Pilcomayo River Fishery. Status of the Sabalo Fishery and the Potential Impact of Dam Construction

This project, undertaken in conjunction with the Overseas Development Administration (UK) through the Mission Britanica aimed to assess the status of the fishery for the sabalo (Prochilodus platensis) in Bolivia, one of the largest suppliers of fish for the country, and the potential of dam construction.  The ODA has a past association with the Centro de Desarrollo Pesquero in the Rio Pilcomayo with this project forming a response to concern expressed by the CDP over the future of the fishery as a result of plans being formulated to put a dam across the Pilcomayo and otherwise control and utilize the water resources of the river.

On site monitoring and assessment was carried out during June 1993 with assistance of PROVISA (Pryecto Villamontes Sachapera) who were responsible for the planning programme and feasibility study for the construction of the dam.

Analysis of the fishery utilised data on both the catchment and the fishery in order to provide recommendations for the limitation of future development of the fishery.

Assessment of the impacts of the PROVIS project took into account a number of aspects.  These included:

-the effects of the proposed dam on the migration of adult fish, assessing the implications of the use of fish ladders or a trap;

-the effect on the downstream movement of alevins and young; and

-the impact of the hydro-dynamics created.  These include changing water levels and flows created by the dam, as well as changes in water quality.