Sessile Communities Research Articles

Investigating the effect of tobramycin dry powder inhaler on the eradication of Pseudomonas aeruginosa biofilms

Biofilms are sessile communities of microorganisms embedded within a self-generated extracellular polymeric matrix. Such biofilms are found for instance in adults with cystic fibrosis, with pulmonary infections with the Gram-negative bacterium Pseudomonas aeruginosa being particularly common. This infection in CF patients is commonly managed with antibiotic dry powder inhalers, one of which is the aminoglycoside tobramycin. The activity of tobramycin has been well characterized in vitro, but current models that have been used are not very representative for lung infections, and better models would provide a significant advantage as these could be used, for instance, to improve the formulation of dry powder inhalers. For instance, one question that has not been addressed with current models is whether the size of drug particles emitted from a dry powder inhaler influences the efficacy of the anti-biofilm activity of the antibiotic. In this project, we utilized the Next Generation Impactor (NGI), which is a pharmaceutical instrument used to separate particles into size fractions. We used the NGI to separate tobramycin particles into different sizes and tested the influence of these particles on eradication of P. aeruginosa biofilms, which were grown using as colony biofilms that closely mimics conditions in the lung where biofilms are grown on a substrate-air interface. Preliminary evidence indicated smaller tobramycin particles are better in eradication of P. aeruginosa biofilms as compared to larger particles. Our results may represent a step towards improving the formulation of tobramycin dry powder inhalers to be effective in eradicating P. aeruginosa biofilms.

Markov chain analysis of sessile community dynamics in a degraded Philippine reef to support restoration of coral populations

Markov chain analysis of sessile community dynamics in a degraded Philippine reef to support restoration of coral populations

Soluções sanitizantes de cinamaldeído para biofilmes de Pseudomonas aeruginosa formados em superfície de aço inoxidável

Abstract Pseudomonas aeruginosa is an opportunistic pathogen capable of forming biofilms of great relevance to medical microbiology and the food industry. Essential oil (EOs) constituents have been researched as new strategies for the control of biofilms. In the present study cinnamaldehyde was shown to be an effective EO against the planktonic cells of P. aeruginosa strains (p < 0.05). Thus it was used to prepare sanitizing solutions, which were tested against P. aeruginosa biofilms formed on stainless steel surfaces. Cinnamaldehyde showed antibacterial activity against sessile P. aeruginosa cells (p < 0.05). A 100% (5.87 log-reduction) elimination of viable bacterial cells was obtained after treatment with a 6xMIC (0.06% Minimal Inhibitory Concentration) solution for the strain ATCC 9027. Sanitizing cinnamaldehyde solutions can be used as new alternatives to control such microbial sessile communities in food industries.

Antimicrobial Photodynamic Therapy to Control Clinically Relevant Biofilm Infections.

Biofilm describes a microbially-derived sessile community in which microbial cells are firmly attached to the substratum and embedded in extracellular polymeric matrix. Microbial biofilms account for up to 80% of all bacterial and fungal infections in humans. Biofilm-associated pathogens are particularly resistant to antibiotic treatment, and thus novel antibiofilm approaches needed to be developed. Antimicrobial Photodynamic therapy (aPDT) had been recently proposed to combat clinically relevant biofilms such as dental biofilms, ventilator associated pneumonia, chronic wound infections, oral candidiasis, and chronic rhinosinusitis. aPDT uses non-toxic dyes called photosensitizers (PS), which can be excited by harmless visible light to produce reactive oxygen species (ROS). aPDT is a multi-stage process including topical PS administration, light irradiation, and interaction of the excited state with ambient oxygen. Numerous in vitro and in vivo aPDT studies have demonstrated biofilm-eradication or substantial reduction. ROS are produced upon photo-activation and attack adjacent targets, including proteins, lipids, and nucleic acids present within the biofilm matrix, on the cell surface and inside the microbial cells. Damage to non-specific targets leads to the destruction of both planktonic cells and biofilms. The review aims to summarize the progress of aPDT in destroying biofilms and the mechanisms mediated by ROS. Finally, a brief section provides suggestions for future research.

