Tesis sobre el tema "Fouling organisms"
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1
Nylund, Göran M. "Chemical mediation of fouling in seaweeds /". Göteborg : Göteborg University, Department of Marine Ecology, 2005. http://www.loc.gov/catdir/toc/fy0701/2006388585.html.
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Yang, Lai Hung. "Antifouling compounds from the marine sponge acanthella cavernosa and its associated microbes /". View abstract or full-text, 2006. http://library.ust.hk/cgi/db/thesis.pl?AMCE%202006%20YANG.
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Wieczorek, Sabine Katharina. "Effects of marine microfouling on the establishment of subtidal hard substratum communities". Thesis, University of St Andrews, 1996. http://hdl.handle.net/10023/13820.
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Sessile marine invertebrate larvae can recognize suitable settlement substrata by using various environmental cues, including organic/microbial "biofilms". In laboratory assays the effect of biofilm age on the settlement of a range of fouling species was assessed: the species included barnacle, bryozoan, spirorbin and ascidian larvae. The larvae of most species responded differentially to films of varying ages. A general trend of reversal of the effect of filming on the settlement response of the barnacle Balanus amphitrite amphitrite- from inhibitory to facilitatory - was noted with increasing film age. The settlement of the solitary ascidian Ciona intestinalis clearly was facilitated on filmed substrata of all ages. The larvae of the arborescent bryozoan Bugula flabellata generally were inhibited by biofilming (irrespective of film age), and the settlement of the polychaete Spirorbis spirorbis was found to be enhanced on "older" (12d) films only. In a series of manipulative panel experiments in a tidal rapid on the west coast of Scotland the effects of biofilming on subsequent larval settlement in the field were quantified. Inhibitory and facilitatory responses to biofilming were noted and these varied markedly between species and between two local habitats of contrasting flow regimes. The larvae of certain year-round settling species were found to vary in their response to biofilmed substrata depending on the season. Quantitative data were obtained for biofilms on artificial substrata by enumerating bacteria, diatoms, protozoans, fungi and the percent cover of microbial exopolymeric substances. These permitted comparisons of biofilms both in field and laboratory experiments. The results of the present study emphasize the importance of microbial surface film cues in explaining recruitment patterns of macrofouling assemblages during the first stages of substratum colonization.
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Scott, Caroline Daphne. "The role of blue-green algae as marine fouling organisms". Thesis, University of Portsmouth, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.282555.
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Larsson, Ann. "Flow effects on settlement and recruitment in the barnacle : balanus improvisus with applications for biogouling control /". Göteborg : Dept. of Marine Ecology, Göteborg University, 2006. http://www.loc.gov/catdir/toc/fy0706/2006411323.html.
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Larsson, Ann. "Flow effects on settlement and recruitment in the barnacle Balanus improvisus with application for biofouling control /". Göteborg : Göteborg University, Department of Marine Ecology, 2006. http://www.loc.gov/catdir/toc/fy0706/2006411323.html.
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Afsar, Anisul Biological Earth & Environmental Sciences Faculty of Science UNSW. "Settlement of marine fouling organisms in response to novel antifouling coatings". Publisher:University of New South Wales. Biological, Earth & Environmental Sciences, 2008. http://handle.unsw.edu.au/1959.4/40927.
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Surfaces submerged in marine environments rapidly get colonized by marine organisms, a process known as biofouling. Fouling costs maritime industries billions of dollars annually. The most common methods of combating marine biofouling are toxin containing antifouling coatings which often have detrimental non-target environmental effects. These effects and proposed bans on harmful substances in antifouling coatings, mandates development of more environmentally friendly antifouling technologies. Of these, foul-release coatings, which minimize attachment and adhesion of fouling organisms (rather than killing them) are promising alternatives. Here I explored the utility of petroleum waxes as novel antifouling/foul-release coatings. I first investigated the responses of propagules (larvae or spores) of six common fouling organisms to wax coatings in the laboratory. A wide variation in the response of these different organisms, and in the different types of response (settlement, adhesion, etc.) by the same organism, was observed, but the most inhibitory coatings were those made from microcrystalline wax and silicone oil. However, in field trials in Sydney Harbour, paraffin waxes had the strongest antifouling performance, with activity up to one year (the trial duration). These waxes also had strong foul-release effects, with fouling that did attach mostly removed by a low pressure water jet. Composition of fouling communities on paraffin waxes differed significantly from other waxes or controls, with little or no hard fouling organisms (barnacles, bivalves) on paraffin. The mechanisms of antifouling and foul-release actions of paraffin waxes appear to be due to changes in surface properties. The surfaces of the paraffin waxes changed noticeably after 4 - 8 weeks immersion in the sea or in seawater aquaria. Antibiotic treatments showed that this change in surface appearance was due to biological (microbial) activity. Bacteria appear to remove the amorphous phase from the surface of the paraffin waxes, revealing an underlying crystalline phase, which is less affected by bacterial action. I suggest that these crystals form a microstructured ?bed of nails? of crystals of varying shapes and sizes which inhibit settlement and reduce adhesion strength of those organisms which do settle.
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Huang, Yi-Li. "Potential roles of bacterial quorum sensing and biofilm formation in the biofouling process /". View abstract or full-text, 2007. http://library.ust.hk/cgi/db/thesis.pl?AMCE%202007%20HUANG.
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Stec, Lara Zoe. "Microfiltration of micro-organisms : the effect of the extracellular matrix on fouling". Thesis, University of Bath, 2001. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.343776.
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Mai-Prochnow, Anne Gerda Erna Biotechnology & Bio-molecular Sciences UNSW. "Autolysis in the development and dispersal of biofilms formed by the marine bacterium Pseudoalteromonas tunicata". Awarded by:University of New South Wales. Biotechnology and Bio-molecular Sciences, 2006. http://handle.unsw.edu.au/1959.4/25537.
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The marine bacterium Pseudoalteromonas tunicata produces target-specific inhibitory compounds against bacteria, algae, fungi and invertebrate larvae and is frequently found in association with living surfaces in the marine environment. This study examined the ability of P. tunicata to form biofilms under continuous culture conditions within the laboratory. P. tunicata biofilms exhibited a characteristic architecture consisting of differentiated microcolonies surrounded by water-channels. Interestingly, a repeatable pattern of cell death in the centre of microcolonies was observed. The antibacterial and autolytic protein, AlpP, produced by P. tunicata was found to be involved in this biofilm killing and a
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Hou, Huiyi y 侯慧仪. "Marine biofouling organisms respond to multiple stressors in a changing climate". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hdl.handle.net/10722/194551.
