The ocean is at breaking-point
Radical steps are needed to preserve the precious ecosystems of the sea
But can part of this battle be fought on land?
Mangroves are evolutionary marvels
They’re a critical part of most tropical, oceanic ecosystems
But they’re rapidly disappearing
One coastal community in southern Kenya…
…has found a pioneering way to protect their mangroves…
…turning the tide on its dwindling forest…
…by harnessing one of the mangrove’s most impressive superpowers…
…kept hidden deep underground
It’s early morning and some of the residents of Gazi Bay…
…are making their way deep into the heart of a mangrove forest
They’re here to conduct a health check on this dense ecosystem
Let’s go there
That is still rocky
Let’s look for a spot here
Lilian is a lead scientist who works with the local community
The forest cover, what do you think guys?
I think 80-100%
Mangroves grow along tropical coastlines…
…and they’re the only type of tree to thrive in salt water
Where we are can be a bit deceiving
You might assume we are in a normal terrestrial forest…
…but the tides influence this place
The team has until noon to carry out its checks…
…before the forest floor floods with water
The mangroves of Gazi Bay stretch out over 615 hectares…
…but today the team is only concentrating on one small patch
They’re setting out a ten-by-ten plot
They’re checking the biomass of the trees and for signs of new growth
That’s about seven, eight, about nine metres
Mangroves are important for the health of the ocean
The nutrient-rich…
…sheltered water provides nursery habitats for numerous marine species
Another very important aspect to look at is the biodiversity
So, when we come to the forest we want to see how many crabs do we have?
Are they within the acceptable range?
What kind of species do we have?
Mangroves also help to keep the ocean clean
Their tangled root system filters dirty water as it flows into the sea
We are looking at 1.3 metres from the ground
So, about here
There’s no prop roots above this point…
…so we are going to take our diameter here
But forests like these have another superpower…
…that can help tackle one of the ocean’s…
…and the planet’s, greatest threats…
…climate change
One of the key functions of mangroves is to act as natural carbon stores…
…and they are globally significant in that function
Mark Huxham is based in Edinburgh…
…but he’s spent much of his career knee-deep in mangrove forests…
…around the world, including in Gazi Bay
Typically mangroves bury and store far more carbon than terrestrial forests
For example, at our site in Kenya there is somewhere between…
…six and eight times more carbon buried in the sediment…
…you’d expect in the soils of a tropical forest
All trees need carbon dioxide to grow
As they absorb it from the atmosphere…
…carbon becomes locked within the tree’s leaves, branches and roots
Parts of the tree eventually fall off into the soil where they decompose…
…releasing some of their CO2 back into the atmosphere
But mangroves are different
Their tangled network of roots traps this carbon-rich plant material…
…in their waterlogged soil, sealing it off from the atmosphere
This vault of carbon can remain secure for millennia…
…as long as the mangrove forests remain intact
But here’s where the problem lies
Barely half the world’s original mangroves remain
Mangroves are being lost around the world because of human impact
In the past, most of that was shrimp farming…
…removal of trees and now for palm-oil plantation
Also for coastal developments like hotels and roads
And in Africa in particular, extraction for fuelwood and for timber
So, taking a simple projection of rates of loss…
…all mangroves would disappear within the next 100 years
In Gazi Bay…
…the community has been harvesting mangrove wood for centuries
On the whole, local people who depend on their mangrove ecosystems…
…are very well aware of how important they are
However, the challenge is to find means of conserving…
…particularly to find income that will fund conservation
Many people in the area where we work are extremely poor…
…and that means relatively small amounts of money…
…can make a major difference to their lives
Mark and a group of scientists decided to join forces…
…with the local communities of Gazi Bay…
…to create a pioneering approach to protect the mangrove forest
Mikoko Pamoja, which means “mangroves together” in Swahili…
…is the world’s first community-based, mangrove-conservation project…
…that’s funded by the sale of carbon credits
Wonderful!
When we analyse for the organic matter…
…and in turn the organic carbon in this soil…
…it’s a good indicator of how much we continue to capture…
…and store by protecting this forest
They’ve found a way of making more money…
…out of the forest by keeping it alive…
…than by cutting it down
This is the major part of the carbon in a mangrove forest…
…because you can see the high content, the roots in it…
…and a lot of organic matter
So the mangroves do a lot of this in…
…capturing and storing organic matter within their soils
We convert the biomass to carbon…
…and we’re able to tell you how much carbon we have
This forest stores around 1,500 tonnes of carbon per hectare
This, again, is further converted to the carbon-dioxide equivalents…
…which are traded in the markets
They’re selling this mangrove forest’s ability to sequester carbon…
…on what is known as the voluntary carbon-credit market
Individuals and industries all create carbon emissions…
…especially in rich countries
To try to counter the damaging effect…
…people can calculate how many tonnes of carbon they emit…
…and offset this by paying carbon-capture initiatives, like planting trees…
…that can remove carbon from the atmosphere
It sounds simple…
…but it’s far from perfect
Critics of carbon accounting say it’s hard to accurately calculate…
…how much carbon any one project is sequestering…
…because there are so many varying factors to take into account
And there are other concerns, too
Carbon offsetting is controversial because some people may be…
…tempted to use it as an excuse for inaction on the climate emergency…
…and we’re very clear that offsetting is one small part…
…of our response to what we’re facing in terms of climate breakdown
But it’s got to be part of a broader…
…and coherent policy to get to a zero-carbon world
And if done correctly…
…these carbon credits provide a financial incentive for communities…
…to stop harvesting mangroves, and start protecting them
The Mikoko Pamoja project is verified…
…to sell over 2,000 carbon credits each year
This corresponds to the extra carbon storage and sequestration…
…their conservation ensures
Over the past five years this has earned…
…the surrounding villages more than $60,000…
…which the community has spent on clean water sources…
…and supplies for the local clinic and schools
As well as forest rangers who guard this precious resource
And the initiative is reaping benefits for some of those…
…who work on the ocean, too
I have been a fisherman for many years…
…ever since I was old enough to go out on the ocean
I am happy with the planting and conservation efforts
We need to plant more trees
They benefit us in many ways…
…and we have been experiencing the benefits
Sometimes when we fish around the mangroves…
…we get a bigger catch
So I can say that the mangroves have played a positive role
And if we give the mangroves time to grow…
…let’s say many more years ahead…
…the fish will indeed find a place to lay their eggs and breed more
Climate change is the overwhelming challenge of our times…
…and small projects like this…
…they are only a drop in the ocean
However, if none of us attempt these projects then nothing will happen
But Mikoko Pamoja is a pioneering model
Nearby villages are keen to replicate its success…
…and in Madagascar a similar project is already under way
We can’t hope to have the kind of world that I expected…
…when I first started studying ecology…
…as a 12-year-old birdwatcher
But that doesn’t mean that…
…we can’t have a world full of beauty and wildness…
…but we have to fight hard for it
Scientists are only now starting to understand the importance…
…of these majestic forests for the health of the ocean and the planet
Pioneers like Lilian and Mark are changing the relationship…
…between local communities and these ancient mangroves
It’s a model that could help protect ecosystems way beyond these shores