As I looked around this tropical paradise, I found myself reflecting on my own childhood in Southeast London. Downderry Primary School, where I spent my early years. The playground was concrete, and the wildest thing around was a hopscotch grid and the occasional pigeon. But, I had Mr. Smith, a teacher obsessed with the natural world. He brought in tarantulas, stick insects, and giant African land snails. That early fascination with nature stuck with me ever since. I told the rangers about this, and about my first memory of a trip to the beach in Margate. Overcast skies, chilly rockpools, and a crab I tried to keep alive in a bucket of tap water. Spoiler: it didn’t make it. But the experience stuck - the smell of the salt air, the water, the excitement.

And somehow, thirty years later, I’m still crawling around in mud, catching crabs. But this time, I was with scientists, rangers, and young leaders. Crabs are the unsung heroes of the mangroves. They stir the mud, farm food on sacrificial leaves, and move carbon through the forest floor. With CRAB-EI (Crab Remote Activity Behaviour-Ecology Index, a new monitoring method using time-lapse cameras and traps), we’re now starting to understand just how vital their role is.

The cassowary and the crab. One bold and towering in the forest, the other quiet, buried and beautiful in the intertidal zone. But both, in their own way, shape the ecosystems around them. Both are custodians of Country, and both are connected.

Cassowaries disperse rainforest seeds, connecting and regenerating entire landscapes. One of these is the seed of the cassowary plum, a fruit toxic to most animals, yet perfectly adapted to the cassowary’s gut, transforming toxicity into dispersal. By spreading these and other Lucía and Magnus setting crab traps seeds across the forest, cassowaries regenerate the rainforest, helping to hold freshwater in the landscape and slow erosion, sustaining the flow to everything downstream. Crabs, meanwhile, are ecosystem engineers. Their burrowing reshapes the mud, stirs up nutrients, and helps cycle carbon through the forest floor. They even drag mangrove leaves underground, where fungi and microbes grow across the litter. In a way, they’re farmers, cultivating their own food below the surface. Quiet, muddy work that supports life from the roots up. Their abandoned burrows even add to habitat complexity, creating tiny shelters that support a wide range of invertebrates, boosting biodiversity. These systems aren’t separate. They’re threads in the same songline. A living, breathing Country where one depends on the other to thrive. Two wildly different creatures, yet both vital, connected, and reflected in the people I met, and the Country I walked.

Just as the cassowary and the crab are connected in the roles they play across land and sea, the ecosystems they inhabit are deeply interwoven too. Rainforest, mangrove, seagrass, and reef. Each speaks in its own way. Each is connected. Mangroves trap sediment and filter nutrients carried from the forest and land. In turn, healthy mangroves, seagrass beds, and coral reefs buffer wave energy, reduce erosion, and help protect the very rainforests that feed them. Mangroves serve as nurseries for juvenile fish, crabs, and sharks, and offer shelter for estuarine crocodiles along winding tidal creeks. Seagrass stabilises the seabed and supports turtles, dugongs, and young fish. Coral reefs absorb the brunt of ocean swells and storm surges, shielding the coast and everything behind it. Each habitat supports the next, a living chain of protection, nourishment, and resilience. Connected.

In the classroom, Norm and Jock led us through the magic of mangrove science. How forest productivity is measured through litter fall, how blue carbon is captured and stored, and how these ecosystems buffer our coasts and climate. They talked us through mangrove morphology, leaves, bark, stipules, and fruits, honing our species ID. We even learned how to dry and weigh mangrove litter, turning mud-covered fieldwork into data that tells a story and has real-world impact.

“Mangroves aren’t just climate buffers. They’re cultural and economic backbones”, said Jock.

Norm added, “What is a mangrove? A salt-tolerant plant, sure, but not a single kind. Mangroves aren’t a taxonomic group, but a diverse collection of plant species from different families, all adapted to life in the intertidal zone.”

He explained how, unlike most plant categories, mangroves are defined by function, not family, shaped by convergent evolution to survive salt, tides, and sediment. That week, I learned more about coastal wetlands than I ever thought possible.

For Earthwatch and the Goondoi Rangers, this work isn’t just about data. It’s about connection.