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The marine environment is likely to experience profound climate change in the coming 100 years and beyond. Ocean acidification (OA) is one of the climate change issues attracting the attention of researchers all over the world. The decreasing pH of the oceans might threaten marine biofouling organisms. However, climate change is not only involved with ocean acidification (OA) but the change of other environmental variables, such as temperature and salinity. These environmental factors act as multiple stressors and synergistically affect shell-forming biofoulers, in which, the calcium carbonate skeleton structure plays an important role of protection. Previous studies regarding the response of marine biofoulers to the environmental stressors were generally summarized in this article. Then a calcifying biofouling tube worm, Hydroides elegans, were reared from larval stage to early juvenile stage under control and treatment conditions to examine the combined effects of temperature (24, 30°C), pH (8.1, 7.7) and salinity (34, 27ppt). Juvenile growth and chemical composition (Mg/Ca and Sr/Ca) of their calcareous tubes were tested and used as assessment of effects of the three environmental stressors. The experiment revealed that H. elegans was robust to the environmental change because juvenile development positively responded to temperature and the interaction between temperature and salinity. Other combinations did not exert significant effect. The results suggest the need of further study of proteomics and transcriptomics to reveal the mechanisms of calcification as well as long-term studies to examine the energy costs of adaptation. In addition, the non-significant chemical composition (Mg/Ca and Sr/Ca) of the tube of this organism suggest a need of further exploration of the same animal but not only focus on three factors but the seawater chemical composition as well.published_or_final_version
Environmental Management
Master
Master of Science in Environmental Management
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Giannantonio, David John. "Molecular Characterization of Microbial Communities Fouling Concrete Infrastructures". Thesis, Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/24797.
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The objective of this study was to identify and characterize naturally-occurring communities of Bacteria and Fungi fouling the surfaces of concrete structures in Georgia, USA, through the use of culture-independent and culture-dependent approaches. Genomic DNA was extracted and ribosomal RNA genes were PCR amplified from 4 biofouled sites located in or around the cities of Atlanta, Gainesville, LaGrange, and Savannah. Bacterial and fungal community composition was determined by phylogenetic analysis. Molecular analysis revealed five bacterial phyla, and representatives of the phylum Cyanobacteria and the classes Betaproteobacteria and Gammaproteobacteria dominated the bacterial clone libraries. Fungal clone libraries showed the dominant phylotypes to be most closely related to Alternaria, Cladosporium, Epicoccum and Udeniomyces. Phylogenetically distinct microbial populations were present at each of the biofouled sites. In addition, cultured isolates were obtained from sites and tested for their ability to foul concrete of varied compositions under laboratory-controlled conditions. Biofouling tests revealed that fungal isolates obtained from the field were able to colonize concrete surfaces when supplied with moisture (95-100% relative humidity) and a nutrient source, and that fouling was affected by concrete water/cement ratio, surface roughness, and the presence of photocatalytically-activated cement added to inhibit microbial growth.
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Mant, Rebecca Catherine. "The control of encrusting organisms within drinking water treatment works". Thesis, University of Cambridge, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.608989.
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Roscoe, Donald Thomas. "Settlement and bioadhesion of two marine fouling organisms, Pomatoceros lamarckii and Laminaria digitata". Thesis, Bangor University, 1993. https://research.bangor.ac.uk/portal/en/theses/settlement-and-bioadhesion-of-two-marine-fouling-organisms-pomatoceros-lamarckii-and-laminaria-digitata(9562d900-7365-4a9d-b6fa-1ed8dfc38a90).html.
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An investigation of certain aspects of the biology of Pomatoceros lamarckii and Laminaria digitata was carried out with particular reference to the factors influencing the settlement of P. lamarckii larvae and to the bioadhesion of both species. The larvae of P. lamarckii were found to be negatively phototaxic throughout their development. A distinctive pattern of settlement behaviour was observed and as the larvae settled they became attached to the substratum by a mucus pad situated in the region of the ventral shield epithelium. Larvae settled gregariously on and close to conspecific adults, but the presence of conspecific juveniles did not induce settlement. Unsuccessful attempts were made, using whole and parts of animals and tubes in a range of solvents, to isolate a chemical settlement stimulus and it was concluded that it is highly unlikely that a chemical cue is produced by P. lamarckii adults. Biofilming was found to be the major factor in inducing settlement and it was demonstrated that substrata biofilmed in the presence of P. lamarckii adults attracted significantly more settlers than did substrata biofilmed in other ways. The adult mediated biofilms were found to contain large numbers of a rod-shaped bacterium which was present only in very low numbers in the other biofilms and it is proposed that this bacterium, or its exopolymers, may provide the primary settlement stimulus. Natural settlement was examined on pebbles at three different locations and the results compared with the laboratory findings. Tenacity was measured for the tubes of P. lamarckii and the haptera of L. digitata. A mean tenacity of 24.75 x 1()5 ± 6.7 N m-2 was recorded for P. lamarckii and a mean tenacity of 4.21 x 1()5 ± 1.9 N m-2 was recorded for L. digitata.
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McClees, Whitney Elizabeth. "Anthropogenic Effects on the Fouling Community: Impacts of Biological Invasions and Anthropogenic Structures on Community Structure". PDXScholar, 2017. https://pdxscholar.library.pdx.edu/open_access_etds/3883.
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Coastal anthropogenic infrastructure has significantly modified nearshore environments. Because these structures often have a strong association with shipping as would be found in ports and harbors, they have been identified as invasion hotspots. Due to propagule pressure from shipping and recreational boating and suitable uncolonized substrate that provides a refuge from native predators, a greater number of non-native species have been found on these structures compared to nearby natural substrate. The mechanisms that limit the spread of non-native species from anthropogenic structures to natural substrate have been explored for several taxa at a species-specific level, but less so from an overall community perspective. Predation has been identified as one of the biotic interactions limiting invasion success. In addition to predation, dispersal ability may also prevent the spread of non-native species from anthropogenic structures to natural substrate.
