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Leal A.L.,SITEL | Leal A.L.,Laboratory of Molecular Biology | Dalzochio M.S.,Laboratory of Ecology and Conservation of Aquatic Ecosystems | Flores T.S.,SITEL | And 3 more authors.
Journal of Industrial Microbiology and Biotechnology

Microbiological analysis of activated sludge is an important tool for monitoring wastewater treatment plants (WWTP). The utilization of the sludge biotic index (SBI) provides helpful information in examining the quality of biological treatment process and has been tested for several different systems. Although its utilization has been increasing, it is still not widespread, especially in Brazil. Also, its applicability has been considered limited for some particular systems. Thus, it becomes important to evaluate the relations among operational and biological parameters of each WWTP in order to characterize the system and its variations. In this work, microscopic analysis were performed once a week for 1 year (n = 54) and the results were compared to the physicochemical, operational parameters and efficiency of the plant along the period. The four seasons were comprised and analyzed, as we cannot neglect the influence of environmental changes in this subtropical region. Not only had we found a strong influence of the evaluated parameters on the structure of the biological community but there is also a good correspondence of SBI with the performance of the WWTP. More importantly, including microscopic analysis in the operational routine made it possible to notice even the slightest changes in the biological community that were not enough to diminish the SBI classification of the sludge, but were satisfactorily informative to show in advance to operators when to take corrective actions about an increase of COD and BOD in the influent and when it was necessary to discard the exceeding sludge. Source

Crippa L.B.,Laboratory of Ecology and Conservation of Aquatic Ecosystems | Stenert C.,Laboratory of Ecology and Conservation of Aquatic Ecosystems | Maltchik L.,Laboratory of Ecology and Conservation of Aquatic Ecosystems
Ocean and Coastal Management

This study assessed the influence of an artificial sandbar opening on the macroinvertebrate richness, abundance and composition of the Lagoa do Peixe floodplains in the only Ramsar site in southern Brazil. The Lagoa do Peixe has its connection with the sea artificially opened every year at the end of winter. However, this management intervention has been carried out without the evaluation of the impact of this opening in the aquatic biodiversity. Six samplings were carried out over two years (from March 2008 to October 2009) which encompassed two artificial sandbar openings. The mean richness and abundance were lower in the floodplain sites influenced by the artificial sandbar opening (opened wetlands) than in the floodplain sites not influenced by this event (natural wetlands). Water salinity was higher in opened wetlands than in natural wetlands during the open sandbar samplings. The richness was negatively associated with water salinity, and the abundance was positively associated with hydroperiod, and negatively associated with conductivity. The composition of macroinvertebrate taxa was different between opened and natural wetlands. Our results suggest that artificial sandbar openings have a negative impact on freshwater macroinvertebrate communities in southern Brazil floodplain wetlands. Hydrologic variation and increase of salinity related to this management may be the main factors of the change in the richness, abundance and composition in opened wetlands. We concluded that the artificial sandbar opening should be carefully re-analysed or forbidden, since this management practice may be jeopardizing the aquatic macroinvertebrate community in a National Park and Ramsar site, where the biodiversity conservation is a priority and protected by Brazilian laws. © 2012 Elsevier Ltd. Source

Maltchik L.,Laboratory of Ecology and Conservation of Aquatic Ecosystems | Dalzochio M.S.,Laboratory of Ecology and Conservation of Aquatic Ecosystems | Stenert C.,Laboratory of Ecology and Conservation of Aquatic Ecosystems | Rolon A.S.,Laboratory of Ecology and Conservation of Aquatic Ecosystems
Revista de Biologia Tropical

The selection of priority areas is an enormous challenge for biodiversity conservation. Some bio-geographic methods have been used to identify the priority areas to conservation, and panbiogeography is one of them. This study aimed at the utilization of panbiogeographic tools, to identify the distribution patterns of aquatic insect genera, in wetland systems of an extensive area in the Neotropical region (~280 OOOkm2), and to compare the distribution of the biogeographic units identified by the aquatic insects, with the conservation units of Southern Brazil. We analyzed the distribution pattem of 82 genera distributed in four orders of aquatic insects (Diptera, Odonata, Ephemeroptera and Trichoptera) in Southern Brazil wetlands. Therefore, 32 biogeographic nodes corresponded to the priority areas for conservation of the aquatic insect diversity. Among this total, 13 were located in the Atlantic Rainforest, 16 in the Pampa and three amongst both biomes. The distribution of nodes showed that only 15% of the dispersion centers of insects were inserted in conservation units. The four priority areas pointed by node cluster criterion must be considered in further inclusions of areas for biodiversity conservation in Southern Brazil wetlands, since such areas present species from different ancestral biota. The inclusion of such areas into the conservation units would be a strong way to conserve the aquatic biodiversity in this region. Rev. Biol. Trop. 60 (1): 273-289. Epub 2012 March 01. Source

Dalzochio M.S.,Laboratory of Ecology and Conservation of Aquatic Ecosystems | Baldin R.,Laboratory of Ecology and Conservation of Aquatic Ecosystems | Stenert C.,Laboratory of Ecology and Conservation of Aquatic Ecosystems | Maltchik L.,Laboratory of Ecology and Conservation of Aquatic Ecosystems
Basic and Applied Ecology

