In this episode of Big Ideas Only, host Mikkel Svold sits down with Kasper Elgetti Brodersen, Associate Professor at Roskilde University, to explore the science behind one of our most overlooked coastal ecosystems: seagrass meadows. What looks like an annoyance when it brushes against your legs while swimming turns out to be a biological powerhouse — nursery grounds for fish, carbon storage systems, and water quality filters all in one. Kasper explains how seagrass interacts with sediments and bacteria, why nutrient runoff from farmland is suffocating Danish fjords, and the surprising discovery that stressed seagrass can flip from climate helper to greenhouse gas emitter. The conversation covers what makes restoration so difficult, why seeds might be better than transplants, and what still needs solving before we can successfully garden the sea.
In this episode, you'll learn about:
Why seagrass provides four times the ecosystem services of coral reefs (measured in economic value)
How seagrass creates its own oxygen supply to survive in toxic, oxygen-free sediments
The mechanism that turns nutrient pollution into plant-killing hydrogen sulfide
Why stressed seagrass meadows can start producing methane and nitrous oxide instead of capturing carbon
What makes restoration in Danish fjords so challenging — and why seeds might work better than transplants
The bacterial partnerships happening underground that help seagrass access nitrogen
Episode Content 01:13 Why seagrass is a big idea 03:11 Global distribution and the 70% loss in Danish waters over the last century 05:07 The main stressor: eutrophication from agricultural nutrient runoff 07:15 How seagrass survives in anoxic sediment by pumping oxygen through internal channels 08:56 Epiphytes explained 10:17 What healthy conditions look like 15:09 The eureka moment: discovering seagrass provides more ecosystem value than coral reefs 19:26 Below-ground interactions: how oxygen release acidifies sediment and mobilizes nutrients 20:22 The greenhouse gas twist 30:32 Why restoration is still so hard 41:04 What's happening in the rhizosphere
Podden och tillhörande omslagsbild på den här sidan tillhör
Montanus. Innehållet i podden är skapat av Montanus och inte av,
eller tillsammans med, Poddtoppen.
