[Spoilage of a recreational area due to the effects of a sewage dump]. / Deterioro de un área recreacional por efectos del volcado de líquidos cloacales.

Maldonado is the only municipal bathing resort in Bahía Blanca. Its pool receives water from the estuary of Bahia Blanca. The so-called "Planta de Tratamiento de Líquidos Cloacales para la Tercera Cuenca" located nearby, started to operate in September 2008. It is known that the use of fecal contaminated waters increases the disease risk in the population. The aim of this work was to compare current data with the results obtained in previous studies carried out in the Maldonado bathing resort. Five stations were established to assess the presence of Escherichia coli and Enterococcus spp. Results showed an increase in E. coli counts in the area of interest. The results obtained both in the pool and at the floodgate during the period 2008-2009 showed that fecal indicators in the samples exceeded the levels required for recreational waters by approximately 80%. During time the sampling lasted, the treatment plant did not work properly. Therefore, it is necessary for the involved authorities to design the right strategies to ensure the proper operation of the plant, and to raise general awareness of environmental and health issues.

Detection of somatic coliphages as indicators of faecal contamination in estuarine waters.

The appearance of enteric disease outbreaks associated with the use of waters considered bacteriologically suitable, calls for the search of new and more precise indicators. Samples of estuarine water were collected in order to quantify E. coil and E. coil ATCC 13706 somatic coliphages and to compare the usefulness of the latter to detect faecal contamination when the concentration of traditional indicators is not quantifiable. Statistical analyses suggested the division of sampling sites into two groups: group I and group II, according to the minor or major level of faecal pollution respectively registered. In group II a high correlation between the coliphages and E. coli (r: 0.73 p<0.01) was detected. E. coli always exceeded coliphage abundance. In group I, this relationship was statistically significant (r: 0.55 p<0.05), coliphage counts were higher than those of E. coli and were detected in the absence of the latter. In summary, the use of E. coli ATCC 13706 somatic coliphages is proposed as a complementary tool for the diagnosis of the level of faecal contamination of estuarine waters, especially in areas of low pollution.

Detection of somatic coliphages as indicators of faecal contamination in estuarine waters / Detección de colifagos somáticos como indicadores de contaminación fecal en aguas estuarinas

The appearance of enteric disease outbreaks associated with the use of waters considered bacteriologically suitable, calls for the search of new and more precise indicators. Samples of estuarine water were collected in order to quantify E. coli and E. coli ATCC 13706 somatic coliphages and to compare the usefulness of the latter to detect faecal contamination when the concentration of traditional indicators is not quantifiable. Statistical analyses suggested the division of sampling sites into two groups: group I and group II, according to the minor or major level of faecal pollution respectively registered. In group II a high correlation between the coliphages and E. coli (r: 0.73 p<0.01) was detected. E. coli always exceeded coliphage abundance. In group I, this relationship was statistically significant (r: 0.55 p< 0.05), coliphage counts were higher than those of E. coli and were detected in the absence of the latter. In summary, the use of E. coli ATCC 13706 somatic coliphages is proposed as a complementary tool for the diagnosis of the level of faecal contamination of estuarine waters, especially in areas of low pollution.

La aparición de brotes de enfermedades víricas entéricas asociadas al uso de aguas bacteriológicamente aptas impone la búsqueda de nuevos y más precisos indicadores de contaminación. Se recolectaron muestras de agua estuarina, donde se cuantificaron simultáneamente la bacteria E. coli y los colifagos somáticos de E. coli ATCC 13706, a fin de evaluar la utilidad de estos últimos para detectar contaminación fecal cuando la concentración de los indicadores tradicionales no es cuantificable. Los resultados estadísticos sugirieron la división de las estaciones de muestreo en dos grupos, I y II, de acuerdo con el menor o mayor nivel de contaminación fecal registrado, respectivamente. En el grupo II se detectó una alta correlación entre los recuentos de colifagos y de E. coli (r: 0,73 p<0,01). Asimismo, en este grupo la abundancia de E. coli siempre superó a la de colifagos. En el grupo I la correlación fue estadísticamente significativa (r: 0,55 p < 0,05), pero de mediana magnitud, los recuentos de colifagos superaron a los de E. coli, y éstos fueron detectados aun en ausencia de la bacteria. En conclusión, los colifagos somáticos de E. coli ATCC 13706 serían una herramienta accesoria en el diagnóstico del nivel de contaminación fecal de aguas estuarinas, sobre todo en áreas donde ésta es baja.

