Page 23 - Professorial Lecture - Prof Omoregie

 Several of the light weight polycyclic aromatic hydrocarbons (which are
water soluble) remain in the water column even after massive clean-up
(Omoregie & Ufodike, 2002 and UNEP, 2006).

Direct Habitat Modification / Destruction by Human Activities
• This is becoming a major threat to marine life. Several human activities
contribute to the alteration of marine substratum. Major causes include
bottom trawling and mining of resources from the bottom of the sea.
• Apart from changing the bottom ecosystem, gases and other materials
naturally locked within the substratum are released into the water
column with the devastating effect of pollution of the water column 
great threat to biodiversity.

Bioavailability of chemical Contaminants to Fish and other aquatic organisms

An important aspect of bioavailability of contaminants to fish and other
organisms in the environment in the chain of events is chemical speciation
(existence of chemicals in different forms) as a result of chemical and biochemical
reactions of these chemicals (methylation).

The identities and relative concentrations of chemical species vary with locations
and time and also differ among the various components of an aquatic ecosystem.
A fish can be exposed to a mixture of chemical species both in the water and from
the food it ingests.

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