Influence of concrete properties on the initial biological colonisation of marine artificial structures

  • Published source details Natanzi A.S., Thompson B.J., Brooks P.R., Crowe T.P. & McNally C. (2021) Influence of concrete properties on the initial biological colonisation of marine artificial structures. Ecological Engineering, 159, 106104.


This study is summarised as evidence for the following.

Action Category

Use environmentally-sensitive material on intertidal artificial structures

Action Link
Biodiversity of Marine Artificial Structures
  1. Use environmentally-sensitive material on intertidal artificial structures

    A replicated, randomized, controlled study in 2018 on an intertidal breakwater on open coastline in the Irish Sea, Ireland (Natanzi et al. 2021) found that replacing standard Portland-cement with Ground Granulated Blast-Furnace Slag (GGBS), limestone-aggregate with granite-aggregate, and omitting plasticiser in concrete settlement plates had mixed effects on microalgal and barnacle (Cirripedia) abundances, depending on the material combination, wave-exposure and species group. After one month, on the wave-sheltered side of the breakwater, microalgal biomass was higher on plates with GGBS-cement (0.14–2.48 μg/cm2) than standard-cement (0.03–0.74 μg/cm2). Barnacle abundance varied depending on the aggregate and presence of plasticiser (GGBS-cement: 316–2,961 individuals/plate; standard-cement: 603–1,869/plate). There was no significant difference in microalgal or barnacle abundance between plates with granite-aggregate (microalgae: 0.03–1.66 μg/cm2; barnacles: 316–2,961/plate) and limestone-aggregate (microalgae: 0.06–2.48 μg/cm2; barnacles: 973–2,263/plate), or between plates without and with plasticiser (microalgae: 0.06–2.48 vs 0.03–1.66 μg/cm2; barnacles: 316–2,263 vs 603–2,961/plate). On the exposed side of the breakwater, results varied depending on the cement-aggregate-plasticiser combination and species group. Concrete settlement plates (200 × 200 mm) were moulded with different cement (GGBS, standard Portland-cement), aggregates (granite, limestone) and additives (no plasticiser, plasticiser). Six plates of each binder-aggregate-additive combination were randomly arranged vertically at mid-lowshore on the wave-sheltered side of a boulder breakwater in April 2018. Two plates of each were attached on the wave-exposed side. Microalgal biomass on plates was measured using a fluorometer and barnacles were counted from photographs after 1 month.

    (Summarised by: Ally Evans)

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