How many individuals of a certain population do we need to preserve?

This question is well worth further consideration...

Concepts like Population Viability Analysis (PVA) and Minimum Viable Populations (MVP) have been developed to address this question. The main reasoning behind those concepts is to provide guidelines on how to avoid extinctions of a target species. However, interactions among species have seldom been incorporated in such analyses. Further may the reduction in population size of one single species, in the worst case lead to extinctions of other species within the community.

Consider the classical example illustrated to the right of this text. (a) Sea otters are abundant; ensuring a healthy ecosystem with a normal level of sea urchins grazing on the kelp bed. (b) Sea otters are reduced, thus giving rise to a released predation pressure on sea urchins, whom in turn over grazes the kelp bed.

Is there a threshold above which the sea otters needs to be maintained in order to avoid this kind of devastating consequences? 

This question exemplifies the main idea with my master thesis. ie. How large must the population of a certain species be in order to avoid extinctions of other species within the community?

By the use of mathematical models and computer simulations have I during the master thesis developed a method of estimating Minimum Ecological Viable Populations (MEVP); earlier defined as " the minimum size of a population that can survive before itself or some other species within the community becomes extinct".The MEVP:s were compared to the traditional conservation measure Minimum Viable Population (MVP).

Find out more about the thesis or take a look at my Leaflet and Poster presentations.

Enjoy!!!