This thesis addresses how these two mechanisms interact to limit the spread of non-native species from anthropogenic structures to natural substrate and how that alters overall community composition. I aimed to explore differences between communities inside and outside of a marina and determine the extent to which predator and dispersal limitation were structuring these communities. I used a three-factor design, deploying seven unglazed ceramic tiles per each treatment combination of 1) inside versus outside a marina in Yaquina Bay, Oregon; 2) cage keeping out predators greater than the mesh size, no cage, or partial cage; 3) fixed near the substrata (benthic) versus suspended 1 meter below the surface. I also transplanted caged, suspended tiles of either adults or recruits from inside the marina to benthic and suspended caging treatments outside of the marina. These tiles allowed me to examine predation when dispersal limitation was not a factor for the community inside the marina, i.e. what happens to both recruits and adults if they can get outside of the marina. I found that the communities inside and outside of the marina were different and the data suggest that both predation and dispersal limitation interact to limit the spread of non-native species. Additionally, I found that mesopredators that could fit through the caging may be influencing predation results and community structure.
This research addresses gaps in scientific knowledge regarding the mechanisms that prevent or facilitate the spread of non-native species. Future work could include the further exploration of mesopredation as an important factor in limiting the spread of non-native species and exploring dispersal limitation more in depth as well as broadening the geographic scope to see if the same trends hold true across bays and bioregions.
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Stelzer, Sacha Biotechnology & Biomolecular Sciences Faculty of Science UNSW. "WmpR regulation of antifouling compounds and iron uptake in the marine bacterium Pseudoalteromonas tunicata". Awarded by:University of New South Wales. School of Biotechnology and Biomolecular Sciences, 2006. http://handle.unsw.edu.au/1959.4/29354.
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The dark-green pigmented marine bacterium Pseudoalteromonas tunicata produces several extracellular compounds against a range of common fouling organisms including bacteria, fungi, protozoa, diatoms, invertebrate larvae and algal spores. The regulator WmpR, which has N-terminal similarity to ToxR from Vibrio cholerae and CadC from Escherichia coli, controls all of the pigment and antifouling phenotypes. These compounds appear at the onset of stationary phase. The role of WmpR as a stationary phase regulator in P. tunicata was investigated in this thesis. Starvation and stress studies demonstrated that WmpR does not appear to control genes necessary for survival during carbon, phosphate or nitrogen starvation and UV/hydrogen peroxide stress. Intriguingly, phosphate starvation caused pigmentation of wmpR mutant (D2W2) logarithmic phase cells, suggesting a second regulation of the pigments (and thus antifouling compounds) that could be mediated by the PhoR/B twocomponent regulatory system. Proteomic analysis using two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) found that 11 proteins were differentially regulated by WmpR, and the identities of some of these proteins suggested a role for WmpR as a general stationary phase regulator rather than a specific starvation or stress regulator. Gene expression studies using RNA-arbitrarily primed PCR introduced a new role for WmpR as a regulator of iron acquisition; a TonB-dependant outer membrane receptor gene and a non-ribosomal peptide synthetase (NRPS) gene were up-regulated in the stationary phase Wt strain compared to the D2W2 strain. An assay for iron-binding activity supported the proposal that the NRPS may be making a siderophore. Further studies demonstrated that WmpR is required for survival under long-term low-iron conditions and that the pigments and antifouling genes are down-regulated during low-iron, while biofilm formation is up-regulated. WmpR also appears to constitutively regulate the production of iron-binding compounds, a novel regulation of iron acquisition that has not been seen in other organisms studied so far. A model is proposed that describes WmpR as responding to environmental signals, including iron, and co-ordinating the expression of a complex regulon including a number of genes involved in iron acquisition, general stationary phase physiology and bioactive secondary metabolite production.
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Li, Honglei. "Investigation of genes involved in larval attachment and metamorphosis of biofouling species hydroides elegans and balanus amphitrite /". View abstract or full-text, 2007. http://library.ust.hk/cgi/db/thesis.pl?AMCE%202007%20LI.
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Bao, Wei-wei Vivien. "Toxicities and ecological risks of selected anti-fouling biocides to marine organisms in Hong Kong". Click to view the E-thesis via HKUTO, 2009. http://sunzi.lib.hku.hk/hkuto/record/B43085180.
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Bao, Wei-wei Vivien y 鮑薇薇. "Toxicities and ecological risks of selected anti-fouling biocides to marine organisms in Hong Kong". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2009. http://hdl.handle.net/10722/210298.
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Dijkstra, Jennifer Anne. "Climate change and invasive species interact to impact succession and diversity in Gulf of Maine marine fouling communities /". Restricted access (UM), 2007. http://libraries.maine.edu/gateway/oroauth.asp?file=orono/etheses/37803141.pdf.
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Xu, Ying. "Antifouling compounds from deep-sea bacteria and their potential mode of action /". View abstract or full-text, 2009. http://library.ust.hk/cgi/db/thesis.pl?BIOL%202009%20XU.
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Sevak, Hamel P. "Potential chemical defenses against diatom fouling in macroalgae from the Antarctic Peninsula insights from bioassay guided fractionation /". Birmingham, Ala. : University of Alabama at Birmingham, 2010. https://www.mhsl.uab.edu/dt/2009m/sevak.pdf.
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Mann, Maryssa Gudrun Ailsa. "An investigation of the antimicrobial and antifouling properties of marine algal metabolites". Thesis, Rhodes University, 2008. http://hdl.handle.net/10962/d1007465.
