Settlement performance of the Mediterranean reef-builders Dendropoma cristatum (Biondi 1859) in response to natural bacterial films.

The gastropod Dendropoma cristatum is a biogenic engineer of the central Mediterranean, forming reefs along the lower rocky intertidal fringe with a remarkable ecological role. To understand whether reef-associated biofilm cultivable bacterial and biofilm ageing may trigger the settlement of the juvenile snails, a combination of laboratory techniques and field experiments was used. Reef-associated biofilm cultivable bacteria were isolated, and a settlement-choice experiment was performed in situ on artificial biofilms composed of i) a mixture of six biofilm-forming selected isolates, ii) all the cultivable bacteria, and iii) 13-, 23-, 32-day old biofilms formed under natural conditions. Ove…

The influence of light attenuation on the biogeomorphology of a marine karst cave, the Puerto Princesa Underground River, Palawan, The Philippines

Temporal dynamic of biofilms enhances the settlement of the central-1 Mediterranean reef2 builder Dendropoma cristatum (Biondi, 1859)

Research on marine invertebrate settlement provides baseline knowledge for restoration technique implementation, especially for biogenic engineers with limited dispersion ability. Previously, we determined that the maturity of a biofilm strongly enhances the settlement of the vermetid reef-builder Dendropoma cristatum . In order to elucidate which biofilm features support a higher settlement of this species, we analyse the structure and composition of a marine biofilm over time, through microscopic observations, eukaryotic and prokaryotic fingerprinting analyses and 16S rDNA Illumina sequencing. The vermetid settlement temporal increase matched with the higher biofilm extent on the substrat…

Getting into the groove: Opportunities to enhance the ecological value of hard coastal infrastructure using fine-scale surface textures

Concrete flood defences, erosion control structures, port and harbour facilities, and renewable energy infrastructure are increasingly being built in the world’s coastal regions. There is, however, strong evidence to suggest that these structures are poor surrogates for natural rocky shores, often supporting assemblages with lower species abundance and diversity. Ecological engineering opportunities to enhance structures for biodiversity conservation (and other management goals) are therefore being sought, but the majority of work so far has concentrated on structural design features at the centimetre–meter scale.\ud \ud We deployed concrete tiles with four easily-reproducible fine-scale (m…

The influence of light attenuation on the biogeomorphology of a marine karst cave: A case study of Puerto Princesa Underground River, Palawan, the Philippines

Karst caves are unique biogeomorphological systems. Cave walls offer habitat for microorganisms which in-turn have a geomorphological role via their involvement in rock weathering, erosion and mineralisation. The attenuation of light with distance into caves is known to affect ecology, but the implications of this for biogeomorphological processes and forms have seldom been examined. Here we describe a semi-quantitative microscopy study comparing the extent, structure, and thickness of biocover and depth of endolithic penetration for samples of rock from the Puerto Princesa Underground River system in Palawan, the Philippines, which is a natural UNESCO World Heritage Site.\ud \ud Organic gr…

Substratum recognition as settlement cue for larvae of Dendropoma cristatum (Biondi, 1859)

Despite the ecological relevance of the vermetid bioconstructions in the Mediterranean, little is known about the early life stage of Dendropoma cristatum. This study describes the preference for settlement substrata from D. cristatumlarvae. A field experiment was carried out to test the suitability of crustose coralline algae (CCA), D. cristatumadults and two inorganic substrata as settlement surfaces. The number of settling larvae varied among the four treatments with higher settlement success on organic surfaces. CCA and D. cristatumindividuals seem to promote attachment of young larvae and to induce the metamorphosis in recruits. This is probably due to biological or physical properties…

Biological diversity of the microbial film associated to the central-Mediterranean Dendropoma cristatum (Biondi, 1859) reefs.

Microbial films may provide physical and bio-chemical cues which positively affect the settlement dynamic of a variety of benthic marine organisms, driving the development of ecosystems. Also for the Mediterranean intertidal reef-builder Dendropoma cristatum (Biondi, 1859), biofilm maturity has been found to enhance the settlement pattern. However, the microbial diversity associated with these bioconstructions has never been described. This study investigates the D. cristatum reef bacterial assemblage composition and temporal evolution in two localities in the northwest of Sicily. Biological diversity of the reef-associated biofilm and of 3 progressively older biofims obtained on artificial…

Cool barnacles: Do common biogenic structures enhance or retard rates of deterioration of intertidal rocks and concrete?

