Marine Fouling Organisms Research Articles

海洋付着生物を模倣した機能性材料

海洋付着生物を模倣した機能性材料

Marine Environmental Risk Assessment Method for Active Substances Used in Antifouling Systems on Ships in China

A Chinese risk assessment procedure was developed to address active substances used in biologically active (biocidal) antifouling paints. The priority was to promote the use of environmentally friendly, technically and economically viable alternatives to DDT/TBT (dichlorodiphenyltrichloroethane/tributyltin) in the control of marine fouling organisms. The procedure was based upon European Union Biocide Product Directive (EU-BPD) and International Standard Organization (ISO) method for the Environmental risk assessment of antifouling systems. In order to focus on Chinese national conditions, international templates were adapted to address regional differences. In the Chinese method, persistence, bioaccumulation and toxicity information is assessed on a step by step basis, allowing an antifouling substance to be defined as either Risk of high concern or Relatively low risk at the end of the decision making process. 4,5-Dichloro-2-n-Octyl-3-Isothiazolinone (DCOIT, Sea-nine), triphenylborane pyridine (TPBP), 8-methyl-N-vanillyl-6-nonenamide (Capsaicin) and Zinc ethylene (bis) dithiocarbamate (Zineb), popularly used in China as active substance of antifouling paints, were reviewed according to the developed procedure. The preliminary results indicate that Sea-nine use in antifouling products can be considered low risk, whereas TPBP, Capsaicin and Zineb failed the screening procedure on the basis of bioaccumulation potential, persistence and an unacceptable risk ratio, respectively. Data availability was determined to be a critical factor in the assessments due to the application of Safety Factors for data-poor substances.

The interaction of marine fouling organisms with topography of varied scale and geometry: a review

Many studies have examined the effects of surface topography on the settlement behaviour of marine organisms and this article reviews these investigations with more emphasis on the effects of topography scale. It has been observed that macro topographies (1-100 mm) are generally favoured by marine fouling taxa and are unsuitable for antifouling applications. This is because macro topographies are usually large enough to fit fouling organisms and provide refuge from dangers in the marine environment. Micro topographies had only limited success at reducing fouling from a wide range of marine taxa. The antifouling performance of micro topographies (1 to ≤ 1000 μm) is dependent on the properties of topography features in terms of symmetry, isotropy, width, length, height/depth, separation distance and average roughness. In terms of the antifouling performance of micro topography, topography geometry may only be of secondary importance in comparison to the size of features itself. It is also noted that hydrodynamic stresses also contribute to the settlement trends of foulers on textured surfaces. Future studies on antifouling topographies should be directed to hierarchical topographies because the mixed topography scales might potentially reduce fouling by both micro and macro organisms. Patterned nano-topographies (1- ≤ 1000 nm) should also be explored because the antifouling mechanisms of these topographies are not yet clear.

Slippery Liquid-Infused Porous Surfaces Showing Marine Antibiofouling Properties

Marine biofouling is a longstanding problem because of the constant challenges placed by various fouling species and increasingly restricted environmental regulations for antifouling coatings. Novel nonbiocidal strategies to control biofouling will necessitate a multifunctional approach to coating design. Here we show that slippery liquid-infused porous surfaces (SLIPSs) provide another possible strategy to obtaining promising antifouling coatings. Microporous butyl methacrylate-ethylene dimethacrylate (BMA-EDMA) surfaces are prepared via UV-initiated free-radical polymerization. Subsequent infusion of fluorocarbon lubricants (Krytox103, Krytox100, and Fluorinert FC-70) into the porous microtexture results in liquid-repellent slippery surfaces. To study the interaction with marine fouling organisms, settlement of zoospores of the alga Ulva linza and cypris larvae of the barnacle Balanus amphitrite is tested in laboratory assays. BMA-EDMA surfaces infused with Krytox103 and Krytox100 exhibit remarkable inhibition of settlement (attachment) of both spores and cyprids to a level comparable to that of a poly(ethylene glycol) (PEG)-terminated self-assembled monolayer. In addition, the adhesion strength of sporelings (young plants) of U. linza is reduced for BMA-EDMA surfaces infused with Krytox103 and Krytox100 compared to pristine (noninfused) BMA-EDMA and BMA-EDMA infused with Fluorinert FC-70. Immersion tests suggest a correlation between the stability of slippery coatings in artificial seawater and fouling resistance efficacy. The results indicate great potential for the application of this concept in fouling-resistant marine coatings.

