As the Don Sahong dam will block the main channel passable year-round by migrating fish, the downstream fish population is feared to be threatened. Local communities near the dam site and downstream in Cambodia highly depend on both subsistence and commercial fishing. The project hereby undermines food security throughout the Mekong River Basin. No transboundary impact assessments have been conducted.

Additionally, Mega First Corporation Berhad failed to properly inform affected people. Local communities are reported to have received misleading information, while communities downstream in Cambodia have not received any information from the project's developer.

The Don Sahong dam is expected to significantly reduce the amount of migratory fish moving between Laos, Cambodia, Thailand and Vietnam. This forms a huge threat to the food security of millions of people living both up- and downstream of the dam project. The human rights of millions are under pressure, such as the right to life and the right to food. Local residents are already found to be malnourished, and fish is their most important source of protein.

In October 2014, a national and international coalition of NGO's, including International Rivers, filed a complaint with the Human Rights Commission of Malaysia (SUHAKAM), urging the commission to ensure Malaysian company Mega First complies with international human rights standards. Among these are the right to life and livelihood and the obligation to inform affected communities. After initially accepting the complaint, SUHAKAM unfortunately concluded it lacked the mandate for foreign investment projects of Malaysian companies. However, SUHAKAM did recommend Mega First to respect the human rights of people affected by the companies projects.

In February 2016, the United Nations Human Rights Council notified the governments of Laos and Malaysia, as well as the Malaysian company Mega First, of their concerns on alleged human rights violations regarding the Don Sahong dam project. The Council found "[the] right to an adequate standard of living, including the rights to food and adequate housing, the right to the highest standard of physical and mental health, cultural rights and the rights to information and participation appear to be at particular risk, as do the rights of indigenous peoples living in the area". The Council also notedthe lack of regional/international cooperation through the MRC and the lack of proper information being shared with local residents by both the government and the company. Non of the summoned parties have yet responded.

The area expected to be affected by the Don Sahong dam is inhabited by many indigenous people and ethnic minorities. Among them are the Kuy (Kuoy) in Cambodia. As is typical for many indigenous peoples, the Kuy have a strong cultural and traditional relationship with their land and the Mekong river, which is central for their livelihood. Indigenous people are protected by international law, such as ILO Convention 169. Free, prior and informed consent is required for any project to be developed on indigenous territory. Non of the indigenous people about to be affected by the dam has been consulted.

The Hou Sahong Channel, in which the Don Sahong dam will be built, is a vital corridor for migrating fish. Over a 100 species are reported to migrate through this channel, of which some are known to travel as far as Vietnam. Blocking the channel threatens migration, feeding and breeding patterns of a huge number of fish and therefore the unique aquatic biodiversity.

Also, the dam threatens the highly endangered Irrawaddy dophin, of which only 85 remain in the Mekong River. A core habitat of these dolphins is located just one kilometre downstream of the dam site. Construction may disturb the dolphins and the dam's impact on fish migration may subduct their only food source. The Don Sahong dam therefore increases the risk of the species' extinction.