The decades-old fight over genetically modified food has reached a fever pitch in Washington.

The Obama administration and Congress are weighing the safety of technological advances that seem ripped from science fiction, including salmon that can grow to full size in half the normal time and strains of crops engineered to resist powerful herbicides.

Critics of these innovations warn that they could pose threats to public health, damage the environment or, in the salmon’s case, lead to the destruction of species when gene-splicing goes wrong.