Understanding the ecology of plankton

Plankton are microscopic organisms living in the sea. They are responsible for more than half of the biological production of our planet. They also influence global climate, fisheries and pollution. Understanding the ever-changing distribution of plankton in the ocean is one of the grand challenges of science. The scope of the problem has been well documented in the 20th century, and new research tools should greatly accelerate progress in the 21st century. A particularly promising tool is mathematical simulation of the ecosystem, in which the demographics of plankton populations are derived from the growth and behaviour of individual organisms, each responding to its immediate environment. These use new computer codes, based on the Lagrangian Ensemble method, which are at the leading edge of complexity simulation. When integrated on massively parallel computers they can simulate the individual histories of millions of plankters for several decades. These ‘virtual plankton ecosystems’ help us to understand the complex processes responsible for the ever-changing patterns of planktonic life in the ocean.