A healthy ocean

1.

Quotes
Even if you never have a chance to see or
touch the ocean, the ocean touches you with
every breath you take, every drop you drink,
every bite you consume. Everyone,
everywhere is inextricably connected to and
utterly dependent upon the existence of the
sea.
Our oceans are the natural treasure upon which
marine and coastal resources and industries have
been able to flourish and which today represent
more than five percent of global GDP.

2.

A healthy ocean means a healthy planet!

3.

Noise pollution 'drowns out ocean soundscape

4.

Researchers say evidence of the harm ocean noise
pollution can do has been building for decades
Noise from shipping, construction, sonar and
seismic surveys is "drowning out" the healthy
ocean soundscape, scientists say.
And an "overwhelming body of evidence" has
revealed the harm human-made noise does to
marine life.
"We've degraded habitats and depleted marine
species," said Prof Carlos Duarte, who led the study,
said.
"So we've silenced the soundtrack of the healthy
ocean and replaced it with the sound that we create."

5.

Sound is a fundamental cue
"Sound is a fundamental cue for feeding, navigation, communication and
social interaction in the ocean," he told BBC News.
A great deal of the decades of research into ocean sound has focused on
marine mammals such as humpback whales that communicate across vast
distances with complex and mysterious songs.
But Prof Duarte said there was evidence even newly hatched fish larvae
were now unable to hear "the call of home" when drifting in the vast ocean.
"We now know that [these tiny larvae] hear the call from their habitat and
follow it," he said.
"And that call is no longer being heard."
Marine scientist Dr Heather Koldewey, from the Zoological Society of
London, said that the underwater realm was a "a cacophony of sound as
animals meet, greet, breed, and use noise in a variety of ways".
"It's is an important yet overlooked aspect of what constitutes a healthy
ocean," she added.

6.

The soundscape of even the most pristine ocean
environments has been altered by human activity

7.

But the scientists pointed out that the global
lockdown revealed how quickly and easily the
problem of noise pollution could be solved.
"Last year, when 60% of all humans were in
lockdown, the level of human noise [in the ocean]
reduced by about 20%," said Prof Duarte.
"That relatively modest reduction was enough for a
wave of observations.
"Large marine mammals - the easiest to observe were seen near coastlines and in waterways that
they'd not been seen in for generations."

8.

And this showed tackling this marine "anthrophony"
was the "low-hanging fruit" of ocean health.
"If we look at climate change and plastic pollution,
it's a long and painful path to recovery," Prof Duarte
said.
"But the moment we turn the volume down, the
response of marine life is instantaneous and
amazing."

9.

An anthropogenic cacophony
Sound travels faster and farther in water than in air.
Over evolutionary time, many marine organisms
have come to rely on sound production,
transmission, and reception for key aspects of their
lives. These important behaviors are threatened by
an increasing cacophony in the marine environment
as human-produced sounds have become louder and
more prevalent. Duarte et al. review the importance
of biologically produced sounds and the ways in
which anthropogenically produced sounds are
affecting the marine soundscape.

10.

BACKGROUND
Sound is the sensory cue that travels farthest through the
ocean and is used by marine animals, ranging from
invertebrates to great whales, to interpret and explore
the marine environment and to interact within and
among species. Ocean soundscapes are rapidly changing
because of massive declines in the abundance of soundproducing animals, increases in anthropogenic noise,
and altered contributions of geophysical sources, such as
sea ice and storms, owing to climate change. As a result,
the soundscape of the Anthropocene ocean is
fundamentally different from that of preindustrial times,
with anthropogenic noise negatively impacting marine
life.

11.

ADVANCES
We find evidence that anthropogenic noise negatively
affects marine animals. Strong evidence for such impacts
is available for marine mammals, and some studies also
find impacts for fishes and invertebrates, marine birds,
and reptiles. Noise from vessels, active sonar, synthetic
sounds (artificial tones and white noise), and acoustic
deterrent devices are all found to affect marine animals,
as are noise from energy and construction infrastructure
and seismic surveys. Although there is clear evidence that
noise compromises hearing ability and induces
physiological and behavioral changes in marine animals,
there is lower confidence that anthropogenic noise
increases the mortality of marine animals and the
settlement of their larvae.

12.

