Using a towed underwater video camera system, benthic habitats were classified along transects in a popular offshore fishing area on the West Florida Shelf (WFS) known as “The Elbow.” Additionally, high resolution multibeam bathymetry and co-registered backscatter data were collected for the entire study area. Using these data, full coverage geologic and biotic habitat maps were developed using both unsupervised and supervised statistical classification methodologies. The unsupervised methodology used was k-means clustering, and the supervised methodology used a random forest algorithm. The two methods produced broadly similar results; however, the supervised methodology outperformed the unsupervised methodology. The results of the supervised classification demonstrated “substantial agreement” (κ>0.6) between observations and predictions for both geologic and biotic habitat, while the results of the unsupervised classification demonstrated “moderate agreement” (κ>0.4) between observations and predictions for both geologic and biotic habitat. Comparisons were made with the previously existing map for this area created by Florida Fish and Wildlife Conservation Commission’s Fish and Wildlife Research Institute (FWC-FWRI). Some features are distinguishable in both maps, but the FWC-FWRI map shows a greater extent of low relief hard bottom features than was predicted in our habitat maps. The areas predicted as low relief hard-bottom by FWC-FWRI often coincide with areas of higher uncertainty in the supervised map of geologic habitat from this study, but even when compared with ground-truth points from the towed video rather than predictions, the low relief hard bottom in FWC-FWRI’s map still corresponds to what was identified as sand in the video 73% of the time. The higher uncertainty might be a result of the presence of mixed habitats, differing morphology of hard-bottom, or the presence of sand intermixed with gravel or debris. More ground-truth samples should be taken in these areas to increase the confidence of these classifications and resolve discrepancies between the two maps. Data from the towed video system were also used to assess differences in fish communities among habitat types and to calculate habitat-specific densities for each taxa. Fish communities were found to significantly differ between soft and hard bottom habitats as well as among the hard-bottom habitats with different vertical relief (flat hard-bottom vs more steeply sloping areas). Additionally, significant differences were found between the fish communities in habitats with attached fauna such as sponges and gorgonians, and areas without attached fauna; however, attached fauna require rock to attach to and the rock habitats rarely lacked attached fauna, so this difference may just reflect the difference between fish communities in sand and rock habitats without the consideration of vertical relief. Moreover, the species driving the differences in the fish communities were identified. Fish were more likely to be present and assemblages were more species rich in more complex habitats (rockier, higher relief, presence of attached fauna). Habitat specific densities were calculated for each species, and general trends are discussed. Lastly the habitat-specific densities were extrapolated to the total area of habitat type (sand vs rock) as predicted by the supervised geologic habitat map. There is predicted to be approximately 111,000 fish (95% CI [67015, 169405]) within the study area based on this method, with ~47,000 (~43%) predicted to be within the sand habitat and ~64,000 (~57%) in the rock habitat. This demonstrates the potential of offshore rocky reefs as “critical habitats” for demersal fish in the offshore environment as rock accounts for just 4% of the study area but is expected to contain over half of the total abundance. The value of sand habitats is also shown, as due to their large area they are able to contribute substantially to the total number of fish despite sustaining comparatively low densities.

Apesar dos habitats de restinga representarem aproximadamente 5.000 km da costa brasileira, o conhecimento disponível sobre a composição da fauna de anuros nestes habitats ainda é restrito a poucas áreas. Estes habitats encontram-se sob intensa pressão imobiliária, com uma densidade demográfica cinco vezes maior do que a média do país, levando a uma ocupação descomedida, degradação e eventual perda destes importantes habitats. Isso é especialmente preocupante para as populações de vertebrados terrestres endêmicos e ameaçados de extinção, devido à dificuldade de recuperação da vegetação das restingas. Atualmente, os remanescentes de restinga ao longo da costa brasileira são representados por fragmentos completamente isolados. Esta é a primeira aproximação da lista de anfíbios da restinga de Grumari, inserida no Parque Natural Municipal de Grumari (PNMG), município