Resumo O objetivo dessa pesquisa foi avaliar o potencial fitobiótico dos óleos de Copaifera langsdorffii (copaíba), Carapa guianensis (andiroba), Attalea speciosa (babaçu), Mauritia flexuosa (buriti) e Caryocar brasiliense (pequi), além de dois tipos de extrato aquoso de Terminalia catappa (amendoeira), como alternativas ao uso de antibióticos com princípios ativos em enrofloxacino ou oxitetraciclina na piscicultura continental. Para isso, foram selecionados cinco patógenos espécie-específicos de elevada ocorrência e disseminação em sistemas de produção piscícola continental. O potencial de virulência das cepas foi avaliado por meio de testes de Gram, catalase e atividade hemolítica, seguido de teste de halo de inibição para os potenciais fitobióticos. Todas as cepas selecionadas apresentaram atividade de virulência in vitro e prosseguiram para a avaliação de inibição, na qual foram mensuradas as zonas inibitórias dos produtos testados, além de analisar seus efeitos bactericida ou bacteriostáticos. Dos produtos avaliados, apenas A. speciosa não apresentou halo inibitório frente aos patógenos analisados, já os óleos de C. brasiliense, M. flexuosa, C. guianensis, C. langsdorffii e o extrato a quente de T. catappa apresentaram efeito bactericida, com resultados superiores (P > 0,05) em comparação ao controle positivo com oxitetraciclina. Os óleos de M. flexuosa e C. langsdorffii mostraram-se competitivos in vitro em comparação ao uso dos antibióticos com princípio ativo de enrofloxacino ou oxitetraciclina, demonstrando ação antibactericida contra Aeromonas hydrophila, A. cavie, A. jandaei e Streptococcus agalactiae.

Abstract The aim of this study was to evaluate the phytobiotic potential of the oils from Copaifera langsdorffii (copaiba), Carapa guianensis (andiroba), Attalea speciosa (babassu), Mauritia flexuosa (buriti), and Caryocar brasiliense (pequi), as well as two types of aqueous extracts from Terminalia catappa (tropical almond), as alternatives to antibiotics containing enrofloxacin or oxytetracycline as active ingredients in continental aquaculture. Five species-specific pathogens with high prevalence and dissemination in continental fish farming systems were selected for the study. The virulence potential of the strains was assessed using Gram staining, catalase, and hemolytic activity tests, followed by inhibition halo assays to evaluate the phytobiotic potential. All selected strains exhibited in vitro virulence activity and were subjected to inhibition evaluations, where the inhibitory zones of the tested products were measured, along with their bactericidal or bacteriostatic effects. Among the evaluated products, only A. speciosa did not exhibit an inhibitory halo against the analyzed pathogens. Conversely, the oils from C. brasiliense, M. flexuosa, C. guianensis, C. langsdorffii, and the hot extract of T. catappa demonstrated bactericidal effects, yielding superior results (P > 0.05) compared to the positive control with oxytetracycline. The oils from M. flexuosa and C. langsdorffii proved to be competitive in vitro compared to antibiotics containing enrofloxacin or oxytetracycline as active ingredients, showing antibacterial action against Aeromonas hydrophila, A. caviae, A. jandaei, and Streptococcus agalactiae.

