The UN Sustainable Development Goal 14
aims to conserve and sustainably use the oceans,
seas and marine resources for sustainable development.
So, how are we doing?
Many marine species, habitats and ecosystems
have suffered catastrophic declines
and climate change further undermines ocean productivity and biodiversity.
Did you know that a substantial fraction of the coastal ocean
suffers from pollution, putrefaction and oxygen depletion?
Our oceans are stressed by warming
and many marine species are threatened with extinction.
I’m Tracey Rogers and I’m a Professor of Ecology at UNSW
in the School of Biological, Earth and Environmental Sciences.
Let’s look at the first of the key targets
which is to reduce marine pollution.
Around 8 million metric tons of plastic enters our oceans each year.
This is equivalent to 16 shopping bags full of plastic
for every meter of coastline excluding Antarctica.
So, we’re not doing so good.
In fact, the rate at which plastic finds its way into our ocean
is increasing and by 2025 it’s predicted
that we will be putting enough plastic in the ocean
to cover 5% of the earth’s entire surface in cling wrap; that’s each year.
So, does it matter that there is so much plastic in the ocean?
Globally, about one third of all turtles
are likely to have eaten plastic in some form,
but lots of marine animals mistake plastic for food,
such as seals, fish, and whales.
At least 690 marine species
have been documented to have encountered with plastic marine debris.
Either they have eaten it or they’ve become entangled in it.
Of those species, at least 17% are vulnerable,
listed as either near threatened, endangered, or critically endangered.
Seabirds such as albatross, gannets, shearwaters,
and petrels are particularly vulnerable.
Unfortunately, many of these seabirds are already at risk.
So, where is this plastic coming from?
All over the world.
The darker the color of this figure,
the more mismanaged plastic that country has.
So, more likely their plastic will end up in the ocean.
Gold star for New Zealand, Namibia, Amman,
the Scandinavians, and the Canadians.
But it doesn’t matter who produces this marine plastic,
because once it’s in the ocean it travels in ocean gyres around the world.
Inside the gyres the water is stationary
and it’s here that plastics accumulate.
Over time, garbage patches form
and the most well known is the Great Pacific garbage patch,
but there is a garbage patch in each of our ocean basins.
What can we do about it?
How about your weekly shop?
The container your apples come in or the plastic bag that you put them in?
These are single use plastics.
So, how do I get out of the shop
without using any of these single use plastics?
First start, those plastic bags,
one trillion single use plastic bags made globally in 2019.
Replacing them with reusable bags is an easy start
and one we’re all embracing anyway.
Lots of countries have banned plastic bags already.
Rwanda did this back in 2008.
Bottled water; in Australia we use 118,000 tons
of single use water bottles every year, and that’s just Australia.
By the way, our tap water is fine,
often better tasting than the stuff you buy in a bottle,
unless you live in Adelaide,
or if you’re buying that lovely Norwegian water,
but you get my meaning.
So, replacing bottled water with your own reusable bottle,
and if councils provide water taps around town,
this easily eliminates another 200,000 tons of plastic every year.
All we need is a couple of public taps.
But managing our waste is also important.
Did you know that only about 40% of those plastic bottles are recycled?
The rest go to land fills or to our waterways.
A discarded water bottle will take at least 1000 years to biodegrade,
but that doesn’t mean it’s gone,
just that it’s broken down into thousands
and even millions of tiny pieces, into microplastics,
that can make their way into our food and water.
A second key target is to reduce ocean acidification.
So, what is ocean acidification?
As our activities have pushed more carbon dioxide into the atmosphere,
lucky for us, a great deal of this extra carbon dioxide
has dissolved into seawater.
The oceans have been like a giant sponge,
absorbing up to 30, even 40% of our extra carbon emissions.
But what happens when this extra carbon dioxide dissolves into seawater?
Well, the carbon dioxide and water molecules reconfigure
and they make carbonic acid.
But many marine creatures use calcium carbonate
to make their shells and skeletons,
and in more acidic oceans they can’t do this,
they can’t make those shells properly.
Now, from blue whales to plankton, the oceanic food web is complex.
And although plankton are tiny,
they are vital for many of the species higher up in the food chain.
If these tiny plants and animals at the base of the food chain
can’t make their shells,
this will have a flowing effect
that will change the very composition of our oceans.
Another of the key targets is to fish sustainably.
Yet, at least one third of our fish stocks are over fished
and one third to half of vulnerable marine habitats have been lost.
What can we do?
Well, buying locally caught fish rather than imported fish,
this means not only can you find out where your seafood was caught,
whether it was caught in a sustainable fashion, it will also taste better.
Where you buy tinned or imported seafood,
check the labels for how it was caught, read the label carefully.
If you’re buying tuna, see what type of tuna you’re about to buy,
as some species are endangered.
Only buy seafood with labeling that tells you what the species is,
where it was caught, and how it’s been caught,
and the way to do this more easily is to buy seafood
that has the Marine Stewardship Certification, an MSC tick.
The MSC labeling enables all products to have total traceability.
This means you can track what you buy from catch to plate
as it is packed and frozen on the boat.
This is an easy way to make sure
you’re eating seafood taken from a sustainable fishery.
Achieving Sustainable Development Goal 14 is achievable.
We can conserve and sustainably use our oceans,
seas, and marine ecosystems.
Biodiversity losses in the ocean are less pronounced than those on land
and many marine species are capable of recovery
once pressures are reduced or removed.
However, achieving this goal
will require rebuilding marine life as the life support systems,
the populations, the marine habitats and the ecosystems
that deliver many benefits society receives from our healthy oceans.