386 resultados para Macroalgas Marinhas


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The marine turtles biological characteristics and the impact they have been suffering in consequence of human activities have caused in the last decades the decrease of populations to unsustainable levels. All four of the species described in this paper are registered as endangered in a list by IUCN: Caretta caretta, Lepidochelys olivacea, Chelonia mydas, Dermochelys coriacea. The main causes of such impact include several fishing activities, mostly the surface longline. This paper discusses the monitoring of two foreigner longline fleet along the North East Brazilian coast between October of 2004 and September of 2005. Both operated in the West South Atlantic, one using the Chinese technique and the other the American. The American method s target species is the swordfish (Xiphias gladius), and it is characterized by using squid as bait, J 9/0 offset 5º hook, light sticks and night soaking. It also operates in shallower waters than the Chinese method. The source of information about the efforts and the catches came from onboard observers and were used to calculate the catching rate of turtles over 1000 hooks (CPUE). The American equipment caught more turtles (CPUE = 0,059; N= 103), mainly D. coriacea, while the Chinese longline caught mainly the L. olivacea and presented a CPUE= 0,018 (N= 89). The hooks were most frequently found attached to the mouth of C. caretta, C. mydas, and L. olivacea. The D. coriacea were most frequently caught by hooks externally attached to different parts of their body. There was no significant difference between the hook type catching and most turtles were still alive when released. The results suggest a greater potential of turtle catching by the American method. Besides the statistic tests have showed less interaction between the Chinese equipment and marine turtles, the catches of this fishing technique could have been underestimated due to miscommunication between the onboard observer and the vessel s crew plus the retrieve of the longline during night time

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Since centuries ago, the Asians use seaweed as an important source of feeding and are their greatest world-wide consumers. The migration of these peoples for other countries, made the demand for seaweed to increase. This increasing demand prompted an industry with annual values of around US$ 6 billion. The algal biomass used for the industry is collected in natural reservoirs or cultivated. The market necessity for products of the seaweed base promotes an unsustainable exploration of the natural banks, compromising its associated biological balance. In this context, seaweed culture appears as a viable alternative to prevent the depletion of these natural supplies. Geographic Information Systems (GIS) provide space and produce information that can facilitate the evaluation of important physical and socio-economic characteristics for the planning of seaweed culture. This objective of this study is to identify potential coastal areas for seaweed culture in the state of Rio Grande do Norte, from the integration of social-environmental data in the SIG. In order to achieve this objective, a geo-referred database composed of geographical maps, nautical maps and orbital digital images was assembled; and a bank of attributes including physical and oceanographical variables (winds, chains, bathymetry, operational distance from the culture) and social and environmental factors (main income, experience with seaweed harvesting, demographic density, proximity of the sheltered coast and distance of the banks) was produced. In the modeling of the data, the integration of the space database with the bank of attributes for the attainment of the map of potentiality of seaweed culture was carried out. Of a total of 2,011 ha analyzed by the GIS for the culture of seaweed, around 34% or 682 ha were indicated as high potential, 55% or 1,101 ha as medium potential, and 11% or 228 ha as low potential. The good indices of potentiality obtained in the localities studied demonstrate that there are adequate conditions for the installation of seaweed culture in the state of Rio Grande do Norte

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Since the first description of sulfated polysaccharides from seaweeds, the biological activities of these compounds have been evaluated under different aspects and experimental procedures. Among the broad biological activities presented by seaweed polysaccharides, anticoagulant action appears as a promising function. In this present study we have obtained sulfated polysaccharides from the green seaweed Codium isthmocladium by proteolytic digestion, followed by separation into five fractions (0.3, 0.5, 0.7, 0.9 and 1.2) by sequential acetone precipitation. The chemical analyses have demonstrated that all fractions are composed mainly by sulfated polysaccharides. The anticoagulant activity of these fractions was determined by activated partial thromboplastin time (aPTT) and prothrombin time test (PT) using citrate normal human plasma. None fraction has shown anticoagulant activity by PT test. Furthermore, all of them have shown anticoagulant activity by aPTT test. These results indicated that the molecular targets of these sulfated polysaccharides are mainly in the intrinsic via of the coagulation cascade. Agarose gel electrophoresis in 1,3-diaminopropane acetate buffer, pH 9.0, stained with 0.1% toluidine blue showed the presence of two or three bands in several fractions while the fraction 0.9 showed a single spot. By anion exchange chromatography, the acid polysaccharides from the 0.9 acetone fraction were separated into two new fractions eluted respectively with 2.0 and 3.0 M NaCl. These compounds showed a molecular weight of 6.4 and 7.4 kDa respectively. Chemical analyses and infrared spectroscopy showed that Gal 1 and Gal 2 are sulfated homogalactans and differ one from the other in degree and localization of sulfate groups. aPPT test demonstrated that fractions 2,0 and 3,0M (Gal1 and Gal 2, respectively) have anticoagulant activity. This is the first time that anticoagulant sulfated homogalatans have been isolated from green algae. To prolong the coagulation time to double the baseline value in the aPTT, the required amount of sulfated galactan 1 (6,3mg) was similar to low molecular heparin Clexane®, whereas only 0,7mg of sulfated galactan 2 was needed to obtain the same effect. Sulfated galactan 2 in high doses (250mg) induces platelet aggregation. These results suggest that these galactans from C. isthmocladum have a potential application as an anticoagulant drug