OUTLOOK
Anthropogenic noise is a stressor for marine animals. Thus, we call
for it to be included in assessments of cumulative pressures on
marine ecosystems. Compared with other stressors that are
persistent in the environment, such as carbon dioxide emitted to the
atmosphere or persistent organic pollutants delivered to marine
ecosystems, anthropogenic noise is typically a point-source
pollutant, the effects of which decline swiftly once sources are
removed. The evidence summarized here encourages national and
international policies to become more ambitious in regulating and
deploying existing technological solutions to mitigate marine noise
and improve the human stewardship of ocean soundscapes to
maintain a healthy ocean. We provide a range of solutions that may
help, supported by appropriate managerial and policy frameworks
that may help to mitigate impacts on marine animals derived from
anthropogenic noise and perturbations of soundscapes.

13.

Changing ocean soundscapes
The illustrations from top to bottom show ocean soundscapes
from before the industrial revolution that were largely
composed of sounds from geological (geophony) and
biological sources (biophony), with minor contributions from
human sources (anthrophony), to the present Anthropocene
oceans, where anthropogenic noise and reduced biophony
owing to the depleted abundance of marine animals and
healthy habitats have led to impacts on marine animals. These
impacts range from behavioral and physiological to, in
extreme cases, death. As human activities in the ocean
continue to increase, management options need be deployed
to prevent these impacts from growing under a “business-asusual” scenario and instead lead to well-managed
soundscapes in a future, healthy ocean. AUV, autonomous
underwater vehicle.

14.

A healthy ocean
Oceans have become substantially noisier since the Industrial
Revolution. Shipping, resource exploration, and infrastructure
development have increased the anthrophony (sounds
generated by human activities), whereas the biophony
(sounds of biological origin) has been reduced by hunting,
fishing, and habitat degradation. Climate change is affecting
geophony (abiotic, natural sounds). Existing evidence shows
that anthrophony affects marine animals at multiple levels,
including their behavior, physiology, and, in extreme cases,
survival. This should prompt management actions to deploy
existing solutions to reduce noise levels in the ocean, thereby
allowing marine animals to reestablish their use of ocean
sound as a central ecological trait in a healthy ocean.

15.

Why This Year Is Our Last, Best Chance for Saving the Oceans
In fact, the underwater realm sounds more like an orchestra warming up,
the cetaceans hitting their high notes while other marine mammals clear
their throats against a background of breaking waves. A distant downpour
sends out a staccato riff that can be heard for miles, even as fish and marine
invertebrates snap out a syncopated rhythm designed to scare off predators
or attract mates. It is a cacophonous soundscape that had changed little in
tens of thousands of years. Until, that is, modern humans brought their leaf
blowers to the concert hall.
Over the past couple of hundred years, humans have progressively altered
the ocean soundtrack with the introduction of shipping, industrial fishing,
coastal construction, oil drilling, seismic surveys, warfare, sea-bed mining
and sonar-based navigation. Until recently, underwater sound pollution
had not attracted the same attention as its terrestrial equivalent. Now, a
new paper published in the journal Science titled “Soundscape of the
Anthropocene Ocean” lays out the repercussions, demonstrating that noise
pollution can be just as harmful to the ocean environment as other kinds of
pollution.

16.

Human beings owe their life to the sea
Four in 10 humans rely on the ocean for food. Marine
life produces 70% of our oxygen; 90% of global goods
travel via shipping lanes. We turn to the sea for solace—
ocean-based tourism in the U.S. alone is worth $124
billion a year—and medical advancement. An enzyme
used for COVID-19 testing was originally sourced from
bacteria found in the ocean’s hydro-thermal vents. The
ocean also acts as a giant planetary air conditioner. Over
the past century, the ocean has absorbed 93% of the heat
trapped in the atmosphere by greenhouse-gas emissions.
“If all that heat hadn’t been taken up by the ocean, we’d
all be living in Death Valley conditions by now,” says
marine-conservation biologist Callum Roberts at the
U.K.’s University of York.

17.

a powerful part of the solution
A revitalized ocean would not only feed a growing population
but could also strengthen our fight against climate change.
Coastal habitats such as mangroves and salt marshes are
extraordinary carbon sinks, sequestering as much CO₂ per
acre as 16 acres of pristine Amazonian rain forest. New
developments in offshore wind-farm technology can provide
an inexhaustible supply of green energy, while mineral
deposits on the seafloor, if mined sustainably, offer the raw
ingredients for the batteries to store it. “It’s time to stop
thinking of the ocean as a victim of climate change and start
thinking of it as a powerful part of the solution,” says Jane
Lubchenco, a marine ecologist who served as head of the
National Oceanic and Atmospheric Administration (NOAA)
under President Barack Obama.

