Oceans are
extremely pristine. The oceans are essentially one of the biggest resources for
life on earth, but at the same time, one of the biggest dumping grounds. Globally,
more than three billion people depend on our oceans and coastal ecosystems for
their livelihood. One would think that humans would be more respectful to the
ocean, considering that it's a vital source of nutrition for these people. Our
gorgeous oceans and their inhabitants are often taken for granted. Our ocean generates 80% of the oxygen we need
but the carbon levels in the oceans are at an all-time high. Unfortunately
oceans are faced with several far-reaching threats. People sometimes wrongly
view the ocean as bottomless and a convenient dumping ground, it’s seen as an
inexhaustible supply of food, a useful transport route, immune to all the
impacts from people and thus too vast to be affected by humans’ impact but
these careless actions have detrimentally affected marine ecosystems. Natural
disasters result in temporary destruction of habitat. However, human impacts
are more consistent and severe.
The ocean has
been irreversibly damaged as a result of these human-induced impacts and unprecedented
environmental changes have occurred. The world's oceans are significantly
affected by human activities — and few ocean areas remain untouched. Sadly, humans
will continue to inflict harm on the ocean, both through day-to-day activity
and episodic events like major oil spills. Moreover, scientists have begun to realize these devastating effects on the oceans. As a result of not properly
protecting the ocean, over-fishing, by catch, pollution, and other issues have
become major threats to the health of our oceans. We have disrupted marine ecosystems
everywhere and have driven countless species towards extinction. Thus not only
are the marine habitats and species being threatened, it but also our own
health, way of life, and security. Even though global fish populations provide
a critical source of food for millions of people around the world, they are
rapidly declining. Plastic and toxic waste also end up in oceans. Because
there’s less than two per cent of our oceans set aside as marine reserves, it
has become way too easy to exploit their natural resources. Even though 71% of
our beautiful planet is covered by oceans, they are still severely neglected,
which, in turn, is harming the innumerable creatures that live in them, and
polluting one of our largest resources.
Here’s a look at
the most prominent and extensive threats:
Overfishing & Destructive Fishing
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| Source: Venngage |
One of the most
noticeable threats is overfishing. Marine scientists consider overfishing to be
the worst impact humans are having on the oceans. We’ve now almost emptied the
oceans. We have systematically depleted the fish in our oceans. It has
environmental and social consequences. Socially, it threatens food security for
millions of people around the world and, environmentally, it destroys ocean
ecosystems all over the world. By capturing fish faster than they can
reproduce, people are essentially harming an entire ecosystem that interact
with those species, from the food they eat to the predators that eat them. Two
shocking facts are that we have already lost two-thirds of the large fish in
the ocean and one in three fish populations have collapsed since 1950. 90% of
the world's fisheries are already fully exploited or overfished, while billions
of unwanted fish and other animals die unnecessarily each year. In fact, unsustainable
fishing is the largest threat to ocean life and habitats. Previously, people
caught fish with small boats and rods close to the shore. And then people exhausted
the pelagic fish (including herring and tuna). Further, then, people went
deeper, catching species, which can live to 150 years and don’t breed until
they are 20 years old. People use destructive methods in
how they pull catches, such as bottom trawling which destroys sea floor habitat
and scoops up many unwanted fish and animals that are tossed aside. They also pull far
too many fish to be sustainable, pushing many species to the point of being
listed as threatened and endangered. These losses inevitable make the
ecosystems more vulnerable to other disturbances, including pollution. Overfishing’s
impact relates to wiping out a species, as well as other species of marine
animals that are dependent upon those fish for survival. Not only that but it
can cause marine animals to starve because people take food from their mouths
in too large of numbers for them to be able to get their fill. Knowledge is
power. Thus, it is important for people to properly know what types of seafood
can be sustainably eaten, whether that is the species of seafood or the method
by which it is caught. This will then ensure that the ocean's fisheries are healthy.
As a result of technological advances of the last few hundred years, it has
resulted in unsustainable levels of harvest, threatening fish stocks and the
integrity of entire marine ecosystems. Thus, it not only has ecological
impacts, but declining fisheries also result in economic loss and decreased
food security. Furthermore, ghost fishing is an environmentally harmful issue. It
is caused when lost or discarded fishing gear continues to catch fish and other
marine life. The traps frequently trigger a chain-reaction problem when larger
predators come to eat the smaller ones that have been ensnared, only to get
tangled themselves. It commonly occurs when passive gear has been abandoned. It
also poses a serious threat to other ocean vessels.
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| Source: Oceana |
Pollution
While carrying
serious consequences, oil spills and other pollution at sea, account for a
small fraction of ocean pollution. Approximately half of all ocean pollution
comes from land-based activities, like sewage, industrial and agricultural
runoff, garbage dumping, and chemical spills. Pollutants from land, including
plastics, untreated sewage, garbage, pesticides, industrial chemicals, and
fertilizers, frequently end up in the oceans, either by deliberately dumping it
or it enters from water run-off and the atmosphere. Moreover, this careless
action is harmful for the entire marine food chain with undesirable
consequences. One aspect of pollution that detrimentally affects the ocean is
major oil spills, periodically causing major incidents. People are still
dependent on the ocean to dilute agricultural and sewer runoff. The ocean is the
world’s largest “sink”, absorbing about half of the CO2 created by burning
fossil fuels and how we manage the ocean can increase that natural absorption
rate.
