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The anthropogenic activities in recent centuries have led to atmospheric changes that directly influence the climate, resulting in global warming. Coastal ecosystems are subjected to global threats by their sensitivity to chemical and... more
The anthropogenic activities in recent centuries have led to atmospheric changes that directly influence the climate, resulting in global warming. Coastal ecosystems are subjected to global threats by their sensitivity to chemical and physical characteristics of seawater and seaweed communities are considered good indicators of environmental changes. This study aimed to evaluate changes in the seaweed flora at Ribanceira Beach (Santa Catarina state, Southern Brazil) by comparing recent to past data (30 years apart), motivated by the possible effects of climate change in this subtropical region, dominated by warm-temperate coastal waters. Significant differences between the past and the current flora were observed. The absence of 17 taxa, observed in the past, and the presence of 16 taxa not reported before in the area are discussed under the perspective of possible global warming effects. acao antropica nos ultimos seculos vem provocando alteracoes atmosfericas que influenciam diret...
Marine pollution caused a growing trend of aesthetic and functional disturbances in coastal ecosystems with environmental, social and economic impairment, with abrupt acceleration in the 1970s. Within these last 50 years, the... more
Marine pollution caused a growing trend of aesthetic and functional disturbances in coastal ecosystems with environmental, social and economic impairment, with abrupt acceleration in the 1970s. Within these last 50 years, the over-enrichment of continental runoff by nutrients has emerged as one of the leading causes of water quality impairment, with tremendous losses for ecosystem services, the foundations to sustain the fishery, aquaculture, recreation and tourism. Most of these scenarios are anthropogenically driven eutrophication (ADE). Algal blooms and oxygen depletion are among the symptoms of a problem that characterizes the anthropocene together with other global stressors. Worldwide, one of the most iconic cases of ADE on beaches is the green tides of Ulva spp., such as those occurred in Qingdao beach, China, in 2008 and the most recent Sargassum bloom in central tropical Atlantic, with floating material observed for 8000 km, from Africa to Central America, highlighting the problem to the global audience. In this chapter, we present the magnitude of ocean eutrophication, their causes and consequences to human beings and marine biodiversity, and potential solutions to increase the resilience of marine environments and coastal communities.
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Research Interests: Geography, Environmental Impact Assessment, Biodiversity, Protected areas, Conservation planning, and 11 moreBiological Sciences, Environmental Sciences, Spatial planning, Threatened species and ecosystems, Ecosystem based management, Connectivity, Conservation Prioritization, Threats, Brazilian coast, Protected Areas, and Cumulative Impacts
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Phylogenetic relationships within sea lettuce species belonging to the genus Ulva is a daunting challenge given the scarcity of diagnostic morphological features and the pervasive phenotypic plasticity. With more than 100 species... more
Phylogenetic relationships within sea lettuce species belonging to the genus Ulva is a daunting challenge given the scarcity of diagnostic morphological features and the pervasive phenotypic plasticity. With more than 100 species described on a morphological basis, an accurate evaluation of its diversity is still missing. Here we analysed 277 chloroplast-encoded gene sequences (43 from this study), representing 35 nominal species of Ulva from the Pacific, Indian Ocean, and Atlantic (with a particular emphasis on the Brazilian coast) in an attempt to solve the complex phylogenetic relationships within this widespread genus. Maximum likelihood, Bayesian analyses and species delimitation tests support the existence of 22 evolutionary significant units (ESUs), lumping the currently recognized number of species. All individuals sampled throughout an extensive area of the Brazilian coast were included within two distinct ESUs. Most of the clades retrieved in the phylogenetic analyses do n...
