller, and fan with UVC application. The results show that after 7 weeks of UVC operation increased coil overall enthalpy-based thermal conductance by 15.62 %, achieved chiller-side energy savings by up to 28.2 %, reduced pump energy by 32.1 %, and fan energy by 17.7 %. A return on investment (ROI) based only on energy savings is estimated to be 43 % and has a payback period of 2.32 years. When the labor, chemical, and water-saving costs for coil cleaning were included, the ROI was increased to 49 % and reduced the payback period to 2.04 years. When it comes to UVC's disinfection performances, six pathogens showed a more than 99 % removal rate while Klebsiella pneumoniae and Clostridium difficile showed a relatively lower 94 % removal rate. • AHUS's energy efficiency improvement was tested with high-intensity profile UVC irradiation systems. • Overall enthalpy-based thermal conductance of the cooling coil was improved by 15.62 %. • Chiller-side energy savings were achieved by up to 28.2 % after 7 weeks of UVC operation. • Distribution energy was saved by reducing pressured drop and increasing heat transfer rate within AHU. • A return on investment is estimated to be 43 % which resulted in a payback period of 2.32 years. [ABSTRACT FROM AUTHOR]

Marine biofouling is considered one of the major biophysical processes influencing the vertical dynamics of plastic debris in seawater. We numerically implement, for the first time, this mechanism within a fine-resolution, regional model of the Tyrrhenian Sea, in order to simulate the dispersion of microplastics (MPs) released at the mouth of a highly polluting river. Four polymers and three particle sizes are used to quantify algal concentration influence on the trajectories, fates, and accumulation spots of the tracked MPs, by comparing 2002 winter and summer runs encompassing or not biofouling. Besides a marked seasonality for most of the MP types and radii tested, biofouling effects are prominently observed for only 2 polymers and particles bigger than 1 μ m. Thus, further realistic applications of the biofouling mechanism in oceanic circulation models are required to achieve a thorough assessment of its impact on plastic density within distinctive basins of the world seas. • Marine biofouling is explicitly resolved in a realistic regional model (ROMS). • Microplastic (MP) particles are released at the outlet of a highly polluted river. • Biofouling strongly affects the horizontal and vertical dispersion of MPs. • Biofouling effects are significant for a limited range of MPs' sizes and polymers. • A marked seasonality is observed in the biofilm growth over the MP particles. [Display omitted] [ABSTRACT FROM AUTHOR]

The aim of this paper is to characterize the plastic and to study a potential relationship between plastic debris characteristics and the presence of fouling biota in an Antarctic Specially Protected Area Robert Island, on the Antarctic peninsula region. A combination of lab-based sorting, advanced spectral analysis and general linear modelling was used to assess the abundance and type of plastic debris washed up on the shore. Observations recorded 730 debris items, with 85 % being plastic. Polystyrene (PS) and Polyethylene terephthalate (PET) were the dominant plastics (61 %). Biofouling was observed on 25 % of plastic debris, with debris complexity and degradation significantly increasing the likelihood of fouling occurring. There was no correlation found between biofouling type and plastic polymer type. Findings raise concerns that even with the highest level of environmental protection, an external marine-based source of pollution can intrude the coastal habitat, with uncertain consequences to local flora and fauna. [Display omitted] • 730 debris items were collected, of which 621 (85%) were plastic. • 53.4% of the plastic was fishing gear (39 kg), while consumer products accounted for 15% (20 kg). • Polystyrene (PS) and Polyethylene terephthalate (PET) were the dominant plastics (61%). • Biofouling was present on 25.3% of the collected plastic. • Complexity and high levels of degradation increase the presence of fouling biota on plastics. [ABSTRACT FROM AUTHOR]

The reverse osmosis seawater desalination plants open-intake requires different strategies of pre-treatment to reduce the biofouling and scaling. The UltraFiltration (UF) technology is a recent application to this process. In this work, some alternatives to chemical products reducing in chemically enhanced backwash (CEB) and clean in place (CIP) of a UF rack have been studied. Mainly the sodium hypochlorite consumption, due to its biofouling precursor effect over reverse osmosis membranes. For this purpose, the optimal filtration time has been studied, to get the highest water production prior to the CIP, as well as some modifications in the conventional CIP's, modifying the duration of the stages of the same. The results were compared with the current mode of daily operation of the CEB. The results show that a reduction of up to 60% in the amount of sodium hypochlorite per cubic meter of water produced employed in UF CEB's, mini CIP's and CIP's can be achieved. However, the consumption of the rest of chemical dosing increased notably, and therefore the operating cost of UF also increased. In addition, there was an increase of desalted water consumption to the chemical products removed, up to almost 95,84 %, in comparison with the currently operational mode of CEB. On the other hand, operating the UF plant in the manner proposed requires a automatization of the process and expert staff to programme the control. Therefore, based on the results obtained, the alternatives proposed could reduce the chemical products in use, but it is not conclusive in terms of exploitation operational costs. [ABSTRACT FROM AUTHOR]

Studies in the oceans and The Great Lakes have found several orders of magnitude less plastic in surface samples than predicted by input estimates. Some plastic likely sinks after entering the water because it is naturally more dense than freshwater. For less dense particles, it has been proposed that biofouling, or the buildup of organic materials on the plastic, can cause them to become more dense and ultimately induce sinking. In this work we compare two different functional biofouling models: one basic algal growth population model and one model that assumes photosensitive defouling. We investigate the effects within the scope of a large-scale hydrodynamic model that includes advection, vertical diffusion, and sediment deposition applied to both Lake Erie and Lake Ontario. We find that deposition rates are dependent on the fouling method and lake depth. Lastly, we use the model to develop a first pass mass estimate for the sediment deposition rate in Lake Ontario. [ABSTRACT FROM AUTHOR]

