MICRORGANISMOS ASSOCIADOS À FLORAÇÕES DA CIANOBACTÉRIA Trichodesmium hildebrandtii NA COSTA DE SANTA CATARINA.

During an oceanographic cruise off Santa Catarina (Lat. 26°S to 27°S) in November/1994 we have observed conspicuous neustonic blooms of the cyanobacteria Trichodesmium hildebrandtii. Two features were distinguished in the blooms: patches composed by brownish healthy colonies (5 colonies/L) and patches composed by whiteness senescent colonies (1200 colonies/L). Quantification of the phytoplankton and protozooplankton associated to the patches revealed densities up to 7 times higher in samples from the senescent bloom than those from the healthy one. According to the results, we suggest that the degree of senescence and decomposition of the cyanobacterial blooms can determines changes in the structure of the associated planktonic assemblages. The bloom as a whole seems to be seasonal and related to the increased influence of tropical water massas in spring and summer months.Durante um cruzeiro oceanográfico na costa de Santa Catarina (Lat. 26°S to 27°S) em Novembro de 1994 foi observada uma conspícua floração da cianobactéria Trichodesmium hildebrandtii. Foram distinguidos dois aspectos na floração: manchas compostas por colônias saudáveis apresentando uma coloração marrom (5 colônias/L) e manchas compostas por colônias senescentes com coloração esbranquiçada (1200 colônias/L). Quantificações do fitoplâncton e do protozooplâncton associados às manchas revelaram densidades de até 7 vezes superiores nas amostras provenientes das manhas de aspecto senescente em relação às do aspecto saudável. De acordo com os resultados, sugere-se que o nível de senescência e decomposição da floração da cianobactéria pode determinar trocas na estrutura das assembléias fitoplanctônicas associadas. A floração como um todo pode ser considerada sazonal e relacionada ao aumento da influência de massas de água tropical nos meses de primavera e verão na costa catarinense

TESTES PRELIMINARES DE CRESCIMENTO COM UMA CEPA DA MICROALGA PRODUTORA DE ASTAXANTINA Haematococcus pluvialis (CHLOROPHYCEAE,VOLVOCALES)

This paper describes a preliminary growth experiment with a strain of the astaxanthin producer Haematococcus pluvialis (Chlorophyceae, Volvocales). Cultures with 4 different cell compositions in terms of density and coloration of aplanospores and macrozooids, were kept under 20°C ± 2°C, 70µE.m-2.s-1, 12h light : 12h dark and appropriate culture media for about 900h. 2ml samples were collected periodically, in order to determine cells density. Results indicated a similar growth pattern to all cultures, where green macrozooids were dominant in the first days being numerically got over by aplanospores after aproximatelly 300h. Maximal number of aplanospores were attained at 800h. The experiment showed that the strain is viable and can be used to physiological studies about optimal growth conditions and astaxanthin production.Este trabalho descreve um experimento preliminar de crescimento com uma cepa da microalga produtora de astaxantina Haematococcus pluvialis (Chlorophyceae, Volvocales). Cultivos com 4 composições diferentes de células em termos de proporção e coloração de aplanósporos e macrozoóides, foram submetidos à 20°C ± 2°C, 70µE.m-2.s-1, fotoperíodo de 12 horas de luz : 12 horas de escuro e meio de cultura adequado por cerca de 900 horas. Alíquotas de 2 ml eram retiradas periodicamente ao longo do experimento para a determinação da densidade de células e construção das curvas de crescimento. Os resultados indicaram um padrão de crescimento similar para todos os frascos de cultivo, onde os macrozoóides predominavam nos primeiros dias sendo substituídos gradualmente por aplanósporos, que tornaram-se dominantes em torno de 300 horas. A densidade máxima de aplanósporos foi verificada em torno das 800 horas de experimento. O experimento como um todo, mostrou que a cepa testada é viável, podendo ser utilizada para experimentos específicos de determinação das condições ótimas de crescimento e produção de astaxantina

ANÁLISE DE TOXINAS DIARRÉICAS EM DUAS ESPÉCIES DE PROROCENTRUM (DINOPHYCEAE) ISOLADAS EM ÁREA DE CULTIVO DE MOLUSCOS.