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RESUMO As algas calcárias não articuladas, representadas pela ordem Corallinales são amplamente distribuídas pelos oceanos, ocorrem desde a zona das marés até regiões profundas e apresentam extrema importância ecológica e econômica.... more
RESUMO As algas calcárias não articuladas, representadas pela ordem Corallinales são amplamente distribuídas pelos oceanos, ocorrem desde a zona das marés até regiões profundas e apresentam extrema importância ecológica e econômica. Apesar destes aspectos, as algas calcárias não articuladas ainda são pouco conhecidas no Brasil. Com o intuito de contribuir para o conhecimento taxonômico desse grupo, neste trabalho são apresentadas descrições de três espécies algas de calcárias não articuladas encontradas no litoral do estado da Bahia: Sporolithon episporum, Mesophyllum erubescens e Lithophyllum stictaeforme.
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Seagrasses live in highly variable light environments and adjust to these variations by expressing acclimatory responses at different plant organizational levels (meadow, shoot, leaf and chloroplast level). Yet, comparative studies, to... more
Seagrasses live in highly variable light environments and adjust to these variations by expressing acclimatory responses at different plant organizational levels (meadow, shoot, leaf and chloroplast level). Yet, comparative studies, to identify species' strategies, and integration of the relative importance of photoacclimatory adjustments at different levels are still missing. The variation in photoacclimatory responses at the chloroplast and leaf level were studied along individual leaves of Cymodocea nodosa, Zostera marina and Z. noltei, including measurements of variable chlorophyll fluorescence, photosynthesis, photoprotective capacities, non-photochemical quenching and D1-protein repair, and assessments of variation in leaf anatomy and chloroplast distribution. Our results show that the slower-growing C. nodosa expressed rather limited physiological and biochemical adjustments in response to light availability, while both species of faster-growing Zostera showed high variab...
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Mycosporine-like amino acids (MAA) are ultraviolet screen substances synthesized by marine algae. The physiological function of these substances is related to cellular protection against UV radiation and as a protective mechanism against... more
Mycosporine-like amino acids (MAA) are ultraviolet screen substances synthesized by marine algae. The physiological function of these substances is related to cellular protection against UV radiation and as a protective mechanism against oxidative stress. These substances can be found mainly in the ocean, among red seaweeds. Its concentration in organisms has been related to ultraviolet radiation and availability of inorganic nitrogen in the environment. We start our study of MAA content in different species to understand if environmental conditions influence the concentration of MAAs in red seaweeds. The Brazilian coast presents abiotic factors that interact to create different physical-chemical features in the environment. We collected 441 samples from 39 species of red seaweed easily found in the intertidal zone, in low tide, during the summer of 2015. The sampling encompassed a latitudinal gradient (3° S to 28°5' S) at 23 points along the coast. We quantified and identified ...
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Seaweeds living at their temperature limits of distribution are naturally exposed to physiological stressors, facing additional stress when exposed to coastal pollution. The physiological responses of seaweeds to environmental conditions... more
Seaweeds living at their temperature limits of distribution are naturally exposed to physiological stressors, facing additional stress when exposed to coastal pollution. The physiological responses of seaweeds to environmental conditions combining natural and anthropogenic stressors provide important information on their vulnerability. We assessed the physiological effects and ultrastructural alterations of trace metals enrichment at concentrations observed in polluted regions within the temperature ranges of distribution of the endemic seaweed Halimeda jolyana, an important component of tropical southwestern Atlantic reefs. Biomass yield and photosynthetic performance declined substantially in samples exposed to metal, although photosynthesis recovered partially at the highest temperature when metal enrichment was ceased. Metal enrichment caused substantial ultrastructural alterations to chloroplasts regardless of temperatures. The lack of photosynthetic recovery at the lower tempe...