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Prevention of the accumulation of undesirable biological material i.e. biofouling upon a solid surface requires the use of antifouling systems. The solid surface may be a contact lens, an off shore oil rig or a living organism. When chemicals are employed as a mechanism of defense against biofouling, the agents involved are known as antifouling agents. Marine algae must protect themselves from fouling organisms and it is thought that one of the mechanisms used by these organisms is the production of secondary metabolites with an array of biological activities. In vitro studies have shown numerous compounds isolated from marine algae to possess antibacterial, antifungal and antimacrofouling activity. The aim of this study was to evaluate the secondary metabolite extracts of selected Southern African marine macro-algae as a potential source of compounds that inhibit biofilm formation and that could be used as antifouling agents. In this project, marine macro-algae were collected from various sites along the South African coastline. Their extracts were screened for antimicrobial activity against four ubiquitous microorganisms, Staphylococcus aureus, Klebsiella pneumoniae, Mycobacterium aurm and Candida albicans. Results of screening assays guided the fractionation of two Rhodophyta, Plocamium corallorhiza and Laurencia flexuosa. The algae were fractionated using silica gel column chromatography and compounds were isolated by semi-preparative normal phase HPLC. Compound characterization was performed using UV, IR and advanced one- and two-dimensional NMR (¹H, ¹³C NMR, COSY, HSQC, HMBC and NOESY) spectroscopy and mass spectrometry. Ten halogenated monoterpenes including four members of the small class of halogenated monoterpene aldehydes were isolated from extracts of P. corallorhiza. The compounds isolated included the known compounds 3,4,6,7-tetrachloro-3,7-dimethyl-1-octene; 4,6-dibromo-1, 1-dichloro-3,7 -dimethyl-2E,7 octadiene; 4,8-d ibromo-1,1,7 -trichloro-3, 7-dimethyl-2,5Eoctadiene;1 ,4,8-tribromo-3, 7 -dichloro-3,7-dimethyl-1 E,5E-octadiene; 8-bremo-6, 7-dichloro-3,7-dimethyl-octa-2E,4E-dienal; 4-Bromo-8-chloro-3,7-dimethyl-octa-2E,6E-dienal; 4,6- Dibromo-3,7-dimethyl-octa-2E,7-dienal; 2,4-dichloro-1-(2-chlorovinyl)-1-methyl-5-methylidene-cyclohexane and two new metabolites 4,8-chloro-3,7-dimethyl-2Z,4,6Z-octatrien-1-al and Compound 3.47. Methodology was developed for the chemical derivatization and mass spectrometric analysis of the aldehydic compounds, The aldehyde trapping reagent 0-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine hydrochloride was used to derivatize the molecules, stabilizing them and allowing for their complete characterization. From Laurencia flexuosa a new cuparene sesquiterpene 4-bremo-2-(5-hydroxy-1,2,2- trimethylcyclopent-3-enyl)-5-methylphenol was isolated along with two geometric isomers of the vinyl acetylene bromofucin , An halogenated monoterpene 3S*,4R*-1-bromo-3,4,8-trichloro-9-dichloromethyl-1-E,5-E,7-Z-octatriene was also isolated but was suspected to be a contaminant and an investigation into its biological source revealed that it originated from Plocamium suhrii. A third alga, Martensia elegans was extracted based on published reports of antimicrobial compounds in related species. A new a-alkyl malate derivative was isolated and characterized. Selected compounds isolated during the course of the study were employed in preliminary assays that tested their ability to inhibit biofilm formation by Pseudomonas aeruginosa. The halogenated monoterpenes isolated from the Plocamium species were the only active compounds. 3S*,4R*-1-bromo-3,4,S-trichloro-g-dichloromethyl-1-E,5-E,7-octatriene from P. suhrii inhibited biofilm formation through antibacterial activity on planktonic cells but could not prevent biofilm formation when employed as a film on the surface of microtitre plate wells. 1,4,8-tribromo-3,7-dichloro-3,7-dimethyl-1E,5E-octadiene and 4,6-dibromo-1,1-dichloro-3,7-dimethyl-2E,7-octadiene inhibited biofilm formation when applied as a film to the microtitre plate wells but had no significant antibacterial activity. No potential antifouling agents were identified in this project but the antimicrobial activity exhibited by the crude algal extracts was highly encouraging and a number of new research areas have been identified.KMBT_363
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Miao, Li. "Potential antifouling compounds of marine-derived fungi from Hong Kong". online access from Digital Dissertation Consortium, 2006. http://libweb.cityu.edu.hk/cgi-bin/er/db/ddcdiss.pl?3239505.
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Egan, Suhelen Microbiology & Immunology UNSW. "Production and regulation of fouling inhibitory compounds by the marine bacterium Pseudoalteromonas tunicata". Awarded by:University of New South Wales. Microbiology and Immunology, 2001. http://handle.unsw.edu.au/1959.4/17838.
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The marine surface-associated bacterium Pseudoaltermonas tunicata, produces a range of compounds that inhibit fouling organisms, including invertebrate larvae, bacteria, algal spores and fungi. In addition to these antifouling compounds P. tunicata cells produce both a yellow and a purple pigment. The aim of this study was to further characterise the antifouling activities, their regulation and relationship with pigmentation, and the ecological significance of P. tunicata and related organisms. It was discovered that the anti-algal compound was extracellular, heat sensitive, polar and between 3 and 10 kDa in size. The anti-fungal compound was found to be the yellow pigment and active against a wide range of fungal and yeast isolates. Chemical analysis suggests that this compound consists of a carbon ring bound to a fatty-acid side chain. Genetic analysis supports the chemical data for the active compound as a mutant in a gene encoding for a long-chain fatty-acid CoA ligase was deficient for anti-fungal activity. To address the regulation of antifouling compounds and their relationship to pigmentation transposon mutagenesis of P. tunicata was performed. Mutants lacking the yellow pigment displayed a reduced ability to inhibit fouling organisms. Further analysis of these mutants identified genes involved with the synthesis and regulation of synthesis of pigment and antifouling compounds. One of these mutants was disrupted in a gene (wmpR) with similarity to the transcriptional regulators ToxR from Vibrio cholerae and CadC from Escherichia coli. Analysis of global protein expression using two-dimensional gel electrophoresis showed that WmpR is essential for the expression of at least fifteen proteins important for the synthesis of fouling inhibitors. The ecological significance of antifouling bacteria was addressed by assessing the antifouling capabilities of a collection of bacteria isolated from different marine surfaces. Overall, isolates from living surfaces displayed more antifouling traits then strains isolated from non-living surfaces. Five dark-pigmented strains originating from the alga Ulva lactuca were further studied. Phylogenetic and phenotypic analysis revealed that they were all members of the genus Pseudoalteromonas and were closely related to P. tunicata. Two strains represented a novel species within the genus and were taxonomically defined as P. ulvae sp. nov.
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Wong, Yuen-yee Queenie. "Mariculture practices in relation to water quality and the nearshore marine environment in Hong Kong /". Hong Kong : University of Hong Kong, 2000. http://sunzi.lib.hku.hk/hkuto/record.jsp?B22264188.
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Cheung, Kwok-wai. "Primary colonisation of submerged artificial substrates with special reference to marine macroalgae /". [Hong Kong : University of Hong Kong], 1986. http://sunzi.lib.hku.hk/hkuto/record.jsp?B12218029.
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Nylund, Göran M. "Epibiosis of red algae and algal metabolites as settlement inhibitors of the barnacle Balanus improvisus Darwin". Göteborg [Sweden] : Dept. of Marine Botany, Göteborg University, 1999. http://bibpurl.oclc.org/web/20311.
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Thesis (master's)--Göteborg University, 1999.Title from PDF t.p. (viewed on Sept. 25, 2007). At head of title: Tjärno Marine Biological Laboratory. Includes bibliographical references (p. 13-14).
