Population dynamics, predation and role in the community

Abstract

Studies on the population dynamics of esocids, in particular pike, Esox lucius, have greatly increased the understanding of general fish population dynamics. This is especially the situation in simple aquatic systems, 'simple' relating to low numbers of fish species present in the community. In a number of case studies the statistics necessary to quantify the popula- tion dynamics have been derived. In other studies the effects of pike as a major fish predator on other members of the community have been docu- mented. However, because of the problems of making precise estimates from field observations, quantification is poor and can only indicate general trends. This chapter will consider population control mechanisms such as natality, mortality, recruitment, immigration and emigration. Factors which affect recruitment, both density dependent and density independent, growth and mortality of the adult population and the influence of pike in a community of fish will also be discussed.