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The depth culture influence (4, 8, and 16 m) and periods (upwelling and non-upwelling) on growth and survival of the pearl oyster Pinctada imbricata during 10 months in the southeastern Caribbean Sea (Cariaco Gulf) were evaluated. Monthly records were taken of survival, body growth, and fouling organisms of the pearl oyster, as well as weekly samples of the temperature, chlorophyll a, and seston of the water culture site. Monthly survival was above 92% at all depths. The variation in shell size and tissue mass of the oysters cultivated in the different depths showed a similar pattern, with slow growth during the non-upwelling period (June–October) and progressive growth during the upwelling period (November–April). The multivariate analysis showed that oyster growth was associated with the phytoplankton biomass at different depths, particularly during the upwelling period. Oysters at 4 m showed the greatest increases in all growth parameters, exceeding the minimum commercial size (50 mm) in 7 months. Hence, it is recommended that the culture of P. imbricata in the Gulf of Cariaco be started right before the upwelling season to take advantage of the high amount of food available during this period. It is also recommended that the suspended culture should not exceed 8 m for higher growth performance. [ABSTRACT FROM AUTHOR]

Eelgrass (Zostera marina) meadows and boat mooring fields co-occur in nearshore, relatively sheltered embayments. Traditional chain moorings create denuded scars in eelgrass meadows due to repeated and chronic scour of the seafloor by the chain, impacting meadow contiguity and quality. This study assessed the recovery of eelgrass into mooring scars following the conversion of traditional chain moorings to floating rode conservation mooring systems (CMS) in three Massachusetts harbors. The magnitude of eelgrass recovery following the conversion of 21 moorings to floating rode CMS was contingent on the location and positively correlated with the size of the scar associated with the mooring. While most scars started to revegetate following mooring conversion, few experienced complete recoveries and had a persistent denuded halo averaging 2 m in radius around the mooring anchors 5 years post-conversion. We observed CMS gear dragging on the bottom and impacting eelgrass when it was oversized for the depth of the site, and when it was not maintained or cleaned of fouling organisms. Overall, we show that floating rode CMS can be an important tool for eelgrass conservation; however, eelgrass recoveries following mooring conversion to floating rode CMS are variable and incomplete, and challenges pertaining to proper installation and long-term maintenance must be addressed to fully realize this potential. [ABSTRACT FROM AUTHOR]

The purpose of this study is to describe fishermen's and managers' current awareness of International Maritime Organization (IMO) biofouling guidelines to improve biofouling management on all fishing vessel types in the northern Persian Gulf. A total of 234 in-depth and semi-structured interviews were conducted face-to-face with fishermen and managers using a random sampling technique from February to November 2021. Analyses of data indicated that the majority of industrial fishermen (87%) and all of managers were aware of the IMO biofouling guidelines, but traditional fishermen had a low level of awareness (38%) and they had also many problems such as increased cost, lack of training courses, lack of sufficient facilities for implementation of IMO biofouling guidelines. For industrial fishermen, literacy was a most effective variable on awareness of IMO guidelines (p ˂ 0.05, r = 1.62). As regulations to prevent invasions and the accumulation of biofouling in fishing gear and fleets, biofouling should be managed and evaluated, and also training should be provided to fishermen to clean the biofouling of fishing gear and fleets in accordance with IMO guidelines, as well as more monitoring by managers, environmentalists, the government, and policymakers. [ABSTRACT FROM AUTHOR]

The metallic pyrithiones are used as antifouling paints for marine vehicles against fouling organisms. However, they are dissolved in marine water and have negative impacts on marine non-target organisms. This study evaluated the adverse effects of sodium pyrithione (NaPT) on Mytilus galloprovincialis using total hemocyte counts (THCs), oxidative stress and antioxidant parameters, and histopathological observations. Mussels were exposed to 0.1 and 1 μg/L NaPT for 96 h. The THC values of the NaPT-exposed mussels significantly decreased (p < 0.05). Lipid peroxidation and advanced oxidative protein products of digestive gland and gill tissues were decreased but only the digestive gland tissues of 0.1 μg/L NaPT values were significantly decreased compared to control groups (p < 0.05). Histological alterations were observed in the gill and the digestive gland tissues revealing malformations and hyperplasia of gill lamella; degenerations and loss of tubules of digestive gland after exposure to NaPT for 96 h. As a result, biocidal sodium pyrithione has adverse effects on the mussels even in short-term exposures and low concentrations. [ABSTRACT FROM AUTHOR]

Marine biofouling, undesirable growth of organisms on submerged surfaces, poses significant challenges in various industries and marine applications. The development of environmentally safe antifouling coatings employing nano-MnO2/cellulose nanofiber (CNF) composite with bisphenol A epoxy diacrylate/glycidyl methacrylate (BED/GMA) irradiated by electron beam (T1) has been achieved in the current work. The physico-chemical characteristics of the fabricated coatings have been studied using Fourier transforms infrared spectroscopy, scanning electron microscope, water contact angle, and X-ray diffraction. The efficacy of T1 formulation and pure BED/GMA polymer (T2) in inhibiting biofouling formation was investigated in seawater of Alexandria Eastern Harbour by examining biofilm development morphologically and biochemically. In addition, regular analyses of seawater physicochemical parameters were conducted monthly throughout study. Results provide valuable information on coating performance as well as the complex interactions between coatings, biofilms, and environmental factors. The T1 formulation exhibited strong anti-fouling and anticorrosion properties over 2 months. However, after four months of immersion, all coated steel surfaces, including T1, T2, and T0, were heavily covered with macro-fouling, including tubeworms, barnacles, and algae. Biochemical analysis of extracellular polymeric substances (EPS) showed statistically significant variations in carbohydrates content between the coated surfaces. The T1 formulation showed decreased protein and carbohydrate content in EPS fractions after 14 days of immersion indicating less biofouling. Moreover, elemental analysis showed that carbon, oxygen, and iron were the predominant elements in the biofilm. Other elements such as sodium, silicon, chloride, and calcium were in lower concentrations. T2 and T0 surfaces revealed higher calcium levels and the appearance of sulphur peaks if compared with T1 surface. Diatoms and bacteria were detected on T1, T2, and T0 surfaces. The observed warming of seawater and nutrient-rich conditions were found to promote the growth of fouling organisms, emphasizing the importance of considering environmental factors in biofouling management strategies. [ABSTRACT FROM AUTHOR]

