Instituto Biodiversidade Marinha

Rio de Janeiro, Brazil

Instituto Biodiversidade Marinha

Rio de Janeiro, Brazil
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Figueiredo M.A.O.,Institute Pesquisas Jardim Botanico Do Rio Of Janeiro | Figueiredo M.A.O.,Instituto Biodiversidade Marinha | Coutinho R.,Institute Estudos do Mar Almirante Paulo Moreira | Villas-Boas A.B.,Institute Pesquisas Jardim Botanico Do Rio Of Janeiro | And 2 more authors.
Journal of Applied Phycology | Year: 2012

Rhodolith beds are an important source of marine calcium carbonate worldwide. Dense aggregations are found in deep water in the tropical southwestern Atlantic. In order to understand the distribution of coralline algae that build rhodoliths, algae responses were measured in light levels over their depth range. Qualitative samples were obtained by dredging at 90-100 m depth 80 km offshore of Cabo Frio Island, southeastern Brazil. Histological sections indicate that Mesophyllum engelhartii (Foslie) Adey was the most frequent coralline algae in 22 sampling stations. Its lumpy and thin thallus is characterized by raised multiporate sporangial conceptacles, with cells of similar size and shape around the pore canal. Accretion growth rates were below detectable levels for two rhodolith species. Photosynthetic peak was reached at 0. 5-1. 5 % of the maximum surface irradiance (10-30 μmol photons m -2 s -1) showing an extremely narrow P-I curve of net primary production. Readings of primary production at irradiance close to saturation and lower light levels (5 μmol photons m -2 s -1) showed no significant difference, suggesting that rhodoliths are acclimated to restricted light ranges in deep water. © 2012 Springer Science+Business Media B.V.

Villas-Boas A.B.,Institute Pesquisa Jardim Botanico Do Rio Of Janeiro | Villas-Boas A.B.,Institute Estudos do Mar Almirante Paulo Moreira | De Souza Tamega F.T.,Instituto Biodiversidade Marinha | Andrade M.,Institute Pesquisa Jardim Botanico Do Rio Of Janeiro | And 4 more authors.
Cryptogamie, Algologie | Year: 2014

A dense rhodolith bed on deep-water soft bottoms in the Peregrino oil field in Campos Basin, Brazil was recently described. This critical habitat is increasingly subjected to disturbances that promote massive sediment dislodgment. This study aimed to test the combined effects of sediment burial and light attenuation on two main rhodolith-forming coralline algae. Experiments were conducted using the dominant algae Mesophyllum engelhartii and Lithothamnion sp. Color changes were measured as a response to burial with a thin layer of fine and coarse sediments compared to uncovered samples at two natural light levels. A mesocosm system exposed species to combined treatments of light and burial by sediments that mimic drill cuttings. M. engelhartii bleached after 75 days and Lithothamnion sp. earlier than that, at 41 days, when buried by fine sediments. Sediments had a strong negative effect on the photosynthesis of coralline algae species within two weeks. Low light levels are not a problem for these deep-water coralline species, but fine sediments have a negative effect after a relatively short time. Lithothamnion was more sensitive than M. engelhartii in terms of color changes but less sensitive in terms of their fluorescence responses to burial. © 2014 Adac.

Nilssen I.,Statoil | Nilssen I.,Norwegian University of Science and Technology | dos Santos F.,PROOCEANO Servico Oceanografico | Coutinho R.,Institute Estudos do Mar Almirante Paulo Moreira | And 8 more authors.
Marine Environmental Research | Year: 2015

The potential impact of drill cuttings on the two deep water calcareous red algae Mesophyllum engelhartii and Lithothamnion sp. from the Peregrino oil field was assessed. Dispersion modelling of drill cuttings was performed for a two year period using measured oceanographic and discharge data with 24 h resolution. The model was also used to assess the impact on the two algae species using four species specific impact categories: No, minor, medium and severe impact. The corresponding intervals for photosynthetic efficiency (ΦPSIImax) and sediment coverage were obtained from exposure-response relationship for photosynthetic efficiency as function of sediment coverage for the two algae species. The temporal resolution enabled more accurate model predictions as short-term changes in discharges and environmental conditions could be detected. The assessment shows that there is a patchy risk for severe impact on the calcareous algae stretching across the transitional zone and into the calcareous algae bed at Peregrino. © 2015 Elsevier Ltd.

