Avaliação do efeito sinérgico da acidificação e estressores locais no desempenho fisiológico de algas marinhas: estudo de caso com a espécie de alga vermelha Gracilaria Domingensis

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Biológicas, Programa de Pós-Graduação em Biologia Vegetal, Florianópolis, 2012.A emissão de gases, incrementa o efeito estufa e mudanças no clima, a alta concentração de CO2 acumula carboxila, reduz o pH marinho e os níveis de carbonato disponível para os seres. A amplitude desta mudança oscila por vários motivos, não somente pela emissão de gases poluentes, mas também pela absorção de carbonos nos ecossistemas oceânicos. Modelos sugerem um incremento na concentração de CO2 atmosférico de 350 para 890 Pg de C (1 Pg = 1015 g). Considerando cenários conservadores nas próximas décadas teremos um aumento de temperatura da ordem de 3ºC. Segundo estudos as mudanças da atmosfera e do clima desencadearam um desbalanceamento químico entre compostos como o C e N. Por ação antropogênica seriam manipulados e redistribuídos na nossa biosfera. Preocupados com os estoques naturais de algas da região de Florianópolis-SC montamos ensaios para avaliar o comportamento de Gracilaria domingensis em diferentes concentrações de CO2 e nutrientes, simultaneamente. Colocamos 3 g da alga dentro de um erlenmeyer contendo 500 mL de água marinha e solução nutritiva. Montamos 27 réplicas iguais e mais 9 unidades sem algas (puro, somente com água), totalizando 36 unidades que foram divididas em 4 grandes grupos. Estes grupos, menos o puro, foram submetidos a 3 diferentes concentrações de CO2 (Controle=ambiente, baixo=15mL/min, alto=30mL/min) em 3 diferentes concentrações nutricionais (2mL/L oligotrófico, 4mL/L mesotrófico e 6mL/L hipertrófico de solução nutritiva Vonstosch). Usamos como descritor fisiológico a eficiência fotossintética, a concentração de clorofila e a taxa de crescimento das algas. Observamos como resultado que as algas aceitam o gás em sua nutrição, mas taxas elevadas deste composto diminuem sua atividade fotossintética, teor de clorofila, assim como a sua taxa de crescimento. Este resultado foi comum em mais de um ensaio. Um fato curioso foi a abrupta alteração do pH da solução em rumo a alcalinidade durante o período noturno que ocorreu nos frascos saturados pelo gás. Nossos resultados indicam a existência de um comportamento diferenciado no mecanismo de assimilação de carbono por Gracilaria domingensis. (Rhodophyta), se submetida a altas concentrações do gás CO2.Abstract : The emission of gases, increases the global warming and climate change, the high concentration of CO2 accumulates carboxyl, reduces the pH levels and marine carbonate available to human beings. The extent of this change varies for many reasons, not only for greenhouse gas emissions, but also by the absorption of carbon in ocean ecosystems. Models suggest an increase in atmospheric CO2 concentration from 350 to 890 Pg carbon (1 Pg = 1015 g). Considering scenarios conservative in the coming decades there will be a temperature rise of around 3°C. According to studies the changes of atmosphere and climate triggered an imbalance between nutritional compounds such as C and N. For anthropogenic be manipulated and redistributed in our biosphere. Concerned with the natural stocks of algae in the region of Florianópolis-SC assembled tests to evaluate the behavior of Gracilaria domingensis in different concentrations of CO2 and nutrients simultaneously. 3 g of alga put into an Erlenmeyer flask containing 500 mL of seawater and nutrient solution. We set up 27 identical replicas and more 9 units without algae (pure water only), totaling 36 units that were divided into 4 groups. These groups, less than pure, were divided in three different CO2 concentrations (Environment Control = low, high = 15mL/min and 30mL/min) in 3 different concentrations nutritional (2mL/L = oligotrophic, mesotrophic = 4mL/L and 6mL/L = hypertrophic nutrient solution Vonstosch). We use as a descriptor physiological photosynthetic efficiency, chlorophyll concentration and the growth rate of algae. We note that as a result algae accept gas in their nutrition, but high rates of this compound reduces photosynthetic activity, chlorophyll content, as well as its growth rate. This result was common in more than one assay. A curious fact was the abrupt change in solution pH towards alkalinity during the night occurred in the saturated gas bottles. Our results indicate that there is a different behavior on the mechanism of carbon assimilation by Gracilaria domingensis. (Rhodophyta), if subjected to high concentrations of CO2 gas

