Collected Evidence: Collected Evidence: Create small adjoining cavities or ‘swimthrough’ habitats (≤100 mm) on subtidal artificial structures Four studies examined the effects of creating small adjoining cavities or ‘swimthrough’ habitats on subtidal artificial structures on the biodiversity of those structures. Two studies were in marinas in France and Morocco, while one was in each of a lagoon in Mayotte and a port in France. COMMUNITY RESPONSE (1 STUDY) Fish community composition (1 study): One replicated, paired sites, controlled study in France found that creating small swimthrough habitats on subtidal artificial structures had mixed effects on the juvenile fish community composition on and around structure surfaces, depending on the site and survey month. Swimthrough habitats supported six species that were absent from structure surfaces without swimthroughs. Fish richness/diversity (1 study): One replicated, paired sites, controlled study in France found that creating small swimthrough habitats on subtidal artificial structures had mixed effects on juvenile fish species richness on and around structure surfaces, depending on the site. POPULATION RESPONSE (2 STUDIES) Fish abundance (2 studies): Two replicated, paired sites, controlled studies in France found that creating small swimthrough habitats on subtidal artificial structures had mixed effects on juvenile fish abundances on and around structure surfaces, depending on the species, site, survey month and/or juvenile development stage. BEHAVIOUR (3 STUDIES) Use (3 studies): One replicated, paired sites, controlled study in France found that creating small swimthrough habitats on subtidal artificial structures had mixed effects on juvenile seabream habitat use on and around structure surfaces, depending on the species and juvenile development stage. Two studies (including one replicated study) in Mayotte and Morocco reported that small swimthrough habitats, along with large swimthroughs and environmentally-sensitive material in one, were used by juvenile spiny lobsters, sea firs, adult fish and/or juvenile fish. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3436https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3436Fri, 13 Aug 2021 12:15:34 +0100Collected Evidence: Collected Evidence: Reduce the slope of subtidal artificial structures We found no studies that evaluated the effects of reducing the slope of subtidal artificial structures on the biodiversity of those structures. This means we did not find any studies that directly evaluated this intervention during our literature searches. Therefore, we have no evidence to indicate whether or not the intervention has any desirable or harmful effects.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3442https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3442Fri, 20 Aug 2021 10:09:55 +0100Collected Evidence: Collected Evidence: Create small ridges or ledges (1–50 mm) on subtidal artificial structures We found no studies that evaluated the effects of creating small ridges or ledges on subtidal artificial structures on the biodiversity of those structures. This means we did not find any studies that directly evaluated this intervention during our literature searches. Therefore, we have no evidence to indicate whether or not the intervention has any desirable or harmful effects.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3444https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3444Fri, 20 Aug 2021 11:00:57 +0100Collected Evidence: Collected Evidence: Create textured surfaces (≤1 mm) on subtidal artificial structures 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)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3449https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3449Tue, 31 Aug 2021 15:40:02 +0100Collected Evidence: Collected Evidence: Create short flexible habitats (1–50 mm) on subtidal artificial structures Three studies examined the effects of creating short flexible habitats on subtidal artificial structures on the biodiversity of those structures. Two studies were in an estuary in southeast Australia and one was in marinas in northwest France. COMMUNITY RESPONSE (2 STUDIES) Invertebrate community composition (2 studies): Two replicated, randomized, controlled studies (including one paired sites study) in Australia and France found that creating short flexible habitats on subtidal artificial structures had mixed effects on the mobile and/or non-mobile invertebrate community composition, depending on the density or length of flexible habitats and/or the site. One of the studies found it altered the non-mobile invertebrate community composition. Invertebrate richness/diversity (1 study): One replicated, randomized, paired sites, controlled study in France found that creating short flexible habitats on subtidal artificial structures did not increase the mobile or non-mobile invertebrate species richness on structure surfaces. POPULATION RESPONSE (3 STUDIES) Invertebrate abundance (3 studies): Three randomized, controlled studies (including two replicated and one paired sites study) in Australia and France found that creating short flexible habitats on subtidal artificial structures had mixed effects on the mobile and/or non-mobile invertebrate abundance on and around structure surfaces, depending on the survey week, species group, flexible habitat length, or site. One of the studies found no effect on mobile invertebrate abundance. Fish abundance (1 study): One randomized, controlled study in Australia found that creating short flexible habitats on subtidal artificial structures had mixed effects on the seahorse abundance on and around structures, depending on the survey week. