Caracterización de los Dinoflagelados como posibles indicadores de cambios hidrográficos en la Provincia de Manabí, durante Marzo-Agosto 2014.
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2015
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Se caracterizó la estructura comunitaria de los dinoflagelados en la zona costera de Manabí y su relación con las variables hidrográficas como temperatura y transparencia entre marzo y agosto de 2014. Para ello se colectaron 30 muestras de fitoplancton, mediante arrastres superficiales por espacio de cinco minutos y verticales de 50-0m, de profundidad. El conteo celular de fitoplancton se lo realizó con una cámara Sedgwick- Rafter previa homogenización de una alícuota de 1 ml, cuyos valores son expresados en cel.ml-1para luego ser extrapolados a cel.m-3, empleando la metodología de semina. Se midió la temperatura superficial del mar, la cual reportó un máximo de 27.0 °C en junio y un mínimo de 24 ºC en marzo, solamente en Pedernales se mantuvo con valores de 27.0 a 26.5 ºC, variando en las demás estaciones. Las transparencias mas clara se presentaron en Crucita y Pedernales, mientras que la estación de menor transparencia fue Puerto López. Los valores de abundancia mas altos de los dinoflagelados se registraron en el periodo de abril (superficie) y julio (columna de agua), con 74490 y 257112 x 104 cel.m-3, respectivamente. Se identificaron 57 especies de dinoflagelados de las cuales las taxas predominantes por abundancia y frecuencia fueron Gonyaulacales 55%, seguido de Peridiniales 22% y Dinophysiales 17%. Se registraron al menos tres especies de mayor importancia relativa en terminos de cantidad y ocurrencia de aparicion: Pyrophacus steinii 27%, Pyrocystys fusiformis 26% y Protoperidinium depressum 25%, siendo estas dos últimas las de mayor abundancia tanto en superficie como en la columna de agua. Mientras que Dinophysis caudata (29223 cél/m3) y Ceratium tripos subsp. semipulchellum (114272 cél/m3), presentaron las más bajas densidades. Se pudo evidenciar que Ceratium tripos subsp. semipulchellum se presentó únicamente en Pedernales donde las temperaturas se mantuvieron con valores de 27.0 a 26.5 ºC, mientras que C. trichoceros respondió en condiciones fluctuantes de temperatura, presentándose en Crucita y Pto. López. Con relación al índice de Shannon-Wiener, presentó valores altos con una diversidad promedio de 3.13 bits/ind, mientras que la riqueza de los grupos de dinoflagelados tendió a incrementarse cuando los valores de temperatura fueron positivos. A través del análisis del coeficiente de correlación de Spearman, se evidenció que las variables físicas (temperatura) presentaron valores significativos moderados con
relación a las variables biológicas, tanto en el nivel superficial como en el vertical, es así que Ceratium furca y C. fusus, registraron correlaciones positivas (0.40), mientras que Protoperidinium depressum presentó una correlación inversa (-0.59). Mediante el análisis de Clasificación (Cluster) la asociacion entre especies mostraron una similaridad del 50 %, mientras que entre estaciones evaluadas de los dinoflagelados, no presentaron diferencia estadísticamente significativa (p>0.05).