This is one of the most noticeable
threats. It’s
shockingly astonishing to see how much of our trash finds its way into the
ocean. Because plastic is so durable (it
can persist in the oceans for tens of thousands of years), it has significant
ecological impacts as it resists the pull of time and bio-degradation that
return most materials back into biologically useful forms. People’s use of
plastic has risen, and also, simultaneously, the amount that has been dumped,
blown, tossed, or dropped into the world’s oceans and rivers. For example, a
Pacific Ocean Garbage Patch exists which is an area in the Pacific Ocean
between the West Coast of America and the Hawaiian islands that, due to the
circular ocean currents surrounding it, collects and aggregates plastic waste. Worryingly,
there are places within the garbage patch that have more plastic than plankton.
Plastic in the waters leach chemicals and are frequently mistaken as food by
marine wildlife. Marine debris endangers human health and hurt business and
tourism by dirtying our beaches and coastlines. An estimated 60-80 per cent of
all marine debris originates from land-based sources. Human industry is
responsible for dumping an ever-growing amount of trash and pollution into
oceans. Over-consumption has led to pollution. The oceanic environment and its
wildlife are severely choking on plastic. All plausible solution for this is to
stop pollution at the source. Animals become easily entangled and trapped in
our garbage, and it can destroy delicate sea life such as coral and sponges. Sea
turtles and dolphins often mistakenly see plastic bags as their favorite foods, jellyfish and squids, choking them or clogging their digestive system. Pollution
from the land is creating oxygen-deprived dead zones where plants and animals
can’t survive. Plastic debris revolves around gyres in the world’s oceans: two
in the Pacific, two in the Atlantic, one in the Indian Ocean.
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| Source: Unknown |
Climate
Change
The temperature
rise over the past century is estimated at about 0.1 degree Celsius – that’s
enough to kill the algae that keep corals alive, move species into new areas,
and cause sea levels to rise. It is actually getting warmer faster than
predicted. The effects of climate change would continue to play out for a
century, even if people stopped pumping additional carbon dioxide into the
atmosphere. Global warming is essentially creating a climate time bomb by
storing enormous amounts of heat in the waters of the north Atlantic. Climate
change is caused by the release of greenhouse gases (GHGs) into our atmosphere
– primarily caused by the burning of fossil fuels. Fossil fuels, such as
petroleum and coal, release carbon dioxide that traps heat in our atmosphere. Warmer
waters would receive less protection from sunlight, which would warm them further.
Heat stored in the oceans could be released into the atmosphere in the future, lessening
efforts to stabilize global temperatures with cuts in man-made greenhouse gas
emissions. Warmer air and water temperatures result
in loss of sea ice, sea level rise, ocean acidification and extreme weather.
All these aspects threaten fish and wildlife populations as well as our quality
of life.
Acidification
Acidification relates to carbon dioxide, dissolving in oceans to form carbonic acid. The greater the acidity, the less able marine-calcifying organisms are to form shells which disrupt their reproductive process. Oceanic acidity has increased by 25% since the industrial revolution. It will eventually destroy much marine life if it increases at this rate. In the future, there will be a tipping point where the oceans become too acidic to support life that can't quickly adjust. Thus, many species will go extinct, from shellfish to corals as well as the fish that depend on them.
Habitat destruction and degradation
Another way in which ecosystems (which
marine plants and animals need for their survival) are systematically
destroyed, include clearing mangrove forests for shrimp production and scraping
entire ecosystems off seamounts, or underwater mountain ranges via deep-sea
trawling. Furthermore, fields of dying coral occur, and the sea grass and
mangrove forests get whittled away by human development, wind, and sea.
Inadequate
Protection
Even though,
oceans cover over 70% of our planet’s surface, only a tiny fraction are protected: just
3.4%. More and better managed Marine Protected Areas are urgently required.
Else, the future of the ocean’s rich biodiversity remains uncertain.
Tourism
& Development
All over the world, coastlines have
unfortunately been gradually turned into new housing and tourist developments. Unrestricted
coastal development is severely impacting wetland and coastlines. As a result
of this intense human presence, it has taken a toll on marine life.
Shipping
Because the oceans are huge “highways”
where people ship all kinds of goods. But due to the heavy traffic, it has left
a lasting mark: oil spills, ship groundings, anchor damage, and the dumping of
rubbish, ballast water, and oily waste. All of these factors are endangering
marine habitats around the world.
Oil & Gas
Important reserves of oil, gas, and
minerals lie deep beneath the seafloor. But, prospecting and drilling poses a key
threat to sensitive marine habitats and species. When oil is extracted from the
ocean floor, other chemicals like mercury, arsenic, and lead come up with it. Furthermore,
the seismic waves used to find oil harm aquatic mammals and disorient whales.
Aquaculture
Many times, the farming of fish and
shellfish harms wild fish, through the pollution the farms discharge, escaped
farmed fish, increased parasite loads, and the need to catch wild fish as feed.
Invasive species
Most aquatic
invasive species are spread by human activities such as shipping or the
aquarium trade. Once invasive species have been introduced to a new
environment, it can negatively impact the environment, economy, and human
health, and threatening native ecosystems and biodiversity.
Commercial Whaling
This is still a
concern nowadays. The shocking practice was rampant for such an extensive
period, that, sadly, many whale species may never recover.
Conclusion
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| Source: Greenpeace |
It’s clear that
as a result of human activity, especially over the last few decades, it has
undoubtedly pushed oceans to their limit. One thing is for certain: the largest
living space on Earth is fast deteriorating. Urgent strategies are required to
deal with it, and to reduce other pressures on marine habitats already stressed
by these factors. The health of our oceans should be a top priority, in the
fight for the environment.
References
http://thankyouocean.org/threats/
