Industrial Toxics and Commercial Activities
Karachi has seven major industrial estates in
Korangi, Landhi, SITE, Federal B Area, North Karachi, Superhighway and Port
Qasim. For these estates, the coastal region of Karachi has become a dumping
ground for hazardous waste, receiving huge quantities of untreated domestic and
industrial wastewater through the Lyari and Malir river-channels. It is also approximated that 78 mgd
industrial wastewater is also generated by more than 6000 industrial units
operating in the city. Nearly 87% of this runs to the Arabian sea untreated as
majority of industries have no treatment facility. Huge amount of toxic metals
have been found in the city marine life including mercury, cadmium, chromium,
lead, arsenic and zinc. These metals are largely carcinogens and can cause
fatal diseases when consumed by humans.
Three main power plants like KANUPP I (Nuclear), Bin
Qasim I (Thermal) and Bin Qasim II (Gas} located at the Karachi coast also use
large amount of seawater for cooling while they discharge heated effluents and
other pollutants to the sea. Oil spills are one of the most alarming problems
of the coastal areas. Among the creeks of Indus delta, the Korangi and Gizri
creeks are the most affected from oil discharges from refineries, industries
and municipal activities.
Apart from this, the increased dumping of sewage and
industrial waste upstream of Indus River has decreased the quality of fresh
water flow to the sea and there is no fresh water input to the sea except the
local run-off from rainfall, which is minimal in Karachi.
The lengthy 70 KM coastline, which accommodates
Karachi Port and Port Qasim -- the busiest ports of Pakistan -- makes Karachi
the only home of shipping, sea trade and navel drills. However, ships and
fishing trawlers through their discharges, wastages water pollution, and oil spillages
also affecting the coastal environs, besides severely contaminating the
mangrove forests and marine life in the sea.
The ports authorities are ill equipped to deal with the environmental
degradation being caused by the shipping sector.
The country' heavy dependence on oil imports is also
chipping in it as majority of cargo ships transit oil to the Karachi' ports.
And, it is believed that thousands of tons per year oily discharges are pumped
out within the port limits and there isn't any waste oil receptor or treatment
facility available within ports.
Mangroves
Mangrove forests are significant in balancing
coastal ecosystem and bridging between terrestrial and marine environments.
They transfer organic matter and energy from land to the sea, forming the base
of many marine food webs. Mangroves are the first natural wall of defence
against natural calamities including cyclone and sea level rise as they are
vital in trapping sediments, thereby stabilising coastlines and protecting
coral reefs and sea grass meadows. They are also important to stabilise
shorelines, reduce coastal erosion, protect coasts from storm damage and act as
carbon sinks and natural water treatment plants.
Pakistan coastal belt is heavily dependent on these
mangroves forests to maintain the ecological balance. Besides a source of
nutrients, the mangroves provide a diverse habitat for complex and
interdependent community of invertebrates, birds and reptiles. However the growing
dependency of coastal communities on mangroves for fuel and fodder for their
livestock and camels and unchecked mangroves deforestation, misbalancing the
marine ecosystem . Mangroves forests are
being continuously degraded further by decreasing fresh water discharges. This
degradation is resulting in the loss of important breeding and spawning grounds
for marine fisheries.
Nearly 125,000 mangrove trees were planted over last
25 years in different coastal areas of Sindh, with survival ratio of 70%. But
release of fresh water that also carries nutrient-rich slit and deposits it
into the sea is pre-dominant cause of the rapid worsening state of the mangroves
forests and is a stumbling block to the growth of new mangroves trees.
Ecologists therefore recommend strong check on
mangroves deforestation through laws and strict control of coastal development
besides reforestation of denuded areas to recover the mangroves loss caused
over decades. Raising and protecting mangroves forests also require sweat water
through Indus river -- a minimum 10 million acre feet fresh water discharge
into the delta is suggested for sustainable management.
Biodiversity
Karachi coastal areas are also home to species and
habitats that provide many benefits to society and natural ecosystems. It's
wetlands attract a number of migratory birds, particularly waterfowl. Two
species of turtles -- the Green turtle and Olive Ridely turtle -- are also
found in the shores of the Karachi coastline.
However, these coastal areas are now vulnerable to
climate change, which could affect in variety of ways and bring cyclone and cause
heavy devastation of life and property. Coasts are sensitive to sea level rise,
changes in the frequency and intensity of storms, increase in precipitation and
warmer ocean temperature.
The impacts of climate change are likely to worsen
many problems that coastal areas already facing. Shoreline erosion, coastal
flooding, and water pollution affect man-made infrastructure and marine
ecosystems. To confront these challenges is already a concern, yet the
additional stress of Climate change definitely require modern and global
approaches to managing land, water, waste and ecosystems.
(To be concluded)
By
Editorial, Infocus
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