Maritime industries are constantly searching for a method to enhance ship efficiency, with increasing concern about the environmental impact and rising fuel prices. Marine biofouling is one of the factors that increase ship fuel consumption. However, removing the fouling of the ship requires effort for hull maintenance. Due to the trade-off between conducting maintenance and performance degradation, this study presents the development of a Model-Driven Decision Support System (MD-DSS) to predict the optimum time for underwater hull cleaning for biofouling management. Five stages (sub-models) are employed to develop a DSS, namely: ship resistance estimation, estimation of additional resistance due to biofouling, an iterative-based method for determining the best time to conduct the hull cleaning, and an analysis report. The implemented algorithm was validated by comparing its result with a manually scheduled maintenance date. The DSS is able to determine the best time (date) for maintenance in all given scenarios. By giving two scenarios of different maintenance costs and different fuel prices, the optimisation results produce the same number of maintenances. Within 60 months, four to five hull cleanings are required. It is also found that when the optimal number of maintenances is known, then increasing this number will not have any impact on reducing the hull cleaning costs because the reduction in fouling does not significantly reduce the costs incurred for maintenance. During several trials of the DSS, it is shown that the system can generate maintenance schedules for different time intervals of ship operation within an acceptable time. It takes approximately 52 minutes, 12 minutes, and 5 minutes consecutively to determine the maintenance schedules for ship operation intervals of 5 years, 2.5 years, and 1 year. [ABSTRACT FROM AUTHOR]

The accumulation of organisms on submersed objects, so-called biofouling, is a serious problem on technically relevant surfaces and causes enormous economic damage. In the case of shipping, it also leads to increased fuel consumption and therefore also to elevated CO2 emissions. Within the context of this work, an experimental setup was built to achieve laser-induced lethal damage to soft fouling microorganisms. At the same time, the influence of this laser treatment on two commercial anti-fouling coatings was evaluated by determining the destruction thresholds and the reflection properties of the coatings. The results show that a cleaning effect of the biofouling can be achieved by laser treatment. [ABSTRACT FROM AUTHOR]

Biofouling represents a global challenge for the maritime industry, affecting vessel performance and environmental footprint. This paper analyses various antifouling technologies to reduce the vessel's environmental impact and its operating costs by reduced fuel consumption and less frequent dry-docking. It evaluates both passive and active technologies – passive referring to antifouling coatings and active involving systems that continuously prevent biofouling using energy. The methodology employs mathematical models to quantify the additional resistance and emissions caused by biofouling. Using the case of a fishing vessel operating in the Adriatic Sea, operational features and potential economic and environmental benefits resulting implementing an innovative biofouling protection system are analysed. Economic analysis includes a comprehensive cost structure, investment details, maintenance and operating costs, and possible future carbon taxation scenarios. The research indicates that active antifouling protection is more efficient than passive protection, including a potential reduction of the required power of up to 120 kW, leading to decreased fuel consumption and lower environmental impact, particularly at higher speeds. Despite higher initial investments, life-cycle cost analysis favours active protection systems. • LCCA of different antifouling techniques has been performed • Active antifouling protection is more efficient compared to passive in the lifetime framework • Effect of hull protection is more pronounced at higher speeds • Implementation of carbon tax emphasizes advantages and importance of hull maintenance [ABSTRACT FROM AUTHOR]

Biodegradable microplastics (MPs) can form biofilms through interactions with various microorganisms in aquatic system and can be exposed to organisms. This study first investigated biodegradability of polylactic acid (PLA) MPs and the characterization of PLA MPs before/after biofouling (4 weeks) and their toxic effects on the freshwater invertebrate Daphnia magna. The biodegradability rate of PLA MPs was up to 50% over 28 days, suggesting that even biodegradable MPs do not easily decompose under environmental conditions. Furthermore, biofouling of MPs led to an increase in size and, in the process, induced an additional functional peak in the PLA MPs. The exposure of biofouled MPs did not lead to a reduction in survival, reproduction, or growth during chronic exposure, nor did it cause feeding inhibition in juvenile (<4 days old) D. magna. However, pristine MPs significantly reduced survival, reproduction, and growth at concentrations of 5.0 mg L−1. Overall, pristine MPs caused inhibition of reproduction and growth and high mortality in D. magna , while the biofouling process did not induce these effects. Our findings highlight the complex interactions between MPs and biological components in aquatic environments, emphasizing the importance of considering biofouling dynamics when assessing the ecological impacts of biodegradable MPs. [Display omitted] • Pristine PLA MPs are not readily biodegradable within 28 days in aquatic environments. • Biofouling in WWTP sludge over 28 days led to the aggregation and increased size of PLA MPs. • The toxicity of Biofouled PLA MPs lower than pristine PLA MPs over a chronic exposure. • Biofouled PLA MPs do not induce oxidative stress to D. magna over a chronic exposure. [ABSTRACT FROM AUTHOR]

Various anthropogenic activities affect marine coastal habitats, leading to heavy litter pollution. However, whilst high litter concentrations are nowadays common in the proximity of metropolises, few studies investigated the magnitude of this phenomenon around coastal villages and small towns. We hereby characterized the benthic litter occurring in the trawlable grounds of the Gulf of Policastro (Tyrrhenian Sea, central-western Mediterranean), a low population density area that becomes a popular tourist destination during summer. We furthermore tested differences between two depths (∼100–200 and ∼500–600 m) and the impact of tourism on the shallower waters. The area was characterized by a litter abundance of 651.12 ± 130.61 item/km2, with plastic being almost totalitarian (93%). The shallower waters hosted two-thirds of the litter found. Almost all (∼95%) the litter items had a land-based origin, while the sea-based litter was mostly found at higher depths. About 14% of the litter was found to be fouled, with the development of litter-associated communities that somehow mimic the natural ones living on hard substrates. The higher litter presence noticed during the touristic peak (July–August) suggests that tourism is an important source of local litter, although it contributed to the local accumulation in a synergic way with other factors. The majority of the litter items presumably originated from the nearby coastline, while the deeper waters were or are used as a dumping site by the local trawling fleet. The discovery of such a critical waste accumulation and management in a somehow remote area contributes to widen the perspectives on the presence of benthic litter mostly in territories characterized by wide anthropization. Moreover, it confirms that appropriate local policies and communication plans are urged even at a regional level to stimulate citizen consciousness and mitigate the ever growing litter pollution. [Display omitted] • A high amount of benthic litter was found in a low population density area. • The majority of the litter originated from the nearby coastline. • Deeper waters were or are used as a dumping site by the local trawling fleet. • Summer tourism strongly contributed to litter accumulation in shallow waters. • Local policies and communication plans are urged even at a regional level. [ABSTRACT FROM AUTHOR]