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3450https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3450Wed, 08 Sep 2021 15:19:19 +0100Collected Evidence: Collected Evidence: Create small protrusions (1–50 mm) on subtidal artificial structures One study examined the effects of creating small protrusions on subtidal artificial structures on the biodiversity of those structures. The study was on an open coastline in Japan. COMMUNITY RESPONSE (0 STUDIES)   POPULATION RESPONSE (1 STUDY) Algal abundance (1 study): One controlled study in Japan reported that creating small protrusions on a subtidal artificial structure had mixed effects on the macroalgal abundance on structure surfaces, depending on the species. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3453https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3453Fri, 10 Sep 2021 10:06:48 +0100Collected Evidence: Collected Evidence: Manage or restrict harvesting of species on subtidal artificial structures Three studies examined the effects of managing or restricting harvesting of species on subtidal artificial structures on the biodiversity of those structures or on human behaviour likely to influence the biodiversity of those structures. The studies were on open coastlines in Italy. COMMUNITY RESPONSE (1 STUDY) Fish community composition (1 study): One site comparison study in Italy found different fish community composition around subtidal artificial structures with and without harvesting restrictions. The structure with harvesting restrictions supported species that were absent from unrestricted structures. Fish richness/diversity (1 study): One site comparison study in Italy found higher fish species richness around a subtidal artificial structure with harvesting restrictions compared with unrestricted structures. POPULATION RESPONSE (2 STUDIES) Invertebrate abundance (1 study): One site comparison study in Italy found similar sea urchin abundances around subtidal artificial structures with and without harvesting restrictions. Fish abundance (2 studies): One of two site comparison studies in Italy found similar total fish abundance around subtidal artificial structures with and without harvesting restrictions, but that abundances varied depending on the species and the survey date. One study found higher seabream abundances around the structure with harvesting restrictions. BEHAVIOUR (1 STUDY) Human behaviour change (1 study): One replicated, randomized study in Italy reported that legally restricting human access on subidal artificial structures did not prevent people from harvesting invertebrates and fishes on and around structures. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3457https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3457Mon, 13 Sep 2021 14:55:24 +0100Collected Evidence: Collected Evidence: Manage or restrict harvesting of species on intertidal artificial structures Two studies examined the effects of managing or restricting harvesting of species on intertidal artificial structures on the biodiversity of those structures or on human behaviour likely to influence the biodiversity of those structures. One study was on open coastlines in Italy, and one was in ports and on open coastlines in Gibraltar and southeast Spain. COMMUNITY RESPONSE (0 STUDIES)   POPULATION RESPONSE (1 STUDY) Invertebrate abundance (1 study): One replicated, site comparison study in Gibraltar and Spain reported that restricting human access on intertidal artificial structures did not increase the limpet abundance on structure surfaces. Invertebrate condition (1 study): One replicated, site comparison study in Gibraltar and Spain found that restricting human access on intertidal artificial structures resulted in larger limpets with more balanced sex ratios than unrestricted structures. BEHAVIOUR (1 STUDY) Human behaviour change (1 study): One replicated, randomized study in Italy reported that legally restricting human access on intertidal artificial structures did not prevent people from harvesting invertebrates and fishes on and around structures. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3458https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3458Mon, 13 Sep 2021 15:57:49 +0100Collected Evidence: Collected Evidence: Create short flexible habitats (1–50 mm) on intertidal artificial structures One study examined the effects of creating short flexible habitats on intertidal artificial structures on the biodiversity of those structures. The study was in an estuary in southeast Australia. COMMUNITY RESPONSE (1 STUDY) Overall community composition (1 study): One replicated, randomized, controlled study in Australia found that creating short flexible habitats on intertidal artificial structures altered the combined macroalgae and non-mobile invertebrate community composition on structure surfaces, and had mixed effects on the combined mobile invertebrate and fish community composition on and around structure surfaces during low tide, depending on the site. Invertebrate community composition (1 study): One replicated, randomized, controlled study in Australia found that creating short flexible habitats on intertidal artificial structures did not alter the mobile invertebrate community composition on and around structure surfaces during high tide. Fish community composition (1 study): One replicated, randomized, controlled study in Australia found that creating short flexible habitats on intertidal artificial structures did not alter the fish community composition on and around structure surfaces during high tide. Overall richness/diversity (1 study): One replicated, randomized, controlled study in Australia