  We investigate the dynamics of the Fisher equation for the spreading of
micro-organisms in one dimension subject to both turbulent convection and
diffusion. We show that for strong enough turbulence, bacteria, for example,
track in a quasilocalized fashion (with remakably long persistance times) sinks
in the turbulent field. An important consequence is a large reduction in the
carrying capacity of the fluid medium. We determine analytically the regimes
where this quasi-localized behavior occurs and test our predictions by
numerical simulations.