18.

The stakes for ocean
The stakes for ocean health have never been higher. The
dying kelp and disappearing coral reefs should be
sounding an urgent alarm, says Christopher Trisos, a
senior researcher at the African Climate and
Development Initiative at the University of Cape Town
who focuses on the inter-section of climate change,
biodiversity and human well-being. “Bio-diversity loss
from climate change looks like a trickle right now, but it
could become a flood very quickly,” he says. Even greater
“catastrophic multi-species die-offs” could begin within
the decade, Trisos predicts, starting with tropical oceans
and spreading to tropical forests and temperate
ecosystems by the 2050s.

19.

the ocean has an extraordinary ability to regenerate.
But there are ways of preserving the ecosystems many
nations depend upon. Spanish-American marine
ecologist and conservationist Enric Sala has spent the
past 12 years surveying and documenting the ocean’s last
wilderness areas as a National Geographic explorer in
residence. Through his Pristine Seas project, he has
rallied governments to set aside 5.7 million sq km of
coastline and ocean as marine parks where fishing,
dumping, mining and other destructive industries are
prohibited. The results, he says, have been astonishing.
Even over a short time frame, he has watched depleted
fish populations grow sixfold, kelp flourish and coral
reefs bloom. Given the chance, he says, the ocean has an
extraordinary ability to regenerate.

20.

An international agreement to protect the oceans
would be a huge step—but it is only one tool, and an
expensive one. No amount of protection can block
pollution or plastic debris, or reduce temperatures.
Establishing marine protected areas is like taking an
aspirin for brain cancer, says Camilo Mora, a reefecology scientist at the University of Hawaii at
Manoa. “You think it’s working because the
headache goes away, but the tumor is still growing.
Unless we cut greenhouse-gas emissions, the threat
remains.”

21.

But the balance between sustainable use and
conservation of the oceans is delicate, and sometimes
fraught with complications. Deep-sea mining in the
Pacific Ocean, for example, could yield massive increases
in cobalt, nickel, copper and other materials essential to
meet the demand for clean-energy technologies and
batteries. The U.N.’s International Seabed Authority is
expected this year to codify environmental-protection
codes before allocating permits for the extraction of socalled polymetallic nodules. But environmentalists and
marine biologists are calling for a moratorium on
permits until more research has been done on these
deposits and their role in the ecosystem.

22.

Why the Ocean Matters
Covering 72 percent of the Earth and supplying half
its oxygen, the ocean is our planet's life support
system—and it’s in danger. Watch this video to learn
why a healthier ocean means a healthier planet, and
find out how you can help.

23.

With every breath we take, every drop we drink, we're
connected to the ocean. Our planet depends on the vitality of
the ocean to support and sustain it. But our ocean faces major
threats: global climate change, pollution, habitat destruction,
invasive species, and a dramatic decrease in ocean fish
stocks. These threats to the ocean are so extensive that more
than 40 percent of the ocean has been severely affected and
no area has been left untouched. Consequently, humanity is
losing the food, jobs, and critical environmental services that a
healthy ocean generates. National Geographic Society's
Ocean Initiative aims to restore health and productivity to the
ocean by inspiring people to care and act, reducing
the impact of fishing, and promoting the creation of marine
protected areas.

24.

Explorer-in-Residence
pre-eminent explorers and scientists collaborating
with the National Geographic Society to make
groundbreaking discoveries that generate critical
scientific information, conservation-related
initiatives and compelling stories.

25.

marine protected area (MPA)
area of the ocean where a government has placed
limits on human activity.

26.

What does the ocean have to do with human health?
Our ocean and coasts affect us all—even those of us
who don't live near the shoreline. Consider the
economy. Through the fishing and boating industry,
tourism and recreation, and ocean transport, one in
six U.S. jobs is marine-related. Coastal and marine
waters support over 28 million jobs. U.S. consumers
spend over $55 billion annually for fishery products.
Then there's travel and tourism. Our beaches are a
top destination, attracting about 90 million people a
year. Our coastal areas generate 85 percent of all
U.S. tourism revenues.

27.

Ocean in Distress
When we think of public health risks, we may not think of the
ocean as a factor. But increasingly, the health of the ocean is
intimately tied to our health. One sign of an ocean in distress
is an increase in beach or shellfish harvesting closures across
the nation. Intensive use of our ocean and runoff from landbased pollution sources are just two of many factors that
stress our fragile ecosystems—and increasingly lead to human
health concerns. Waterborne infectious diseases, harmful
algal bloom toxins, contaminated seafood, and chemical
pollutants are other signals. Just as we can threaten the health
of our ocean, so, too, can our ocean threaten our health. And it
is not public health alone that may be threatened; our coastal
economies, too, could be at significant risk.