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Kincaid, Erin Suzanne. "Biofouling Management in the Pacific Northwest and Predation on Native versus Non-native Ascidians". PDXScholar, 2016. http://pdxscholar.library.pdx.edu/open_access_etds/3069.
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Marine non-native species threaten economic and environmental health, making it crucial to understand factors that make them successful. Research on these species, therefore, allows for greater preparedness and informed management of biological invasions and increases understanding of elements structuring biological communities. Among the marine non-native species, and particularly the fouling community, non-native ascidians are a taxon of particular concern because they can crowd out native benthic species and smother mariculture products. This thesis addresses management for ascidians and other fouling organisms and includes research on the invasiveness of this taxon in addition to the invasibility of recipient fouling communities. On the West Coast of the U.S., limited efforts have been made to coordinate biofouling management across states, despite the myriad vectors increasing propagule pressure over time along coastal states. Building on recent state and local efforts, I developed a Pacific Regional Biofouling Plan for the states of Oregon and Washington to help start a consensus-driven process by which these states could create a forum for more comprehensive coordination efforts, following California's lead. As states address authority gaps, the biofouling management framework I've written is meant to be used to guide the conversation between managers as various stages of coastal management are realized.
To better inform the scope and efficacy of management and regulatory efforts, the study of invasions ecology asks and aims to answer questions regarding recipient community interactions and characteristics of the non-native species themselves. Studies that identify characteristics that make ascidians successful (invasiveness) and determine the influence native communities have on their success (invasibility) are important for assessing overall risk of establishment and spread from non-native ascidians. Therefore, I aimed to: 1) explore the hypothesis that fouling communities on suspended, artificial structures are more invasible than benthic habitats; and 2) identify characteristics influencing predation patterns on the native Distaplia occidentalis versus non-native ascidian species using mensurative and experimental studies in Charleston Marina, Oregon. I conducted a series of feeding assays, surveys, and a caloric content analysis. Feeding assays were conducted with a suite of predators. The flatworm predator (Eurylepta leoparda) was found to be highly selective on the native ascidian Distaplia occidentalis, and only preyed on whole colony samples. Feeding assay data suggest that test (tunic) structure or thickness may be an influential factor affecting nudibranch (Hermissenda crassicornis) predation rates on native versus non-native ascidians, with greater predation on the native ascidian species. Non-native ascidians may escape predation in floating but not benthic environments on the Oregon coast due to their palatability characteristics, likely tunic structure and low caloric content. In this case, this suite of predators may indirectly facilitate the invasion of docks but provide at least partial resistance to the invasion of natural benthic areas.
The chapters herein address gaps in management and scientific knowledge regarding non-native species of the marine fouling community. Future work enhanced by my efforts could include the development of the coastal biofouling management plan, coordinated by the Western Regional Panel on Aquatic Invasive Species Coastal Committee, and broadening the geographic and taxonomic scope of my research with a more comprehensive study of predator-prey interactions involving non-native ascidians and a diverse suite of predators. These interactions may be an important factor in explaining the success of ascidians and other fouling organisms on floating structures and lack of success on nearby benthic substrata.
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Nolting, Janine. "Proposed South African management framework for the implementation of the International Convention for the Control and Management of Ships' Ballast Water and Sediments". Thesis, Rhodes University, 2011. http://hdl.handle.net/10962/d1003907.
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South Africa, strategically situated at the southern tip of Africa, is edged on three sides by almost 3000 km of coastline surrounded by the Indian Ocean and the Atlantic Ocean (South African Tourism, 2011). This vast ocean expanse is responsible for conveying approximately 96% of South Africa’s exports (Brand South Africa, 2011). Despite the positive economic effects of the shipping industry, translocation of harmful organisms and pathogens via ballast water and sediments inside ballast water tanks has far reaching global environmental (and economic) impacts (Oliviera, 2008:1; David and Gollasch, 2008:1966). Ballast water is the water that is taken on in order to manage the draft of the ship, to help with propulsion, manoeuvrability, trim control, list and stability (Oliviera, 2008:2). The discharge of ballast water into the world’s oceans has resulted in the transfer of ecologically harmful sea-life into non-native environments (IMO, 2011), resulting in major environmental threats to our oceans (Bax, Williamson, Aguero, Gonzalez and Geeves, 2003:313). Various international documents have been developed to deal with the ballast water issue, culminating in the introduction of the International Convention for the Control and Management of Ships’ Ballast Water and Sediments (“the Convention”) in 2004. The Convention aims at achieving a reduction in the transfer and subsequent impacts of aquatic organisms via the ballast water and sediment of ships. On a local level, South Africa does not have direct legislation or regulations dealing with ballast water (Duncan, 2007:34) and relies on the combination of a number of pieces of legislation relating to environmental management, coastal management, biodiversity, alien invasive species control, port control and ship safety (National Environmental Management Act, 1998, National Environmental Management: Biodiversity Act, 2004, National Environmental Management: Integrated Coastal Management Act, 2009, National Ports Act, 2005 and Merchant Shipping Act, 1951). Although the Convention was ratified by South Africa in 2008 (Department of International Relations and Cooperation, 2011) it is still not in force and there still exists no other consolidated legal mechanism through which ballast water is managed. This research has investigated the various roles, responsibilities and mandates of South African competent authorities under the aforementioned legislation in managing ballast water, and has determined that there is definite legislative and institutional fragmentation as well as overlaps. A comparative analysis of management frameworks developed both locally and internationally was conducted in order to develop a management framework for ballast water management in South Africa. Various legislative, institutional and functional aspects were identified and adapted for inclusion in a South African management framework. A co-ordinated approach to ballast water management has been developed in the management framework which is anticipated to result in more definitive roles and responsibilities of the various South African departments involved in the management of ballast water and implementation of the Convention.
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Figueiredo, Joana Rita Monteiro. "Toxicity of novel anti-fouling nanomaterials in Marine organismsv". Master's thesis, Universidade de Aveiro, 2017. http://hdl.handle.net/10773/22019.