Community structure of dinoflagellates in Manabí’s coast, and its relationship with the hydrographic variables such as temperature and transparency between March and August 2014 was characterized. In order to perform this project 30 phytoplankton samples were collected by surface drag with an interval of five minutes; also verticals drag of 50-0m depth were taken. For quantitative analysis, Semina methodology and cell count technique with Sedgwick – Rafter´s cameras were performed. Sea surface temperature was measured, which reported a maximum of 27.0 ° C in June and a minimum of 24 ° C in March, but remained constant in Pedernales with values of 27.0 to 26.5 °C, while varying in other stations. The clearest transparencies were presented in Crucita and Pedernales, while the station with less transparency was Puerto Lopez. The highest values of abundance of dinoflagellates were recorded in the period of April (surface) with 74490 and July (water column) with 257112 x 104 cel/m-3. 57 species of dinoflagellates were identified, in which the dominant taxa by abundance and frequency were Gonyaulacales 55 %, followed by Peridiniales 22 % and Pyrocystales 17 %. There were at least three species of greater relative importance in terms of quantity and occurrence of appearance: Pyrophacus steinii 27 %, Pyrocystys fusiformis 26% and Protoperidinium depressum 25 %, being the last two the most abundant in both area and in column water. Dinophysis caudata with a number of 29223 cells/m3 and Ceratium tripos subsp. semipulchellum (114272 cells/m3), had the lowest densities. It was evident that Ceratium tripos subsp. semipulchellum was presented only in Pedernales where temperatures remained with values of 27.0 to 26.5 ° C, while C. Trichoceros responded in fluctuating temperature conditions, appearing in Crucita and Pto. López. Regarding the Shannon -Wiener index, presented higher values with an average diversity of 3.13 bits/ind, while the wealth of the dinoflagellate groups tended to increase when the temperature values were positive. Through the analysis of the correlation coefficient of Spearman, it became clear that the physical variable (temperature) had moderate significant values in relation to the biological variables, both at the vertical and surface level, showing that Ceratium furca and C. fusus, recorded positive correlation (0.40), while Protoperidinium depressum presented an inverse correlation (-0.59). Finally, by the Classification analysis (Cluster), the association between species showed a similarity of 50%, while among the dinoflagellates stations evaluated, no statistically significant difference was evidenced (p > 0.05).
Community structure of dinoflagellates in Manabí’s coast, and its relationship with the hydrographic variables such as temperature and transparency between March and August 2014 was characterized. In order to perform this project 30 phytoplankton samples were collected by surface drag with an interval of five minutes; also verticals drag of 50-0m depth were taken. For quantitative analysis, Semina methodology and cell count technique with Sedgwick – Rafter´s cameras were performed. Sea surface temperature was measured, which reported a maximum of 27.0 ° C in June and a minimum of 24 ° C in March, but remained constant in Pedernales with values of 27.0 to 26.5 °C, while varying in other stations. The clearest transparencies were presented in Crucita and Pedernales, while the station with less transparency was Puerto Lopez. The highest values of abundance of dinoflagellates were recorded in the period of April (surface) with 74490 and July (water column) with 257112 x 104 cel/m-3. 57 species of dinoflagellates were identified, in which the dominant taxa by abundance and frequency were Gonyaulacales 55 %, followed by Peridiniales 22 % and Pyrocystales 17 %. There were at least three species of greater relative importance in terms of quantity and occurrence of appearance: Pyrophacus steinii 27 %, Pyrocystys fusiformis 26% and Protoperidinium depressum 25 %, being the last two the most abundant in both area and in column water. Dinophysis caudata with a number of 29223 cells/m3 and Ceratium tripos subsp. semipulchellum (114272 cells/m3), had the lowest densities. It was evident that Ceratium tripos subsp. semipulchellum was presented only in Pedernales where temperatures remained with values of 27.0 to 26.5 ° C, while C. Trichoceros responded in fluctuating temperature conditions, appearing in Crucita and Pto. López. Regarding the Shannon -Wiener index, presented higher values with an average diversity of 3.13 bits/ind, while the wealth of the dinoflagellate groups tended to increase when the temperature values were positive. Through the analysis of the correlation coefficient of Spearman, it became clear that the physical variable (temperature) had moderate significant values in relation to the biological variables, both at the vertical and surface level, showing that Ceratium furca and C. fusus, recorded positive correlation (0.40), while Protoperidinium depressum presented an inverse correlation (-0.59). Finally, by the Classification analysis (Cluster), the association between species showed a similarity of 50%, while among the dinoflagellates stations evaluated, no statistically significant difference was evidenced (p > 0.05).
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DINOFLAGELADOS, SEDGWICK - RAFTER, NUTRIENTES, BLOOMS, TRANSPARENCIA