Intraguild Predation Dynamics in a Lake Ecosystem Based on a Coupled Hydrodynamic-Ecological Model: The Example of Lake Kinneret (Israel)

Abstract

The food web of Lake Kinneret contains intraguild predation (IGP). Predatory invertebrates and planktivorous fish both feed on herbivorous zooplankton, while the planktivorous fish also feed on the predatory invertebrates. In this study, a complex mechanistic hydrodynamic-ecological model, coupled to a bioenergetics-based fish population model (DYCD-FISH), was employed with the aim of revealing IGP dynamics. The results indicate that the predation pressure of predatory zooplankton on herbivorous zooplankton varies widely, depending on the season. At the time of its annual peak, it is 10–20 times higher than the fish predation pressure. When the number of fish was significantly higher, as occurs in the lake after atypical meteorological years, the effect was a shift from a bottom-up controlled ecosystem, to the top-down control of planktivorous fish and a significant reduction of predatory and herbivorous zooplankton biomass. Yet, seasonally, the decrease in predatory-zooplankton biomass was followed by a decrease in their predation pressure on herbivorous zooplankton, leading to an increase of herbivorous zooplankton biomass to an extent similar to the base level. The analysis demonstrates the emergence of non-equilibrium IGP dynamics due to intra-annual and inter-annual changes in the physico-chemical characteristics of the lake, and suggests that IGP dynamics should be considered in food web models in order to more accurately capture mass transfer and trophic interactions.

Abiotic–Biotic Interrelations in the Context of Stabilized Ecological Potential of Post-Mining Waters

“…The top-down and bottom-up effects on plankton-fish dynamics were discussed by Pal and Chatterjee [47,48], who confirmed that fish predation determines the abundance of herbivorous zooplankton, which, in turn, regulates phytoplankton biomass. However, it is also dependent on the growing season, especially due to the widely varied predatory zooplankton pressure on herbivorous zooplankton [49]. Thus, any changes in the abundance of planktivorous fish can directly affect both phytoplankton and zooplankton, but the role of omnivorous or predatory fish is also known.…”

Zooplankton Research in Lake Kinneret: A Review

“…Zooplankton is under two directive eco-forces: A) Cascading top-down pressure by zooplanktivore fishes, but invertebrate predation is negligible, and increase in the Bleak population in the lake was documented [22][23][24][25]; B) Bottom-up through nutrients controlling the available algal density and likely the zooplankton is significantly affected by temperature and temperature elevation due to climate change (Figure 14) [4,5] also supported the forceful impact on metabolic activity. This paper has focused on the relation between climate change and Zooplankton ecology.…”

The Effects of Intraguild Predation on Phytoplankton Assemblage Composition and Diversity: A Mesocosm Experiment

“…Intraguild predation (IGP) is a complex interspecific relationship prevalent in ecosystems, where two predators of the same trophic level compete for prey resources and may also act as predators of each other [ 1 ]. Intraguild predation is prevalent in various ecosystems [ 2 , 3 ]; for example, some small fish and shrimp in lake ecosystems are in competition for food resources such as zooplankton and also have predatory relationships [ 4 ].…”