Abstract This study analyzed the influence of strong and moderate El Niño-Southern Oscillation (ENSO) events on the seasonal and interannual variabilities of the sea surface temperature (SST) in the Western Equatorial Atlantic (WEA) Ocean and how the precipitation over the state of Maranhão, in Brazil, responds to the zonal teleconnection. To evaluate the ENSO magnitude and phase in the four Niño regions (1+2, 3, 3.4, and 4), the SODA 3.3.1 oceanic reanalysis database for the period from 1980 to 2015 was used. Our results showed that the La Niña phase with moderate magnitude was the most predominant among the 70 events analyzed, with Niño 3.4 presenting the highest number (20) of ENSO events (both positive and negative phases). At lag = 0, we found that significant negative correlations prevailed between the WEA SST anomalies and ENSO index, with the region of Niño 3.4 showing the most significant correlations (r = −0.25). The whole events of El Niño and La Niña were, respectively, accompanied by a cooling and a heating of up to −0.6°C or +0.8°C in the WEA Ocean. The WEA SST anomalies during El Niño and La Niña events have, respectively, reduced and increased the precipitation in Maranhão around ± 100 mm in a quarter. Strong El Niño events influence a greater precipitation deficit in Maranhão than moderate El Niño events. Moderate La Niña events have more pronounced influence on the precipitation over Maranhão than strong La Niña events do, especially on the negative anomalies. Our results showed that the central, northern, and eastern tip sectors of the state are the most affected by this zonal teleconnection. We concluded that ENSO’s significant influences on the WEA SST seasonal variability, added to the performance of the Atlantic Meridional Mode (Soares, 2019), determine the quality of the rainy season (March–April–May) in the state of Maranhão.

Resumo O objetivo desta pesquisa foi caracterizar a distribuição dos nutrientes dissolvidos em seis estações de amostragem no estuário do rio Anil (ERA) e caracterizar o sedimento de fundo. A área de estudo é influenciada por um clima tropical e regime macromarés semidiurnas. A amostragem das águas superficiais e sedimentos foi realizada no canal principal em seis estações de amostragem distribuídas ao longo do estuário no período chuvoso (09 de maio) e seco (05 de outubro) durante a primavera. Variáveis físicas foram coletadas com o auxílio de uma sonda multiparâmetro HANNA HI-8424 (temperatura da água, salinidade, pH, oxigênio dissolvido e turbidez) e sonda YSI CTD (condutividade, temperatura e profundidade). Uma draga van Veen foi usada para a coleta de sedimentos de fundo do canal principal. Os resultados sedimentológicos foram heterogêneos. O tamanho do grão variou de areia muito fina a média. Os nutrientes dissolvidos no ERA tinham fontes diferentes dependendo do período sazonal. Insumos continentais e fluviais, evidenciados pelos valores de salinidade, governaram a distribuição dos nutrientes no período chuvoso (janeiro a junho), enquanto as concentrações dos nutrientes foram relacionadas à reciclagem da matéria orgânica no estuário na estação seca (julho a dezembro). A presença de areia no canal principal indica que os sedimentos disponíveis no ERA estão expostos a uma hidrodinâmica intensa. A distribuição dos nutrientes e o tamanho do grão revelaram a ocorrência de diferentes fontes no estuário de acordo com o regime de chuvas e a intensa hidrodinâmica das correntes de maré (macromarés semidiurnas).

Abstract The objective of this research was to characterize the distribution of dissolved nutrients at six sampling stations in the estuary of the Anil River (ARE) and characterize the bottom sediment. The study area is influenced by a tropical climate and semidiurnal macrotidal regime. Sampling of the surface water and sediment was performed in the main channel at six sampling stations distributed along the estuary in the rainy period (May 9th) and dry period (October 5th) during the spring. Physical variables were collected with the aid of a HANNA HI-8424 multi-parameter probe (water temperature, salinity, pH, dissolved oxygen, and turbidity) and YSI CTD (conductivity, temperature, and depth) probe. A van Veen dredge was used for the collection of bottom sediment from the main channel. The sedimentological results were heterogeneous. Grain size ranged from very fine to medium sand. Dissolved nutrients in the ARE had different sources depending on the season. Continental and fluvial inputs, evidenced by salinity values, governed the distribution of nutrients in the rainy period (January to June), whereas nutrient concentrations were related to the recycling of organic material in the estuary in the dry season (July to December). The considerable presence of sand in the main channel indicates that the sediments available in ARE are exposed to intense hydrodynamics. The distribution of nutrients and the grain size revealed the occurrence of different sources in the estuary according to the rainfall regime and the intense hydrodynamics of tidal currents (semidiurnal macrotidal).