How the 'evil twin' of the climate crisis is
threatening our oceans
================================================

On a clear day at Plymouth marina you can see
across the harbour out past Drake's Island -
named after the city's most famous son, Francis
Drake - to the Channel. It's quite often
possible to see an abundance of marine vessels,
from navy ships and passenger ferries to small
fishing boats and yachts. What you might not
spot from this distance is a large yellow buoy
bobbing up and down in the water about six miles
off the coast.

This data buoy - L4 - is one of a number
belonging to Plymouth Marine Laboratory (PML), a
research centre in Devon dedicated to marine
science. On a pleasantly calm May morning, Prof
James Fishwick, PML's head of marine technology
and autonomy, is on top of the buoy checking it
for weather and other damage. "This particular
buoy is one of the most sophisticated in the
world," he says as he climbs the ladder to the
top. "It's decked out with instruments and
sensors able to measure everything from
temperature, to salinity, dissolved oxygen,
light and acidity levels."

It's the hourly recordings of this last
measurement, the pH of the water, that are
adding to a picture locally and globally that is
increasingly concerning scientists.

The results show that ocean acidification is
rising - and it is doing so at an alarming rate.
Ocean acidification, often called the "evil
twin" of the climate crisis, is caused when
carbon dioxide is rapidly absorbed into the
ocean, where it then reacts with water molecules
leading to a fall in the pH of the seawater.

A paper out on Monday from scientists at PML,
the US-based National Oceanic and Atmospheric
Administration (Noaa) and Cimers (Oregon State
University), shows ocean acidification is
happening more rapidly than previously thought.

Part of the problem for scientists in bringing
it to the world's attention is that you can't
see the pH levels in the sea at the beach near
you, so how do you know it is happening?

"It's tough because there is no real smoking
gun," says Prof Steve Widdicombe, director of
science at PML and a leading global voice on
ocean acidification. "It's difficult to see the
biological effects because they're going to take
a long time to happen and differentiating the
impacts of ocean acidification from things like
temperature, fishing pressures and pollution
makes it really hard to generate impetus and
momentum in decision-makers and policymakers to
really tackle it hard."

For anyone who wants an immediate idea of its
impact, there is a very effective video from the
Noaa that shows a pteropod swimming in water
with a normal pH level, alongside one where the
pteropod has been subject to elevated CO2 levels
for two weeks. In the first video the marine
creature has a clear shell and is actively
swimming, in the second it shows a partially
dissolved and fissured shell and the pterapod
having difficulty moving in the water. Images
such as this help scientists raise awareness of
the issue, but on their own they will never be
enough.

This lack of visibility and understanding of the
impacts of acidification has led scientists to
focus on building a body of work that clearly
shows the statistical correlations between
increasing levels of acidity in the oceans and
the changes in biological processes to flora and
fauna in the sea in different areas around the
world.

A good example can be seen in the north-west of
the US. In about 2010, the oyster farming
industry there - worth millions of dollars -
nearly collapsed after oyster production seemed
to drop off a cliff.

Prof Helen Findlay from PML explains the science
of what was going on: "On the west coast you get
an upwelling of deep waters, and that deep water
has naturally got more CO2 in it. But on top of
that, you have the acidification effect from the
atmosphere, and that amplified the upwelling
effect. It turned out, after some investigation,
that the intake pipes connected to the
hatcheries were bringing in this acidified
water, which had been amplified over the years."

The level of acidity in the water had reached a
point that meant the oysters were trapped in
their larval state and unable to grow the shells
they needed to develop. The hatcheries then
installed sensors to measure the pH of the water
and added chemicals to hatchery tanks to
neutralise the water when necessary.

Scientists hope that education about initiatives
such as in the oyster hatcheries of the north-
west US, combined with government funding, will
help encourage other countries to take action
suited to their particular acidification
problem. But large parts of the world do not
have access to the information they need to
begin planning what to do.

There are obligations for countries to tackle
ocean acidification enshrined in international
agreements including, most recently, the Global
Biodiversity Framework, that aims to halt and
reverse biodiversity loss. However, while
decision-makers either lack the resources to
tackle the issue, or simply twiddle their thumbs
over implementing a plan, commercial operators
are stepping in to offer alternative solutions.

Geoengineering the ocean is becoming big
business. Companies are focusing on different
human-made ways to remove carbon from the seas,
with perhaps the most developed of these being
ocean alkalinity enhancement. This is where an
alkaline solution is added to seawater to raise
the pH level. Done at a controlled, very local
level, such as in the tanks in the oyster
hatcheries, this can be effective. But many
scientists are concerned that the ocean
geoengineering industry is growing far too
rapidly.

"We shouldn't proceed further along this road
without the evidence," says Widdicombe. "Can you
imagine going to your doctor and they say 'I've
got a drug here that will fix you.' If the
doctor then says we haven't really tested it and
we're not sure about the side effects, would you
still be happy to take it?"

Jessie Turner, executive director of the Ocean
Acidification Alliance, worries that
geoengineering may also cause people to lose
sight of the obvious. "While exploring a
research agenda around geoengineering
interventions is important, the number one
manmade solution to ocean acidification is
reducing our CO2 emissions," she says. "I hope
that we're not losing the urgency for that.
Without governments paying more attention to
ocean acidification, there is this opportunity
for the private sector to steer the course."

Aside from the primary objective of reducing
CO2, there are other things that can be done to
tackle ocean acidification, including limiting
organic pollution in the water, often relatively
easy to do at a local level, and creating more
resilient marine habitats around our shores.

It is clear, however, that scientists working in
this field are getting increasingly frustrated
with the lack of urgency around it. Many are
hoping that this week's UN ocean conference in
France will provide a vital opportunity to
discuss the problem with heads of state and get
it more firmly on government agendas.

"At the end of the day, we know CO2 is going up,
pH is going down, and that's an urgent issue
that people are not talking about," says Turner.
"It's an overlooked consequence of carbon in our
ocean that governments can no longer afford to
overlook in mainstream policy agendas, and the
time to address it is running out."



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