Predation on Eggs and Larvae of Marine Fishes and the Recruitment Problem

Abstract

Publisher Summary This chapter discusses predation as a factor that may regulate levels of recruitment or generate variations in it. It also discusses predation on fish eggs and larvae as an ecological process and review what is known of its importance in the dynamics of fish populations. Only rarely has predation been recognized in past conceptual models dealing with recruitment variations, but it is increasingly viewed as an important factor influencing egg and larval survival. To manage exploited fishes, it is important to understand the causes of changes in abundance and to know whether the observed changes are natural or induced by man. Predation, including cannibalism, is especially important from a manager's perspective because it is often proposed as a cause of density-dependent regulation in stock-recruitment relationships. Multi-species interactions that focus on predator-prey relationships are of increasing interest, especially when fishing pressure on one species may influence the abundance of other species. This chapter examines predation on fish eggs and larvae by invertebrate predators and fishes. Primary focus is on mid- to high-latitude marine fishes. The chapter discusses the types of predators on fish eggs and larvae and assesses how ecological and behavioral interactions influence the vulnerability of individuals and populations. It then reviews methods and discusses problems of studying the impact of predation on egg and larval survival in the sea. In the end, there is discussion about adaptations of fishes to avoid predation on early life stages, processes of starvation versus predation, and the role of predation in regulating fish recruitment.