This is a phylogeographical study of Juxtacribrilina mutabilis, a recently described bryozoan from Japan with sightings in Sweden, Norway, and Maine (US), to test how fast and far it has expanded across Europe in recent years. J. mutabilis settles easily on ship hulls, making it a useful model organism for studying long-distance invasion pathways. The study was conducted using Autonomous Reef Monitoring Structures (ARMS) to monitor the entire European coastline and Svalbard for J. mutabilis using DNA metabarcoding. During the time between its first sighting in Europe 2008 and the last ARMS retrieval 2020, the data shows how J. mutabilis has gained a pan-European distribution, being genetically identified in 14 new distinct locations. Presence/absence of barcodes were confirmed by image-based identification in 74% of the samples. Fourteen haplotypes never reported before were discovered in a 264 bp region of the cytochrome oxidase I gene. Two haplotypes (HP1 and HP3) occurred frequently and geographically widely dispersed, indicating intercontinental connectivity. Two locations, Koster and Getxo showed particularly high genetic diversity with similar haplotype networks suggesting continuous gene flow across oceanographically unlinked regions. Given the recent description of J. mutabilis and the relatively few historical encounters, the genetic diversity described here suggests an unusually fast range expansion within the last two decades. Such global spreading events of fouling organisms may become more common in the future as a result of more frequent and interconnected ship traffic. [ABSTRACT FROM AUTHOR]

The performance of fouling control coatings (FCC) is evaluated based on static exposure on test sites worldwide. There are different standards concerning the evaluation of the performance of the FCC. However, to the knowledge of the authors, there is not a standardized reporting guideline for how to evaluate the test site in which the FCC is exposed. Several factors such as water conditions, seasonal biofouling, and accessibility of sunlight can vary dependent on placement within or between test sites. This in turn makes it difficult to compare the performance of FCC exposed at different locations within a or at another test site. In this study, an analysis of the CoaST Maritime Test Centre (CMTC) has been performed to investigate how geographical orientation and changes in depth influence the biofouling propensity on coated panels. The investigation showed no statistical significance in the biofouling propensity between panels exposed to different geographical orientations at the CMTC. Similarly, no statistical significance was found between panels placed at different depths at the CMTC. If similar reporting was performed at other test sites, a better basis for comparison of FCC worldwide would be obtained, and this could be achieved with a standardized reporting guideline. [ABSTRACT FROM AUTHOR]

DCOIT (4,5-dichloro-2-n-octyl-4-isothiazolin-3-one) is the main ingredient in SeaNine-211, a new antifouling agent that replaces organotin compounds to prevent the growth of fouling organisms on board. Biocides from antifoulants can cause problems for marine ecosystems by destroying non-target algal species. This study evaluated the potential adverse effects DCOIT using the Marine Chlorella sp. The concentration of DCOIT were set according to the semi-inhibitory concentrations for acute exposure experiments, and relevant oxidative stress indicators were measured to assess the acute toxic effects. The results showed that the inhibition concentrations (IC50) of DCOIT against Marine Chlorella sp was 2.522 mg/L. The genes related to photosynthesis and antioxidant capacity showed the effect of promoting low concentration and inhibiting high concentration. In addition, based on the ultrastructural observation and the expression analysis of photosynthesis related genes, it was found that DCOIT had a significant effect on plant photosynthesis. [ABSTRACT FROM AUTHOR]

Although it is well known that microbes play a significant role in marine corrosion, few studies have systematically studied the relationship between microorganisms and corrosion products under long-term immersion. In this study, the corrosion characteristics of the rust layer formed on carbon steel immersed in the South China Sea for 5.5 years were investigated using various surface analysis and microbial community analysis techniques. Magnetite (Fe3O4), iron sulfide, and green rust were identified in the inner rust layer. The middle rust layer was composed of maghemite (γ-Fe2O3), and some Fe3O4 and mackinamite were also detected. The outer rust layer contained several Fe(III)-oxyhydroxides, and it had a large number of fouling organisms attached to it. In all of the rust layers, anaerobic sulfate-reducing bacteria (SRB) were the dominant bacteria, and they may have played a key role in the formation of the corrosion products. One SRB strain (Desulfovibrio bizertensis SY-1) with a highly corrosivity (13.561 mg/cm2) was isolated from these rust layers, and its physiological and metabolic characteristics were studied. These results expand the membership of corrosive SRB and establish a better understanding of marine microbiologically influenced corrosion (MIC). [ABSTRACT FROM AUTHOR]

In the early stages after larval settlement, coral spat can be rapidly overgrown and outcompeted by algae, reducing overall survival for coral reef replenishment and supply for restoration programs. Here we investigated three antifouling (AF) coatings for their ability to inhibit algal fouling on coral settlement plugs, a commonly-used restoration substrate. Plugs were either fully or partially coated with the AF coatings and incubated in mesocosm systems with partial recirculation for 37 days to track fouling succession. In addition, settlement of Acropora tenuis larvae was measured to determine whether AF coatings were a settlement deterrent. Uncoated control plugs became heavily fouled, yielding only 4–8% bare substrate on upper surfaces after 37 days. During this period, an encapsulated dichlorooctylisothiazolinone (DCOIT)-coating was most effective in reducing fouling, yielding 61–63% bare substrate. Antiadhesive and cerium dioxide (CeO2−x) nanoparticle (NP) coatings were less effective, yielding 11–17% and 2% bare substrate, respectively. Average settlement of A. tenuis larvae on the three types of AF-coated plugs did not statistically differ from settlement on uncoated controls. However, settlement on the NP-coating was generally the highest and was significantly higher than settlement found on the antiadhesive- and DCOIT-coating. Furthermore, on plugs only partially-covered with AF coatings, larval settlement on coated NP- areas was significantly higher than settlement on coated antiadhesive- and DCOIT-areas. These results demonstrate that AF coatings can reduce fouling intensity on biologically-relevant timescales while preserving robust levels of coral settlement. This represents an important step towards reducing fine-scale competition with benthic fouling organisms in coral breeding and propagation. [ABSTRACT FROM AUTHOR]

Antifouling paints incorporate biocides in their composition seeking to avoid or minimize the settlement and growing of undesirable fouling organisms. Therefore, biocides are released into the aquatic environments also affecting several nontarget organisms and, thus, compromising ecosystems. Despite global efforts to investigate the environmental occurrence and toxicity of biocides currently used in antifouling paints, the specific active ingredients that have been used in commercial products are poorly known. Thus, the present study assessed the frequencies of occurrence and relative concentrations of biocides in antifouling paint formulations registered for marketing worldwide. The main data were obtained from databases of governmental agencies, business associations, and safety data sheets from paint manufacturers around the world. The results pointed out for 25 active ingredients currently used as biocides, where up to six biocides have been simultaneously used in the examined formulations. Cuprous oxide, copper pyrithione, zinc pyrithione, zineb, DCOIT, and cuprous thiocyanate were the most frequent ones, with mean relative concentrations of 35.9 ± 12.8%, 2.9 ± 1.6%, 4.0 ± 5.3%, 5.4 ± 2.0%, 1.9 ± 1.9%, and 18.1 ± 8.0% (w/w) of respective biocide present in the antifouling paint formulations. Surprisingly, antifouling paints containing TBT as an active ingredient are still being registered for commercialization nowadays. These results can be applied as a proxy of biocides that are possibly being used by antifouling systems and, consequently, released into the aquatic environment, which can help to prioritize the active ingredients that should be addressed in future studies. [ABSTRACT FROM AUTHOR]