Evaluation of impacts of climate change and local stressors on the biotechnological potential of marine macroalgae - a brief theoretical discussion of likely scenarios

Climate change can be associated with variations in the frequency and intensity of extreme temperatures and precipitation events on the local and regional scales. Along coastal areas, flooding associated with increased occupation has seriously impacted products and services generated by marine life, in particular the biotechnological potential that macroalgae hold. Therefore, this paper analyzes the available information on the taxonomy, ecology and physiology of macroalgae and discusses the impacts of climate change and local stress on the biotechnological potential of Brazilian macroalgae. Based on data compiled from a series of floristic and ecological works, we note the disappearance in some Brazilian regions of major groups of biotechnological interest. In some cases, the introduction of exotic species has been documented, as well as expansion of the distribution range of economically important species. We also verify an increase in the similarities between the Brazilian phycogeographic provinces, although they still remain different. It is possible that these changes have resulted from the warming of South Atlantic water, as observed for its surface in southeastern Brazilian, mainly during the winter. However, unplanned urbanization of coastal areas can also produce similar biodiversity losses, which requires efforts to generate long-term temporal data on the composition, community structure and physiology of macroalga

Brazilian Flora 2020: Leveraging the power of a collaborative scientific network

International audienceThe shortage of reliable primary taxonomic data limits the description of biological taxa and the understanding of biodiversity patterns and processes, complicating biogeographical, ecological, and evolutionary studies. This deficit creates a significant taxonomic impediment to biodiversity research and conservation planning. The taxonomic impediment and the biodiversity crisis are widely recognized, highlighting the urgent need for reliable taxonomic data. Over the past decade, numerous countries worldwide have devoted considerable effort to Target 1 of the Global Strategy for Plant Conservation (GSPC), which called for the preparation of a working list of all known plant species by 2010 and an online world Flora by 2020. Brazil is a megadiverse country, home to more of the world's known plant species than any other country. Despite that, Flora Brasiliensis, concluded in 1906, was the last comprehensive treatment of the Brazilian flora. The lack of accurate estimates of the number of species of algae, fungi, and plants occurring in Brazil contributes to the prevailing taxonomic impediment and delays progress towards the GSPC targets. Over the past 12 years, a legion of taxonomists motivated to meet Target 1 of the GSPC, worked together to gather and integrate knowledge on the algal, plant, and fungal diversity of Brazil. Overall, a team of about 980 taxonomists joined efforts in a highly collaborative project that used cybertaxonomy to prepare an updated Flora of Brazil, showing the power of scientific collaboration to reach ambitious goals. This paper presents an overview of the Brazilian Flora 2020 and provides taxonomic and spatial updates on the algae, fungi, and plants found in one of the world's most biodiverse countries. We further identify collection gaps and summarize future goals that extend beyond 2020. Our results show that Brazil is home to 46,975 native species of algae, fungi, and plants, of which 19,669 are endemic to the country. The data compiled to date suggests that the Atlantic Rainforest might be the most diverse Brazilian domain for all plant groups except gymnosperms, which are most diverse in the Amazon. However, scientific knowledge of Brazilian diversity is still unequally distributed, with the Atlantic Rainforest and the Cerrado being the most intensively sampled and studied biomes in the country. In times of “scientific reductionism”, with botanical and mycological sciences suffering pervasive depreciation in recent decades, the first online Flora of Brazil 2020 significantly enhanced the quality and quantity of taxonomic data available for algae, fungi, and plants from Brazil. This project also made all the information freely available online, providing a firm foundation for future research and for the management, conservation, and sustainable use of the Brazilian funga and flora