Using textured PDMS to prevent settlement and enhance release of marine fouling organisms

The antifouling efficacy of a series of 18 textured (0.2–1000 μm) and non-textured (0 μm) polydimethylsiloxane surfaces with the profiles of round- and square-wave linear grating was tested by recording the settlement of fouling organisms in the laboratory and in the field by monitoring the recruitment of a multi-species fouling community. In laboratory assays, the diatoms Nitzschia closterium and Amphora sp. were deterred by all surface topographies regardless of texture type. Settlement of propagules of Ulva sp. was lower on texture sizes less than the propagule size, and settlement of larvae of Saccostrea glomerata and Bugula neritina was lower on texture sizes closest to, but less than, the sizes of larvae. After a six month field trial, all textured surfaces lost their deterrent effect; however, the foul-release capabilities of textures were still present. High initial attachment was correlated with most fouling remaining after removal trials, indicating that fouling organisms recruited in higher numbers to surfaces upon which they attached most strongly.

ChemInform Abstract: Molecular Surface Chemistry in Marine Bioadhesion

AbstractReview: 261 refs.

Adhesion of Marine Fouling Organisms on Hydrophilic and Amphiphilic Polysaccharides

Polysaccharides are a promising material for nonfouling surfaces because their chemical composition makes them highly hydrophilic and able to form water-storing hydrogels. Here we investigated the nonfouling properties of hyaluronic acid (HA) and chondroitin sulfate (CS) against marine fouling organisms. Additionally, the free carboxyl groups of HA and CS were postmodified with the hydrophobic trifluoroethylamine (TFEA) to block free carboxyl groups and render the surfaces amphiphilic. All coatings were tested with respect to their protein resistance and against settlement and adhesion of different marine fouling species. Both the settlement and adhesion strength of a marine bacterium (Cobetia marina), zoospores of the seaweed Ulva linza, and cells of a diatom (Navicula incerta) were reduced compared to glass control surfaces. In most cases, TFEA capping increased or maintained the performance of the HA coatings, whereas for the very well performing CS coatings the antifouling performance was reduced after capping.

Effect of seaweed epibiotic bacterium Streptomyces violaceoruber SCH-09 on marine fouling organisms

Seaweed-associated bacteria play a role in helping to protect host organisms from biofouling by producing anti-fouling compounds. In a first step to develop such anti-fouling compounds, we isolated epibiotic bacteria from seaweed and subsequently screen culture extracts for anti-fouling activities. The active epibiotic bacterium studied was isolated from Undaria pinnatifida and identified as Streptomyces violaceoruber based on 16S rDNA sequence analysis. Two active compounds were isolated from the culture extracts by silica gel chromatography and high-performance liquid chromatography, and their structures were analyzed by nuclear magnetic resonance and high-resolution electron ionization mass spectrometry. The compounds were identified as furanone derivatives: 3-octa-1′,3′-dienyl-4-methylfuran-2(5H)-one and 3-octa-1′-enyl-4-methylfuran-2(5H)-one, respectively. These compounds showed anti-fouling activities against the following fouling organisms: zoospores of Ulva pertusa, the diatom Navicula annexa, and the mussel Mytilus edulis, with an EC50 (minimum concentration for 50 % spore inhibition) range of 0.02–0.1 μg/ml. In the acute toxicity tests on juvenile rockfish Shebastes shlegelli, brine shrimp Artemia salina, and microalga Tetraselmis suecica, the two compounds showed LC50 (concentration lethal to 50 % of the spores) ranges of 13.9–118.9 and 14.8–81.9 μg/ml, respectively.

Highly toxic ribbon worm Cephalothrix simula containing tetrodotoxin in Hiroshima Bay, Hiroshima Prefecture, Japan.