do Rio de Janeiro, sudeste do Brasil. É também a primeira pesquisa a analisar a comunidade de anuros de folhiço, e a obter dados de densidade, para as restingas brasileiras. A área está situada no Domínio da Mata Atlântica. O estudo foi conduzido de maio de 2009 a dezembro de 2010 utilizando dois métodos de amostragem: parcelas grandes ou plots de 16 m (4x4 m) e transecções visuais/acústicas. Registramos 22 espécies de anfíbios anuros distribuídas em seis famílias: Leptodactylidae (3), Craugastoridae (1), Bufonidae (1), Strabomantidae (1), Microhylidae (2) e Hylidae (14). Ocorreram dez espécies de anuros de folhiço em 2560 m de chão de floresta amostrados com a metodologia de parcelas grandes durante o estudo. Na zona fechada de pós-praia ocorreram apenas sete espécies de anuros de folhiço, enquanto na mata de restinga ocorreram as dez espécies registradas para a restinga. A densidade geral estimada de anuros de folhiço para a restinga de Grumari foi de 13,1 indivíduos por 100m, superior a cinco de seis estudos publicados com dados de densidade de anuros de folhiço na Mata Atlântica. A biomassa total estimada foi de 13131 g/ha, podendo ser considerada a maior biomassa de anurofauna de folhiço globalmente. Não houve diferença estatisticamente significativa entre as zonas quanto aos parâmetros da comunidade (riqueza, densidade e biomassa), mesmo havendo diferença entre os parâmetros ambientais mensurados nas duas zonas. Os fatores que melhor explicaram a riqueza, a densidade e a biomassa na restinga de Grumari durante a estação chuvosa foram, respectivamente, a temperatura, o diâmetro das árvores/arbustos e o número de árvores/arbustos. A presença de espécies ameaçadas de extinção e endêmicas para o estado do Rio de Janeiro e Mata Atlântica evidencia que a restinga de Grumari é uma área essencial para a conservação da anurofauna dos remanescentes deste habitat no Brasil. Além disso, Grumari é a restinga com maior riqueza de espécies do estado e a segunda maior entre todas as áreas de restinga estudadas até o momento, quanto à anurofauna. / Although restinga habitats represent approximately 5000 km of the Brazilian coast, the information available about the composition of the anuran fauna present on those habitats are restricted to relatively few areas. Nowadays restinga habitats are under intense set of pressures as result of a demographic density five times higher than the average for the country leading to the occupation, degradation and eventual loss of such habitats. This is especially alarming for the threatened endemic populations of terrestrial vertebrates due to the difficulty of vegetation recovery after clearings. Presently, the remnants of these habitats along much of the eastern Brazilian coast are represented by completely isolated fragments. Herein we present the first approximation to the list of the amphibians from the restinga of Grumari, inserted in the Parque Natural Municipal de Grumari (PNMG), municipality of Rio de Janeiro, Rio de Janeiro state, southeastern Brazil. The area is situated in the Atlantic Rainforest Biome. Its also the first study on the community of litter anuran fauna, obtaining density data, for the Brazilian restinga. The study was carried out from May 2009 to December 2010 using two sampling methods: quadrant plots (4x4 m) and acoustic/visual transects. We recorded 22 species of anuran amphibians distributed in six families: Leptodactylidae (3), Craugastoridae (1), Bufonidae (1), Strabomantidae (1), Microhylidae (2) and Hylidae (14). We found ten species of litter frogs in 2560 m of sampled forest floor with the methodology of large plots. In the closed post-beach zone, there were only seven species of anuran leaf litter, while the restinga forest zone present the ten species recorded for the restinga. The overall density of litter frogs at the restinga of Grumari was 13.1 individuals per 100m, more than five of six published studies on the density of litter frogs in the Atlantic Rainforest. The estimated total biomass was 13131 g/100m, being currently the area with highest litter frog biomass on the planet. There was no statistically significant difference between the zones regarding community parameters (richness, density and biomass), even though there is difference between the environmental parameters measured in both zones. The factors that best explained the richness, density and biomass in the restinga of Grumari during the rainy season were, respectively, temperature, diameter of the trees/shrubs and the number of trees/shrubs. The presence of endangered and endemic species indicates that the restinga of Grumari is an important area for conservation of the anuran fauna in remnants of these habitats in the Rio de Janeiro state, being currently the richest known area in terms of amphibian species of all restinga areas in the state, and the second richest of the Brazilian restingas studied up to now.

