3. Stakeholder perceptions of past changes and the present state of the Pantanal Acknowledgements: Special thanks go to the Leverhulme Trust for supporting the U.K. input to this work and in Brazil to Mato Grosso Federal University (UFMT), Pantanal Research Centre (CPP) and EMBRAPA Corumb á. 1. Longitudinal sampling transects of the Cuiabá River during the flood season 2. Isotope characteristics of different waters The transect was made from an outboard powered boat in April 2011. It started upstream of the main urban input of Cuiabá city (Rio Coxipo) and finished about 100km downstream of its confluence with the Paraguay River, at Corumba city. Water was sampled for chemistry and natural isotope abundance, and probes for DO, EC, phyco-pigments and temperature were deployed at regular intervals. Targeted sampling above and below tributary inputs also took place. Aim: to characterise the impacts of urban and floodplain river inputs on Cuiabá River chemistry and ecology. The urban impact on dissolved oxygen around Rio Coxipo (km 14) can be clearly seen, but the impact of the floodplain inputs, rich in soluble C (such as the Rio Taruma at km 163) is much larger, at least in the flood season. * Cyanobacteria dominate the phytoplankton pigment in the upper reaches, where the river is mainly confined to its channel, but further downstream in the floodplain component of the Cuiabá River, green algae dominate. This is accompanied by a very marked drop in turbidity of the water. * Cyanobacteria return to dominance in the Paraguay River, not related to anthropogenic pollution, but natural input of nutrients from floodplain in the high water phase. Conclusion: In the flood season, floodplain oxidisable carbon inputs dominate urban inputs, leading to severely depleted DO and high CO2 in the main river – a natural, not anthropogenic process. The data has the potential to be used to calibrated a river chemistry model, which could then be tested in other conditions (eg. dry season, where urban inputs will be more important drivers). Turbidity decline seems to be strongly linked to filtration by marginal floating vegetation, but also to inputs from floodplain tributaries. Conclusion: Without additional data it is not possible to make any interpretation of why the different types of water body have characteristically different isotope content. However, the results do suggest that a longer term isotope study has the potential to reveal valuable information about the sources and flow pathways of water within the river basin. During the longitudinal sampling transect of the Cuiabá river, samples for isotope analysis were taken from sites along the main stem of the Cuiabá River, from inflowing tributaries and side channels, and from lakes and flood waters. The results of the analysis are plotted in Figure 2. The data show some clear clustering in terms of their isotope content according to the type of water body from which they were sampled. Samples taken from the main stem of the river are significantly different to those sampled from lakes and flood waters, with the samples from tributaries and side channels falling somewhere between the two sets. The isotope content of precipitation can be expected to have high temporal variability and therefore there is little meaning in the single value measured during this field campaign. Aim: Improved understanding of the sources, mixing and transit times of water through the Pantanal , by interpretation of spatial and temporal variability of the δ2H and δ18O isotope content of water. Conclusion: A sound understanding of current actors and institutions, the nature of conflicts and the socio-political reality is needed to inform practical pathways towards a sustainable management of the area’s fish resource. Environmental problems affecting the Cuiabá River are the result of failures in the enforcement of a environmental regulation, as well as unresolved disputes between water user sectors and groups in different geographical locations (notably, in the plateaus, the metropolitan area of Cuiabá City and in the Pantanal floodplain). Through qualitative analysis of data from field visits, we have identified three main meta-themes that are now informing a deeper examination of socio-institutional issues: •Fishing and institutional conflicts •Public perception of environmental problems (other than fish decline) •Cuiabá City water supply and sewage treatment: institutional setting, public profiling and willingness to pay for improved water services Of all potentially relevant environmental problems identified by natural scientists, the decline of fish in the Pantanal waters was strongly perceived by almost all of the stakeholders . This decline may be closely linked to the rapid development of recreational fishing. With the decline of fish abundance, conflicts of interest emerged between different stakeholders (subsistence/ commercial fishermen; ‘eco-‘tourism; local rural communities; recreational fishermen and the urban population). Aim: Identification of key themes for socio-institutional issues. Figure 1 Water chemistry and phyco-pigment concentrations during 600 km transect down Cuiabá River into Paraguay River in April 2011. Vertical lines show input from tributaries. Figure 2 Cuiabá River sampling - March 2011. Andy Vinten 1 ,Antonio Ioris 2 , Peter Zeilhofer 3 , Eliana Dores 3 , Carlos Padovani 4 , Deborah Calheiros 3,5 , Pierre Girard 5 , Sarah Dunn 1 , Marc Stutter 1 , Julia Martin-Ortega 1 , Klaus Glenk 6 . 1 The James Hutton Institute; 2 Edinburgh University; 3 Federal University of Mato Grosso (UFMT), Cuiabá, Brazil; 4 EMBRAPA Pantanal, Corumbá, Brazil; 5 Pantanal Research Center (CPP), Cuiabá, Brazil; 6 Scottish Agricultural College, Edinburgh. Andy Vinten 1 ,Antonio Ioris 2 , Peter Zeilhofer 3 , Eliana Dores 3 , Carlos Padovani 4 , Deborah Calheiros 3,5 , Pierre Girard 5 , Sarah Dunn 1 , Marc Stutter 1 , Julia Martin-Ortega 1 , Klaus Glenk 6 . 1 The James Hutton Institute; 2 Edinburgh University; 3 Federal University of Mato Grosso (UFMT), Cuiabá, Brazil; 4 EMBRAPA Pantanal, Corumbá, Brazil; 5 Pantanal Research Center (CPP), Cuiabá, Brazil; 6 Scottish Agricultural College, Edinburgh. The Pantanal Network: sharing experience to develop robust approaches to catchment management in the Cuiabá River, Brazil Andy Vinten 1 ,Antonio Ioris 2 , Peter Zeilhofer 3 , Eliana Dores 3 , Carlos Padovani 4 , Deborah Calheiros 3,5 , Pierre Girard 5 , Sarah Dunn 1 , Marc Stutter 1 , Julia Martin-Ortega 1 , Klaus Glenk 6 . 1 The James Hutton Institute; 2 Edinburgh University; 3 Federal University of Mato Grosso (UFMT), Cuiabá, Brazil; 4 EMBRAPA Pantanal, Corumbá, Brazil; 5 Pantanal Research Center (CPP), Cuiabá, Brazil; 6 Scottish Agricultural College, Edinburgh.