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Mestrado em Ecologia AplicadaBiofouling is an ecological succession of fouling communities in submerged surfaces that has extensive ecological, environmental and economic impacts worldwide when developed over man-made structures. In order to minimize this problem, biocides with anti-fouling properties are commonly used in protective coatings of submerged structures. Some decades ago, organotin compounds were used as effective anti-fouling agents, however they were completely banned in 2008 due to the toxic and biomagnification effects. As a consequence, a new generation of biocides were developed with lower toxicity and persistence in the environment when compared to organotin compounds. Recently, one of these biocides (DCOIT) was encapsulated in an engineered nanomaterial (silica mesoporous nanocapsules, SiNC-DCOIT) in order to prevent the interaction of biocides with coatings’ ingredients and control their leaching rate during the early lifetime of conventional paints, with environmental and economic benefits. The present study aimed to assess the toxicity of SiNC-DCOIT and a modified version of the engineered nanomaterial including two biocides, the SiNC-DCOIT coated with silver, to marine species and compare its toxicity with the free counterparts (empty SiNC, DCOIT and Ag). Ecotoxicity tests were carried out with eleven marine species, including bacteria (Vibrio fischeri), microalgae (Isochrysis galbana, Nannochloropsis gaditana, Phaeodactylum tricornutum), rotifers (Brachionus plicatilis), bivalves (Cerastoderma edule, Mytilus galloprovincialis), polychaetes (Hediste diversicolor), crustaceans (Artemia salina, Palaemon varians) and echinoderms (Paracentrotus lividus), following standard tests (with some adaptions in some cases). Acute or short-term chronic endpoints were used upon each species and adopted test. Globally, values of L/E/IC50 for SiNC-DCOIT, SiNC-Ag and SiNC-DCOIT-Ag were higher than the estimated values for DCOIT and silver (dissolved in solution), except for some target groups involved in the early fouling stages, proving that these alternative agents are more environmentally-friendly comparatively to free biocides. The obtained L/E/IC50 and NOEC values from the tested compounds were then used to create species sensitivity distributions together with data from literature. The HC5 and PNEC values derivated from these curves showed that the hazard of DCOIT and silver is reduced when encapsulated, highlighting these novel nanomaterials as a promising anti-fouling solution.
A bioincrustação é uma sucessão ecológica de comunidades incrustantes em superfícies submersas que tem extensos impactos ecológicos, ambientais e económicos em todo o mundo quando desenvolvida em estruturas artificiais. Para minimizar esse problema, os biocidas com propriedades anti-incrustantes são comummente utilizados em revestimentos protetores de estruturas submersas. Há algumas décadas atrás, os compostos organoestânicos eram amplamente utilizados como agentes anti-incrustantes eficazes, porém foram definitivamente banidos em 2008 devido a efeitos tóxicos e de biomagnificação reportados. Como consequência, foi desenvolvida uma nova geração de biocidas com menor toxicidade e persistência no meio ambiente em comparação com os compostos organoestânicos. Recentemente, um desses biocidas (DCOIT) foi encapsulado num nanomaterial manufaturado (nanocápsulas de sílica mesoporosas, SiNC-DCOIT), a fim de evitar a interação dos biocidas com os ingredientes dos revestimentos e controlar a sua taxa de libertação durante o início de vida das tintas convencionais, com benefícios ambientais e económicos. O presente estudo teve como objetivo avaliar os efeitos em diversas espécies marinhas do nanomaterial SiNC-DCOIT e de uma versão modificada deste, contendo dois biocidas (SiNC-DCOIT revestido com prata), e comparar a sua toxicidade com os componentes destes nanomateriais (SiNC vazias, DCOIT e Ag). Os testes de ecotoxicidade foram realizados com onze espécies marinhas, incluindo bactérias (Vibrio fischeri), microalgas (Isochrysis galbana, Nannochloropsis gaditana, Phaeodactylum tricornutum), rotíferos (Brachionus plicatilis), bivalves (Cerastoderma edule, Mytilus galloprovincialis), poliquetas (Hediste diversicolor), crustáceos (Artemia salina, Palaemon varians) e equinodermes (Paracentrotus lividus), seguindo testes padrão (com algumas adaptações em alguns casos) ou com protocolos bem definidos. Foram determinados parâmetros agudos ou crónicos de curta duração dependendo da espécie testada e do teste adotado. Globalmente, os valores de L/E/IC50 para SiNC-DCOIT, SiNC-Ag e SiNC-DCOIT-Ag foram superiores aos valores estimados para DCOIT e prata (dissolvidos em solução), com exceção de alguns grupos alvo envolvidos nos primeiros estádios de incrustação, provando assim que estes são agentes alternativos mais amigos do ambiente comparativamente aos biocidas livres. Os valores obtidos de L/E/IC50 e NOEC para os compostos testados foram depois utilizados para derivar curvas de distribuições de sensibilidade de espécies, juntamente com dados da literatura. Os valores HC5 e PNEC derivados dessas curvas mostraram que o perigo do DCOIT e da prata diminui quando encapsulados, destacando que estes nanomateriais inovadores parecem ser uma solução anti-incrustante promissora.
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Ujihara, Atsushi, Seiji Hayashi, 温. 氏原 y 誠司 林. "元寇沈没船周辺から得られた貝類及び船体付着貝類から見た当時の古環境と船の来歴". 名古屋大学年代測定資料研究センター, 2013. http://hdl.handle.net/2237/20148.
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Wong, Yuen-yee Queenie y 黃婉儀. "Mariculture practices in relation to water quality and the nearshore marine environment in Hong Kong". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2000. http://hub.hku.hk/bib/B30257487.
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Santos, Carla luciana Teixeira dos. "Colonização de organismos incrustantes em substrato artificial na região estuarina Lagoa dos Patos, sob influencia do fenômeno El ninõ". reponame:Repositório Institucional da FURG, 2011. http://repositorio.furg.br/handle/1/4173.
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Dissertação(mestrado) - Universidade Federal do Rio Grande, Programa de Pós–Graduação em Oceanografia Biológica, Instituto de Oceanografia, 2011.Submitted by Cristiane Gomides (cristiane_gomides@hotmail.com) on 2013-11-18T16:26:59Z No. of bitstreams: 1 Carla Luciana Teixeira dos Santos.pdf: 553016 bytes, checksum: 84c584008c6c713cd29f554d93509b29 (MD5)
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Foi analisada de julho de 2009 a junho de 2010 a variabilidade mensal e sazonal dos organismos incrustantes e perfurantes no estuário da Lagoa dos Patos, utilizando-se como substrato painéis de madeira. O período experimental foi marcado pela ocorrência do fenômeno El Niño (ENSO), tendo a primavera e o verão apresentado valores de salinidade abaixo das médias regionais, o que se refletiu em densidades muito baixas do cirripédio Balanus improvisus, no aparecimento do bivalvo de água doce Limnoperna fortunei, e na ausência de organismos perfurantes. Nestas situações de El Niño os padrões de assentamento e a variabilidade dessas comunidades se dão de maneira diferente da observada em situações de não ocorrência do fenômeno.