Microbiologically influenced corrosion (MIC) and biofouling in the marine environment are two main mechanisms of marine corrosion. The present review summarizes the results of recent studies and demonstrates that both MIC and marine biofouling are closely related to biofilms on the surface of materials formed by marine microorganisms and their metabolites. As a result, to prevent the emergence of MIC and biofouling, it is important to control microorganisms in biofilms or to prevent adhesion and formation of biofilms. The present review describes research approaches involving the use of new materials and innovative technologies in combination with traditional chemicals to achieve longer-lasting effects with the least environmental pollution due to the emerging synergistic effect. [ABSTRACT FROM AUTHOR]

Clionaid boring sponges (Cliona sp.) may affect individual oyster growth and condition while destroying oyster habitats, which can impact restoration efforts and aquaculture for eastern oysters (Crassostrea virginica). Since both oysters and boring sponges are affected by similar abiotic variables (i.e., salinity, tidal exposure), this study explored the potential trade-offs between these abiotic variables and sponge presence on growth, condition index, and survival of oysters using a fully-factorial in situ experiment across 3 sites in coastal GA, USA. Across all sites and tide heights, oysters with sponge grew 20% slower and had 10% lower condition index than oysters without sponge. Savannah State, the site with the lowest salinity (mean ± SD = 24.5 ± 2.1, range 20–28), exhibited growth rates that were 1.4–1.7 times faster than the other two sites, with even sponge-infested oysters exhibiting higher growth rates than uninfested oysters at the other two sites. In addition, growth rates of sponge-infested oysters were reduced by 26% relative to uninfested individuals in the low intertidal tier, but only by 12% in the upper intertidal zone, suggesting the negative impact also varies with tidal location. Therefore, oysters exposed to air for prolonged periods and placed in areas with polyhaline salinity exhibit fast growth and high relative condition index, although salinity may be confounded by other variables (food availability, fouling organisms). This study highlights the importance of considering site and tidal location for oyster restoration and culture. [ABSTRACT FROM AUTHOR]

In this study, we investigate the main ecological interactions between fouling aquatic organisms (both invasive and native) present in the reservoir of the Governador José Richa hydroelectric plant, located in southern Brazil, and to identify the most suitable period for the interruption of machinery operation for cleaning and maintenance of the hydraulic systems of this plant. A total of 32 experimental plates were fixed to a metallic structure positioned close to the plant's water intake. Three species of invasive fouling were identified in our samples (Limnoperna fortunei [Mollusca], Cordylophora sp., and Hydra sp. [Cnidaria]) and six native taxa belonging to the phyla Protozoa, Ciliophora, Amoebozoa, and Arthropoda. Spring and summer were the seasons with the highest fouling rates, as well as densities of fouling organisms. The highest levels of diversity were recorded during the colder seasons. Several interactions between the organisms were identified, such as mutualism, commensalism, competition, epibiosis, cannibalism, and predation. The data obtained suggest that, from the biological point of view, the most suitable period for machine shutdown destined for the removal of biological fouling in the hydraulic systems of the studied plant is between the end of spring and the beginning of summer. [ABSTRACT FROM AUTHOR]

Community assembly relies on deterministic niche-based processes (e.g., biotic interactions), and stochastic sources of unpredictable variation (e.g., colonization history), that combined will influence late-stage community structure. When community founders present distinct functional traits and a colonization–competition trade-off is not operating, initial colonization can result in late-stage assemblages of variable diversity and composed by different species sets, depending if early colonizers facilitate or inhibit subsequent colonization and survival. By experimentally manipulating the functional identity of founders and predators access during the development of fouling communities, we tested how founder traits constrain colonization history, species interactions and thereby regulate community diversity. We used as founders functionally different fouling organisms (colonial and solitary ascidians, and arborescent and flat-encrusting bryozoans) to build experimental communities that were exposed or protected against predation using a caging approach. Ascidians and bryozoans are pioneer colonizers in benthic communities and also good competitors, but the soft-body of ascidians makes them more susceptible to predators than mineralized bryozoans. When ascidians were founders, their dominance (but not richness) was reduced by predation, resulting in no effects of predators on overall diversity. Conversely, when bryozoans were founders, both space limitation and predator effects resulted in species-poor communities, with reduced number and cover of ascidian species and high overall dominance at the end of the experiment. We, thus, highlight that current species interactions and colonization contingencies related to founder identity should not be viewed as isolated drivers of community organization, but rather as strongly interacting processes underlying species distribution patterns and diversity. [ABSTRACT FROM AUTHOR]

Biofouling has been reported to be both harmful and innocuous on the growth and survival of cultured bivalves. If harmful, it could increase the operational cost substantially in an attempt to mitigate it. The study investigated the effect of sedentary biofoulers on the growth and survival of Crassostrea tulipa cultured on coconut shell and oyster shell cultches in the Densu Delta, Ghana, from December 2017 to July 2018. Physico-chemical parameters were monitored. Environmental temperature (26.4 ± 0.07 °C–29.5 ± 0.50 °C) and pH (7.2 ± 0.01–8.8 ± 0.01) were found to be within optimum levels for oyster propagation. The low levels of salinity (0.2 ± 0.01 ‰) and DO (0.6 ± 0.01 mg/l) and high turbidity (31.4 ± 2.91 NTU) could explain the observed high mortality of cultured oysters in July 2018. The observed fouling organisms were Fistubalanus pallidus (barnacle), Brachidontes sp. (mussel), Ficopomatus sp. (tube worm), Chaetomorpha antennina (green alga), and sea anemone. Oysters cultured on the undersurface of biofouled oyster shell cultches exhibited significantly faster growth than their cleaned counterparts but comparable on the upper surfaces of the cultches. The growth of cultured oysters on biofouled coconut shell cultches exhibits faster but insignificant growth than the oysters on cleaned cultches. There was no significant difference between the survival of oysters cultured on biofouled and cleaned coconut shell and oyster shell cultches. Marketable size oysters (≥ 6 cm shell height) are attainable in 7 to 8 months for both treatments. It was concluded that biofouling had no deleterious effect on the growth and survival of oysters. Besides, given the preferred shucked oysters in the Ghanaian market, it is inessential to incur further cost to control biofoulers. [ABSTRACT FROM AUTHOR]

