Movie S1.

The turbulent steady-state flow dynamics for an active fluid with small energy injection bandwidth κ= 0.63/Λ as typically observed in our 3D simulations. This simulation was performed in a cubic box of size L= 32Λ, where Λ is the typical vortex scale, using unbiased random initial conditions and periodic boundary conditions. Left shows a component of the vorticity pseudovector and Right shows the corresponding local helicity field. Note that the measured values of the helicity are predominantly positive everywhere, indicating that the flow has undergone spontaneous mirror-symmetry breaking to realize a near-Beltrami vector field. Extended chain-like clusters of high vorticity and helicity transport the energy from smaller to larger scales.