Thiruvananthapuram, Oct 3 (IANS): A noted US environment scientist Thursday stressed the need for exercising prudence in the use of natural resources warning that while populations grow, natural resources do not.

Claude E. Boyd, noted aquaculture, fisheries and environment scientist from the US, told the inaugural function of the three-day ECOCASD 2013 International Conference here that there was "a need for the human race to be more prudent in optimising the use of natural resources".

The veteran scientist also pointed to the decline of marine biological resources because of unabated pollution, which was aggravated by climate change.

Over 500 delegates, comprising scientists, teachers, researchers and students, are taking part in the event.

The event, held for the first time in Ethiopia, is having its second leg at Kerala University here.

With the theme of ecosystem conservation, climate change and sustainable development, ECOCASD 2013 is expected to open debates on environmental issues.