In 1998, during a toxicological surveillance of various marine fouling organisms in Hiroshima Bay, Japan, specimens of the ribbon worm, Cephalothrix simula (Nemertea: Palaeonemertea) were found. These ribbon worms contained toxins with extremely strong paralytic activity. The maximum toxicity in terms of tetrodotoxin (TTX) was 25,590 mouse units (MU) per gram for the whole worm throughout the monitoring period. The main toxic component was isolated and recrystallized from an acidified methanolic solution. The crystalline with a specific toxicity of 3520 MU/mg was obtained and identified as TTX by high performance liquid chromatography (HPLC)-fluorescent detection (FLD) (HPLC-FLD), electrospray ionization-mass spectrometry (ESI-MS), infrared (IR), nuclear magnetic resonance (NMR) and gas chromatography–mass spectrometry (GC-MS). The highest toxicity of C. simula exceeded the human lethal dose per a single worm. A toxicological surveillance of C. simula from 1998 to 2005 indicated approximately 80% of the individuals were ranked as “strongly toxic” (≥1000 MU/g). Forty-eight percent of the specimens possessed toxicity scores of more than 2000 MU/g. Seasonal variations were observed in the lethal potency of C. simula. Specimens collected on January 13, 2000 to December 26, 2000 showed mean toxicities of 665–5300 MU/g (n = 10). These data prompted a toxicological surveillance of ribbon worms from other localities with different habitats in Japan, including Akkeshi Bay (Hokkaido) under stones on rocky intertidal beaches, as well as Otsuchi (Iwate) among calcareous tubes of serpulid polychaetes on rocky shores. Within twelve species of ribbon worms examined, only C. simula possessed extremely high toxicity. Therefore, C. simula appears to show generally high toxicity irrespective of their locality and habitat.

The effect of vibration frequency and amplitude on biofouling deterrence

The use of vibration is proposed as a means of controlling the settlement of marine fouling organisms. In this study, panels with embedded lead zirconate titanate, known as PZT, were placed in the field over 3 months. The panels were vibrated at different velocity levels at frequencies between 70 and 445 Hz. It was found that barnacles (Amphibalanus variegatus Darwin and Elminius sp.) were the only fouling organisms affected by the applied vibration, and these organisms settled in significantly lower numbers when the plates were excited at specific frequencies and amplitudes. Panels vibrating at relatively higher frequencies, greater than 260 Hz, exhibited reduced barnacle settlement, whilst lower frequencies in the 70–100 Hz range had little or no effect. The settlement of other fouling organisms such as tubeworms, bryozoans, ascidians and algae did not appear to be affected by the applied excitation. The experimental results showed that increasing the velocity amplitude of vibration was a contributing factor in inhibiting barnacle settlement.

The Synthesis and Bioactivities of 2-Hydroxyethyl Benzo[d] Isothiazole-3(2H)-One Marine Antifouling Paints

Twenty-one novel compounds were synthesized from the benzo[d]isothiazole-3(2H)-one and aromatic acid, the structures were identified by means of 1H NMR, IR, EA. The intro antibacterial experiment was carried out to evaluate the activities against antibacterial and the marine hanging plate experiment was also carried out to evaluate the activities against marine fouling organism. The results showed that all the compounds were active against the six bacterials, with an inhibiting rate of 90% at the concentration of 32 µg/ml against Gram-positive bacterials, and the antifouling paints couldn’t be attached by marine fouling organisms in the marine environment for more than 3 months.

Study on biomimetic preparation of shell surface microstructure for ship antifouling

The attachment of marine fouling organisms is harmful to any marine structure such as ship hulls, fishing nets, jetties and platforms. The surface microstructure of materials has a great influence on its antifouling performance. The surfaces of some types of shells are very clean without fouling even though they are in seawater for long time, which can be used as biomimetic objects for antifouling. In order to study ship green antifouling technology based on biomimetic shell microstructure, three common marine shells Dosinia japonica, Gafrarium pectinatum and Mimachlamys nobilis were selected to study the relationship between the shell surface microstructure and the antifouling performance. Taking the outside surface of the three shells as the bio-replication templates, polydimethylsiloxane (PDMS) as female mold, E44 epoxy resin and polyurethane (PU) as male mold materials, the replicas were prepared by means of the bio-replicated forming method. The surfaces were measured with the LI-3 contact surface profilometer and the form errors of measuring data were then separated by two-dimensional biorthogonal wavelet transform. Seven three-dimensional surface parameters, Sa, Sq, Ssk, Sku, Sy, Sz and Stdi were calculated to compare each replica with the original surface. The results showed that E44 epoxy resin and PU accurately reproduced the shell surface microstructure with the relative errors mostly lower than 10%. The replica accuracy of the epoxy resin was a little bit better than that of PU for fine tiny microstructure. Fouling tests with E44 epoxy resin replicas were conducted in laboratory for 4 weeks. The content of chlorophyll-a of Nitzschia closteriums was then used to characterize the antifouling ability of the replicas. The chlorophyll-a content results and the contact angle analysis showed that the E44 replica of D. japonica had the best antifouling ability while the E44 replica of M. nobilis had the worst antifouling ability among three kinds of E44 replicas.

