The effect of surface colour on the formation of marine micro and macrofouling communities

Abstract

The effect of substratum colour on the formation of micro- and macro fouling communities was investigated. Acrylic tiles, painted either black or white were covered with transparent sheets in order to ensure similar surface properties. All substrata were exposed to biofouling at 1 m depth for 40 d in the Marina Bandar al Rowdha (Muscat, Sea of Oman). Studies were conducted in 2010 over a time course of 5, 10 and 20 d, and in 2012 samples were collected at 7, 14 and 21 d. The densities of bacteria on the black and white substrata were similar with the exception of day 10, when the black substrata had a higher abundance than white ones. Pyrosequencing via 454 of 16S rRNA genes of bacteria from white and black substrata revealed that Alphaproteobacteria and Firmicutes were the dominant groups. SIMPER analysis demonstrated that bacterial phylotypes (uncultured Gammaproteobacteria, Actibacter, Gaetbulicola, Thalassobius and Silicibacter) and the diatoms (Navicula directa, Navicula sp. and Nitzschia sp.) contributed to the dissimilarities between communities developed on white and black substrata. At day 20, the highest amount of chlorophyll a was recorded in biofilms developed on black substrata. SIMPER analysis showed that Folliculina sp., Ulva sp. and Balanus amphitrite were the major macro fouling species that contributed to the dissimilarities between the communities formed on white and black substrata. Higher densities of these species were observed on black tiles. The results emphasise the effect of substratum colour on the formation of micro and macro fouling communities; substratum colour should to be taken into account in future studies.

Keywords:

• colour
• biofouling community
• bacteria
• diatoms
• biofilms
• pyrosequencing

Acknowledgements

The authors acknowledge Dr Andrew N. Ostrovsky (Vienna University) for the identification of bryozoan species and Ms Annika Vaksmaa (Roskilde University) for her help with the experiments and data analysis. The authors thank Mr Khalid Al-Hashmi for his help in the identification of diatoms. 454 pyrosequencing was funded by King Abdullah University of Science and Technology (KAUST), Saudi Arabia. The authors wish to thank Dr Till Bayer for raw data collection and the Bioscience Core Lab at KAUST for preparation and sequencing of 454 libraries. The work of SD was supported by a Sultan Qaboos University internal grant IG/AGR/FISH/12/01 and by a HM Sultan Qaboos Research Trust Fund SR/AGR/FISH/10/01. SD acknowledges the help of Professor R. Coutinho (IEAPM, Arraial do Cabo, Brazil) and the programme science without frontiers (CNPq). RA would like to thank the Hanse-Wissenschaftskolleg (HWK), Institute for Advanced Study, Germany for their support.