28.

Closing the Safety Gap
Throughout the U.S., there are thousands of beach and
shellfish closures or advisories each year due to the
presence of harmful marine organisms, chemical
pollutants, or algal toxins. To address public health
threats and benefits from the sea, NOAA scientists and
partners are developing and delivering useful tools,
technologies, and environmental information to public
health and natural resource managers, decision-makers,
and the public. These products and services include
predictions for harmful algal blooms and harmful
microbes to reduce exposure to contaminated seafood,
and early warning systems for contaminated beaches and
drinking water sources to protect and prevent human
illness.

29.

Emerging Health Threats
Whales, dolphins, and other marine mammals eat much of the
same seafood that we consume, and we swim in shared coastal
waters. Unlike us, however, they are exposed to potential
ocean health threats such as toxic algae or poor water quality
24 hours a day, seven days a week. These mammals, and other
sentinel species, can shed important light on how the
condition of ocean environments may affect human health
now and in the future. As the principal stewardship agency
responsible for protecting marine mammals in the wild,
NOAA's Marine Mammal Health and Stranding Response
Program supports a network of national and international
projects aimed at investigating health concerns. This research
can not only warn us about potential public health risks and
lead to improved management of the protected species, but
may also lead to new medical discoveries.

30.

Cures from the Deep
Keeping our ocean healthy is about more than
protecting human health—it's also about finding new
ways to save lives. The diversity of species found in
our ocean offers great promise for a treasure chest of
pharmaceuticals and natural products to combat
illness and improve our quality of life. Many new
marine-based drugs have already been discovered
that treat some types of cancer, antibiotic resistant
staph infections, pain, asthma, and inflammation.

31.

5 Ocean Terms You May Not Know — But Should!
1. Tidal Bore
The name “tidal bore,” also called a “bore tide,” is a bit of
a misnomer — these natural occurrences are anything
but boring. Also called mascaret (French), pororoca
(Brazilian), and “the Bono” (Indonesian) — tidal bores
occur when the water in relatively shallow, sloping
estuaries or rivers moves as one massive solitary wave. In
order for a tidal bore to occur, the local tides must be
higher than average, and large amounts of water must be
concentrated as it flows down tight channels. Tidal bores
can reach up to 20 feet in height.

32.

This historic photograph shows a tidal bore in Turnagain Arm, a
waterway that flows into Cook Inlet, Alaska.

33.

2. Hadal Zone
Want to hear something that’s really “deep?” The
ocean is made up of five “zones.” The hadalpelagic
zone, commonly known as the hadal zone, is the
deepest part of the ocean, with depths ranging from
approximately 6,096 meters to 10,973 meters
(20,000 feet to 36,000 feet). Named after the Greek
underworld Hades, the hadal zone is made up of a
series of trenches, troughs, and deep depressions.
The hadal zone remains one of the least investigated
and most mysterious places on Earth. More than 400
species are now known to live in the 21 trenches of
the hadal zone.

34.

Cusk eels (family Ophidiidae) are common in the deep sea, like this one of the genus
Leucicorus.

35.

3. Mixotrophy
Most people think of life on Earth as being divided into
two categories: plants and animals. But that’s not always
the case. In the ocean, some single-celled, planktonic
algae, have the ability to photosynthesize like a plant and
consume other organisms like an animal. This hybrid
source of nutrition is called “mixotrophy.” A study from
NOAA’s National Ocean Service found that mixotrophic
algae may have an advantage in the formation of harmful
algal blooms — when algae grow out of control and
produce toxic or harmful effects on people, fish, shellfish,
marine mammals, and birds. The information from the
study will allow scientists to improve the models that
predict these dangerous occurrences.

36.

an example of mixotrophy

37.

4. Sneaker Wave
Sneaker waves can rapidly travel hundreds of feet up a
beach following long periods of quiet surf and smaller
waves, “sneaking” up on beachgoers and pulling them
into frigid, rushing currents, or causing rocks and logs
to dislodge and injure beachgoers. Sneaker waves
occur along much of the West Coast. In order to avoid
these dangerous waves, observe the water for at least
15 minutes before entering the water.

38.

A sneaker wave crashes on rocks on the Oregon
Coast

39.

