Effect of background colour on growth and adhesion strength of Ulva sporelings

Abstract

This study examined the effects of a range of black, grey and white substrata on the growth and attachment strength of Ulva sporelings on glass and polydimethylsiloxane (Silastic®-T2) surfaces. The rate of development of sporelings was strongly influenced by the colour of the substratum on which they grew. On black backgrounds, sporelings grew slowly and germination was delayed. Laboratory screening methods for antifouling and fouling-release coatings that rely on the growth of Ulva sporelings can be compromised if samples are of different colours. Hydrodynamic removal of sporelings from coatings may also be affected by substratum colour, since smaller plants generate lower hydrodynamic forces making them more difficult to remove.

Keywords:

• adhesion
• algae
• antifouling paint
• fouling
• fouling-release
• light
• Ulva

Acknowledgements

This research was supported by the Office of Naval Research grant N00014-05-1-0134. The PDMS surfaces (glass slides coated with Silastic®-T2) were provided by Professor AB Brennan of the University of Florida. We thank Professor RC Zimmerman (Old Dominion University) for information on emission spectra of background coatings.