Offshore wind farms (OWFs) act as artificial reefs, attracting high abundances of fish, which could potentially increase their local production. This study investigates the feeding ecology of fish species that abundantly occur at artificial habitats, such as OWFs, by examining the short- and the long-term dietary composition of five species: the benthopelagic Gadus morhua and Trisopterus luscus, the pelagic Scomber scombrus and Trachurus trachurus, and the benthic Myoxocephalus scorpioides. We conducted combined stomach content and stable isotope analyses to examine the short- and the time-integrated dietary composition, respectively. Our results indicated that benthopelagic and benthic species utilize artificial reefs, such as OWFs, as feeding grounds for a prolonged period, since both analyses indicated that they exploit fouling organisms occurring exclusively on artificial hard substrates. Trachurus trachurus only occasionally uses artificial reefs as oases of highly abundant resources. Scomber scombrus does not feed on fouling fauna and therefore its augmented presence in OWFs is probably related to reasons other than the enhanced food availability. The long-termed feeding preferences of benthic and benthopelagic species contribute to the hypothesis that the artificial reefs of OWFs could potentially increase the fish production in the area. However, this was not supported for the pelagic species. [ABSTRACT FROM AUTHOR]

The nanoparticles-based, multilayer, nanocomposite films ZnO, Cu2O, zinc borate, and Econea® were fabricated on cationized ultra-high molecular weight polyethylene (UHMWPE) fishing nets using a layer-by-layer molecular self-assembly technique. For the cationic surface charge, the UHMWPE fishing nets were pretreated with polyethyleneimine using the dip-coating method. Scanning electron microscopy and energy-dispersive X-ray spectroscopy were used to examine the nano-ZnO, Cu2O, zinc borate, and Econea® multilayer films deposited on the fishing nets. The fishing nets were placed in a fish farm located in the Aegean Sea for 6 months. The nano-Econea® films exhibited excellent antifouling activity against microorganisms. To evaluate the effect of the process on antifouling properties, physical tests of the nets were conducted before and after the nanoparticle treatment. The strength of the nets and fouling organisms were examined after the field study. [ABSTRACT FROM AUTHOR]

Macroalgae host a dense bacterial epibiome forming surface biofilms, which act as a biological defense by protecting the surface from macrofoulers. During experimental cultivation of Halymenia floresii (Rhodophyta, Halymeniales) under Integrated MultiTrophic Aquaculture (IMTA), the culture tanks remained clean of any exogenous algal colonization, and the surface of the H. floresii thalli was remarkably free from any fouling organisms. The presence of Halymenia also appeared to restrict the establishment of opportunist green algae and the colonization of barnacles usually impairing the cultures. To date, nothing is known about the diversity and biological potential of H. floresii epibionts. Hence, to better understand their epiphytic bacterial community, surface-associated bacteria from distinct H. floresii samples, beach-cast, integrated multi trophic aquaculture cultivar, and cultivar cylinders, were isolated. Thirty-one axenic bacterial strains belonging to 3 phyla, 20 genera, and 25 species were identified by 16S rRNA gene sequencing. Following isolation, they were screened for the production of quorum sensing (QS) signals, since these communication signals play a vital role in biofilm formation. All, except one, isolates were identified as gram-negative; hence, acylated homoserine lactones (AHLs) were focused upon. Using the reporter strain Escherichia coli pSB406, the isolates were screened for their ability to induce luminescence. Of 31 isolates screened, 17 strains, including Pseudoalteromonas arabiensis, Pseudoalteromonas sp. (B5BC and B6.1BC), Pseudoalteromonas mariniglutinosa, Vibrio owensii, Tenacibaculum sp., Maribacter sp., Spongiimicrobium salis, Aquimarina sp., Kordiimonas sp., Alteromonas sp. (B12CC and B16CC), Roseobacter sp., Erythrobacter sp., Ruegeria lacuscaerulensis, and Epibacterium sp., exhibited the presence of extracellular QS signals. Thus, the presence of QS bacteria on the surface of H. floresii was demonstrated for the first time. Our results may open a new direction to investigate the host—QS bacteria interactions. [ABSTRACT FROM AUTHOR]

Paint coatings based on a copolymer of vinyl chloride with vinyl acetate with an additive of epoxy-diane resin of six different compositions are developed. The coatings differ in the nature of fillers (anatase, rutile, and cobalt and lanthanum oxides) and the composition of soft biocidal additives of the atrane class (protatrane of salicylic acid and hydrometallatranes based on triethanolamine complexes with zinc(II) and copper(II) salts). The process of biofouling in the natural conditions of the White sea is studied. Fouling communities formed on the studied plates during 2.5 months of exposure to the sea is analyzed, depending on the composition of the coatings. The fouling is based on the attached forms: scyphistomas (polypoid stage) of jellyfish Aurelia aurita and Cyanea sp., mussels Mytilus edulis, and hydroid Obelia longissima. The efficiency of the same paint coating appear to differ towards different species of fouling organisms. [ABSTRACT FROM AUTHOR]

Marine biofouling remains an unsolved problem with a serious economic impact on several marine associated industries and constitutes a major vector for the spread of non-indigenous species (NIS). The implementation of biofouling monitoring programs allows for better fouling management and also for the early identification of NIS. However, few monitoring studies have used recent methods, such as metabarcoding, that can significantly enhance the detection of those species. Here, we employed monthly monitoring of biofouling growth on stainless steel plates in the Atlantic Port of Leixões (Northern Portugal), over one year to test the effect of commercial anti-corrosion paint in the communities. Fouling organisms were identified by combining morpho-taxonomy identification with community DNA metabarcoding using multiple markers (16S rRNA, 18S rRNA, 23S rRNA, and COI genes). The dominant colonizers found at this location were hard foulers, namely barnacles and mussels, while other groups of organisms such as cnidarians, bryozoans, and ascidians were also abundant. Regarding the temporal dynamics of the fouling communities, there was a progressive increase in the colonization of cyanobacteria, green algae, and red algae during the sampled period with the replacement of less abundant groups. The tested anticorrosion paint demonstrated to have a significant prevention effect against the biofouling community resulting in a biomass reduction. Our study also reports, for the first time, 29 NIS in this port, substantiating the need for the implementation of recurring biofouling monitoring programs in ports and harbours. [ABSTRACT FROM AUTHOR]

A serious consequence of marine biofouling on metallic structures is the insidious localized corrosion at the attachment sites of fouling organisms, such as barnacles. Albeit known, this phenomenon is poorly understood and currently mitigated using cost- and labor-intensive methods. In this work, we study the contribution to biofouling corrosion by a protein contained in the adhesive cement that barnacles secrete to attach to immersed substrates. We synthesize a specific cement protein of 20 kDa (CP20) from the barnacle Megabalanus rosa and study its corrosion behavior independently of the animal. Our results show that CP20 accelerates the corrosion rate of a marine-grade, mild steel from 0.7 to 1.6 mm year−1. Through chemical analysis of the corrosion products, protein adsorption studies on the metal surface, and cyclic voltammetry, we elucidate an intricate corrosion mechanism that relies on the strong adhesive properties of CP20 and its electrochemically active disulfide groups. Our results have far-reaching implications on the prediction and mitigation of biocorrosion in marine applications. Moreover, the protein-induced corrosion mechanism unveiled in our study may be extended to other scenarios to understand the degradation of metal alloys used in food storage and biomedical implants. [ABSTRACT FROM AUTHOR]