Water quality for aquaculture development in Bahía Blanca estuary, Argentina. Bacteriological studies.

The present bacteriological report is part of an institutional multidisciplinary research project designed to study the factibility of using a tidal channel, located in the southern part of the Canal Principal in Bahía Blanca Estuary for aquaculture. Three sampling stations were located. Samples were taken in six opportunities from both water and sediments. Bacteriological studies from water included quantification of heterotrophic marine bacteria, heterotrophic terrestrial bacteria, total coliforms, Escherichia coli and Pseudomonas aeruginosa. Escherichia coli and hydrocarbon-degrading bacteria were quantified from sediments. It is important to include the latter physiological group since their size reflects the presence and fluctuations of this type of pollutant in the environment. The evaluation of faecal indicator values leads to the conclusion that the organic matter present in the studied area, does not come directly from the domestic sewage. The bacteriological data suggest that the studied area would be suitable for aquaculture. Nevertheless, further monitorings contributing to detected modifications in the present bacteriological conditions are recommended.

Water quality for aquaculture development in Bahía Blanca estuary, Argentina. Bacteriological studies

El presente estudio bacteriológico forma parte de un proyecto de investigación institucional multidisciplinario. Tiene por objetivo estudiar la factibilidad de utilizar para acuicultura, un canal de marea, localizado al sur del Canal Principal del Estuario de Bahía Blanca. Se establecieron tres estaciones de muestreo a las que se accedió en seis oportunidades. De cada una de ellas se extrajeron muestras de agua subsuperficial y sedimentos superficiales. En las aguas se cuantificaron bacterias heterótrofas marinas, bacterias heterótrofas terrestres, coliformes totales, Escherichia coli y Pseudomonas aeruginosa, y en los sedimentos Escherichia coli y bacterias degradadoras de hidrocarburos. Se considera importante la inclusión de este último grupo fisiológico debido a que refleja la presencia y fluctuaciones de este tipo de contaminante en el ambiente. La evaluación de los resultados de los indicadores fecales lleva a concluir que la materia orgánica, presente en la zona, no llega directamente de los desagües cloacales que afectan otras áreas del estuario. A partir de los resultados bacteriológicos se considera factible el empleo de la zona estudiada, si bien se deberían continuar los monitoreos a fin de detectar cualquier modificación en las condiciones bacteriológicas actuales

Water quality for aquaculture development in Bahía Blanca estuary, Argentina. Bacteriological studies

El presente estudio bacteriológico forma parte de un proyecto de investigación institucional multidisciplinario. Tiene por objetivo estudiar la factibilidad de utilizar para acuicultura, un canal de marea, localizado al sur del Canal Principal del Estuario de Bahía Blanca. Se establecieron tres estaciones de muestreo a las que se accedió en seis oportunidades. De cada una de ellas se extrajeron muestras de agua subsuperficial y sedimentos superficiales. En las aguas se cuantificaron bacterias heterótrofas marinas, bacterias heterótrofas terrestres, coliformes totales, Escherichia coli y Pseudomonas aeruginosa, y en los sedimentos Escherichia coli y bacterias degradadoras de hidrocarburos. Se considera importante la inclusión de este último grupo fisiológico debido a que refleja la presencia y fluctuaciones de este tipo de contaminante en el ambiente. La evaluación de los resultados de los indicadores fecales lleva a concluir que la materia orgánica, presente en la zona, no llega directamente de los desag³es cloacales que afectan otras áreas del estuario. A partir de los resultados bacteriológicos se considera factible el empleo de la zona estudiada, si bien se deberían continuar los monitoreos a fin de detectar cualquier modificación en las condiciones bacteriológicas actuales(AU)

Water quality for aquaculture development in Bahía Blanca estuary, Argentina. Bacteriological studies.

