Human dimensions of harmful algal blooms in coastal Peru: perceived impacts, adaptation, and governance challenges

Harmful algal blooms (HABs) can cause marine fauna mortality, human health risks, and fishery closures, thereby threatening coastal livelihoods. Despite increasing frequency and severity of HABs under climate-related and anthropogenic pressures, their social, economic, and political impacts remain understudied, especially in Latin America. To address this gap, this study explored the social-ecological dynamics of HABs in coastal Peru through 17 participatory workshops with mariculture producers, fishers, scientists, and public officials connected to the bays of Sechura and Paracas. Using fuzzy cognitive mapping, the study identified key perceived drivers, impacts, adaptation strategies, and barriers to adaptation, revealing shared understandings, but also important differences in how stakeholders interpret HABs and respond to them. We found that the most important impacts perceived were not public health effects, but losses in production, income, and employment, especially in mariculture and related coastal activities. The findings also reveal technological, information-related, and institutional disparities that make small-scale producers more vulnerable to HAB impacts compared to larger firms, potentially reinforcing existing inequalities. Simulations of proposed adaptation strategies highlighted the importance of early warning systems, emergency protocols, intersectoral coordination, and public awareness in strengthening coastal resilience in the face of HABs. Overall, the study shows that HABs in Peru are not only an ecological issue, but also a matter of unevenly distributed impacts and adaptive capacities, highlighting the need for more inclusive and equitable HAB governance.