Marine Environment
The
oceans are home to half the world's biodiversity and is the source of their
livelihood (fishing, whaling, or tourism) for many. Ocean water and ice make up
almost 98 percent of all the water on Earth. The oceans are home to innumerable
species that we are now only beginning to discover. However, the threat to
oceans and marine life is often overlooked. Some of them include:
1. Ocean Dumping
Dumping of waste materials from industries, ships and sewage plants into
oceans has polluted the marine ecosystem to a great extent. The oceans have
been the dumping site of sewage, chemicals, industrial waste, garbage, and
other debris from the land. According to reports, only mining companies across
the world dump million tonnes hazardous waste directly into our waterbodies
every year. Around two-thirds of the marine lives in the world have been under
threat from the chemicals we use every day, including household cleaners. The
adverse effects of ocean dumping affects humans also as it poses health risks.
2. Land Runoff
One of the major sources of ocean pollution is the waste comes from the
nonpoint source, which happens as a result of runoff. Surface runoff from both
agricultural land and areas carry soil and particles mixed with carbon,
phosphorus, nitrogen and minerals, posing threat to the marine life. Water
filled with these toxic chemicals land in the ocean, resulting in harmful algal
blooms. This kind of water pollution threatens the species of fish, turtles,
and shrimp etc. and also humans through the food chain.
3. Dredging
Dredging is an important activity that enhances marine transportation
and other related activities. However, dredging has been a major cause of
disturbance in the marine ecosystem for many years. As dredging is to remove
the deposits submerged underwater, the activity alters the pre-disposed
composition of soil, leading to the destruction habitat of creatures and
organisms. Similarly, dredging of contaminated materials will result in the
regrouping of harmful particles and contaminate large of areas of water bodies.
Several cases involving the destruction of underwater lives are extensively reported
4. NOx and SOx
Nitrogen oxides (NOx) and Sulfur oxides (SOx) – the two main pollutants
found in shipping emissions- has badly affected both marine environment and
ozone layer in a number of ways. Both NOx and SOx are combustion products that
are emitted into the environment in the form of smoke. These type of air
pollution causes premature deaths of aquatic life
5. Ocean Acidification
The issue of ocean acidification is quickly becoming a threat to both
marine lives and humans. Ocean acidification is the continuing decrease of
seawater pH caused by the absorption of carbon dioxide (CO2) from
the atmosphere. Ocean acidification has the power to endanger the lives of
marine organisms and also humans who depend on fish and fish products for their
daily sustenance. Studies have shown that the decreased pH levels affect the
behaviour of several marine species, putting them at life-threatening risks.
6. Sea Water Level Rising
Global warming is alarmingly increasing seawater levels, threatening the
marine ecosystem. According to reports, the annual rate of seawater rise during
the past two decades has been 0.13 inches a year, which is around twice the
average speed of rising over the preceding 80 years. The rise in seawater level
means more wetland flooding, destructive erosion and agricultural land
contamination and more importantly a serious threat to the habitat of several
plants, fishes and birds. It is high time that we understand about the causes
and effects of seawater level rising to save the marine environment and
biodiversity.
7. Ozone Depleting Substances
Ozone-depleting substances such as CFC’s and Halon along with other
pollutants from ships destroy the ozone layer. Ozone Depleting Substances
omitted by ships across the world include Methyl Chloroform, Methyl Bromide,
Bromochlorodifluoromethane and Bromotrifluoromethane etc. These man-made gases
are capable of destroying ozone and in effect, these gases causing harm to the
marine environment in several ways.
8. Waste Pollution from Ships
Ships are another major source of pollutants such as oil and gas and the
waste and garbage generated on board ships poses a significant threat to the
marine ecosystem. Both solid and liquid waste in form of food waste, packing
material, paper products and cleaning material and rags etc. pollutes the
seawater and badly affects marine lives. The vessels used for various purposes-
a container or cruise ship- contribute to this pollution in different levels.
9. Noise Pollution from Ships
The noise generated from shipping operations is harmful to marine
organisms. Harmful effects of noise pollution on marine organisms include
haemorrhages, changed diving pattern, migration to newer places, and damage to
internal organs and an overall panic response to foreign sounds. Source of
noise pollution from ships include engine noise and the entertainments in
cruise ships. The intensity of noise pollution is higher in marine environment
since noise travels greater distances easily in water. Marine life is extremely sensitive to noise
due to their heavy reliance on underwater sounds for basic life functions.
10. Oil Spills
The biggest cause of marine pollution – oil spills. The world has
witnessed several oil spill disasters that have been one of the major concerns
of pollution to the marine environment. Disasters such as the Exxon Valdez Oil
Spill and Deepwater Horizon etc. have resulted in the extreme pollution of the
marine ecosystem, killing thousands of marine species. The oil spilt destroys
the insulating ability of several marine species and also the water repellency
of bird’s feathers, exposing these creatures to life-threatening risks.
Plastic Pollution
is the reason for several environmental problems both at sea and land. Pacific
garbage patch (collection of marine debris in the North Pacific Ocean) is a well-known example
of the extent of damage plastic is causing to the marine environment. It is
estimated that around 8 million tonnes of plastic waste enters our oceans every
year, and by 2050, at this rate, it is estimated that there will be more plastic
than fish in the water bodies across the world. The plastic pollution has a
direct effect on wildlife as it- plastic bags, fishing nets and other
debris-chokes tens and thousands of seabirds and sea turtles every year. The
ingestion micro plastics by fish and other species also pose risk to their life
as well as humans.
Pacific garbage patch
12.
Nuclear waste threaten our oceans
When
humans step in, the threat to the natural habitat comes not only from their
actions but also from the after-effects of it. There is a real threat from
nuclear waste leading to radioactivity, and now it has been reported that
radioactive lobsters are found in the Irish Sea
13.
Threatened Oceans mean threatened Corals
Along
with the ocean water, a high percentage of the world's coral reefs are at risk
of degradation. High acidity in the ocean water caused by pollution, oil
spillages, sedimentation and disturbances to habitats are threatening the
wonderful world of the coral reefs. Measures include planning, management, law enforcement,
environmental education, and legal protection to restricting development in
sensitive coastal areas Australia's Great Barrier Reef, the largest reef in the
world, illustrates the potential of careful reef management.
Management strategies to save ocean
include
1)
Research
and education to increase public appreciation of biodiversity and the impacts
of human activities.
2)
Avoid
practices such as overfishing, resource exploitation and
3)
Decision
makers must implement appropriate and effective legislations
4)
Marine
reserves are reference areas with minimal human impact, and help to reduce changes
caused by human actions. Reserves allow scientific education and ecotourism
activities impossible in fished areas. Overfishing is eliminated. Reserves can
be used to improve public awareness and understanding of natural systems and
human impacts on those systems. Thus they address many issues that often are
not adequately treated by traditional management approaches. Marine reserves
are an essential element in ecosystem management and offer considerable
potential for protecting and restoring marine biodiversity.
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