Study on the marine growth effect on the dynamic response of offshore wind turbines

Jacket foundation is regarded as a suitable solution for wind turbines in the intermediate water depths ranging from 30 to 80 m. Numerous types of marine fouling organisms may be found on the submerged members of jacket. Marine growth is found to influence loading of offshore structures by increasing tube diameters, drag coefficient, mass and hydrodynamic added mass and structural weight. In this paper, the types and distribution of marine growth are mentioned. We aimed to investigate the effects of marine growth with different thicknesses, densities and hydrodynamic coefficients values on characteristics of an offshore wind turbine with jacket foundation. The eigen analysis shows that the marine growth has a little effect on the first order natural frequencies while it has higher effect on second and third order natural frequencies of the support structure. Thickness and density have a strong effect on hydrodynamic loads. To obtain the properties of marine growth and hydrodynamic coefficients in the design of offshore wind turbines, full-scale measurements are needed.

美丽海绵提取物防污损作用

Around the world,marine fouling can have serious impacts on human activities and other organisms.To survive in the highly competitive arena of the marine environment,many organisms have developed unique protection mechanisms against fouling,including tolerance,avoidance,low surface energy and the secretion of natural compounds.Some species of sponge and coral are rarely epiphytized because of the production of secondary metabolites against fouling.Unlike common man-made antifouling compounds,these natural chemicals are environmentally friendly in marine ecological systems. The majority of marine fouling organisms are algae,coelenterates,polychaetes,bivalves,bryozoans and barnacles.Of them,the acorn barnacle Balanus reticulatus is one of the most important dominant species in the fouling communities of tropical and subtropical waters,particularly in the East and South China Sea.Thus is can be considered as an appropriate test representative for antifouling bioassays. Barnacle nauplii were obtained by dissecting freshly collected adult barnacles from the aquaculture facilities at Daya Bay,Shenzhen,China.Barnacle larvae were reared in darkness,at 30℃ and on a diet of the green algae Platymonas subcordiformis.Seawater was changed and more algae added as necessary.Cyprid larvae developed after around 5 days and were collected and stored at 4℃ for subsequent use. Sponges of the genus Callyspongia are widely distributed in the southern waters of China(e.g.coastal water of Fujian,Guangdong,Guangxi and Hainan Provinces).They are well known as sources of biologically active natural products,including polyacetylenes,peptides,alkaloids,fatty acids,polyketides,and sterols.Some of these compounds possess antimicrobial,anti-tumor,cytotoxicic,and HIV reverse transcriptase inhibition properties. Freshly collected samples of Callyspongia were minced and extracts taken by washing with dilute ethanol three times.The aqueous ethanol extracts were concentrated under vacuum.The combined extracts were partitioned into ethyl acetate and water.The ethyl acetate soluble portion was separated using column chromatography.A silica gel column was eluted with petroleum ether / ethyl acetate and then ethyl acetate / acetone.Similar isolates were identified using thin layer chromatography(TLC).The structures of all isolates were determined using one dimensional and two dimensional nuclear resonance microscopy(NMR),mass spectroscopy(MS) analyses,and by comparison of the spectroscopic data with those reported in the literature.A total of eight compounds were isolated and purified: Cyclo-(S-Pro-Gly),Cyclo-Pro-Ala,1-(2′-deoxy-β-D-erythro-pentofuranosyl)-1-H-1,2,4-triazole,uracil,4-(1-phenylethyl) phenol,6-NH2-purine,1-H-1,2,4,triazole and cholest-5-ene-3β,7α-diol. For antifouling tests,each compound was dissolved in 1ml methanol(or chloroform) and transferred into Petri dishes.Petri dishes were dried on a shaker prior to the addition of filtered seawater and larvae.Control dishes,using 1 ml of solvent(pre dried as above) and filtered seawater only were also prepared.The mean values of larval survival rate were compared among samples using least significant difference tests. Six compounds had no influence on the behavior and survival rate of larvae(P0.05): 1-(2′-deoxy-β-D-erythro-pentofuranosyl)-1-H-1,2,4-triazole,Cyclo-(S-Pro-Gly),Cyclo-Pro-Ala,uracil,1-H-1,2,4,triazole and cholest-5-ene-3β,7α-diol.The other two compounds 6-NH2-purine(7.1 μg/cm2) and 4-(1-phenylethyl) phenol(5.9 μg/cm2) had significant toxic effects on the cyprid larvae of the acorn barnacle Balanus reticulatus(P0.05).The synergistic effect of these compounds may play an important role in the antifouling activities of the sponge.