Marine biofouling remains a huge concern for maritime industries and for environmental health. Although the current biocide-based antifouling coatings can prevent marine biofouling, their use has been associated with toxicity for the marine environment, being urgent to find sustainable alternatives. Previously, our research group has identified a prenylated chalcone (1) with promising antifouling activity against the settlement of larvae of the macrofouling species Mytilus galloprovincialis (EC 50 = 16.48 µM and LC 50 > 200 µM) and lower ecotoxicity when compared to Econea®, a commercial antifouling agent in use. Herein, a series of chalcone 1 analogues were designed and synthesized in order to obtain optimized antifouling compounds with improved potency while maintaining low ecotoxicity. Compounds 8 , 15 , 24 , and 27 showed promising antifouling activity against the settlement of M. galloprovincialis larvae, being dihydrochalcone 27 the most potent. The effect of compound 24 was associated with the inhibition of acetylcholinesterase activity. Among the synthesized compounds, compound 24 also showed potent complementary activity against Navicula sp. (EC 50 = 4.86 µM), similarly to the lead chalcone 1 (EC 50 = 6.75 µM). Regarding the structure-activity relationship, the overall results demonstrate that the substitution of the chalcone of the lead compound 1 by a dihydrochalcone scaffold resulted in an optimized potency against the settlement of mussel larvae. Marine polyurethane (PU)-based coatings containing the best performed compound concerning anti-settlement activity (dihydrochalcone 27) were prepared, and mussel larvae adherence was reduced compared to control PU coatings. [Display omitted] • Flavonoids 8, 14, 24 and 27 with antifouling activity and low toxicity were obtained. • Compound 27 inhibited mussel settlement with an EC50 lower than compound 1. • Compound 24 inhibited the growth of marine diatom Navicula sp. (EC50: 4.86 µM). • Compounds 15, 24 and 27 were non-toxic against the non-target species Artemia salina. • Compound 27-based coating was effective in preventing mussel settlement. [ABSTRACT FROM AUTHOR]

Oysters are widespread throughout the intertidal regions, and accurate identification and monitoring of their ecological status are still difficult due to their high level of plasticity. Anthropogenic activities facilitate oyster dispersal to new habitats through the shipping and elimination of existing barriers. In this study, a combination of morphological and molecular techniques was used to clarify the identity of an oyster species occurring along the Iranian coast of the Persian Gulf. Specimens were collected from the jetties of the ports and the rocky shores along the northern Persian Gulf. Oyster identification was carried out to the lowest possible taxonomic level based on shell morphology. The phylogenetic analysis was done using the cytochrome c oxidase subunit 1 (COI) fragments. Morphological results confirmed that studied samples belong to the genus Crassostrea and showed close to the Vietnamese (Crassostrea markushuberi) species. Molecular analysis reveals that species are a sister species to a clade containing Crassostrea zhanjiangensis and Crassostrea talonata. According to the relatively high genetic distances and lack of similarity in shell characteristics, the species is considered as distant sister species of C. zhanjiangensis and C. talonata. The results showed a non-native small size of oyster in the northern Persian Gulf, which might be a new species. The relative abundance of this species in the introduced location (Imam Khomeini port) may be linked to the high adaptation capability to the new environment. [ABSTRACT FROM AUTHOR]

• The non-bactericidal films have durable antifouling ability in natural marine environment for 9 months. • Although bactericidal films have anti-adhesion effect under laboratory conditions, but the anti-adhesion effect is not durable. • GSR has lower elastic modulus and compression modulus, which is beneficial to inhibiting bacterial adhesion. Marine biofouling has done great economic damage to people every year, and it seriously affects the development of national economy. In this paper, three types of antifouling films were prepared, including pristine silicon rubber (PSR), graphene added silicon rubber (GSR), and GSR filled with quaternary ammonium salt of different concentrations (QGSR). These antifouling films have strong salt resistance ability, and their surface free energy is in the range of 19.3078 mJ/m2–21.4384 mJ/m2, which is calculated by contact angle. Based on Baier curve, the surface free energy in this zone is benefit to fouling-release. Then, the antifouling ability were explored under both laboratory conditions and real marine environments. Results showed that the bactericidal film of QGSR have antiadhesion effect under laboratory conditions, but the antiadhesion effect is not durable, and it lose antifouling effects completely in real marine conditions. However, the non-bactericidal film of GSR exhibited stronger antifouling ability than QGSR after immersed in marine environment for 9 months. Therefore, the physical interaction to expel bacteria is more conducive to long-term antifouling in the complex marine environment. [Display omitted] [ABSTRACT FROM AUTHOR]

Composition, and density of marine litter and associated macrofouling organisms was assessed in the continental shelf of the Northeastern Mediterranean Sea. A total of 943 litter items weighing 388 kg were collected during 34 hauls. Plastic comprised 72 % of the total litter found on the seafloor. The mean number and weight of ML was 4241 ± 1333 items/km2 and 368 ± 87 kg/km2. Depth and distance from the shore were not identified as a significant factor affecting both the number and weight of litter. A total of 20 fouling species and eggs belonging to Mollusca, Porifera, Cnidaria, Bryozoa, Annelida, Arthropoda, and Chordata were found on marine litter. An alien Mollusca species Pinctada imbricate was also found on plastic litter. Our results confirmed that marine litter is a vector transporting a variety of organisms including alien species and being a threat for the biodiversity and human health in the Mediterranean Sea. • Seafloor litter and associated macrofouling organisms was assessed in the NE Mediterranean Sea. • Plastics comprised 72 % of the total litter found on the seafloor. • Species belonging to Mollusca, Porifera, Cnidaria, Bryozoa, Annelida, Arthropoda, and Chordata were found on seafloor litter. • An alien Mollusca species Pinctada imbricate was also found on plastic litter. • Depth and distance from the shore were not affect the sea floor litter distribution. [ABSTRACT FROM AUTHOR]

