Oceans cover over about 70% of the
earth surface. Therefore the majority of world’s biodiversity claims to the
ocean. Also marine ecosystems play an important role in good and service
supply. Human food security highly depends upon the marine ecosystems, because
a large portion of human protein requirement is supplied by the oceans.
All the continents are linked by the
oceans. All terrestrial inputs are finally gathered to the oceans via the river
out puts. If any problem will occur in any oceanic area, impact directly or
indirectly to other areas. Therefore “the threats to marine biodiversity” is a
topic should be concerned and discussed internationally.
Over fishing is a one of major
problems in the oceans. As a result of unsustainable fishery world fish stock
has depleted. Not only fish but also other marine species including
invertebrates and mammals are threatened by unnecessary fishing methods. This
is affecting to reduce the marine biodiversity as well as world food security.
Some species are already extinct and some are going to extinct since the over
exploitation.
Another threat is habitat
degradation. Utilization of unnecessary fishing gears is a reason for that. Usage of dynamite to catching fish, coral
mining, destroying the mangrove lands are also caused to that. Drilling the ocean
bottom to crude oil is another reason. As result of the habitat degradation,
migration patterns of the migrant species such as turtle can be changed or
disturbed. Also the breeding and hatchery lands can be destroyed and it may
cause to break their reproduction. When someone’s native habitat is damaged, it
has to adopt for a new habitat. But it is not an easy task. Sometimes it may be
able to survive or has to be extinct from the environment.
With the industrial development and
the population increase, lots of pollution agents are released in to the
environment. Polythene and plastic are great threat to the environment. Also
lot of chemicals and heavy metals are released from the industrial waste
outputs. Pesticides, weadicides and insecticides are highly used in
agriculture. All of these pollutants finally added to the oceans. Some of them
are toxic. They are concentrated via the
food chains (bioaccumulation). Some are
caused to destroy the habitats. Addition of the swages and garbage in to the
oceans is another problem. It causes to eutrophication. Also it is damage to
the corals because it provides more organic nutrients while corals prefer
nutrient poor water. Oceanic oil splits is another risk.
As a result of the anthropogenic
activities the world climate has changed. Ozone depletion, greenhouse effect
and global warming are the major current issues. It causes to melt the
glaziers, and to increase the sea level. Coral bleaching, hatchery
disturbances, sex transferring can be occurred with the increase of the sea
temperature. It also affects to the oceanic current systems and the survival of
the ecosystems.
Invasive species is another threat.
Introduction of alien species can be occurred with or without human impact.
Some organisms such as mollusks attach with the marine transport vessels and
travel from ocean to ocean. Then they can inhabit to new oceanic environments.
Not only macro organisms but also micro organisms can become invasive species.
Invasive species can be predators or parasites. Also they may spread diseases.
As a result of invasive species inter specific competition can be occurred.
Hybridization is another result. It causes to damage the gene diversity.
Marine biodiversity needs our help to
overcome these threats. Conservation plans should be established to protect the
marine biodiversity. There is a less knowledge about marine and coastal
conservation in publics. So awareness programmes should be launched. Also there
is a lack of human resource in marine conservation sector. Therefore the
academic programmes should be improved and students should be encouraged and
motivated.
These threats can be reduce via the
well planned short term and long term policies. Introducing the policies to the
sectors such as tourism, fishery industry, other coastal industries, coastal
residence, transport, and out loading of swages and garbage is very important.
Governments and other responsible institutions and organizations must directly
mediate to that. Sustainable utilization of marine recourses and reduce the
ocean pollution is the best solution. Continuous monitoring, evaluating and
treating processes are important.
Oceanic problems not only belong to
one country. Therefore international policies should be established. Whole
world should get-together to solve that problem. That is problem which can’t solve only by
lows and legislations. Everyone should make a self change in attitudes about
conservation of marine biodiversity.
We should get hand in hand to protect
marine biodiversity because that is our responsibility to serve the Mother
Nature. So let’s get aware and identify the threats and take correct actions as
soon as possible to avoid the threats since “prevention is better than
cure”.