Resistance of Galactoside-Terminated Alkanethiol Self-Assembled Monolayers to Marine Fouling Organisms

Self-assembled monolayers (SAMs) of galactoside-terminated alkanethiols have protein-resistance properties which can be tuned via the degree of methylation [Langmuir 2005, 21, 2971-2980]. Specifically, a partially methylated compound was more resistant to nonspecific protein adsorption than the hydroxylated or fully methylated counterparts. We investigate whether this also holds true for resistance to the attachment and adhesion of a range of marine species, in order to clarify to what extent resistance to protein adsorption correlates with the more complex adhesion of fouling organisms. The partially methylated galactoside-terminated SAM was further compared to a mixed monolayer of ω-substituted methyl- and hydroxyl-terminated alkanethiols with wetting properties and surface ratio of hydroxyl to methyl groups matching that of the galactoside. The settlement (initial attachment) and adhesion strength of four model marine fouling organisms were investigated, representing both micro- and macrofoulers; two bacteria (Cobetia marina and Marinobacter hydrocarbonoclasticus), barnacle cypris larvae (Balanus amphitrite), and algal zoospores (Ulva linza). The minimum in protein adsorption onto the partially methylated galactoside surface was partly reproduced in the marine fouling assays, providing some support for a relationship between protein resistance and adhesion of marine fouling organisms. The mixed alkanethiol SAM, which was matched in wettability to the partially methylated galactoside SAM, consistently showed higher settlement (initial attachment) of test organisms than the galactoside, implying that both wettability and surface chemistry are insufficient to explain differences in fouling resistance. We suggest that differences in the structure of interfacial water may explain the variation in adhesion to these SAMs.

Progress of marine biofouling and antifouling technologies

Adhesion of marine fouling organisms on artificial surfaces such as ship hulls causes many problems, including extra energy consumption, high maintenance costs, and increased corrosion. Therefore, marine antifouling is an important issue. In this review, physical and biochemical developments in the field of marine biofouling, which involves biofilm formation and macro-organism settlement, are discussed. The major antifouling technologies based on traditional chemical methods, biological methods, and physical methods are presented. The chemical methods include self-polishing types such as tributyltin (TBT) self-polishing copolymer coatings, which despite its good performance has been banned since 2008 because of its serious environmental impact. Therefore, other methods have been encouraged. These include coatings with copper compounds and biocide boosters to replace the TBT coatings. Biological extracts of secreted metabolites and enzymes are anticipated to act as antifoulants. Physical methods such as modification of surface topography, hydrophobic properties, and charge potential have also been considered to prevent biofouling. In this review, most of the current antifouling technologies are discussed. It is proposed that the physical antifouling technologies will be the ultimate antifouling solution, because of their broad-spectrum effectiveness and zero toxicity.

Antifouling potential of Subtilisin A immobilized onto maleic anhydride copolymer thin films

The proteinaceous nature of the adhesives used by most fouling organisms to attach to surfaces suggests that coatings incorporating proteolytic enzymes may provide a technology for the control of biofouling. In the present article, the antifouling (AF) and fouling release potential of model coatings incorporating the surface-immobilized protease, Subtilisin A, have been investigated. The enzyme was covalently attached to maleic anhydride copolymer thin films; the characteristics of the bioactive coatings obtained were adjusted through variation of the type of copolymer and the concentration of the enzyme solution used for immobilization. The bioactive coatings were tested for their effect on the settlement and adhesion strength of two major fouling species: the green alga Ulva linza and the diatom Navicula perminuta. The results show that the immobilized enzyme effectively reduced the settlement and adhesion strength of zoospores of Ulva and the adhesion strength of Navicula cells. The AF efficacy of the bioactive coatings increased with increasing enzyme surface concentration and activity, and was found to be superior to the equivalent amount of enzyme in solution. The results provide a rigorous analysis of one approach to the use of immobilized proteases to reduce the adhesion of marine fouling organisms and are of interest to those investigating enzyme-containing coating technologies for practical biofouling control.