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Studies made with polysaccharides of seaweed have demonstrated that these present important biological and pharmacological activities. These composites had presented "scavenging" activity of free radicals, which is important in the mediation of the inflammatory process and in the pathology of diverse disease. Recently, this "scavenging" property has taken some researches to evaluate the antioxidant capacity from various polysaccharides. Considering the limited research with polysaccharides and knowing its largely employed by the pharmaceutical and foodstuffs industries, we have objective to verify the actions from fucans and galactans as antioxidants. The fucans are found in brown seaweed and the galactans (carrageenans) in red seaweed. The fucans were obtained from seaweed Padina gymnospora (F0.5 e F1.1 fractions), common to our coastline and one another fucan, fucoidan, was of origin commercial and extracted from seaweed Fucus vesiculosus. The λ, κ e ι carrageenans were also of origin commercial. The antioxidant activities were tested in superoxide and hydroxyl systems to generated free radicals and for the inhibition of the lipid peroxidation. The results obtained to inhibition of formation the superoxide radicals demonstrated that all polysaccharides presented scavenging activity of superoxide radicals. The fucoidan, F0.5 and F1.1 fractions presented IC50 of 0.058; 0.243 and 0.243 mg/mL, respectively, while IC50 of the λ, κ and ι carrageenans were 0.046; 0.112 and 0.332 mg/mL, respectively. The results to inhibition of formation the hydroxyl radicals demonstrated that all sample had low effect in the inhibition of the formation of these radicals, except the F0.5. For these radicals the IC50 were 0.157 and 0.353 mg/mL to the fucoidan and F1.1, respectively and 0.357; 0.335 and 0.281 mg/mL to λ, κ and ι carrageenans, respectively. All the samples were capacity to inhibition the peroxidation, it present the IC50 of 1.250; 2.753 and 2.341 mg/mL to fucoidan, F0.5 and F1.1, respectively. Already the λ, κ and ι carrageenans presented the IC50 of 2.697; 0.323 and 0.830 mg/mL, respectively. With these findings, we conclude that polysaccharides used in this study presented activity antioxidant, and that fucoidan and the λ carrageenan show a significant "scavenging" activity for the radicals superoxide and the κ carrageenan a significant inhibitory activity for the lipid peroxidation

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Malaria is a major parasitic disease worldwide, accounting for about 500 million cases and causing 2 million to 3 million deaths annually. Four species are responsible for transmitting this disease to humans: Plasmodium falciparum, Plasmodium vivax, Plasmodium malariae and Plasmodium ovale. The parasite resistance to antimalarial drugs and the usual limitations of the vector control implications are contributing to the spread of the disease. The most of significant advances in the search for new antimalarial drugs is based on natural components, the main ones being currently used antimalarial drugs derived from plants. Research on natural products of marine origin (particularly algae) show that some species possess antiplasmodial activity. Knowing that the coast of Rio Grande do Norte is home to several species of algae, the present study was to evaluate, for the first time, the antimalarial activity of ethanolic extracts of seaweed Spatoglossum schroederi, Gracilaria birdiae and Udotea flabellum against Plasmodium falciparum 3D7 strain tests and in vitro using the murine model (Plasmodium berghei) for evaluation in vivo. These species were ground, macerated with ethanol for 24 hours and the extracts concentrated in rotaevaporador (45 ° C ± 5 ° C). For in vitro tests, the extracts were diluted and tested at concentrations between 100 and 1.56 μg/ml (seven concentrations in triplicate), in order to obtain IC50 of each extract. The cytotoxicity tests with macrophages and BGM were performed using the MTT colorimetric assay. BGM macrophages and cells were distributed in 96 wells per plate (1x 105 to macrophages and 1x104 cells per well for BGM) and incubated for 24h at 37 ° C. The ethanol extracts were diluted and tested at concentrations of 100 to 1,56 μg/ml (seven concentrations in triplicate). After periods of 24 hours of incubation with the extracts, 100 μg of MTT was added to each well, and 3 hours elapsed, the supernatant was removed and added 200 μl of DMSO in each well. The absorbance of each well was obtained by reading on a spectrophotometer at 570 nm filter. To evaluate the acute toxicity in vivo, Swiss mice received a single dose (oral) 2000 mg/kg/animal of each extract tested. The parameters of acute toxicity were observed for 8 days. For in vivo tests, Swiss mice were inoculated with 1x105 erythrocytes infected with P. berghei. The treatment was given first to fourth day after infection with 0.2 ml of the extracts in doses of 1000 and 500 mg//g animal. The negative control group received 0.2 ml of 2% Tween-20, whereas the positive control group received sub-dose of chloroquine (5 mg/kg/animal). The assessment of antimalarial activity was done by suppressing suppressing the parasitemia at 5 and 7 days after infection. The growth inhibition of parasites was determined relative to negative control (% inhibition = parasitaemia in control - parasitemia in sample / parasitemia control x 100), the mortality of animals was monitored daily for 30 days The results showed that algae Spatoglossum schroederi and Udotea flabellum showed antimalarial activity in vitro, with reduced parasitemia of 70.54% and 54, respectively. The extracts of the three algae tested showed moderate to high cytotoxicity. Algae S. schroederi and U. flabellum were active against P. berghei only at doses of 500 mg / kg with reduction ranging from 54.58 to 52.65% for the fifth day and from 32.24 to 47.34% for the seventh day, respectively. No toxicity was observed in vivo at the dose tested, over the 8 days of observation. Although preliminary data, the bioactive components in those possible seaweed may be promising for the development of new anti-malarial drugs

