REPORT OF THE WORKING GROUP ON MAJOR THREATS AND CONSERVATION

IntroductionThe species of the genus Sotalia inhabit river and lakesystems of Amazonia, the lower Orinoco River, andcoastal marine waters from Nicaragua to southern Brazil(Borobia et al., 1991; da Silva and Best, 1994; 1996; Carrand Bonde 2000; Flores and da Silva, 2009). Freshwaterand marine animals can be differentiated based onskeletal morphology (Monteiro Filho et al., 2002).Recently they were demonstrated to be separate species,with S. fluviatilis being the riverine species in theAmazon and S. guianensis being found in marine andestuarine environments (Cunha et al., 2005; Caballero etal., 2007). The identity of the animals found in theOrinoco system remains unclear (see Sole-Cava et al.2010, this volume). Both species are believed to be locallyabundant, although numbers reported for some areas(such as Guanabara Bay, Rio de Janeiro) seem to havedeclined (Santos et al., 2010, this volume; Azevedo etal., 2008). Common names for the riverine species S.fluviatilis include ‘ tucuxi’ in Brazil or ‘ bufeo negro ’ in othercountries, while the marine species S. guianensis is called‘boto-cinza’, or simply ‘boto’ or ‘golfinho’ in Brazil. Theproposed English common name for S. guianensis is‘Guiana dolphin’ (Flores et al., 2010 this volume).The freshwater and near-shore marine distribution meansthat both Sotalia species are vulnerable to the effects ofanthropogenic activities, including water developmentprojects, chemical pollution, noise, as well as by-catch.The Scientific Committee of the International WhalingCommission (IWC) urged in 1994 that steps should betaken by member states to reduce incidental mortality ofSotalia, while at the same time establishing better systemsof recording and monitoring take levels (IWC, 1995).A particular concern has been expressed for the statusof mangrove forests, which are threatened in many areasby pollution and coastal development. Several Guianadolphin populations probably depend to a considerableextent on the productivity derived from mangroveecosystems (Zanelatto, 2001) and may be particularlyvulnerable as the species appears to occur in a series ofsmall resident populations along the Brazilian coast ( e.g.Geise and Borobia, 1988; Santos et al. 2001; Rossi-Santoset al., 2007; Nery et al., 2008a).This report presents the discussions of the group taskedwith covering Major Threats and Conservation at the‘Workshop on Research and Conservation of the genusSotalia’ held in Armacao dos Buzios, Rio de Janeiro,Brazil, 19-23 June 2006. It is intended as a compilationof information supplied by workshop participants andfrom a literature review. This report is organized by typeof threats: documented and potential. Participants alsoreviewed aspects of regulations and legislation in thedifferent countries, which are included in this report.Documented ThreatsF