Calcium ion (Ca2+) is involved in the protein-mediated larval adhesion of fouling ascidians, yet the effects of environmental Ca2+ on larval adhesion remain largely unexplored. Here, the larvae of fouling ascidian C. robusta were exposed to different concentrations of Ca2+. Exposures to low-concentration (0 mM and 5 mM) and high-concentration (20 mM and 40 mM) Ca2+ significantly decreased the adhesion rate of larvae, which was primarily attributed to the decreases in adhesive structure length and curvature. Changes in the expressions of genes encoding adhesion-, microvilli-, muscle contraction-, and collagen-related proteins provided a molecular-level explanation for adhesion rate reduction. Additionally, larvae likely prioritized their energy towards immunomodulation in response to Ca2+ stresses, ultimately leading to adhesion reduction. These findings advance our understanding of the influencing mechanisms of environmental Ca2+ on larval adhesion, which are expected to provide references for the development of precise antifouling strategies against ascidians and other fouling species. [Display omitted] • Exposures to high- and low-concentrations of Ca2+ reduced larval adhesion rate. • Adhesive structure changes attributed to the reduction in adhesion rate. • Expression changes of adhesion-related genes explained adhesion reduction. • Collagen, microvilli, and muscle-related genes were related to adhesion reduction. • Larvae prioritized energy towards immunomodulation, leading to adhesion reduction. [ABSTRACT FROM AUTHOR]

The recreational boating sector is a major vector for the introduction of non-indigenous species (NIS) via biofouling. Despite applying control measures to prevent the growth of fouling communities, most vessels are NIS carriers. This study assessed the effectiveness of different antifouling strategies in a manipulative experiment by testing two common coating typologies (biocide-based and foul-release coatings), accompanied with simulated maintenance practices. The experiment was carried out in the Gulf of La Spezia (Italy) and samples were collected at two different periods. Results showed significant differences among antifouling treatments regarding community structure, diversity, coverage and biovolume of the sessile component, alongside a significant decrease in the performance of biocide-based coating with time. Interestingly, peracarid NIS/native species ratio was higher for biocide-based treatments, suggesting potential biocide resistance. This study highlights the urgent need to develop common and feasible biofouling management plans and provides insights towards identification of best practices for recreational vessels. [Display omitted] • Biocide-based coating's performance drops before reaching half of its service life. • Foul-release coating shows self-cleaning evidences in stationary conditions. • A few non-indigenous and cryptogenic species show tolerance to biocides. • The work provides evidence to be considered for biofouling management plans. [ABSTRACT FROM AUTHOR]

A proof-of-concept study was designed to investigate using an Ultraviolet C (UVC) lamp mounted on a hull-crawling remotely operated vehicle (ROV) to prevent biofouling on a ship hull. A wheeled cart with a UVC lamp was built to expose two large test panels to UVC. The test panels were coated with an ablative copper antifouling and a silicone fouling release coating, and these were immersed in seawater at Port Canaveral, Florida. Three exposure frequencies (once a week, twice a week, and three times a week) and two dosages (8 and 16 s of UVC exposure) were tested. UVC was effective at preventing biofilm growth during the first 2 weeks of UVC treatment but was unable to prevent increased fouling growth as time progressed. It appears that an increase in UVC intensity and duration of exposure would be needed to prevent fouling growth especially during high-fouling seasons or that UVC exposure would need to be combined with another fouling prevention practice, such as mechanical wiping, to be more effective. [ABSTRACT FROM AUTHOR]

This study investigates in detail species diversity of cyanobacteria which proliferated on the surface of diseased sponges and bedrock in Lake Baikal (Siberia, Russia) during the ecological crisis that has been progressing in the littoral zone since 2011 and caused numerous negative changes in biota. In 2014–2015, we examined samples from diseased and healthy sponges as well as rock substrates using Sanger sequencing and high-throughput 16S rRNA gene analysis. Based on morphology, we identified 15 cyanobacterial species in biofoulings. Tychonema sp., Symplocastrum sp., Pseudanabaena galeata and Tolypothrix distorta dominated on diseased sponges. In communities of healthy sponges, we detected mainly picocyanobacteria Synechococcus. Fascicles of Symplocastrum sp. and T. distorta dominated on bedrock substrates. Phylogenetically, most 16S rDNAs clustered among Tychonema , Pseudanabaena , Geitlerinema , Kamptonema , Leptolyngbya , and Tolypothrix spp. Cyanobacterial proliferation in the littoral zone of Lake Baikal should be considered as one of the most important negative ecological processes in recent times which requires an urgent study in order to understand the causes of its emergence and development. Mat-forming cyanobacteria Tychonema characterized by the highest tropism to sponges plays a special role in the disease and death of sponges. [ABSTRACT FROM AUTHOR]

Biofouling in cage aquaculture netting causes clogging of meshes, increased stress and retards the growth of fishes. This paper describes a new method of protecting polyethylene cage nettings from biofouling using polyaniline and nano-copper oxide. Polyaniline was synthesized in-situ over polyethylene cage netting material and subsequently treated with nano copper oxide. The modified netting material exposed to estuarine environment exhibited excellent fouling resistance. FTIR characterization confirmed the formation of polyaniline and adsorption of nano copper oxide over the netting material. SEM and AFM evaluation showed uniform coating of polyaniline and nano copper oxide on the polyethylene-polyaniline (PE-PANI) matrix. The results highlight the potential application of polyaniline plus nano copper oxide coated polyethylene nettings in controlling biofouling in cage aquaculture. [ABSTRACT FROM AUTHOR]

The development of biofouling mitigation and cleaning strategy is of paramount importance for ultrafiltration (UF) membrane biofouling. In this study, polyethersulfone (PES) UF membrane was functionalized, namely MoS 2 /PES composite membrane. The MoS 2 /PES composite membrane exhibited superior antifouling property as evidenced by antibacterial circle, static and dynamic biofouling experiments. The permeate fluxes of the pristine PES and MoS 2 /PES composite membrane respectively decreased by 76% and 31% at the end of 3-h filtration. After exposure of E. coli to MoS 2 , inhibited cell growth led to reduced membrane biofouling. The biofilm formation was retarded under the dynamic flow condition, which were further confirmed by Scanning Electron Microscopy (SEM) and Confocal Laser Scanning Microscopy (CLSM) observations. As for the enhanced biofouling removal by cleaning with H 2 O 2 , 62% of the flux recovery rate for the MoS 2 /PES composite membrane was much higher than the pristine PES membrane (24%). The peroxidase-like properties of MoS 2 were responsible for the enhancement of the superior cleaning performance. The use of H 2 O 2 to trigger the in-situ catalytic function of the MoS 2 nano-enzyme generated more ROS and O 2 for inducing bacterial cells death and facilitating detachment of biofilm. This work will be helpful to provide important insights into developing more effective strategies for biofouling control and cleaning using advanced nanomaterials in membrane-based water treatment processes. [Display omitted] • Antibiofouling PES UF membranes functionalized with MoS 2 nanosheets was synthesized. • Oxidative stress and physical damage were mainly responsible for high antibacterial activity. • Self-cleaning with H 2 O 2 solution to remove biofouling of MoS 2 /PES membrane was achieved. • Self-cleaning was attributed to ROS and O 2 gas produced between H 2 O 2 and MoS 2 /PES membrane. [ABSTRACT FROM AUTHOR]

