Ecosystem modelling

Biological processes such as photosynthesis, the growth of phytoplankton (microscopic marine plants), can be modelled using mathematical equations relating the growth rate to factors such as light, available nutrients, etc. Further equations describe how phytoplankton is eaten by zooplankton (microscopic marine animals), transported in space by marine currents and turbulence, etc. By solving such equations in a computer model it is possible to simulate how phytoplankton biomass develops in time and space in response to external influences. These influences range from natural variability induced by the seasonal cycle of sunlight and water temperature or the current fluctuations, to the changes induced by human activities, such as the agricultural, domestic and industrial use of nitrates and phosphates which reach the marine ecosystem via rivers.

Common plankton species found in Belgian waters. Left: Phaeocystis pouchetii, a microscopic marine plant or phytoplankton that is responsible for the "dirty" foam sometimes found on beaches in spring. Right: Temora longicornis, a microscopic marine animal or zooplankton that feeds off certain phytoplankton species. © Karl Embleton, Sir Alister Hardy Foundation for Ocean Science, 1999.

 How are models developed?

 Why do we use ecosystem models?

 Results