Harmful Algal Blooms and Biotoxins – a One health Approach to Early Warning Systems

Harmful algal blooms (HABs) represent a growing global challenge, threatening human, environmental, and animal health, while also causing substantial social and economic impacts. Certain algal species produce potent toxins that can accumulate in marine organisms and eventually enter the human food chain, potentially causing a variety of human illnesses. High-biomass HABs can also deplete ocean oxygen, produce hydrogen sulfide, and lead to massive fish kills, including in aquaculture sites. In addition, the impact on desalination plants, conducting to reduced or closure of activities are becoming emerging challenges globally. HABs are thus a food safety and food security threat through seafood contamination above safety levels, aquaculture site closures, ban of certain fish species trade, mass mortalities, human illnesses and drinking water limitations. These challenges are diverse in nature, and their solutions vary across different social configurations around the world  and require a multifaceted approach. 

This study explores the intersection of environmental, social, animal health, and human health disciplines, and emphasizes the perspectives of various stakeholders, including coastal communities and industries, and on scales ranging from local to global. We present insights gained from the practical experiences in two African countries to pilot test the recently published Technical Guidance for Early Warning Systems (EWS) for HABs (FAO, IOC-UNESCO, and IAEA). We highlight the necessity of an integrated, transdisciplinary, science-based approach to enhance the prediction of HAB events, improve alerts, which go beyond monitoring systems, and develop effective responses to ensure sustainable access to safe seafood and promote fare trades. An integrated One Health approach incorporates environmental monitoring, marine biotoxin detection, predictive model development, socio-economic assessments, ocean literacy, public health surveillance, all while fostering collaboration across sectors and stakeholders, involving not only marine scientists and health professionals but also local communities, policymakers, and the private sector. Although EWS solutions for HABs will always require location-specific considerations, international technology and information exchange are inherent to this approach guided by open science principles. Ultimately, this approach aims to mitigate the impacts of HABs, reduce economic losses in the seafood industry, and improve food safety and security while supporting the continual and sustainable development of seafood production and marine ecosystems.