Lac Alaotra is Madagascar's largest lake and a recognized wetland of international importance under the Ramsar Convention. It supports several Critically Endangered species, including the Alaotran gentle lemur Hapalemur alaotrensis. A principal threat facing the remaining Alaotran wetland is anthropogenic burning of the vegetation during the dry season; a practice now officially banned. A number of reasons have been given to explain this but to date no attempt has been made to investigate the principal motivations for the burning. We present the results of semi-structured interviews (n = 27) and questionnaires (n = 122) in a lakeside town. Seventy-eight percent of interviewees stated wetland burning was performed only or mainly to gather an introduced fish, the Asian snakehead Channa maculata, which buries into the underlying substrate during the dry season. Sixty-eight percent of questionnaire respondents provided a similar explanation. These data provide valuable insights into the reasons for the ongoing burning and should inform the management actions that are required to protect this globally important wetland.