Microfiltration membrane separation is widely applied for water and wastewater but biofouling is a challenging task in real applications. In this work, we fabricated a novel antibiofouling polyvinylidene fluoride (PVDF) membrane by grafting non-drug-resistant antimicrobial peptides (AMPs) on the membranes via 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride/ N -hydroxy sulfosuccinimide (EDC/Sulfo-NHS) chemistry. Effects of AMPs concentration on the membrane basic properties, antibacterial and antibiofouling behaviors of the modified membranes were systematically investigated. Membrane surface characterization demonstrated that the AMPs were successfully grafted onto the base PVDF membranes. The AMPs modified membrane showed enhanced hydrophilicity, consistent permeability and prominent antimicrobial ability (i.e., >90% of antibacterial efficiency against both Escherichia coli and Staphylococcus aureus). Batch filtration tests exhibited that the modified membranes with the concentration of AMPs less than or equal to 0.7 mg/mL had lower flux decline rate compared to the pristine membrane (M0). According to the images from confocal laser scanning microscopy analysis, less total cells as well as more dead cells were observed on the AMPs modified membrane compared to M0. Furthermore, the grafted AMPs on the membranes also displayed favorable stability suffered from a cycle involving biofouling and chemical cleaning. This grafting protocol for AMPs highlights a robust way to fabricate antibiofouling membranes for water and wastewater treatment. [Display omitted] • Grafting antimicrobial peptides (AMPs) on a membrane for biofouling mitigation. • AMPs grafted membranes showed antibacterial effects against S. aureus and E. coli. • AMPs grafted membranes demonstrated compelling antibiofouling performance. • AMPs grafted membranes exhibited favorable stability after chemical cleaning. • It provides a new way to fabricate antibiofouling membranes for water treatment. [ABSTRACT FROM AUTHOR]

Following the Editorial addressing the BALMAS project, we open the ballast water management special issue for the Adriatic Sea by providing background information on non-indigenous species and the mechanisms (vectors) of transport. Problems allocating introduction mechanisms for various species with certainty are described; in general, key introduction mechanisms are shipping, with ballast water and biofouling as dominant vectors, and aquaculture activities. The dominant mechanisms for introduction may differ through time, between regions and across species. We highlight ballast water as the focus of an international convention to prevent future introductions, reviewing management options and suggesting future research needs. This assessment is not restricted in application to the Adriatic Sea, but is applicable to other coastal waters. Results of such future work may contribute to the experience building phase planned by the International Maritime Organization for a harmonised implementation of the Ballast Water Management Convention. Unlabelled Image [ABSTRACT FROM AUTHOR]

The microbial corrosion behaviour of nickel-phosphorus (Ni-P) by Desulfovibrio desulfuricans (SRB, ATCC 7757) was investigated experimentally. The colonization of SRB on Ni-P surface was observed by fluorescence microscope (FM) and scanning electron microscope (SEM). The corrosion of Ni-P plating was studied by electrochemical impedance spectroscopy (EIS). The results indicate corrosion aggravated from 1 d to 7 d and then slowed down after 7 d. The corrosion products were analyzed by Energy Dispersive X-ray (EDX) spectra. The corrosion of Ni-P in SRB medium was more deteriorative than the control group. Accordingly, the corrosion process was accelerated in the presence of SRB and its extracellular polymeric substance (EPS). The EIS data of Ni-P plating were fitted to equivalent circuits. The results show that the resistance of charge transfer on Ni-P surface increased quickly from 1 d to 7 d and then decreased to 22.4 kΩ·cm−2 finally. [ABSTRACT FROM AUTHOR]

Barnacles are sessile organisms globally distributed in marine and estuarine environments. The production of protein-based adhesives by cement glands is crucial for these organisms and plays a vital role in substrate attachment, thus inspiring biotechnological applications. Moreover, barnacles belong to bio-fouling communities, whose fixation onto man-made surfaces is of interest in terms of control and imposes an enormous economic cost on maritime industries. Here, we generated the first de novo assembly of cement gland transcriptomes of Pollicipes pollicipes (rocky-shore goose barnacle) and Lepas anatifera (pelagic goose barnacle) (Cirripedia, Thoracica), to generate molecular resources for understanding the bio-adhesion process in Cirripedia and to provide data for biotechnology. Via the Illumina next-generation sequencing technology, a total of 43.7 and 40.2 million (M) paired-end (PE) clean reads were obtained for P. pollicipes (PP) and L. anatifera (LA), respectively. De novo assemblies resulted in 116,377 transcripts for PP and 94,143 for LA, with N50 s of 1181 and 1028 bp, respectively. The Benchmarking Universal Single-Copy Orthologs (BUSCO) showed 78.7% (PP) and 91.7% (LA) of transcriptome completeness, in terms of expected gene content, for the Arthropoda phylum in each species. These results represent a substantial resource for expanding the knowledge on Cirripedia adhesion mechanisms and for contributions to the gene annotation of Crustacea where molecular resources are presently insufficient. [ABSTRACT FROM AUTHOR]