The adhesion of diatoms to a substrate occurs through the secretion of extracellular polymeric substances (EPS), which is conducive to the growth of other fouling organisms, including barnacles and oysters attached to the diatom surface [[9]]. Furthermore, B 11 b , B 13 b , and B 14 b also displayed broad antidiatom activities against I C. socialis i , I N. leavissima i , and I N. parva i , which indicated that polyhydroxyl substitution of flavones can increase antidiatom activity (Fig. The organic extracts were subjected to silica gel column chromatography (CC) eluted by a gradient of petroleum ether (PE)-EtOAc to EtOAc, and then MeOH to afford five fractions (Frs. [Extracted from the article]

A series of indole-1-carboxylic acid aryl esters was synthesized with indole and substituted phenols as raw materials. The structures of the target compounds were validated by IR and 1H-NMR spectroscopies. The inhibitory activities of the target compounds and their potencies against marine fouling organisms were investigated. The results showed that the target compounds had significant inhibitory effects on the growth of three seaweeds: Isochrysis galbana, Platymonas subcordiformis, and Navicula, and the target compounds also had excellent inhibition on the survival of barnacle larvae. The substituent structure–activity relationships revealed a significant effect on biological inhibition activity: Compounds substituted by electron-withdrawing groups had greater bioactivities than those containing electron-donating groups. Release rate of antifoulant and marine field tests indicated the final compounds had an outstanding antifouling potency against marine fouling organisms. [ABSTRACT FROM AUTHOR]

Predicting the effects of invasive ecosystem engineering species in new bioregions has proved elusive. In part this is because separating biological effects from purely physical mechanisms has been little studied and yet could help predict potentially damaging bioinvasions. Here we tested the effects of a large bio-engineering fanworm Sabella spallanzanii (Sabella) versus worm-like structures (mimics) on gas and nutrient fluxes in a marine soft bottom sediment. Experimental plots of sediment in Hauraki Gulf (New Zealand) were used to test the hypothesis that ecosystem engineers negatively influence benthic ecosystem function through autogenic mechanisms, facilitating activity by biofouling organisms and competitive exclusion of native infauna. Enhanced physical structure associated with Sabella and mimics increased nitrogen fluxes, community metabolism and reduced denitrification from 23 μmol m−2 h−1 to zero at densities greater than 25 m2. Sabella plots on average had greater respiration (29%), NH4 release (33%), and greater NO3 release (52%) compared to mimics, suggesting allogenic (biological) mechanisms occur, but play a secondary role to autogenic (physical) mechanisms. The dominance of autogenic mechanisms indicates that bio-engineers are likely to cause significant impacts when established, regardless of fundamental differences in recipient regions or identity of the introduced bio-engineer. In the case of Sabella spallanzanii, compromised denitrification has the potential to tip the balance of net solute and gas exchanges and cause further ecological degradation in an already eutrophic system. [ABSTRACT FROM AUTHOR]

Although marine biofouling has been widely studied on different substrates, information on biofouling on plastics in the Arabian Gulf is limited. Substrate- and location-specific effects were investigated by comparing the microbial communities developed on polyethylene terephthalate (PET) and polyethylene (PE) with those on steel and wood, at two locations in the Sea of Oman. Total biomass was lower on PET and PE than on steel and wood. PET had the highest bacterial abundance at both locations, whereas chlorophyll a concentrations did not vary between substrates. MiSeq 16S ribosomal RNA sequencing revealed comparable operational taxonomic unit (OTU) richness on all substrates at one location but lower numbers on PET and PE at the other location. Non-metric multidimensional scaling (NMDS) showed distinct clusters of the bacterial communities based on substrate (analysis of similarity (ANOSIM), R = 0.45–0.97, p < 0.03) and location (ANOSIM, R = 0.56, p < 0.0001). The bacterial genera Microcystis and Hydrogenophaga and the diatoms Licmophora and Mastogloia were specifically detected on plastics. Desulfovibrio and Pseudomonas spp. exhibited their highest abundance on steel and Corynebacterium spp. on wood. Scanning electron microscopy (SEM) revealed fissure formation on PET and PE, indicating physical degradation. The presence of free radicals on PET and carbonyl bonds (C=O) on PE, as revealed by Fourier transform infrared (FTIR) spectroscopy, indicated abiotic degradation while hydroxyl groups and spectral peaks for proteins and polysaccharides on PE indicated biotic degradation. We conclude that fouling microbial communities are not only substrate-specific but also location-specific and microbes developing on plastics could potentially contribute to their degradation in the marine environment. [ABSTRACT FROM AUTHOR]

This chapter provides a context and perspective to consider novel materials for use in fouling management. Fouling and biofouling are defined and the rationale for existing fouling management is provided. Fouling management in even benign environments is difficult because commercial approaches use broadspectrum stable biocides with non-target effects on humans, environmental health, and food safety. These historic approaches target death as the only biological endpoint. If novel approaches are to be implemented, biological alternatives to broad-spectrum long-lived biocides must be discovered, designed, and fitted within existing business models, infrastructures, and regulatory frameworks. The title, "Candy and Poisons", highlights the two major issues for sustainable fouling management. Potent, short-lived toxins and pharmacophores, protected in coatings and chemically and biologically destroyed, are eaten as is candy within hours to days after release. Fouling on roofs as an example of an extreme environment and speculation about the use of conserved biological pathways in fouling management are discussed. Major concerns for all fouling management approaches are humans, environmental health, and food safety. With novel approaches, health and food safety should be addressed at the beginning of the technology development. The most difficult hurdle that a new technology faces is the regulatory framework. Present regulatory structures repress new technology and are slowly reducing options for the highly toxic management approaches. Policy changes that support novel technologies and close loopholes for long-lived toxins are needed to stimulate environmentally appropriate solutions. [ABSTRACT FROM AUTHOR]