found that creating short flexible habitats on intertidal artificial structures decreased the combined macroalgae, invertebrate and fish species richness on and around structure surfaces during low tide. Invertebrate richness/diversity (1 study): One replicated, randomized, controlled study in Australia found that creating short flexible habitats on intertidal artificial structures had mixed effects on the mobile invertebrate species richness on and around structure surfaces during high tide, depending on the site. Fish richness/diversity (1 study): One replicated, randomized, controlled study in Australia found that creating short flexible habitats on intertidal artificial structures did not increase the fish species richness on and around structure surfaces during high tide. POPULATION RESPONSE (1 STUDY) Overall abundance (1 study): One replicated, randomized, controlled study in Australia found that creating short flexible habitats on intertidal artificial structures did not increase the combined mobile invertebrate and fish abundance on and around structure surfaces during low tide. Algal abundance (1 study): One replicated, randomized, controlled study in Australia found that creating short flexible habitats on intertidal 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 Australia found that creating short flexible habitats on intertidal artificial structures had mixed effects on the abundance of non-mobile invertebrates on structure surfaces, and of mobile invertebrates during high tide, depending on the species group and site. Fish abundance (1 study): One replicated, randomized, controlled study in Australia found that creating short flexible habitats on intertidal artificial structures did not increase the fish abundance on and around structure surfaces during high tide. BEHAVIOUR (1 STUDY) Fish behaviour change (1 study): One replicated, randomized, controlled study in Australia found that creating short flexible habitats on intertidal artificial structures did not increase the number of bites fishes took of structure surfaces.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3459https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3459Mon, 13 Sep 2021 16:23:43 +0100Collected Evidence: Collected Evidence: Reduce the slope of intertidal artificial structures Two studies examined the effects of reducing the slope of intertidal artificial structures on the biodiversity of those structures. The studies were in an estuary in southeast Australia. COMMUNITY RESPONSE (1 STUDY) Overall richness/diversity (1 study): One before-and-after study in Australia reported that reducing the slope of an intertidal artificial structure, along with creating rock pools, increased the combined macroalgae, invertebrate and fish species richness on the structure. POPULATION RESPONSE (1 STUDY) Algal abundance (1 study): One replicated, controlled study in Australia found that reducing the slope of an intertidal artificial structure did not increase the macroalgal abundance on structure surfaces. Invertebrate abundance (1 study): One replicated, controlled study in Australia found that reducing the slope of an intertidal artificial structure did not increase the oyster or mobile invertebrate abundance on structure surfaces. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3461https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3461Tue, 14 Sep 2021 12:39:58 +0100Collected Evidence: Collected Evidence: Create small protrusions (1–50 mm) on intertidal artificial structures Two studies examined the effects of creating small protrusions on intertidal artificial structures on the biodiversity of those structures. Both studies were on island coastlines in the Singapore Strait. COMMUNITY RESPONSE (2 STUDIES) Overall community composition (2 studies): One of two replicated, randomized, controlled studies in Singapore found that creating small protrusions on intertidal artificial structures did not alter the combined macroalgae and invertebrate community composition on structure surfaces. One study found that creating small protrusions, along with grooves, small ridges and pits, had mixed effects on the community composition, depending on the site and the size and arrangement of protrusions and other habitats. Overall richness/diversity (2 studies): Two replicated, randomized, controlled studies in Singapore found that creating small protrusions on intertidal artificial structures, along with grooves, small ridges and pits in one study, increased the combined macroalgae and invertebrate species richness on structure surfaces. One of the studies found that varying the size and arrangement of protrusions and other habitats had mixed effects on species richness, depending on the shore level. POPULATION RESPONSE (2 STUDIES) Overall abundance (2 studies): One of two replicated, randomized, controlled studies in Singapore found that creating small protrusions on intertidal artificial structures did not increase the combined macroalgae and invertebrate abundance on structure surfaces. One study found that creating small protrusions, along with grooves, small ridges and pits, had mixed effects on abundance, depending on the shore level, site, and the size and arrangement of protrusions and other habitats. