Study

Succession of seawall algal communities on artificial substrates

  • Published source details Loke L.H.L., Liao L.M., Bouma T.J. & Todd P.A. (2016) Succession of seawall algal communities on artificial substrates. Raffles Bulletin of Zoology, 32, 1-10.

Actions

This study is summarised as evidence for the following.

Action Category

Create grooves and small protrusions, ridges or ledges (1–50 mm) on intertidal artificial structures

Action Link
Biodiversity of Marine Artificial Structures

Create pit habitats (1–50 mm) on intertidal artificial structures

Action Link
Biodiversity of Marine Artificial Structures
  1. Create grooves and small protrusions, ridges or ledges (1–50 mm) on intertidal artificial structures

    A replicated, randomized, controlled study in 2011–2012 on two intertidal seawalls on island coastlines in the Singapore Strait, Singapore (Loke et al. 2016; same experimental set-up as Loke et al. 2017) reported that concrete settlement plates with groove habitats and small ridges, along with pits, supported higher macroalgal species richness but similar abundances compared with granite plates without added habitats. After 12 months, settlement plates with grooves, ridges and pits supported a total of five macroalgal species groups, while plates without supported three (data not statistically tested). Abundances of three species groups were statistically similar on plates with added habitats (18–41% cover) and without (5–61%) in five of six comparisons, while one group was more abundant on plates with added habitats (22–27 vs 5%) at one site. Abundances were similar on plates with variable (1–34%) and regular (3–41%) habitats. It is not clear whether these effects were the direct result of creating grooves, ridges or pits. Settlement plates (400 × 400 mm) were moulded with groove habitats and small ridges, with pits, and with neither. Plates with grooves, ridges and pits were concrete with four-to-five concentric circular grooves and ridges/plate or 36 pits/plate. Grooves, ridges and pits had either regular (32 mm width, depth/height and spacing) or variable (8–56 mm) arrangement. Plates without grooves, ridges or pits were granite fragments set in cement. Granite may be considered an environmentally-sensitive material compared with concrete (see “Use environmentally-sensitive material on intertidal artificial structures”). Five of each design were randomly arranged at lowshore on each of two granite boulder seawalls in July 2011. Macroalgae on plates were counted from photographs after 12 months.

    (Summarised by: Ally Evans)

  2. Create pit habitats (1–50 mm) on intertidal artificial structures

    A replicated, randomized, controlled study in 2011–2012 on two intertidal seawalls on island coastlines in the Singapore Strait, Singapore (Loke et al. 2016; same experimental set-up as Loke et al. 2017) reported that concrete settlement plates with pit habitats, along with grooves and small ridges, supported higher macroalgal species richness but similar abundances compared with granite plates without added habitats. After 12 months, settlement plates with pits, grooves and ridges supported a total of five macroalgal species groups, while plates without supported three (data not statistically tested). Abundances of three species groups were statistically similar on plates with pits, grooves and ridges (18–41% cover) and without (5–61%) in five of six comparisons, while one group was more abundant on plates with pits, grooves and ridges (22–27 vs 5%) at one site. Abundances were similar on plates with variable (1–34%) and regular (3–41%) habitats. It is not clear whether these effects were the direct result of creating pits, grooves or ridges. Settlement plates (400 × 400 mm) were moulded with pit habitats, with grooves and small ridges, and with neither. Plates with pits, grooves and ridges were concrete with 36 square pits/plate or four-to-five grooves and ridges/plate. Pits, grooves and ridges were either regular (32 mm width, depth/height and spacing) or variable (8–56 mm). Plates without pits, grooves or ridges were granite fragments set in cement. Granite may be considered an environmentally-sensitive material compared with concrete (see “Use environmentally-sensitive material on intertidal artificial structures”). Five of each design were randomly arranged at lowshore on each of two granite boulder seawalls in July 2011. Macroalgae on plates were counted from photographs after 12 months.

    (Summarised by: Ally Evans)

Output references
What Works 2021 cover

What Works in Conservation

What Works in Conservation provides expert assessments of the effectiveness of actions, based on summarised evidence, in synopses. Subjects covered so far include amphibians, birds, mammals, forests, peatland and control of freshwater invasive species. More are in progress.

More about What Works in Conservation

Download free PDF or purchase
The Conservation Evidence Journal

The Conservation Evidence Journal

An online, free to publish in, open-access journal publishing results from research and projects that test the effectiveness of conservation actions.

Read the latest volume: Volume 18

Go to the CE Journal

Discover more on our blog

Our blog contains the latest news and updates from the Conservation Evidence team, the Conservation Evidence Journal, and our global partners in evidence-based conservation.


Who uses Conservation Evidence?

Meet some of the evidence champions

Endangered Landscape Programme Red List Champion - Arc Kent Wildlife Trust The Rufford Foundation Save the Frogs - Ghana Bern wood Supporting Conservation Leaders National Biodiversity Network Sustainability Dashboard Frog Life The international journey of Conservation - Oryx British trust for ornithology Cool Farm Alliance UNEP AWFA Butterfly Conservation People trust for endangered species Vincet Wildlife Trust