Abstract Fouling species display characteristics that make them suitable options for bioremediation of aquaculture effluents. We studied the potential use of two fouling species (Amphibalanus amphitrite and Saccostrea cucullata) in remediation of shrimp (Litopenaeus vannamei) farm wastewaters. Their abilities, individually and in combination, in reducing nitrogen, phosphorus, and phytoplankton (chlorophyll a) from effluents at three densities and three retention times (1, 3, 6 h) were investigated. The results showed that all treatments, specifically oysters, could effectively reduce nutrients and plankton concentrations. Oysters reduced total nitrogen, total phosphorus and chlorophyll a to 60.7%, 55.6%, and 7.6% of the initial contents at the high density (i.e. 0.80 oyster L−1) after 6 h. Barnacles and the combined use of both species, however, showed remarkably lower efficiencies. Our results demonstrated that oysters could potentially be used to improve water quality of shrimp farm effluents especially in the areas where oysters can be easily collected or cultured. Highlights • S. cucullata showed high efficiency in nutrients and chlorophyll a removal. • The highest efficiency in bioremediation was reached after 6 h treatment by oysters. • Best results were achieved using 0.80 oysters per liter. • Bioremediation ability: oyster > combined use of both species > barnacle. [ABSTRACT FROM AUTHOR]

Abstract Hull fouling has been a driving force behind the development of most modern marine antifouling coatings that mainly contain copper based biocides to inhibit growth of fouling organisms. Despite these efforts, several non-indigenous species continue to be transferred via hull-fouling worldwide. In this study we designed a disturbance gradient with three commercial antifouling paints applied to PVC settling plates with different concentrations of copper oxide and allowed colonization of fouling communities in four marinas located at the Madeira Archipelago (NE Atlantic). Overall, the antifouling treatments were effective in decreasing the diversity of fouling communities and spatial variability across marinas was observed. Increasing exposure to metal pollutants decreases both species cover and total diversity, independently of their native or NIS condition. However, evidences found suggest that long-term effects of copper based antifouling coatings can be modulated by metal-resistant species allowing a secondary substrate for the epibiosis of other species to establish. Highlights • Copper pollution significantly affected diversity of fouling communities and spatial variability was observed. • Increasing exposure to copper decreases species cover and total diversity, independently of their native or NIS statuses. • The settlement of native species in copper treated plates was facilitated by the occurrence of Watersipora subtorquata. • Non-toxic paint seems to favor NIS while absence of paint seems to favor the settlement of native species. [ABSTRACT FROM AUTHOR]

Abstract Numerical modelling is a key tool in understanding and determining the sources, trajectories and fates of micro-plastic debris (MPD). In this study, we introduce TrackMPD, a new modelling framework for the 3D transport of marine debris. TrackMPD fills the gaps in previous models by: (1) using a three-dimensional approach; (2) providing compatibility with a variety of ocean models; and (3) including a wide range of physical processes (advection, dispersion, windage, sinking, settling, beaching and re-floating) and MPD behaviours that depend on particle dynamical properties, and the fouling and degradation states. We implement a sensitivity analysis based on 44 scenarios to assess the relative importance of the different processes and behaviours on the MPD trajectories and fates. Results show that the MPD dynamical properties that impact their sinking, in particular plastic density and biofilm thickness and density, have the biggest effect on the MPD transport, followed by turbulent dispersion and washing-off. Graphical abstract Unlabelled Image Highlights • Novel three-dimensional approach for modelling marine plastic debris transport • Innovative modelling of physical processes and behaviour of microplastics • High influence of vertical current shear on the dispersion of microplastics • High impact of density and biofouling on sinking, and thus on trajectories and fates • Particle size impacts the trajectories of spherical particles, but not of cylindrical. [ABSTRACT FROM AUTHOR]

Abstract Shipping is understood to be a major vector for the introduction and spread of marine non-indigenous species (NIS). However, recreational boating is still unregulated and its influence as vector has not yet been assessed for the Mediterranean Sea, which is the second most popular recreational boating destination worldwide. This is the first large-scale study to examine this by a combined biological (analyzing hull and marina fouling) and social approach (boaters surveys on maintenance habits, travel patterns and awareness), focused on peracarid crustaceans. A surprisingly high number of NIS were found on vessels cruising Mediterranean waters, and species compositions suggest an exchange between marina and vessel assemblages. This means recreational boating presents a risk for NIS spread which should warrant regulation. Results also implied that regionally coordinated management should be supported by effective local-scale-based management in the Mediterranean, which could improve upon with targeted environmental education to solve lack of awareness. Highlights • This study examines boating as a vector of non-indigenous species (NIS) introductions. • Specifically, peracarid crustaceans are studied in marinas and boats in the Mediterranean. • Results show numerous NIS in marinas and vessels and suggest exchanges between them. • Vessel maintenance and travel patterns influence the likelihood of NIS occurrence. • There is a general lack of awareness of marine bioinvasions among recreational boaters. [ABSTRACT FROM AUTHOR]

Abstract The prevention of biofouling in the inner walls of closed photobioreactors (PBRs) becomes a critical step in improving the performance of photosynthetic microalgae bioprocesses. Selection of antifouling materials implies approaches at laboratory scale. This work reports the use of a flow cell of the modified Robbins device (MRD) type coupled to a PBR, operated in both batch and continuous modes with the model marine microalgae Nannochloropsis gaditana to study the biofouling formation on diverse materials. The fluid-dynamics within the MRD was studied via CFD-aided simulations. At separation distances lower than the cells' diffusion layer thickness, a diffusion-controlled transport of the cells to the material surface was postulated. Results suggested that the flow density of cells in the MRD (J z), governed by cell concentration gradients, is a significant factor in the adhesion intensity (B) when the PBR is operated in batch mode; not in the continuous mode where the differences observed in B between materials were mainly attributed to the type of material. Polyvinylchloride (PVC) was clearly the best anti-biofouling material compared to polycarbonate, polystyrene, borosilicate glass and stainless steel. The B maximum occurred at the end of the stationary phase in batch culture mode. Continuous culture operation seemed to be preferable since once steady state is achieved, the B value remained low and constant, indicating equilibrium between the number of adhered cells per surface unit and the cell concentration in the culture broth – this was because the adhered cells did not grow on the surface due to phosphate limitation. The PBR-coupled MRD has demonstrated to be well-suited for the screening of antifouling materials under fluid-dynamic conditions relevant in PBRs. Highlights • Microalgal biofouling was monitored with a flow cell attached in closed loop to a PBR • PBR biofouling was interpreted using CFD and modelling adhesion dynamics in a flow cell • Polyvinyl chloride and stainless steel presented less biofouling than other materials • Biofouling may be controlled by limiting the flow of nutrients to the PBR surface [ABSTRACT FROM AUTHOR]

