Bacterioplancton in different tides of the Perequê tidal creek, Pontal do Sul, Paraná, Brazil

Abstract

The influence of tidal phase on bacteria abundance in surface waters was studied in five stations along the Perequê tidal creek (Paraná State, Brazil), at spring and neap low and high tides in July 1999. The stations were located from the mouth (St.1) to the creek's head (St. 5). The following parameters were analyzed: salinity, temperature, pH, dissolved oxygen, total carbon dioxide, seston, particulate organic matter, pluviosity, chlorophyll "a", total heterotrophic bacteria, bacterial biomass, cultivable heterotrophic aerobic halophilic and halophobic bacteria, total coliforms and Escherichia coli. The results showed that the highest values of salinity, pH and dissolved oxygen at stations 1 to 4 were registered during the spring high tide. The amount of total heterotrophic bacteria was directly proportional to seston and chlorophyl values at stations 2 and 3 during low tide of July 28, and at station 5 during high tide of the same day. The values of cultivable heterotrophic aerobic halophilic and halophobic bacteria, total coliforms and E. coli, were directly correlated with particulate organic matter and pluviosity. The largest of these values were registered during the neap low tide of July 6. This period was characterized by high precipitation, which may have influenced the bacterial number variation. During the neap high tide and, sporadically, during the neap and spring low tide, the lowest values of total heterotrophic bacteria and bacterial biomass were registered. The results showed great influence of the tide on the bacteria at stations 1 to 4, but not at station 5.

Coliform density in oyster culture waters and its relationship with environmental factors

“…This occurred possibly because of the high rainfall recorded in the region, and also due to the increase of tourists in the region. Kolm & Andretta (2003) also observed the occurrence of higher densities of bacteria in the water of Perequê´s stream, in Pontal do Sul, PR, in months with higher precipitation, which, however, for that region was the month of July.…”

“…Galvão et al (2006), when studying the microbiological quality of water and mussel cultivation in Ubatuba, SP, Brazil, found evidence of microbiological contamination in the water and the mussels, but these values had no relationships with pH. Variations in pH may be related to the tides, and Kolm & Andretta (2003) reported that, during high tides, the change in pH was significantly higher than during low tides.…”

“…This is possibly due to the constant water flow during the tidal cycle in the Cooperostra-growing area. Kolm & Andretta (2003) studied the bacterial contamination of Perequê´s stream, in Pontal do Sul, PR, Brazil, and found a direct relationship between tides and coliform concentration, with highest values during low tide in July. However, this period was characterized by high precipitation, which may also have influenced the concentration.…”

Evaluation of the water quality of tidal creeks of Pontal do Paraná, Paraná, Brazil

“…The significant intrusion of saline waters from the continental shelf was only observed in the Perequê tidal creek. Kolm and Andretta (2003) studied the salinity of this tidal creek and observed high marine influence along significant part of its extension. Part of the Perequê's bed was artificially altered in the past and ended in the DNOS channel dredged artificially in the 1950´s decade.…”

“…The Perequê tidal creek, 2.6 km long, is typically meandrous with outlet in the DNOS Channel, close to the entrance of Paranaguá Bay. Part of its extension divides Pontal do Sul in two sections (Kolm and Andretta, 2003). Along its margins, banks of Spartina alterniflora and mangroves are found.…”