INFLUENCE OF BACTERIAL DIVERSITY AND INTERSPECIES INTERACTIONS ON DRINKING WATER-ASSOCIATED BIOFILMS OF YЕRSINIA ЕNTEROCOLITICA

The capability of the enteropathogenic Yersinia enterocolitica 8081 bio/serotype 1B/O:8 to form binary and multi-species biofilms with defined bacterial strains was studied. The interspecies interactions in the binary biofilms of the enteropathogen with three bacterial isolates from drinking water and water-associated biofilms were assessed. The effect of each individual partner strain for the Y. enterocolitica involvement in the four-species bacterial biofilm was evaluated by excluding one by one the isolates from the sessile community. It was found out that Y. enterocolitica and the tested bacterial strains interact each other in the binary biofilm formation. Moreover, the Y. enterocolitica involvement in the biofilms depends on the partner strain. In the multi-species biofilms, a synergetic effect of one of the bacterial partner strains on the Y. enterocolitica attachment was detected in contrast to the weak inhibitory effect of another one.

Cobalt Complex with Thiazole-Based Ligand as New Pseudomonas aeruginosa Quorum Quencher, Biofilm Inhibitor and Virulence Attenuator.

Pseudomonas aeruginosa is one of the most dreaded human pathogens, because of its intrinsic resistance to a number of commonly used antibiotics and ability to form sessile communities (biofilms). Innovative treatment strategies are required and that can rely on the attenuation of the pathogenicity and virulence traits. The interruption of the mechanisms of intercellular communication in bacteria (quorum sensing) is one of such promising strategies. A cobalt coordination compound (Co(HL)2) synthesized from (E)-2-(2-(pyridin-2-ylmethylene)hydrazinyl)-4-(p-tolyl)thiazole (HL) is reported herein for the first time to inhibit P. aeruginosa 3-oxo-C12-HSL-dependent QS system (LasI/LasR system) and underling phenotypes (biofilm formation and virulence factors). Its interactions with a possible target, the transcriptional activator protein complex LasR-3-oxo-C12-HSL, was studied by molecular modeling with the coordination compound ligand having stronger predicted interactions than those of co-crystallized ligand 3-oxo-C12-HSL, as well as known-binder furvina. Transition metal group 9 coordination compounds may be explored in antipathogenic/antibacterial drug design.

Current Knowledge on Listeria monocytogenes Biofilms in Food-Related Environments: Incidence, Resistance to Biocides, Ecology and Biocontrol.

Although many efforts have been made to control Listeria monocytogenes in the food industry, growing pervasiveness amongst the population over the last decades has made this bacterium considered to be one of the most hazardous foodborne pathogens. Its outstanding biocide tolerance capacity and ability to promiscuously associate with other bacterial species forming multispecies communities have permitted this microorganism to survive and persist within the industrial environment. This review is designed to give the reader an overall picture of the current state-of-the-art in L. monocytogenes sessile communities in terms of food safety and legislation, ecological aspects and biocontrol strategies.

An experimental assessment of impacts of pollution sources on sessile biota in a temperate urbanised estuary

Populations of macro-algae and sessile invertebrates have precipitously declined in urbanised coastal waters in Australia since European occupation. Responses of healthy subtidal sessile assemblages to cumulative impacts and types of urban impacts were measured in one of the most polluted estuaries in Australia - the Derwent Estuary - by transplanting sessile communities established on pavers to locations adjacent to marinas, sewerage outfalls, fish farm cages, and stormwater discharges, each with associated controls. Reef communities translocated to sites adjacent to central urban pollution sources (within 5 km of Hobart) lost canopy-forming algae. Fish farms, marinas, and storm water drains were all characterised by higher filamentous algal cover than their controls. Marinas were associated with losses in canopy and foliose algae. Restoration of subtidal reef near highly urbanised areas is unlikely to be successful until current pollution levels are dramatically reduced.

Biodiversity in canopy-forming algae: Structure and spatial variability of the Mediterranean Cystoseira assemblages

In the Mediterranean Sea, Cystoseira species are the most important canopy-forming algae in shallow rocky bottoms, hosting high biodiverse sessile and mobile communities. A large-scale study has been carried out to investigate the structure of the Cystoseira-dominated assemblages at different spatial scales and to test the hypotheses that alpha and beta diversity of the assemblages, the abundance and the structure of epiphytic macroalgae, epilithic macroalgae, sessile macroinvertebrates and mobile macroinvertebrates associated to Cystoseira beds changed among scales. A hierarchical sampling design in a total of five sites across the Mediterranean Sea (Croatia, Montenegro, Sardinia, Tuscany and Balearic Islands) was used. A total of 597 taxa associated to Cystoseira beds were identified with a mean number per sample ranging between 141.1 ± 6.6 (Tuscany) and 173.9 ± 8.5(Sardinia). A high variability at small (among samples) and large (among sites) scale was generally highlighted, but the studied assemblages showed different patterns of spatial variability. The relative importance of the different scales of spatial variability should be considered to optimize sampling designs and propose monitoring plans of this habitat.

