Colonisation of artificial structures by primary producers: competition and photosynthetic behaviour

Abstract

Colonisation of artificial structures by primary producers is an important determinant for eco-engineering projects. In this context, interactions between the colonisation by microphytobenthic biofilm and macroalgae were explored on 48 samples of marine infrastructures (MI) immersed for one year in the English Channel. Marine infrastructures samples with smooth and rough surface were compared to evaluate the influence of surface micro-scale rugosity. Microphytobenthos biomass (MPB), macroalgal diversity and photosynthetic parameters of both were assessed during colonisation. No significant differences were found as a function of the surface rugosity of MI samples, which was unexpected, but can be explained by biogenic rugosity provided by barnacles. Marine infrastructures were largely colonised by a red encrusting alga, Phymatolithon purpureum, which showed poor photosynthetic capacity compared to the microphytobenthos present next to it. Colonisation by monospecific encrusting algae tended to reduce the primary productivity of hard substrate.

Keywords:

• Benthic communities
• photosynthesis
• microphytobenthos
• encrusting algae
• marine infrastructures

Acknowledgements

The authors wish to thank the co-financiers and all project partners for their support. The project is cofounded by the European Union, Normandy Region within the FEDER/FSE 2014-2020 – Manche 2021 programme. The authors thank Normandy Region for funding IMAGING-PAM (CPER Manche 2021).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

These results were obtained in the collaborative project Interreg Va MARINEFF, selected under the European Cross-border Programme INTERREG FMA, and co-funded by the ERDF.