A new IAEA coordinated research project (CRP) will investigate how eutrophication contributes to the development of Harmful Algal Blooms (HABs) and their associated toxins. The findings will contribute to reducing the impacts of HABs on seafood safety and water quality.
HABs, often characterized by the proliferation of algae, potentially producing biotoxins that adversely affect ecosystems and human health, represent a growing socio-ecological global concern. Yasmine Bottein, Professor at Université C?te d'Azur, said: “Biotoxins can accumulate in marine organisms that are consumed by humans, posing serious risks to food safety, food security and public health.”
“Toxic HABs have been linked to well-documented seafood-related syndromes, including amnesic, diarrhetic, neurotoxic and paralytic shellfish poisoning, as well as ciguatera. As aquaculture now surpasses wild fisheries in global seafood production and continues to expand, understanding these natural phenomena is more critical than ever,” Bottein noted.
Non-toxic HABs can also cause detrimental effects through the development of high biomass, which can lead to the depletion of oxygen and the destruction of marine habitats. These impacts on marine life can have negative consequences for fisheries, tourism and recreation sectors.
The frequency and severity of HABs are closely linked to eutrophication - the process where a body of water becomes overly enriched with nutrients, primarily nitrogen and phosphorus, leading to the excessive accumulation of biomass. Anthropogenic sources, including agricultural runoff, wastewater discharge, and industrial pollution, significantly contribute to nutrient loading in coastal waters, creating favorable conditions for algal proliferation. Local hydrodynamics, biotic interactions or nutrient speciation (inorganic vs organic) and ratios (N, P, Si) also control HAB dynamics.
The consequences of climate change such as marine heat waves, extreme weather events and sea level rise, as well as increased shipping activities and coastal use adds to local anthropogenic pressures, such as nutrient pollution. However, scientists still do not fully understand the frequency and amount that combined local pressures, global factors and climate change contribute to eutrophication and as well as the frequency and severity of HABs, information which is crucial to mitigate their harmful impacts. “Through this CRP, the IAEA will support the development, refinement and application of nuclear and isotopic techniques to assist member countries in assessing the link between eutrophication and HABs in their coastal areas,” said Carlos Alonso Hernandez, Research Scientist in the IAEA Radioecology Laboratory.
CRP Overall Objective:
The overall objective is to understand how nutrients flowing from land to sea in coastal eutrophication can cause formation of HABs and biotoxins in light of global and climate change and other environmental drivers. This objective contributes to the development of mitigation measures to combat the impacts of HABs on seafood safety, water quality, coastal community health and tourism. The findings of this CRP will also provide actionable knowledge to assess nutrient pollution and its sources for coastal zone management programs of member countries.
Specific Research Objectives:
- Identify and characterize key abiotic (e.g. physicochemical) and biotic (e.g. grazing, viral lysis, allelopathy) drivers of HABs through the usage of isotopic techniques.
- Improve the understanding of toxin biosynthesis, accumulation and transfer in marine ecosystems using nuclear and isotopic techniques.
- Reconstruct the relationship between eutrophication and HABs in the recent past by correlating cyst records in sediments with human-induced environmental changes.
- Prepare research findings for effective dissemination to relevant stakeholders and the broader scientific community.
How to join this CRP:
This CRP is intended to be complementary to the CRP on Submarine Groundwater Discharge, which supports research on land-to-sea nutrient fluxes and their link to eutrophication. While we appreciate applications to both CRPs by the same institution or collaborations between two institutions applying for one CRP each at the same study site, we also value individual applications to either CRP.
Research institutions interested in joining the CRP must submit their Proposal for Research Contract or Agreement via email, no later than 31 July 2025, to the IAEA’s Research Contracts Administration Section, using the appropriate template on the CRA web portal. The same template can be used for both the research contract and technical contract. The IAEA encourages institutes to involve, to the extent possible, women and young researchers in their proposals.
For further information related to this CRP, potential applicants should use the contact form on the CRP page.