Understanding the spatial distribution of subtidal reef assemblages in the southern Baltic Sea using towed camera platform imagery

Quantitative sampling of sessile assemblages on temperate subtidal rocky reefs is expensive and severely time-limited by logistics. However, knowledge about distribution patterns of critical and endangered species and habitats at different spatial scales is needed for effective marine management strategies. To gain information of sessile community distribution on broader spatial scales (>1 km), visual imaging was employed for the first time on a reef complex in the south-western Baltic Sea. Analysis of 3000 images along 6 transects (in total 18 km long) from 10 to 40 m depth revealed high natural variation in reef physical structure, with well-defined changes in sessile species richness, cover and composition. Overall 14 morphological groups could be distinguished by imaging and 4 distinct community groups associated with specific habitat requirements were identified. Depth remained the best descriptor. However, data indicate that light intensity, concentration of organic carbon and suspended particulate matter have an effect on reef community distribution. Compared to fully marine conditions, the study revealed a unique zonation pattern in the circalittoral zone of the Fehmarnbelt brackish transition area, with an unexpected reef habitat in the trench. We conclude that towed camera platform imagery might help to close the information gap regarding rocky reefs in the temperate subtidal. It provides a valuable tool to assess the main distribution patterns of sessile assemblages on rough terrain, potentially applicable for management and conservation planning.

Identifying benthic macrofaunal assemblages and indicator taxa of intertidal boulder fields in the south of the Bay of Biscay (northern Basque coast). A framework for future monitoring

The French southern marine subregion of the Bay of Biscay presents local environmental features explaining the presence of specific communities in remarkable habitats. The aim of the study is, for the first time, to assess benthic macrofaunal assemblages and to identify indicator species of each assemblage within intertidal boulder field habitats in this marine subregion.Mobile boulders were sampled with a stratified random sampling design in upper and lower midlittoral zones in March–June 2015. Sessile (in percentage cover) and mobile macrofauna (in abundance) communities were identified and counted within 0.1 m2 quadrats. Ecological function and precision between the two groups were found dissimilar thus species richness, abundance, macrofauna distribution and indicator species/taxa of sessile and mobile macrofauna were analyzed separately. 78 species/taxa of macrofauna were recorded. A restricted list of 12 singletons (8 for mobile and 4 for sessile macrofauna) and 33 combinations of species/taxa were identified as significant indicators of each assemblage. Species ecological features (food webs, signs of disturbance, alien species, biogeographical range limit) were also considered as additional selection criteria. Therefore, species with a high ecological interest but not considered statistically as valid indicators were also highlighted.Thus, this work constitutes a framework for future monitoring of the Basque intertidal rocky shore and could be used as an alternative to sampling the entire biodiversity. It also meets the MSFD requirements (e.g. take into account marine subregion specificities; integrate the metric “macrofauna” and supports several descriptors as the D1 “Biodiversity” and D6 “Seafloor integrity”).

Effect of garlic solution to Bacillus sp. removal

Biofilm is a microbial derived sessile community characterized by cells that are irreversibly attached to a substratum or interface to each other, embedded in a matrix of extracellular polymeric substances that they have produced. Bacillus sp. was used as biofilm model in this study. The purpose of this study is to determine the effect of Garlic solution in term of ratio of water and Garlic solution (W/G) and ratio of Garlic solution to Bacillus sp. (GS/B) on Bacillus sp removal. Garlic solution was used to remove Bacillus sp. In this study, Garlic solution was prepared by crushing the garlic and mixed it with water. the Garlic solution was added into Bacillus sp. mixture and mixed well. The mixture then was spread on nutrient agar. The Bacillus sp. weight on agar plate was measured by using dry weight measurement method. In this study, initially Garlic solution volume and Garlic solution concentration were studied using one factor at time (OFAT). Later two-level-factorial analysis was done to determine the most contributing factor in Bacillus sp. removal. Design Expert software (Version 7) was used to construct experimental table where all the factors were randomized. Bacilus sp removal was ranging between 42.13% to 99.6%. The analysis of the results showed that at W/G of 1:1, Bacillus sp. removal increased when more Garlic solution was added to Bacillus sp. Effect of Garlic solution to Bacillus sp. will be understood which in turn may be beneficial for the industrial purpose.

