SS4.09 Does Intentional Nutrient Fertilization (N,P And Fe) Foster C Sequestration and/or Increased Fish Fertilization?
Date: Tuesday, June 11, 2002
Time: 9:30:00 AM
Location: Colwood
 
JEPPESENE, National Environmental Research Institute, Silkeborg, Denmark, ej@dmu.dk
Søndergaard, M, , National Environmental Research Institute, Silkeborg, Denmark, ms@dmu.dk
Jensen, J, P, National Environmental Research Institute, Silkeborg, , Jpj@dmu.dk
 
SOLVING A GLOBAL CLIMATE CHANGE PROBLEM BY FERTILISATION: A CRITICAL VIEW FROM THE TOP OF THE HILLS OF ONE OF THE WORLD’S MOST NUTRIENT LOADED COUNTRIES
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Recently, it has been suggested that nutrient enrichment of water-bodies may help modulate the anthropogenically induced increase of CO2 concentrations in the atmosphere. Simultaneously, arguments are raised that a favourable side effect will be an increase in the production of fish. In lakes an increase in fish production certainly occur with fertilisation, but at high nutrient loading a shift occur to dominance of less attractive (for humans!) species. Biodiversity of the lakes show an unimodal relationship to nutrients being highest at intermediate nutrient concentrations. Fertilisation may therefore enhance biodiversity in oligotrophic lakes, but impoverish it on a global scale. Moreover, we demonstrate that fertilisation can be a risky business, once a lake has been eutrophied the way back can be very long. We discuss the implications of these lake findings for the perspective of intentional nutrient fertilisation of the sea. We finally argue that the problem of anthropogenically induced CO2 enrichment should be solved at the source by change of behaviour and by focusing on alternative energy sources rather than by fertilisation of waterbodies.