In this episode, we meet Marcello Vichi, a biogeochemist working on understanding the ocean’s role in climate regulation. Marcello explains the science behind biogeochemical processes in the ocean and why such complex systems can be difficult to model and predict. In a world where the ocean is a crucial part of our climate system, these insights are more important than ever.
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At the heart of Marcello’s research is biogeochemistry, which investigates how chemical elements such as nutrients are cycled through the ocean’s vast ecosystem, driven by a microscopic world of organisms. While it may seem simple on the surface, the ocean’s biogeochemistry is a highly complex system with many interdependencies—processes that are often influenced by unseen factors, like the turbulence of water movement.
The difficulty in biogeochemical modelling lies in the inability to track every single microscopic interaction. Instead, scientists rely on mathematical models that approximate how these systems work on a larger scale.
Marcello works in the Southern Benguela current, a vital upwelling system that sustains one of the most productive fisheries in the world. Here, the ocean brings nutrients to the surface, feeding an ecosystem that humans rely on heavily for food and income. However, this system is complex, with unpredictable fluctuations—sometimes leading to harmful algal blooms or low-oxygen conditions that can devastate the marine food web.
With climate change and human activity intensifying the challenges to ocean systems like the Benguela, understanding these dynamics has become increasingly important. Through models and experimentation, Marcello’s team is working to better predict when these disturbances will occur and how they’ll affect the ecosystem. Their goal is to improve the ability to forecast these disruptions, allowing fisheries to adapt and minimize the impact.
Marcello also highlights how the increasing availability of satellite data has revolutionized ocean science. Satellites provide high-frequency, continuous data that help scientists monitor large-scale oceanic changes. However, satellites have limitations—particularly when it comes to observing conditions near the coastline or capturing fine-scale details. This is where biogeochemical models come in. These models bridge the gap by incorporating satellite data and other measurements to make predictions about ocean behaviour in areas that satellites can’t reach. While the models are not without uncertainty, Marcello emphasizes how they can still provide crucial information about how the ocean is absorbing and cycling carbon—a topic of critical importance in the fight against climate change.
Looking forward, Marcello is hopeful about the future of biogeochemical modelling. The ultimate goal is to improve our ability to predict how ocean systems will respond to climate change, which will help us manage the ocean more effectively.