The main objective of this review is to discuss the recent research on polymer-based surface coatings contributing to the protection against marine biofouling based on the knowledge available in literature, supplemented by means of figures, mechanism illustrations, mathematical models, and equations. A need for studies on the mathematical behavior of such coatings is emphasized, composed of quantitative evaluation of foul-release performance of coatings using mathematical equations of the concerned parameters. Apart from the synthesis of protective polymeric coatings, understanding the relationship between characteristics of coating materials and accompanying foul-release and antifouling mechanism is important. In this regard, efforts have been made to equally evaluate, simulate, and measure the appropriate performance of the coatings. By examining the physicochemical and mechanical properties of the polymers, adhesion behavior has been found to be one of the prerequisites for the success of polymeric coatings for marine applications. The potential development of a broad spectrum of methods used to evaluate the foul-release performance of polymeric coatings depending on adhesion behavior of fouling organisms with the coatings has been discussed. From the analysis of the factors affecting degradation of coatings, environmental interference is declared a key factor for complete degradation of polymeric coatings. This review opens up new research directions to improve the adhesion performance of polymeric coatings for ship hulls designed with tunable viscoelasticity by the incorporation of elastomeric polymers (like polydimethylsiloxane) into stiff polymers (like epoxy resins) with and without the utilization of additives, modifiers, and nano-fillers. In addition, it provides methods to improve the foul-release performance of such coatings that work on adhesion behavior of biofouling species attached to the coating surface. [ABSTRACT FROM AUTHOR]

The susceptibility of native and non-native populations of the red alga Gracilaria vermiculophylla to fouling was compared in common garden experiments. Native and non-native algae were enclosed into dialysis membrane tubes, and the tubes were exposed to natural fouling. Fouling on the outside of the tubes was mediated by chemical compounds excreted by G. vermiculophylla that diffused through the membranes. Fouling pressure was significantly higher in the Kiel Fjord (non-native range) than in Akkeshi Bay (native range), but, at both sites, tubes containing non-native G. vermiculophylla were less fouled than those with native conspecifics. This is the first in situ evidence that susceptibility to fouling differs between native and non-native populations of an aquatic organism. The technique of enclosing organisms into dialysis tubes represents a simple, efficient and accurate way to test chemical antifouling defenses and could possibly be applied to other organisms. [ABSTRACT FROM AUTHOR]

Coral-reef community structure has generally changed following declines in coverage by reef-building organisms. Ascidians as fast-growing, filter-feeding organisms, are of concern due to their invasiveness potential, but few studies have examined their life-history traits in tropical environments. The present study examined the distribution, settlement patterns, and reproductive cycle of the solitary, hermaphroditic ascidian Halocynthia spinosa in Eilat, Red Sea (29°30′N, 34°55′E), from August 2013 to August 2015. This species has a native distribution in the western Indian Ocean, with a continuous presence along the southern and eastern coasts of Africa. In Eilat, the field survey found that H. spinosa was prevalent in shallow depths, on cryptic, shaded substrates. Histological analysis of spermatogenesis and oogenesis, and a determination of the gonad index in monthly samples revealed a seasonal reproductive cycle that was significantly correlated with seawater temperature, associated with photoperiod and food availability. All measures of reproduction showed the highest activity in the summer (June-August), and a short resting period in the winter months (December-March). H. spinosa individuals were rarely observed on artificial structures. Thus, the introduction of H. spinosa into new regions as part of a fouling community is relatively unlikely. These findings contribute to understanding ecological interactions of non-reef-building organisms such as ascidians, and add to the knowledge of ascidian reproductive patterns. [ABSTRACT FROM AUTHOR]

Mytilus galloprovincialis is a major fouling organism in the inter-tidal zone. However, the interactions between M. galloprovincialis plantigrade settlement, biofilm characteristics, and surface wettability remains unknown. Here, we examined M. galloprovincialis plantigrade settlement responses to marine biofilms (BFs) on surfaces of varying wettability. No significant difference in mussel settlement was observed on young BFs (7 d) on surfaces of differing wettability; while settlement decreased on older BFs (14, 21, and 28 d) formed on low compared to high wettability surfaces. Surface wettability affected BF characteristics. The standardized harmonic mean and water contact angles values were not correlated with diatom density and chlorophyll a concentration, but were correlated with bacterial density, dry weight, and thickness. Denaturing gradient gel electrophoresis revealed that bacterial community structure differed on BFs on surfaces of varying wettability. Thus, surface wettability affects biofilm characteristics, and the subsequent changes in BF characteristics may be responsible for the variation in biofilm-inducing activity of M. galloprovincialis plantigrade settlement. [ABSTRACT FROM AUTHOR]

Prevention of annual 'green tides' caused by blooms of the green macroalga Ulva prolifera, which have occurred in the Yellow Sea since 2007, has received much attention. Increasing evidence indicates that micro-propagules on the rafts used for Porphyra yezoensis aquaculture along the coastline of Jiangsu Province in China, were the primary source of these green tides. In this study, we investigated the effectiveness of a silicone antifouling coating for preventing the adhesion and germination of U. prolifera micro-propagules on bamboo and nylon ropes, which have been used in rafts for P. yezoensis aquaculture. Our results demonstrated that a coating of silicone (Sylgard 184) containing 1.0 wt.% sodium benzoate (NaB) could reduce the adhesion rate to <5% and completely inhibited the growth of U. prolifera propagules on the coated surfaces. Coating bamboo and nylon ropes with NaB-incorporated silicone thus proved a potentially effective method for controlling the initial biomass accumulation of U. prolifera. [ABSTRACT FROM AUTHOR]

The ability of the sponge Halichondria panicea to assimilate into the fouling communities of the blue mussel Mytilus edulis and the solitary ascidian Styela rustica has been studied in a field experiment, in which sponge fragments have been introduced artificially into epibenthic communities. The growth of H. panicea was suppressed greatly in the presence of young mussels; its survival rate averaged 40%. In the communities where S. rustica dominated, the survival rate of H. panicea reached 100%, but the growth rate was lower than in the control group (without competitor species). Despite the high natural growth rate and toxicity, the settlement success of H. panicea was low on the substrate occupied by another fouling species. [ABSTRACT FROM AUTHOR]

Predatory control of community structure, through consumption of herbivores and subsequent positive effects on the biomass or productivity of primary producers is common in marine ecosystems. We designed an experiment to analyse the effect of large-sized predators on the development of the macrofouling assemblage of a harbour. Predation was manipulated by randomly assigning artificial substrata to three treatments: (1) exclosure cages preventing access of large predators, (2) cage controls, i.e. cages with lateral walls but without roofs, allowing predators free access, (3) uncovered panels. Substrata were submersed horizontally and upper surfaces sampled at quarterly intervals over a 1-year period. No differences in species richness were observed among treatments but diversity was lower within exclosure cages than on cage controls/uncovered panels. In sessile assemblages, structure differed between treatments: cage controls/uncovered panels were dominated by algae and associated mesoherbivores, which were scarce/absent within cages. Exposure to predators also affected the structure of mobile assemblages. The sea urchin Pseudechinus magellanicus (Philippi) occurred within exclosure cages but was never found on exposed panels. We conclude that large predators exert a significant effect on assemblage structure and diversity, indirectly promoting the development of filamentous algae and mesoherbivores by controlling the abundance of browsers. [ABSTRACT FROM AUTHOR]