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3462https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3462Tue, 14 Sep 2021 14:36:13 +0100Collected Evidence: Collected Evidence: Create small ridges or ledges (1–50 mm) on intertidal artificial structures Four studies examined the effects of creating small ridges or ledges on intertidal artificial structures on the biodiversity of those structures. Two studies were on island coastlines in the Singapore Strait and two were in estuaries in Hong Kong and southeast Australia. COMMUNITY RESPONSE (4 STUDIES) Overall community composition (2 studies): One of two replicated, randomized, controlled studies in Singapore found that creating small ridges on intertidal artificial structures did not alter the combined macroalgae and invertebrate community composition on structure surfaces. One study found that creating small ridges, along with grooves, small protrusions and pits, had mixed effects on the community composition, depending on the site, and the size and arrangement of ridges and other habitats. Overall richness/diversity (4 studies): One of two replicated, randomized, controlled studies in Singapore found that creating small ridges on intertidal artificial structures did not increase the combined macroalgae and invertebrate species richness on structure surfaces. One study found that creating small ridges, along with grooves, small protrusions and pits, did increase the species richness, and that varying the habitat size and arrangement had mixed effects, depending on the shore level. Two replicated studies (including one randomized, paired sites study) in Hong Kong and Australia found that small ridges or ledges supported lower species richness than grooves created in between them, but one of them found that species diversity on ridges compared with grooves varied depending on the ridge height. Invertebrate richness/diversity (1 study): One replicated study in Australia found that small ledges created on intertidal artificial structures supported lower mobile invertebrate species richness than grooves created in between them. Fish richness/diversity (1 study): One replicated study in Australia found that small ledges created on intertidal artificial structures supported similar fish species richness to grooves created in between them. POPULATION RESPONSE (3 STUDIES) Overall abundance (3 studies): One of two replicated, randomized, controlled studies in Singapore found that creating small ridges on intertidal artificial structures did not increase the combined macroalgae and invertebrate abundance on structure surfaces. One study found that creating small ridges, along with grooves, small protrusions and pits, had mixed effects on abundance, depending on the shore level, site, and the size and arrangement of ridges and other habitats. One replicated study in Australia found that small ledges supported similar abundance to grooves created in between them. Invertebrate abundance (1 study): One replicated study in Australia found that small ledges created on intertidal artificial structures supported lower mobile invertebrate and oyster abundances than grooves created in between them. Fish abundance (1 study): One replicated study in Australia found that small ledges created on intertidal artificial structures supported similar fish abundance to grooves created in between them. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3464https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3464Tue, 14 Sep 2021 16:00:03 +0100Collected Evidence: Collected Evidence: Create textured surfaces (≤1 mm) on intertidal artificial structures Four studies examined the effects of creating textured surfaces on intertidal artificial structures on the biodiversity of those structures. Two studies were on open coastlines in the UK and the Netherlands, one was in a port in the Netherlands, and one was on an open coastline and in estuaries in the UK. COMMUNITY RESPONSE (1 STUDY) Overall richness/diversity (1 study): One replicated, randomized, controlled study in the UK found that creating textured surfaces on intertidal artificial structures, along with using environmentally-sensitive material, had mixed effects on the combined macroalgae and invertebrate species richness on structure surfaces, depending on the type of texture created and the site. POPULATION RESPONSE (4 STUDIES) Algal abundance (2 studies): Two replicated, paired sites, controlled studies in the Netherlands reported that creating textured surfaces on intertidal artificial structures did not increase the macroalgal abundance on structure surfaces. Invertebrate abundance (4 studies): Two of four replicated, controlled studies (including two randomized and two paired sites studies) in the UK and the Netherlands reported that creating textured surfaces on intertidal artificial structures did not increase the invertebrate abundance on structure surfaces. One study found that creating textured surfaces, along with using environmentally-sensitive material, had mixed effects on barnacle and mobile invertebrate abundances, depending on the site. One found increased barnacle abundance, regardless of the type of texture created, but that different textures supported different abundances. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3466https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3466Wed, 15 Sep 2021 16:05:59 +0100Collected Evidence: Collected Evidence: Create small adjoining cavities or ‘swimthrough’ habitats (≤100 mm) on intertidal artificial structures Two studies examined the effects of creating small adjoining cavities or ‘swimthrough’ habitats on intertidal artificial structures on the biodiversity of those structures. One study was on an open coastline in the UK and in an estuary in the Netherlands and one was on an open coastline in South Africa. COMMUNITY RESPONSE (2 STUDIES) Invertebrate community composition (1 study): One replicated, controlled study in South Africa found that creating small swimthrough habitats on intertidal artificial structures did not alter the mobile invertebrate community composition on structure