The use of agrochemicals, water management and intense mechanization is compromising species diversity in rice fields. Organic agriculture has been proposed as a way to reduce the pressure on biodiversity in agricultural landscapes. Therefore, the following hypotheses were tested: (1) Taxonomic richness and abundance of macroinvertebrates are lower in rice fields than in natural ponds; (2) Conventional rice crops decrease taxonomic richness and abundance of macroinvertebrates compared with organic crops; (3) Taxonomic macroinvertebrate composition in organic rice crops is more similar to the composition in natural ponds than conventional fields; and (4) A reduction of taxonomic richness, abundance as well as a modified composition during soil preparation and the initial growth phases of the rice cultivating cycle were expected. To test these hypotheses, four natural ponds, four organic and four conventional rice fields were selected in southern Brazil. In each area, six collections were carried out over the rice cultivation cycle (August 2010 to August 2011). A total of 25,449 individuals from 73 different taxa were sampled. The richness and abundance were higher in ponds than in rice crops in the anterior and posterior off-season and in the soil preparation periods. However, organic and conventional rice fields showed similar taxonomic richness and abundance. Although the taxonomic composition differed only between rice crops and ponds, the presence of many taxa that only occur in organic crops and ponds indicates that organic management favors the establishment of some pond macroinvertebrate taxa in rice agroecosystems, mainly predators. Our results should be seen as an incentive for more sustainable production with less impact on the environment. Der Einsatz von Agrochemikalien, Bewässerungsmanagement und intensive Mechanisierung beeinträchtigen die Artendiversität in Reisfeldern. Biologische Landwirtschaft wurde als eine Möglichkeit vorgeschlagen, den Druck auf die Biodiversität in der Agrarlandschaft zu mindern. Wir überprüften deshalb die folgenden Hypothesen: (1) Taxonomische Diversität und die Abundanz von Makroinvertebraten sind auf Reisfeldern geringer als in natürlichen Tümpeln. (2) Konventioneller Reisanbau verringert die Anzahl der Taxa und die Abundanz der Makroinvertebraten im Vergleich zu biologischem Anbau. (3) Die taxonomische Zusammensetzung der Makroinvertebraten auf biologischen Reisfeldern ähnelt der von natürlichen Tümpeln stärker als der von konventionellen Feldern. (4) Eine Reduktion der Taxonzahlen, Abundanz sowie eine veränderte Zusammensetzung wurden für die Zeit der Feldvorbereitung und die frühen Wachstumsphasen erwartet. Wir untersuchten jeweils vier natürliche Tümpel sowie biologische und konventionelle Reisfelder in Süd-Brasilien. An jedem Standort wurden sechs Probenahmen im Laufe des Reis-Anbauzyklus' durchgeführt (August 2010 bis August 2011). Insgesamt wurden 25,449 Individuen aus 73 Taxa gesammelt. Während der Ruhephase vor und nach dem Anbau sowie während der Bodenvorbereitungsphase waren taxonomische Diversität und Abundanz in den Tümpeln höher als auf den Reisfeldern. Biologische und konventionelle Reisfelder zeigten ähnliche taxonomische Diversität und Abundanz. Auch wenn die taxonomische Zusammensetzung sich nur zwischen Tümpeln und Reisfeldern unterschied, zeigte das Auftreten von Taxa, die nur in Tümpeln und auf biologischen Feldern nachgewiesen wurden, dass biologische Bewirtschaftung die Ansiedlung von einigen Tümpel bewohnenden Makroinvertebraten (hauptsächlich Prädatoren) auf Reisfeldern begünstigt. Unsere Ergebnisse sollten als ein Anreiz zu mehr nachhaltiger Produktion mit weniger Auswirkungen auf die Umwelt gesehen werden. © 2015 Gesellschaft für Ökologie. Source

Stenert C.,Laboratory of Ecology and Conservation of Aquatic Ecosystems | Bacca R.C.,Laboratory of Ecology and Conservation of Aquatic Ecosystems | Moraes A.B.,Laboratory of Ecology and Conservation of Aquatic Ecosystems | De Vila A.C.,Laboratory of Ecology and Conservation of Aquatic Ecosystems | Maltchik L.,Laboratory of Ecology and Conservation of Aquatic Ecosystems
Marine and Freshwater Research

Exotic pine invasion influences native wetland assemblages by changing environmental conditions such as hydrological regime and physicochemical characteristics. The expansion of cultivated pine has been a concern in southern Brazil and its impacts on aquatic biodiversity are poorly known. We tested the hypotheses that: (1) pine invasion decreases aquatic macroinvertebrate richness and abundance, modifying composition and macroinvertebrate functional feeding groups in ponds; and (2) -diversity between natural and pine ponds is determined mainly by species nestedness. Five ponds in native grassland and five in a pine-planted matrix were sampled seven times from 2007 to 2009. The pine ponds had reduced macroinvertebrate richness and abundance, and different taxa and functional feeding groups. Comparing ponds in natural and cultivated pine areas, -diversity as determined by nestedness did not differ from the value resulting from the turnover. Reduction of surface in ponds in pine areas may be one of the main causes for the lower macroinvertebrate richness and abundance because many taxa do not have adaptations to tolerate or escape the dry phase. Our results suggest that pine invasion has a negative impact on macroinvertebrate structure in southern Brazil coastal ponds. © CSIRO 2012. Source

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