Moreira P.L.,State University of Rio de Janeiro | Ribeiro F.V.,Instituto Biodiversidade Marinha | Creed J.C.,State University of Rio de Janeiro
Biofouling | Year: 2014

This study investigated the use of low salinity as a killing agent for the invasive pest corals Tubastraea coccinea and Tubastraea tagusensis (Dendrophylliidae). Experiments investigated the efficacy of different salinities, the effect of colony size on susceptibility and the influence of length of exposure. Experimental treatments of colonies were carried out in aquaria. Colonies were then fixed onto experimental plates and monitored in the field periodically over a period of four weeks. The killing effectiveness of low salinity depended on the test salinity and the target species, but was independent of colony size. Low salinity was fast acting and prejudicial to survival: discoloration, necrosis, fragmenting and sloughing, exposure of the skeleton and cover by biofoulers occurred post treatment. For T. tagusensis, 50% mortality (LC50) after three days occurred at eight practical salinity units (PSU); for T. coccinea the LC50 was 2 PSU. Exposure to freshwater for 45-120 min resulted in 100% mortality for T. tagusensis, but only the 120 min period was 100% effective in killing T. coccinea. Freshwater is now routinely used for the post-border management of Tubastraea spp. This study also provides insights as to how freshwater may be used as a routine biosecurity management tool when applied pre-border to shipping vectors potentially transporting non-indigenous marine biofouling species. © 2014 © 2014 Taylor & Francis.

Santos L.A.H.D.,State University of Rio de Janeiro | Ribeiro F.V.,Instituto Biodiversidade Marinha | Creed J.C.,State University of Rio de Janeiro
Journal of Experimental Marine Biology and Ecology | Year: 2013

The biological invasion of the scleractinian corals Tubastraea coccinea and Tubastraea tagusensis into the Atlantic has resulted in their juxtaposition with native reef corals. We used microcosm and field experiments to investigate and separate the effects of chemical vs. physical mechanisms potentially responsible for observed antagonistic interactions between the invasive corals and the endemic (southwest Atlantic) reef-building coral Mussismilia hispida. In the short term microcosm experiment M. hispida extruded a substantial amount of mesenterial filaments in an aggressive response to proximity to both invasive species within a few hours. However, in the field only the native coral suffered necrosis, which was visible after only four days. The use of physical barriers to separate chemical and physical effects demonstrated that antagonistic effects were far greater in the absence of a physical barrier than in the partial or complete barrier treatments, so although there is evidence that these invasive corals may produce allelochemicals against possible competitors we demonstrated that the main mechanism Tubastraea spp uses to exclude the native coral species is principally a rapid physical response. © 2013 Elsevier B.V.

PubMed | Statoil, Bielefeld University, Institute Pesquisa Jardim Botanico Do Rio Of Janeiro and Instituto Biodiversidade Marinha
Type: Journal Article | Journal: PloS one | Year: 2016

This paper presents a machine learning based approach for analyses of photos collected from laboratory experiments conducted to assess the potential impact of water-based drill cuttings on deep-water rhodolith-forming calcareous algae. This pilot study uses imaging technology to quantify and monitor the stress levels of the calcareous algae Mesophyllum engelhartii (Foslie) Adey caused by various degrees of light exposure, flow intensity and amount of sediment. A machine learning based algorithm was applied to assess the temporal variation of the calcareous algae size ( mass) and color automatically. Measured size and color were correlated to the photosynthetic efficiency (maximum quantum yield of charge separation in photosystem II, [Formula: see text]) and degree of sediment coverage using multivariate regression. The multivariate regression showed correlations between time and calcareous algae sizes, as well as correlations between fluorescence and calcareous algae colors.

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