Create textured surfaces (≤1 mm) on subtidal artificial structures

How is the evidence assessed?
  • Effectiveness
    not assessed
  • Certainty
    not assessed
  • Harms
    not assessed

Study locations

Key messages

  • Three studies examined the effects of creating textured surfaces on subtidal artificial structures on the biodiversity of those structures. Two studies were on open coastlines in Italy and Israel, and one was in an estuary in eastern USA.

COMMUNITY RESPONSE (3 STUDIES)

  • Overall community composition (3 studies): Two of three replicated, controlled studies (including two randomized studies) in Italy, Israel and the USA found that creating textured surfaces on subtidal artificial structures, along with using environmentally-sensitive material in one, altered the combined macroalgae and invertebrate community composition on structure surfaces, while one found no effect. One of the studies also reported that textured surfaces with environementally-sensitive material supported mobile and non-mobile invertebrate species that were absent from fibreglass surfaces without texture.
  • Overall richness/diversity (2 studies): One of two replicated, controlled studies (including one randomized study) in Italy and the USA found that creating textured surfaces on subtidal artificial structures did not increase the combined macroalgae and non-mobile invertebrate species richness on structure surfaces. One study found that creating textured surfaces, along with using environmentally-sensitive material, did.

POPULATION RESPONSE (3 STUDIES)

  • Overall abundance (3 studies): Two of three replicated, controlled studies (including two randomized studies) in Italy, Israel and the USA found that creating textured surfaces on subtidal artificial structures did not increase the combined macroalgae and non-mobile invertebrate live cover on structure surfaces. One study found that creating textured surfaces, along with using environmentally-sensitive material, did increase the cover and biomass.
  • Algal abundance (1 study): One replicated, randomized, controlled study in Italy found that creating textured surfaces on subtidal artificial structures had mixed effects on the macroalgal abundance on structure surfaces, depending on the species group and site.
  • Invertebrate abundance (1 study): One replicated, randomized, controlled study in Italy found that creating textured surfaces on subtidal artificial structures had mixed effects on the non-mobile invertebrate abundance on structure surfaces, depending on the site.

BEHAVIOUR (0 STUDIES)

About key messages

Key messages provide a descriptive index to studies we have found that test this intervention.

Studies are not directly comparable or of equal value. When making decisions based on this evidence, you should consider factors such as study size, study design, reported metrics and relevance of the study to your situation, rather than simply counting the number of studies that support a particular interpretation.

Supporting evidence from individual studies

  1. A replicated, randomized, controlled study in 2005 on three subtidal rocky reefs on open coastlines in the Adriatic Sea and the Ionian Sea, Italy (Guarnieri et al. 2009) found that settlement plates with and without textured surfaces supported similar macroalgae and non-mobile invertebrate species richness, live cover and community composition, while abundances varied depending on the species group and site. After nine months, there was no clear difference in the macroalgae and non-mobile invertebrate community composition, species richness or live cover on plates with and without textured surfaces (data reported as statistical model results). Non-mobile invertebrates were more abundant on plates with texture (<1–6% cover) than without (<1–2%) but the difference was only significant at one of six sites. Macroalgal abundances varied by species group and site (see paper for results). Limestone, sandstone, granite and concrete settlement plates (150 × 100 mm) were made with and without textured surfaces. Five of each material-texture combination were randomly arranged, horizontally at 5 m depth in each of two sites on each of three limestone rocky reefs in February 2005. Macroalgae and non-mobile invertebrates on plates were counted in the laboratory over nine months.

    Study and other actions tested
  2. A replicated, randomized, controlled study (year not reported) on open coastlines in the Mediterranean Sea and the Gulf of Aqaba, Israel (Perkol-Finkel & Sella 2014) found that upward-facing settlement plates with textured surfaces supported similar macroalgae and non-mobile invertebrate abundance but different community composition to downward-facing surfaces without texture. After 12 months, macroalgae and non-mobile invertebrate live cover was similar on upward-facing settlement plate surfaces with texture (81–100%) and downward-facing surfaces without (80–100%), but the community composition differed (data reported as statistical model results). Concrete settlement plates (150 × 150 mm) were moulded with textured surfaces on one side and flat on the other, using a formliner. Plates were either standard-concrete or one of five patented ECOncreteTM materials. Ten of each material were randomly arranged horizontally with textured surfaces facing upwards on frames at 6 m depth in the Mediterranean Sea and at 10 m in the Gulf of Aqaba (month/year not reported). Macroalgae and non-mobile invertebrates on plates were counted and biomass (dry weight) was recorded in the laboratory over 12 months.

    Study and other actions tested
  3. A replicated, controlled study in 2013–2014 on 24 jetty pilings in the Hudson River estuary, USA (Perkol-Finkel & Sella 2016) found that creating textured surfaces on the pilings, along with using environmentally-sensitive material, increased the macroalgae and invertebrate species richness, cover and biomass and altered the community composition on piling surfaces. After 14 months, pilings with textured surfaces and environmentally-sensitive material supported 18 macroalgae and invertebrate species with 90–100% cover, while fibreglass pilings without texture supported nine species with 40–85% cover (data not statistically tested). Biomass was higher on pilings with textured surfaces (0.07 g/cm2) than without (0.02 g/cm2) and the community composition differed (data reported as statistical model results). Over 14 months, six species (4 non-mobile invertebrates, 2 mobile invertebrates) recorded on pilings with texture were absent from those without. It is not clear whether these effects were the direct result of creating textured surfaces or using environmentally-sensitive material. Textured surfaces were created on concrete jetty piling encasements using a formliner during maintenance works. Nine textured encasements made from patented ECOncreteTM material and three untextured fibreglass encasements were attached around pilings in each of two sites along a jetty in June 2013 (depth not reported). Macroalgae and invertebrates were counted on and around pilings and biomass was measured (dry weight) in the laboratory over 14 months.

    Study and other actions tested
Please cite as:

Evans, A.J., Moore, P.J., Firth, L.B., Smith, R.K., and Sutherland, W.J. (2021) Enhancing the Biodiversity of Marine Artificial Structures: Global Evidence for the Effects of Interventions. Conservation Evidence Series Synopses. University of Cambridge, Cambridge, UK.

Where has this evidence come from?

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Biodiversity of Marine Artificial Structures

This Action forms part of the Action Synopsis:

Biodiversity of Marine Artificial Structures
Biodiversity of Marine Artificial Structures

Biodiversity of Marine Artificial Structures - Published 2021

Enhancing biodiversity of marine artificial structures synopsis

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