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This work aimed to study the diversity and distribution of marine sea turtles stranded in Potiguar Basin, Rio Grande do Norte, as well as aspects related to feeding behavior associated with human impacts. The study was conducted through the analysis of data from stranded animals, recorded in a daily monitoring in an area bounded on the north by the municipality of Aquiraz, in the state of Ceará, and the east by the municipality of Caicara do Norte, in the state of Rio Grande do Norte. Stranded dead animals were necropsied and for the analysis of the diet of animals, esophagus, stomach and intestines were fixed in 10% formalin and after that, the stomach contents were sorted and stored in 70% alcohol. Representative fragments of these organs were removed for making histological slides, with a view to histological characterization of the digestive tract. 2.046 occurrences of turtles were recorded during the period from 01/01/2010 to 31/12/2012. The Chelonia mydas species showed the highest number of records and it was observed in 66.81 % (N = 1,367) of cases; followed by Eretmochelys imbricata with 4.45 % (N = 91) and by Lepidochelys olivacea with 1.22% (N = 25). The Caretta caretta and Dermochelys coriacea species were, respectively, 0.93 % (N = 19) and 0.05 % (N = 1) records of strandings. In 26.54 % of cases, it was not possible to identify the species. Regarding the spatial distribution, the stretch A was the one that had the highest number of strandings and a larger number of records were registered in the warm months of the year. The dietary analysis showed that C. mydas fed preferentially on algae; C. caretta had a diet with a predominance of the item "coral´s fragments" and E. imbricata species showed preference for an animal origin material. Related to this anthropic interaction, 57.14 % (n = 76) of animals that died at the rehabilitation s base, showed cause of death due to complications from ingesting debris. According to the data presented, the Potiguar Basin presents itself as an area with important diversity and distribution of marine sea turtle as well is characterized as a feeding and nidification area for these species

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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In northeastern Brazil, the extraction of agar has increased considerably in recent decades mainly using macroalgae of the genus Gracilaria. The pressure of the harvest of seaweed of this genus has compromised the sustainability of this natural resource. Given the current framework of decline in production of algae in the state of Rio Grande do Norte, it is necessary the deployment of crops that will assist in the development of coastal areas. This research aimed to develop studies on growth, productivity, efficiency and quality of agar of G. birdiae so as to provide subsidies for crops on commercial scale. The study was carried out in dry and rainy periods using rafts of cultivation. Algal biomass and the physical and chemical parameters of water were measured every fifteen days. In laboratory, the resistance and quality of agar were analyzed. The relative growth rate (TCR) was determined by the formula: RGR = ln (final weight / weight initial). 100 / interval time of sampling. During the study, environmental factors as salinity and temperature remained relatively constant (around 35 PSU and 28°C, respectively). The mean values of biomass ranged around 1952.67 ± 576g in the rainy period and 1925.67 ± 450g in the dry period, and they presented no significant variations. The maximum value of growth (TCR) was recorded in the dry season (7.45%.day-1), with an average over the study of 4.35%.day-1. The yield of agar ranged from 22% to 15%, and its resistance ranged from 850 to 650g. cm². The average obtained for the two periods was approximately 750 g cm². These results demonstrate the great potential of Gracilaria birdiae for mariculture can be used as an sustainable activity for coastal communities

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Macroalgas são organismos tipicamente bentônicos, constituídos por um talo maduro, discreto e reconhecível a olho nu, cuja identificação microscópica é necessária. Diversos estudos foram realizados visando o conhecimento taxonômico em riachos brasileiros, no entanto, são raros os trabalhos que abordam as algas que se desenvolvem nas nascentes destes riachos. de fevereiro a setembro/2007 coletas mensais foram realizadas em nascentes e em suas imediações (solos úmidos dos afloramentos d'água) de quatro riachos na região noroeste do estado de São Paulo. O levantamento taxonômico resultou na identificação de 13 espécies, sendo 54% dos táxons pertencentes a Cyanophyta e 46% a Chlorophyta. Cylindrospermum gorakhpurense, Mougeotia gotlandica, Spirogyra gallica e S. taftiana são registradas pela primeira vez para o Brasil. A flora aquática encontrada diferiu da regional devido à presença de organismos da família Zygnemataceae (Chlorophyta) em estágio reprodutivo. Este tipo de hábitat mostrou-se especialmente favorável à reprodução das Zygnemataceae.