Sedentary and mobile organisms grow profusely on hard substrates within the coastal zone and contribute to the deterioration of coastal engineering structures and the geomorphic evolution of rocky shores by both enhancing and retarding weathering and erosion. There is a lack of quantitative evidence for the direction and magnitude of these effects. This study assesses the influence of globally-abundant intertidal organisms, barnacles, by measuring the response of limestone, granite and marine-grade concrete colonised with varying percentage covers of Chthamalus spp. under simulated, temperate intertidal conditions. Temperature regimes at 5 and 10 mm below the surface of each material demons…

The Mediterranean vermetid reefs: distribution and conservation status

The vermetid reef is an intertidal bioconstruction distributed in the warmest waters of the Mediterranean Sea, and is built by the gregarious vermetid gastropodDendropomaspp. cemented by the coralline red algae of the genusNeogoniolithon.Thisbiogenichabitatisonly generically protected under the European Habitat Directive, but to date it is not explicitly taken into account in many conservation plans. Despite the documented local extinction of Dendropomain the some Eastern Mediterranean locations, its role as habitat engineer and the high numbers of ecosystem services provided, vermetid reef is among the least known marine bioconstruction of the Mediterranean. We counted 112 reefs along the …

Investigations into the development and role of a Mediterranean intertidal bioconstruction for coastal conservation: the Vermetid Reef

Vermetid reefs are intertidal biogenic habitats created by a dense aggregation of mollusks, frequently cemented by calcareous algae, and are typical of sub-tropical and warm–temperate rocky shores. These bioconstructions are valuable key-habitats of the coastal zones, increasing their productivity and biological value. In the Mediterranean, the main vermetid reef builders belong to the genus Dendropoma and are associated to encrusting coralline red algae. These organisms are ecosystem engineers protected under international European Legislation, although vermetid reef conservation is limited by a lack of biological and ecological knowledge. The two-way interactions between biota and the phy…

Implication of the biofilm ageing for the settlement of the vermetid gastropod Dendropoma cristatum (Biondi 1857)

Dendropoma cristatumreefs are key-intertidal habitats of the central Mediterranean. Knowledge onD. cristatumbiology is presently scant, particularly on its early life stage. The development of embryos occurs inside the maternal shell, and the crawling larvae settle on hard substrates shortly after hatching. Epilithic biofilm is known to have implications in the settlement of many marine invertebrates; however whether biofilm plays a role in driving the vermetid settlement is unknown. In this study the microbial assemblage ageing is tested as apotentialtriggerforD. cristatumsettlement. A field experiment was set-up to compare the larval settlement rate on removable limestone cubes (5x5x2 cm)…

GLI EFFETTI DEL DISTURBO ANTROPICO SULLA TOPOGRAFIA DEL REEF A VERMETI

Intertidal vermetid reefs could be affected by many human disturbances. Using a microtopography device, the authors analysed the changes induced by the accessibility on the surface topography of the reefs. Human activities seems to be able to induce a decrease in rugosity and a surface smoothing on the outer margin of the reef. These effects are proportional to the accessibility of the site.

RESULTS OF DIFFERENT ANTHROPIC USES ON THE STRUCTURE OF VERMETID REEFS

The biogenic vermetid reef is a key habitat of coastal ecosystems that modifies the shoreline morphology and increases the local biodiversity. Despite its ecological relevance, rarely it is subjected to an accurate management and is often exposed to several human activities. This study aims to distinguish between the effects of different typologies of anthropic uses on the physical structure of the vermetid reef. A comparison between totally protected, partially protected and strongly anthropized reefs has been done and two variables have been analysed: the substratum complexity and the density of reef-building organism. Both the variables show higher values in totally and partially protect…

Drawing the Line at Neglected Marine Ecosystems: Ecology of Vermetid Reefs in a Changing Ocean