surfaces. Overall richness/diversity (1 study): One replicated study in the UK and the Netherlands found that varying the size and arrangement of small swimthrough habitats created on intertidal artificial structures did not increase the combined macroalgae and invertebrate species richness in and on the structures. Invertebrate richness/diversity (1 study): One replicated, controlled study in South Africa found that creating small swimthrough habitats on intertidal artificial structures did not increase the mobile invertebrate species richness or diversity on structure surfaces. POPULATION RESPONSE (2 STUDIES) Invertebrate abundance (2 studies): One replicated, controlled study in South Africa found that creating small swimthrough habitats on intertidal artificial structures increased the mobile invertebrate abundance on structure surfaces. One replicated study in the UK and the Netherlands found that varying the size and arrangement of small swimthrough habitats altered the invertebrate abundance in and on structures. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3468https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3468Thu, 16 Sep 2021 14:03:21 +0100Collected Evidence: Collected Evidence: Use environmentally-sensitive material on intertidal artificial structures Eight studies examined the effects of using environmentally-sensitive material on intertidal artificial structures on the biodiversity of those structures. Three studies were on open coastlines in the UK and Ireland, and one was in each of an estuary in southeast Australia, a marina in northern Israel, and a port in southeast Spain. One was on an open coastline and in estuaries in the UK, and one was on island coastlines in the Singapore Strait and in estuaries in the UK. COMMUNITY RESPONSE (6 STUDIES) Overall community composition (4 studies): Two of four replicated, controlled studies (including three randomized and one paired sites, before-and-after study) in Australia, the UK, Israel, and Singapore and the UK, found that using hemp-concrete in place of standard-concrete on intertidal artificial structures, or using ECOncreteTM, along with creating grooves, small ledges and holes, altered the combined macroalgae and invertebrate community composition on structure surfaces. One of the studies, along with one other, found that using shell-concrete or reduced-pH-concrete did not. One study found that using sandstone in place of basalt had mixed effects, depending on the site. Two of the studies reported that ECOncreteTM surfaces with added habitats or reduced-pH-concrete surfaces supported macroalgae, mobile invertebrate and/or non-mobile invertebrate species that were absent from standard-concrete structure surfaces. Algal community composition (1 study): One replicated, randomized, paired sites, controlled study in Spain found that using different materials (sandstone, limestone, slate, gabbro, concrete) on an intertidal artificial structure altered the diatom community composition on structure surfaces. Overall richness/diversity (4 studies): Two of four replicated, controlled studies (including three randomized and one paired sites, before-and-after study) in the UK, Israel, and Singapore and the UK found that using hemp-concrete, shell-concrete or reduced-pH-concrete in place of standard-concrete on intertidal artificial structures did not increase the combined macroalgae and invertebrate species richness on structure surfaces. One study found that using ECOncreteTM, along with creating grooves, small ledges and holes, did increase the species richness and diversity. One found that using limestone-cement, along with creating pits, grooves, small ridges and texture, had mixed effects depending on the site. Algal richness/diversity (1 study): One replicated, randomized, paired sites, controlled study in Spain found that using quarried rock in place of concrete on an intertidal artificial structure did not increase the diatom species richness or diversity on structure surfaces. Invertebrate richness/diversity (1 study): One replicated, randomized, controlled study in the UK found that using hemp-concrete in place of standard-concrete on intertidal artificial structures increased the mobile invertebrate species richness on structure surfaces, but using shell-concrete did not. POPULATION RESPONSE (7 STUDIES) Overall abundance (1 study): One replicated, randomized, controlled study in the UK found that using hemp-concrete or shell-concrete in place of standard-concrete on intertidal artificial structures increased the combined macroalgae and non-mobile invertebrate abundance on structure surfaces. Algal abundance (5 studies): Four of five replicated, controlled studies (including four randomized and one paired sites study) in Australia, Spain, Singapore, the UK and Ireland found that using sandstone in place of basalt, quarried rock in place of concrete, or altering the composition of concrete on intertidal artificial structures had mixed effects on the macroalgal or microalgal abundance on structure surfaces, depending on the species group, site, wave-exposure and/or the type of material tested. One study found no effect of reducing the pH of concrete on macroalgal abundance. Invertebrate abundance (4 studies): Two of four replicated, controlled studies (including three randomized studies) in Australia, the UK, Singapore and the UK and Ireland found that using sandstone in place of basalt or reducing the pH of concrete on intertidal artificial structures did not increase the abundance of tubeworms, oysters, limpets, barnacles and/or combined invertebrates on structure surfaces. Two studies found that using limestone-cement, along with creating pits, grooves, small ridges and texture, or altering the composition of concrete had mixed effects on the mobile invertebrate and/or barnacle abundance, depending on the site, wave-exposure and/or the type of material tested. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3469https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3469Thu, 16 Sep 2021 15:46:12 +0100Collected Evidence: Collected Evidence: Use environmentally-sensitive material on subtidal artificial structures Fourteen studies examined the effects of using environmentally-sensitive material on subtidal artificial structures on the biodiversity of those structures. Seven studies were on open coastlines in the United Arab Emirates, Italy, Israel, southeast Spain, and in France, the UK, Portugal and Spain. Three were in marinas in northern Israel and the UK, two were in estuaries in southeast Australia and eastern USA, one was in a lagoon in Mayotte, and one was in a port in Germany. COMMUNITY RESPONSE (11 STUDIES) Overall community composition (11 studies): Six of 11 replicated, controlled studies (including eight randomized, three paired sites and one before-and-after study) in Australia, the United Arab Emirates, Italy, Israel, the USA, the UK, Spain and Germany found that using shell-concrete or quarried rock in place of standard-concrete on subtidal artificial structures, or using ECOncreteTM in place of standard-concrete or fibreglass, along with creating texture, grooves, holes, pits and/or small ledges, altered the combined macroalgae and invertebrate community composition on structure surfaces. Three studies found that using quarried rock or blast-furnace-cement-concrete in place of standard-concrete did not alter the community composition, while one found mixed effects depending on the type of rock tested and the site. One found that using different cement mixes in concrete (including some with recycled cements) altered the community composition of native species, but not non-natives. Three of the studies also reported that ECOncreteTM surfaces with added habitats supported mobile invertebrate, non-mobile invertebrate and/or fish species that were absent from standard-concrete or fibreglass structure surfaces. Overall richness/diversity (7 studies): Three of seven replicated, controlled studies (including five randomized, two paired sites and one before-and-after study) in Italy, Israel, the USA, the UK and Spain found that using quarried rock, shell-concrete or recycled-cement-concrete in place of standard-concrete on subtidal artificial structures had mixed effects on the combined macroalgae and invertebrate species richness on structure surfaces, depending on the site, surface orientation or type of cement tested. One of the studies, along with one other, found that using shell-concrete or quarried rock did not increase the species diversity and/or richness, while one found that using recycled cement did not increase the non-native species richness. Three studies found that using ECOncreteTM, along with creating texture, grooves, holes, pits and/or small ledges, did increase the species diversity and/or richness on and around structures. Algal richness/diversity (1 study): One replicated, randomized, controlled study in the UK found that using recycled-cement-concrete in place of standard-concrete on subtidal artificial structures did not increase the diatom species richness on structure surfaces. POPULATION RESPONSE (11 STUDIES) Overall abundance (7 studies): Three of seven replicated studies (including six controlled, four randomized and one paired sites study) in the United Arab Emirates, Italy, Israel, the USA, the UK, Spain, and in France, the UK, Portugal and Spain found that using quarried rock or shell-concrete in place of standard-concrete on subtidal artificial structures did not increase the combined macroalgae and invertebrate abundance on structure surfaces. Two studies found mixed effects, depending on the type of quarried rock or concrete tested and/or the location. One found that using ECOncreteTM in place of fibreglass, along with creating textured surfaces, increased the live cover and biomass, while one found that different ECOncreteTM and standard-concrete mixes supported different cover and inorganic biomass but similar organic biomass. Algal abundance (6 studies): Four of six replicated, controlled studies (including four randomized and one paired sites study) in Australia, the United Arab Emirates, Italy, Israel and the UK found that using quarried rock or recycled-cement-concrete in place of standard-concrete on subtidal artificial structures did not increase the abundance of brown, turf or coralline macroalgae, canopy macroalgae recruits or diatoms on structure surfaces. Two studies found that using quarried rock or using ECOncreteTM, along with creating grooves, holes and pits, had mixed effects on macroalgal abundance, depending on the species group and/or site. One of the studies found that using quarried rock increased red and green macroalgal abundance. Invertebrate abundance (6 studies): Three of six replicated, controlled studies (including four randomized and one paired sites study) in Austalia, the United Arab Emirates, Italy, Israel and the UK found that using quarried rock in place of concrete on subtidal artificial structures, or using ECOncreteTM, along with creating grooves, holes and pits, had mixed effects on the abundance of non-mobile invertebrates, mobile invertebrates or coral recruits on structure surfaces, depending on the type of rock tested, the species group and/or the site. One of the studies, along with one other, found that using quarried rock did not increase the abundance of