Maria Luise Koening

Impactos da construção do Porto de Suape sobre a comunidade fitoplanctônica no estuário do rio Ipojuca (Pernambuco-Brasil)

The Suape Industrial Port Complex (Pernambuco-Brazil) constructed between 1979/84 modified the ecology of the area, causing great impacts in the Ipojuca River. In order to assess the impacts on the phytoplankton community comparing with previous studies, samples were obtained at one fixed station in August/90 (rainy season) and in January/91 (dry season). Collections were made in a nyctemeral cycle, every 2 hours by the fraction method and with a plankton net 65 µm mesh size. Hydrological data were collected simultaneously. 97 taxa were identified and the most frequent at both studied period were: Oscillatoria princeps, Chaetoceros lorenzianus, Climacosphenia moniligera and Licmophora abbreviata. Phytoplankton densities ranged from 142,000 cells.l-1 to 1,789,000 cells.l-1 predominating the nanoplankton fraction, being higher in the dry season, during periods of intense sunlight and flood tide. Species diversity was high (> 3 bits.cel.l-1), explained by the environment heterogeneity. The phytoplankton community changed after port construction. Now, there are many littoral species due to the shallow depth and high hydrodinamism of the area and a decrease of 70% in cell density compared to the results obtained before port construction where predominated planktonic species and higher number of cells liter.

Impacts of the construction of the Port of Suape on phytoplankton in the Ipojuca River estuary (Pernambuco-Brazil)

In order to address the impact on phytoplankton, sampling was conducted monthly at 4 fixed stations, from April/86 to March/87 at diurnal low and high tide using a plankton net (65 mm mesh size) and a 1 L Van Dorn bottle. Among the 133 taxa identified, marine littoral euryhaline species were most common, outranking Gyrosigma balticum (Ehrenberg) Rabenhorst, Nitzschia sigma (Kutzing) Wm. Smith, Licmophora abbreviata Agardh, Climacosphenia moniligera Ehrenberg, Surirella febigerii Lewis, Terpsinoe musica Ehrenberg and Cylindrotheca closterium (Ehrenberg) Reiman and Lewis. The port construction caused significant changes to the phytoplankton community with a strong influence of marine species (mainly dinoflagellate) because of the opening of the reef near the river mouth in 1983. The shallow depth and hydrodynamic brought many littoral species to the water columm. The community was composed by marine euryhaline and limnetic organisms, influenced by the salinity, rain and tide. Species diversity was high (> 3 bits.cel-1) owing to the high environmental heterogeneity (marine, freshwater and benthic interactions). After the port implantation, a strong decrease occurred in phytoplankton density owing to high loads of suspended matter. Lowest values (121,00 cells.l-1) were registered during rainy season. During dry season, when light intensity was higher, phytoplankton presented highest density ( 1,789,000 cells.l-1).

Hydrology and phytoplankton community structure at Itamaracá-Pernambuco (Northeast Brazil)

Estudos hidrologicos e fitoplanctonicos foram realizados em dois perfis perpendiculares a costa, em frente a Ilha de Itamaraca-PE (perfis Orange e Catuama), durante a Expedicao do Navio de Pesquisas Victor Hensen, dentro do acordo de cooperacao bilateral celebrado entre o Departamento de Oceanografia da UFPE e o Centro de Ecologia Marinha Tropical (ZMT-Bremen-Alemanha). A camada superficial esta caracterizada por uma zona de estabilidade termica e salina. As concentracoes de nutrientes foram geralmente mais baixas na superficie e mais elevadas em profundidades acima de 100m. Foram identificados 102 taxons, incluindo 49 diatomaceas, 49 dinoflagelados, 3 cianoficeas e 1 euglenoficea. A diversidade especifica e equitabilidade foram elevadas, indicando um equilibrio ambiental. A associacao das amostras evidenciou 2 grupos, um caracterizado por dinoflagelados e diatomaceas, englobando a maioria das estacoes e outro, compreeendendo as estacoes 32 e 38, caracterizadas pelo predominio de Oscillatoria erythraeum. A associacao de especies evidenciou 4 grupos, sendo o maior caracterizado por 49 especies marinhas oceânicas e 31 especies costeiras e eurialinas. A densidade fitoplanctonica variou de 50.000 cels.l-1 a 590.000 cels.l-1 denotando um ambiente oligotrofico.

