Ecological and toxicological responses in a multistressor scenario: Are monitoring programs showing the stressors or just showing stress? A case study in Brazil Julio C. López-Doval a, ⁎, Sergio Tadeu Meirelles a , Sheila Cardoso-Silva b , Viviane Moschini-Carlos b , Marcelo Pompêo a a Institute of Biosciences, Department of Ecology, University of São Paulo, do Matão Str., Travessa 14, 321, Butantã, 05508-090 São Paulo, SP, Brazil b São Paulo State University — UNESP “Júlio de Mesquita Filho”, Environmental Sciences Program, 3 de Março Avenue n. 511, PO Box: 18087-180, Sorocaba, SP, Brazil HIGHLIGHTS • Data on water quality of urban reservoirs has been statistically analyzed. • Analysis was focused on community and bioassay responses and stressors. • Data showed spatial and temporal lacks and non-compliances for some parameters. • Bioassays and planktonic community demonstrated impairments in biota. • Physical and chemical data compiled do not completely explain biological responses. abstract article info Article history: Received 25 March 2015 Received in revised form 19 May 2015 Accepted 20 May 2015 Available online xxxx Editor: D. Barcelo Keywords: Freshwater monitoring Toxic units Chemometrics Urban reservoirs Tropical reservoirs Brazil The Metropolitan Region of São Paulo (MRSP) is located in the Brazilian State of São Paulo and reservoirs in this region are vital for water supply and energy production. Changes in economic, social, and demographic trends produced pollution of water bodies, decreasing water quality for human uses and affecting freshwater popula- tions. The presence of emerging pollutants, classical priority substances, nutrient excess and the interaction with tropical-climate conditions require periodic reviews of water policies and monitoring programs in order to detect and manage these threats in a global change scenario. The objective of this work is to determine wheth- er the monitoring program of the São Paulo's Environmental Agency, is sufficient to explain the toxicological and biological responses observed in organisms in reservoirs of the MRSP, and whether it can identify the possible agents causing these responses. For that, we used publicly available data on water quality compiled by this agen- cy in their routine monitoring program. A general overview of these data and a chemometric approach to analyze the responses of biotic indexes and toxicological bioassays, as a function of the physical and chemical parameters monitored, were performed. Data compiled showed temporal and geographical information gaps on variables measured. Toxicological responses have been observed in the reservoirs of the MRSP, together with a high inci- dence of impairments of the zooplankton community. This demonstrates the presence of stressors that affect the viability of organisms and populations. The statistical approach showed that the data compiled by the environ- mental agency are insufficient to identify and explain the factors causing the observed ecotoxicological responses and impairments in the zooplankton community, and are therefore insufficient to identify clear cause–effect re- lationships. Stressors different from those analyzed could be responsible for the observed responses. © 2015 Elsevier B.V. All rights reserved. 1. Introduction Preservation of the structure and function in freshwater ecosystems is needed to ensure economic, cultural, and recreational benefits for humans (Turner and Daily, 2008). For this reason, the identification and control of potential threats that might impair freshwater ecosys- tems are required in order to ensure consistent quality of the water supply. Chemical pollution in water bodies is a well-known factor that de- creases water quality for human uses and can affect freshwater popula- tions in terms of their abundance, distribution, and interactions with other organisms and the environment, consequently causing effects on the ecosystem (Brack et al., 2005). Other environmental factors Science of the Total Environment xxx (2015) xxx–xxx ⁎ Corresponding author. E-mail address: jclopezdoval@usp.br (J.C. López-Doval). STOTEN-17823; No of Pages 11 http://dx.doi.org/10.1016/j.scitotenv.2015.05.085 0048-9697/© 2015 Elsevier B.V. All rights reserved. Contents lists available at ScienceDirect Science of the Total Environment journal homepage: www.elsevier.com/locate/scitotenv Please cite this article as: López-Doval, J.C., et al., Ecological and toxicological responses in a multistressor scenario: Are monitoring programs showing the stressors or just showing ..., Sci Total Environ (2015), http://dx.doi.org/10.1016/j.scitotenv.2015.05.085