Page 20 - Professorial Lecture - Prof Omoregie

 Introduced dangerous metals include mercury, lead, and copper
 Human activities release 5 times as much of mercury and 17 times as much
of lead as is derived from natural sources.
 Contaminated land runoff, rain of pollutants from the air, and fallout from
shipwrecks pollute the ocean with dangerous metals
 Fuel combustion, electric utilities, steel and iron manufacturing, fuel oils,
fuel additives and incineration of urban refuse are the major sources of
contamination by heavy metals
 On a global scale, water pollution has increasingly threatened production in
some newly industrialized and rapidly urbanizing areas. In 2010, aquaculture
in China suffered fish production losses of 123,000 tonnes as a result of
water pollution (FAO 2012b).
 Radioactive metals from nuclear plants constructed along coastlines: a good
and recent example is the release of radioactive materials from the
Fukushima Nuclear Plants in Japan. The contaminated Pacific Blue-fin Tuna
after the nuclear disaster carried the radioactive metal cesium-137 across
the entire North Pacific Ocean as reported by US researchers in the Cosmos
Magazine of 29 May, 2012.
 Heavy Metals are a great concern because they enter the food chain and
eventually get to humans
o Copper is dangerous to marine organisms and has been used in marine
anti-fouling paints
o Mercury and lead poisoning cause brain damage and behavioral
disturbances in children. These constitute major effluents from several
industries

Major Marine Pollutants – Solid Waste
 A large portion and great danger is the non-biodegradable hydrocarbon
plastic materials (which constitute the bulk of solid waste)
 Research has shown that it takes over 400 years for the commonly used
plastic packaging materials to start the process of decomposition
 Over time, several inorganic chemical components of the plastic leach
into the surrounding water, thereby increasing the levels of these
chemicals leading to direct poisoning of the biota

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