This study assessed the influence of summer seawater temperature and shipping on the introduction, establishment, and spread of nonindigenous fouling species on both local and regional scales in coastal regions of the USA. Using photographic surveys of 80 marinas on the east and west coasts of the USA, we defined thermal niches and ranges of summer sea surface temperature (SSST) for 27 abundant fouling species. We calculated percent cover of all abundant tunicates and bryozoans across sites and correlated species richness with water temperature and cargo shipping volume in each region. We quantified the relative importance of cargo shipping, seawater temperature, and distance between sites using Jaccard similarity between paired sites. Native species richness was positively correlated with SSST, while nonindigenous species (NIS) richness displayed a parabolic relationship with a peak at 20 °C. Temperature and cargo shipping traffic explained 53 % of variability in NIS richness, and only temperature was correlated with similarity between sites. We also found no link between similarity and distance between sites, and site-site comparisons showed no effect of NIS on native species richness on the scale of this study. It appears that cargo shipping may play a regional role in introduction of new species, but on local scales NIS distributions are more haphazard, possibly driven by local recreational boat traffic and associated larval dispersal or by other vectors affecting the local spread of these species. Our study demonstrates the importance of seawater temperature in allowing spread of NIS and influencing similarity between sites and regions. [ABSTRACT FROM AUTHOR]

A novel dead-end mode operation for filtering anaerobic suspensions was investigated. In this mode, the filtration system automatically adjusted backwashing frequency to a preselected transmembrane pressure set-point. This paper discusses the effectiveness of the backwashing conditions on membrane fouling. Anaerobic suspensions from a conventional wastewater treatment plant digester were used as model suspensions for the trials carried out at lab-scale. Gas sparging aided backwashing significantly enhanced membrane cleaning efficiency. No effect of gas sparging on internal fouling was detected. Also, the cleaning efficiency linearly decreased with permeate flux. Nevertheless, due to a high increase in the reversible fouling, a reasonable net permeate flux (7.2-6.8 L/h m) can be achieved when intermediate fluxes (12-16 L/h m) were imposed and the higher transmembrane pressure set-point value (50 kPa) was applied. Both backwashing duration and flux exhibited similar influence on cake fouling removal for a given volume of permeate produced. [ABSTRACT FROM AUTHOR]

Mytilopsis sallei is a small marine bivalve and is considered as a serious pest. We assume that the invasive bivalve M. sallei changed the community structure of fouling macrofauna and reduced the species diversity index in Yundang Lagoon, Xiamen, China. In order to verify the above hypothesis, test panels were submerged seasonally at five stations during four seasons in Yundang Lagoon, and some chemical parameters were determined. The results showed there were significant differences in density and biomass of M. sallei and other fouling macrofauna with season and with station. The species diversity of the macrofaunal fouling community at stations B and F was low in summer, because high density of M. sallei was found at two stations. There were significantly positive correlations between density and biomass of M. sallei and water temperature and COD, and significantly negative correlations with pH. The results confirmed that this invasive species changed the density and biomass compositions of fouling macrofauna, reduced the species diversity index during the summer period, and somewhat worsened the aquatic environmental quality in Yundang Lagoon, because the pH and the DO were the lowest, and the BOD and the COD were the second lowest in summer among four seasons. [ABSTRACT FROM AUTHOR]

Drip irrigation systems using reclaimed water often present clogging events of biological origin. Microbial communities in biofilms from microirrigation systems of an experimental greenhouse in Almería, SE Spain, which used two different qualities of water (treated wastewater and reclaimed water), were analyzed by denaturing gradient gel electrophoresis and subsequent sequencing of amplified 16S rRNA gene bands. The most remarkable feature of all biofilms was that regardless of water origin, sequences belonging to Firmicutes were prevalent (53.5 % of total mean band intensity) and that almost all sequences recovered had some similarity (between 80.2 and 97 %) to thermophilic microorganisms. Mainly, sequences were closely related to potentially spore-forming organisms, suggesting that microbial communities able to grow at high temperatures were selected from the microbiota present in the incoming water. These pioneer results may contribute to improve management strategies to minimize the problems associated to biofouling in irrigation systems. [ABSTRACT FROM AUTHOR]

Bacterial biofilm communities formed on different membrane surfaces were investigated based on 16S rRNA gene sequence analysis. The biofilm communities were distinct from those of mixed-liquor and consisted mainly of Beta- and Gammaproteobacteria. Sequences of Xathomonas and Aquabacterium were mostly retrieved from the biofilm samples rather than from the mixed liquor. Furthermore, statistical analyses demonstrated the importance of a physico-chemical property of membrane, surface roughness, in structuring the bacterial biofilm communities. [ABSTRACT FROM AUTHOR]

There exists a possibility of leaching out of chemicals along with preservative components from chemically treated wood on exposure to water or moisture. Physical barriers have gained much acceptance in this regard as alternative non-biocidal wood protection method as it is supposed to reduce leaching and subsequent negative impacts of wood preservative components to the organisms in vicinity. Fibreglass reinforced plastic (FRP) and epoxy paint was coated over chromated copper arsenate (CCA) treated rubber wood panels and exposed in Cochin estuary for 18 months. Total wet weight biomass and numerical abundance of five most abundant group of foulers viz. hydroids, polychaetes, crustaceans including wood borers, barnacles and bivalves on these panels were studied. Copper, chromium and arsenic concentration in tissues and shells of barnacles were also analyzed. Results indicated significantly high biomass and numerical abundance of foulers on physically protected panels than untreated and preservative treated ones. Physical barriers significantly reduced accumulation of metals in barnacles indicating possibility of reduced leaching. Study can be considered as a lean to the impact studies conducted world over regarding the use of CCA for marine applications. However, CCA treated rubber wood as core material for FRP boats can be a better option as it poses less adverse effect on organisms in the vicinity. [ABSTRACT FROM AUTHOR]

We review the species composition, distribution, and seasonal variation of fouling acorn barnacles in Chinese waters-from Bohai Sea and Yellow Sea to East and South China Seas. Thirty-two species of acorn barnacles were found, of which, the dominant species are Amphibalanus amphitrite, A. reticulatus, A. variegates, Balanus trigonus, Fistulobalanus kondakovi, Megabalanus tintinnabulum, Striatobalanus amaryllis, and Eurapha withersi in the fouling communities. A. amphitrite is the dominant species in the coastal waters of Bohai Sea and Yellow Sea and A. reticulatus is dominant in the East and South China Seas. The settlement period of fouling acorn barnacles is usually in summer and autumn. From north to south with the decrease of latitude, their settlement period obviously extends, even to the whole year, and the species number also increases. Other environmental factors, such as salinity and distance from shore, also play an important role in the distribution of fouling acorn barnacles. [ABSTRACT FROM AUTHOR]

