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Marine Pollution ...

Transportation - Based Pollution. It constitutes dumping of bilges in the form
of direct discharges into open sea. In Bangladesh, starting from a tiny country
boat to large merchant vessels takes chances and disposes their garbage and
bilges into the sea. Gases (which dissolve at sea), chemicals and sewage from
container ship are also another major source of pollution at sea.
Accidental Pollution. The accidental pollution most often results in release of
huge amount of liquid petroleum into the ocean. Most often it relates to rapture
of hull due to collisions, groundings, fires/ explosions, excessive list, failure of
containment system etc from ship and off-shore gas /oil rigs.

Conceptualizing Impact of Marine Pollution
One clear link between sewage disposal and marine environmental problems is
related to the consumption of contaminated seafood, seaweeds medicine and
usable waters. Polluted water cause reaction and mortality to mangrove trees and
damage eco-system including nursery ground of marine fish and crustaceans in
swamps. Fish are capable of accumulating a variety of pathogenic organisms
from eating plastics and contaminated water. If consumed by human will have ill
effects. Crude oil makes a layer on water surface which prevents the penetration
of sunlight. As a result, the dissolved Oxygen (DO) and Biological Oxygen
Demand (BOD) decline dramatically. Tanker spills are an increasing
environmental problem because once oil has spilled, it is virtually impossible to
completely remove or contain. Even small amounts spread rapidly across large
areas of water, because oil and water do not mix and the oil floats on the water
finally reaching to shoreline. Attempts to chemically treat the oil may further
disrupt marine and beach ecosystems. The most disastrous consequence of oil
spill is the social unrest resulting intense media attention and political uproar,

Figure 3: Conceptualizing Impact of Marine Pollution

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