Computer simulation study of early bacterial biofilm development

Most bacteria form organized sessile communities, known as biofilms. Their ubiquity and relevance have stimulated the development of efficient mathematical models able to predict biofilm evolution and characteristics at different conditions. Here we present a study of the early stages of bacterial biofilm formation modeled by means of individual cell-based computer simulation. Simulation showed that clusters with different degrees of internal and orientational order were formed as a function of the aspect ratio of the individual particles and the relation between the diffusion and growth rates. Analysis of microscope images of early biofilm formation by the Gram-negative bacterium Pseudomonas putida at varying diffusion rates revealed a good qualitative agreement with the simulation results. Our model is a good predictor of microcolony morphology during early biofilm development, showing that the competition between diffusion and growth rates is a key aspect in the formation of stable biofilm microcolonies.

Persistence and space preemption explain species-specific founder effects on the organization of marine sessile communities.

Community assembly may not follow predictable successional stages, with a large fraction of the species pool constituted by potential pioneering species and successful founders defined through lottery. In such systems, priority effects may be relevant in the determination of trajectories of developing communities and hence diversity and assemblage structure at later advanced states. In order to assess how different founder species may trigger variable community trajectories and structures, we conducted an experimental study using subtidal sessile assemblages as model. We manipulated the identity of functionally different founders and initial colony size (a proxy of the time lag before the arrival of later species), and followed trajectories. We did not observe any effects of colony size on response variables, suggesting that priority effects take place even when the time lag between the establishment of pioneering species and late colonizers is very short. Late community structure at experimental panels that started either with the colonial ascidian Botrylloides nigrum, or the arborescent bryozoan Bugula neritina, was similar to control panels allowed natural assembling. In spite of high potential for fast space domination, and hence negative priority effects, B. nigrum suffered high mortality and did not persist throughout succession. Bugula neritina provided complex physical microhabitats through conspecific clustering that have enhanced larval settlement of late species arrivals, but no apparent facilitation was observed. Differently, panels founded by the encrusting bryozoan Schizoporella errata led to different and less diverse communities compared to naturally assembled panels, evidencing strong negative priority effects through higher persistence and space preemption. Schizoporella errata founder colonies inhibited further conspecific settlement, which may greatly relax intraspecific competition, allowing resource allocation to colony growth and space domination, thus reducing the chances for the establishment of other species.

Mature and developing kelp bed community composition in a glacial estuary

The assembly and maintenance of biological communities is influenced by environmental factors, which are predicted to shift with climate change. Glaciers are melting at increasing rates, delivering sediment and fresh water to coastal habitats. We hypothesized that environmental factors related to glacial discharge would be correlated to the initial recruitment and colonization of sessile communities in kelp beds, and to the abundance of mobile epibenthic invertebrates and adult kelp. To test these hypotheses, cleared rocks were placed at six sites at 10-m depth across a gradient of glacial-influence in Kachemak Bay, Alaska and the percent cover of the initial recruitment and the subsequent progression of the sessile community was monitored over 18months. Small mobile invertebrates (such as limpets and chitons) were also monitored on these rocks for 18months. Lastly, larger invertebrates (such as sea stars) and adult kelp were surveyed over the same time period along transects in the immediate vicinity of the cleared rocks. Environmental factors (sedimentation rates, salinity, temperature, irradiance, and nutrient concentration) were concurrently monitored at each site. Recruitment and subsequent colonization varied along the glacial gradient. At sites with higher sedimentation rates, recruitment and the subsequent developing community was dominated by barnacles with little or no kelp recruits and other macroalgae and high temporal variation in availability of bare space. At more oceanic sites, these communities were characterized by a slow increase in cover of encrusting and upright macroalgae, also with high variability among sites. Mobile invertebrates and adult kelp were more abundant at oceanic sites than the glacial sites. Using distance-based linear models, inorganic sedimentation rate was correlated to patterns of kelp bed recruitment and colonization and to the abundance of mobile invertebrates and adult kelps in the surrounding area. Changes in inorganic sedimentation with climate change may alter how kelp beds are distributed and structured in glacial estuaries.

