This study aims to assess the household diversification of coastal fishing on coastal communities' welfare in the District of Kabila Bone, Bolango District, for five months, from August 2019 - November 2019. Samples of the coastal community of 200 people, making do with a survey method. The data collected are primary data and secondary data using observation, interview techniques, documentation techniques. The model developed from the relevant theory, then tested on a model using the Structural Equation Model (SEM) based on SMART PLUS. The analysis of business diversification models suggests that the utilization of environmental services does not affect coastal communities' welfare.

Keywords: diversification; SEM-PLS; welfare; environmental sustainability, Tomini Bay