The diarrhetic shellfish toxins, okadaic acid (OA) and dinophysistoxin 1 (DTX1), are polyeters produced by some species of the Dinophysis and Prorocentrum genera. These toxins can accumulate into the mussel tissues and later intoxicate human consumers. The production of AO and DTX1 by Prorocentrum micans Ehrenberg 1833 and P. obtusum Ostenfeld 1908, two especies isolated from a mussel culture area, was investigated by the pre-column derivatization HPLC-FLD method. Results showed that these two dinoflagellate do not produce AO or DTX1 and they can be ruled out from the potentially toxin producing algae roll find in the mussel culture area.As ficotoxinas ácido ocadaico (AO) e dinofisistoxina 1 (DTX1) são poliéteres produzidos por alguns dinoflagelados dos gêneros Prorocentrum e Dinophysis. Estas toxinas podem ser acumuladas nos tecidos de moluscos filtradores e intoxicar seres humanos que venham a consumir estes moluscos. A produção de AO e DTX1 por duas espécies de dinoflagelados do gênero Prorocentrum, isoladas de uma área de cultivo de moluscos em Santa Catarina, foi investigada pelo método de cromatografia líquida de alta eficiência com derivatização pré-coluna e detecção por fluorescência. Os resultados indicam que as cepas isoladas de P. micans Ehrenberg 1833 and P. obtusum Ostenfeld 1908 não são produtoras de AO ou DTX1 e estes organismos podem ser excluídos do rol das espécies potencialmente produtoras de DSP que ocorrem na região

Avaliação do efeito das águas superficiais dos estuários dos rios Camboriú e Itajaí-açú sobre o crescimento da diatomácea Skeletonema costatum

The Itajaí-Açú and Camboriú rivers are the main important water suppliers for domestic and agroindustrial use in Itajaí and Balneário Camboriú cities in southeastern coast of Brazil. The waste dispoasal by human activities in these estuaries may result in poor water quality and even prevent its use for these activities. In order to evaluate the effects of the human activities upon the estuaries water quality, this study was carried out to evaluate and compare the surface water quality in both estuaries, using a toxicological bioassay to mesure the effect of these waters in growth of marine microalgae Skeletonema costatum (Bacillariophyceae). The samples were colletcted from august of 2003 to march of 2004 in every two weeks at CEPSUL/IBAMA pier (in Itajaí-Açú estuary) and turistic pier (in Camboriú estuary). The physical and chemical characteristics of the samples were determined in situ. The samples were taken to laboratory and frozen for further use. After conducing the bioassay, the results show an increase in algal growth due to excess of nutrients in the samples of both estuaries. This result indicates water eutrophication, as reported in other studies. No effect in the growth of the species was observed for the samples collected in summer months. The samples of march of 2004 from Camboriú estuary were toxic to S. costatum. This result may be due to the disposal of treated wastewater from Balneário Camboriú wastewater treatment plant in the surface river water. The observed concentration effect (CEO) obtained for the samples of march were almost 50%. The CE50 calculated was 96,17% for one sample of march. In the present work, the use of microalgae toxicity test for mesure toxicity in environmental samples and its use as water eutrophication indicator were confirmed.The Itajaí-Açú and Camboriú rivers are the main important water suppliers for domestic and agroindustrial use in Itajaí and Balneário Camboriú cities in southeastern coast of Brazil. The waste dispoasal by human activities in these estuaries may result in poor water quality and even prevent its use for these activities. In order to evaluate the effects of the human activities upon the estuaries water quality, this study was carried out to evaluate and compare the surface water quality in both estuaries, using a toxicological bioassay to mesure the effect of these waters in growth of marine microalgae Skeletonema costatum (Bacillariophyceae). The samples were colletcted from august of 2003 to march of 2004 in every two weeks at CEPSUL/IBAMA pier (in Itajaí-Açú estuary) and turistic pier (in Camboriú estuary). The physical and chemical characteristics of the samples were determined in situ. The samples were taken to laboratory and frozen for further use. After conducing the bioassay, the results show an increase in algal growth due to excess of nutrients in the samples of both estuaries. This result indicates water eutrophication, as reported in other studies. No effect in the growth of the species was observed for the samples collected in summer months. The samples of march of 2004 from Camboriú estuary were toxic to S. costatum. This result may be due to the disposal of treated wastewater from Balneário Camboriú wastewater treatment plant in the surface river water. The observed concentration effect (CEO) obtained for the samples of march were almost 50%. The CE50 calculated was 96,17% for one sample of march. In the present work, the use of microalgae toxicity test for mesure toxicity in environmental samples and its use as water eutrophication indicator were confirmed

MIGRAÇÃO VERTICAL E TAXAS FISIOLÓGICAS DE Thalia democratica (SALPIDAE: THALIACEA) NA RESERVA MARINHA DO ARVOREDO, SANTA CATARINA

