Harvesting Biological Populations

Abstract

Biological populations, both of plants and animals, constitute a very important resource for mankind. Moreover, unlike minerals or fossil fuels, plants and animals are a renewable resource. It replenishes itself automatically after being harvested. Hunting, fishing and gathering forest produce are among man’s oldest professions. Practitioners of these professions have always assumed implicitly, that whenever they go looking for more of the resource, it will be there. Perhaps this was the case when the rate of exploitation was low because of smaller human population size and primitive technology. Today this assumption that biological resources are unlimited is definitely not valid. Forest cover is declining in many countries at an alarming rate because timber is harvested at a rate faster than its growth. Yields of fisheries seem to go down in spite of ever increasing fishing effort because increasing number of trawlers have to chase decreasing number of fish. In India, male elephants with tusks are harvested (poached) for ivory. This has caused a steep decline in their numbers. Tigers are killed for their skins (for display) and bones (for medicine) in excessive numbers and hence face extinction. Similarly Ginsberg and Milner-Gulland (1994) have expressed fear that excessive trophy hunting of male impala in Africa may cause a collapse of that population.