Effects of non-biocidal coating technologies on colonisation by ectocarpoid algae

Algae are well-recognised for their fouling impact on immersed surfaces. During this thesis, the relationships between surface and bulk properties of coatings and the adhesion preferences of a new test species, Ectocarpus crouaniorum, a filamentous brown alga and a significant member of fouling communities, were explored. A novel laboratory-based adhesion bioassay for E. crouaniorum using small filamentous fragments as inocula was developed. The bioassay was used to screen sets of experimental coatings at an appropriate scale in well-replicated and controlled experiments. Sets of coatings with varying wettability, surface charge or modulus were produced, characterised and assayed. The attachment and adhesion preferences of E. crouaniorum were influenced by the surface and bulk properties. These preferences were compared with those of U. linza. No linear correlation was observed between the adhesion strength of E. crouaniorum and wettability in contrast to the linear relationship observed testing U. linza; increase of modulus decreased or increased the adhesion strength of E. crouaniorum and U. linza, respectively. However, both species had lower adhesion on uncharged xerogel coatings. The performance of test coatings was also assessed in field assays and the results showed that these data were not always similar to the laboratory assay