Highlights • Current reviews on membrane fouling were reviewed. • On foulant aspect, the origin of novel foulants and biofoulants are widely studied. • Novel characterization tools and low-fouling membranes are proposed. • Extended blocking models and interfacial interaction models are developed. Abstract Membrane fouling is the single most influential factor that limits the membrane process performance in long-term operation. This mini-review reviewed the currently available review papers on membrane fouling studies and summarized the research trends from the conclusions highlighted by these reviews. On foulant aspect, the origin of novel foulants and the biofoulants are widely studied. On characterization and control strategy aspect, novel characterization tools and low-fouling membranes are to be proposed and tested, and the conventional and novel control strategies are under development. On mechanism part, the use of extended blocking models and the extended interfacial interaction models on interpreting fouling behavior is a research focus. Graphical abstract Image, graphical abstract [ABSTRACT FROM AUTHOR]

Highlights • A mixture feed showed a more representative evaluation of membrane fouling potential. • Membrane surface properties dominated the fouling effect at the initial stages of filtrations. • A feed with a single foulant resulted in an underestimation of the filtration resistance. • A Feed with a single foulant resulted in an overestimation of the irreversible fouling. • Interactions among foulants should be considered in evaluating membrane fouling. Abstract The biofouling mechanism of organic mixtures on porous polyvinylidene fluoride membranes was tested to determine how to examine the fouling potential of a membrane for water treatments with more representative feed compositions including protein, polysaccharides, and natural organic matters. The three-dimensional structure and compositions of the fouling layers were examined using confocal laser scanning microscopy and the filtration resistances of the fouled membranes were estimated. The filtration resistance analyses demonstrated that feeds with a single-component foulant will cause serious clogging in the pores and form a looser fouling layer structure on the membrane; however, a mixed composition resulted in less clogging in the pore and a denser layer structure on the membrane because of over-deposition and interactions among the foulants. The fouling potential of a membrane examined with a single-component will result in an under-estimation of the filtration resistance of the fouling layer and an over-estimation of irreversible fouling. Graphical abstract Image, graphical abstract Wastewaters composed of proteins, polysaccharides, and natural organic matters, as well as their binary and tertiary mixtures were adopted for cross-flow filtration experiments through the polyvinylidene fluoride (PVDF) membranes. The effects of membrane characteristics on membrane fouling, filtration resistances of the fouled membranes, and operating conditions were estimated in this study. [ABSTRACT FROM AUTHOR]

The Gulf of Oman is becoming increasingly polluted with plastics, hence bioplastics have been considered 'a substitute', although their biodegradability in marine environments has not been well investigated. Most research has been performed on cellulose-based bioplastics, whereas starch-based bioplastics have proven to be a suitable, but less researched, alternative. This study is the first of its kind designed to investigate the degradability of two different types of starch-based bioplastic bags, available in the market and labeled as "biodegradable", in the pelagic and benthic zones of one of the warmest marine environment in the world. Fourier-Transform Infrared Spectroscopy (FTIR) showed a clear reduction in the presence of OH, C H, and C O in the bioplastic bags after 5 weeks of immersion. Thermo-Gravimetric Analysis (TGA) indicated degradation of glycerol, starch, and polyethylene. The biofouling bacterial communities on bioplastic surfaces showed distinct grouping based on the immersion zone. Candidaatus saccharibacteria , Verrucomicrobiae , Acidimicrobiia and Planctomycetia sequences were only detectable on bioplastics in the pelagic zone, whereas Actinomyces , Pseudomonas , Sphingobium and Acinetobacter related sequences were only found on bioplastics in the benthic layer. We conclude that starch-based bioplastics are more readily degradable in the Gulf of Oman than conventional plastics, hence could serve as a better environmentally friendly alternative. [Display omitted] • Starch-based bioplastics were readily degradable in the Gulf of Oman. • TGA analysis indicated degradation of glycerol, starch and PE. • Biofouling communities were habitat- but not plastic-specific. • Candidatus saccharibacteria were enriched bioplastics in the planktonic zone. • Starch-based bioplastics could serve as a good alternative to conventional plastics. [ABSTRACT FROM AUTHOR]

A coral community was examined on a semi-submersible platform that was moored at the leeward side of Curaçao, in the southern Caribbean, from August 2016 until August 2017. This community included several non-native or cryptogenic species. Among them were two scleractinian corals (Tubastraea coccinea and T. tagusensis) and two octocorals (Chromonephthea sp. and an unidentified Nephtheidae sp.). This is the first reported presence of T. tagusensis in the southern Caribbean, and the genus Chromonephthea in the Caribbean region. An ascidian, Perophora cf. regina , is also reported from the southern Caribbean for the first time, as well as a coral-associated vermetid gastropod, Petaloconchus sp., first recorded in the Caribbean in 2014. Lack of biofouling management could potentially harm indigenous marine fauna through the introduction of non-native species. Therefore monitoring communities associated with semi-submersible platforms is essential to track the presence and dispersal of non-native, potentially invasive species. [Display omitted] • Curaçao has an extensive history of visits by semi-submersible platforms. • A semi-submersible platform at Curaçao hosted a dense, non-native coral community. • The biofouling community represents new species records for the southern Caribbean. • Semi-submersible platforms need regular monitoring for detecting non-native fauna. [ABSTRACT FROM AUTHOR]

Environmental spills of in-water hull cleaning wastewater (HCW) containing heavy metals and biocides is inevitable, and the effects of HCW on microalgae are unknown. To investigate this, we conducted microcosm experiments by adding HCW to natural seawater. HCW samples were obtained from two different cleaning methods (soft: sponge, hard: brush), and 5 % or 10 % were added to natural seawater as treatments. Dissolved Cu concentrations were 5 to 10 times higher in the treatments than those in the control. There were significant differences in growth of unattached microalgae depending on HCW dose (chlorophyll a : 34.1 ± 0.8 μg L−1 in control vs. 12.6 ± 4.3 μg L−1 in treatments). Conversely, the biomass of attached microalgae increased with HCW dose, which was associated with most of the nutrient reduction later in the experiment, rather than unattached microalgae. Our findings suggest that HCW can significantly impact microalgal community, especially depending on spill volume. • Ship's hull in-water cleaning wastewater (HCW) affected significantly on the microalgal communities. • Dissolved Cu from HCW had a negative effect on the growth of unattached microalgae. • Abundance of attached microalgae increased as HCW dose increased. • Microalgal community structure may change as a result of HCW effluent. • Regulating HCW effluent volume may be more important than cleaning intensity during in-water cleaning process. [ABSTRACT FROM AUTHOR]