Between December 17th and 18th of 1998the Soloncy Moura Research Vessel (CEPSUL/ IBAMA) was stationed for 24 hours at the eastern margin of the Arvoredo island, inside of the Arvoredo Biological Marine Reserve (27°19,6'-27°8,6' S and 48°27,1'-48°9,1' W). During this time the temperature and salinity profiles were obtained using a CTD, and water samples were collected for ammonium determination. The biomass in wet weight of the size classed zooplankton, was collected by vertical trawls in 3 strata in the water column. Incubations were executed at 5 meters depth in DBO flasks, of the Salpidae Thalia democratica Oozooids and the phytoplankton collected in the same place. The filtration rates were estimated by the increase of feopigments and growth rates by blastozooids liberation. The temperature and salinity data measured along the 24 hours didn’t show a significant temporal variation, with the Tropical Water occurring at surface and the Subtropical Water below 20 meters depth. The zooplankton biomass presented a clear vertical migration behaviour, with larger concentrations in the intermediary stratum (10 to 20 m) during the day and with a displacement for the superficial stratum (0 to 10 m) at sunset. The ammonium concentration exhibited a similar behaviour in the water column indicating probable regeneration processes and bioconvection of this nutrient. The species Thalia democratica was the dominant organism in the fraction larger than 1000 µm and it was responsible for the highest zooplankton biomass in the samples. The incubation experiments of this species presented an average filtration rate of 176.4 mL.day-1 and growth rate of blastozooids from 8 to 10.3% in length per hour.Entre os dias 17 e 18 de dezembro de 1998 foi realizado um fundeio na margem leste da ilha do Arvoredo, dentro da Reserva Biológica Marinha do Arvoredo (27o19,6'-27o8,6' S e 48o27,1'- 48o9,1' W), com o Navio de Pesquisa Soloncy Moura (CEPSUL/IBAMA). Durante o fundeio foram realizados perfis de salinidade e temperatura utilizando um CTD bem como coletadas amostras de água para a determinação do amônio. A biomassa em peso úmido do zooplâcton, fracionada em classes de tamanho, foi coletada por arrastos verticais em 3 estratos na coluna de água. Foram executadas incubações a 5 m de profundidade, em frasco tipo DBO, de Oozooides da Salpa Thalia democrática com fitoplâncton coletado no mesmo local para as estimativas de suas taxas de filtração e de suas taxas de crescimento pela liberação de blastozooides. Os dados de temperatura e salinidade medidos durante 22 horas não mostraram uma variação temporal significativa, em que a Água Tropical ocorreu em superfície e a Água Subtropical abaixo dos 20 m de profundidade. A biomassa do zooplâncton apresentou um nítido comportamento de migração vertical, com uma maior concentração no estrato intermediário (10 a 20 m) durante o dia e com um deslocamento para o estrato superficial (0 a 10 m) no entardecer. Comportamento similar ocorreu com a concentração de amônio na coluna de água indicando provável processo de regeneração e bioconvecção deste nutriente. A Salpa Thalia democratica foi o organismo dominante na fração maior que 1000 µm e a responsável pela maior biomassa nas amostras. Os testes de incubação desta espécie apresentaram uma taxa de filtração média de 176,4 mL.dia-1 e taxa de crescimento de blastozooides de 8 a 10,3 % em comprimento por hora

Variabilidade temporal das características oceanográficas e ecológicas da região de influência fluvial do rio Itajaí-açu.

The region of fluvial influence (ROFI) of Itajaí-Açu River was assessed through fourteen surveys covering thirty sampling stations in a radial shape with origin in the estuarine inlet. The total sampled area was of 100 km2 , with depth ranging from 6 to 25 m, and until 10 Km offshore. The surveys were nearly monthly, from October 2002 to December 2003. The variables collected were salinity, temperature, suspended particulate matter, dissolved oxygen, chlorophyll a, picoplankton (autothrophic and heterothrophic) and zooplankton. River discharge and meteorological data were also obtained to help in the general characterization. The results indicated that in terms of averaged values of each variable, the sampling area is poorly related with the river discharge, or in other words, the sampling area is wider than the ROFI. Only salinity showed reasonably agreement with river discharge, although during the winter the region is affected by the Plata estuarine front. Further analysis on the data gathered must cope with spatial variability, either horizontal, e.g., plume dispersion, as vertical, e.g., plume buoyancy flow.The region of fluvial influence (ROFI) of Itajaí-Açu River was assessed through fourteen surveys covering thirty sampling stations in a radial shape with origin in the estuarine inlet. The total sampled area was of 100 km2 , with depth ranging from 6 to 25 m, and until 10 Km offshore. The surveys were nearly monthly, from October 2002 to December 2003. The variables collected were salinity, temperature, suspended particulate matter, dissolved oxygen, chlorophyll a, picoplankton (autothrophic and heterothrophic) and zooplankton. River discharge and meteorological data were also obtained to help in the general characterization. The results indicated that in terms of averaged values of each variable, the sampling area is poorly related with the river discharge, or in other words, the sampling area is wider than the ROFI. Only salinity showed reasonably agreement with river discharge, although during the winter the region is affected by the Plata estuarine front. Further analysis on the data gathered must cope with spatial variability, either horizontal, e.g., plume dispersion, as vertical, e.g., plume buoyancy flow