sponges, bryozoans, ascidians, mussels, barnacles, or Serpulid tubeworms, but in one it decreased Spirorbid tubeworm abundance. One study found that using shell-concrete increased bivalve abundance. One found that different ECOncreteTM and standard-concrete mixes supported different coral abundance. Fish abundance (1 study): One replicated, controlled study in Israel found that using ECOncreteTM in place of standard-concrete on subtidal artificial structures, along with creating grooves, holes and pits, had mixed effects on fish abundances, depending on the species group. BEHAVIOUR (1 STUDY) Use (1 study): One study in Mayotte reported that basalt rock surfaces created on a concrete subtidal artificial structure, along with small and large swimthroughs, were used by juvenile spiny lobsters and groupers, sea firs, and adult fishes from five families. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3470https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3470Thu, 16 Sep 2021 19:51:58 +0100Collected Evidence: Collected Evidence: Transplant or seed organisms onto subtidal artificial structures Eleven studies examined the effects of transplanting or seeding species onto subtidal artificial structures on the biodiversity of those structures. Eight studies were on open coastlines in Japan, Italy and Croatia, and one of each was in an inland bay in eastern USA, an estuary in southeast Australia, and on an island coastline in the Singapore Strait. COMMUNITY RESPONSE (2 STUDIES) Overall community composition (1 study): One replicated, paired sites, controlled study in the USA found that transplanting oysters onto subtidal artificial structures altered the combined invertebrate and fish community composition on and around structure surfaces. Overall richness/diversity (1 study): One replicated, paired sites, controlled study in the USA found that transplanting oysters onto subtidal artificial structures increased the combined invertebrate and fish species richness and diversity on and around structure surfaces. Invertebrate richness/diversity (1 study): One randomized, before-and-after study in Singapore reported that transplanting corals onto a subtidal artificial structure increased the coral species richness on structure surfaces. POPULATION RESPONSE (11 STUDIES) Overall abundance (1 study): One replicated, paired sites, controlled study in the USA found that transplanting oysters onto subtidal artificial structures did not increase the combined invertebrate and fish abundance on and around structure surfaces, but that the effects varied for different species. Algal abundance (3 studies): Two replicated, randomized, controlled studies in Italy and Croatia found that the cover of canopy algae transplanted onto subtidal artificial structures increased and/or was higher when transplanted under cages but decreased and/or was lower when left uncaged. One study in Japan reported that the abundance of kelp recruits on a subtidal artificial structure varied depending on the distance from transplanted kelp individuals and the surface orientation. Invertebrate abundance (2 studies): One replicated, randomized, controlled and site comparison study in Australia found that transplanting sea urchins onto a subtidal artificial structure reduced the cover of non-native sea mat on kelps growing on the structure. One randomized, before-and-after study in Singapore reported that transplanting corals increased the coral cover on structure surfaces. Algal reproductive success (1 study): One study in Japan reported that kelp transplanted onto a subtidal artificial structure appeared to reproduce. Invertebrate reproductive success (1 study): One replicated, paired sites, controlled study in the USA reported that oysters transplanted onto subtidal artificial structures appeared to reproduce. Algal survival (5 studies): Three of five replicated studies (including two randomized, controlled studies) in Italy found that the survival of canopy algae transplanted onto subtidal artificial structures varied depending on the wave-exposure and surrounding habitat or the presence and/or mesh size of cages around transplants, while in one the surface orientation had no effect. Two studies reported that no canopy algae transplants survived, and in one this was regardless of the presence of cages. Invertebrate survival (3 studies): One randomized, before-and-after study in Singapore found that the survival of corals transplanted onto a subtidal artificial structure varied depending on the species. One replicated, paired sites, controlled study in the USA found that cleaning activities did not affect survival of transplanted oysters. One replicated, randomized, controlled and site comparison study in Australia simply reported that transplanted sea urchins survived. Algal condition (3 studies): Two replicated studies (including one randomized, controlled study) in Italy found that the growth of canopy algae transplanted onto subtidal artificial structures varied depending on the wave-exposure and surface orientation or the presence of cages around transplants, while in one the mesh size of cages had no effect. One study in Japan simply reported that transplanted kelp grew. Invertebrate condition (2 studies): One randomized, before-and-after study in Singapore reported that the growth of corals transplanted onto a subtidal artificial structure varied depending on the species. One replicated, paired sites, controlled study in the USA reported that cleaning activities did not affect the growth of transplanted oysters. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3471https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3471Fri, 17 Sep 2021 12:57:05 +0100Collected Evidence: Collected Evidence: Transplant or seed organisms onto intertidal artificial structures Ten studies examined the effects of transplanting or seeding species onto intertidal artificial structures on the biodiversity of those structures. Seven studies were in estuaries in southeast Australia and Hong Kong, two were on island coastlines in the Singapore Strait and one was in a port and on an open coastline in southeast Spain. COMMUNITY RESPONSE (5 STUDIES) Overall community composition (3 studies): Three replicated, randomized, controlled studies in Hong Kong and Australia reported that oysters transplanted onto intertidal artificial structures supported macroalgae, mobile invertebrate, non-mobile invertebrate and fish species that were absent from on and around structure surfaces without transplanted oysters. Overall richness/diversity (3 studies): Three replicated, randomized, controlled studies in Hong Kong and Australia found that transplanting oysters onto intertidal artificial structures had mixed effects on the combined macroalgae and invertebrate species richness and/or diversity on structure surfaces, depending on the site and/or the presence and size of grooves and small ridges or ledges on surfaces. Invertebrate richness/diversity (1 study): One replicated, randomized, controlled study in Australia found that transplanting oysters onto intertidal artificial structures increased the mobile invertebrate species richness on structure surfaces. Fish richness/diversity (3 studies): Two of three replicated, randomized studies (including two controlled studies) in Australia found that transplanting oysters and/or coralline algae onto intertidal artificial structures did not increase the fish species richness on and around structure surfaces. One found mixed effects of transplanting oysters, depending on the presence and size of grooves and small ridges on surfaces and the site. POPULATION RESPONSE (10 STUDIES) Overall abundance (2 studies): One of two replicated, randomized, controlled studies in Australia found that transplanting oysters onto intertidal artificial structures did not increase the combined macroalgae and invertebrate abundance on structure surfaces. One study found mixed effects depending on the presence and size of grooves and small ridges/ledges on structure surfaces. Invertebrate abundance (3 studies): Two of three replicated, randomized, controlled studies in Hong Kong and Australia found that transplanting oysters onto intertidal artificial structures had mixed effects on the mobile invertebrate abundance on structure surfaces, depending on the presence of grooves and small ridges or ledges on surfaces and/or the site. One of the studies also found that transplanting oysters increased the non-mobile invertebrate and oyster recruit abundance and decreased barnacle abundance. One found increased oyster and mobile invertebrate abundance. Fish abundance (3 studies): Two of three replicated, randomized studies (including two controlled studies) in Australia found that transplanting oysters and/or coralline algae onto intertidal artificial structures did not increase the fish abundance on and around structure surfaces. One found that fish abundance around transplanted oysters was similar regardless of the presence and size of grooves and small ridges on structure surfaces. Algal survival (1 study): One replicated study in Singapore found that macroalgae transplanted onto an intertidal artificial structure were more likely to survive at mid- and highshore than at lowshore. Invertebrate survival (8 studies): Six of eight studies (including six replicated, three randomized and two controlled studies) in Australia, Spain, Singapore and Hong Kong reported that the survival of mobile invertebrates (seasnails, starfish and/or urchins and anemones) or non-mobile invertebrates (limpets, corals and sponges or oysters) transplanted onto intertidal artificial structures varied depending on the species, site, and/or the presence and size of grooves and small ridges or ledges on structure surfaces. One of the studies found that oyster survival was higher when transplanted into grooves compared with on ridges, while one found that survival in grooves and on ledges varied depending on the site. Two studies simply reported that a proportion of transplanted oysters survived. Algal condition (1 study): One replicated study in Singapore found that the growth of macroalgae transplanted onto an intertidal artificial structure was similar at lowshore, midshore and highshore. Invertebrate condition (2 studies): One study in Singapore reported that the growth of corals and sponges transplanted onto an intertidal artificial structure varied depending on the species. One replicated study in Spain simply reported that transplanted limpets grew. BEHAVIOUR (1 STUDY) Fish behaviour change (1 study): One replicated, randomized, controlled study in Australia found that transplanting oysters and/or coralline algae onto intertidal artificial structures did not increase the time fishes spent interacting with structure surfaces or the number of bites they took, but that benthic fishes took more bites from surfaces with transplanted oysters than from those with transplanted algae and oysters together. These results were true regardless of whether there were grooves and small ridges on structure surfaces. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3472https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3472Fri, 17 Sep 2021 16:55:42 +0100
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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.

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