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Absorption spectra are indicative of biological sample chemical composition and can be used as a basis for the construction of descriptive and predictive models for biotechnological screening or assays. In marine algae, chemical... more
Absorption spectra are indicative of biological sample chemical composition and can be used as a basis for the construction of descriptive and predictive models for biotechnological screening or assays. In marine algae, chemical composition can vary due to species-specific differences in biochemistry, as well as intra-specific responses to unique environmental variables. Different indices (UVCi, UVB+Ai and PARi) were proposed and calculated to evaluate how photoprotective compounds vary in 18 species of Phaeophyceae. In addition, they were correlated to abiotic factors. Through this technique, seven main peaks were detected in the absorbing spectra of marine brown algal extracts. The highest photoprotective indices values were found in species collected in tropical areas, where higher solar radiation is observed compared to the southern Brazilian coast. Considering additional abiotic factors, water temperature and nitrate concentration were negatively correlated with UV indices. PAR...
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Coastal areas face high variability of seawater pH. Ocean acidification (OA) and local stressors are enhancing this variability, which poses a threat to marine life. However, these organisms present potential phenotypic plasticity that... more
Coastal areas face high variability of seawater pH. Ocean acidification (OA) and local stressors are enhancing this variability, which poses a threat to marine life. However, these organisms present potential phenotypic plasticity that can offer physiological and structural tools to survive in these extreme conditions. In this study, we evaluated the effects of elevated CO2 levels and consequent pH reduction on the physiology, anatomy and ultrastructure of the seagrass Halodule wrightii. A mesocosm study was conducted in an open system during a 30-day experiment, where different concentrations of CO2 were simulated following the natural variability observed in coastal reef systems. This resulted in four experimental conditions simulating the (i) environmental pH (control condition, without CO2 addition) and (ii) reduced pH by - 0.3 units, (iii) - 0.6 units and (iv) - 0.9 units, in relation to the field condition. The evaluated population only suffered reduced optimum quantum yield (...
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Rhodolith beds are important marine benthic ecosystems, representing oases of high biodiversity among sedimentary seabed environments. They are found frequently and abundantly, acting as major carbonate 'factories' and playing a... more
Rhodolith beds are important marine benthic ecosystems, representing oases of high biodiversity among sedimentary seabed environments. They are found frequently and abundantly, acting as major carbonate 'factories' and playing a key role in the biogeochemical cycling of carbonates in the South Atlantic. Rhodoliths are under threat due to global change (mainly related to ocean acidification and global warming) and local stressors, such as fishing and coastal run-off. Here, we review different aspects of the biology of these organisms, highlighting the predicted effects of global change, considering the additional impact of local stressors. Ocean acidification (OA) represents a particular threat that can reduce calcification or even promote the decalcification of these bioengineers, thus increasing the eco-physiological imbalance between calcareous and fleshy algae. OA should be considered, but this together with extreme events such as heat waves and storms, as main stressors ...
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Sargassum cymosum was exposed to cadmium (Cd) to determine any physiological and ultrastructural effects. To accomplish this, S. cymosum samples were cultivated under photosynthetic active radiation (PAR) and Cd (0, 0.1, 0.2, 0.4 and... more
Sargassum cymosum was exposed to cadmium (Cd) to determine any physiological and ultrastructural effects. To accomplish this, S. cymosum samples were cultivated under photosynthetic active radiation (PAR) and Cd (0, 0.1, 0.2, 0.4 and 0.8 mg L(-1)) during 7 and 14 days in laboratory-controlled conditions (0 mg L(-1) Cd at both exposure times as control). Seaweeds had high retention capacity (over 90 %) for both exposure times. Growth rates showed significant increases by 14 days, especially for 0.1 and 0.4 mg L(-1) Cd. Photosynthetic parameters were unaffected by Cd treatments. Chlorophyll contents were present in higher concentrations for all Cd treatments compared to respective control. Carotenoid profile showed significant differences in total composition and proportion of fucoxanthin and β-carotene, and no lutein was detected at 14 days. Phenolic and flavonoid compounds showed major accumulation at 14 days. Transmission electron microscopy (TEM) analyses presented major alteratio...
