Abundance and species composition of planktonic Ciliophora from the wastewater discharge zone in the Bahía Blanca Estuary, Argentina

Abstract

The specific composition and abundance variation of the ciliate community from a wastewater discharge zone in the Bahía Blanca estuary, Argentina, were studied all throughout a year, from June 1995 to May 1996. The polluted area exhibited high values of particulate organic matter and nutrients, particularly phosphates. Aloricate ciliates were represented by 15 species belonging to the genera Strombidium Claparède & Lachmann, 1859; Strombidinopsis Kent, 1881; Cyrtostrombidium Lynn & Gilron, 1993; Strobilidium Schewiakoff, 1983; Lohmmanniella Leegaard, 1915 and Tontonia Fauré-Fremiet, 1914. Tintinnids were represented by nine species belonging to the genera Tintinnidium Kent, 1881, Tintinnopsis Stein, 1867 and Codonellopsis Jörgensen, 1924. The total abundance of aloricate ciliates reached a peak of 1,800 ind. l -1 and the total abundance of tintinnids reached a peak of 9,400 ind. l -1 . Tintinnidium balechi Barría de Cao, 1981 was the most abundant ciliate in the community. Considerations on the presence and abundance of ciliates are made in relation to physicochemical and biochemical parameters.

Sewage pollution effects on mesozooplankton structure in a shallow temperate estuary

“…A high-positive significant correlation was detected between silicate and nitrate, nitrite and phosphate indicating the same pattern behaviour during the period of study. The latter agrees with the consumption behaviour of phytoplanktonic organisms (Barría de Cao et al 2003). Furthermore, the high concentration of silicate in CP probably related to the Sauce Chico river freshwater input, is in agreement with the findings of Lara and Pucci (1982), who reported an inverse relationship between silica concentration and salinity.…”

“…Unlike E. americana, A. tonsa has omnivorous habits and feeds on algae, flagellates and ciliates (Petipa 1959). In a previous study conducted at CV andB 31 stations (1995-1996), it was observed that ciliate abundance is low in winter while it increases in spring and reaches a peak in summer (Barría de Cao et al 2003). Furthermore, total abundance of aloricate ciliates correlated positively with salinity but negatively with POM in agreement with the correlations evidenced by A. tonsa, thus justifying its presence mainly at CV station.…”

“…However, the increase of phaeopigments in July in CV and B 31 stations could be due to the destruction of chlor-a for sewage's toxic substances or/and microzooplankton grazing pressure rather than mesozooplankton grazing since mesozooplankton was recorded in low abundance. The highest POM values found at CV station (reaching a peak of 7,835 μg L −1 in August) was possibly the result of both a higher freshwater discharge from the Napostá stream and sewage discharge, coinciding with the one mentioned by Barría de Cao et al (2003). An inverse relationship between POM and salinity and transparency was considered as indicator of sewage pollution in Bilbao and Urdaibai estuaries on the Basque coast (Bay of Biscay) (Uriarte and Villate 2004).…”

“…Bahía Blanca city's effluent, in particular, has been physically and chemically characterized (Lara et al 1985;Tombesi et al 2000;Hoffmeyer et al 2004) and its effects on the biota have been evaluated through bioindicators such as bacteriae (Baldini and Cabezalí 1988;Baldini et al 1999) and planktonic ciliates (Barría de Cao et al 2003) in different areas of the estuary. The composition, structure and dynamics of meso-and macrozooplankton fractions related to environmental features of Bahía Blanca estuary are well-known (Cervellini 1986(Cervellini , 2001Hoffmeyer 1983Hoffmeyer , 1994Hoffmeyer , 2004Hoffmeyer and Cervellini 2004;Sabatini 1989, among others).…”

Chitin determination on marine seston in a shallow temperate estuary (Argentina)

“…In BBE, microzooplankton is composed by Tintinnids (loricated ciliate >28 to 100 µm) and naked ciliates (BARRÍA DE CAO et al, 2003;BARRÍA DE CAO et al, 2005;. Tintinnids showed different peaks throughout the year, but their maximum abundance values occurred in summer (BARRÍA DE CAO et al, 2005).…”