Conservation of pattern as a tool for inference on spatial snapshots in ecological data

As climate change and other anthropogenic factors increase the uncertainty of vegetation ecosystem persistence, the ability to rapidly assess their dynamics is paramount. Vegetation and sessile communities form a variety of striking regular spatial patterns such as stripes, spots and labyrinths, that have been used as indicators of ecosystem current state, through qualitative analysis of simple models. Here we describe a new method for rigorous quantitative estimation of biological parameters from a single spatial snapshot. We formulate a synthetic likelihood through consideration of the expected change in the correlation structure of the spatial pattern. This then allows Bayesian inference to be performed on the model parameters, which includes providing parameter uncertainty. The method was validated against simulated data and then applied to real data in the form of aerial photographs of seagrass banding. The inferred parameters were found to be able to reproduce similar patterns to those observed and able to detect strength of spatial competition, competition-induced mortality and the local range of reproduction. This technique points to a way of performing rapid inference of spatial competition and ecological stability from a single spatial snapshots of sessile communities.

Structural Analysis of Bordetella pertussis Biofilms by Confocal Laser Scanning Microscopy

Biofilms are sessile communities of microbial cells embedded in a self-produced or host-derived exopolymeric matrix. Biofilms can both be beneficial or detrimental depending on the surface. Compared to their planktonic counterparts, biofilm cells display enhanced resistance to killing by environmental threats, chemicals, antimicrobials and host immune defenses. When in biofilms, the microbial cells interact with each other and with the surface to develop architecturally complex multidimensional structures. Numerous imaging techniques and tools are currently available for architectural analyses of biofilm communities. This allows examination of biofilm development through acquisition of three-dimensional images that can render structural features of the sessile community. A frequently utilized tool is Confocal Laser Scanning Microscopy. We present a detailed protocol to grow, observe and analyze biofilms of the respiratory human pathogen, Bordetella pertussis in space and time.

Dynamics of biofilm formation by Listeria monocytogenes on stainless steel under mono-species and mixed-culture simulated fish processing conditions and chemical disinfection challenges

The progressive ability of a six-strains L. monocytogenes cocktail to form biofilm on stainless steel (SS), under fish-processing simulated conditions, was investigated, together with the biocide tolerance of the developed sessile communities. To do this, the pathogenic bacteria were left to form biofilms on SS coupons incubated at 15°C, for up to 240h, in periodically renewable model fish juice substrate, prepared by aquatic extraction of sea bream flesh, under both mono-species and mixed-culture conditions. In the latter case, L. monocytogenes cells were left to produce biofilms together with either a five-strains cocktail of four Pseudomonas species (fragi, savastanoi, putida and fluorescens), or whole fish indigenous microflora. The biofilm populations of L. monocytogenes, Pseudomonas spp., Enterobacteriaceae, H2S producing and aerobic plate count (APC) bacteria, both before and after disinfection, were enumerated by selective agar plating, following their removal from surfaces through bead vortexing. Scanning electron microscopy was also applied to monitor biofilm formation dynamics and anti-biofilm biocidal actions. Results revealed the clear dominance of Pseudomonas spp. bacteria in all the mixed-culture sessile communities throughout the whole incubation period, with the in parallel sole presence of L. monocytogenes cells to further increase (ca. 10-fold) their sessile growth. With respect to L. monocytogenes and under mono-species conditions, its maximum biofilm population (ca. 6logCFU/cm2) was reached at 192h of incubation, whereas when solely Pseudomonas spp. cells were also present, its biofilm formation was either slightly hindered or favored, depending on the incubation day. However, when all the fish indigenous microflora was present, biofilm formation by the pathogen was greatly hampered and never exceeded 3logCFU/cm2, while under the same conditions, APC biofilm counts had already surpassed 7logCFU/cm2 by the end of the first 96h of incubation. All here tested disinfection treatments, composed of two common food industry biocides gradually applied for 15 to 30min, were insufficient against L. monocytogenes mono-species biofilm communities, with the resistance of the latter to significantly increase from the 3rd to 7th day of incubation. However, all these treatments resulted in no detectable L. monocytogenes cells upon their application against the mixed-culture sessile communities also containing the fish indigenous microflora, something probably associated with the low attached population level of these pathogenic cells before disinfection (<102CFU/cm2) under such mixed-culture conditions. Taken together, all these results expand our knowledge on both the population dynamics and resistance of L. monocytogenes biofilm cells under conditions resembling those encountered within the seafood industry and should be considered upon designing and applying effective anti-biofilm strategies.

