Harmful algal blooms (HABs) are major threats to coastal ecosystems, affecting biodiversity, public health, and economic sectors such as fisheries and tourism. Using Guanabara Bay (Rio de Janeiro, Brazil)—a system heavily impacted by pollution and eutrophication—as a model, the project targets potentially toxic dinoflagellates responsible for recurrent HAB events. These organisms, often mixotrophic and capable of producing potent toxins, exhibit functional traits—cell size, surface-to-volume ratio, motility, and tolerance to physicochemical variability—that directly influence their occurrence and intensity.

DINOHAB investigates how these traits interact with environmental conditions and nutrient availability to shape HAB dynamics in Guanabara Bay. We integrate molecular ecology (DNA metabarcoding) and environmental analyses within an interdisciplinary framework to predict and mitigate harmful bloom impacts.

Objectives

• Identify and quantify dinoflagellates via microscopy and DNA metabarcoding.

• Characterize functional traits related to environmental tolerance, potential toxicity, and trophic strategies.

• Correlate functional traits with environmental variables (nutrients, temperature, salinity, pH, etc.).

• Develop predictive models for HAB occurrence and intensity.

• Propose monitoring and mitigation guidelines.

Partnerships and funding

Coordinated by ECHO – Ecotoxicology and Chemical Oceanography Research Group (CCMAR, University of Algarve), with support from the Federal University of Rio de Janeiro (UFRJ) and national/international collaborators. Funded by Instituto Serrapilheira, involving experts from Brazil, Portugal, and France.

Coordinator

Dr. Caio Cesar Ribeiro is an oceanographer and lead investigator of the Ecotoxicology and Chemical Oceanography Research Group (CCMAR – UAlg), working in the fields of chemical oceanography, marine biology, ecotoxicology, and marine pollution. He holds a PhD in Oceanography (UERJ, Brazil) and completed postdoctoral research at CESAM/University of Aveiro (Portugal). He has served as a professor at UNESP and collaborates with multiple research institutions. He participated in international expeditions, including an oceanographic mission with the Korea Institute of Ocean Science and Technology exploring hydrothermal vents in the Indian Ocean. His research spans biogeochemistry, biomarkers, microplastics, plankton ecology, and environmental impacts on marine ecosystems.

Students and activities in the project

•    Pedro Paixão – Scientific Initiation (UNESP): laboratory tests and ecotoxicological experiments with dinoflagellates and other organisms, evaluating biological and physiological responses under different environmental conditions.
•    Beatriz Maysha – Scientific Initiation (UNESP): support for molecular and microbiological analyses, including cultivation and maintenance of strains and sample preparation.
• Douglas Gonçalves – Master's Degree (Genetics/UFRJ): integration of DNA metabarcoding and trait ecology to relate morphophysiological characteristics of dinoflagellates to environmental variables and the occurrence of HABs in Guanabara Bay.
•    Isabela Guerra – Doctorate (Genetics/UFRJ): analysis of gene expression in HAB-forming dinoflagellates, focusing on toxin biosynthesis genes and their modulation by environmental conditions.

Expected publications

• Articles in high-impact journals (marine ecology, molecular biology, environmental management).

• Technical guidelines for HAB monitoring and management in Guanabara Bay.

• Technical reports for environmental agencies and decision-makers.

   

Expected impact

The project will provide essential knowledge on mechanisms regulating HABs, supporting evidence-based public policy and mitigation strategies. By integrating molecular biology, functional ecology, and environmental monitoring, DINOHAB will help preserve marine biodiversity, protect public health, and support the coastal economy.

FITOMAR partnership (UFRJ – Brazil)

DINOHAB works closely with the Marine Phytoplankton Laboratory (FITOMAR/IB-UFRJ), a national reference in molecular biology and taxonomic identification of microalgae. A core component of this collaboration is the continuous monitoring of strategic coastal ecosystems, such as the Abrolhos region. The lab is led by Prof. Paulo Sérgio Salomon (PhD in Ecology/UFRJ), whose group has a strong record of impactful publications.