Poly(ethylene glycol)-Containing Hydrogel Surfaces for Antifouling Applications in Marine and Freshwater Environments

This work describes the fabrication, characterization, and biological evaluation of a thin protein-resistant poly(ethylene glycol) (PEG)-based hydrogel coating for antifouling applications. The coating was fabricated by free-radical polymerization on silanized glass and silicon and on polystyrene-covered silicon and gold. The physicochemical properties of the coating were characterized by infrared spectroscopy, ellipsometry, and contact angle measurements. In particular, the chemical stability of the coating in artificial seawater was evaluated over a six-month period. These measurements indicated that the degradation process was slow under the test conditions chosen, with the coating thickness and composition changing only marginally over the period. The settlement behavior of a broad and diverse group of marine and freshwater fouling organisms was evaluated. The tested organisms were barnacle larvae (Balanus amphitrite), algal zoospores (Ulva linza), diatoms (Navicula perminuta), and three bacteria species (Cobetia marina, Marinobacter hydrocarbonoclasticus, and Pseudomonas fluorescens). The biological results showed that the hydrogel coating exhibited excellent antifouling properties with respect to settlement and removal.

Pyrethroids as Promising Marine Antifoulants: Laboratory and Field Studies

Due to the regulations and bans regarding the use of traditional toxic chemicals against marine fouling organisms and the practical impediments to the commercialization of natural product antifoulants, there is an urgent need for compounds that are antifouling-active, environmentally friendly, and have a potential for commercial application. In this study, a series of common, commercially available pyrethroid products, which are generally used as environmentally safe insecticides, was evaluated for antifouling activity in the laboratory using an anti-settlement test with cyprids of the barnacle Balanus albicostatus and also in a field experiment. Laboratory assay showed that all eleven pyrethroids (namely, rich d-trans-allethrin, Es-biothrin, rich d-prallethrin, S-prallethrin, tetramethrin, rich d-tetramethrin, phenothrin, cyphenothrin, permethrin, cypermethrin, and high active cypermethrin) were able to inhibit barnacle settlement (EC(50) range of 0.0316 to 87.00 microg/ml) without significant toxicity. Analysis of structure-activity relationships suggested that the cyano group at the alpha-carbon position had a significant influence on the expression of antifouling activity in pyrethroids. In the field, the antifouling activity of pyrethroids was further confirmed, with the most potent pyrethroids being cypermethrin and high active cypermethrin, which displayed efficiency comparable with that of tributyltin. In summary, our investigation indicated that these pyrethroids have a great and practical commercial potential as antifouling agents.

Anomalous settlement behavior of Ulva linza zoospores on cationic oligopeptide surfaces

Identification of settlement cues for marine fouling organisms opens up new strategies and methods for biofouling prevention, and enables the development of more effective antifouling materials. To this end, the settlement behaviour of zoospores of the green alga Ulva linza onto cationic oligopeptide self-assembled monolayers (SAMs) has been investigated. The spores interact strongly with lysine- and arginine-rich SAMs, and their settlement appears to be stimulated by these surfaces. Of particular interest is an arginine-rich oligopeptide, which is effective in attracting spores to the surface, but in a way which leaves a large fraction of the settled spores attached to the surface in an anomalous fashion. These ‘pseudo-settled’ spores are relatively easily detached from the surface and do not undergo the full range of cellular responses associated with normal commitment to settlement. This is a hitherto undocumented mode of settlement, and surface dilution of the arginine-rich peptide with a neutral triglycine peptide demonstrates that both normal and anomalous settlement is proportional to the surface density of the arginine-rich peptide. The settlement experiments are complemented with physical studies of the oligopeptide SAMs, before and after extended immersion in artificial seawater, using infrared spectroscopy, null ellipsometry and contact angle measurements.