Vermetid mollusks form reefs that protect coasts from erosion, regulate sediment transport, serve as carbon sinks, and provide habitat for many fish and invertebrates. This biogenic habitat is found in tropical, sub-tropical, and warmtemperate coastal areas, such as Bermuda, oceanic islands in Brazil, and Hawaii, several locations within the Caribbean and the Mediterranean. These reefs are functionally similar to tropical coral fringing reefs but are built by gregarious vermetid gastropods cemented by a crustose coralline algal species, which probably triggers their settlement. Some descriptive studies in different regions worldwide and comparisons among tropical and Mediterranean reefs con…

LA DIMENSIONE FRATTALE DEI REEF A VERMETI

Fractal geometry can be an useful tool to describe the structural complexity of a vermetid reef. Using fractal analysis of small surfaces, the fractal dimension for the outer rim of some vermetid reefs can be established. A positive correlation between fractal values and the density of Dendropoma petraeum is evident.

DISTRIBUTION AND CONSERVATION NEEDS OF A NEGLECTED ECOSYSTEM: THE MEDITERRANEAN VERMETID REEF

Vermetid reefs are a key intertidal habitat in the Mediterranean. Despite recent evidence of local extinction in the Eastern Mediterranean, their role as habitat engineers and the high numbers of ecosystem services they provide, vermetid reefs are among the least known marine habitats of the Mediterranean. Here we present a literature-based study to assess for the first time their distribution inside the basin and provide evidence of a general lack of protection at Mediterranean scale.

Investigation into the ecosystem services of intertidal bioconstruction in the context of coastal erosion and rock breakdown

Temporal dynamic of biofilms enhances the settlement of the central-Mediterranean reef-builder Dendropoma cristatum (Biondi, 1859).

Abstract Research on marine invertebrate settlement provides baseline knowledge for restoration technique implementation, especially for biogenic engineers with limited dispersion ability. Previously, we determined that the maturity of a biofilm strongly enhances the settlement of the vermetid reef-builder Dendropoma cristatum. To elucidate settlement-related biofilm features, here we analyse the structure and composition of marine biofilms over time, through microscopic observations, eukaryotic and prokaryotic fingerprinting analyses and 16S rDNA Illumina sequencing. The vermetid settlement temporal increase matched with the higher biofilm coverage on the substratum and the reduction of th…

REMOTELY PILOTED AIRCRAFT SYSTEMS (RPAS) APPLICATION FOR STRUCTURE DESCRIPTION OF MEDITERRANEAN VERMETID REEFS

Vermetid gastropods are coastal habitat engineers which build biogenic platforms typical of intertidal rocky shores of central and south -east of the Mediterranean. These bioconstructions create a secondary habitat which increases resource availability and space for organisms, locally transforming the environment and modifying coastal geomorphology. Biological characteristics and physical structure of these bioconstructions are commonly studied by field-based sampling. Nevertheless, a lot of time is required to collect data over large areas of reef, field conditions can impair data collection and direct reef image interpretation may be a challenge due to their intertidal position. In this s…

THE BIO-PROTECTIVE ROLE OF A BIOLOGICAL ENCRUSTATION

Benthic organisms can form a persistent biological layer that mediates processes of rock deterioration and limits the degradation of the underlying surface. In this study we investigated the bioprotective potential of barnacle encrustations against salt weathering processes, and discuss their possible role in enhancing the durability of coastal engineering structures

Relazione tra le densità di Dendropoma petraeum e la microtopografia del reef a vermeti”

CONSERVATION NEEDS FOR THE VERMETID REEFS IN THE MEDITERRANEAN SEA

Vermetid reefs are intertidal bioconstructions typical of many subtropical and temperate coastal areas worldwide. Distributed in the warmest waters of the Mediterranean Sea, the reefs are built by the vermetid gastropod Dendropoma petraeum and the coralline alga Neogoniolithon brassica-florida, two species included in the annexes of the Berna Convention. Vermetid reefs provide a wide set of ecosystem services, such as coastal protection from erosion, regulation of sediment transport and accumulation, serving as carbon deposit and increasing biodiversity at the intertidal level. Despite its vulnerability to several threats, such as pollution, spread of invasive species, ocean acidification a…