The present bacteriological report is part of an institutional multidisciplinary research project designed to study the factibility of using a tidal channel, located in the southern part of the Canal Principal in Bahía Blanca Estuary for aquaculture. Three sampling stations were located. Samples were taken in six opportunities from both water and sediments. Bacteriological studies from water included quantification of heterotrophic marine bacteria, heterotrophic terrestrial bacteria, total coliforms, Escherichia coli and Pseudomonas aeruginosa. Escherichia coli and hydrocarbon-degrading bacteria were quantified from sediments. It is important to include the latter physiological group since their size reflects the presence and fluctuations of this type of pollutant in the environment. The evaluation of faecal indicator values leads to the conclusion that the organic matter present in the studied area, does not come directly from the domestic sewage. The bacteriological data suggest that the studied area would be suitable for aquaculture. Nevertheless, further monitorings contributing to detected modifications in the present bacteriological conditions are recommended.

Estudio bacteriológico de aguas marinas para uso recreacional / Bacteriological surveillance of a seawater swimming pool

A fin de decidir la habilitación de una pileta de agua de mar destinada a uso recreacional, la Municipalidad de Bahía Blanca solicitó determinar la calidad bacteriológica de sus aguas. Esto se debió a que la pileta se abastece con agua de la bahía Blanca, que en ese sector del Canal Principal no es apta para baño, como se pudo comprobar en estudios anteriores. Durante tres temporadas estivales se efectuó un estudio integral de las aguas que alimentan la pileta y un monitoreo de la misma. La caracterización se hizo mediante la cuantificación de los grupos bacterianos de heterótrofas aerobias viables, de origen marino y terrestre, coliformes totales, Escherichia coli y Pseudomonas productoras de fluorescencia. Se registraron: temperatura, salinidad, pH del agua y parámetros meteorológicos. En todos los casos los recuentos de indicadores de contaminación fecal, tanto del agua ingresante como de los controles realizados en piletas, estuvieron por debajo de los estándares más rigurosos que existen a nivel mundial para aguas de baño. El trabajo pone en evidencia que en este sistema de planicies de marea no es válida la extrapolación de resultados, y que las condiciones actuales se mantendrán mientras no se produzcan alteraciones en la zona que tiene influencia sobre las planicies de marea adyacentes al balneario

Estudio bacteriológico de aguas marinas para uso recreacional / Bacteriological surveillance of a seawater swimming pool

A fin de decidir la habilitación de una pileta de agua de mar destinada a uso recreacional, la Municipalidad de Bahía Blanca solicitó determinar la calidad bacteriológica de sus aguas. Esto se debió a que la pileta se abastece con agua de la bahía Blanca, que en ese sector del Canal Principal no es apta para baño, como se pudo comprobar en estudios anteriores. Durante tres temporadas estivales se efectuó un estudio integral de las aguas que alimentan la pileta y un monitoreo de la misma. La caracterización se hizo mediante la cuantificación de los grupos bacterianos de heterótrofas aerobias viables, de origen marino y terrestre, coliformes totales, Escherichia coli y Pseudomonas productoras de fluorescencia. Se registraron: temperatura, salinidad, pH del agua y parámetros meteorológicos. En todos los casos los recuentos de indicadores de contaminación fecal, tanto del agua ingresante como de los controles realizados en piletas, estuvieron por debajo de los estándares más rigurosos que existen a nivel mundial para aguas de baño. El trabajo pone en evidencia que en este sistema de planicies de marea no es válida la extrapolación de resultados, y que las condiciones actuales se mantendrán mientras no se produzcan alteraciones en la zona que tiene influencia sobre las planicies de marea adyacentes al balneario (AU)

[Bacteriological study of seawater for recreational use]. / Estudio bacteriológico de aguas marinas para uso recreacional.

A study was conducted at the request of the authorities of the Municipality of Bahía Blanca city, in order to decide whether the sea-water of a swimming pool was suitable for recreational purposes. The characterization of the water was performed through bacteriological indicators and the following groups of bacteria were studied: marine and terrestrial viable aerobic heterotrophic bacteria; total coliforms; Escherichia coli and fluorescent Pseudomonads. Salinity, temperature and pH were registered together with meteorological parameters. In every case, the bacteriological values obtained were lower than those of the most strict international standards used worldwide for bathing waters. In this way, the particular dynamic processing of the water entering the swimming pool from Blanca Bay becomes important, since previous studies conducted on the water of its Principal Channel had yielded high bacteriological values which rendered it unsuitable for bathing. This work shows that in this tidal-flats system, extrapolation of results is not valid. These conditions will remain the same if other factors do not change in the tidal-flats that surround the swimming pool.

