Nam Theun 2 is the largest neo-reservoir in Lao PDR that was impounded to produce electricity. The objective of this study was to assess the input of the offshore zone to the total fish production. Hydroacoustics in areas > 5 m deep were sampled during the cold-dry season for 2 consecutive years. Results showed low fish densities (200–300 ind. ha⁻¹), low biomass ( < 1 kg ha⁻¹) and fish of small sizes (approximately 6 cm) in deep zones. Fish stock in the pelagic zone was concentrated between 2 and 13 m depth. The low colonization by fish was corroborated by the small catches achieved by experimental fishing in this part of the reservoir. This study has highlighted the limited contribution of the pelagic zone of a large neo-reservoir to fish production (low density, low biomass and few commercial species) when the reservoir was at its maximal water level. This study suggests that future management actions should mainly focus on the littoral zone.

中文翻译：

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老挝的大型热带水库中近海区域对渔业的投入少

Nam Theun 2是老挝最大的新水库，被蓄意发电。这项研究的目的是评估近海区域对鱼类总产量的投入。在冷干季节连续两年采样深度大于5 m的区域的水声。结果显示鱼密度低（200–300 ind。ha ^-1），生物量低（<1 kg ha ^-1）和深区域的小尺寸（约6厘米）鱼。中上层带的鱼类种群集中在2至13 m的深度之间。在水库的这一部分中，通过实验性捕捞获得的小渔获证实了鱼类的低殖民化。这项研究强调了当水库处于最高水位时，大型新水库的中上层带对鱼类生产的贡献有限（低密度，低生物量和少量商业物种）。这项研究表明，未来的管理措施应主要集中在沿海地区。