When we think about cleaning the ocean, we often imagine divers removing ghost nets or volunteers collecting plastic from the shore. But beneath the surface, nature has its own recycling systems.

In this episode of our Ocean’s Natural Cleaning Crew series, we turn to one of the most overlooked and most underestimated marine animals: the sea cucumber.

Joining us is Prof Annie Mercier, Department of Ocean Sciences, Memorial University (Canada), who has spent decades studying these remarkable creatures and co-edited the comprehensive scientific volume The World of Sea Cucumbers.

The “earthworms” of the ocean

Sea cucumbers play a vital but often overlooked role in marine ecosystems. Like earthworms on land, they process seabed sediments, recycle nutrients, and help keep ocean floors oxygenated. On coral reefs, they may even support coral health by reducing harmful bacteria.

Despite their simple appearance, sea cucumbers are incredibly diverse, ranging from tiny species to over a meter long, and living in environments from shallow reefs to deep-sea trenches. Their biology is equally remarkable — some can regenerate organs, split in two, and live for decades, making them valuable for scientific research on aging and regeneration.

However, rising global demand has led to overfishing, putting many populations at risk. Losing them doesn’t just remove a species — it disrupts essential ecological processes that keep marine ecosystems balanced.

Sea cucumbers may not be iconic ocean animals, but they are quiet engineers of resilience — and far more important than we often realize.

🎧 Listen to the full episode to discover why these humble creatures matter so much.

Further links to the topic:

• IUCN SSC Sea Cucumber specialist Group: https://iucn.org/our-union/commissions/group/iucn-ssc-sea-cucumber-specialist-group
• Prof. Annie Mercier lab's website: https://www.mercier-lab.ca/
• The open-access conservation paper: https://doi.org/10.1146/annurev-marine-032123-025441
• Book https://www.sciencedirect.com/book/edited-volume/9780323953771/the-world-of-sea-cucumbers

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Healthy Seas is a marine conservation organization whose mission is to tackle the ghost fishing phenomenon and turn this waste into an opportunity for a more circular economy. They do this through clean-ups, prevention, education, and working with partners who recycle and repurpose this material. The podcast is hosted by Crystal DiMiceli.

In this episode of our “Ocean’s Natural Cleaning Crew” series, marine scientist Erik Wurz reveals how sponges filter water, recycle nutrients, and quietly sustain marine life

Most of us think of ocean protection in terms of visible action: removing nets, collecting waste, monitoring habitats. But beneath the surface, nature has its own clean-up teams: organisms that filter water, recycle nutrients, and make marine ecosystems possible.

In this episode of our series on marine life that helps keep the ocean clean, we meet one of its most overlooked workers: the sponge.

Marine biologist Erik Wurz (University of Helsinki) takes us into a world most people never notice: animals that can look like paper sheets, chimneys, or giant vases, quietly pumping water through their bodies day and night.

A football-sized sponge, he explains, could filter up to 30,000 liters of seawater per day, removing bacteria, particles, and dissolved matter and releasing ultra-clean water back into the ocean. But their role goes far beyond filtration.

By transforming microscopic organic material into edible particles, sponges effectively kick-start marine food webs, making energy available to fish, invertebrates, and entire ecosystems. Without them, many marine habitats would struggle to sustain life. In some parts of the deep sea, they even form vast “animal forests,” structures that provide shelter, breeding grounds, and feeding platforms for countless species.

And yet, despite their importance, sponges remain largely invisible in public imagination overshadowed by more charismatic marine animals. That’s something Erik hopes to change: “I hope this podcast helps make sponges cool.”

The conversation also explores how climate change, sediment disturbance, and bottom trawling can disrupt sponge ecosystems with long-term consequences for fisheries, ocean health, and even potential biomedical discoveries hidden within sponge microbiomes.

If Healthy Seas teams remove debris in marine habitats, sponges do something incredibly remarkable too — continuously and silently — by filtering, recycling, and sustaining the ocean from within.

This episode invites us to look again at the seabed and many other places and notice the quiet workers already keeping it alive.

Healthy Seas is a marine conservation organization whose mission is to tackle the ghost fishing phenomenon and turn this waste into an opportunity for a more circular economy. They do this through clean-ups, prevention, education, and working with partners who recycle and repurpose this material. The podcast is hosted by Crystal DiMiceli.

If you enjoyed this episode, please be sure to subscribe, rate and review it! This helps to boost its visibility.

Healthy Seas is a marine conservation organization whose mission is to tackle the ghost fishing phenomenon and turn this waste into an opportunity for a more circular economy. They do this through clean-ups, prevention, education, and working with partners who recycle and repurpose this material. The podcast is hosted by Crystal DiMiceli.

When Nature Has a Number on the Balance Sheet

How the financial world is starting to recognize the value of ecosystems services

In this episode of the Healthy Seas Podcast, we sit down with Dr. Ralph Chami — financial economist, former Assistant Director at the International Monetary Fund, and Co-Founder of Blue Green Future — to explore one of the most powerful shifts underway: integrating the value of nature’s services into economic and financial systems.

From whales and seagrass to elephants and bison, Ralph’s work centers around measuring the economic contributions of living ecosystems and designing financial tools that recognize their role in climate regulation, biodiversity support, and human wellbeing. The goal? To accelerate funding for restoration and protection by making nature visible on the balance sheet.

A Whale, a Shift, a New Vision

The conversation begins with a deeply personal story: a moment in the Sea of Cortez that transformed Ralph’s life and career. From that encounter with a blue whale came a new path, one that brought together climate science, conservation, and high-level economics. Since then, Ralph has helped governments and organizations understand how to value nature’s services — not to commodify ecosystems, but to make the case for investing in their preservation and restoration.

In the episode, you’ll hear about:

• Why whales can be worth millions over their lifetime through carbon storage
• How forward contracts are being used to fund environmental restoration
• What makes a nature-based project “investable”
• Why markets are slow to respond — and what could unlock faster change
• The role of communities in managing and benefiting from ecosystem services
• The risks of leaving nature outside the financial system, and how to avoid them

When Oceans Meet Economics

For companies, investors, and governments trying to build credible climate and biodiversity strategies, this episode offers a new lens. As Ralph puts it, valuing nature’s services isn’t about replacing conservation with markets — it’s about finally recognizing the systems we depend on, and funding their protection before it’s too late.

It’s a bold reframe of where value lies, and how finance can be part of the solution.

If you enjoyed this episode, please be sure to subscribe, rate and review it! This helps to boost its visibility.

Healthy Seas is a marine conservation organization whose mission is to tackle the ghost fishing phenomenon and turn this waste into an opportunity for a more circular economy. They do this through clean-ups, prevention, education, and working with partners who recycle and repurpose this material. The podcast is hosted by Crystal DiMiceli.