Estudio bacteriológico de aguas marinas para uso recreacional. / [Bacteriological study of seawater for recreational use]

A study was conducted at the request of the authorities of the Municipality of Bahía Blanca city, in order to decide whether the sea-water of a swimming pool was suitable for recreational purposes. The characterization of the water was performed through bacteriological indicators and the following groups of bacteria were studied: marine and terrestrial viable aerobic heterotrophic bacteria; total coliforms; Escherichia coli and fluorescent Pseudomonads. Salinity, temperature and pH were registered together with meteorological parameters. In every case, the bacteriological values obtained were lower than those of the most strict international standards used worldwide for bathing waters. In this way, the particular dynamic processing of the water entering the swimming pool from Blanca Bay becomes important, since previous studies conducted on the water of its Principal Channel had yielded high bacteriological values which rendered it unsuitable for bathing. This work shows that in this tidal-flats system, extrapolation of results is not valid. These conditions will remain the same if other factors do not change in the tidal-flats that surround the swimming pool.

Relationship of physical factors and salinity with indicator bacteria in Bahía Blanca estuary waters, Argentina.

The relationship between the number of Escherichia coli, terrestrial and marine heterotrophic bacteria, with certain physical and chemical parameters in Bahia Blanca estuary waters, were investigated by means of a statistical analysis of multiple linear regression. The samples were taken during a period of 16 months. Although distance from the sewage outlet seems to be the factor having the greatest effect on the number of alien bacteria, the models obtained for E. coli are inappropriate to predict bacterial behaviour in this particular natural habitat, while for heterotrophic bacteria descriptive models were selected. The results of this study suggest that many factors affect bacterial population densities in this estuarine ecosystem. This should be taken into account trying to solve the problem in order to avoid progressive degradation.

Relationship of physical factors and salinity with indicator bacteria in Bahía Blanca estuary waters, Argentina

The relationship between the number of Escherichia coli, terrestrial and marine heterotrophic bacteria, with certain physical and chemical parameters in Bahia Blanca estuary waters, were investigated by means of a statistical analysis of multiple linear regression. The samples were taken during a period of 16 months. Although distance from the sewage outlet seems to be the factor having the greatest effect on the number of alien bacteria, the models obtained for E. coli are inappropriate to predict bacterial behaviour in this particular natural habitat, while for heterotrophic bacteria descriptive models were selected. The results of this study suggest that many factors affect bacterial population densities in this estuarine ecosystem. This should be taken into account trying to solve the problem in order to avoid progressive degradation.

Relationship of physical factors and salinity with indicator bacteria in Bahía Blanca estuary waters, Argentina.

The relationship between the number of Escherichia coli, terrestrial and marine heterotrophic bacteria, with certain physical and chemical parameters in Bahia Blanca estuary waters, were investigated by means of a statistical analysis of multiple linear regression. The samples were taken during a period of 16 months. Although distance from the sewage outlet seems to be the factor having the greatest effect on the number of alien bacteria, the models obtained for E. coli are inappropriate to predict bacterial behaviour in this particular natural habitat, while for heterotrophic bacteria descriptive models were selected. The results of this study suggest that many factors affect bacterial population densities in this estuarine ecosystem. This should be taken into account trying to solve the problem in order to avoid progressive degradation.

[Persistence of Escherichia coli in estuarine sediments]. / Persistencia de Escherichia coli en sedimentos estuarinos.

In order to establish the extension of fecal pollution, as well as the persistence of the indicator bacterium Escherichia coli, a bacteriological survey of the Bahía Blanca estuary sediments was done during the period August 1987-October 1988. Thirty two sampling stations were established in which sediment columns of 70 cm in length were extracted. The microbiological analysis revealed the amplitude of the area affected by industrial and sewer effluents and the viability of fecal coliforms up to 70 cm levels.

Persistencia de Escherichia coli en sedimentos estuarinos. / [Persistence of Escherichia coli in estuarine sediments]

In order to establish the extension of fecal pollution, as well as the persistence of the indicator bacterium Escherichia coli, a bacteriological survey of the Bahía Blanca estuary sediments was done during the period August 1987-October 1988. Thirty two sampling stations were established in which sediment columns of 70 cm in length were extracted. The microbiological analysis revealed the amplitude of the area affected by industrial and sewer effluents and the viability of fecal coliforms up to 70 cm levels.