International Journal of Environmental Research and Public Health
The aquaculture sector has experienced fast growth as a result of livelihood diversification
initiatives among small-scale farmers in Tanzania. Regrettably, the dynamics of harmful algal blooms
(HABs) have been overlooked despite the noticeable forcing of climate variability, the interaction
between social-economic activities, and domestic water supply reservoirs. This study aimed at
surveying the occurrence, experiences, and perceptions of HABs in aquaculture systems from
stakeholders in the Ngerengere catchment, Morogoro, Tanzania. A cross-sectional survey focus
group discussion (FDG), key informant interviews, and anecdotal observation were adopted. A
convenient and purposive sample population was drawn from pond owners, registered water users,
and government officials in the catchment. For data analysis, descriptive statistics and constant
comparison were performed. Most respondents (95%) were able to recognize the image of blooms
displayed. Approximately 70% of the respondents agreed that water quality has deteriorated over
time, and blooms occur during the dry season. Further, 60% of the respondents agreed that water
pollution is a serious problem attributed to sources other than industrial discharge. There was
no consensus regarding the health impacts associated with HABs. Raising awareness on HABs is
of paramount importance as it will provide the basis for the development of HABs management
framework and health risk assessment.