A coral community was examined on a semi-submersible platform that was moored at the leeward side of Curaçao, in the southern Caribbean, from August 2016 until August 2017. This community included several non-native or cryptogenic species. Among them were two scleractinian corals (Tubastraea coccinea and T. tagusensis) and two octocorals (Chromonephthea sp. and an unidentified Nephtheidae sp.). This is the first reported presence of T. tagusensis in the southern Caribbean, and the genus Chromonephthea in the Caribbean region. An ascidian, Perophora cf. regina , is also reported from the southern Caribbean for the first time, as well as a coral-associated vermetid gastropod, Petaloconchus sp., first recorded in the Caribbean in 2014. Lack of biofouling management could potentially harm indigenous marine fauna through the introduction of non-native species. Therefore monitoring communities associated with semi-submersible platforms is essential to track the presence and dispersal of non-native, potentially invasive species. [Display omitted] • Curaçao has an extensive history of visits by semi-submersible platforms. • A semi-submersible platform at Curaçao hosted a dense, non-native coral community. • The biofouling community represents new species records for the southern Caribbean. • Semi-submersible platforms need regular monitoring for detecting non-native fauna. [ABSTRACT FROM AUTHOR]

Environmental spills of in-water hull cleaning wastewater (HCW) containing heavy metals and biocides is inevitable, and the effects of HCW on microalgae are unknown. To investigate this, we conducted microcosm experiments by adding HCW to natural seawater. HCW samples were obtained from two different cleaning methods (soft: sponge, hard: brush), and 5 % or 10 % were added to natural seawater as treatments. Dissolved Cu concentrations were 5 to 10 times higher in the treatments than those in the control. There were significant differences in growth of unattached microalgae depending on HCW dose (chlorophyll a : 34.1 ± 0.8 μg L−1 in control vs. 12.6 ± 4.3 μg L−1 in treatments). Conversely, the biomass of attached microalgae increased with HCW dose, which was associated with most of the nutrient reduction later in the experiment, rather than unattached microalgae. Our findings suggest that HCW can significantly impact microalgal community, especially depending on spill volume. • Ship's hull in-water cleaning wastewater (HCW) affected significantly on the microalgal communities. • Dissolved Cu from HCW had a negative effect on the growth of unattached microalgae. • Abundance of attached microalgae increased as HCW dose increased. • Microalgal community structure may change as a result of HCW effluent. • Regulating HCW effluent volume may be more important than cleaning intensity during in-water cleaning process. [ABSTRACT FROM AUTHOR]

Highlights • Offshore wind farms (OWFs) modify benthic habitats, leading to biodiversity change. • Links in biodiversity change and ecosystem services, for OWFs, were conceptualised. • The conceptual model shows OWFs can alter delivery of ecosystem services. Abstract The growing awareness of climate change and the recognised need to secure energy production has been a driving force behind the expansion of the offshore wind industry across the world. Benefits from offshore wind farms (OWFs) may extend further than low CO 2 energy production. Wind turbine substructures introduce hard surfaces that are rapidly colonised by epibenthic marine organisms, altering biomass and biodiversity within the local ecosystem. Biodiversity plays a critical role in supporting ecosystem processes and functions that maintain ecosystem services. As offshore wind development continues to grow and modify marine habitats, changes in biodiversity could affect the provision of ecosystem services. In this context, this review sets out to capture the current understanding of epibenthic biodiversity change following the installation of OWFs and attempt to link these changes in biodiversity with marine ecosystem services through the associated processes and functions. [ABSTRACT FROM AUTHOR]

Abstract Oil refineries are known for the large volume of water used in their processes, as well as the amount of wastewater generated at the end of the production chain. Due to strict environmental regulations, the recycling of water has now become a viable alternative for refineries. Among the many methods available to treat wastewater for reuse, the use of membranes in reverse osmosis systems stands out due to several economic and environmental benefits. However, these systems are vulnerable to contamination and deposition of microorganisms, mainly because of the feedwater quality. In this study, the microbial diversity of feedwater and reverse osmosis membranes was investigated using a combination of culture-dependent and culture-independent methods in order to characterize the microorganisms colonizing and deteriorating the membranes. In total, 37 bacterial isolates, 17 filamentous fungi and approximately 400 clones were obtained and analyzed. Among the bacterial genera identified, the most represented were Sphingobium , Acidovorax , Microbacterium , Rhizobium and Shinella. The results revealed genera that acted as candidate key players in initial biofilm formation in membrane systems, and provided important information concerning the microbial ecology of oligotrophic aquatic systems. [ABSTRACT FROM AUTHOR]

Marine invasive species are widely recognized as one of the worst threats to marine ecosystems integrity, unbalancing native communities, which may lead to paramount ecological and economic impacts. Within invasive seaweeds, Sargassum muticum and Asparagopsis armata are recognized as successful invaders in Europe and America. Despite several attempts to control the spread of marine invaders, until now, all have proven to be elusive, and therefore, alternative strategies should be embraced. Worldwide, seaweeds have been increasingly explored due to their ability to produce bioactive compounds. However, one of the main problems associated with the production/extraction of these bioactive compounds for new products development, is the source availability and the potential negative environmental consequences of this exploitation. Within this framework, the use of invasive species to obtain natural bioactive compounds presents us with a two-folded opportunity - high availability of the biological material for the extraction of unique bioactive compounds for new products development, and through specimen collection, mitigating negative effects caused by alien species, contributing for ecosystem integrity and sustainability. Over the last decades, the brown seaweed S. muticum and the red A. armata have been studied all over the world for their capacity to produce bioactive compounds, with main results pointing towards their high potential as producers of antioxidant, antifouling, antimicrobial, and antitumor compounds. The present review summarizes the biotechnological potential of S. muticum and A. armata as producers of bioactive compounds, while addressing the potential use of global threats as important blue growth pawns. [ABSTRACT FROM AUTHOR]