will require to be undertaken over a period of at least one, and ideally two, complete annual cycles. Any study of shorter duration is likely to be superficial and of limited value in detecting the true environmental impact.
By definition, drainage in the Bañados will have an environmental impact. What needs to be determined is not what that impact is, but rather whether the true economic and social cost of that impact can be offset by the investment whose impact is being studied. To determine whether this is indeed the case, attention needs to be focused not only upon the environmental impact of drainage investment, but upon the precise sum required to carry out the drainage, the effectiveness of that drainage, the precise return upon that investment, the distribution of benefits from that investment to the communities which currently use the resources, and the net impact upon the national economy. Unfortunately, we were unable to obtain copies of the detailed proposals for the Bañados, and it is therefore not possible at this stage to say whether such detailed analyses have been carried out. However, it is clear that the full value of the wetland resources of the Bañados, and their interaction with the economic activities in the region, is considerable. We therefore believe that prior to any further investment in the Bañados, a detailed ecological and hydrological study of the resources should be carried out in order to determine the full range and full value of the functions which these wetlands provide. These functions will range from flood control to provision of water supply, fisheries support, and species conservation. The impact upon these functions, and the economic consequences of their loss as a result of drainage, should be assessed and this net loss to the economy should be compared with the net benefit as a result of the investment. In this context, specific consideration needs to be given not only to the yield in terms of rice production that would be generated but to the investments (fuel, infrastructure, and running costs) which are required to achieve the drainage proposed and to exploit the drained land.
Other neighbouring wetland areas
In addition to the areas included within the Ramsar site, several other wetland areas in the region are of international interest. Most notable among these is the Laguna de Rocha which is widely regarded as being one of the most important sites in Latin America for migratory waterbirds. More information is needed on this and other similar sites in order to identify their precise management requirements. This is of particular importance as effective protection of these sites could be an appropriate compensatory measure for loss of some of the wetland area within the Bañados del Este.
i) Despite the considerable national and international concern for the Bañados del Este, there is today a rising willingness on the part of the government of Uruguay to address these problems and to identify solutions. This effort should be supported by the Ramsar Convention and particular efforts made to ensure that solutions are pursued through an integrated interdisciplinary approach, and through an inter-institutional consensus which involves both government and non-governmental institutions.
ii) It is clear that large areas of the original site designated under the Ramsar Convention have been converted to agriculture and can no longer be considered as wetlands. While it is extremely regrettable that this occurred without a full environmental impact assessment, the limits of the Ramsar site now need to be reviewed and those areas which are clearly under intensive agricultural production or intensive grazing as of 1 January 1989 should be excluded. Other areas vhere agricultural production and grazing are extensive should be considered for inclusion in a buffer zone surrounding sites of highest ecological and hydrological value. These sites should be retained on the Ramsar List.
iii) In order to identify such sites, a detailed analysis of the available information on the fauna and flora o