Biofouling in aquatic environments have a wide range of detrimental effects on man-made structures and cause economic loss. Current antifouling compounds including Diuron, dichlorofluanid, and Irgarol are toxic and can accumulate in marine environments. Thus, effective and environmentally friendly antifoulants are needed. Six structurally similar compounds were isolated from the brown alga, Sargassum horneri, based on bioactivity-guided isolation by reversed-phased liquid flash chromatography and high-performance liquid chromatography. Six chemical constituents possessing antifouling activities were identified as chromanols consisting of polyprenyl chain by nuclear magnetic resonance and mass spectroscopy. Antifouling activities of these six compounds were determined against representative fouling organisms including a hard fouling organism the mussel Mytilus edulis, a soft fouling macroalga Ulva pertusa, the biofouling diatom Navicula annexa, and the biofouling bacteria Pseudomonas aeruginosa KNP-3 and Alteromonas sp. KNS-8. The compounds could inhibit larvae settlement of mussel M. edulis with an EC of 0.11-3.34 μg mL, spore settlement of U. pertusa zoospores (EC of 0.01-0.43 μg mL), and the diatom N. annexa (EC of 0.008-0.19 μg mL). The two biofouling bacteria were sensitive to the tested compounds (minimum inhibitory concentration of 1.68-36.8 and 1.02-30.4 μg mL, respectively). From toxicity tests on juvenile Sebastes schlegelii fish, brine shrimp Artemia salina, and microalga Tetraselmis suecica, S3 had the lowest LC values of 60.2, 108, and 6.7 μg mL and exhibited no observed effect concentration at 24.5, 41.6, and 3.1 μg mL for these three tested marine organisms, respectively. [ABSTRACT FROM AUTHOR]

Mass collection of germlings and growth of fouling algae are two main constraints for the seedling production of Sargassum thunbergii. In this study, 65% and 40% of reproductive output (allocation of biomass to sexual reproductive tissue) for farmed and natural populations respectively, were recorded during peak reproduction. In terms of germlings per kilogram wet weight of plants, the farmed population gave a higher yield than the natural population (3.2 × 10 and 1.2 × 10 germlings kg, respectively). These results indicate that farmed populations could be used as parental plants for germling collection in seedling production. During the experiment, fouling was controlled by jet washing and high-density seeding. A germling detachment of less than 10% was observed when, after 48 h of attachment, collectors were jet-washed with an intensity of 1 kg cm. High-density seeding had adverse effects on length mean, size equality, and occurrence of branches of germlings. However, 30-50 individuals cm are thought to be usable in the seedling production of S. thunbergii because of less density effects. Seedlings of > 0.5 cm length could be achieved after 1 month of tank culture. [ABSTRACT FROM AUTHOR]

The structure of fouling communities formed by the sponge Halichondria panicea in the White Sea is described. On artificial substrates exposed in the sea for a long time, this sponge forms overgrowths on the colonies of long-lived organisms such as the mussel Mytilus edulis or the ascidian Styela rustica. The biomass of algae and sedentary animals (other than H. panicea) on the substrate is markedly smaller in areas colonized by this sponge than in neighboring sponge-free areas. Conversely, the biomass of both sedentary and errant polychaetes is greater in H. panicea colonies than in adjacent fouling communities. [ABSTRACT FROM AUTHOR]

We surveyed the distribution of colonies of polyps of Aurelia aurita sensu lato ( s.l.) in Mikawa Bay, Japan. First, we surveyed the distribution of ephyrae of A. aurita s.l. at 75 stations encompassing the whole of Mikawa Bay in early 2008. A total of 37 ephyrae were sampled mostly from fishing ports. Ephyrae were most abundant around the islands located near the mouth of the bay, and decreased from the western part to the eastern part of Mikawa Bay. Next, we selected five fishing ports in Mikawa Bay where ephyrae occurred and surveyed the underside of floating piers and underwater overhangs of wharfs. We found dense colonies of polyps of A. aurita s.l. under nearly all of the floating piers at the two islands located near the mouth of the bay. Fitting a logistic regression model to the dataset showed that the percentage coverage of Aurelia polyps was significantly greater at the two islands compared with the other locations. In addition, the coverage of Aurelia polyps was greater when the coverage of other fouling organisms was in the range of 65-90%, and the coverage of Aurelia polyps was lower on floating piers with a vinyl surface and on concrete wharfs. The combined distribution of polyp colonies of A. aurita s.l. in Ise Bay and Mikawa Bay suggested that A. aurita s.l. in the two bays probably forms a single population and shoals of medusae mainly originate from protected harbors along the mouth-part of the bays. [ABSTRACT FROM AUTHOR]

A biosensor for the determination of alcohol based on cysteine (Cys) nanolayers has been constructed. The utilization of the redox-inactive, self-assembled monolayer (SAM) modified gold ultra micro-electrode (UME) for NADH electroanalysis is introduced as a new modified gold Cys-UME. This Cys-UME prevents fouling and was found to be stable and ill-defined under subsequent potential sweeps, and different NADH concentrations. NADH oxidation gave a linear correlation between the peak current and NADH concentration (1–5 mM). Also, excellent electro-catalytic activity (enhancing the oxidation peak current) was observed towards NADH oxidation, with activation overpotential of about 250 mV lower than that of the bare electrode. The use of different alcohol concentrations in the presence of alcohol dehydrogenase (ADH) gave an increase in the NADH oxidation peak current, indicating that the electrochemical NADH oxidation at mild potentials could lead to an enzymatically active NAD+. [ABSTRACT FROM AUTHOR]

We examined the species composition of red king crab ( Paralithodes camtschaticus) fouling communities in Dolgaya Bay, a small fjord of the Barents Sea, in August 2005 and 2006. In total, there were 13 species observed on 301 crabs collected from water depths of 5–90 m. Barnacles ( Balanus crenatus; prevalence 42.9%) and blue mussels ( Mytilus edulis; 11.6%) were the most common epibionts, while amphipods ( Ischyrocerus commensalis) were the most common symbionts (28.6%). Infestation rates in Dolgaya Bay were different from those in an “open” area of the Barents Sea (Dalnezelenetskaya Bay), probably due to differences in hydrodynamic conditions. Differences in infestation prevalence and intensity were detected neither between male and female crabs nor between crabs collected at 5–35 m versus 90 m depths. Prevalence of common fouling species increased with host size. Amphipods I. commensalis colonized the carapace and limbs in Dolgaya Bay less frequently than in Dalnezelenetskaya Bay, probably due to interspecific competition with barnacles occupying the dorsal parts of the host. Juvenile barnacles and mussels dominated the fouling communities on the crabs. The age of barnacles did not exceed 2–4 months. However, the presence of 4-year-old mussels suggests that these older mollusks have been directly transferred from mussel beds to the hosts. Our results indicate that colonization by epibionts and symbionts is generally not disadvantageous for the crab hosts, except for some possible negative impacts of amphipods occupying the gills. [ABSTRACT FROM AUTHOR]