Abstract

Zooplankton are integral to the functioning of aquatic systems, acting as the intermediary link between higher-order consumers and primary producers, specifically phytoplankton and higher-order predators, such as economically valuable fish. Their community structure, abundance, and size distribution are determinants of the efficiency of energy transfer within the aquatic food web and influence the recruitment and growth of fish, and, consequently, the fisheries. This review summarizes the current state of knowledge on the ecology of zooplankton in freshwater, estuarine, and marine systems, emphasizing the roles of temperature, nutrients, and hydrodynamics. Recent empirical evidence suggests that fluctuations in zooplankton may cause marked changes in fish yield and points to their role as bioindicators of ecosystem condition and the state of fisheries. This evidence reinforces the need to integrate zooplankton monitoring into management systems, particularly ecosystem-based fisheries management (EBFM), to inform decision-making on harvest controls, seasonal fishery closures, and habitat conservation. This paper advocates including zooplankton monitoring in fisheries management as indicators of ecosystem condition, rather than treating them as simple prey items.

Keywords: Zooplankton, Aquatic food webs, Fisheries management, Ecosystem-based management, Fish recruitment, Trophic interactions