Freshwater ecosystems are under increasing pressure. From a value perspective, this pressure is closely related to a too narrow definition of nature’s values in decision-making. Assessing plural values that encompass not only economic factors, but a variety of different value dimensions, such as socio-cultural and intrinsic values, is imperative to achieve transformative change. Nevertheless, assessment and consideration of multiple values is still scarce. To promote a perspective of plural values in environmental decision-making, we assessed intrinsic, instrumental, and relational values that people hold in a case study at the Lac Saint-Pierre, Quebec, where socio-environmental conflicts occur. We conducted semi-structured interviews with local stakeholders and oriented our analysis along two conceptual frameworks: the IPBES (Intergovernmental Panel on Biodiversity and Ecosystem Services) values framework, and the Ojeda et.al. 2022 proposition on reciprocal contributions between humans and nature. Moreover, we identified narratives about human-nature relationships, and implications for decision-making that come along with these prevailing worldviews. Our results show a strong discourse of human-nature dichotomy, accentuating the perceived opposition of instrumental and intrinsic values. This opposition comes along with narratives of fragility and wilderness which has to be protected from human influence. Relational values were strong in participants discourses, but not represented in actual decision-making processes. Our findings suggest that the identified relational values and related concepts, such as environmental justice and equity concerns, need to be emphasized in policy-making to ensure an inclusive and sustainable management of aquatic ecosystems.