  Plankton is the productive base of aquatic ecosystems and plays a major role
in the global control of atmospheric carbon dioxide. Nevertheless, after
intensive study, the factors that drive its spatial distribution are still far
from being clear. The models proposed so far show very limited agreement with
actual data as many of their results are not consistent with field
observations. Here we show that fluctuations and turbulent diffusion in
standard prey-predator models are able to accurately and consistently explain
plankton field observations at mesoscales (1-100 km). This includes not only
the spatial pattern but also its temporal evolution. We explicitly elucidate
the interplay between physical and biological factors, suggesting that the form
in which small scale biotic fluctuations are transferred to larger scales may
constitute one of the key elements in determining the spatial distribution of
plankton in the sea.
