The Influence of Turbulence on Plankton Predation Strategies

✍ Scribed by D.M. LEWIS; T.J. PEDLEY

• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 474 KB
• Volume: 210
• Category: Article
• ISSN: 0022-5193
• DOI: 10.1006/jtbi.2001.2310

✦ Synopsis

The importance of predation in regulating the size of competing plankton and larval "sh populations has long been appreciated. However, it has only recently been recognized that turbulence must have a signi"cant in#uence on predator}prey interactions because most rival species of microorganisms co-exist in oceanic or fast moving fresh water #ows. Turbulence is likely to in#uence predation strategies in two ways. The extra energy imparted to a microorganism from the #ow "eld will enhance the number of encounters or &&contacts'' between predators and prey. At the same time, because the velocity of a predator relative to its potential prey will be increased, the time-scale over which a capture must be completed is reduced. Balancing the bene"ts of extra encounters with the drawbacks of more di$cult captures, will dictate an optimal predation strategy, either foraging behaviour or ambush feeding, on the predator. This will depend on its own and the prey's swimming capabilities, as well as the characteristics of the turbulent environment. In this paper some previous work, examining the increased encounter rate in turbulence, will be extended to look at the capture problem. The main proposal is that the capture event should be encapsulated in a capture probability function, from which the optimal predation strategy can be derived. As an illustration, plausible capture probability functions will be postulated and the resulting predictions tested against numerical simulations carried out in a turbulent-like #ow "eld. Good agreement between the predictions and the simulations is demonstrated.