The man behind the mangroves
Dr Tom Worthington is an expert on coastal ecosystems. His data underlies billion-pound initiatives to save our natural world.
You’re in a dense, murky forest. A sound rises in the distance: almost like wind rushing through leaves, but not quite. It only makes sense when water laps at your feet. The tide is coming in, bringing with it small fish that dart between the tree roots. Your eyes pick out a striped trunk that appears to be moving. With a sharp breath, you recognise the flank of a Bengal Tiger.
Mangroves are the mysterious broker between land and ocean. They survive in soil flooded with saltwater and withstand the battering of waves. Their roots knit together the sediment beneath, softening the effects of erosion. They support over 700 billion juvenile fish and invertebrates as well as tigers in the Sundarbans, a mangrove forest crossing India and Bangladesh.
Coastal ecosystems like these sustain fisheries, protect the shore against storm surges, and reduce flooding on our frontlines. What’s more, they store a surprisingly huge amount of carbon.
Until recently, scientists worried that mangroves were declining so rapidly that they would disappear from some regions. But in a victory for conservation, the most recent data shows that worldwide mangrove decline is stabilising.
Our understanding of the value of these ecosystems is thanks to the work of people like Dr Tom Worthington, incoming Associate Professor of Ecology in the Department of Plant Sciences.
The man behind the mangroves
Worthington provides the foundational data for restoration projects on the biggest scale. As co-lead for science at the Global Mangrove Alliance, Worthington’s data was crucial in launching the Mangrove Breakthrough: a £3 billion initiative that aims to conserve 15 million hectares of mangroves by 2030.
“The science feeding into that initiative was developed here at Cambridge,” Worthington says. “We mapped areas where mangroves are restorable. We’ve also provided indications of how much carbon could be secured by restoring these areas.”
Worthington previously worked in Oklahoma, and was headed back to the US until the first Trump administration cut funding for his project. Since then, many more climate researchers’ careers have been derailed. US agencies warn the latest cuts will leave the country with unbreathable air and undrinkable water.
Oklahoma’s loss was Cambridge’s gain. Now, Worthington works with some of the UK’s finest conservation experts at the Cambridge Conservation Initiative. This wider network of collaborators is crucial, allowing Worthington to provide the world’s leading NGOs and scientific organisations with reliable, actionable data on coastal ecosystems.
Tom at work in his office.
Tom at work in his office.
“With the latest satellite sensors, we can identify deforestation much quicker. We can send alerts to teams on the ground, who can then go and investigate the cause.”
Dr Tom Worthington
The view from on high
With collaborators at Aberystwyth University, Wetlands International and The Nature Conservancy, Worthington developed the Global Mangrove Watch platform. The tool brings together massive datasets on the state of the world’s mangroves. With freely available maps, users can see changes in these ecosystems from on high, made possible by satellite imagery.
Worthington says, “The platform lets you see how mangrove areas have changed over the last few decades. It’ll tell you the carbon values of that area, as well as the restoration potential.”
By using the latest data and machine learning techniques, this research community has ushered in a new era. Environmental monitoring is now lightning fast and remedial action can be laser targeted.
“With the latest satellite sensors, we can identify deforestation much quicker,” says Worthington. “We can send alerts to teams on the ground, who can then go and investigate the cause.”
Communities can take a variety of actions to stop ecosystems declining. They can fence off areas to stop overgrazing, remove harmful dams, or find more sustainable ways to provide the same economic benefit for local populations.
Screenshot from the Global Mangrove Watch platform, showing the Sundarbans' mangrove coverage from above.
Screenshot from the Global Mangrove Watch platform, showing the Sundarbans' mangrove coverage from above.
These monitoring tools are still fresh, and their capacities are getting better all the time. Given the pressing nature of the climate crisis, we don't have the luxury of waiting to see if projects will work.
“We need to know now,” Worthington says. “If restoration projects are not on the right track, they need swift remedial action.”
“In South America, for example, you see these incredible patterns in the satellite imagery. Long mud-flats develop on one end while being eroded on the other, and so the mangroves will colonise new ground and shift along the coastline. Environments like these are cyclical and constantly changing. But if humans are damming rivers and building structures on the coastline, this changes the dynamics even further.”
While mangroves have got a lot of attention, Worthington thinks we’ve overlooked the importance of salt marshes.
That’s why his team have produced the world’s first remote-sensed map of salt marshes. In addition to this work, Cambridge’s Dr Tania Maxwell developed the first global map of soil carbon in tidal marshes.
Worthington hopes that this early work on marshes will eventually replicate the success of mangrove restoration.
His team provide a bird’s eye view of our changing planet. By making the bigger picture available to all, their tools point us in the right direction, and vastly increase our chances of success.
Published on 23 June 2025.
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