When you picture New York City, there are
so many iconic things that come to mind. But, before the yellow cabs
and hot dog stands, New York was known
for something else: Oysters. From the 1600s through the 1800s,
New York was booming with them. And it was oysters, not hotdogs,
sold streetside by the millions. Oyster reefs covered over 220,000
acres along the coastline. The reefs were so large that ships
needed to navigate around them. But, of course,
this isn’t the case today. Oysters were overharvested
nearly out of existence, and not just in New York. Experts estimate we’ve lost 85% of the
world’s oyster reefs in the last 200 years. Today, we’re trying
to put them back. Because this animal that you
often find on a dinner plate might actually be an effective
defense against the rising ocean. We’re losing our coasts
to climate change. As oceans levels rise,
the water erodes the shoreline. This pushes the
entire coast back, encroaching on homes
and destabilizing land. So, enter the oyster. This uncharismatic
rock of an animal. STEPHANIE WESTBY: Oh come on!
You don't think they're charismatic? KIM: I feel like… It’s not
something I would call “cute.” WESTBY: No, I can't
argue with you there. I've tried, but yeah,
no, they're not. Stephanie Westby has been
helping to restore oyster reefs in the US’s Chesapeake
Bay for over 10 years. WESTBY: Their charisma really lies in
their functionality, rather than their form. Oysters obviously
don't move around. And that’s exactly
part of the appeal. Oysters stick together.
Literally. Baby oysters called “spat” attach
to older and even dead oysters in order to grow. WESTBY: And over generations,
all of these oysters reproducing, it builds up the oyster reef. In some places, that sturdy reef
can help defend the coast by dampening
the force of incoming waves. WESTBY: If you have an
oyster reef that's "intertidal" -- that sticks up at low tide -- then it can perform some of that
wave energy protection function. Oyster reefs can break up waves
by catching the brunt of the force. Part of the wave is
deflected back to the ocean, and the rest can more
gently reach the shoreline, which slows long-term erosion. On its own, an oyster reef won’t
*stop* a hurricane-level storm surge, but it could definitely
limit the damage. And the larger they grow, the
more protection they can offer: As time goes on,
sea levels will rise. Unlike man-made breakwaters,
that will need to be rebuilt over time, oyster reefs just keep
growing upward. Various organizations around the world
are working to restore oyster reefs. But reef restoration isn’t as simple
as just dumping oysters into a bay. They need something to
stick to in order to grow. In New York, one organization
puts recycled shells in cages for oyster spat to grow on, and groups in Bangladesh,
and around the US, have placed large concrete barriers
offshore for oyster spat to grow on. Now, on their own, concrete structures
like this are actually effective breakwaters. So... why add oysters? To understand, it helps to look
at a more familiar type of reef: SEAN CORSON: Oyster reefs provide
much the same function as coral reefs. They provide the same kind of habitat. They are the underpinning of the
ecological systems where they exist, just like coral reefs. Oysters are filtration systems. They eat by pulling in
large quantities of water. Algae, nitrogen, and other
contaminants are eaten, or harmlessly dumped to the bottom
of the bay, and clean water is expelled. A single oyster can filter up to
50 gallons of water every day. As the water clarity improves, sea
grasses start to grow, fish return, and other sea creatures make the
crevices in the reef their home. CORSON: They are this aggregating,
reef-building, hard structure. And so, if you look at
the way we try to deal with reducing erosion
right now, as a society, for the most part, we put rocks,
big pieces of concrete, we set up, more or less, walls,
to try to slow the rate of waves, reduce the wind-driven
erosion, that type of thing. Oysters can serve in that capacity in
many ways, but bring added advantages. Places like New York City
or even the Chesapeake Bay are way too industrialized to
bring back the reefs of the 1600s. But that’s not really the point. CORSON: I don't think we can
put it back just the way it was. I don't think that's
necessarily a realistic goal. But I think we've got a great opportunity
when we start thinking about multiple benefits, and the
different kinds of needs of society, whether it's to reduce wave impacts,
or offset nutrient inputs, or generally increasing the
health and resilience of the bay. Resiliency against the
rising oceans isn't as simple as undoing the mistakes
we made in the past. We don’t live the way we did 200 years ago,
and the world looks very different. But what we can learn from oysters, is
that restoring one species from the past can create a chain reaction
to a more sustainable future. CORSON: It feels hopeful. And it feels like something
that we can achieve.
