Who lives inside the Mud? A Safari to the Ria de Aveiro saltmarsh

Centre for Environmental and Marine Studies (CESAM), 22.08.2022

This summer, 65 school kids aged 3 to 10 from the Centro Escolar de Vale de Ílhavo (Portugal) visited the mudflats in the Aveiro region. The activity draws awareness for the natural treasures hidden in this unique ecosystem, and to implant an interest in STEM in the next generation, who will lead us in the future. The activity, guided by a scientific team from the Centre for Environmental and Marine Studies (CESAM), is an endorsed Ocean Decade activity.

The mudflats are unique ecosystems harbouring a diversity of organisms. Among those are barely visible and widely unknown microscopic algae named the diatoms. They use sunlight and carbon dioxide from the atmosphere to produce biomass and oxygen. “Diatoms produce tiny glass shells that can interact with sunlight”, explain Vera Cardoso and Alexandra Bastos, both part of the scientific team and Master students working in the laboratory. “We harvest these shells and study them with optical microscopes”. The laboratory investigates the optical and photonic properties of diatoms, and how diatoms interact with their environment and how they cope with changing factors.

Diatoms algae are responsible for a vast amount of the oxygen we breath.

In the early morning, the 65 school kids and their teachers were transported with a bus to the Aveiro saltmarsh, where four scientists guided the kids into the mudflat. Equipped with rubber boots, shovels and buckets, the kids enjoyed a sunny day and collected samples from the muddy and smelly sediment. So, did they find some exciting treasures? Back in the school the mud was analysed with an optical microscope, revealing the shiny and motile inhabitants – the tiny diatoms. Inspired by this experience, the kids then formed their own diatoms with playdough – which they proudly demonstrated to their parents.

The organizers Johannes W. Goessling and Silja Frankenbach were impressed by their curiosity and creativity. “We hope they will remember our Safari to the saltmarsh for a while. This is their home, their ecosystem. Once they grow up, it will be their task to take care of all this.” The activity draws attention for the urgent need to mitigate global climate change. Earth is changing at a breath-taking pace, and it will be the younger generations who must cope with it.