Monthly and seasonal variability of both fouling and boring macrobenthic fauna were analyzed from July 2009 to June 2010 inside the Patos Lagoon estuarine region, utilizing pine-wood panels as substrate. Sampling period was marked by the occurrence of an El Niño (ENSO) phenomenon, when spring and summer presented salinity values far below the regional means. This low salinity period determined extremely low densities of the barnacle Balanus improvisus, the occurrence of the fresh water invasive bivalve Limnoperna fortunei and the absence of boring species. Under El Niño situations, patterns of larvae settlement and consequent community variability are very different from that observed in periods of non-occurrence of this stochastic phenomenon.
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Karla, Pereira da Silva Andréa. "Estudo qualitativo da sucessão ecológica, recrutamento e do tratamento "anti-fouling" convencional em organismos incrustantes, na região portuária de Suape-Pernambuco, Brasil". Universidade Federal de Pernambuco, 2003. https://repositorio.ufpe.br/handle/123456789/8627.
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Previous issue date: 2003Conselho Nacional de Desenvolvimento Científico e Tecnológico
O fouling , processo de adesão, colonização e desenvolvimento de seres vivos ou materiais não vivos sobre um substrato submerso pode ser danoso quando se estabelece sobre estruturas construídas pelo homem. O conhecimento sobre os processos biológicos e ecológicos na comunidade incrustante, que apresenta características particulares de acordo com a situação geográfica e a dinâmica do ecossistema na qual a comunidade incrustante está inserida, representa um elemento indispensável para a busca por alternativas antiincrustantes eficientes e menos danosas ao meio ambiente, do que as técnicas convencionais utilizadas até o momento. Neste contexto, o presente trabalho teve como objetivo estudar a comunidade incrustante sobre substrato artificial submerso na região de Suape, litoral sul do Estado de Pernambuco, Brasil. Foram analisados os processos de sucessão ecológica, recrutamento, bem como a resposta ao tratamento com tinta anti-fouling convencional. O estudo foi realizado durante o período de outubro de 2001 a outubro de 2002, utilizando placas metálicas de controle (sem tintas), tratadas com zarcão comum e com tinta antiincrustante. As placas foram dispostas em fileiras contendo placas acumulativas, destinadas ao estudo da sucessão e placas mensais para acompanhamento do processo de recrutamento. Os resultados obtidos mostraram que a comunidade incrustante da Região de Suape possui mecanismos de sucessão típicos, compostos inicialmente por colonizadores unicelulares eucariontes que foram representados por uma densa cobertura de diatomáceas coloniais, seguidos do fouling propriamente dito, representado por cnidários, briozoários, poliquetas, moluscos, crustáceos e tunicados. Briozoários incrustantes e cirripédios foram os organismos mais freqüentes e abundantes. Ascídias coloniais recobrem superfícies logo no início do processo de colonização, dominando o espaço, mas devido ao curto ciclo de vida logo disponibilizam o substrato para outros colonizadores. Grupos de organismos menos expressivos formaram relações de epibioses, porém, mecanismos de defesa ou inibitórios impediram o desenvolvimento das epibioses sobre ascídias coloniais e briozoários incrustantes. Os parâmetros abióticos de salinidade e temperatura da água mostraram poucas variações. Foram definidos dois períodos sazonais, com base na precipitação média mensal que foi acompanhado pelo recrutamento de larvas que mostrou ser mais intenso no período de estiagem (verão). Esta sazonalidade do recrutamento parece estar mais relacionada com a transparência da água que mostrou ser o fator abiótico mais importante, pois a elevada turbidez da água nos meses de chuva que foi potencializado pelas atividades de dragagem do porto interno no mesmo período, elevando a quantidade de material em suspensão, o que impediu o recrutamento das larvas. Com relação aos tipos de tratamento empregados nas placas, a tinta anti-fouling mostrou-se eficiente e de ação duradoura sobre os organismos incrustantes locais. O zarcão comum não ofereceu nenhuma proteção contra o desenvolvimento do fouling
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Hodson, SL. "Biofouling of salmon-cage netting : fouling quantification, removal and prevention". Thesis, 1998. https://eprints.utas.edu.au/20565/7/Hodson_whole%20thesis_ex_pub_mat.pdf.
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The quantification, removal and prevention of biofouling on salmon-cage netting were investigated in Tasmania, Australia. Trials were aimed at identifying environmentally-acceptable alternatives to traditional toxic antifoulants, and focussed on three areas, viz. (1) underwater cleaning, (2) a "foul-release" silicone coating, and (3) extruded polymers incorporating naturally-occurring compounds or a commercial shortlived biocide. Each of these strategies was found to be applicable and effective for the prevention and/or reduction of fouling on netting. Trials identified future directions to improve antifouling efficacy, and potential problems such as resistant organisms. The development of a quantification technique and the description of fouling in each trial also provided information on the composition and variability within fouling communities on netting.
Image analysis of close-up underwater photographs of net fouling was used to quantify fouling removal and regrowth in terms of mesh occlusion. This enabled large numbers of non-destructive samples to be taken and analysed quickly, which compensated for the high degree of natural variability in the fouling communities. It also provided a permanent record of the fouling, allowed dominant species to be identified and counted, and permitted multiple sampling of the same area.
Underwater cleaning of netting was found to be highly effective when there was good contact between the brushes and netting, and prevented significant fouling development over a 10 week period. However, the design of the trialed prototype cleaner and the displacement of netting away from the cleaner, reduced the severity of scrubbing, limiting fouling removal. This effectiveness was further compromised because residual structures of fouling organisms and the large quantity of debris led to rapid regrowth and recolonisation. The research identified areas for design improvement, the problems associated with residual fouling and regrowth, and the requirements for effective in situ net cleaning. The results demonstrate many difficulties that may limit the efficacy of in situ cleaning, but suggest that this technology can significantly extend the immersion time of nets during seasons of peak fouling.
The application of a commercial silicone coating (Viridian 2000, International Paints) to netting proved effective for increasing the ease of cleaning and reducing the total mass of attached fouling. The silicone coating was particularly effective at preventing invertebrate fouling, and an absence solitary ascidians significantly reduced total fouling biomass. However, the total algal biomass on the silicone was comparable to uncoated netting, and some algal species were more abundant on the silicone (Ulva rigida and Polysiphonia brodiaei). This latter effect was considered to represent effects of surface colour, reduced competition, and differences in attachment strength. The application of current silicone coatings to fish-cage netting was considered to be problematic because their poor abrasion resistance and tear strength make them unsuitable for shore-based cleaning and handling procedures. Nonetheless, the flexibility of silicone coatings and the effective reduction of fouling adhesion make them ideal for fish cages that will be cleaned in situ, and may provide an effective non-toxic solution to reduce the cost of fouling removal.
