Report of the FAO/TCF Workshop on Fish Passage Design at Cross-River Obstacles: Experiences from Different Countries, with Potential Relevance to Mongolia

The workshop “Fish passage design at cross-river obstacles – experiences from different countries, with potential relevance to Mongolia” was jointly organized by FAO and the Taimen Conservation Fund (TCF) of Mongolia and held in Mongolia in April 2014. Workshop participants included representatives from the Ministry of Nature and Green Development of Mongolia, the Egiin Gol Hydro Power Plant Project Unit (EGHPPPU), the Dorgon hydropower station, the Mongolian Mining Corporation, the National Water Association, civil society and the TCF. Workshop participants presented two country reports on the status of fish passage development, research and construction in Mongolia, and on the biology and behaviour of the most important fish species to be considered in planning fish passage facilities in Mongolia, and in particular in the Eg River. The resource persons presented knowledge on different fish passage issues from both the biological and the engineering perspectives. Although the known facts are mainly derived from studies in North America and Europe, the basic aspects can serve as “food for thought” also in other regions, including Mongolia. Information provided and designs presented should, however, under no circumstances just be copied but have to be adapted to local conditions (taking into due consideration the species present) while respecting the important basic design criteria which are valid for all passes of the same type at all locations, whether in Europe, North America or Asia. As regards the planned Eg River hydropower plant, the workshop did not have a unanimous view concerning the need for, and the usefulness and the environmental impacts of, the planned dam construction. However, all workshop participants unanimously agreed that, should the dam on the Eg River be constructed, a fish passage system would be needed to mitigate the blocked upstream and downstream passage for maintaining genetic exchange between fish in the Eg and Selenge Rivers. The workshop agreed that trap-andtransport for both upstream and downstream fish passage, with the option of later modifications, would be the only viable solution for this Eg River power plant. However, the resource persons clearly held that based on their assessment during the field visit and the additional information provided during the classroom sessions – from a fish ecological, biodiversity and fisheries point of view – the dam must not be constructed at the planned location because it would inflict irreversible damage to the aquatic ecosystem. In fact, the excellent ecological status of the Eg River just upstream of the confluence with the Selenge River (and also further upstream in the watershed) calls for the preservation of the given morphological and hydrological characteristics. Alternatives should be sought as regards either the location of the dam (i.e. consider to construct one dam or several smaller dams on one or several other rivers that are less important for taimen) or the type of energy produced (solar or wind). Furthermore, the resource persons held that, most importantly, the workshop must not be seen as encouragement to construct new dams solely because the principles of the design and construction of fish passage facilities are known.