5. Gravity Wave
Gravity waves, not to be confused with gravitational
waves, form when air is pushed up and gravity pulls
the air back down. On its way down, air displaces
ocean water, forming waves that look like vertical
channels. There are different types of gravity waves.
Gravity waves that form on the surface of the water
are called surface gravity waves. Waves that occur
inside of a body of water are called internal waves.
Waves created by wind on the surface of the water
are wind-generated waves.

40.

Aerial view of a gravity wave.

41.

How Healthy Are Earth's Oceans?
In a new perspective on ocean health, one that looks
through the lens of both humans and the natural world,
scientists give Earth's seas a grade of 60 out of 100,
meaning there's lots of room for improvement, they say.
The new index ranks oceans' health and the benefits they
provide to humans using 10 categories, such
as biodiversity, clean waters, ability to provide food for
humans and support of the livelihood of people living in
coastal regions
In addition to assessing the present, the index provides a
benchmark against which to measure progress in the
future, writes the research team led by Benjamin Halpern
at the National Center for Ecological Analysis and
Synthesis in California.

42.

The scores on individual goals varied by country
"The global score of 60 is a strong message that we are not
managing our use of the oceans in an optimal way," study
researcher Bud Ris, president and CEO of the New England
Aquarium said in a statement. "There is a lot of opportunity for
improvement, and we hope the Index will make that point
abundantly clear."
Countries' individual scores ranged from 36 to 86, with the Atlantic
coast of the west African nation Sierra Leone ranking the least
healthy, while the protected Pacific waters around Jarvis Island, an
uninhabited island designated a U.S. wildlife refuge ranked as the
healthiest.
In general, developed countries performed better than developing
nations, however, there were exceptions. Poland and Singapore
scored poorly, 42 and 48, respectively, while some developing
tropical nations, such as Suriname and Seychelles scored relatively
well, at 69 and 73, respectively.

43.

Here are the 10 goals upon which the ranking is
based
1) Food provision: This goal refers to the amount of seafood a
country catches or grows, all sustainably, from its waters.
2) Artisanal fishing: The opportunity for the small-scale fishing
efforts that are particularly crucial in developing nations.
3) Natural products: The sustainable harvest of living, non-food
natural products, such as corals, shells, seaweeds and fish for the
aquarium trade. It does not include bioprospecting, oil and gas or
mining products.
4) Carbon storage: The protection of three habitats, mangroves,
seagrasses and salt marshes, which store carbon, keeping it out of
the atmosphere and therefore mitigating global warming.
5) Coastal protection: The presence of natural habitats and barriers,
including mangroves, coral reefs, seagrasses, salt marshes and sea
ice, which physically protect coastal structures, like homes, and
uninhabited places, like parks.

44.

6) Coastal livelihoods and economies: Jobs and revenue produced
from marine-related industry, alongside the indirect benefits of a
stable coastal economy.
7) Tourism and Recreation: The value people place on experiencing
and enjoying coastal areas, not the economic benefit which is
included in coastal economies.
8) Clean waters: Whether or not waters are free from oil spills,
chemicals, algal blooms, disease-causing pathogens, including those
introduced by sewage, floating trash, mass kills of organisms and
oxygen-depleted conditions.
9) Biodiversity: The extinction risk faced by species as well as the
health of their habitats.
10) Sense of Place: Aspects that people value as part of their
identity, including iconic species and places with special cultural
value.

45.

WHAT NEEDS TO HAPPEN?
The pragmatic response is to cut carbon emissions as far and as fast as
possible, and at the same time, to fully protect very large marine areas to
help Ocean systems build resilience to the changes happening around
them.
There is more and more evidence that ‘blue carbon’ plays a critical role in
maintaining the health of our biosphere. This is the ability of mangroves,
sea grass beds, fish and marine mammals to play a huge role in
sequestering and storing carbon. By protecting and restoring these crucial
habitats and species, the more carbon will be sequestered and stored
resulting in a healthier planet, which is better for us all.
We also need to make sure that any extractive activities, like fishing or
mining, are sustainable, precautionary, and take account of their impacts
on the entire ecosystem, particularly in a time of change.
Studies have shown that coral reefs for example have a much greater
chance to recover from the effects of bleaching if other stresses have been
minimised or eliminated. For example, areas in no-take marine reserves
where fishing is prohibited have been shown to be more resilient

46.