Extruded polymers (plastics) incorporating either naturally-occurring compounds or commercially-available biocides were found to prevent macrofouling development for up to 209 days in field trials. The efficacy of polymers that incorporate either an algal extract (Delisea pulchra or Laurencia rigida), an analog to a halogenated furanone (that occurs in D. pulchra), or one of four commercial biocides (Busan 11-M1, Irgarol 1051, Nopcocide N-96 and Sea-nine 211) was investigated. Fouling prevention was shown to be a function of the polymer type and initial loading of the antifouling compound. Sea-nine 211 and the natural product analog were highly effective when incorporated into ethylenevinyl acetate copolymers, and therefore this type of polymer may be suitable for mixtures of these antifouling compounds. A high-density polyethylene (Shell, HET 6100) and a copolymer of ethylene and acrylic acid (BASF, Lucalen® A) were also effective for Seanine 211. The current success with polymers that incorporate antifouling compounds, and the many options for increasing their efficacy, are encouraging for the development of netting which resists fouling.
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Egan, Suhelen. "Production and regulation of fouling inhibitory compounds by the marine bacterium Pseudoalteromonas tunicata /". 2001. http://www.library.unsw.edu.au/~thesis/adt-NUN/public/adt-NUN20010925.141640/index.html.
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Chen, Ping-Hung y 陳秉弘. "Studies on fouling organisms in the marine cage culture". Thesis, 1999. http://ndltd.ncl.edu.tw/handle/23651981182206032996.
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碩士國立中山大學
海洋資源學系
87
Cage culture along coastal water is a recently development of aquaculture. A net can be encrusted with fouling organisms. The fouling organisms increase resistance to water flow. The additional weight of fouling on cage bags makes net changing difficult. Biofouling will cause net bag deformation by hindering water flow. The composition and succession of epibionts on the cage and their potential consequences have been studied. In order to understand the biofouling on the cage net, we conducted a survey on the fouling conditions on the cage net along both the coasts of Liuchiuyu and Zukeng of Taiwan. For fieldwork of cage net, the fouling communities in summer and autumn contained more taxon than in spring and winter (maximum difference was 9 taxa.). The parallel-current face of the cage net is more than that on the counter-current face (max. diff. was 12 taxa.), and more at Liuchiuyu than Zukeng (diff. was 6 taxa.). For two orders, April and September, the experiment-net sets of net with mesh size of 1.5cm2, were deployed in the cage culture ground in Liuchiyu. The results showed that the number of species was greater for submersion in autumn than spring. This suggested a temperature difference for net settlement between these two season. After observing for three months we counted more than 30 species from all experiment-nets. The similarity of fouling organisms and biomass of experiment-nets suggested stabilization. The predominant forms were compound algae and burnacle. The sum weight of both can be 50% or over in total weight. Fouling was mostly composed of algae at 1.5 and 3 m depth. An increase at depth facilitated barnacle settlement on nets. However, during September, the experiment-net sets of net with mesh size of 1.5cm2 and 3 cm2, were deployed in the cage culture ground in Liuchiyu. The results showed that the diversity of fouling organisms was more on the smallest mesh size. The most abundant species on the largest mesh was barnacle. The net mesh congestion could be evaluated from the area of mesh and diameter of the thread of net. Statistical analyses using the linear regression gave the biomass between these two evaluation. The correlation is positive for mesh area and wet weight. The correlation of thread diameter and wet weight is negative. The best relation is between thread diameter and wet weight (coefficient of determination is 0.88). In the future, when fouling necessitates appropriate cage management, we suggest the diameter of thread be an important consideration.
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Perkins, Kathryn Jennifer. "Taxonomy, ecophysiology and mitigation of fouling diatoms in a hydro electric canal at Tarraleah (Tasmania)". Thesis, 2010. https://eprints.utas.edu.au/21185/1/whole_PerkinsKathrynJennifer2010_thesis.pdf.
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Negaresh, Ebrahim Chemical Sciences & Engineering Faculty of Engineering UNSW. "Particle and macromolecular fouling in submerged membrane". 2007. http://handle.unsw.edu.au/1959.4/40743.
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Particles and macromolecular components, including biopolymers (protein and carbohydrate), are viewed as the main foulants in the complex feed submerged membrane filtration systems such as membrane bioreactor (MBR). This work focused on two aspects of fouling in complex fluids: 1- Assessing fouling propensity and mechanisms for various model solutions. 2- Using of two specific solutions modelling biomass found in MBR for a better understanding of the fouling mechanisms in submerged MBR processes. Filtrations were carried out with 0.22 ??m PVDF hollow fibre membrane. Alginate was used as a model for polysaccharide, bovine serum albumin (BSA) as a model for protein, (un)washed yeast and bentonite were representing suspended solid contents. According to the data obtained during this study the fouling propensity of each model solution was classified as follow in a decreasing order: Alginate > unwashed yeast > washed yeast > BSA > bentonite for one-component solutions; and Alginate-washed yeast > Alginate-BSA > Alginate-bentonite > Alginate-unwashed yeast for two-component solutions. Introducing the alginate increased the reversible fouling (except BSA). Passive adsorption had a significant effect on fouling of alginate even before the beginning of the filtration. Washed yeast and a mixture of washed yeast + BSA were then used as model solutions to simulate the activated sludge found in MBR. The concentration of washed yeast and BSA used in this study were calculated in order for the characterisations of the two model solution to match (in terms of biopolymer contents) those of MBR biomasses reported in the literature. By rinsing, backwashing and chemical cleaning of the membrane, three fouling layers of upper, intermediate and lower were defined respectively. Results obtained from the analysis of the biopolymers found in the cleaning solutions allow a better understanding of the fouling mechanisms occurring for the two model solutions used in this study: for washed yeast, the lower layer and for washed yeast + BSA , the upper and intermediate layers were found to have relatively high biopolymeric composition. This was explained by higher concentration of solids on the membrane surface and by higher biopolymer interactions when washed yeast was mixed with BSA.
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Mouland, Derek J. "A study of algal biofouling on pearl nets in Charles Arm, Notre Dame Bay, Newfoundland /". 2003.
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