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We hear a lot about overfishing the ocean
but occasionally fishing is the solution to the problems facing the seas.
This is Academy scientist Luiz Rocha
catching lionfish in the Caribbean.
Lionfish are invasive in the region and are munching up the local fishes,
endangering several species.
Invasive species is a term
that scientists use to describe species
that are not where they are supposed to be.
They were transported from one place to another, by humans,
and introduced in a habitat where they didn't belong.
Lionfish are a predator and they're not native to the Caribbean
so species in the Caribbean don't recognize them as a predator
so a lot of species in the Caribbean are suffering
and many of the species that the lionfish are eating
they do have critical roles in the ecosystem.
What we can do, is control them. We can keep their numbers down
and give the native fish of the Caribbean a chance to survive.
The Caribbean fish, they will adapt to them
they will learn that they are a predator. In a lot of places they are catching them
just to try to keep their numbers down for awhile
and this is having an impact because people are going out more and more
trying to spear them and selling them to places
where they get distributed to the whole country
and sold in big numbers.
I'll take an order of lionfish sushi, please.
Pass the lionfish tacos, please.
Lionfish aren't the only invasive species causing trouble in the ocean.
Some species of fish, mollusks, plants and more
wreak havoc throughout the world's marine ecosystems.
Most of these organisms get to new locations by ship.
Not in a comfy cabin, but in the ballast water ships
carry in their hulls to keep the boats stable.
Vessels take on this water bringing life forms onboard
and discharge it in different ports with the liquid.
In fact, many governmental organizations
now have strict regulations about ballast water exchange.
Some requirements mean that ships have to their exchange water
in the middle of the ocean,
where life would have a harder time taking hold.
Some are working to treat ballast water
to make sure invasives can't hitch a ride.
Other regions are monitoring their waterways
so that if non-native species do arrive
they can't successfully take over an ecosystem.
Here's another solution to invasive species
and other threats facing the oceans: Marine Protected Areas.
Marine Protected Areas or MPAs, as they're called
can protect portions of the ocean for fish, birds, other animals
and even humans.
Some are established and run by countries.
Others, by states.
And some are even protected by local communities.
Like this MPA in the Philippines,
where local people are protecting their coastline
from overfishing, including dynamite-fishing.
Can I go to an MPA and swim? Or is it just for the fish?
It differs by the location.
In some places, you can't swim or fish at all.
Others are more open to fishing, and even ecotourism.
Marine Protected Areas are very diverse around the world.
They can be a no-take area, or they can be an area
that is a managed Marine Protected Area in which you can still fish
but it's managed, so that
there's as much sustainability incorporated as possible.
So it can remain a healthy, functioning ecosystem.
In the United States, 41% of US waters
are under some type of protection.
The one problem with Marine Protected Areas
is that there's simply just not enough.
They only protect around 4 percent of the world's oceans.
And scientists estimate that to protect marine life
we're going to need a lot more.
Look at me! I'm saving the ocean right now.
Well, you're certainly making your neighbors happy
by picking that up (laughs)
but I'm not really sure you're helping save the ocean.
Actually, she's right.
One of the biggest threats to ocean health is nutrient pollution
caused by fertilizers, sewage treatment, and even pet waste.
But nutrients sound like a good thing.
They are up to a certain point.
But too much runoff of nitrogen and phosphorous into the ocean
can cause areas known as dead zones.
When water carries these nutrients from farmlands or urban settings
into waterways that run into the ocean
the nitrogen and phosphorous may cause algae to bloom.
Many small ocean animals eat this algae
but when there's just too much of it, the animals can't keep up.
As the algae die and sink to the seafloor, they decompose
which uses up most or all of the oxygen in the water
causing dead zones.
At 7,000 square miles in area—about the size of New Jersey—
one of the largest dead zones is
where the Mississippi River feeds into the Gulf of Mexico.
Overuse of fertilizers from farmlands all along the Mississippi River
contribute to this dead zone.
If farmers use fertilizers more efficiently
it would go a long way to help solve this issue.
I can't believe using something here affects the ocean over there.
That's why, no matter where we live,
we should make sure these things don't end up in the ocean.
We can all do our part. Local actions have global impacts.