The role of fish in marine food webs

Fish employ mostly opportunistic size-based predation alongside a diverse array of feeding strategies. They occupy a wide range of trophic levels and fulfill diverse roles in marine food webs. This chapter presents the most common modeling approaches used to study the dynamics of fish within the food web. Using one of these approaches, we estimated that fish dominate the higher trophic levels (≥3) in biomass. We then present how fish contribute to trophic controls and the stability of marine food webs. By considering jointly the feeding dynamics and mobility patterns, we describe how fish facilitate the transfer of matter between ecosystems, both horizontally and vertically. Given their diverse roles, fish constitute a key element in marine food webs and contribute to various ecosystem services. Consequently, they have a crucial role to play in the implementation of ecosystem-based management strategies.