Bioindicators individuals

Environmental Cancer Risk, Nutrition, and Individual Susceptibility (ECNIS) Studying use of biomarkers of exposure and susceptibility and bioindicators of disease in molecular epidemiology of cancer (ECNIS 2005). 

Krill is a small planktonic crustacean primarily living in the Southern Ocean and its total biomass is estimated to be at least 500 million tons (around 500,000 billion individuals). It feeds on phytoplankton and is one of the most important species in the Antarctic food chain. In fact, krill is the basic food for whales, seals, cephalo-pods, penguins and many other seabirds and is also used for direct human consumption (20-24). Moreover, krill seems to be a promising bioindicator of environmental pollution by trace elements and organic compounds. All these considerations called for the production of a CRM for trace elements based on this matrix (25). 

The domination of the exogenous way with regard to most of the elements causes also that feathers of migratory or nomadic birds can not be applied for this kind of bioindication studies. Analysis of feathers ought to be limited to settled bird species or young individuals of other species but still remaining within the breeding territory of their parents. 

Transposition of results of feather analysis to internal tissues is one of fundamental topics with regard to an application of magpie feathers as bioindicators of heavy metal pollution. This appears to be very limited because of different origin of incorporated heavy metals a dominance of exogenous deposition in feathers and endogenous way with respect to the internal tissues. Fig. 8 compares merits and demerits of the analysis of discussed tissues - a scatter of results regarding individuals of different age from a single study area (arrows 1), a reflection of pollution variabilities between areas (arrows 2) and a transposition of feather data to internal tissues (arrow 3). 

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