Transcriber: Anson Tang Reviewer: Ale Heredia Allegretti
There are different types of marine biologists.
You have the ones
that study dolphins,
corals and oysters and conduct their research in pristine areas of deep waters,
coral reef or mangrove shorelines. And there are different ones.
I’m one of those.
My name is Dr. Ido Sella, and I’m a marine biologist that specialize in
the biology of industrial and urban waterfronts.
I’m one of those who dive at ports and outlets of power plants and study
the biology that developed on piers, breakwaters and bridge foundations.
If you had a chance to catch a ride with Richard Branson or Jeff Bezos,
to space and you look back at Earth at night,
this is what you’ll see. 50% of world population reside along coastlines,
and the growth of this 50% is occurring faster than human population
growth in general. It turns out that most of us are beach bums.
This huge mass of people require different coastal infrastructure to
supportive needs. If it’s ports to deliver goods, breakwater to protect our cities
or bridges for transportation or many other structures that are built where
the sea meets the land. We’re putting immense pressure on our waterfronts.
Our cities and industrial area doesn't stop at the waterline.
They go deeper into the water and replace some of the richest habitats
on Earth with manmade structures such as seawalls, piers, piles and pipelines.
And this is happening in our closest waterfront,
where we live and work and commute exactly
the places where we need those prices
the ecosystem services such as CO2 sequestration, water filtration,
fish reproduction sites, biodiversity or just our near home accessible nature.
The thing is that for many years,
we consider the sea in front of our urban industrial waterfronts
as our dirty old yards. A place that nobody actually sees or visit.
Many coastal cities from Mumbai to New York don’t promote people interaction
with water due to health concerns.
For years, we mistreated our waterfronts.
The closest option to interact with nature
for more than 50% of world population,
and we lose those valuable resources in the place we need the most! As being
a part of the other type of marine biologists,
I study the difference between natural marine ecosystems and manmade ones.
Coral reef, oyster beds, seagrass or mangrove provide
a range of ecosystem services such as carbon sequestration,
water filtration, nurseries for juvenile fish, biodiversity
and other ecological factors that cannot be found in organizing
industrial waterfronts. Why is it?
Why those waterfronts are usually associated with poor water quality,
low biodiversity and the dominance of invasive species?
If we want to figure this out,
we will need to dive in and understand how those structures are designed
and what are they built from. Well, the answer is actually simple.
It’s mostly concrete. 70% of world coastal infrastructure,
are concrete based. This material, that is responsible
for 4 to 8% of world’s CO2 emissions is used for
the construction of ports,
breakwaters, outflows and many other structures along our coastline.
It is cost-effective, accessible and durable,
and it’s the natural’s choice for construction in many parts of
the world. Now, maybe a quick stop for biology one-on-one.
One of the unique differences between the life on land and the life in
the water is that on land only plants leave their own life at one point
completely stationary. And in the water, both plants and animals do that.
Coral, oysters, mussels and barnacles are swimming as little babies in
the plankton until they choose where to settle,
and then once they find the good spot, they will be there for life.
And apparently, most of those guys don't think our coastal infrastructure is
a good spot. Well. In the last two decades, my dear friend and colleague,
Dr. Shimrit Perkol-Finkel and myself studies ways to make coastal
infrastructure a good spot. And naturally, we focused on concrete.
We started with tweaking concrete in the lab
and checking how this affected its ability to support
the growth of different organisms.
And in a certain point, we found a way to make concrete support, more biology,
a way to have more species growing on the concrete.
Then we move and tested this new concrete in
the sea with different surfaces at different locations around the world.
And once we pulled those tests out,
we found that not only we can make concrete support
much more species of marine organisms,
we can also gain other advantages from this living crust.
This cover that you see on the screen is made from shells of oysters
and other marine organisms that secrete calcium carbonate in order to attach
themselves to the surface.
I'm talking about corals and oysters and barnacles and two wars that,
with time encapsulate the concrete in what we called biogenic buildup.
This buildup create the thriving habitat and attract more species to forge
and find shelter on the surface.
But it's not only that in the process in which those organisms create their shells,
carbon dioxide is absorbed and fixed.
We can now harness the waterfront to support ecology
and carbon dioxide sequestration,
1km of a modified concrete seawall can consume out of
the atmosphere, around 2 tons of CO2 each year.
This is the same amount of CO2 that is consumed by 100 adult trees at
the same time. The ability to make coastal infrastructure support healthy
biological communities means we can bring those missing ecosystem services to
urban industrial waterfronts.
We are now able to better protect our shorelines from storms
and sea level rise while supporting nature and using nature to support us.
Look at this image showing a one year old project with the standard concrete units
and the modified ones that were installed at the same day.
This biological crust is not just better for the ecology,
it's also protecting the infrastructure and encapsulate the surface and glue
the units together, making the infrastructure more resilient.
This is buyer protection in practice.
Concrete with a cover of oyster can be 10 times stronger than bare concrete.
Seawalls that are covered with barnacles and algae will develop less cracks
and thus require less maintenance and have a longer lifespan.
I guess it's true that only after you lose something,
you start to appreciate it. More and more port cities
and other coastal asset border are now looking for ways to increase biodiversity,
water quality and other ecological factors in the water
and bring back those needed ecosystem services.
Bio-enhanced waterfronts are more resilient to climate change,
has a carbon dioxide sequestration capabilities
and provide ecosystem services that are missing in orbiting industrial waterfront.
We can now reconnect to our waterfronts and construct our ports,
breakwaters and waterfronts in a more responsible way.
It’s actually a win-win solution with both for the environment and
for our infrastructure.