Research Interests: Principal Component Analysis, Photosynthesis, Plant Biology, Fluorescence, Biology, and 15 moreFlavonoids, Medicine, Multivariate Analysis, Antioxidants, Chlorophyll, Seawater, Cadmium, Seaweed, High Pressure Liquid Chromatography, Phenols, Analysis of Variance, CARBOHYDRATES, Cell Survival, Sargassum, and Biochemistry and cell biology
This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with... more
This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier’s archiving and manuscript policies are encouraged to visit:
Climate change is a global phenomenon that is considered an important threat to marine ecosystems. Ocean acidification and increased seawater temperatures are among the consequences of this phenomenon. The comprehension of the effects of... more
Climate change is a global phenomenon that is considered an important threat to marine ecosystems. Ocean acidification and increased seawater temperatures are among the consequences of this phenomenon. The comprehension of the effects of these alterations on marine organisms, in particular on calcified macroalgae, is still modest despite its great importance. There are evidences that macroalgae inhabiting highly variable environments are relatively resilient to such changes. Thus, the aim of this study was to evaluate experimentally the effects of CO2-driven ocean acidification and temperature rises on the photosynthesis of calcified macroalgae inhabiting the intertidal region, a highly variable environment. The experiments were performed in a reef mesocosm in a tropical region on the Brazilian coast, using three species of frondose calcifying macroalgae (Halimeda cuneata, Padina gymnospora, and Tricleocarpa cylindrica) and crustose coralline algae. The acidification experiment cons...
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An international multi-disciplinary group of 24 researchers met to discuss ocean acidification (OA) during the Brazilian OA Network/Surface Ocean-Lower Atmosphere Study (BrOA/SOLAS) Workshop. Fifteen members of the BrOA Network (... more
An international multi-disciplinary group of 24 researchers met to discuss ocean acidification (OA) during the Brazilian OA Network/Surface Ocean-Lower Atmosphere Study (BrOA/SOLAS) Workshop. Fifteen members of the BrOA Network ( www.broa.furg.br ) authored this review. The group concluded that identifying and evaluating the regional effects of OA is impossible without understanding the natural variability of seawater carbonate systems in marine ecosystems through a series of long-term observations. Here, we show that the western South Atlantic Ocean (WSAO) lacks appropriate observations for determining regional OA effects, including the effects of OA on key sensitive Brazilian ecosystems in this area. The impacts of OA likely affect marine life in coastal and oceanic ecosystems, with further social and economic consequences for Brazil and neighboring countries. Thus, we present (i) the diversity of coastal and open ocean ecosystems in the WSAO and emphasize their roles in the marin...
Research Interests: Geography, Carbon Dioxide, Environmental Management, Brazil, Carbon Cycle, and 15 moreBiodiversity, Ecosystem management, Medicine, Multidisciplinary, Carbonates, Humans, Ocean acidification, Atmosphere, Atlantic Ocean, Seawater, Marine Ecosystems, Ecosystem, South Western Atlantic Ocean, Mitigation and Adaptation, and Oceans and Seas
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Research Interests: Biology and Rhodophyta
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This work describes, for the first time, Dasya rigidula (Kutzing) Ardissone from the south and southeastern Brazil. The specimens presented irregularsubdichotomously branching; variable cortication along the thallus; ocellate apex; and... more
This work describes, for the first time, Dasya rigidula (Kutzing) Ardissone from the south and southeastern Brazil. The specimens presented irregularsubdichotomously branching; variable cortication along the thallus; ocellate apex; and stichidia with four tetrasporangia per segment. Traditionally, the species of this genus are diagnosed depending on the branching parttem, presence of ocellate apex and degree of cortication. Tenuous variations of these characteristics separate Dasya brasiliensis, D. caraibica and Dasya rigidula , and these variations have been observed among specimens of a single popu1ation ana1ysed by us. Nowadays, the number of tetrasporangia per segment of stichidia is used to diagnose species and all the taxa listed above have four, among other common characteristics. We believe that, in the Brazilian coast, they represent the sarne species and should be sinomyzed with Dasya rigidula .