Small indigenous fishes (SIF) play a crucial role in supporting the livelihoods and nutritional security of the rural population in Southern Asia. However, their abundance and diversity are under threat due to overexploitation and profitable extensive aquaculture, resulting in a sharp decline, particularly in India. Unfortunately, conservation strategies for SIF have received little attention from researchers, making it imperative to understand stakeholders’ decision-making processes to develop effective conservation strategies. This article aims to quantitatively identify the factors that influence fishermen’s intention to participate in and pay for SIF conservation efforts. The study utilizes questionnaire-based survey data from 100 households engaged in local fisheries in the rural Indian Sundarbans. To gain critical insight into fishermen’s decision processes, a bivariate logistic Generalized Additive Model is employed, focusing on willingness-to-participate and willingness-to-pay for SIF conservation. The study’s results indicate that several factors significantly influence fishermen’s willingness-to-participate in conservation efforts. These include Literacy, Conservation awareness, and Occupation. On the other hand, Conservation awareness and Household income are identified as significant determinants of fishermen’s willingness-to-pay for SIF conservation initiatives. One intriguing finding of the research is the identification of a nonlinear response-age curve for both willingness-to-participate and willingness-to-pay, as well as their interaction. Notably, the 45-50 years old age group emerged as the most likely implementers of small indigenous fish conservation strategies, suggesting that targeting this age group in conservation programs could yield positive outcomes. The study underscores the importance of various conservation strategies to bolster SIF preservation in the region. Recommendations include increasing and extending conservation awareness programs, specifically targeting suitable age-group individuals with appropriate education, household income, and occupation. These strategies are vital for formulating effective conservation guidelines that align with the specific needs and characteristics of the region. In conclusion, this research sheds light on the factors influencing fishermen’s participation and willingness to financially support the conservation of small indigenous fish in the rural Indian Sundarbans. The findings contribute valuable insights for policymakers, conservationists, and stakeholders, emphasizing the urgency of sustainable measures to safeguard SIF populations and ensure the continued livelihoods and nutritional security of the local communities.@en