Climate change effects threat life on earth especially economically poor areas. Among them is noticed the shifting of the algae species Sargassum natans and Sargassum fluitanss seaweeds from the Brazilian coast to new areas along the West African coastline. Their occurrence along the Nigerian coast and their effect on livelihood are necessary subject because of their link to coastal dwellers food security and economic activities. This study aims to evaluate the perception of coastal residents on the occurrence of Sargassum on the banks and their notion of climate change effects. 206 household heads were interviewed using a structured questionnaire over eleven areas. The coastal population knowledge about climate change and the reason of the occurrence of Sargassum species, is limited due to low education level and information access limitations. Also, the population complained about the occurrence of another specie identified as Eichhornia crassipes which disturbs fishery and boats displacements. Moreover, changes in weather conditions particularly temperature have various consequences on the respondents’ livelihood by affecting their health, welfare, feeding and incomes. The population lamented about challenges of climate change and occurrence of Sargassum fluitans affecting fishery as they have no any adaptation measures to cope with these situations.