Apesar dos habitats de restinga representarem aproximadamente 5.000 km da costa brasileira, o conhecimento disponível sobre a composição da fauna de anuros nestes habitats ainda é restrito a poucas áreas. Estes habitats encontram-se sob intensa pressão imobiliária, com uma densidade demográfica cinco vezes maior do que a média do país, levando a uma ocupação descomedida, degradação e eventual perda destes importantes habitats. Isso é especialmente preocupante para as populações de vertebrados terrestres endêmicos e ameaçados de extinção, devido à dificuldade de recuperação da vegetação das restingas. Atualmente, os remanescentes de restinga ao longo da costa brasileira são representados por fragmentos completamente isolados. Esta é a primeira aproximação da lista de anfíbios da restinga de Grumari, inserida no Parque Natural Municipal de Grumari (PNMG), município do Rio de Janeiro, sudeste do Brasil. É também a primeira pesquisa a analisar a comunidade de anuros de folhiço, e a obter dados de densidade, para as restingas brasileiras. A área está situada no Domínio da Mata Atlântica. O estudo foi conduzido de maio de 2009 a dezembro de 2010 utilizando dois métodos de amostragem: parcelas grandes ou plots de 16 m (4x4 m) e transecções visuais/acústicas. Registramos 22 espécies de anfíbios anuros distribuídas em seis famílias: Leptodactylidae (3), Craugastoridae (1), Bufonidae (1), Strabomantidae (1), Microhylidae (2) e Hylidae (14). Ocorreram dez espécies de anuros de folhiço em 2560 m de chão de floresta amostrados com a metodologia de parcelas grandes durante o estudo. Na zona fechada de pós-praia ocorreram apenas sete espécies de anuros de folhiço, enquanto na mata de restinga ocorreram as dez espécies registradas para a restinga. A densidade geral estimada de anuros de folhiço para a restinga de Grumari foi de 13,1 indivíduos por 100m, superior a cinco de seis estudos publicados com dados de densidade de anuros de folhiço na Mata Atlântica. A biomassa total estimada foi de 13131 g/ha, podendo ser considerada a maior biomassa de anurofauna de folhiço globalmente. Não houve diferença estatisticamente significativa entre as zonas quanto aos parâmetros da comunidade (riqueza, densidade e biomassa), mesmo havendo diferença entre os parâmetros ambientais mensurados nas duas zonas. Os fatores que melhor explicaram a riqueza, a densidade e a biomassa na restinga de Grumari durante a estação chuvosa foram, respectivamente, a temperatura, o diâmetro das árvores/arbustos e o número de árvores/arbustos. A presença de espécies ameaçadas de extinção e endêmicas para o estado do Rio de Janeiro e Mata Atlântica evidencia que a restinga de Grumari é uma área essencial para a conservação da anurofauna dos remanescentes deste habitat no Brasil. Além disso, Grumari é a restinga com maior riqueza de espécies do estado e a segunda maior entre todas as áreas de restinga estudadas até o momento, quanto à anurofauna. / Although restinga habitats represent approximately 5000 km of the Brazilian coast, the information available about the composition of the anuran fauna present on those habitats are restricted to relatively few areas. Nowadays restinga habitats are under intense set of pressures as result of a demographic density five times higher than the average for the country leading to the occupation, degradation and eventual loss of such habitats. This is especially alarming for the threatened endemic populations of terrestrial vertebrates due to the difficulty of vegetation recovery after clearings. Presently, the remnants of these habitats along much of the eastern Brazilian coast are represented by completely isolated fragments. Herein we present the first approximation to the list of the amphibians from the restinga of Grumari, inserted in the Parque Natural Municipal de Grumari (PNMG), municipality of Rio de Janeiro, Rio de Janeiro state, southeastern Brazil. The area is situated in the Atlantic Rainforest Biome. Its also the first study on the community of litter anuran fauna, obtaining density data, for the Brazilian restinga. The study was carried out from May 2009 to December 2010 using two sampling methods: quadrant plots (4x4 m) and acoustic/visual transects. We recorded 22 species of anuran amphibians distributed in six families: Leptodactylidae (3), Craugastoridae (1), Bufonidae (1), Strabomantidae (1), Microhylidae (2) and Hylidae (14). We found ten species of litter frogs in 2560 m of sampled forest floor with the methodology of large plots. In the closed post-beach zone, there were only seven species of anuran leaf litter, while the restinga forest zone present the ten species recorded for the restinga. The overall density of litter frogs at the restinga of Grumari was 13.1 individuals per 100m, more than five of six published studies on the density of litter frogs in the Atlantic Rainforest. The estimated total biomass was 13131 g/100m, being currently the area with highest litter frog biomass on the planet. There was no statistically significant difference between the zones regarding community parameters (richness, density and biomass), even though there is difference between the environmental parameters measured in both zones. The factors that best explained the richness, density and biomass in the restinga of Grumari during the rainy season were, respectively, temperature, diameter of the trees/shrubs and the number of trees/shrubs. The presence of endangered and endemic species indicates that the restinga of Grumari is an important area for conservation of the anuran fauna in remnants of these habitats in the Rio de Janeiro state, being currently the richest known area in terms of amphibian species of all restinga areas in the state, and the second richest of the Brazilian restingas studied up to now.