Spatial and temporal distribution of the phytoplanktonic biomass and environmental variables in the Maranhense Gulf, Brazil

Este trabalho foi desenvolvido com o objetivo de caracterizar alguns estuarios do Golfao Maranhense, atraves da analise da biomassa fitoplanctonica e das variaveis ambientais. As amostras bimestrais foram coletadas em quatro pontos fixos, na superficie, em mare de sizigia, durante a vazante, no periodo de maio/2002 a marco/2003. A pluviometria anual durante o periodo amostrado foi de 1.898,5 mm; a salinidade variou entre 6 e 35; transparencia de 18 a 61 cm; oxigenio dissolvido de 2,1 a 6,3 ml.L-1; taxa de saturacao do oxigenio de 45 a 126%; amonia de 0,02 a 26,45 μM; nitrito de 0,01 a 0,25 μM; nitrato de 0,24 a 3,53 μM e fosfato de 0,13 a 0,58 μM. A concentracao da clorofila a variou de 1,92 a 72,23 mg.m-3 caracterizando esta regiao como de alta produtividade e a fracao <20 μm (nano e picofitoplâncton) foi considerada a mais representativa. AAnalise dos Componentes Principais (ACP) evidenciou que a clorofila a relacionou-se positivamente com a salinidade, transparencia da agua, velocidade do vento, fosfato e nitrato e inversamente com a pluviosidade, oxigenio dissolvido, taxa de saturacao do oxigenio, temperatura e amonia. No Golfao Maranhense forcantes fisicas como vento, macromare e a alta turbidez sao as principais causas da reducao da zona eufotica e consequentemente da biomassa fitoplanctonica.

Chemical compositon of three microalgae species for possible use in mariculture

The purpose of this study was to determine the chemical composition of Chaetoceros gracilis, Cylindrotheca closterium and Tetraselmis gracilis, species frequently used as food for aquaculture in the northeast of Brazil. The species were grown in f/2 medium, in carboys, aerated from one liter, with constant illumination and analyses were made in late exponential growth phase. Cellular density (8,447 x 10 6 cell.L-1), soluble carbohydrates (0.10±0.01 mg.L-1) and magnesium (14.78±0.08 mg.L-1) were the highest in C. gracilis. C . closterium had the highest amount of chlorophyll a (13.76±1.11 mg.L-1), soluble proteins (0.62±0.04 mg.L-1), total amino acids (23.82±0.84 mg .L-1), nitrate (0.36±0.02 mg.L-1), sodium (0.46±0.05 mg.L-1) and phosphorus (2.80±0.38 mg.L-1). Both the species had potassium levels of 0.02 mg.L-1 and sulfur levels of 0.03 mg.L-1. T. gracilis had the lowest values in almost all the analyzed variables, except for chlorophyll a. Therefore, among the analyzed species and tested conditions, C. closterium represented the best nutritional option for aquaculture projects.

Effect of coastline properties and wastewater on plankton composition and distribution in a stressed environment on the north coast of Olinda-PE (Brazil)

Foi realizado um estudo sobre a estrutura das comunidades planctonicas ao longo das praias de Casa Caiada e Rio Doce (Pernanbuco, Brasil). A area de estudo sofre grande influencia antropica onde as condicoes ambientais sao controladas pela presenca de estruturas costeiras, reduzindo a intensidade da circulacao neste ambiente; e pelos efluentes clandestinos de esgoto que aportam aguas poluidas para dentro do sistema protegido. Os resultados obtidos indicam que nas zonas protegidas as aguas apresentam alta turbidez, temperaturas elevadas, salinidades reduzidas e altas concentracoes de nutrientes e oxigenio. Estas condicoes sao responsaveis pela reducao da diversidade do plâncton e pelo aumento da biomassa das especies mais resistentes. As diferencas registradas com respeito a areas similares, porem nao impactadas, parecem indicar que a estrutura planctonica pode ser usada como um indicador da qualidade ambiental, sugerindo uma baixa qualidade das praias em estudo.