OCEAN HEATING
In addition to changing chemistry, the Ocean is also warming. A paper in
the journal Science Advances (March 2017), outlines that the rate of Ocean
warming has quadrupled since the late 20th century, with increasingly more
heat finding its way down into the deep Ocean.
About 93% of all the excess energy trapped in the Earth system by manmade greenhouse gases goes towards heating the Ocean – compared to 1%
for the atmosphere.
If the same amount of heat that’ went into the top 2 kms of the Ocean
between 1955–2010, had gone into the lower 10 kms of the atmosphere,
then the Earth would have seen a warming of 36°C. We therefore owe it to
the Ocean that life goes on.
Ocean warming leads to a whole range of impacts on Ocean life, most
importantly the forced migration of marine species. The knock-on effects of
these changes cannot be underestimated: they threaten food security; the
very existence of coastal communities and the informal economies that
keep these communities intact. Furthermore, they will play a role in human
migrations as these changes impact on some of the most vulnerable peoples
around the world.

47.

DEOXYGENATION
Warming also leads to hypoxia – lack of oxygen – in parts of the
Ocean as it impacts on the microscopic plants that live in the Ocean
and are responsible for more than half the oxygen we breathe.
Oxygen loss from warming has alarming consequences for global
oceanic oxygen reserves, which have already been reduced by 2%
over a period of just 50-years (from 1960 to 2010).
Ocean regions with low oxygen concentrations are expanding, with
around 700 sites worldwide now affected by low oxygen conditions
– up from only 45 in the 1960s.
The International Union for the Conservation of Nature (IUCN)
warns that at a global-scale, warming-induced oxygen loss is driving
progressive persistent changes in nutrient cycling and recycling,
species distributions, marine ecosystem services and habitat
availability.

48.

Solving Humanity’s Grand Challenges Requires a Healthy Ocean
Human well-being and human rights are inextricably tied to the
health of the ocean, yet ocean conservation work is often isolated.
Last month, as the United National General Assembly focused on
tackling the grand challenges represented by the Sustainable
Development Goals (SDGs), both the ocean goal (aka Goal 14, “Life
Under Water”) and me, as a marine biologist, were a bit lonely.
At one event, guests were asked to put a sticker on their name tag
indicating the goal they most supported. Of course, I chose the
ocean goal: “Conserve and sustainably use the oceans, seas and
marine resources for sustainable development.” And until a
colleague arrived, I was the only one representing the ocean. What
was supposed to be a conversation starter turned me into a
wallflower. It was a poignant reminder of how misunderstood and
marginalized ocean conservation issues often are — and to our
global detriment.

49.

Healthy oceans equal healthy fish for the world’s poorest
Our oceans contribute to food security. Fish, shellfish and seafood
are key food categories for big parts of the population. However, if
not sustainably managed, fishing can damage fish habitats.
Ultimately, overfishing impairs the functioning of ecosystems and
reduces biodiversity, with negative consequences for sustainable
social and economic development. Based on an analysis of fishing
stocks, world marine fish stocks operating within biologically
sustainable levels declined from 90 percent in the mid-1970s to 69
percent in 2013.
What is particularly significant is that a decline in fish
populations poses greater risks for poor people in developing
countries. According to the United Nations, 820 million people do
not have enough to eat . 460 million of these people live in major
fish-dependent nations, countries like the Philippines, Indonesia,
and Mozambique. Seafood is their crucial source of healthy protein
and important micronutrients like iron, omega-3 fatty acids, zinc and
vitamins A and B12

50.

Healthy oceans equal healthy terrestrial ecosystems
Our seas and oceans have provided us with all these benefits while
at the same time absorbing large chunks of the environmental
implications our polluting activities have created. Since the
beginning of the industrial revolution, the ocean has absorbed about
one third of the carbon dioxide released by human activities,
thereby mitigating the full impact of climate change.
However, this comes at a steep ecological price. Greenhouse gas
emissions are increasing the acidity of the ocean and if we continue
business as usual, the ocean could become 150 percent more acidic
by 2100 [4]. This would be catastrophic for all ocean life as it would
lead to a reduction of plankton, threatening the survival of these
organisms and unique ecosystems.
Beyond climate change, our oceans protect coastal areas from
flooding and erosion. In fact, coastal and marine resources
contribute an estimated $28 trillion to the global economy each year
through ecosystem services. But there again, pollution of both land
and seas is a threat in many coastal regions.

51.

5 Ways to boost ocean health
Preserving the ocean wealth
Keeping our oceans clean
Improving coastal environments
Increasing ocean productivity sustainably
Reducing greenhouse gas emissions