Environmental heterogeneity at small spatial scales affects population and community dynamics on intertidal rocky shores of a threatened bay system

Coastal areas are critical transition zones between marine and terrestrial domains that support a large diversity of species but are exposed to significant anthropogenic impacts. While most conservation and management strategies rely on understanding the drivers of diversity over large scales, the importance of small-scale variation in environmental conditions can be overlooked. Here we combined a descriptive and experimental approach to describe the spatio-temporal dynamics of sessile communities and of the population of the barnacle Chthamalus bisinuatus within Araçá Bay, a transition zone in southeastern Brazil threatened by the expansion of the São Sebastião Port. We compared the relative coverage of sessile organisms from rocky shores for 20 months and several population parameters of barnacles in three distinct regions of Araçá Bay, a few hundred meters apart: the inner portion, close to the Mãe Isabel River and the Port, the middle of the Bay, and the outer region, close to the bay entrance. Community structure varied significantly over these small spatial scales; the macroalga Ulva lactuca and the oyster Crassostrea sp. were more abundant in the inner portion of the Bay, where the influence of freshwater and organic pollution from Mãe Isabel River is more intense. Recruitment and density of C. bisinuatus was higher on the shores close to the mouth of the Bay, but individual size increased as one moves into the bay. Experimental manipulation of barnacles originally recruiting at the outer part of the bay and translocated to both outer and inner positions showed that while recruitment is restricted at the inner region, barnacle growth and survival are higher than at the outer shore. Our results suggest that the gradient of physical conditions created along the Araçá Bay can result in distinct dynamics of communities and populations and that the region close to the mouth of the bay is more dynamic, with a larger turnover of space. In the opposite direction, the inner part of the bay, which is closer to the São Sebastião Port, is more prone to be disturbed by any large human modification on the coast as populations are less dynamic and communities tend to be monopolized by species associated with organic pollution. Besides providing useful data for the management of Araçá Bay, our results also show that small-scale variation of environmental conditions can contribute to create distinct dynamics of populations and communities and should be addressed in assessments of environmental impacts on the coast.

Ordinary kriging vs inverse distance weighting: spatial interpolation of the sessile community of Madagascar reef, Gulf of Mexico.

Information about the distribution and abundance of the habitat-forming sessile organisms in marine ecosystems is of great importance for conservation and natural resource managers. Spatial interpolation methodologies can be useful to generate this information from in situ sampling points, especially in circumstances where remote sensing methodologies cannot be applied due to small-scale spatial variability of the natural communities and low light penetration in the water column. Interpolation methods are widely used in environmental sciences; however, published studies using these methodologies in coral reef science are scarce. We compared the accuracy of the two most commonly used interpolation methods in all disciplines, inverse distance weighting (IDW) and ordinary kriging (OK), to predict the distribution and abundance of hard corals, octocorals, macroalgae, sponges and zoantharians and identify hotspots of these habitat-forming organisms using data sampled at three different spatial scales (5, 10 and 20 m) in Madagascar reef, Gulf of Mexico. The deeper sandy environments of the leeward and windward regions of Madagascar reef were dominated by macroalgae and seconded by octocorals. However, the shallow rocky environments of the reef crest had the highest richness of habitat-forming groups of organisms; here, we registered high abundances of octocorals and macroalgae, with sponges, Millepora alcicornis and zoantharians dominating in some patches, creating high levels of habitat heterogeneity. IDW and OK generated similar maps of distribution for all the taxa; however, cross-validation tests showed that IDW outperformed OK in the prediction of their abundances. When the sampling distance was at 20 m, both interpolation techniques performed poorly, but as the sampling was done at shorter distances prediction accuracies increased, especially for IDW. OK had higher mean prediction errors and failed to correctly interpolate the highest abundance values measured in situ, except for macroalgae, whereas IDW had lower mean prediction errors and high correlations between predicted and measured values in all cases when sampling was every 5 m. The accurate spatial interpolations created using IDW allowed us to see the spatial variability of each taxa at a biological and spatial resolution that remote sensing would not have been able to produce. Our study sets the basis for further research projects and conservation management in Madagascar reef and encourages similar studies in the region and other parts of the world where remote sensing technologies are not suitable for use.