Urban secondary sewage: an alternative medium for the culture of Tetraselmis chuii (Prasinophyceae) and Dunaliella viridis (Chlorophyceae)

The effect of different concentrations (10, 20, 30 and 40%) of urban secondary sewage on the growth of Tetraselmis chuii (Prasinophyceae) and Dunaliella viridis (Chlorophyceae) was examined to verify the possibility of its use as an alternative culture medium for these species. Stocks and 700mL duplicate batch cultures were maintained under controlled laboratory conditions. 30% and 40% additions were the most efficient for the growth of both species. Statistical analysis of the adjusted growth (cell.mL-1) and biomass (µg chlorophyll-a.mL-1) curves performed using the Chi-square test (p<0.05) demonstrated significant differences between the nutritive medium f/2 and the 40% addition used for these two species. The results suggested that some of the concentrations tested here yielded satisfactory cell densities and growth rates when compared with other culture media (macroalgae, bovine and chicken manure extracts). Thus it could be used by semi intensive aquaculture systems.

N:Si:P atomic ratio in the Santa Cruz Channel, Itamaracá-PE (Northeast Brazil): a nyctemeral variation

Estudos nas Barras Orange e Catuama do Canal de Santa Cruz, Itamaraca-PE, foram realizados durante os periodos chuvoso e seco, num ciclo nictemeral, com intervalo de 3 horas entre as coletas, numa seccao transversal. O objetivo foi a determinacao da variacao espacial e temporal da relacao N:Si:P, suas possiveis inter-relacoes e dependencias, bem como a influencia das condicoes hidrodinamicas locais, influenciadas pela variacao das mares em diferentes periodos do ano. Nitrito-N e nitrato-N, foram mais elevados no periodo chuvoso, enquanto que amonia-N, fosfato-P e silicato-Si, foram no periodo seco, sendo este resultado diferente de pesquisas anteriores. A relacao N:P foi menor que 16:1, nos diferentes periodos e estacoes, sendo porem, mais elevada no periodo chuvoso e na barra Orange, enquanto que a relacao Si:P esteve sempre superior a 15:1. Neste estudo, o nitrogenio foi o nutriente limitante para o fitoplâncton nesta area. Durante os ciclos nictemerais observados, os principais fatores que influenciaram a composicao dos parâmetros fisicos, quimicos e biologicos foi o ciclo de mares e parâmetros meteorologicos.

New record of Akashiwo sanguinea(Dinophyta) in the tropical estuarine waters of Northeastern Brazil (Western Atlantic)

This study reports the occurrence and the effect of the environmental factors on the spatial and temporal distribution of the dinoflagellate Akashiwo sanguinea (Hirasaka) Hansen & Moestrup in estuarine waters of northeastern Brazil. Samples were collected at seven stations from March 2007 to February 2008 during high tide and low tide, using Van Dorn bottles. The samples were immediately fixed with Lugol and analyzed with the Utermöhl method. Water samples were also collected for the identification of the hydrological characteristics of the area. Akashiwo sanguinea occurred throughout the annual cycle and at all sampling sites with densities ranging between 5 and 410 x 103 cells.L-1. The highest densities were recorded at low tide, especially during the months of the rainy season (July: 210 x 103 cells.L-1; August: 410 x 103 cells.L-1). Density values were within the normal range and blooms were not detected. Despite being common in the area, the species showed preference for sites with high concentrations of orthophosphate and total dissolved phosphorus and with salinity in the mesohaline regime.

Diatomáceas indicadoras de paleoambientes do Quaternário de Dois Irmãos, Recife, PE, Brasil

A study of fossil diatoms from Lagoa das Diatomaceas (Dois Irmaos, Recife) was carried out based on a 4.5-meter-long core sample. Samples were analyzed at 10 cm intervals. A total of 46 taxa were identified in 19 genera, 40 species and six varieties. The stratigraphic column was composed of epiphytic (Actinella, Amphora, Cocconeis Eunotia, Fragilaria, Frustulia, Gomphonema and Rhopalodia), benthic (Navicula, Neidium, Nitzschia, Surirella), and planktonic (Aulacoseira, Cyclotella and Skeletonema) genera. Actinella brasiliensis, Anomoeoneis serians, Eunotia pectinalis and Frustulia rhomboides are oligohalobe, littoral species with high frequency and abundance, which suggests sediment deposition in a limnetic environment. Epiphyte dominance at certain depths confirms the presence of macrophytes during the deposition period. Only seven of the identified species are from a marine environment: Cocconeis heteroidea, Cocconeis scutellum, Diploneis decipiens, Nitzschia scalaris, Nitzschia sigma, Skeletonema costatum and Surirella heideni which occurred sporadically.